LinuxLists.cc - [PATCH] drm: move allocation out of drm_get_format

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Subject: Re: [PATCH] drm: move allocation out of drm_get_format_name()

On Saturday, 2016-11-05 13:11:36 +0100, Christian König wrote:
> Am 05.11.2016 um 02:33 schrieb Eric Engestrom:
> > +typedef char drm_format_name_buf[32];
>
> Please don't use a typedef for this, just define the maximum size of
> characters the function might write somewhere.
>
> See the kernel coding style as well:
> > In general, a pointer, or a struct that has elements that can reasonably
> > be directly accessed should **never** be a typedef.
>

I would normally agree as I tend to hate typedefs ($DAYJOB {ab,mis}uses
them way too much), and your way was what I wrote at first, but Rob Clark's
typedef idea makes it much harder for someone to allocate a buffer of
the wrong size, which IMO is good thing here.

I can rewrite the typedef out if you think it's better.

Cheers,
Eric

2016-11-05 16:49:05

by Rob Clark

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Subject: Re: [PATCH] drm: move allocation out of drm_get_format_name()

On Sat, Nov 5, 2016 at 12:38 PM, Eric Engestrom <[email protected]> wrote:
> On Saturday, 2016-11-05 13:11:36 +0100, Christian König wrote:
>> Am 05.11.2016 um 02:33 schrieb Eric Engestrom:
>> > +typedef char drm_format_name_buf[32];
>>
>> Please don't use a typedef for this, just define the maximum size of
>> characters the function might write somewhere.
>>
>> See the kernel coding style as well:
>> > In general, a pointer, or a struct that has elements that can reasonably
>> > be directly accessed should **never** be a typedef.
>>
>
> I would normally agree as I tend to hate typedefs ($DAYJOB {ab,mis}uses
> them way too much), and your way was what I wrote at first, but Rob Clark's
> typedef idea makes it much harder for someone to allocate a buffer of
> the wrong size, which IMO is good thing here.

IMHO I would make a small test program to verify this actually helps
the compiler catch problems. And if it does, I would stick with it.
The coding-style should be guidelines, not something that supersedes
common sense / practicality.

That is my $0.02 anyways.. if others vehemently disagree and want to
dogmatically stick to the coding-style guidelines, ok then. OTOH, if
this approach doesn't help the compiler catch issues, then it isn't
worth it.

BR,
-R

> I can rewrite the typedef out if you think it's better.
>
> Cheers,
> Eric
> _______________________________________________
> dri-devel mailing list
> [email protected]
> https://lists.freedesktop.org/mailman/listinfo/dri-devel

2016-11-06 09:47:43

by Christian König

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Subject: Re: [PATCH] drm: move allocation out of drm_get_format_name()

Am 05.11.2016 um 17:49 schrieb Rob Clark:
> On Sat, Nov 5, 2016 at 12:38 PM, Eric Engestrom <[email protected]> wrote:
>> On Saturday, 2016-11-05 13:11:36 +0100, Christian König wrote:
>>> Am 05.11.2016 um 02:33 schrieb Eric Engestrom:
>>>> +typedef char drm_format_name_buf[32];
>>> Please don't use a typedef for this, just define the maximum size of
>>> characters the function might write somewhere.
>>>
>>> See the kernel coding style as well:
>>>> In general, a pointer, or a struct that has elements that can reasonably
>>>> be directly accessed should **never** be a typedef.
>> I would normally agree as I tend to hate typedefs ($DAYJOB {ab,mis}uses
>> them way too much), and your way was what I wrote at first, but Rob Clark's
>> typedef idea makes it much harder for someone to allocate a buffer of
>> the wrong size, which IMO is good thing here.
> IMHO I would make a small test program to verify this actually helps
> the compiler catch problems. And if it does, I would stick with it.
> The coding-style should be guidelines, not something that supersedes
> common sense / practicality.

Well completely agree that we should be able to question the coding
style rules, but when we do it we discuss this on a the mailing list
first and then start to use it in code. Not the other way around.

>
> That is my $0.02 anyways.. if others vehemently disagree and want to
> dogmatically stick to the coding-style guidelines, ok then. OTOH, if
> this approach doesn't help the compiler catch issues, then it isn't
> worth it.

Yeah, exactly that's the point. If I'm not completely mistaken the
compiler won't issue a warning here if you pass an array with the wrong
size.

I think you need something like "struct drm_format_name_buf { char
str[32]; };" to trigger this.

Apart from that is this function really called so often that using
kasprintf() is a problem here? Or is there another motivation behind the
change?

Regards,
Christian.

>
> BR,
> -R
>
>> I can rewrite the typedef out if you think it's better.
>>
>> Cheers,
>> Eric
>> _______________________________________________
>> dri-devel mailing list
>> [email protected]
>> https://lists.freedesktop.org/mailman/listinfo/dri-devel

2016-11-06 13:03:50

by Rob Clark

[permalink] [raw]

Subject: Re: [PATCH] drm: move allocation out of drm_get_format_name()

On Sun, Nov 6, 2016 at 4:47 AM, Christian König
<[email protected]> wrote:
> Am 05.11.2016 um 17:49 schrieb Rob Clark:
>>
>> On Sat, Nov 5, 2016 at 12:38 PM, Eric Engestrom <[email protected]> wrote:
>>>
>>> On Saturday, 2016-11-05 13:11:36 +0100, Christian König wrote:
>>>>
>>>> Am 05.11.2016 um 02:33 schrieb Eric Engestrom:
>>>>>
>>>>> +typedef char drm_format_name_buf[32];
>>>>
>>>> Please don't use a typedef for this, just define the maximum size of
>>>> characters the function might write somewhere.
>>>>
>>>> See the kernel coding style as well:
>>>>>
>>>>> In general, a pointer, or a struct that has elements that can
>>>>> reasonably
>>>>> be directly accessed should **never** be a typedef.
>>>
>>> I would normally agree as I tend to hate typedefs ($DAYJOB {ab,mis}uses
>>> them way too much), and your way was what I wrote at first, but Rob
>>> Clark's
>>> typedef idea makes it much harder for someone to allocate a buffer of
>>> the wrong size, which IMO is good thing here.
>>
>> IMHO I would make a small test program to verify this actually helps
>> the compiler catch problems. And if it does, I would stick with it.
>> The coding-style should be guidelines, not something that supersedes
>> common sense / practicality.
>
>
> Well completely agree that we should be able to question the coding style
> rules, but when we do it we discuss this on a the mailing list first and
> then start to use it in code. Not the other way around.

if I'm not mistaken, that is what we are doing ;-)

>>
>> That is my $0.02 anyways.. if others vehemently disagree and want to
>> dogmatically stick to the coding-style guidelines, ok then. OTOH, if
>> this approach doesn't help the compiler catch issues, then it isn't
>> worth it.
>
>
> Yeah, exactly that's the point. If I'm not completely mistaken the compiler
> won't issue a warning here if you pass an array with the wrong size.
>
> I think you need something like "struct drm_format_name_buf { char str[32];
> };" to trigger this.

hmm, actually the struct is a nice idea then if the compiler wouldn't
catch the wrong-size-array

> Apart from that is this function really called so often that using
> kasprintf() is a problem here? Or is there another motivation behind the
> change?

Two things trouble me about the kasprintf approach.. (ignoring the
fact that atm it is not GFP_ATOMIC)
1) you can't do DRM_DEBUG("format: %s\n", drm_get_format_name(..)) so
it pulls the memory allocation and sprintf outside of the drm_debug
check
2) seems awfully easy to forget the kfree... I wouldn't have even
known that now you need to free the result (with some patches I'm
working on) if it weren't for the fact that lockdep alerted me to the
GFP_KERNEL allocation in atomic ctx ;-)

BR,
-R

> Regards,
> Christian.
>
>
>>
>> BR,
>> -R
>>
>>> I can rewrite the typedef out if you think it's better.
>>>
>>> Cheers,
>>> Eric
>>> _______________________________________________
>>> dri-devel mailing list
>>> [email protected]
>>> https://lists.freedesktop.org/mailman/listinfo/dri-devel
>
>
>

2016-11-07 00:48:44

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Subject: [PATCH v2] drm: move allocation out of drm_get_format_name()

Fixes: 90844f00049e9f42573fd31d7c32e8fd31d3fd07

drm: make drm_get_format_name thread-safe

Signed-off-by: Eric Engestrom <[email protected]>
[danvet: Clarify that the returned pointer must be freed with
kfree().]
Signed-off-by: Daniel Vetter <[email protected]>

Cc: Rob Clark <[email protected]>
Cc: Christian König <[email protected]>
Suggested-by: Ville Syrjälä <[email protected]>
Signed-off-by: Eric Engestrom <[email protected]>
---

v2: use single-field struct instead of typedef to let the compiler
enforce the type (Christian König)

---
include/drm/drm_fourcc.h | 10 +++++-
drivers/gpu/drm/drm_fourcc.c | 14 +++------
drivers/gpu/drm/amd/amdgpu/dce_v10_0.c | 7 ++---
drivers/gpu/drm/amd/amdgpu/dce_v11_0.c | 7 ++---
drivers/gpu/drm/amd/amdgpu/dce_v6_0.c | 3 +-
drivers/gpu/drm/amd/amdgpu/dce_v8_0.c | 7 ++---
drivers/gpu/drm/drm_atomic.c | 7 +++--
drivers/gpu/drm/drm_crtc.c | 7 +++--
drivers/gpu/drm/drm_framebuffer.c | 7 +++--
drivers/gpu/drm/drm_modeset_helper.c | 7 +++--
drivers/gpu/drm/drm_plane.c | 7 +++--
drivers/gpu/drm/hisilicon/kirin/kirin_drm_ade.c | 7 ++---
drivers/gpu/drm/i915/i915_debugfs.c | 10 +++---
drivers/gpu/drm/i915/intel_atomic_plane.c | 8 ++---
drivers/gpu/drm/i915/intel_display.c | 41 ++++++++++---------------
drivers/gpu/drm/radeon/atombios_crtc.c | 14 ++++-----
drivers/gpu/drm/vmwgfx/vmwgfx_kms.c | 3 +-
17 files changed, 80 insertions(+), 86 deletions(-)

diff --git a/include/drm/drm_fourcc.h b/include/drm/drm_fourcc.h
index dc0aafa..4b03ca0 100644
--- a/include/drm/drm_fourcc.h
+++ b/include/drm/drm_fourcc.h
@@ -45,6 +45,14 @@ struct drm_format_info {
u8 vsub;
};

+/**
+ * struct drm_format_name_buf - name of a DRM format
+ * @str: string buffer containing the format name
+ */
+struct drm_format_name_buf {
+ char str[32];
+};
+
const struct drm_format_info *__drm_format_info(u32 format);
const struct drm_format_info *drm_format_info(u32 format);
uint32_t drm_mode_legacy_fb_format(uint32_t bpp, uint32_t depth);
@@ -54,6 +62,6 @@ int drm_format_horz_chroma_subsampling(uint32_t format);
int drm_format_vert_chroma_subsampling(uint32_t format);
int drm_format_plane_width(int width, uint32_t format, int plane);
int drm_format_plane_height(int height, uint32_t format, int plane);
-char *drm_get_format_name(uint32_t format) __malloc;
+char *drm_get_format_name(uint32_t format, struct drm_format_name_buf *buf);

#endif /* __DRM_FOURCC_H__ */
diff --git a/drivers/gpu/drm/drm_fourcc.c b/drivers/gpu/drm/drm_fourcc.c
index cbb8b77..99b0b60 100644
--- a/drivers/gpu/drm/drm_fourcc.c
+++ b/drivers/gpu/drm/drm_fourcc.c
@@ -79,17 +79,13 @@ uint32_t drm_mode_legacy_fb_format(uint32_t bpp, uint32_t depth)
EXPORT_SYMBOL(drm_mode_legacy_fb_format);

/**
- * drm_get_format_name - return a string for drm fourcc format
+ * drm_get_format_name - fill a string with a drm fourcc format's name
* @format: format to compute name of
+ * @buf: caller-supplied buffer
- *
- * Note that the buffer returned by this function is owned by the caller
- * and will need to be freed using kfree().
*/
-char *drm_get_format_name(uint32_t format)
+char *drm_get_format_name(uint32_t format, struct drm_format_name_buf *buf)
{
- char *buf = kmalloc(32, GFP_KERNEL);
-
- snprintf(buf, 32,
+ snprintf(buf->str, sizeof(buf->str),
"%c%c%c%c %s-endian (0x%08x)",
printable_char(format & 0xff),
printable_char((format >> 8) & 0xff),
@@ -98,7 +94,7 @@ char *drm_get_format_name(uint32_t format)
format & DRM_FORMAT_BIG_ENDIAN ? "big" : "little",
format);

- return buf;
+ return buf->str;
}
EXPORT_SYMBOL(drm_get_format_name);

diff --git a/drivers/gpu/drm/amd/amdgpu/dce_v10_0.c b/drivers/gpu/drm/amd/amdgpu/dce_v10_0.c
index 199d3f7..2924cdd 100644
--- a/drivers/gpu/drm/amd/amdgpu/dce_v10_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/dce_v10_0.c
@@ -2032,7 +2032,7 @@ static int dce_v10_0_crtc_do_set_base(struct drm_crtc *crtc,
u32 tmp, viewport_w, viewport_h;
int r;
bool bypass_lut = false;
- char *format_name;
+ struct drm_format_name_buf format_name;

/* no fb bound */
if (!atomic && !crtc->primary->fb) {
@@ -2144,9 +2144,8 @@ static int dce_v10_0_crtc_do_set_base(struct drm_crtc *crtc,
bypass_lut = true;
break;
default:
- format_name = drm_get_format_name(target_fb->pixel_format);
- DRM_ERROR("Unsupported screen format %s\n", format_name);
+ DRM_ERROR("Unsupported screen format %s\n",
+ drm_get_format_name(target_fb->pixel_format, &format_name));
- kfree(format_name);
return -EINVAL;
}

diff --git a/drivers/gpu/drm/amd/amdgpu/dce_v11_0.c b/drivers/gpu/drm/amd/amdgpu/dce_v11_0.c
index ecd000e..f0e3c5c 100644
--- a/drivers/gpu/drm/amd/amdgpu/dce_v11_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/dce_v11_0.c
@@ -2013,7 +2013,7 @@ static int dce_v11_0_crtc_do_set_base(struct drm_crtc *crtc,
u32 tmp, viewport_w, viewport_h;
int r;
bool bypass_lut = false;
- char *format_name;
+ struct drm_format_name_buf format_name;

/* no fb bound */
if (!atomic && !crtc->primary->fb) {
@@ -2125,9 +2125,8 @@ static int dce_v11_0_crtc_do_set_base(struct drm_crtc *crtc,
bypass_lut = true;
break;
default:
- format_name = drm_get_format_name(target_fb->pixel_format);
- DRM_ERROR("Unsupported screen format %s\n", format_name);
+ DRM_ERROR("Unsupported screen format %s\n",
+ drm_get_format_name(target_fb->pixel_format, &format_name));
- kfree(format_name);
return -EINVAL;
}

diff --git a/drivers/gpu/drm/amd/amdgpu/dce_v6_0.c b/drivers/gpu/drm/amd/amdgpu/dce_v6_0.c
index 44547f9..5c6b82f 100644
--- a/drivers/gpu/drm/amd/amdgpu/dce_v6_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/dce_v6_0.c
@@ -1456,6 +1456,7 @@ static int dce_v6_0_crtc_do_set_base(struct drm_crtc *crtc,
u32 viewport_w, viewport_h;
int r;
bool bypass_lut = false;
+ struct drm_format_name_buf format_name;

/* no fb bound */
if (!atomic && !crtc->primary->fb) {
@@ -1559,7 +1560,7 @@ static int dce_v6_0_crtc_do_set_base(struct drm_crtc *crtc,
break;
default:
DRM_ERROR("Unsupported screen format %s\n",
- drm_get_format_name(target_fb->pixel_format));
+ drm_get_format_name(target_fb->pixel_format, &format_name));
return -EINVAL;
}

diff --git a/drivers/gpu/drm/amd/amdgpu/dce_v8_0.c b/drivers/gpu/drm/amd/amdgpu/dce_v8_0.c
index 979aedf..5aef19d 100644
--- a/drivers/gpu/drm/amd/amdgpu/dce_v8_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/dce_v8_0.c
@@ -1910,7 +1910,7 @@ static int dce_v8_0_crtc_do_set_base(struct drm_crtc *crtc,
u32 viewport_w, viewport_h;
int r;
bool bypass_lut = false;
- char *format_name;
+ struct drm_format_name_buf format_name;

/* no fb bound */
if (!atomic && !crtc->primary->fb) {
@@ -2015,9 +2015,8 @@ static int dce_v8_0_crtc_do_set_base(struct drm_crtc *crtc,
bypass_lut = true;
break;
default:
- format_name = drm_get_format_name(target_fb->pixel_format);
- DRM_ERROR("Unsupported screen format %s\n", format_name);
+ DRM_ERROR("Unsupported screen format %s\n",
+ drm_get_format_name(target_fb->pixel_format, &format_name));
- kfree(format_name);
return -EINVAL;
}

diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c
index c32fb3c..f29d3c5 100644
--- a/drivers/gpu/drm/drm_atomic.c
+++ b/drivers/gpu/drm/drm_atomic.c
@@ -835,9 +835,10 @@ static int drm_atomic_plane_check(struct drm_plane *plane,
/* Check whether this plane supports the fb pixel format. */
ret = drm_plane_check_pixel_format(plane, state->fb->pixel_format);
if (ret) {
- char *format_name = drm_get_format_name(state->fb->pixel_format);
- DRM_DEBUG_ATOMIC("Invalid pixel format %s\n", format_name);
+ struct drm_format_name_buf format_name;
+ DRM_DEBUG_ATOMIC("Invalid pixel format %s\n",
+ drm_get_format_name(state->fb->pixel_format,
+ &format_name));
- kfree(format_name);
return ret;
}

diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
index 13441e2..08ac216 100644
--- a/drivers/gpu/drm/drm_crtc.c
+++ b/drivers/gpu/drm/drm_crtc.c
@@ -827,9 +827,10 @@ int drm_mode_setcrtc(struct drm_device *dev, void *data,
ret = drm_plane_check_pixel_format(crtc->primary,
fb->pixel_format);
if (ret) {
- char *format_name = drm_get_format_name(fb->pixel_format);
- DRM_DEBUG_KMS("Invalid pixel format %s\n", format_name);
+ struct drm_format_name_buf format_name;
+ DRM_DEBUG_KMS("Invalid pixel format %s\n",
+ drm_get_format_name(fb->pixel_format,
+ &format_name));
- kfree(format_name);
goto out;
}
}
diff --git a/drivers/gpu/drm/drm_framebuffer.c b/drivers/gpu/drm/drm_framebuffer.c
index 49fd7db..df6b180 100644
--- a/drivers/gpu/drm/drm_framebuffer.c
+++ b/drivers/gpu/drm/drm_framebuffer.c
@@ -133,9 +133,10 @@ static int framebuffer_check(const struct drm_mode_fb_cmd2 *r)

info = __drm_format_info(r->pixel_format & ~DRM_FORMAT_BIG_ENDIAN);
if (!info) {
- char *format_name = drm_get_format_name(r->pixel_format);
- DRM_DEBUG_KMS("bad framebuffer format %s\n", format_name);
+ struct drm_format_name_buf format_name;
+ DRM_DEBUG_KMS("bad framebuffer format %s\n",
+ drm_get_format_name(r->pixel_format,
+ &format_name));
- kfree(format_name);
return -EINVAL;
}

diff --git a/drivers/gpu/drm/drm_modeset_helper.c b/drivers/gpu/drm/drm_modeset_helper.c
index 2544dfe..2f452b3 100644
--- a/drivers/gpu/drm/drm_modeset_helper.c
+++ b/drivers/gpu/drm/drm_modeset_helper.c
@@ -75,10 +75,11 @@ void drm_helper_mode_fill_fb_struct(struct drm_framebuffer *fb,

info = drm_format_info(mode_cmd->pixel_format);
if (!info || !info->depth) {
- char *format_name = drm_get_format_name(mode_cmd->pixel_format);
+ struct drm_format_name_buf format_name;

- DRM_DEBUG_KMS("non-RGB pixel format %s\n", format_name);
+ DRM_DEBUG_KMS("non-RGB pixel format %s\n",
+ drm_get_format_name(mode_cmd->pixel_format,
+ &format_name));
- kfree(format_name);

fb->depth = 0;
fb->bits_per_pixel = 0;
diff --git a/drivers/gpu/drm/drm_plane.c b/drivers/gpu/drm/drm_plane.c
index 249c0ae..2ba0c22 100644
--- a/drivers/gpu/drm/drm_plane.c
+++ b/drivers/gpu/drm/drm_plane.c
@@ -479,9 +479,10 @@ static int __setplane_internal(struct drm_plane *plane,
/* Check whether this plane supports the fb pixel format. */
ret = drm_plane_check_pixel_format(plane, fb->pixel_format);
if (ret) {
- char *format_name = drm_get_format_name(fb->pixel_format);
- DRM_DEBUG_KMS("Invalid pixel format %s\n", format_name);
+ struct drm_format_name_buf format_name;
+ DRM_DEBUG_KMS("Invalid pixel format %s\n",
+ drm_get_format_name(fb->pixel_format,
+ &format_name));
- kfree(format_name);
goto out;
}

diff --git a/drivers/gpu/drm/hisilicon/kirin/kirin_drm_ade.c b/drivers/gpu/drm/hisilicon/kirin/kirin_drm_ade.c
index 7e7a4d4..afc2b5d 100644
--- a/drivers/gpu/drm/hisilicon/kirin/kirin_drm_ade.c
+++ b/drivers/gpu/drm/hisilicon/kirin/kirin_drm_ade.c
@@ -608,17 +608,16 @@ static void ade_rdma_set(void __iomem *base, struct drm_framebuffer *fb,
u32 ch, u32 y, u32 in_h, u32 fmt)
{
struct drm_gem_cma_object *obj = drm_fb_cma_get_gem_obj(fb, 0);
- char *format_name;
+ struct drm_format_name_buf format_name;
u32 reg_ctrl, reg_addr, reg_size, reg_stride, reg_space, reg_en;
u32 stride = fb->pitches[0];
u32 addr = (u32)obj->paddr + y * stride;

DRM_DEBUG_DRIVER("rdma%d: (y=%d, height=%d), stride=%d, paddr=0x%x\n",
ch + 1, y, in_h, stride, (u32)obj->paddr);
- format_name = drm_get_format_name(fb->pixel_format);
DRM_DEBUG_DRIVER("addr=0x%x, fb:%dx%d, pixel_format=%d(%s)\n",
- addr, fb->width, fb->height, fmt, format_name);
+ addr, fb->width, fb->height, fmt,
+ drm_get_format_name(fb->pixel_format, &format_name));
- kfree(format_name);

/* get reg offset */
reg_ctrl = RD_CH_CTRL(ch);
diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
index 20638d2..670423e 100644
--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -2971,7 +2971,7 @@ static void intel_plane_info(struct seq_file *m, struct intel_crtc *intel_crtc)
for_each_intel_plane_on_crtc(dev, intel_crtc, intel_plane) {
struct drm_plane_state *state;
struct drm_plane *plane = &intel_plane->base;
- char *format_name;
+ struct drm_format_name_buf format_name;

if (!plane->state) {
seq_puts(m, "plane->state is NULL!\n");
@@ -2981,9 +2981,9 @@ static void intel_plane_info(struct seq_file *m, struct intel_crtc *intel_crtc)
state = plane->state;

if (state->fb) {
- format_name = drm_get_format_name(state->fb->pixel_format);
+ drm_get_format_name(state->fb->pixel_format, &format_name);
} else {
- format_name = kstrdup("N/A", GFP_KERNEL);
+ sprintf(format_name.str, "N/A");
}

seq_printf(m, "\t--Plane id %d: type=%s, crtc_pos=%4dx%4d, crtc_size=%4dx%4d, src_pos=%d.%04ux%d.%04u, src_size=%d.%04ux%d.%04u, format=%s, rotation=%s\n",
@@ -2999,10 +2999,8 @@ static void intel_plane_info(struct seq_file *m, struct intel_crtc *intel_crtc)
((state->src_w & 0xffff) * 15625) >> 10,
(state->src_h >> 16),
((state->src_h & 0xffff) * 15625) >> 10,
- format_name,
+ format_name.str,
plane_rotation(state->rotation));
-
- kfree(format_name);
}
}

diff --git a/drivers/gpu/drm/i915/intel_atomic_plane.c b/drivers/gpu/drm/i915/intel_atomic_plane.c
index c762ae5..6c76e3d 100644
--- a/drivers/gpu/drm/i915/intel_atomic_plane.c
+++ b/drivers/gpu/drm/i915/intel_atomic_plane.c
@@ -143,7 +143,7 @@ static int intel_plane_atomic_check(struct drm_plane *plane,
crtc_state->base.enable ? crtc_state->pipe_src_h : 0;

if (state->fb && drm_rotation_90_or_270(state->rotation)) {
- char *format_name;
+ struct drm_format_name_buf format_name;

if (!(state->fb->modifier[0] == I915_FORMAT_MOD_Y_TILED ||
state->fb->modifier[0] == I915_FORMAT_MOD_Yf_TILED)) {
@@ -159,9 +159,9 @@ static int intel_plane_atomic_check(struct drm_plane *plane,
switch (state->fb->pixel_format) {
case DRM_FORMAT_C8:
case DRM_FORMAT_RGB565:
- format_name = drm_get_format_name(state->fb->pixel_format);
- DRM_DEBUG_KMS("Unsupported pixel format %s for 90/270!\n", format_name);
+ DRM_DEBUG_KMS("Unsupported pixel format %s for 90/270!\n",
+ drm_get_format_name(state->fb->pixel_format,
+ &format_name));
- kfree(format_name);
return -EINVAL;

default:
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 6f8f6ec..8209170 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -12871,7 +12871,7 @@ static void intel_dump_pipe_config(struct intel_crtc *crtc,

DRM_DEBUG_KMS("planes on this crtc\n");
list_for_each_entry(plane, &dev->mode_config.plane_list, head) {
- char *format_name;
+ struct drm_format_name_buf format_name;
intel_plane = to_intel_plane(plane);
if (intel_plane->pipe != crtc->pipe)
continue;
@@ -12884,12 +12884,11 @@ static void intel_dump_pipe_config(struct intel_crtc *crtc,
continue;
}

- format_name = drm_get_format_name(fb->pixel_format);
-
DRM_DEBUG_KMS("[PLANE:%d:%s] enabled",
plane->base.id, plane->name);
DRM_DEBUG_KMS("\tFB:%d, fb = %ux%u format = %s",
- fb->base.id, fb->width, fb->height, format_name);
+ fb->base.id, fb->width, fb->height,
+ drm_get_format_name(fb->pixel_format, &format_name));
DRM_DEBUG_KMS("\tscaler:%d src %dx%d+%d+%d dst %dx%d+%d+%d\n",
state->scaler_id,
state->base.src.x1 >> 16,
@@ -12899,8 +12898,6 @@ static void intel_dump_pipe_config(struct intel_crtc *crtc,
state->base.dst.x1, state->base.dst.y1,
drm_rect_width(&state->base.dst),
drm_rect_height(&state->base.dst));
-
- kfree(format_name);
}
}

@@ -15749,7 +15746,7 @@ static int intel_framebuffer_init(struct drm_device *dev,
unsigned int tiling = i915_gem_object_get_tiling(obj);
int ret;
u32 pitch_limit, stride_alignment;
- char *format_name;
+ struct drm_format_name_buf format_name;

WARN_ON(!mutex_is_locked(&dev->struct_mutex));

@@ -15840,18 +15837,16 @@ static int intel_framebuffer_init(struct drm_device *dev,
break;
case DRM_FORMAT_XRGB1555:
if (INTEL_INFO(dev)->gen > 3) {
- format_name = drm_get_format_name(mode_cmd->pixel_format);
- DRM_DEBUG("unsupported pixel format: %s\n", format_name);
+ DRM_DEBUG("unsupported pixel format: %s\n",
+ drm_get_format_name(mode_cmd->pixel_format, &format_name));
- kfree(format_name);
return -EINVAL;
}
break;
case DRM_FORMAT_ABGR8888:
if (!IS_VALLEYVIEW(dev_priv) && !IS_CHERRYVIEW(dev_priv) &&
INTEL_INFO(dev)->gen < 9) {
- format_name = drm_get_format_name(mode_cmd->pixel_format);
- DRM_DEBUG("unsupported pixel format: %s\n", format_name);
+ DRM_DEBUG("unsupported pixel format: %s\n",
+ drm_get_format_name(mode_cmd->pixel_format, &format_name));
- kfree(format_name);
return -EINVAL;
}
break;
@@ -15859,17 +15854,15 @@ static int intel_framebuffer_init(struct drm_device *dev,
case DRM_FORMAT_XRGB2101010:
case DRM_FORMAT_XBGR2101010:
if (INTEL_INFO(dev)->gen < 4) {
- format_name = drm_get_format_name(mode_cmd->pixel_format);
- DRM_DEBUG("unsupported pixel format: %s\n", format_name);
+ DRM_DEBUG("unsupported pixel format: %s\n",
+ drm_get_format_name(mode_cmd->pixel_format, &format_name));
- kfree(format_name);
return -EINVAL;
}
break;
case DRM_FORMAT_ABGR2101010:
if (!IS_VALLEYVIEW(dev_priv) && !IS_CHERRYVIEW(dev_priv)) {
- format_name = drm_get_format_name(mode_cmd->pixel_format);
- DRM_DEBUG("unsupported pixel format: %s\n", format_name);
+ DRM_DEBUG("unsupported pixel format: %s\n",
+ drm_get_format_name(mode_cmd->pixel_format, &format_name));
- kfree(format_name);
return -EINVAL;
}
break;
@@ -15878,16 +15871,14 @@ static int intel_framebuffer_init(struct drm_device *dev,
case DRM_FORMAT_YVYU:
case DRM_FORMAT_VYUY:
if (INTEL_INFO(dev)->gen < 5) {
- format_name = drm_get_format_name(mode_cmd->pixel_format);
- DRM_DEBUG("unsupported pixel format: %s\n", format_name);
+ DRM_DEBUG("unsupported pixel format: %s\n",
+ drm_get_format_name(mode_cmd->pixel_format, &format_name));
- kfree(format_name);
return -EINVAL;
}
break;
default:
- format_name = drm_get_format_name(mode_cmd->pixel_format);
- DRM_DEBUG("unsupported pixel format: %s\n", format_name);
+ DRM_DEBUG("unsupported pixel format: %s\n",
+ drm_get_format_name(mode_cmd->pixel_format, &format_name));
- kfree(format_name);
return -EINVAL;
}

diff --git a/drivers/gpu/drm/radeon/atombios_crtc.c b/drivers/gpu/drm/radeon/atombios_crtc.c
index 74f99ba..05f4ebe 100644
--- a/drivers/gpu/drm/radeon/atombios_crtc.c
+++ b/drivers/gpu/drm/radeon/atombios_crtc.c
@@ -1156,7 +1156,7 @@ static int dce4_crtc_do_set_base(struct drm_crtc *crtc,
u32 tmp, viewport_w, viewport_h;
int r;
bool bypass_lut = false;
- char *format_name;
+ struct drm_format_name_buf format_name;

/* no fb bound */
if (!atomic && !crtc->primary->fb) {
@@ -1260,9 +1260,8 @@ static int dce4_crtc_do_set_base(struct drm_crtc *crtc,
bypass_lut = true;
break;
default:
- format_name = drm_get_format_name(target_fb->pixel_format);
- DRM_ERROR("Unsupported screen format %s\n", format_name);
+ DRM_ERROR("Unsupported screen format %s\n",
+ drm_get_format_name(target_fb->pixel_format, &format_name));
- kfree(format_name);
return -EINVAL;
}

@@ -1473,7 +1472,7 @@ static int avivo_crtc_do_set_base(struct drm_crtc *crtc,
u32 viewport_w, viewport_h;
int r;
bool bypass_lut = false;
- char *format_name;
+ struct drm_format_name_buf format_name;

/* no fb bound */
if (!atomic && !crtc->primary->fb) {
@@ -1563,9 +1562,8 @@ static int avivo_crtc_do_set_base(struct drm_crtc *crtc,
bypass_lut = true;
break;
default:
- format_name = drm_get_format_name(target_fb->pixel_format);
- DRM_ERROR("Unsupported screen format %s\n", format_name);
+ DRM_ERROR("Unsupported screen format %s\n",
+ drm_get_format_name(target_fb->pixel_format, &format_name));
- kfree(format_name);
return -EINVAL;
}

diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c b/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c
index c965514..e3f68cc 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c
@@ -985,8 +985,9 @@ static struct drm_framebuffer *vmw_kms_fb_create(struct drm_device *dev,

info = drm_format_info(mode_cmd2->pixel_format);
if (!info || !info->depth) {
+ struct drm_format_name_buf format_name;
DRM_ERROR("Unsupported framebuffer format %s\n",
- drm_get_format_name(mode_cmd2->pixel_format));
+ drm_get_format_name(mode_cmd2->pixel_format, &format_name));
return ERR_PTR(-EINVAL);
}

--
Cheers,
Eric

2016-11-07 01:15:06

[permalink] [raw]

Subject: Re: [PATCH] drm: move allocation out of drm_get_format_name()

On Sunday, 2016-11-06 08:03:47 -0500, Rob Clark wrote:
> On Sun, Nov 6, 2016 at 4:47 AM, Christian König
> <[email protected]> wrote:
> > Am 05.11.2016 um 17:49 schrieb Rob Clark:
> >>
> >> On Sat, Nov 5, 2016 at 12:38 PM, Eric Engestrom <[email protected]> wrote:
> >>>
> >>> On Saturday, 2016-11-05 13:11:36 +0100, Christian König wrote:
> >>>>
> >>>> Am 05.11.2016 um 02:33 schrieb Eric Engestrom:
> >>>>>
> >>>>> +typedef char drm_format_name_buf[32];
> >>>>
> >>>> Please don't use a typedef for this, just define the maximum size of
> >>>> characters the function might write somewhere.
> >>>>
> >>>> See the kernel coding style as well:
> >>>>>
> >>>>> In general, a pointer, or a struct that has elements that can
> >>>>> reasonably
> >>>>> be directly accessed should **never** be a typedef.
> >>>
> >>> I would normally agree as I tend to hate typedefs ($DAYJOB {ab,mis}uses
> >>> them way too much), and your way was what I wrote at first, but Rob
> >>> Clark's
> >>> typedef idea makes it much harder for someone to allocate a buffer of
> >>> the wrong size, which IMO is good thing here.
> >>
> >> IMHO I would make a small test program to verify this actually helps
> >> the compiler catch problems. And if it does, I would stick with it.
> >> The coding-style should be guidelines, not something that supersedes
> >> common sense / practicality.
> >
> >
> > Well completely agree that we should be able to question the coding style
> > rules, but when we do it we discuss this on a the mailing list first and
> > then start to use it in code. Not the other way around.
>
> if I'm not mistaken, that is what we are doing ;-)
>
> >>
> >> That is my $0.02 anyways.. if others vehemently disagree and want to
> >> dogmatically stick to the coding-style guidelines, ok then. OTOH, if
> >> this approach doesn't help the compiler catch issues, then it isn't
> >> worth it.
> >
> >
> > Yeah, exactly that's the point. If I'm not completely mistaken the compiler
> > won't issue a warning here if you pass an array with the wrong size.
> >
> > I think you need something like "struct drm_format_name_buf { char str[32];
> > };" to trigger this.
>
> hmm, actually the struct is a nice idea then if the compiler wouldn't
> catch the wrong-size-array

Sending the patch in a minute.

>
> > apart from that is this function really called so often that using
> > kasprintf() is a problem here? or is there another motivation behind the
> > change?
>
> two things trouble me about the kasprintf approach.. (ignoring the
> fact that atm it is not gfp_atomic)
> 1) you can't do drm_debug("format: %s\n", drm_get_format_name(..)) so
> it pulls the memory allocation and sprintf outside of the drm_debug
> check
> 2) seems awfully easy to forget the kfree...

I actually found a couple of these memory leaks while doing this patch,
look for files where i don't remove kfree :)
(eg. vmwgfx at the end of the patch)

> i wouldn't have even
> known that now you need to free the result (with some patches i'm
> working on) if it weren't for the fact that lockdep alerted me to the
> gfp_kernel allocation in atomic ctx ;-)
>
> br,
> -r

2016-11-07 07:47:13

by Christian König

[permalink] [raw]

Subject: Re: [PATCH v2] drm: move allocation out of drm_get_format_name()

Am 07.11.2016 um 01:48 schrieb Eric Engestrom:
> Fixes: 90844f00049e9f42573fd31d7c32e8fd31d3fd07
>
> drm: make drm_get_format_name thread-safe
>
> Signed-off-by: Eric Engestrom <[email protected]>
> [danvet: Clarify that the returned pointer must be freed with
> kfree().]
> Signed-off-by: Daniel Vetter <[email protected]>
>
> Cc: Rob Clark <[email protected]>
> Cc: Christian König <[email protected]>
> Suggested-by: Ville Syrjälä <[email protected]>
> Signed-off-by: Eric Engestrom <[email protected]>
Acked-by: Christian König <[email protected]>.

> ---
>
> v2: use single-field struct instead of typedef to let the compiler
> enforce the type (Christian König)
>
> ---
> include/drm/drm_fourcc.h | 10 +++++-
> drivers/gpu/drm/drm_fourcc.c | 14 +++------
> drivers/gpu/drm/amd/amdgpu/dce_v10_0.c | 7 ++---
> drivers/gpu/drm/amd/amdgpu/dce_v11_0.c | 7 ++---
> drivers/gpu/drm/amd/amdgpu/dce_v6_0.c | 3 +-
> drivers/gpu/drm/amd/amdgpu/dce_v8_0.c | 7 ++---
> drivers/gpu/drm/drm_atomic.c | 7 +++--
> drivers/gpu/drm/drm_crtc.c | 7 +++--
> drivers/gpu/drm/drm_framebuffer.c | 7 +++--
> drivers/gpu/drm/drm_modeset_helper.c | 7 +++--
> drivers/gpu/drm/drm_plane.c | 7 +++--
> drivers/gpu/drm/hisilicon/kirin/kirin_drm_ade.c | 7 ++---
> drivers/gpu/drm/i915/i915_debugfs.c | 10 +++---
> drivers/gpu/drm/i915/intel_atomic_plane.c | 8 ++---
> drivers/gpu/drm/i915/intel_display.c | 41 ++++++++++---------------
> drivers/gpu/drm/radeon/atombios_crtc.c | 14 ++++-----
> drivers/gpu/drm/vmwgfx/vmwgfx_kms.c | 3 +-
> 17 files changed, 80 insertions(+), 86 deletions(-)
>
> diff --git a/include/drm/drm_fourcc.h b/include/drm/drm_fourcc.h
> index dc0aafa..4b03ca0 100644
> --- a/include/drm/drm_fourcc.h
> +++ b/include/drm/drm_fourcc.h
> @@ -45,6 +45,14 @@ struct drm_format_info {
> u8 vsub;
> };
>
> +/**
> + * struct drm_format_name_buf - name of a DRM format
> + * @str: string buffer containing the format name
> + */
> +struct drm_format_name_buf {
> + char str[32];
> +};
> +
> const struct drm_format_info *__drm_format_info(u32 format);
> const struct drm_format_info *drm_format_info(u32 format);
> uint32_t drm_mode_legacy_fb_format(uint32_t bpp, uint32_t depth);
> @@ -54,6 +62,6 @@ int drm_format_horz_chroma_subsampling(uint32_t format);
> int drm_format_vert_chroma_subsampling(uint32_t format);
> int drm_format_plane_width(int width, uint32_t format, int plane);
> int drm_format_plane_height(int height, uint32_t format, int plane);
> -char *drm_get_format_name(uint32_t format) __malloc;
> +char *drm_get_format_name(uint32_t format, struct drm_format_name_buf *buf);
>
> #endif /* __DRM_FOURCC_H__ */
> diff --git a/drivers/gpu/drm/drm_fourcc.c b/drivers/gpu/drm/drm_fourcc.c
> index cbb8b77..99b0b60 100644
> --- a/drivers/gpu/drm/drm_fourcc.c
> +++ b/drivers/gpu/drm/drm_fourcc.c
> @@ -79,17 +79,13 @@ uint32_t drm_mode_legacy_fb_format(uint32_t bpp, uint32_t depth)
> EXPORT_SYMBOL(drm_mode_legacy_fb_format);
>
> /**
> - * drm_get_format_name - return a string for drm fourcc format
> + * drm_get_format_name - fill a string with a drm fourcc format's name
> * @format: format to compute name of
> + * @buf: caller-supplied buffer
> - *
> - * Note that the buffer returned by this function is owned by the caller
> - * and will need to be freed using kfree().
> */
> -char *drm_get_format_name(uint32_t format)
> +char *drm_get_format_name(uint32_t format, struct drm_format_name_buf *buf)
> {
> - char *buf = kmalloc(32, GFP_KERNEL);
> -
> - snprintf(buf, 32,
> + snprintf(buf->str, sizeof(buf->str),
> "%c%c%c%c %s-endian (0x%08x)",
> printable_char(format & 0xff),
> printable_char((format >> 8) & 0xff),
> @@ -98,7 +94,7 @@ char *drm_get_format_name(uint32_t format)
> format & DRM_FORMAT_BIG_ENDIAN ? "big" : "little",
> format);
>
> - return buf;
> + return buf->str;
> }
> EXPORT_SYMBOL(drm_get_format_name);
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/dce_v10_0.c b/drivers/gpu/drm/amd/amdgpu/dce_v10_0.c
> index 199d3f7..2924cdd 100644
> --- a/drivers/gpu/drm/amd/amdgpu/dce_v10_0.c
> +++ b/drivers/gpu/drm/amd/amdgpu/dce_v10_0.c
> @@ -2032,7 +2032,7 @@ static int dce_v10_0_crtc_do_set_base(struct drm_crtc *crtc,
> u32 tmp, viewport_w, viewport_h;
> int r;
> bool bypass_lut = false;
> - char *format_name;
> + struct drm_format_name_buf format_name;
>
> /* no fb bound */
> if (!atomic && !crtc->primary->fb) {
> @@ -2144,9 +2144,8 @@ static int dce_v10_0_crtc_do_set_base(struct drm_crtc *crtc,
> bypass_lut = true;
> break;
> default:
> - format_name = drm_get_format_name(target_fb->pixel_format);
> - DRM_ERROR("Unsupported screen format %s\n", format_name);
> + DRM_ERROR("Unsupported screen format %s\n",
> + drm_get_format_name(target_fb->pixel_format, &format_name));
> - kfree(format_name);
> return -EINVAL;
> }
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/dce_v11_0.c b/drivers/gpu/drm/amd/amdgpu/dce_v11_0.c
> index ecd000e..f0e3c5c 100644
> --- a/drivers/gpu/drm/amd/amdgpu/dce_v11_0.c
> +++ b/drivers/gpu/drm/amd/amdgpu/dce_v11_0.c
> @@ -2013,7 +2013,7 @@ static int dce_v11_0_crtc_do_set_base(struct drm_crtc *crtc,
> u32 tmp, viewport_w, viewport_h;
> int r;
> bool bypass_lut = false;
> - char *format_name;
> + struct drm_format_name_buf format_name;
>
> /* no fb bound */
> if (!atomic && !crtc->primary->fb) {
> @@ -2125,9 +2125,8 @@ static int dce_v11_0_crtc_do_set_base(struct drm_crtc *crtc,
> bypass_lut = true;
> break;
> default:
> - format_name = drm_get_format_name(target_fb->pixel_format);
> - DRM_ERROR("Unsupported screen format %s\n", format_name);
> + DRM_ERROR("Unsupported screen format %s\n",
> + drm_get_format_name(target_fb->pixel_format, &format_name));
> - kfree(format_name);
> return -EINVAL;
> }
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/dce_v6_0.c b/drivers/gpu/drm/amd/amdgpu/dce_v6_0.c
> index 44547f9..5c6b82f 100644
> --- a/drivers/gpu/drm/amd/amdgpu/dce_v6_0.c
> +++ b/drivers/gpu/drm/amd/amdgpu/dce_v6_0.c
> @@ -1456,6 +1456,7 @@ static int dce_v6_0_crtc_do_set_base(struct drm_crtc *crtc,
> u32 viewport_w, viewport_h;
> int r;
> bool bypass_lut = false;
> + struct drm_format_name_buf format_name;
>
> /* no fb bound */
> if (!atomic && !crtc->primary->fb) {
> @@ -1559,7 +1560,7 @@ static int dce_v6_0_crtc_do_set_base(struct drm_crtc *crtc,
> break;
> default:
> DRM_ERROR("Unsupported screen format %s\n",
> - drm_get_format_name(target_fb->pixel_format));
> + drm_get_format_name(target_fb->pixel_format, &format_name));
> return -EINVAL;
> }
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/dce_v8_0.c b/drivers/gpu/drm/amd/amdgpu/dce_v8_0.c
> index 979aedf..5aef19d 100644
> --- a/drivers/gpu/drm/amd/amdgpu/dce_v8_0.c
> +++ b/drivers/gpu/drm/amd/amdgpu/dce_v8_0.c
> @@ -1910,7 +1910,7 @@ static int dce_v8_0_crtc_do_set_base(struct drm_crtc *crtc,
> u32 viewport_w, viewport_h;
> int r;
> bool bypass_lut = false;
> - char *format_name;
> + struct drm_format_name_buf format_name;
>
> /* no fb bound */
> if (!atomic && !crtc->primary->fb) {
> @@ -2015,9 +2015,8 @@ static int dce_v8_0_crtc_do_set_base(struct drm_crtc *crtc,
> bypass_lut = true;
> break;
> default:
> - format_name = drm_get_format_name(target_fb->pixel_format);
> - DRM_ERROR("Unsupported screen format %s\n", format_name);
> + DRM_ERROR("Unsupported screen format %s\n",
> + drm_get_format_name(target_fb->pixel_format, &format_name));
> - kfree(format_name);
> return -EINVAL;
> }
>
> diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c
> index c32fb3c..f29d3c5 100644
> --- a/drivers/gpu/drm/drm_atomic.c
> +++ b/drivers/gpu/drm/drm_atomic.c
> @@ -835,9 +835,10 @@ static int drm_atomic_plane_check(struct drm_plane *plane,
> /* Check whether this plane supports the fb pixel format. */
> ret = drm_plane_check_pixel_format(plane, state->fb->pixel_format);
> if (ret) {
> - char *format_name = drm_get_format_name(state->fb->pixel_format);
> - DRM_DEBUG_ATOMIC("Invalid pixel format %s\n", format_name);
> + struct drm_format_name_buf format_name;
> + DRM_DEBUG_ATOMIC("Invalid pixel format %s\n",
> + drm_get_format_name(state->fb->pixel_format,
> + &format_name));
> - kfree(format_name);
> return ret;
> }
>
> diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
> index 13441e2..08ac216 100644
> --- a/drivers/gpu/drm/drm_crtc.c
> +++ b/drivers/gpu/drm/drm_crtc.c
> @@ -827,9 +827,10 @@ int drm_mode_setcrtc(struct drm_device *dev, void *data,
> ret = drm_plane_check_pixel_format(crtc->primary,
> fb->pixel_format);
> if (ret) {
> - char *format_name = drm_get_format_name(fb->pixel_format);
> - DRM_DEBUG_KMS("Invalid pixel format %s\n", format_name);
> + struct drm_format_name_buf format_name;
> + DRM_DEBUG_KMS("Invalid pixel format %s\n",
> + drm_get_format_name(fb->pixel_format,
> + &format_name));
> - kfree(format_name);
> goto out;
> }
> }
> diff --git a/drivers/gpu/drm/drm_framebuffer.c b/drivers/gpu/drm/drm_framebuffer.c
> index 49fd7db..df6b180 100644
> --- a/drivers/gpu/drm/drm_framebuffer.c
> +++ b/drivers/gpu/drm/drm_framebuffer.c
> @@ -133,9 +133,10 @@ static int framebuffer_check(const struct drm_mode_fb_cmd2 *r)
>
> info = __drm_format_info(r->pixel_format & ~DRM_FORMAT_BIG_ENDIAN);
> if (!info) {
> - char *format_name = drm_get_format_name(r->pixel_format);
> - DRM_DEBUG_KMS("bad framebuffer format %s\n", format_name);
> + struct drm_format_name_buf format_name;
> + DRM_DEBUG_KMS("bad framebuffer format %s\n",
> + drm_get_format_name(r->pixel_format,
> + &format_name));
> - kfree(format_name);
> return -EINVAL;
> }
>
> diff --git a/drivers/gpu/drm/drm_modeset_helper.c b/drivers/gpu/drm/drm_modeset_helper.c
> index 2544dfe..2f452b3 100644
> --- a/drivers/gpu/drm/drm_modeset_helper.c
> +++ b/drivers/gpu/drm/drm_modeset_helper.c
> @@ -75,10 +75,11 @@ void drm_helper_mode_fill_fb_struct(struct drm_framebuffer *fb,
>
> info = drm_format_info(mode_cmd->pixel_format);
> if (!info || !info->depth) {
> - char *format_name = drm_get_format_name(mode_cmd->pixel_format);
> + struct drm_format_name_buf format_name;
>
> - DRM_DEBUG_KMS("non-RGB pixel format %s\n", format_name);
> + DRM_DEBUG_KMS("non-RGB pixel format %s\n",
> + drm_get_format_name(mode_cmd->pixel_format,
> + &format_name));
> - kfree(format_name);
>
> fb->depth = 0;
> fb->bits_per_pixel = 0;
> diff --git a/drivers/gpu/drm/drm_plane.c b/drivers/gpu/drm/drm_plane.c
> index 249c0ae..2ba0c22 100644
> --- a/drivers/gpu/drm/drm_plane.c
> +++ b/drivers/gpu/drm/drm_plane.c
> @@ -479,9 +479,10 @@ static int __setplane_internal(struct drm_plane *plane,
> /* Check whether this plane supports the fb pixel format. */
> ret = drm_plane_check_pixel_format(plane, fb->pixel_format);
> if (ret) {
> - char *format_name = drm_get_format_name(fb->pixel_format);
> - DRM_DEBUG_KMS("Invalid pixel format %s\n", format_name);
> + struct drm_format_name_buf format_name;
> + DRM_DEBUG_KMS("Invalid pixel format %s\n",
> + drm_get_format_name(fb->pixel_format,
> + &format_name));
> - kfree(format_name);
> goto out;
> }
>
> diff --git a/drivers/gpu/drm/hisilicon/kirin/kirin_drm_ade.c b/drivers/gpu/drm/hisilicon/kirin/kirin_drm_ade.c
> index 7e7a4d4..afc2b5d 100644
> --- a/drivers/gpu/drm/hisilicon/kirin/kirin_drm_ade.c
> +++ b/drivers/gpu/drm/hisilicon/kirin/kirin_drm_ade.c
> @@ -608,17 +608,16 @@ static void ade_rdma_set(void __iomem *base, struct drm_framebuffer *fb,
> u32 ch, u32 y, u32 in_h, u32 fmt)
> {
> struct drm_gem_cma_object *obj = drm_fb_cma_get_gem_obj(fb, 0);
> - char *format_name;
> + struct drm_format_name_buf format_name;
> u32 reg_ctrl, reg_addr, reg_size, reg_stride, reg_space, reg_en;
> u32 stride = fb->pitches[0];
> u32 addr = (u32)obj->paddr + y * stride;
>
> DRM_DEBUG_DRIVER("rdma%d: (y=%d, height=%d), stride=%d, paddr=0x%x\n",
> ch + 1, y, in_h, stride, (u32)obj->paddr);
> - format_name = drm_get_format_name(fb->pixel_format);
> DRM_DEBUG_DRIVER("addr=0x%x, fb:%dx%d, pixel_format=%d(%s)\n",
> - addr, fb->width, fb->height, fmt, format_name);
> + addr, fb->width, fb->height, fmt,
> + drm_get_format_name(fb->pixel_format, &format_name));
> - kfree(format_name);
>
> /* get reg offset */
> reg_ctrl = RD_CH_CTRL(ch);
> diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
> index 20638d2..670423e 100644
> --- a/drivers/gpu/drm/i915/i915_debugfs.c
> +++ b/drivers/gpu/drm/i915/i915_debugfs.c
> @@ -2971,7 +2971,7 @@ static void intel_plane_info(struct seq_file *m, struct intel_crtc *intel_crtc)
> for_each_intel_plane_on_crtc(dev, intel_crtc, intel_plane) {
> struct drm_plane_state *state;
> struct drm_plane *plane = &intel_plane->base;
> - char *format_name;
> + struct drm_format_name_buf format_name;
>
> if (!plane->state) {
> seq_puts(m, "plane->state is NULL!\n");
> @@ -2981,9 +2981,9 @@ static void intel_plane_info(struct seq_file *m, struct intel_crtc *intel_crtc)
> state = plane->state;
>
> if (state->fb) {
> - format_name = drm_get_format_name(state->fb->pixel_format);
> + drm_get_format_name(state->fb->pixel_format, &format_name);
> } else {
> - format_name = kstrdup("N/A", GFP_KERNEL);
> + sprintf(format_name.str, "N/A");
> }
>
> seq_printf(m, "\t--Plane id %d: type=%s, crtc_pos=%4dx%4d, crtc_size=%4dx%4d, src_pos=%d.%04ux%d.%04u, src_size=%d.%04ux%d.%04u, format=%s, rotation=%s\n",
> @@ -2999,10 +2999,8 @@ static void intel_plane_info(struct seq_file *m, struct intel_crtc *intel_crtc)
> ((state->src_w & 0xffff) * 15625) >> 10,
> (state->src_h >> 16),
> ((state->src_h & 0xffff) * 15625) >> 10,
> - format_name,
> + format_name.str,
> plane_rotation(state->rotation));
> -
> - kfree(format_name);
> }
> }
>
> diff --git a/drivers/gpu/drm/i915/intel_atomic_plane.c b/drivers/gpu/drm/i915/intel_atomic_plane.c
> index c762ae5..6c76e3d 100644
> --- a/drivers/gpu/drm/i915/intel_atomic_plane.c
> +++ b/drivers/gpu/drm/i915/intel_atomic_plane.c
> @@ -143,7 +143,7 @@ static int intel_plane_atomic_check(struct drm_plane *plane,
> crtc_state->base.enable ? crtc_state->pipe_src_h : 0;
>
> if (state->fb && drm_rotation_90_or_270(state->rotation)) {
> - char *format_name;
> + struct drm_format_name_buf format_name;
>
> if (!(state->fb->modifier[0] == I915_FORMAT_MOD_Y_TILED ||
> state->fb->modifier[0] == I915_FORMAT_MOD_Yf_TILED)) {
> @@ -159,9 +159,9 @@ static int intel_plane_atomic_check(struct drm_plane *plane,
> switch (state->fb->pixel_format) {
> case DRM_FORMAT_C8:
> case DRM_FORMAT_RGB565:
> - format_name = drm_get_format_name(state->fb->pixel_format);
> - DRM_DEBUG_KMS("Unsupported pixel format %s for 90/270!\n", format_name);
> + DRM_DEBUG_KMS("Unsupported pixel format %s for 90/270!\n",
> + drm_get_format_name(state->fb->pixel_format,
> + &format_name));
> - kfree(format_name);
> return -EINVAL;
>
> default:
> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> index 6f8f6ec..8209170 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -12871,7 +12871,7 @@ static void intel_dump_pipe_config(struct intel_crtc *crtc,
>
> DRM_DEBUG_KMS("planes on this crtc\n");
> list_for_each_entry(plane, &dev->mode_config.plane_list, head) {
> - char *format_name;
> + struct drm_format_name_buf format_name;
> intel_plane = to_intel_plane(plane);
> if (intel_plane->pipe != crtc->pipe)
> continue;
> @@ -12884,12 +12884,11 @@ static void intel_dump_pipe_config(struct intel_crtc *crtc,
> continue;
> }
>
> - format_name = drm_get_format_name(fb->pixel_format);
> -
> DRM_DEBUG_KMS("[PLANE:%d:%s] enabled",
> plane->base.id, plane->name);
> DRM_DEBUG_KMS("\tFB:%d, fb = %ux%u format = %s",
> - fb->base.id, fb->width, fb->height, format_name);
> + fb->base.id, fb->width, fb->height,
> + drm_get_format_name(fb->pixel_format, &format_name));
> DRM_DEBUG_KMS("\tscaler:%d src %dx%d+%d+%d dst %dx%d+%d+%d\n",
> state->scaler_id,
> state->base.src.x1 >> 16,
> @@ -12899,8 +12898,6 @@ static void intel_dump_pipe_config(struct intel_crtc *crtc,
> state->base.dst.x1, state->base.dst.y1,
> drm_rect_width(&state->base.dst),
> drm_rect_height(&state->base.dst));
> -
> - kfree(format_name);
> }
> }
>
> @@ -15749,7 +15746,7 @@ static int intel_framebuffer_init(struct drm_device *dev,
> unsigned int tiling = i915_gem_object_get_tiling(obj);
> int ret;
> u32 pitch_limit, stride_alignment;
> - char *format_name;
> + struct drm_format_name_buf format_name;
>
> WARN_ON(!mutex_is_locked(&dev->struct_mutex));
>
> @@ -15840,18 +15837,16 @@ static int intel_framebuffer_init(struct drm_device *dev,
> break;
> case DRM_FORMAT_XRGB1555:
> if (INTEL_INFO(dev)->gen > 3) {
> - format_name = drm_get_format_name(mode_cmd->pixel_format);
> - DRM_DEBUG("unsupported pixel format: %s\n", format_name);
> + DRM_DEBUG("unsupported pixel format: %s\n",
> + drm_get_format_name(mode_cmd->pixel_format, &format_name));
> - kfree(format_name);
> return -EINVAL;
> }
> break;
> case DRM_FORMAT_ABGR8888:
> if (!IS_VALLEYVIEW(dev_priv) && !IS_CHERRYVIEW(dev_priv) &&
> INTEL_INFO(dev)->gen < 9) {
> - format_name = drm_get_format_name(mode_cmd->pixel_format);
> - DRM_DEBUG("unsupported pixel format: %s\n", format_name);
> + DRM_DEBUG("unsupported pixel format: %s\n",
> + drm_get_format_name(mode_cmd->pixel_format, &format_name));
> - kfree(format_name);
> return -EINVAL;
> }
> break;
> @@ -15859,17 +15854,15 @@ static int intel_framebuffer_init(struct drm_device *dev,
> case DRM_FORMAT_XRGB2101010:
> case DRM_FORMAT_XBGR2101010:
> if (INTEL_INFO(dev)->gen < 4) {
> - format_name = drm_get_format_name(mode_cmd->pixel_format);
> - DRM_DEBUG("unsupported pixel format: %s\n", format_name);
> + DRM_DEBUG("unsupported pixel format: %s\n",
> + drm_get_format_name(mode_cmd->pixel_format, &format_name));
> - kfree(format_name);
> return -EINVAL;
> }
> break;
> case DRM_FORMAT_ABGR2101010:
> if (!IS_VALLEYVIEW(dev_priv) && !IS_CHERRYVIEW(dev_priv)) {
> - format_name = drm_get_format_name(mode_cmd->pixel_format);
> - DRM_DEBUG("unsupported pixel format: %s\n", format_name);
> + DRM_DEBUG("unsupported pixel format: %s\n",
> + drm_get_format_name(mode_cmd->pixel_format, &format_name));
> - kfree(format_name);
> return -EINVAL;
> }
> break;
> @@ -15878,16 +15871,14 @@ static int intel_framebuffer_init(struct drm_device *dev,
> case DRM_FORMAT_YVYU:
> case DRM_FORMAT_VYUY:
> if (INTEL_INFO(dev)->gen < 5) {
> - format_name = drm_get_format_name(mode_cmd->pixel_format);
> - DRM_DEBUG("unsupported pixel format: %s\n", format_name);
> + DRM_DEBUG("unsupported pixel format: %s\n",
> + drm_get_format_name(mode_cmd->pixel_format, &format_name));
> - kfree(format_name);
> return -EINVAL;
> }
> break;
> default:
> - format_name = drm_get_format_name(mode_cmd->pixel_format);
> - DRM_DEBUG("unsupported pixel format: %s\n", format_name);
> + DRM_DEBUG("unsupported pixel format: %s\n",
> + drm_get_format_name(mode_cmd->pixel_format, &format_name));
> - kfree(format_name);
> return -EINVAL;
> }
>
> diff --git a/drivers/gpu/drm/radeon/atombios_crtc.c b/drivers/gpu/drm/radeon/atombios_crtc.c
> index 74f99ba..05f4ebe 100644
> --- a/drivers/gpu/drm/radeon/atombios_crtc.c
> +++ b/drivers/gpu/drm/radeon/atombios_crtc.c
> @@ -1156,7 +1156,7 @@ static int dce4_crtc_do_set_base(struct drm_crtc *crtc,
> u32 tmp, viewport_w, viewport_h;
> int r;
> bool bypass_lut = false;
> - char *format_name;
> + struct drm_format_name_buf format_name;
>
> /* no fb bound */
> if (!atomic && !crtc->primary->fb) {
> @@ -1260,9 +1260,8 @@ static int dce4_crtc_do_set_base(struct drm_crtc *crtc,
> bypass_lut = true;
> break;
> default:
> - format_name = drm_get_format_name(target_fb->pixel_format);
> - DRM_ERROR("Unsupported screen format %s\n", format_name);
> + DRM_ERROR("Unsupported screen format %s\n",
> + drm_get_format_name(target_fb->pixel_format, &format_name));
> - kfree(format_name);
> return -EINVAL;
> }
>
> @@ -1473,7 +1472,7 @@ static int avivo_crtc_do_set_base(struct drm_crtc *crtc,
> u32 viewport_w, viewport_h;
> int r;
> bool bypass_lut = false;
> - char *format_name;
> + struct drm_format_name_buf format_name;
>
> /* no fb bound */
> if (!atomic && !crtc->primary->fb) {
> @@ -1563,9 +1562,8 @@ static int avivo_crtc_do_set_base(struct drm_crtc *crtc,
> bypass_lut = true;
> break;
> default:
> - format_name = drm_get_format_name(target_fb->pixel_format);
> - DRM_ERROR("Unsupported screen format %s\n", format_name);
> + DRM_ERROR("Unsupported screen format %s\n",
> + drm_get_format_name(target_fb->pixel_format, &format_name));
> - kfree(format_name);
> return -EINVAL;
> }
>
> diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c b/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c
> index c965514..e3f68cc 100644
> --- a/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c
> +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c
> @@ -985,8 +985,9 @@ static struct drm_framebuffer *vmw_kms_fb_create(struct drm_device *dev,
>
> info = drm_format_info(mode_cmd2->pixel_format);
> if (!info || !info->depth) {
> + struct drm_format_name_buf format_name;
> DRM_ERROR("Unsupported framebuffer format %s\n",
> - drm_get_format_name(mode_cmd2->pixel_format));
> + drm_get_format_name(mode_cmd2->pixel_format, &format_name));
> return ERR_PTR(-EINVAL);
> }
>

2016-11-07 08:10:53

[permalink] [raw]

Subject: Re: [PATCH v2] drm: move allocation out of drm_get_format_name()

On Mon, 07 Nov 2016, Eric Engestrom <[email protected]> wrote:
> Fixes: 90844f00049e9f42573fd31d7c32e8fd31d3fd07
>
> drm: make drm_get_format_name thread-safe
>
> Signed-off-by: Eric Engestrom <[email protected]>
> [danvet: Clarify that the returned pointer must be freed with
> kfree().]
> Signed-off-by: Daniel Vetter <[email protected]>

The Fixes: format is:

Fixes: 90844f00049e ("drm: make drm_get_format_name thread-safe")

But is this a fix, really, or just an improvement? What exactly is the
bug being fixed? The commit message is not sufficient.

> Cc: Rob Clark <[email protected]>
> Cc: Christian König <[email protected]>
> Suggested-by: Ville Syrjälä <[email protected]>
> Signed-off-by: Eric Engestrom <[email protected]>
> ---
>
> v2: use single-field struct instead of typedef to let the compiler
> enforce the type (Christian König)

Just to make it clear: NAK three times over for v1. This patch is
definitely a better alternative.

>
> ---
> include/drm/drm_fourcc.h | 10 +++++-
> drivers/gpu/drm/drm_fourcc.c | 14 +++------
> drivers/gpu/drm/amd/amdgpu/dce_v10_0.c | 7 ++---
> drivers/gpu/drm/amd/amdgpu/dce_v11_0.c | 7 ++---
> drivers/gpu/drm/amd/amdgpu/dce_v6_0.c | 3 +-
> drivers/gpu/drm/amd/amdgpu/dce_v8_0.c | 7 ++---
> drivers/gpu/drm/drm_atomic.c | 7 +++--
> drivers/gpu/drm/drm_crtc.c | 7 +++--
> drivers/gpu/drm/drm_framebuffer.c | 7 +++--
> drivers/gpu/drm/drm_modeset_helper.c | 7 +++--
> drivers/gpu/drm/drm_plane.c | 7 +++--
> drivers/gpu/drm/hisilicon/kirin/kirin_drm_ade.c | 7 ++---
> drivers/gpu/drm/i915/i915_debugfs.c | 10 +++---
> drivers/gpu/drm/i915/intel_atomic_plane.c | 8 ++---
> drivers/gpu/drm/i915/intel_display.c | 41 ++++++++++---------------
> drivers/gpu/drm/radeon/atombios_crtc.c | 14 ++++-----
> drivers/gpu/drm/vmwgfx/vmwgfx_kms.c | 3 +-
> 17 files changed, 80 insertions(+), 86 deletions(-)
>
> diff --git a/include/drm/drm_fourcc.h b/include/drm/drm_fourcc.h
> index dc0aafa..4b03ca0 100644
> --- a/include/drm/drm_fourcc.h
> +++ b/include/drm/drm_fourcc.h
> @@ -45,6 +45,14 @@ struct drm_format_info {
> u8 vsub;
> };
>
> +/**
> + * struct drm_format_name_buf - name of a DRM format
> + * @str: string buffer containing the format name
> + */
> +struct drm_format_name_buf {
> + char str[32];
> +};
> +
> const struct drm_format_info *__drm_format_info(u32 format);
> const struct drm_format_info *drm_format_info(u32 format);
> uint32_t drm_mode_legacy_fb_format(uint32_t bpp, uint32_t depth);
> @@ -54,6 +62,6 @@ int drm_format_horz_chroma_subsampling(uint32_t format);
> int drm_format_vert_chroma_subsampling(uint32_t format);
> int drm_format_plane_width(int width, uint32_t format, int plane);
> int drm_format_plane_height(int height, uint32_t format, int plane);
> -char *drm_get_format_name(uint32_t format) __malloc;
> +char *drm_get_format_name(uint32_t format, struct drm_format_name_buf *buf);

I wonder if it would be better to make that return "const char *". If
the user really wants to look under the hood, there's buf->str. *shrug*

With the commit message improved,

Reviewed-by: Jani Nikula <[email protected]>

>
> #endif /* __DRM_FOURCC_H__ */
> diff --git a/drivers/gpu/drm/drm_fourcc.c b/drivers/gpu/drm/drm_fourcc.c
> index cbb8b77..99b0b60 100644
> --- a/drivers/gpu/drm/drm_fourcc.c
> +++ b/drivers/gpu/drm/drm_fourcc.c
> @@ -79,17 +79,13 @@ uint32_t drm_mode_legacy_fb_format(uint32_t bpp, uint32_t depth)
> EXPORT_SYMBOL(drm_mode_legacy_fb_format);
>
> /**
> - * drm_get_format_name - return a string for drm fourcc format
> + * drm_get_format_name - fill a string with a drm fourcc format's name
> * @format: format to compute name of
> + * @buf: caller-supplied buffer
> - *
> - * Note that the buffer returned by this function is owned by the caller
> - * and will need to be freed using kfree().
> */
> -char *drm_get_format_name(uint32_t format)
> +char *drm_get_format_name(uint32_t format, struct drm_format_name_buf *buf)
> {
> - char *buf = kmalloc(32, GFP_KERNEL);
> -
> - snprintf(buf, 32,
> + snprintf(buf->str, sizeof(buf->str),
> "%c%c%c%c %s-endian (0x%08x)",
> printable_char(format & 0xff),
> printable_char((format >> 8) & 0xff),
> @@ -98,7 +94,7 @@ char *drm_get_format_name(uint32_t format)
> format & DRM_FORMAT_BIG_ENDIAN ? "big" : "little",
> format);
>
> - return buf;
> + return buf->str;
> }
> EXPORT_SYMBOL(drm_get_format_name);
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/dce_v10_0.c b/drivers/gpu/drm/amd/amdgpu/dce_v10_0.c
> index 199d3f7..2924cdd 100644
> --- a/drivers/gpu/drm/amd/amdgpu/dce_v10_0.c
> +++ b/drivers/gpu/drm/amd/amdgpu/dce_v10_0.c
> @@ -2032,7 +2032,7 @@ static int dce_v10_0_crtc_do_set_base(struct drm_crtc *crtc,
> u32 tmp, viewport_w, viewport_h;
> int r;
> bool bypass_lut = false;
> - char *format_name;
> + struct drm_format_name_buf format_name;
>
> /* no fb bound */
> if (!atomic && !crtc->primary->fb) {
> @@ -2144,9 +2144,8 @@ static int dce_v10_0_crtc_do_set_base(struct drm_crtc *crtc,
> bypass_lut = true;
> break;
> default:
> - format_name = drm_get_format_name(target_fb->pixel_format);
> - DRM_ERROR("Unsupported screen format %s\n", format_name);
> + DRM_ERROR("Unsupported screen format %s\n",
> + drm_get_format_name(target_fb->pixel_format, &format_name));
> - kfree(format_name);
> return -EINVAL;
> }
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/dce_v11_0.c b/drivers/gpu/drm/amd/amdgpu/dce_v11_0.c
> index ecd000e..f0e3c5c 100644
> --- a/drivers/gpu/drm/amd/amdgpu/dce_v11_0.c
> +++ b/drivers/gpu/drm/amd/amdgpu/dce_v11_0.c
> @@ -2013,7 +2013,7 @@ static int dce_v11_0_crtc_do_set_base(struct drm_crtc *crtc,
> u32 tmp, viewport_w, viewport_h;
> int r;
> bool bypass_lut = false;
> - char *format_name;
> + struct drm_format_name_buf format_name;
>
> /* no fb bound */
> if (!atomic && !crtc->primary->fb) {
> @@ -2125,9 +2125,8 @@ static int dce_v11_0_crtc_do_set_base(struct drm_crtc *crtc,
> bypass_lut = true;
> break;
> default:
> - format_name = drm_get_format_name(target_fb->pixel_format);
> - DRM_ERROR("Unsupported screen format %s\n", format_name);
> + DRM_ERROR("Unsupported screen format %s\n",
> + drm_get_format_name(target_fb->pixel_format, &format_name));
> - kfree(format_name);
> return -EINVAL;
> }
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/dce_v6_0.c b/drivers/gpu/drm/amd/amdgpu/dce_v6_0.c
> index 44547f9..5c6b82f 100644
> --- a/drivers/gpu/drm/amd/amdgpu/dce_v6_0.c
> +++ b/drivers/gpu/drm/amd/amdgpu/dce_v6_0.c
> @@ -1456,6 +1456,7 @@ static int dce_v6_0_crtc_do_set_base(struct drm_crtc *crtc,
> u32 viewport_w, viewport_h;
> int r;
> bool bypass_lut = false;
> + struct drm_format_name_buf format_name;
>
> /* no fb bound */
> if (!atomic && !crtc->primary->fb) {
> @@ -1559,7 +1560,7 @@ static int dce_v6_0_crtc_do_set_base(struct drm_crtc *crtc,
> break;
> default:
> DRM_ERROR("Unsupported screen format %s\n",
> - drm_get_format_name(target_fb->pixel_format));
> + drm_get_format_name(target_fb->pixel_format, &format_name));
> return -EINVAL;
> }
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/dce_v8_0.c b/drivers/gpu/drm/amd/amdgpu/dce_v8_0.c
> index 979aedf..5aef19d 100644
> --- a/drivers/gpu/drm/amd/amdgpu/dce_v8_0.c
> +++ b/drivers/gpu/drm/amd/amdgpu/dce_v8_0.c
> @@ -1910,7 +1910,7 @@ static int dce_v8_0_crtc_do_set_base(struct drm_crtc *crtc,
> u32 viewport_w, viewport_h;
> int r;
> bool bypass_lut = false;
> - char *format_name;
> + struct drm_format_name_buf format_name;
>
> /* no fb bound */
> if (!atomic && !crtc->primary->fb) {
> @@ -2015,9 +2015,8 @@ static int dce_v8_0_crtc_do_set_base(struct drm_crtc *crtc,
> bypass_lut = true;
> break;
> default:
> - format_name = drm_get_format_name(target_fb->pixel_format);
> - DRM_ERROR("Unsupported screen format %s\n", format_name);
> + DRM_ERROR("Unsupported screen format %s\n",
> + drm_get_format_name(target_fb->pixel_format, &format_name));
> - kfree(format_name);
> return -EINVAL;
> }
>
> diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c
> index c32fb3c..f29d3c5 100644
> --- a/drivers/gpu/drm/drm_atomic.c
> +++ b/drivers/gpu/drm/drm_atomic.c
> @@ -835,9 +835,10 @@ static int drm_atomic_plane_check(struct drm_plane *plane,
> /* Check whether this plane supports the fb pixel format. */
> ret = drm_plane_check_pixel_format(plane, state->fb->pixel_format);
> if (ret) {
> - char *format_name = drm_get_format_name(state->fb->pixel_format);
> - DRM_DEBUG_ATOMIC("Invalid pixel format %s\n", format_name);
> + struct drm_format_name_buf format_name;
> + DRM_DEBUG_ATOMIC("Invalid pixel format %s\n",
> + drm_get_format_name(state->fb->pixel_format,
> + &format_name));
> - kfree(format_name);
> return ret;
> }
>
> diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
> index 13441e2..08ac216 100644
> --- a/drivers/gpu/drm/drm_crtc.c
> +++ b/drivers/gpu/drm/drm_crtc.c
> @@ -827,9 +827,10 @@ int drm_mode_setcrtc(struct drm_device *dev, void *data,
> ret = drm_plane_check_pixel_format(crtc->primary,
> fb->pixel_format);
> if (ret) {
> - char *format_name = drm_get_format_name(fb->pixel_format);
> - DRM_DEBUG_KMS("Invalid pixel format %s\n", format_name);
> + struct drm_format_name_buf format_name;
> + DRM_DEBUG_KMS("Invalid pixel format %s\n",
> + drm_get_format_name(fb->pixel_format,
> + &format_name));
> - kfree(format_name);
> goto out;
> }
> }
> diff --git a/drivers/gpu/drm/drm_framebuffer.c b/drivers/gpu/drm/drm_framebuffer.c
> index 49fd7db..df6b180 100644
> --- a/drivers/gpu/drm/drm_framebuffer.c
> +++ b/drivers/gpu/drm/drm_framebuffer.c
> @@ -133,9 +133,10 @@ static int framebuffer_check(const struct drm_mode_fb_cmd2 *r)
>
> info = __drm_format_info(r->pixel_format & ~DRM_FORMAT_BIG_ENDIAN);
> if (!info) {
> - char *format_name = drm_get_format_name(r->pixel_format);
> - DRM_DEBUG_KMS("bad framebuffer format %s\n", format_name);
> + struct drm_format_name_buf format_name;
> + DRM_DEBUG_KMS("bad framebuffer format %s\n",
> + drm_get_format_name(r->pixel_format,
> + &format_name));
> - kfree(format_name);
> return -EINVAL;
> }
>
> diff --git a/drivers/gpu/drm/drm_modeset_helper.c b/drivers/gpu/drm/drm_modeset_helper.c
> index 2544dfe..2f452b3 100644
> --- a/drivers/gpu/drm/drm_modeset_helper.c
> +++ b/drivers/gpu/drm/drm_modeset_helper.c
> @@ -75,10 +75,11 @@ void drm_helper_mode_fill_fb_struct(struct drm_framebuffer *fb,
>
> info = drm_format_info(mode_cmd->pixel_format);
> if (!info || !info->depth) {
> - char *format_name = drm_get_format_name(mode_cmd->pixel_format);
> + struct drm_format_name_buf format_name;
>
> - DRM_DEBUG_KMS("non-RGB pixel format %s\n", format_name);
> + DRM_DEBUG_KMS("non-RGB pixel format %s\n",
> + drm_get_format_name(mode_cmd->pixel_format,
> + &format_name));
> - kfree(format_name);
>
> fb->depth = 0;
> fb->bits_per_pixel = 0;
> diff --git a/drivers/gpu/drm/drm_plane.c b/drivers/gpu/drm/drm_plane.c
> index 249c0ae..2ba0c22 100644
> --- a/drivers/gpu/drm/drm_plane.c
> +++ b/drivers/gpu/drm/drm_plane.c
> @@ -479,9 +479,10 @@ static int __setplane_internal(struct drm_plane *plane,
> /* Check whether this plane supports the fb pixel format. */
> ret = drm_plane_check_pixel_format(plane, fb->pixel_format);
> if (ret) {
> - char *format_name = drm_get_format_name(fb->pixel_format);
> - DRM_DEBUG_KMS("Invalid pixel format %s\n", format_name);
> + struct drm_format_name_buf format_name;
> + DRM_DEBUG_KMS("Invalid pixel format %s\n",
> + drm_get_format_name(fb->pixel_format,
> + &format_name));
> - kfree(format_name);
> goto out;
> }
>
> diff --git a/drivers/gpu/drm/hisilicon/kirin/kirin_drm_ade.c b/drivers/gpu/drm/hisilicon/kirin/kirin_drm_ade.c
> index 7e7a4d4..afc2b5d 100644
> --- a/drivers/gpu/drm/hisilicon/kirin/kirin_drm_ade.c
> +++ b/drivers/gpu/drm/hisilicon/kirin/kirin_drm_ade.c
> @@ -608,17 +608,16 @@ static void ade_rdma_set(void __iomem *base, struct drm_framebuffer *fb,
> u32 ch, u32 y, u32 in_h, u32 fmt)
> {
> struct drm_gem_cma_object *obj = drm_fb_cma_get_gem_obj(fb, 0);
> - char *format_name;
> + struct drm_format_name_buf format_name;
> u32 reg_ctrl, reg_addr, reg_size, reg_stride, reg_space, reg_en;
> u32 stride = fb->pitches[0];
> u32 addr = (u32)obj->paddr + y * stride;
>
> DRM_DEBUG_DRIVER("rdma%d: (y=%d, height=%d), stride=%d, paddr=0x%x\n",
> ch + 1, y, in_h, stride, (u32)obj->paddr);
> - format_name = drm_get_format_name(fb->pixel_format);
> DRM_DEBUG_DRIVER("addr=0x%x, fb:%dx%d, pixel_format=%d(%s)\n",
> - addr, fb->width, fb->height, fmt, format_name);
> + addr, fb->width, fb->height, fmt,
> + drm_get_format_name(fb->pixel_format, &format_name));
> - kfree(format_name);
>
> /* get reg offset */
> reg_ctrl = RD_CH_CTRL(ch);
> diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
> index 20638d2..670423e 100644
> --- a/drivers/gpu/drm/i915/i915_debugfs.c
> +++ b/drivers/gpu/drm/i915/i915_debugfs.c
> @@ -2971,7 +2971,7 @@ static void intel_plane_info(struct seq_file *m, struct intel_crtc *intel_crtc)
> for_each_intel_plane_on_crtc(dev, intel_crtc, intel_plane) {
> struct drm_plane_state *state;
> struct drm_plane *plane = &intel_plane->base;
> - char *format_name;
> + struct drm_format_name_buf format_name;
>
> if (!plane->state) {
> seq_puts(m, "plane->state is NULL!\n");
> @@ -2981,9 +2981,9 @@ static void intel_plane_info(struct seq_file *m, struct intel_crtc *intel_crtc)
> state = plane->state;
>
> if (state->fb) {
> - format_name = drm_get_format_name(state->fb->pixel_format);
> + drm_get_format_name(state->fb->pixel_format, &format_name);
> } else {
> - format_name = kstrdup("N/A", GFP_KERNEL);
> + sprintf(format_name.str, "N/A");
> }
>
> seq_printf(m, "\t--Plane id %d: type=%s, crtc_pos=%4dx%4d, crtc_size=%4dx%4d, src_pos=%d.%04ux%d.%04u, src_size=%d.%04ux%d.%04u, format=%s, rotation=%s\n",
> @@ -2999,10 +2999,8 @@ static void intel_plane_info(struct seq_file *m, struct intel_crtc *intel_crtc)
> ((state->src_w & 0xffff) * 15625) >> 10,
> (state->src_h >> 16),
> ((state->src_h & 0xffff) * 15625) >> 10,
> - format_name,
> + format_name.str,
> plane_rotation(state->rotation));
> -
> - kfree(format_name);
> }
> }
>
> diff --git a/drivers/gpu/drm/i915/intel_atomic_plane.c b/drivers/gpu/drm/i915/intel_atomic_plane.c
> index c762ae5..6c76e3d 100644
> --- a/drivers/gpu/drm/i915/intel_atomic_plane.c
> +++ b/drivers/gpu/drm/i915/intel_atomic_plane.c
> @@ -143,7 +143,7 @@ static int intel_plane_atomic_check(struct drm_plane *plane,
> crtc_state->base.enable ? crtc_state->pipe_src_h : 0;
>
> if (state->fb && drm_rotation_90_or_270(state->rotation)) {
> - char *format_name;
> + struct drm_format_name_buf format_name;
>
> if (!(state->fb->modifier[0] == I915_FORMAT_MOD_Y_TILED ||
> state->fb->modifier[0] == I915_FORMAT_MOD_Yf_TILED)) {
> @@ -159,9 +159,9 @@ static int intel_plane_atomic_check(struct drm_plane *plane,
> switch (state->fb->pixel_format) {
> case DRM_FORMAT_C8:
> case DRM_FORMAT_RGB565:
> - format_name = drm_get_format_name(state->fb->pixel_format);
> - DRM_DEBUG_KMS("Unsupported pixel format %s for 90/270!\n", format_name);
> + DRM_DEBUG_KMS("Unsupported pixel format %s for 90/270!\n",
> + drm_get_format_name(state->fb->pixel_format,
> + &format_name));
> - kfree(format_name);
> return -EINVAL;
>
> default:
> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> index 6f8f6ec..8209170 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -12871,7 +12871,7 @@ static void intel_dump_pipe_config(struct intel_crtc *crtc,
>
> DRM_DEBUG_KMS("planes on this crtc\n");
> list_for_each_entry(plane, &dev->mode_config.plane_list, head) {
> - char *format_name;
> + struct drm_format_name_buf format_name;
> intel_plane = to_intel_plane(plane);
> if (intel_plane->pipe != crtc->pipe)
> continue;
> @@ -12884,12 +12884,11 @@ static void intel_dump_pipe_config(struct intel_crtc *crtc,
> continue;
> }
>
> - format_name = drm_get_format_name(fb->pixel_format);
> -
> DRM_DEBUG_KMS("[PLANE:%d:%s] enabled",
> plane->base.id, plane->name);
> DRM_DEBUG_KMS("\tFB:%d, fb = %ux%u format = %s",
> - fb->base.id, fb->width, fb->height, format_name);
> + fb->base.id, fb->width, fb->height,
> + drm_get_format_name(fb->pixel_format, &format_name));
> DRM_DEBUG_KMS("\tscaler:%d src %dx%d+%d+%d dst %dx%d+%d+%d\n",
> state->scaler_id,
> state->base.src.x1 >> 16,
> @@ -12899,8 +12898,6 @@ static void intel_dump_pipe_config(struct intel_crtc *crtc,
> state->base.dst.x1, state->base.dst.y1,
> drm_rect_width(&state->base.dst),
> drm_rect_height(&state->base.dst));
> -
> - kfree(format_name);
> }
> }
>
> @@ -15749,7 +15746,7 @@ static int intel_framebuffer_init(struct drm_device *dev,
> unsigned int tiling = i915_gem_object_get_tiling(obj);
> int ret;
> u32 pitch_limit, stride_alignment;
> - char *format_name;
> + struct drm_format_name_buf format_name;
>
> WARN_ON(!mutex_is_locked(&dev->struct_mutex));
>
> @@ -15840,18 +15837,16 @@ static int intel_framebuffer_init(struct drm_device *dev,
> break;
> case DRM_FORMAT_XRGB1555:
> if (INTEL_INFO(dev)->gen > 3) {
> - format_name = drm_get_format_name(mode_cmd->pixel_format);
> - DRM_DEBUG("unsupported pixel format: %s\n", format_name);
> + DRM_DEBUG("unsupported pixel format: %s\n",
> + drm_get_format_name(mode_cmd->pixel_format, &format_name));
> - kfree(format_name);
> return -EINVAL;
> }
> break;
> case DRM_FORMAT_ABGR8888:
> if (!IS_VALLEYVIEW(dev_priv) && !IS_CHERRYVIEW(dev_priv) &&
> INTEL_INFO(dev)->gen < 9) {
> - format_name = drm_get_format_name(mode_cmd->pixel_format);
> - DRM_DEBUG("unsupported pixel format: %s\n", format_name);
> + DRM_DEBUG("unsupported pixel format: %s\n",
> + drm_get_format_name(mode_cmd->pixel_format, &format_name));
> - kfree(format_name);
> return -EINVAL;
> }
> break;
> @@ -15859,17 +15854,15 @@ static int intel_framebuffer_init(struct drm_device *dev,
> case DRM_FORMAT_XRGB2101010:
> case DRM_FORMAT_XBGR2101010:
> if (INTEL_INFO(dev)->gen < 4) {
> - format_name = drm_get_format_name(mode_cmd->pixel_format);
> - DRM_DEBUG("unsupported pixel format: %s\n", format_name);
> + DRM_DEBUG("unsupported pixel format: %s\n",
> + drm_get_format_name(mode_cmd->pixel_format, &format_name));
> - kfree(format_name);
> return -EINVAL;
> }
> break;
> case DRM_FORMAT_ABGR2101010:
> if (!IS_VALLEYVIEW(dev_priv) && !IS_CHERRYVIEW(dev_priv)) {
> - format_name = drm_get_format_name(mode_cmd->pixel_format);
> - DRM_DEBUG("unsupported pixel format: %s\n", format_name);
> + DRM_DEBUG("unsupported pixel format: %s\n",
> + drm_get_format_name(mode_cmd->pixel_format, &format_name));
> - kfree(format_name);
> return -EINVAL;
> }
> break;
> @@ -15878,16 +15871,14 @@ static int intel_framebuffer_init(struct drm_device *dev,
> case DRM_FORMAT_YVYU:
> case DRM_FORMAT_VYUY:
> if (INTEL_INFO(dev)->gen < 5) {
> - format_name = drm_get_format_name(mode_cmd->pixel_format);
> - DRM_DEBUG("unsupported pixel format: %s\n", format_name);
> + DRM_DEBUG("unsupported pixel format: %s\n",
> + drm_get_format_name(mode_cmd->pixel_format, &format_name));
> - kfree(format_name);
> return -EINVAL;
> }
> break;
> default:
> - format_name = drm_get_format_name(mode_cmd->pixel_format);
> - DRM_DEBUG("unsupported pixel format: %s\n", format_name);
> + DRM_DEBUG("unsupported pixel format: %s\n",
> + drm_get_format_name(mode_cmd->pixel_format, &format_name));
> - kfree(format_name);
> return -EINVAL;
> }
>
> diff --git a/drivers/gpu/drm/radeon/atombios_crtc.c b/drivers/gpu/drm/radeon/atombios_crtc.c
> index 74f99ba..05f4ebe 100644
> --- a/drivers/gpu/drm/radeon/atombios_crtc.c
> +++ b/drivers/gpu/drm/radeon/atombios_crtc.c
> @@ -1156,7 +1156,7 @@ static int dce4_crtc_do_set_base(struct drm_crtc *crtc,
> u32 tmp, viewport_w, viewport_h;
> int r;
> bool bypass_lut = false;
> - char *format_name;
> + struct drm_format_name_buf format_name;
>
> /* no fb bound */
> if (!atomic && !crtc->primary->fb) {
> @@ -1260,9 +1260,8 @@ static int dce4_crtc_do_set_base(struct drm_crtc *crtc,
> bypass_lut = true;
> break;
> default:
> - format_name = drm_get_format_name(target_fb->pixel_format);
> - DRM_ERROR("Unsupported screen format %s\n", format_name);
> + DRM_ERROR("Unsupported screen format %s\n",
> + drm_get_format_name(target_fb->pixel_format, &format_name));
> - kfree(format_name);
> return -EINVAL;
> }
>
> @@ -1473,7 +1472,7 @@ static int avivo_crtc_do_set_base(struct drm_crtc *crtc,
> u32 viewport_w, viewport_h;
> int r;
> bool bypass_lut = false;
> - char *format_name;
> + struct drm_format_name_buf format_name;
>
> /* no fb bound */
> if (!atomic && !crtc->primary->fb) {
> @@ -1563,9 +1562,8 @@ static int avivo_crtc_do_set_base(struct drm_crtc *crtc,
> bypass_lut = true;
> break;
> default:
> - format_name = drm_get_format_name(target_fb->pixel_format);
> - DRM_ERROR("Unsupported screen format %s\n", format_name);
> + DRM_ERROR("Unsupported screen format %s\n",
> + drm_get_format_name(target_fb->pixel_format, &format_name));
> - kfree(format_name);
> return -EINVAL;
> }
>
> diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c b/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c
> index c965514..e3f68cc 100644
> --- a/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c
> +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c
> @@ -985,8 +985,9 @@ static struct drm_framebuffer *vmw_kms_fb_create(struct drm_device *dev,
>
> info = drm_format_info(mode_cmd2->pixel_format);
> if (!info || !info->depth) {
> + struct drm_format_name_buf format_name;
> DRM_ERROR("Unsupported framebuffer format %s\n",
> - drm_get_format_name(mode_cmd2->pixel_format));
> + drm_get_format_name(mode_cmd2->pixel_format, &format_name));
> return ERR_PTR(-EINVAL);
> }

--
Jani Nikula, Intel Open Source Technology Center

2016-11-07 14:46:48

by Rob Clark

[permalink] [raw]

Subject: Re: [PATCH v2] drm: move allocation out of drm_get_format_name()

On Sun, Nov 6, 2016 at 7:48 PM, Eric Engestrom <[email protected]> wrote:
> Fixes: 90844f00049e9f42573fd31d7c32e8fd31d3fd07
>
> drm: make drm_get_format_name thread-safe
>
> Signed-off-by: Eric Engestrom <[email protected]>
> [danvet: Clarify that the returned pointer must be freed with
> kfree().]
> Signed-off-by: Daniel Vetter <[email protected]>
>
> Cc: Rob Clark <[email protected]>
> Cc: Christian König <[email protected]>
> Suggested-by: Ville Syrjälä <[email protected]>
> Signed-off-by: Eric Engestrom <[email protected]>

Thanks,

Acked-by: Rob Clark <[email protected]>

> ---
>
> v2: use single-field struct instead of typedef to let the compiler
> enforce the type (Christian König)
>
> ---
> include/drm/drm_fourcc.h | 10 +++++-
> drivers/gpu/drm/drm_fourcc.c | 14 +++------
> drivers/gpu/drm/amd/amdgpu/dce_v10_0.c | 7 ++---
> drivers/gpu/drm/amd/amdgpu/dce_v11_0.c | 7 ++---
> drivers/gpu/drm/amd/amdgpu/dce_v6_0.c | 3 +-
> drivers/gpu/drm/amd/amdgpu/dce_v8_0.c | 7 ++---
> drivers/gpu/drm/drm_atomic.c | 7 +++--
> drivers/gpu/drm/drm_crtc.c | 7 +++--
> drivers/gpu/drm/drm_framebuffer.c | 7 +++--
> drivers/gpu/drm/drm_modeset_helper.c | 7 +++--
> drivers/gpu/drm/drm_plane.c | 7 +++--
> drivers/gpu/drm/hisilicon/kirin/kirin_drm_ade.c | 7 ++---
> drivers/gpu/drm/i915/i915_debugfs.c | 10 +++---
> drivers/gpu/drm/i915/intel_atomic_plane.c | 8 ++---
> drivers/gpu/drm/i915/intel_display.c | 41 ++++++++++---------------
> drivers/gpu/drm/radeon/atombios_crtc.c | 14 ++++-----
> drivers/gpu/drm/vmwgfx/vmwgfx_kms.c | 3 +-
> 17 files changed, 80 insertions(+), 86 deletions(-)
>
> diff --git a/include/drm/drm_fourcc.h b/include/drm/drm_fourcc.h
> index dc0aafa..4b03ca0 100644
> --- a/include/drm/drm_fourcc.h
> +++ b/include/drm/drm_fourcc.h
> @@ -45,6 +45,14 @@ struct drm_format_info {
> u8 vsub;
> };
>
> +/**
> + * struct drm_format_name_buf - name of a DRM format
> + * @str: string buffer containing the format name
> + */
> +struct drm_format_name_buf {
> + char str[32];
> +};
> +
> const struct drm_format_info *__drm_format_info(u32 format);
> const struct drm_format_info *drm_format_info(u32 format);
> uint32_t drm_mode_legacy_fb_format(uint32_t bpp, uint32_t depth);
> @@ -54,6 +62,6 @@ int drm_format_horz_chroma_subsampling(uint32_t format);
> int drm_format_vert_chroma_subsampling(uint32_t format);
> int drm_format_plane_width(int width, uint32_t format, int plane);
> int drm_format_plane_height(int height, uint32_t format, int plane);
> -char *drm_get_format_name(uint32_t format) __malloc;
> +char *drm_get_format_name(uint32_t format, struct drm_format_name_buf *buf);
>
> #endif /* __DRM_FOURCC_H__ */
> diff --git a/drivers/gpu/drm/drm_fourcc.c b/drivers/gpu/drm/drm_fourcc.c
> index cbb8b77..99b0b60 100644
> --- a/drivers/gpu/drm/drm_fourcc.c
> +++ b/drivers/gpu/drm/drm_fourcc.c
> @@ -79,17 +79,13 @@ uint32_t drm_mode_legacy_fb_format(uint32_t bpp, uint32_t depth)
> EXPORT_SYMBOL(drm_mode_legacy_fb_format);
>
> /**
> - * drm_get_format_name - return a string for drm fourcc format
> + * drm_get_format_name - fill a string with a drm fourcc format's name
> * @format: format to compute name of
> + * @buf: caller-supplied buffer
> - *
> - * Note that the buffer returned by this function is owned by the caller
> - * and will need to be freed using kfree().
> */
> -char *drm_get_format_name(uint32_t format)
> +char *drm_get_format_name(uint32_t format, struct drm_format_name_buf *buf)
> {
> - char *buf = kmalloc(32, GFP_KERNEL);
> -
> - snprintf(buf, 32,
> + snprintf(buf->str, sizeof(buf->str),
> "%c%c%c%c %s-endian (0x%08x)",
> printable_char(format & 0xff),
> printable_char((format >> 8) & 0xff),
> @@ -98,7 +94,7 @@ char *drm_get_format_name(uint32_t format)
> format & DRM_FORMAT_BIG_ENDIAN ? "big" : "little",
> format);
>
> - return buf;
> + return buf->str;
> }
> EXPORT_SYMBOL(drm_get_format_name);
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/dce_v10_0.c b/drivers/gpu/drm/amd/amdgpu/dce_v10_0.c
> index 199d3f7..2924cdd 100644
> --- a/drivers/gpu/drm/amd/amdgpu/dce_v10_0.c
> +++ b/drivers/gpu/drm/amd/amdgpu/dce_v10_0.c
> @@ -2032,7 +2032,7 @@ static int dce_v10_0_crtc_do_set_base(struct drm_crtc *crtc,
> u32 tmp, viewport_w, viewport_h;
> int r;
> bool bypass_lut = false;
> - char *format_name;
> + struct drm_format_name_buf format_name;
>
> /* no fb bound */
> if (!atomic && !crtc->primary->fb) {
> @@ -2144,9 +2144,8 @@ static int dce_v10_0_crtc_do_set_base(struct drm_crtc *crtc,
> bypass_lut = true;
> break;
> default:
> - format_name = drm_get_format_name(target_fb->pixel_format);
> - DRM_ERROR("Unsupported screen format %s\n", format_name);
> + DRM_ERROR("Unsupported screen format %s\n",
> + drm_get_format_name(target_fb->pixel_format, &format_name));
> - kfree(format_name);
> return -EINVAL;
> }
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/dce_v11_0.c b/drivers/gpu/drm/amd/amdgpu/dce_v11_0.c
> index ecd000e..f0e3c5c 100644
> --- a/drivers/gpu/drm/amd/amdgpu/dce_v11_0.c
> +++ b/drivers/gpu/drm/amd/amdgpu/dce_v11_0.c
> @@ -2013,7 +2013,7 @@ static int dce_v11_0_crtc_do_set_base(struct drm_crtc *crtc,
> u32 tmp, viewport_w, viewport_h;
> int r;
> bool bypass_lut = false;
> - char *format_name;
> + struct drm_format_name_buf format_name;
>
> /* no fb bound */
> if (!atomic && !crtc->primary->fb) {
> @@ -2125,9 +2125,8 @@ static int dce_v11_0_crtc_do_set_base(struct drm_crtc *crtc,
> bypass_lut = true;
> break;
> default:
> - format_name = drm_get_format_name(target_fb->pixel_format);
> - DRM_ERROR("Unsupported screen format %s\n", format_name);
> + DRM_ERROR("Unsupported screen format %s\n",
> + drm_get_format_name(target_fb->pixel_format, &format_name));
> - kfree(format_name);
> return -EINVAL;
> }
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/dce_v6_0.c b/drivers/gpu/drm/amd/amdgpu/dce_v6_0.c
> index 44547f9..5c6b82f 100644
> --- a/drivers/gpu/drm/amd/amdgpu/dce_v6_0.c
> +++ b/drivers/gpu/drm/amd/amdgpu/dce_v6_0.c
> @@ -1456,6 +1456,7 @@ static int dce_v6_0_crtc_do_set_base(struct drm_crtc *crtc,
> u32 viewport_w, viewport_h;
> int r;
> bool bypass_lut = false;
> + struct drm_format_name_buf format_name;
>
> /* no fb bound */
> if (!atomic && !crtc->primary->fb) {
> @@ -1559,7 +1560,7 @@ static int dce_v6_0_crtc_do_set_base(struct drm_crtc *crtc,
> break;
> default:
> DRM_ERROR("Unsupported screen format %s\n",
> - drm_get_format_name(target_fb->pixel_format));
> + drm_get_format_name(target_fb->pixel_format, &format_name));
> return -EINVAL;
> }
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/dce_v8_0.c b/drivers/gpu/drm/amd/amdgpu/dce_v8_0.c
> index 979aedf..5aef19d 100644
> --- a/drivers/gpu/drm/amd/amdgpu/dce_v8_0.c
> +++ b/drivers/gpu/drm/amd/amdgpu/dce_v8_0.c
> @@ -1910,7 +1910,7 @@ static int dce_v8_0_crtc_do_set_base(struct drm_crtc *crtc,
> u32 viewport_w, viewport_h;
> int r;
> bool bypass_lut = false;
> - char *format_name;
> + struct drm_format_name_buf format_name;
>
> /* no fb bound */
> if (!atomic && !crtc->primary->fb) {
> @@ -2015,9 +2015,8 @@ static int dce_v8_0_crtc_do_set_base(struct drm_crtc *crtc,
> bypass_lut = true;
> break;
> default:
> - format_name = drm_get_format_name(target_fb->pixel_format);
> - DRM_ERROR("Unsupported screen format %s\n", format_name);
> + DRM_ERROR("Unsupported screen format %s\n",
> + drm_get_format_name(target_fb->pixel_format, &format_name));
> - kfree(format_name);
> return -EINVAL;
> }
>
> diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c
> index c32fb3c..f29d3c5 100644
> --- a/drivers/gpu/drm/drm_atomic.c
> +++ b/drivers/gpu/drm/drm_atomic.c
> @@ -835,9 +835,10 @@ static int drm_atomic_plane_check(struct drm_plane *plane,
> /* Check whether this plane supports the fb pixel format. */
> ret = drm_plane_check_pixel_format(plane, state->fb->pixel_format);
> if (ret) {
> - char *format_name = drm_get_format_name(state->fb->pixel_format);
> - DRM_DEBUG_ATOMIC("Invalid pixel format %s\n", format_name);
> + struct drm_format_name_buf format_name;
> + DRM_DEBUG_ATOMIC("Invalid pixel format %s\n",
> + drm_get_format_name(state->fb->pixel_format,
> + &format_name));
> - kfree(format_name);
> return ret;
> }
>
> diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
> index 13441e2..08ac216 100644
> --- a/drivers/gpu/drm/drm_crtc.c
> +++ b/drivers/gpu/drm/drm_crtc.c
> @@ -827,9 +827,10 @@ int drm_mode_setcrtc(struct drm_device *dev, void *data,
> ret = drm_plane_check_pixel_format(crtc->primary,
> fb->pixel_format);
> if (ret) {
> - char *format_name = drm_get_format_name(fb->pixel_format);
> - DRM_DEBUG_KMS("Invalid pixel format %s\n", format_name);
> + struct drm_format_name_buf format_name;
> + DRM_DEBUG_KMS("Invalid pixel format %s\n",
> + drm_get_format_name(fb->pixel_format,
> + &format_name));
> - kfree(format_name);
> goto out;
> }
> }
> diff --git a/drivers/gpu/drm/drm_framebuffer.c b/drivers/gpu/drm/drm_framebuffer.c
> index 49fd7db..df6b180 100644
> --- a/drivers/gpu/drm/drm_framebuffer.c
> +++ b/drivers/gpu/drm/drm_framebuffer.c
> @@ -133,9 +133,10 @@ static int framebuffer_check(const struct drm_mode_fb_cmd2 *r)
>
> info = __drm_format_info(r->pixel_format & ~DRM_FORMAT_BIG_ENDIAN);
> if (!info) {
> - char *format_name = drm_get_format_name(r->pixel_format);
> - DRM_DEBUG_KMS("bad framebuffer format %s\n", format_name);
> + struct drm_format_name_buf format_name;
> + DRM_DEBUG_KMS("bad framebuffer format %s\n",
> + drm_get_format_name(r->pixel_format,
> + &format_name));
> - kfree(format_name);
> return -EINVAL;
> }
>
> diff --git a/drivers/gpu/drm/drm_modeset_helper.c b/drivers/gpu/drm/drm_modeset_helper.c
> index 2544dfe..2f452b3 100644
> --- a/drivers/gpu/drm/drm_modeset_helper.c
> +++ b/drivers/gpu/drm/drm_modeset_helper.c
> @@ -75,10 +75,11 @@ void drm_helper_mode_fill_fb_struct(struct drm_framebuffer *fb,
>
> info = drm_format_info(mode_cmd->pixel_format);
> if (!info || !info->depth) {
> - char *format_name = drm_get_format_name(mode_cmd->pixel_format);
> + struct drm_format_name_buf format_name;
>
> - DRM_DEBUG_KMS("non-RGB pixel format %s\n", format_name);
> + DRM_DEBUG_KMS("non-RGB pixel format %s\n",
> + drm_get_format_name(mode_cmd->pixel_format,
> + &format_name));
> - kfree(format_name);
>
> fb->depth = 0;
> fb->bits_per_pixel = 0;
> diff --git a/drivers/gpu/drm/drm_plane.c b/drivers/gpu/drm/drm_plane.c
> index 249c0ae..2ba0c22 100644
> --- a/drivers/gpu/drm/drm_plane.c
> +++ b/drivers/gpu/drm/drm_plane.c
> @@ -479,9 +479,10 @@ static int __setplane_internal(struct drm_plane *plane,
> /* Check whether this plane supports the fb pixel format. */
> ret = drm_plane_check_pixel_format(plane, fb->pixel_format);
> if (ret) {
> - char *format_name = drm_get_format_name(fb->pixel_format);
> - DRM_DEBUG_KMS("Invalid pixel format %s\n", format_name);
> + struct drm_format_name_buf format_name;
> + DRM_DEBUG_KMS("Invalid pixel format %s\n",
> + drm_get_format_name(fb->pixel_format,
> + &format_name));
> - kfree(format_name);
> goto out;
> }
>
> diff --git a/drivers/gpu/drm/hisilicon/kirin/kirin_drm_ade.c b/drivers/gpu/drm/hisilicon/kirin/kirin_drm_ade.c
> index 7e7a4d4..afc2b5d 100644
> --- a/drivers/gpu/drm/hisilicon/kirin/kirin_drm_ade.c
> +++ b/drivers/gpu/drm/hisilicon/kirin/kirin_drm_ade.c
> @@ -608,17 +608,16 @@ static void ade_rdma_set(void __iomem *base, struct drm_framebuffer *fb,
> u32 ch, u32 y, u32 in_h, u32 fmt)
> {
> struct drm_gem_cma_object *obj = drm_fb_cma_get_gem_obj(fb, 0);
> - char *format_name;
> + struct drm_format_name_buf format_name;
> u32 reg_ctrl, reg_addr, reg_size, reg_stride, reg_space, reg_en;
> u32 stride = fb->pitches[0];
> u32 addr = (u32)obj->paddr + y * stride;
>
> DRM_DEBUG_DRIVER("rdma%d: (y=%d, height=%d), stride=%d, paddr=0x%x\n",
> ch + 1, y, in_h, stride, (u32)obj->paddr);
> - format_name = drm_get_format_name(fb->pixel_format);
> DRM_DEBUG_DRIVER("addr=0x%x, fb:%dx%d, pixel_format=%d(%s)\n",
> - addr, fb->width, fb->height, fmt, format_name);
> + addr, fb->width, fb->height, fmt,
> + drm_get_format_name(fb->pixel_format, &format_name));
> - kfree(format_name);
>
> /* get reg offset */
> reg_ctrl = RD_CH_CTRL(ch);
> diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
> index 20638d2..670423e 100644
> --- a/drivers/gpu/drm/i915/i915_debugfs.c
> +++ b/drivers/gpu/drm/i915/i915_debugfs.c
> @@ -2971,7 +2971,7 @@ static void intel_plane_info(struct seq_file *m, struct intel_crtc *intel_crtc)
> for_each_intel_plane_on_crtc(dev, intel_crtc, intel_plane) {
> struct drm_plane_state *state;
> struct drm_plane *plane = &intel_plane->base;
> - char *format_name;
> + struct drm_format_name_buf format_name;
>
> if (!plane->state) {
> seq_puts(m, "plane->state is NULL!\n");
> @@ -2981,9 +2981,9 @@ static void intel_plane_info(struct seq_file *m, struct intel_crtc *intel_crtc)
> state = plane->state;
>
> if (state->fb) {
> - format_name = drm_get_format_name(state->fb->pixel_format);
> + drm_get_format_name(state->fb->pixel_format, &format_name);
> } else {
> - format_name = kstrdup("N/A", GFP_KERNEL);
> + sprintf(format_name.str, "N/A");
> }
>
> seq_printf(m, "\t--Plane id %d: type=%s, crtc_pos=%4dx%4d, crtc_size=%4dx%4d, src_pos=%d.%04ux%d.%04u, src_size=%d.%04ux%d.%04u, format=%s, rotation=%s\n",
> @@ -2999,10 +2999,8 @@ static void intel_plane_info(struct seq_file *m, struct intel_crtc *intel_crtc)
> ((state->src_w & 0xffff) * 15625) >> 10,
> (state->src_h >> 16),
> ((state->src_h & 0xffff) * 15625) >> 10,
> - format_name,
> + format_name.str,
> plane_rotation(state->rotation));
> -
> - kfree(format_name);
> }
> }
>
> diff --git a/drivers/gpu/drm/i915/intel_atomic_plane.c b/drivers/gpu/drm/i915/intel_atomic_plane.c
> index c762ae5..6c76e3d 100644
> --- a/drivers/gpu/drm/i915/intel_atomic_plane.c
> +++ b/drivers/gpu/drm/i915/intel_atomic_plane.c
> @@ -143,7 +143,7 @@ static int intel_plane_atomic_check(struct drm_plane *plane,
> crtc_state->base.enable ? crtc_state->pipe_src_h : 0;
>
> if (state->fb && drm_rotation_90_or_270(state->rotation)) {
> - char *format_name;
> + struct drm_format_name_buf format_name;
>
> if (!(state->fb->modifier[0] == I915_FORMAT_MOD_Y_TILED ||
> state->fb->modifier[0] == I915_FORMAT_MOD_Yf_TILED)) {
> @@ -159,9 +159,9 @@ static int intel_plane_atomic_check(struct drm_plane *plane,
> switch (state->fb->pixel_format) {
> case DRM_FORMAT_C8:
> case DRM_FORMAT_RGB565:
> - format_name = drm_get_format_name(state->fb->pixel_format);
> - DRM_DEBUG_KMS("Unsupported pixel format %s for 90/270!\n", format_name);
> + DRM_DEBUG_KMS("Unsupported pixel format %s for 90/270!\n",
> + drm_get_format_name(state->fb->pixel_format,
> + &format_name));
> - kfree(format_name);
> return -EINVAL;
>
> default:
> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> index 6f8f6ec..8209170 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -12871,7 +12871,7 @@ static void intel_dump_pipe_config(struct intel_crtc *crtc,
>
> DRM_DEBUG_KMS("planes on this crtc\n");
> list_for_each_entry(plane, &dev->mode_config.plane_list, head) {
> - char *format_name;
> + struct drm_format_name_buf format_name;
> intel_plane = to_intel_plane(plane);
> if (intel_plane->pipe != crtc->pipe)
> continue;
> @@ -12884,12 +12884,11 @@ static void intel_dump_pipe_config(struct intel_crtc *crtc,
> continue;
> }
>
> - format_name = drm_get_format_name(fb->pixel_format);
> -
> DRM_DEBUG_KMS("[PLANE:%d:%s] enabled",
> plane->base.id, plane->name);
> DRM_DEBUG_KMS("\tFB:%d, fb = %ux%u format = %s",
> - fb->base.id, fb->width, fb->height, format_name);
> + fb->base.id, fb->width, fb->height,
> + drm_get_format_name(fb->pixel_format, &format_name));
> DRM_DEBUG_KMS("\tscaler:%d src %dx%d+%d+%d dst %dx%d+%d+%d\n",
> state->scaler_id,
> state->base.src.x1 >> 16,
> @@ -12899,8 +12898,6 @@ static void intel_dump_pipe_config(struct intel_crtc *crtc,
> state->base.dst.x1, state->base.dst.y1,
> drm_rect_width(&state->base.dst),
> drm_rect_height(&state->base.dst));
> -
> - kfree(format_name);
> }
> }
>
> @@ -15749,7 +15746,7 @@ static int intel_framebuffer_init(struct drm_device *dev,
> unsigned int tiling = i915_gem_object_get_tiling(obj);
> int ret;
> u32 pitch_limit, stride_alignment;
> - char *format_name;
> + struct drm_format_name_buf format_name;
>
> WARN_ON(!mutex_is_locked(&dev->struct_mutex));
>
> @@ -15840,18 +15837,16 @@ static int intel_framebuffer_init(struct drm_device *dev,
> break;
> case DRM_FORMAT_XRGB1555:
> if (INTEL_INFO(dev)->gen > 3) {
> - format_name = drm_get_format_name(mode_cmd->pixel_format);
> - DRM_DEBUG("unsupported pixel format: %s\n", format_name);
> + DRM_DEBUG("unsupported pixel format: %s\n",
> + drm_get_format_name(mode_cmd->pixel_format, &format_name));
> - kfree(format_name);
> return -EINVAL;
> }
> break;
> case DRM_FORMAT_ABGR8888:
> if (!IS_VALLEYVIEW(dev_priv) && !IS_CHERRYVIEW(dev_priv) &&
> INTEL_INFO(dev)->gen < 9) {
> - format_name = drm_get_format_name(mode_cmd->pixel_format);
> - DRM_DEBUG("unsupported pixel format: %s\n", format_name);
> + DRM_DEBUG("unsupported pixel format: %s\n",
> + drm_get_format_name(mode_cmd->pixel_format, &format_name));
> - kfree(format_name);
> return -EINVAL;
> }
> break;
> @@ -15859,17 +15854,15 @@ static int intel_framebuffer_init(struct drm_device *dev,
> case DRM_FORMAT_XRGB2101010:
> case DRM_FORMAT_XBGR2101010:
> if (INTEL_INFO(dev)->gen < 4) {
> - format_name = drm_get_format_name(mode_cmd->pixel_format);
> - DRM_DEBUG("unsupported pixel format: %s\n", format_name);
> + DRM_DEBUG("unsupported pixel format: %s\n",
> + drm_get_format_name(mode_cmd->pixel_format, &format_name));
> - kfree(format_name);
> return -EINVAL;
> }
> break;
> case DRM_FORMAT_ABGR2101010:
> if (!IS_VALLEYVIEW(dev_priv) && !IS_CHERRYVIEW(dev_priv)) {
> - format_name = drm_get_format_name(mode_cmd->pixel_format);
> - DRM_DEBUG("unsupported pixel format: %s\n", format_name);
> + DRM_DEBUG("unsupported pixel format: %s\n",
> + drm_get_format_name(mode_cmd->pixel_format, &format_name));
> - kfree(format_name);
> return -EINVAL;
> }
> break;
> @@ -15878,16 +15871,14 @@ static int intel_framebuffer_init(struct drm_device *dev,
> case DRM_FORMAT_YVYU:
> case DRM_FORMAT_VYUY:
> if (INTEL_INFO(dev)->gen < 5) {
> - format_name = drm_get_format_name(mode_cmd->pixel_format);
> - DRM_DEBUG("unsupported pixel format: %s\n", format_name);
> + DRM_DEBUG("unsupported pixel format: %s\n",
> + drm_get_format_name(mode_cmd->pixel_format, &format_name));
> - kfree(format_name);
> return -EINVAL;
> }
> break;
> default:
> - format_name = drm_get_format_name(mode_cmd->pixel_format);
> - DRM_DEBUG("unsupported pixel format: %s\n", format_name);
> + DRM_DEBUG("unsupported pixel format: %s\n",
> + drm_get_format_name(mode_cmd->pixel_format, &format_name));
> - kfree(format_name);
> return -EINVAL;
> }
>
> diff --git a/drivers/gpu/drm/radeon/atombios_crtc.c b/drivers/gpu/drm/radeon/atombios_crtc.c
> index 74f99ba..05f4ebe 100644
> --- a/drivers/gpu/drm/radeon/atombios_crtc.c
> +++ b/drivers/gpu/drm/radeon/atombios_crtc.c
> @@ -1156,7 +1156,7 @@ static int dce4_crtc_do_set_base(struct drm_crtc *crtc,
> u32 tmp, viewport_w, viewport_h;
> int r;
> bool bypass_lut = false;
> - char *format_name;
> + struct drm_format_name_buf format_name;
>
> /* no fb bound */
> if (!atomic && !crtc->primary->fb) {
> @@ -1260,9 +1260,8 @@ static int dce4_crtc_do_set_base(struct drm_crtc *crtc,
> bypass_lut = true;
> break;
> default:
> - format_name = drm_get_format_name(target_fb->pixel_format);
> - DRM_ERROR("Unsupported screen format %s\n", format_name);
> + DRM_ERROR("Unsupported screen format %s\n",
> + drm_get_format_name(target_fb->pixel_format, &format_name));
> - kfree(format_name);
> return -EINVAL;
> }
>
> @@ -1473,7 +1472,7 @@ static int avivo_crtc_do_set_base(struct drm_crtc *crtc,
> u32 viewport_w, viewport_h;
> int r;
> bool bypass_lut = false;
> - char *format_name;
> + struct drm_format_name_buf format_name;
>
> /* no fb bound */
> if (!atomic && !crtc->primary->fb) {
> @@ -1563,9 +1562,8 @@ static int avivo_crtc_do_set_base(struct drm_crtc *crtc,
> bypass_lut = true;
> break;
> default:
> - format_name = drm_get_format_name(target_fb->pixel_format);
> - DRM_ERROR("Unsupported screen format %s\n", format_name);
> + DRM_ERROR("Unsupported screen format %s\n",
> + drm_get_format_name(target_fb->pixel_format, &format_name));
> - kfree(format_name);
> return -EINVAL;
> }
>
> diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c b/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c
> index c965514..e3f68cc 100644
> --- a/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c
> +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c
> @@ -985,8 +985,9 @@ static struct drm_framebuffer *vmw_kms_fb_create(struct drm_device *dev,
>
> info = drm_format_info(mode_cmd2->pixel_format);
> if (!info || !info->depth) {
> + struct drm_format_name_buf format_name;
> DRM_ERROR("Unsupported framebuffer format %s\n",
> - drm_get_format_name(mode_cmd2->pixel_format));
> + drm_get_format_name(mode_cmd2->pixel_format, &format_name));
> return ERR_PTR(-EINVAL);
> }
>
> --
> Cheers,
> Eric
>

2016-11-07 17:12:54

[permalink] [raw]

Subject: Re: [PATCH v2] drm: move allocation out of drm_get_format_name()

On Monday, 2016-11-07 10:10:13 +0200, Jani Nikula wrote:
> On Mon, 07 Nov 2016, Eric Engestrom <[email protected]> wrote:
> > Fixes: 90844f00049e9f42573fd31d7c32e8fd31d3fd07
> >
> > drm: make drm_get_format_name thread-safe
> >
> > Signed-off-by: Eric Engestrom <[email protected]>
> > [danvet: Clarify that the returned pointer must be freed with
> > kfree().]
> > Signed-off-by: Daniel Vetter <[email protected]>
>
> The Fixes: format is:
>
> Fixes: 90844f00049e ("drm: make drm_get_format_name thread-safe")
>
> But is this a fix, really, or just an improvement? What exactly is the
> bug being fixed? The commit message is not sufficient.

"The function's behaviour was changed in 90844f00049e, without changing
its signature, causing people to keep using it the old way without
realising they were now leaking memory.
Rob Clark also noticed it was also allocating GFP_KERNEL memory in
atomic contexts, breaking them.

Instead of having to allocate GFP_ATOMIC memory and fixing the callers
to make them cleanup the memory afterwards, let's change the function's
signature by having the caller take care of the memory and passing it to
the function.
The new parameter is a single-field struct in order to enforce the size
of its buffer and help callers to correctly manage their memory."

Does this sound good?

> > @@ -54,6 +62,6 @@ int drm_format_horz_chroma_subsampling(uint32_t format);
> > int drm_format_vert_chroma_subsampling(uint32_t format);
> > int drm_format_plane_width(int width, uint32_t format, int plane);
> > int drm_format_plane_height(int height, uint32_t format, int plane);
> > -char *drm_get_format_name(uint32_t format) __malloc;
> > +char *drm_get_format_name(uint32_t format, struct drm_format_name_buf *buf);
>
> I wonder if it would be better to make that return "const char *". If
> the user really wants to look under the hood, there's buf->str. *shrug*

Good idea, I'll do that in v3 with the proper commit msg and tags. It'll
have to wait another day though, -ENOTIME and all.

>
> With the commit message improved,
>
> Reviewed-by: Jani Nikula <[email protected]>

Cheers :)
Eric

2016-11-07 17:38:47

[permalink] [raw]

Subject: Re: [PATCH v2] drm: move allocation out of drm_get_format_name()

On Mon, 07 Nov 2016, Eric Engestrom <[email protected]> wrote:
> On Monday, 2016-11-07 10:10:13 +0200, Jani Nikula wrote:
>> On Mon, 07 Nov 2016, Eric Engestrom <[email protected]> wrote:
>> > Fixes: 90844f00049e9f42573fd31d7c32e8fd31d3fd07
>> >
>> > drm: make drm_get_format_name thread-safe
>> >
>> > Signed-off-by: Eric Engestrom <[email protected]>
>> > [danvet: Clarify that the returned pointer must be freed with
>> > kfree().]
>> > Signed-off-by: Daniel Vetter <[email protected]>
>>
>> The Fixes: format is:
>>
>> Fixes: 90844f00049e ("drm: make drm_get_format_name thread-safe")
>>
>> But is this a fix, really, or just an improvement? What exactly is the
>> bug being fixed? The commit message is not sufficient.
>
> "The function's behaviour was changed in 90844f00049e, without changing
> its signature, causing people to keep using it the old way without
> realising they were now leaking memory.
> Rob Clark also noticed it was also allocating GFP_KERNEL memory in
> atomic contexts, breaking them.
>
> Instead of having to allocate GFP_ATOMIC memory and fixing the callers
> to make them cleanup the memory afterwards, let's change the function's
> signature by having the caller take care of the memory and passing it to
> the function.
> The new parameter is a single-field struct in order to enforce the size
> of its buffer and help callers to correctly manage their memory."
>
> Does this sound good?

It's fine; no need to go overboard. ;)

BR,
Jani.

>
>> > @@ -54,6 +62,6 @@ int drm_format_horz_chroma_subsampling(uint32_t format);
>> > int drm_format_vert_chroma_subsampling(uint32_t format);
>> > int drm_format_plane_width(int width, uint32_t format, int plane);
>> > int drm_format_plane_height(int height, uint32_t format, int plane);
>> > -char *drm_get_format_name(uint32_t format) __malloc;
>> > +char *drm_get_format_name(uint32_t format, struct drm_format_name_buf *buf);
>>
>> I wonder if it would be better to make that return "const char *". If
>> the user really wants to look under the hood, there's buf->str. *shrug*
>
> Good idea, I'll do that in v3 with the proper commit msg and tags. It'll
> have to wait another day though, -ENOTIME and all.
>
>>
>> With the commit message improved,
>>
>> Reviewed-by: Jani Nikula <[email protected]>
>
> Cheers :)
> Eric

--
Jani Nikula, Intel Open Source Technology Center

2016-11-07 18:12:46

by Sinclair Yeh

[permalink] [raw]

Subject: Re: [PATCH v2] drm: move allocation out of drm_get_format_name()

Thomas has already acked the earlier version, but in case you need
it for this one, too.

vmwgfx portion: Acked-by: Sinclair Yeh <[email protected]>

On Mon, Nov 07, 2016 at 12:48:09AM +0000, Eric Engestrom wrote:
> Fixes: 90844f00049e9f42573fd31d7c32e8fd31d3fd07
>
> drm: make drm_get_format_name thread-safe
>
> Signed-off-by: Eric Engestrom <[email protected]>
> [danvet: Clarify that the returned pointer must be freed with
> kfree().]
> Signed-off-by: Daniel Vetter <[email protected]>
>
> Cc: Rob Clark <[email protected]>
> Cc: Christian K?nig <[email protected]>
> Suggested-by: Ville Syrj?l? <[email protected]>
> Signed-off-by: Eric Engestrom <[email protected]>
> ---
>
> v2: use single-field struct instead of typedef to let the compiler
> enforce the type (Christian K?nig)
>
> ---
> include/drm/drm_fourcc.h | 10 +++++-
> drivers/gpu/drm/drm_fourcc.c | 14 +++------
> drivers/gpu/drm/amd/amdgpu/dce_v10_0.c | 7 ++---
> drivers/gpu/drm/amd/amdgpu/dce_v11_0.c | 7 ++---
> drivers/gpu/drm/amd/amdgpu/dce_v6_0.c | 3 +-
> drivers/gpu/drm/amd/amdgpu/dce_v8_0.c | 7 ++---
> drivers/gpu/drm/drm_atomic.c | 7 +++--
> drivers/gpu/drm/drm_crtc.c | 7 +++--
> drivers/gpu/drm/drm_framebuffer.c | 7 +++--
> drivers/gpu/drm/drm_modeset_helper.c | 7 +++--
> drivers/gpu/drm/drm_plane.c | 7 +++--
> drivers/gpu/drm/hisilicon/kirin/kirin_drm_ade.c | 7 ++---
> drivers/gpu/drm/i915/i915_debugfs.c | 10 +++---
> drivers/gpu/drm/i915/intel_atomic_plane.c | 8 ++---
> drivers/gpu/drm/i915/intel_display.c | 41 ++++++++++---------------
> drivers/gpu/drm/radeon/atombios_crtc.c | 14 ++++-----
> drivers/gpu/drm/vmwgfx/vmwgfx_kms.c | 3 +-
> 17 files changed, 80 insertions(+), 86 deletions(-)
>
> diff --git a/include/drm/drm_fourcc.h b/include/drm/drm_fourcc.h
> index dc0aafa..4b03ca0 100644
> --- a/include/drm/drm_fourcc.h
> +++ b/include/drm/drm_fourcc.h
> @@ -45,6 +45,14 @@ struct drm_format_info {
> u8 vsub;
> };
>
> +/**
> + * struct drm_format_name_buf - name of a DRM format
> + * @str: string buffer containing the format name
> + */
> +struct drm_format_name_buf {
> + char str[32];
> +};
> +
> const struct drm_format_info *__drm_format_info(u32 format);
> const struct drm_format_info *drm_format_info(u32 format);
> uint32_t drm_mode_legacy_fb_format(uint32_t bpp, uint32_t depth);
> @@ -54,6 +62,6 @@ int drm_format_horz_chroma_subsampling(uint32_t format);
> int drm_format_vert_chroma_subsampling(uint32_t format);
> int drm_format_plane_width(int width, uint32_t format, int plane);
> int drm_format_plane_height(int height, uint32_t format, int plane);
> -char *drm_get_format_name(uint32_t format) __malloc;
> +char *drm_get_format_name(uint32_t format, struct drm_format_name_buf *buf);
>
> #endif /* __DRM_FOURCC_H__ */
> diff --git a/drivers/gpu/drm/drm_fourcc.c b/drivers/gpu/drm/drm_fourcc.c
> index cbb8b77..99b0b60 100644
> --- a/drivers/gpu/drm/drm_fourcc.c
> +++ b/drivers/gpu/drm/drm_fourcc.c
> @@ -79,17 +79,13 @@ uint32_t drm_mode_legacy_fb_format(uint32_t bpp, uint32_t depth)
> EXPORT_SYMBOL(drm_mode_legacy_fb_format);
>
> /**
> - * drm_get_format_name - return a string for drm fourcc format
> + * drm_get_format_name - fill a string with a drm fourcc format's name
> * @format: format to compute name of
> + * @buf: caller-supplied buffer
> - *
> - * Note that the buffer returned by this function is owned by the caller
> - * and will need to be freed using kfree().
> */
> -char *drm_get_format_name(uint32_t format)
> +char *drm_get_format_name(uint32_t format, struct drm_format_name_buf *buf)
> {
> - char *buf = kmalloc(32, GFP_KERNEL);
> -
> - snprintf(buf, 32,
> + snprintf(buf->str, sizeof(buf->str),
> "%c%c%c%c %s-endian (0x%08x)",
> printable_char(format & 0xff),
> printable_char((format >> 8) & 0xff),
> @@ -98,7 +94,7 @@ char *drm_get_format_name(uint32_t format)
> format & DRM_FORMAT_BIG_ENDIAN ? "big" : "little",
> format);
>
> - return buf;
> + return buf->str;
> }
> EXPORT_SYMBOL(drm_get_format_name);
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/dce_v10_0.c b/drivers/gpu/drm/amd/amdgpu/dce_v10_0.c
> index 199d3f7..2924cdd 100644
> --- a/drivers/gpu/drm/amd/amdgpu/dce_v10_0.c
> +++ b/drivers/gpu/drm/amd/amdgpu/dce_v10_0.c
> @@ -2032,7 +2032,7 @@ static int dce_v10_0_crtc_do_set_base(struct drm_crtc *crtc,
> u32 tmp, viewport_w, viewport_h;
> int r;
> bool bypass_lut = false;
> - char *format_name;
> + struct drm_format_name_buf format_name;
>
> /* no fb bound */
> if (!atomic && !crtc->primary->fb) {
> @@ -2144,9 +2144,8 @@ static int dce_v10_0_crtc_do_set_base(struct drm_crtc *crtc,
> bypass_lut = true;
> break;
> default:
> - format_name = drm_get_format_name(target_fb->pixel_format);
> - DRM_ERROR("Unsupported screen format %s\n", format_name);
> + DRM_ERROR("Unsupported screen format %s\n",
> + drm_get_format_name(target_fb->pixel_format, &format_name));
> - kfree(format_name);
> return -EINVAL;
> }
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/dce_v11_0.c b/drivers/gpu/drm/amd/amdgpu/dce_v11_0.c
> index ecd000e..f0e3c5c 100644
> --- a/drivers/gpu/drm/amd/amdgpu/dce_v11_0.c
> +++ b/drivers/gpu/drm/amd/amdgpu/dce_v11_0.c
> @@ -2013,7 +2013,7 @@ static int dce_v11_0_crtc_do_set_base(struct drm_crtc *crtc,
> u32 tmp, viewport_w, viewport_h;
> int r;
> bool bypass_lut = false;
> - char *format_name;
> + struct drm_format_name_buf format_name;
>
> /* no fb bound */
> if (!atomic && !crtc->primary->fb) {
> @@ -2125,9 +2125,8 @@ static int dce_v11_0_crtc_do_set_base(struct drm_crtc *crtc,
> bypass_lut = true;
> break;
> default:
> - format_name = drm_get_format_name(target_fb->pixel_format);
> - DRM_ERROR("Unsupported screen format %s\n", format_name);
> + DRM_ERROR("Unsupported screen format %s\n",
> + drm_get_format_name(target_fb->pixel_format, &format_name));
> - kfree(format_name);
> return -EINVAL;
> }
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/dce_v6_0.c b/drivers/gpu/drm/amd/amdgpu/dce_v6_0.c
> index 44547f9..5c6b82f 100644
> --- a/drivers/gpu/drm/amd/amdgpu/dce_v6_0.c
> +++ b/drivers/gpu/drm/amd/amdgpu/dce_v6_0.c
> @@ -1456,6 +1456,7 @@ static int dce_v6_0_crtc_do_set_base(struct drm_crtc *crtc,
> u32 viewport_w, viewport_h;
> int r;
> bool bypass_lut = false;
> + struct drm_format_name_buf format_name;
>
> /* no fb bound */
> if (!atomic && !crtc->primary->fb) {
> @@ -1559,7 +1560,7 @@ static int dce_v6_0_crtc_do_set_base(struct drm_crtc *crtc,
> break;
> default:
> DRM_ERROR("Unsupported screen format %s\n",
> - drm_get_format_name(target_fb->pixel_format));
> + drm_get_format_name(target_fb->pixel_format, &format_name));
> return -EINVAL;
> }
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/dce_v8_0.c b/drivers/gpu/drm/amd/amdgpu/dce_v8_0.c
> index 979aedf..5aef19d 100644
> --- a/drivers/gpu/drm/amd/amdgpu/dce_v8_0.c
> +++ b/drivers/gpu/drm/amd/amdgpu/dce_v8_0.c
> @@ -1910,7 +1910,7 @@ static int dce_v8_0_crtc_do_set_base(struct drm_crtc *crtc,
> u32 viewport_w, viewport_h;
> int r;
> bool bypass_lut = false;
> - char *format_name;
> + struct drm_format_name_buf format_name;
>
> /* no fb bound */
> if (!atomic && !crtc->primary->fb) {
> @@ -2015,9 +2015,8 @@ static int dce_v8_0_crtc_do_set_base(struct drm_crtc *crtc,
> bypass_lut = true;
> break;
> default:
> - format_name = drm_get_format_name(target_fb->pixel_format);
> - DRM_ERROR("Unsupported screen format %s\n", format_name);
> + DRM_ERROR("Unsupported screen format %s\n",
> + drm_get_format_name(target_fb->pixel_format, &format_name));
> - kfree(format_name);
> return -EINVAL;
> }
>
> diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c
> index c32fb3c..f29d3c5 100644
> --- a/drivers/gpu/drm/drm_atomic.c
> +++ b/drivers/gpu/drm/drm_atomic.c
> @@ -835,9 +835,10 @@ static int drm_atomic_plane_check(struct drm_plane *plane,
> /* Check whether this plane supports the fb pixel format. */
> ret = drm_plane_check_pixel_format(plane, state->fb->pixel_format);
> if (ret) {
> - char *format_name = drm_get_format_name(state->fb->pixel_format);
> - DRM_DEBUG_ATOMIC("Invalid pixel format %s\n", format_name);
> + struct drm_format_name_buf format_name;
> + DRM_DEBUG_ATOMIC("Invalid pixel format %s\n",
> + drm_get_format_name(state->fb->pixel_format,
> + &format_name));
> - kfree(format_name);
> return ret;
> }
>
> diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
> index 13441e2..08ac216 100644
> --- a/drivers/gpu/drm/drm_crtc.c
> +++ b/drivers/gpu/drm/drm_crtc.c
> @@ -827,9 +827,10 @@ int drm_mode_setcrtc(struct drm_device *dev, void *data,
> ret = drm_plane_check_pixel_format(crtc->primary,
> fb->pixel_format);
> if (ret) {
> - char *format_name = drm_get_format_name(fb->pixel_format);
> - DRM_DEBUG_KMS("Invalid pixel format %s\n", format_name);
> + struct drm_format_name_buf format_name;
> + DRM_DEBUG_KMS("Invalid pixel format %s\n",
> + drm_get_format_name(fb->pixel_format,
> + &format_name));
> - kfree(format_name);
> goto out;
> }
> }
> diff --git a/drivers/gpu/drm/drm_framebuffer.c b/drivers/gpu/drm/drm_framebuffer.c
> index 49fd7db..df6b180 100644
> --- a/drivers/gpu/drm/drm_framebuffer.c
> +++ b/drivers/gpu/drm/drm_framebuffer.c
> @@ -133,9 +133,10 @@ static int framebuffer_check(const struct drm_mode_fb_cmd2 *r)
>
> info = __drm_format_info(r->pixel_format & ~DRM_FORMAT_BIG_ENDIAN);
> if (!info) {
> - char *format_name = drm_get_format_name(r->pixel_format);
> - DRM_DEBUG_KMS("bad framebuffer format %s\n", format_name);
> + struct drm_format_name_buf format_name;
> + DRM_DEBUG_KMS("bad framebuffer format %s\n",
> + drm_get_format_name(r->pixel_format,
> + &format_name));
> - kfree(format_name);
> return -EINVAL;
> }
>
> diff --git a/drivers/gpu/drm/drm_modeset_helper.c b/drivers/gpu/drm/drm_modeset_helper.c
> index 2544dfe..2f452b3 100644
> --- a/drivers/gpu/drm/drm_modeset_helper.c
> +++ b/drivers/gpu/drm/drm_modeset_helper.c
> @@ -75,10 +75,11 @@ void drm_helper_mode_fill_fb_struct(struct drm_framebuffer *fb,
>
> info = drm_format_info(mode_cmd->pixel_format);
> if (!info || !info->depth) {
> - char *format_name = drm_get_format_name(mode_cmd->pixel_format);
> + struct drm_format_name_buf format_name;
>
> - DRM_DEBUG_KMS("non-RGB pixel format %s\n", format_name);
> + DRM_DEBUG_KMS("non-RGB pixel format %s\n",
> + drm_get_format_name(mode_cmd->pixel_format,
> + &format_name));
> - kfree(format_name);
>
> fb->depth = 0;
> fb->bits_per_pixel = 0;
> diff --git a/drivers/gpu/drm/drm_plane.c b/drivers/gpu/drm/drm_plane.c
> index 249c0ae..2ba0c22 100644
> --- a/drivers/gpu/drm/drm_plane.c
> +++ b/drivers/gpu/drm/drm_plane.c
> @@ -479,9 +479,10 @@ static int __setplane_internal(struct drm_plane *plane,
> /* Check whether this plane supports the fb pixel format. */
> ret = drm_plane_check_pixel_format(plane, fb->pixel_format);
> if (ret) {
> - char *format_name = drm_get_format_name(fb->pixel_format);
> - DRM_DEBUG_KMS("Invalid pixel format %s\n", format_name);
> + struct drm_format_name_buf format_name;
> + DRM_DEBUG_KMS("Invalid pixel format %s\n",
> + drm_get_format_name(fb->pixel_format,
> + &format_name));
> - kfree(format_name);
> goto out;
> }
>
> diff --git a/drivers/gpu/drm/hisilicon/kirin/kirin_drm_ade.c b/drivers/gpu/drm/hisilicon/kirin/kirin_drm_ade.c
> index 7e7a4d4..afc2b5d 100644
> --- a/drivers/gpu/drm/hisilicon/kirin/kirin_drm_ade.c
> +++ b/drivers/gpu/drm/hisilicon/kirin/kirin_drm_ade.c
> @@ -608,17 +608,16 @@ static void ade_rdma_set(void __iomem *base, struct drm_framebuffer *fb,
> u32 ch, u32 y, u32 in_h, u32 fmt)
> {
> struct drm_gem_cma_object *obj = drm_fb_cma_get_gem_obj(fb, 0);
> - char *format_name;
> + struct drm_format_name_buf format_name;
> u32 reg_ctrl, reg_addr, reg_size, reg_stride, reg_space, reg_en;
> u32 stride = fb->pitches[0];
> u32 addr = (u32)obj->paddr + y * stride;
>
> DRM_DEBUG_DRIVER("rdma%d: (y=%d, height=%d), stride=%d, paddr=0x%x\n",
> ch + 1, y, in_h, stride, (u32)obj->paddr);
> - format_name = drm_get_format_name(fb->pixel_format);
> DRM_DEBUG_DRIVER("addr=0x%x, fb:%dx%d, pixel_format=%d(%s)\n",
> - addr, fb->width, fb->height, fmt, format_name);
> + addr, fb->width, fb->height, fmt,
> + drm_get_format_name(fb->pixel_format, &format_name));
> - kfree(format_name);
>
> /* get reg offset */
> reg_ctrl = RD_CH_CTRL(ch);
> diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
> index 20638d2..670423e 100644
> --- a/drivers/gpu/drm/i915/i915_debugfs.c
> +++ b/drivers/gpu/drm/i915/i915_debugfs.c
> @@ -2971,7 +2971,7 @@ static void intel_plane_info(struct seq_file *m, struct intel_crtc *intel_crtc)
> for_each_intel_plane_on_crtc(dev, intel_crtc, intel_plane) {
> struct drm_plane_state *state;
> struct drm_plane *plane = &intel_plane->base;
> - char *format_name;
> + struct drm_format_name_buf format_name;
>
> if (!plane->state) {
> seq_puts(m, "plane->state is NULL!\n");
> @@ -2981,9 +2981,9 @@ static void intel_plane_info(struct seq_file *m, struct intel_crtc *intel_crtc)
> state = plane->state;
>
> if (state->fb) {
> - format_name = drm_get_format_name(state->fb->pixel_format);
> + drm_get_format_name(state->fb->pixel_format, &format_name);
> } else {
> - format_name = kstrdup("N/A", GFP_KERNEL);
> + sprintf(format_name.str, "N/A");
> }
>
> seq_printf(m, "\t--Plane id %d: type=%s, crtc_pos=%4dx%4d, crtc_size=%4dx%4d, src_pos=%d.%04ux%d.%04u, src_size=%d.%04ux%d.%04u, format=%s, rotation=%s\n",
> @@ -2999,10 +2999,8 @@ static void intel_plane_info(struct seq_file *m, struct intel_crtc *intel_crtc)
> ((state->src_w & 0xffff) * 15625) >> 10,
> (state->src_h >> 16),
> ((state->src_h & 0xffff) * 15625) >> 10,
> - format_name,
> + format_name.str,
> plane_rotation(state->rotation));
> -
> - kfree(format_name);
> }
> }
>
> diff --git a/drivers/gpu/drm/i915/intel_atomic_plane.c b/drivers/gpu/drm/i915/intel_atomic_plane.c
> index c762ae5..6c76e3d 100644
> --- a/drivers/gpu/drm/i915/intel_atomic_plane.c
> +++ b/drivers/gpu/drm/i915/intel_atomic_plane.c
> @@ -143,7 +143,7 @@ static int intel_plane_atomic_check(struct drm_plane *plane,
> crtc_state->base.enable ? crtc_state->pipe_src_h : 0;
>
> if (state->fb && drm_rotation_90_or_270(state->rotation)) {
> - char *format_name;
> + struct drm_format_name_buf format_name;
>
> if (!(state->fb->modifier[0] == I915_FORMAT_MOD_Y_TILED ||
> state->fb->modifier[0] == I915_FORMAT_MOD_Yf_TILED)) {
> @@ -159,9 +159,9 @@ static int intel_plane_atomic_check(struct drm_plane *plane,
> switch (state->fb->pixel_format) {
> case DRM_FORMAT_C8:
> case DRM_FORMAT_RGB565:
> - format_name = drm_get_format_name(state->fb->pixel_format);
> - DRM_DEBUG_KMS("Unsupported pixel format %s for 90/270!\n", format_name);
> + DRM_DEBUG_KMS("Unsupported pixel format %s for 90/270!\n",
> + drm_get_format_name(state->fb->pixel_format,
> + &format_name));
> - kfree(format_name);
> return -EINVAL;
>
> default:
> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> index 6f8f6ec..8209170 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -12871,7 +12871,7 @@ static void intel_dump_pipe_config(struct intel_crtc *crtc,
>
> DRM_DEBUG_KMS("planes on this crtc\n");
> list_for_each_entry(plane, &dev->mode_config.plane_list, head) {
> - char *format_name;
> + struct drm_format_name_buf format_name;
> intel_plane = to_intel_plane(plane);
> if (intel_plane->pipe != crtc->pipe)
> continue;
> @@ -12884,12 +12884,11 @@ static void intel_dump_pipe_config(struct intel_crtc *crtc,
> continue;
> }
>
> - format_name = drm_get_format_name(fb->pixel_format);
> -
> DRM_DEBUG_KMS("[PLANE:%d:%s] enabled",
> plane->base.id, plane->name);
> DRM_DEBUG_KMS("\tFB:%d, fb = %ux%u format = %s",
> - fb->base.id, fb->width, fb->height, format_name);
> + fb->base.id, fb->width, fb->height,
> + drm_get_format_name(fb->pixel_format, &format_name));
> DRM_DEBUG_KMS("\tscaler:%d src %dx%d+%d+%d dst %dx%d+%d+%d\n",
> state->scaler_id,
> state->base.src.x1 >> 16,
> @@ -12899,8 +12898,6 @@ static void intel_dump_pipe_config(struct intel_crtc *crtc,
> state->base.dst.x1, state->base.dst.y1,
> drm_rect_width(&state->base.dst),
> drm_rect_height(&state->base.dst));
> -
> - kfree(format_name);
> }
> }
>
> @@ -15749,7 +15746,7 @@ static int intel_framebuffer_init(struct drm_device *dev,
> unsigned int tiling = i915_gem_object_get_tiling(obj);
> int ret;
> u32 pitch_limit, stride_alignment;
> - char *format_name;
> + struct drm_format_name_buf format_name;
>
> WARN_ON(!mutex_is_locked(&dev->struct_mutex));
>
> @@ -15840,18 +15837,16 @@ static int intel_framebuffer_init(struct drm_device *dev,
> break;
> case DRM_FORMAT_XRGB1555:
> if (INTEL_INFO(dev)->gen > 3) {
> - format_name = drm_get_format_name(mode_cmd->pixel_format);
> - DRM_DEBUG("unsupported pixel format: %s\n", format_name);
> + DRM_DEBUG("unsupported pixel format: %s\n",
> + drm_get_format_name(mode_cmd->pixel_format, &format_name));
> - kfree(format_name);
> return -EINVAL;
> }
> break;
> case DRM_FORMAT_ABGR8888:
> if (!IS_VALLEYVIEW(dev_priv) && !IS_CHERRYVIEW(dev_priv) &&
> INTEL_INFO(dev)->gen < 9) {
> - format_name = drm_get_format_name(mode_cmd->pixel_format);
> - DRM_DEBUG("unsupported pixel format: %s\n", format_name);
> + DRM_DEBUG("unsupported pixel format: %s\n",
> + drm_get_format_name(mode_cmd->pixel_format, &format_name));
> - kfree(format_name);
> return -EINVAL;
> }
> break;
> @@ -15859,17 +15854,15 @@ static int intel_framebuffer_init(struct drm_device *dev,
> case DRM_FORMAT_XRGB2101010:
> case DRM_FORMAT_XBGR2101010:
> if (INTEL_INFO(dev)->gen < 4) {
> - format_name = drm_get_format_name(mode_cmd->pixel_format);
> - DRM_DEBUG("unsupported pixel format: %s\n", format_name);
> + DRM_DEBUG("unsupported pixel format: %s\n",
> + drm_get_format_name(mode_cmd->pixel_format, &format_name));
> - kfree(format_name);
> return -EINVAL;
> }
> break;
> case DRM_FORMAT_ABGR2101010:
> if (!IS_VALLEYVIEW(dev_priv) && !IS_CHERRYVIEW(dev_priv)) {
> - format_name = drm_get_format_name(mode_cmd->pixel_format);
> - DRM_DEBUG("unsupported pixel format: %s\n", format_name);
> + DRM_DEBUG("unsupported pixel format: %s\n",
> + drm_get_format_name(mode_cmd->pixel_format, &format_name));
> - kfree(format_name);
> return -EINVAL;
> }
> break;
> @@ -15878,16 +15871,14 @@ static int intel_framebuffer_init(struct drm_device *dev,
> case DRM_FORMAT_YVYU:
> case DRM_FORMAT_VYUY:
> if (INTEL_INFO(dev)->gen < 5) {
> - format_name = drm_get_format_name(mode_cmd->pixel_format);
> - DRM_DEBUG("unsupported pixel format: %s\n", format_name);
> + DRM_DEBUG("unsupported pixel format: %s\n",
> + drm_get_format_name(mode_cmd->pixel_format, &format_name));
> - kfree(format_name);
> return -EINVAL;
> }
> break;
> default:
> - format_name = drm_get_format_name(mode_cmd->pixel_format);
> - DRM_DEBUG("unsupported pixel format: %s\n", format_name);
> + DRM_DEBUG("unsupported pixel format: %s\n",
> + drm_get_format_name(mode_cmd->pixel_format, &format_name));
> - kfree(format_name);
> return -EINVAL;
> }
>
> diff --git a/drivers/gpu/drm/radeon/atombios_crtc.c b/drivers/gpu/drm/radeon/atombios_crtc.c
> index 74f99ba..05f4ebe 100644
> --- a/drivers/gpu/drm/radeon/atombios_crtc.c
> +++ b/drivers/gpu/drm/radeon/atombios_crtc.c
> @@ -1156,7 +1156,7 @@ static int dce4_crtc_do_set_base(struct drm_crtc *crtc,
> u32 tmp, viewport_w, viewport_h;
> int r;
> bool bypass_lut = false;
> - char *format_name;
> + struct drm_format_name_buf format_name;
>
> /* no fb bound */
> if (!atomic && !crtc->primary->fb) {
> @@ -1260,9 +1260,8 @@ static int dce4_crtc_do_set_base(struct drm_crtc *crtc,
> bypass_lut = true;
> break;
> default:
> - format_name = drm_get_format_name(target_fb->pixel_format);
> - DRM_ERROR("Unsupported screen format %s\n", format_name);
> + DRM_ERROR("Unsupported screen format %s\n",
> + drm_get_format_name(target_fb->pixel_format, &format_name));
> - kfree(format_name);
> return -EINVAL;
> }
>
> @@ -1473,7 +1472,7 @@ static int avivo_crtc_do_set_base(struct drm_crtc *crtc,
> u32 viewport_w, viewport_h;
> int r;
> bool bypass_lut = false;
> - char *format_name;
> + struct drm_format_name_buf format_name;
>
> /* no fb bound */
> if (!atomic && !crtc->primary->fb) {
> @@ -1563,9 +1562,8 @@ static int avivo_crtc_do_set_base(struct drm_crtc *crtc,
> bypass_lut = true;
> break;
> default:
> - format_name = drm_get_format_name(target_fb->pixel_format);
> - DRM_ERROR("Unsupported screen format %s\n", format_name);
> + DRM_ERROR("Unsupported screen format %s\n",
> + drm_get_format_name(target_fb->pixel_format, &format_name));
> - kfree(format_name);
> return -EINVAL;
> }
>
> diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c b/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c
> index c965514..e3f68cc 100644
> --- a/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c
> +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c
> @@ -985,8 +985,9 @@ static struct drm_framebuffer *vmw_kms_fb_create(struct drm_device *dev,
>
> info = drm_format_info(mode_cmd2->pixel_format);
> if (!info || !info->depth) {
> + struct drm_format_name_buf format_name;
> DRM_ERROR("Unsupported framebuffer format %s\n",
> - drm_get_format_name(mode_cmd2->pixel_format));
> + drm_get_format_name(mode_cmd2->pixel_format, &format_name));
> return ERR_PTR(-EINVAL);
> }
>
> --
> Cheers,
> Eric
>

2016-11-08 10:16:08

[permalink] [raw]

Subject: Re: [Intel-gfx] [PATCH v2] drm: move allocation out of drm_get_format_name()

On Mon, Nov 07, 2016 at 07:38:25PM +0200, Jani Nikula wrote:
> On Mon, 07 Nov 2016, Eric Engestrom <[email protected]> wrote:
> > On Monday, 2016-11-07 10:10:13 +0200, Jani Nikula wrote:
> >> On Mon, 07 Nov 2016, Eric Engestrom <[email protected]> wrote:
> >> > Fixes: 90844f00049e9f42573fd31d7c32e8fd31d3fd07
> >> >
> >> > drm: make drm_get_format_name thread-safe
> >> >
> >> > Signed-off-by: Eric Engestrom <[email protected]>
> >> > [danvet: Clarify that the returned pointer must be freed with
> >> > kfree().]
> >> > Signed-off-by: Daniel Vetter <[email protected]>
> >>
> >> The Fixes: format is:
> >>
> >> Fixes: 90844f00049e ("drm: make drm_get_format_name thread-safe")
> >>
> >> But is this a fix, really, or just an improvement? What exactly is the
> >> bug being fixed? The commit message is not sufficient.
> >
> > "The function's behaviour was changed in 90844f00049e, without changing
> > its signature, causing people to keep using it the old way without
> > realising they were now leaking memory.
> > Rob Clark also noticed it was also allocating GFP_KERNEL memory in
> > atomic contexts, breaking them.
> >
> > Instead of having to allocate GFP_ATOMIC memory and fixing the callers
> > to make them cleanup the memory afterwards, let's change the function's
> > signature by having the caller take care of the memory and passing it to
> > the function.
> > The new parameter is a single-field struct in order to enforce the size
> > of its buffer and help callers to correctly manage their memory."
> >
> > Does this sound good?
>
> It's fine; no need to go overboard. ;)

Can you pls resend with that and corrected Fixes and all the acks
collected?
-Daniel

>
> BR,
> Jani.
>
> >
> >> > @@ -54,6 +62,6 @@ int drm_format_horz_chroma_subsampling(uint32_t format);
> >> > int drm_format_vert_chroma_subsampling(uint32_t format);
> >> > int drm_format_plane_width(int width, uint32_t format, int plane);
> >> > int drm_format_plane_height(int height, uint32_t format, int plane);
> >> > -char *drm_get_format_name(uint32_t format) __malloc;
> >> > +char *drm_get_format_name(uint32_t format, struct drm_format_name_buf *buf);
> >>
> >> I wonder if it would be better to make that return "const char *". If
> >> the user really wants to look under the hood, there's buf->str. *shrug*
> >
> > Good idea, I'll do that in v3 with the proper commit msg and tags. It'll
> > have to wait another day though, -ENOTIME and all.
> >
> >>
> >> With the commit message improved,
> >>
> >> Reviewed-by: Jani Nikula <[email protected]>
> >
> > Cheers :)
> > Eric
>
> --
> Jani Nikula, Intel Open Source Technology Center
> _______________________________________________
> Intel-gfx mailing list
> [email protected]
> https://lists.freedesktop.org/mailman/listinfo/intel-gfx

--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch

2016-11-09 00:19:22

[permalink] [raw]

Subject: [PATCH v3] drm: move allocation out of drm_get_format_name()

The function's behaviour was changed in 90844f00049e, without changing
its signature, causing people to keep using it the old way without
realising they were now leaking memory.
Rob Clark also noticed it was also allocating GFP_KERNEL memory in
atomic contexts, breaking them.

Instead of having to allocate GFP_ATOMIC memory and fixing the callers
to make them cleanup the memory afterwards, let's change the function's
signature by having the caller take care of the memory and passing it to
the function.
The new parameter is a single-field struct in order to enforce the size
of its buffer and help callers to correctly manage their memory.

Fixes: 90844f00049e ("drm: make drm_get_format_name thread-safe")
Cc: Rob Clark <[email protected]>
Cc: Christian König <[email protected]>
Acked-by: Christian König <[email protected]>
Acked-by: Rob Clark <[email protected]>
Acked-by: Sinclair Yeh <[email protected]> (vmwgfx)
Reviewed-by: Jani Nikula <[email protected]>
Suggested-by: Ville Syrjälä <[email protected]>
Signed-off-by: Eric Engestrom <[email protected]>
---
v3 - fix "Fixes" tag, replace it with an actual commit message
- collect ack & r-b

v2 - use single-field struct instead of typedef to let the compiler
enforce the type (Christian König)
---
include/drm/drm_fourcc.h | 10 +++++-
drivers/gpu/drm/drm_fourcc.c | 14 +++------
drivers/gpu/drm/amd/amdgpu/dce_v10_0.c | 7 ++---
drivers/gpu/drm/amd/amdgpu/dce_v11_0.c | 7 ++---
drivers/gpu/drm/amd/amdgpu/dce_v6_0.c | 3 +-
drivers/gpu/drm/amd/amdgpu/dce_v8_0.c | 7 ++---
drivers/gpu/drm/drm_atomic.c | 7 +++--
drivers/gpu/drm/drm_crtc.c | 7 +++--
drivers/gpu/drm/drm_framebuffer.c | 7 +++--
drivers/gpu/drm/drm_modeset_helper.c | 7 +++--
drivers/gpu/drm/drm_plane.c | 7 +++--
drivers/gpu/drm/hisilicon/kirin/kirin_drm_ade.c | 7 ++---
drivers/gpu/drm/i915/i915_debugfs.c | 10 +++---
drivers/gpu/drm/i915/intel_atomic_plane.c | 8 ++---
drivers/gpu/drm/i915/intel_display.c | 41 ++++++++++---------------
drivers/gpu/drm/radeon/atombios_crtc.c | 14 ++++-----
drivers/gpu/drm/vmwgfx/vmwgfx_kms.c | 3 +-
17 files changed, 80 insertions(+), 86 deletions(-)

diff --git a/include/drm/drm_fourcc.h b/include/drm/drm_fourcc.h
index dc0aafa..4b03ca0 100644
--- a/include/drm/drm_fourcc.h
+++ b/include/drm/drm_fourcc.h
@@ -45,6 +45,14 @@ struct drm_format_info {
u8 vsub;
};

+/**
+ * struct drm_format_name_buf - name of a DRM format
+ * @str: string buffer containing the format name
+ */
+struct drm_format_name_buf {
+ char str[32];
+};
+
const struct drm_format_info *__drm_format_info(u32 format);
const struct drm_format_info *drm_format_info(u32 format);
uint32_t drm_mode_legacy_fb_format(uint32_t bpp, uint32_t depth);
@@ -54,6 +62,6 @@ int drm_format_horz_chroma_subsampling(uint32_t format);
int drm_format_vert_chroma_subsampling(uint32_t format);
int drm_format_plane_width(int width, uint32_t format, int plane);
int drm_format_plane_height(int height, uint32_t format, int plane);
-char *drm_get_format_name(uint32_t format) __malloc;
+char *drm_get_format_name(uint32_t format, struct drm_format_name_buf *buf);

#endif /* __DRM_FOURCC_H__ */
diff --git a/drivers/gpu/drm/drm_fourcc.c b/drivers/gpu/drm/drm_fourcc.c
index cbb8b77..99b0b60 100644
--- a/drivers/gpu/drm/drm_fourcc.c
+++ b/drivers/gpu/drm/drm_fourcc.c
@@ -79,17 +79,13 @@ uint32_t drm_mode_legacy_fb_format(uint32_t bpp, uint32_t depth)
EXPORT_SYMBOL(drm_mode_legacy_fb_format);

/**
- * drm_get_format_name - return a string for drm fourcc format
+ * drm_get_format_name - fill a string with a drm fourcc format's name
* @format: format to compute name of
+ * @buf: caller-supplied buffer
- *
- * Note that the buffer returned by this function is owned by the caller
- * and will need to be freed using kfree().
*/
-char *drm_get_format_name(uint32_t format)
+char *drm_get_format_name(uint32_t format, struct drm_format_name_buf *buf)
{
- char *buf = kmalloc(32, GFP_KERNEL);
-
- snprintf(buf, 32,
+ snprintf(buf->str, sizeof(buf->str),
"%c%c%c%c %s-endian (0x%08x)",
printable_char(format & 0xff),
printable_char((format >> 8) & 0xff),
@@ -98,7 +94,7 @@ char *drm_get_format_name(uint32_t format)
format & DRM_FORMAT_BIG_ENDIAN ? "big" : "little",
format);

- return buf;
+ return buf->str;
}
EXPORT_SYMBOL(drm_get_format_name);

diff --git a/drivers/gpu/drm/amd/amdgpu/dce_v10_0.c b/drivers/gpu/drm/amd/amdgpu/dce_v10_0.c
index 199d3f7..2924cdd 100644
--- a/drivers/gpu/drm/amd/amdgpu/dce_v10_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/dce_v10_0.c
@@ -2032,7 +2032,7 @@ static int dce_v10_0_crtc_do_set_base(struct drm_crtc *crtc,
u32 tmp, viewport_w, viewport_h;
int r;
bool bypass_lut = false;
- char *format_name;
+ struct drm_format_name_buf format_name;

/* no fb bound */
if (!atomic && !crtc->primary->fb) {
@@ -2144,9 +2144,8 @@ static int dce_v10_0_crtc_do_set_base(struct drm_crtc *crtc,
bypass_lut = true;
break;
default:
- format_name = drm_get_format_name(target_fb->pixel_format);
- DRM_ERROR("Unsupported screen format %s\n", format_name);
+ DRM_ERROR("Unsupported screen format %s\n",
+ drm_get_format_name(target_fb->pixel_format, &format_name));
- kfree(format_name);
return -EINVAL;
}

diff --git a/drivers/gpu/drm/amd/amdgpu/dce_v11_0.c b/drivers/gpu/drm/amd/amdgpu/dce_v11_0.c
index ecd000e..f0e3c5c 100644
--- a/drivers/gpu/drm/amd/amdgpu/dce_v11_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/dce_v11_0.c
@@ -2013,7 +2013,7 @@ static int dce_v11_0_crtc_do_set_base(struct drm_crtc *crtc,
u32 tmp, viewport_w, viewport_h;
int r;
bool bypass_lut = false;
- char *format_name;
+ struct drm_format_name_buf format_name;

/* no fb bound */
if (!atomic && !crtc->primary->fb) {
@@ -2125,9 +2125,8 @@ static int dce_v11_0_crtc_do_set_base(struct drm_crtc *crtc,
bypass_lut = true;
break;
default:
- format_name = drm_get_format_name(target_fb->pixel_format);
- DRM_ERROR("Unsupported screen format %s\n", format_name);
+ DRM_ERROR("Unsupported screen format %s\n",
+ drm_get_format_name(target_fb->pixel_format, &format_name));
- kfree(format_name);
return -EINVAL;
}

diff --git a/drivers/gpu/drm/amd/amdgpu/dce_v6_0.c b/drivers/gpu/drm/amd/amdgpu/dce_v6_0.c
index 44547f9..5c6b82f 100644
--- a/drivers/gpu/drm/amd/amdgpu/dce_v6_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/dce_v6_0.c
@@ -1456,6 +1456,7 @@ static int dce_v6_0_crtc_do_set_base(struct drm_crtc *crtc,
u32 viewport_w, viewport_h;
int r;
bool bypass_lut = false;
+ struct drm_format_name_buf format_name;

/* no fb bound */
if (!atomic && !crtc->primary->fb) {
@@ -1559,7 +1560,7 @@ static int dce_v6_0_crtc_do_set_base(struct drm_crtc *crtc,
break;
default:
DRM_ERROR("Unsupported screen format %s\n",
- drm_get_format_name(target_fb->pixel_format));
+ drm_get_format_name(target_fb->pixel_format, &format_name));
return -EINVAL;
}

diff --git a/drivers/gpu/drm/amd/amdgpu/dce_v8_0.c b/drivers/gpu/drm/amd/amdgpu/dce_v8_0.c
index 979aedf..5aef19d 100644
--- a/drivers/gpu/drm/amd/amdgpu/dce_v8_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/dce_v8_0.c
@@ -1910,7 +1910,7 @@ static int dce_v8_0_crtc_do_set_base(struct drm_crtc *crtc,
u32 viewport_w, viewport_h;
int r;
bool bypass_lut = false;
- char *format_name;
+ struct drm_format_name_buf format_name;

/* no fb bound */
if (!atomic && !crtc->primary->fb) {
@@ -2015,9 +2015,8 @@ static int dce_v8_0_crtc_do_set_base(struct drm_crtc *crtc,
bypass_lut = true;
break;
default:
- format_name = drm_get_format_name(target_fb->pixel_format);
- DRM_ERROR("Unsupported screen format %s\n", format_name);
+ DRM_ERROR("Unsupported screen format %s\n",
+ drm_get_format_name(target_fb->pixel_format, &format_name));
- kfree(format_name);
return -EINVAL;
}

diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c
index c32fb3c..f29d3c5 100644
--- a/drivers/gpu/drm/drm_atomic.c
+++ b/drivers/gpu/drm/drm_atomic.c
@@ -835,9 +835,10 @@ static int drm_atomic_plane_check(struct drm_plane *plane,
/* Check whether this plane supports the fb pixel format. */
ret = drm_plane_check_pixel_format(plane, state->fb->pixel_format);
if (ret) {
- char *format_name = drm_get_format_name(state->fb->pixel_format);
- DRM_DEBUG_ATOMIC("Invalid pixel format %s\n", format_name);
+ struct drm_format_name_buf format_name;
+ DRM_DEBUG_ATOMIC("Invalid pixel format %s\n",
+ drm_get_format_name(state->fb->pixel_format,
+ &format_name));
- kfree(format_name);
return ret;
}

diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
index 13441e2..08ac216 100644
--- a/drivers/gpu/drm/drm_crtc.c
+++ b/drivers/gpu/drm/drm_crtc.c
@@ -827,9 +827,10 @@ int drm_mode_setcrtc(struct drm_device *dev, void *data,
ret = drm_plane_check_pixel_format(crtc->primary,
fb->pixel_format);
if (ret) {
- char *format_name = drm_get_format_name(fb->pixel_format);
- DRM_DEBUG_KMS("Invalid pixel format %s\n", format_name);
+ struct drm_format_name_buf format_name;
+ DRM_DEBUG_KMS("Invalid pixel format %s\n",
+ drm_get_format_name(fb->pixel_format,
+ &format_name));
- kfree(format_name);
goto out;
}
}
diff --git a/drivers/gpu/drm/drm_framebuffer.c b/drivers/gpu/drm/drm_framebuffer.c
index 49fd7db..df6b180 100644
--- a/drivers/gpu/drm/drm_framebuffer.c
+++ b/drivers/gpu/drm/drm_framebuffer.c
@@ -133,9 +133,10 @@ static int framebuffer_check(const struct drm_mode_fb_cmd2 *r)

info = __drm_format_info(r->pixel_format & ~DRM_FORMAT_BIG_ENDIAN);
if (!info) {
- char *format_name = drm_get_format_name(r->pixel_format);
- DRM_DEBUG_KMS("bad framebuffer format %s\n", format_name);
+ struct drm_format_name_buf format_name;
+ DRM_DEBUG_KMS("bad framebuffer format %s\n",
+ drm_get_format_name(r->pixel_format,
+ &format_name));
- kfree(format_name);
return -EINVAL;
}

diff --git a/drivers/gpu/drm/drm_modeset_helper.c b/drivers/gpu/drm/drm_modeset_helper.c
index 2544dfe..2f452b3 100644
--- a/drivers/gpu/drm/drm_modeset_helper.c
+++ b/drivers/gpu/drm/drm_modeset_helper.c
@@ -75,10 +75,11 @@ void drm_helper_mode_fill_fb_struct(struct drm_framebuffer *fb,

info = drm_format_info(mode_cmd->pixel_format);
if (!info || !info->depth) {
- char *format_name = drm_get_format_name(mode_cmd->pixel_format);
+ struct drm_format_name_buf format_name;

- DRM_DEBUG_KMS("non-RGB pixel format %s\n", format_name);
+ DRM_DEBUG_KMS("non-RGB pixel format %s\n",
+ drm_get_format_name(mode_cmd->pixel_format,
+ &format_name));
- kfree(format_name);

fb->depth = 0;
fb->bits_per_pixel = 0;
diff --git a/drivers/gpu/drm/drm_plane.c b/drivers/gpu/drm/drm_plane.c
index 249c0ae..2ba0c22 100644
--- a/drivers/gpu/drm/drm_plane.c
+++ b/drivers/gpu/drm/drm_plane.c
@@ -479,9 +479,10 @@ static int __setplane_internal(struct drm_plane *plane,
/* Check whether this plane supports the fb pixel format. */
ret = drm_plane_check_pixel_format(plane, fb->pixel_format);
if (ret) {
- char *format_name = drm_get_format_name(fb->pixel_format);
- DRM_DEBUG_KMS("Invalid pixel format %s\n", format_name);
+ struct drm_format_name_buf format_name;
+ DRM_DEBUG_KMS("Invalid pixel format %s\n",
+ drm_get_format_name(fb->pixel_format,
+ &format_name));
- kfree(format_name);
goto out;
}

diff --git a/drivers/gpu/drm/hisilicon/kirin/kirin_drm_ade.c b/drivers/gpu/drm/hisilicon/kirin/kirin_drm_ade.c
index 7e7a4d4..afc2b5d 100644
--- a/drivers/gpu/drm/hisilicon/kirin/kirin_drm_ade.c
+++ b/drivers/gpu/drm/hisilicon/kirin/kirin_drm_ade.c
@@ -608,17 +608,16 @@ static void ade_rdma_set(void __iomem *base, struct drm_framebuffer *fb,
u32 ch, u32 y, u32 in_h, u32 fmt)
{
struct drm_gem_cma_object *obj = drm_fb_cma_get_gem_obj(fb, 0);
- char *format_name;
+ struct drm_format_name_buf format_name;
u32 reg_ctrl, reg_addr, reg_size, reg_stride, reg_space, reg_en;
u32 stride = fb->pitches[0];
u32 addr = (u32)obj->paddr + y * stride;

DRM_DEBUG_DRIVER("rdma%d: (y=%d, height=%d), stride=%d, paddr=0x%x\n",
ch + 1, y, in_h, stride, (u32)obj->paddr);
- format_name = drm_get_format_name(fb->pixel_format);
DRM_DEBUG_DRIVER("addr=0x%x, fb:%dx%d, pixel_format=%d(%s)\n",
- addr, fb->width, fb->height, fmt, format_name);
+ addr, fb->width, fb->height, fmt,
+ drm_get_format_name(fb->pixel_format, &format_name));
- kfree(format_name);

/* get reg offset */
reg_ctrl = RD_CH_CTRL(ch);
diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
index 20638d2..670423e 100644
--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -2971,7 +2971,7 @@ static void intel_plane_info(struct seq_file *m, struct intel_crtc *intel_crtc)
for_each_intel_plane_on_crtc(dev, intel_crtc, intel_plane) {
struct drm_plane_state *state;
struct drm_plane *plane = &intel_plane->base;
- char *format_name;
+ struct drm_format_name_buf format_name;

if (!plane->state) {
seq_puts(m, "plane->state is NULL!\n");
@@ -2981,9 +2981,9 @@ static void intel_plane_info(struct seq_file *m, struct intel_crtc *intel_crtc)
state = plane->state;

if (state->fb) {
- format_name = drm_get_format_name(state->fb->pixel_format);
+ drm_get_format_name(state->fb->pixel_format, &format_name);
} else {
- format_name = kstrdup("N/A", GFP_KERNEL);
+ sprintf(format_name.str, "N/A");
}

seq_printf(m, "\t--Plane id %d: type=%s, crtc_pos=%4dx%4d, crtc_size=%4dx%4d, src_pos=%d.%04ux%d.%04u, src_size=%d.%04ux%d.%04u, format=%s, rotation=%s\n",
@@ -2999,10 +2999,8 @@ static void intel_plane_info(struct seq_file *m, struct intel_crtc *intel_crtc)
((state->src_w & 0xffff) * 15625) >> 10,
(state->src_h >> 16),
((state->src_h & 0xffff) * 15625) >> 10,
- format_name,
+ format_name.str,
plane_rotation(state->rotation));
-
- kfree(format_name);
}
}

diff --git a/drivers/gpu/drm/i915/intel_atomic_plane.c b/drivers/gpu/drm/i915/intel_atomic_plane.c
index c762ae5..6c76e3d 100644
--- a/drivers/gpu/drm/i915/intel_atomic_plane.c
+++ b/drivers/gpu/drm/i915/intel_atomic_plane.c
@@ -143,7 +143,7 @@ static int intel_plane_atomic_check(struct drm_plane *plane,
crtc_state->base.enable ? crtc_state->pipe_src_h : 0;

if (state->fb && drm_rotation_90_or_270(state->rotation)) {
- char *format_name;
+ struct drm_format_name_buf format_name;

if (!(state->fb->modifier[0] == I915_FORMAT_MOD_Y_TILED ||
state->fb->modifier[0] == I915_FORMAT_MOD_Yf_TILED)) {
@@ -159,9 +159,9 @@ static int intel_plane_atomic_check(struct drm_plane *plane,
switch (state->fb->pixel_format) {
case DRM_FORMAT_C8:
case DRM_FORMAT_RGB565:
- format_name = drm_get_format_name(state->fb->pixel_format);
- DRM_DEBUG_KMS("Unsupported pixel format %s for 90/270!\n", format_name);
+ DRM_DEBUG_KMS("Unsupported pixel format %s for 90/270!\n",
+ drm_get_format_name(state->fb->pixel_format,
+ &format_name));
- kfree(format_name);
return -EINVAL;

default:
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 6f8f6ec..8209170 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -12871,7 +12871,7 @@ static void intel_dump_pipe_config(struct intel_crtc *crtc,

DRM_DEBUG_KMS("planes on this crtc\n");
list_for_each_entry(plane, &dev->mode_config.plane_list, head) {
- char *format_name;
+ struct drm_format_name_buf format_name;
intel_plane = to_intel_plane(plane);
if (intel_plane->pipe != crtc->pipe)
continue;
@@ -12884,12 +12884,11 @@ static void intel_dump_pipe_config(struct intel_crtc *crtc,
continue;
}

- format_name = drm_get_format_name(fb->pixel_format);
-
DRM_DEBUG_KMS("[PLANE:%d:%s] enabled",
plane->base.id, plane->name);
DRM_DEBUG_KMS("\tFB:%d, fb = %ux%u format = %s",
- fb->base.id, fb->width, fb->height, format_name);
+ fb->base.id, fb->width, fb->height,
+ drm_get_format_name(fb->pixel_format, &format_name));
DRM_DEBUG_KMS("\tscaler:%d src %dx%d+%d+%d dst %dx%d+%d+%d\n",
state->scaler_id,
state->base.src.x1 >> 16,
@@ -12899,8 +12898,6 @@ static void intel_dump_pipe_config(struct intel_crtc *crtc,
state->base.dst.x1, state->base.dst.y1,
drm_rect_width(&state->base.dst),
drm_rect_height(&state->base.dst));
-
- kfree(format_name);
}
}

@@ -15749,7 +15746,7 @@ static int intel_framebuffer_init(struct drm_device *dev,
unsigned int tiling = i915_gem_object_get_tiling(obj);
int ret;
u32 pitch_limit, stride_alignment;
- char *format_name;
+ struct drm_format_name_buf format_name;

WARN_ON(!mutex_is_locked(&dev->struct_mutex));

@@ -15840,18 +15837,16 @@ static int intel_framebuffer_init(struct drm_device *dev,
break;
case DRM_FORMAT_XRGB1555:
if (INTEL_INFO(dev)->gen > 3) {
- format_name = drm_get_format_name(mode_cmd->pixel_format);
- DRM_DEBUG("unsupported pixel format: %s\n", format_name);
+ DRM_DEBUG("unsupported pixel format: %s\n",
+ drm_get_format_name(mode_cmd->pixel_format, &format_name));
- kfree(format_name);
return -EINVAL;
}
break;
case DRM_FORMAT_ABGR8888:
if (!IS_VALLEYVIEW(dev_priv) && !IS_CHERRYVIEW(dev_priv) &&
INTEL_INFO(dev)->gen < 9) {
- format_name = drm_get_format_name(mode_cmd->pixel_format);
- DRM_DEBUG("unsupported pixel format: %s\n", format_name);
+ DRM_DEBUG("unsupported pixel format: %s\n",
+ drm_get_format_name(mode_cmd->pixel_format, &format_name));
- kfree(format_name);
return -EINVAL;
}
break;
@@ -15859,17 +15854,15 @@ static int intel_framebuffer_init(struct drm_device *dev,
case DRM_FORMAT_XRGB2101010:
case DRM_FORMAT_XBGR2101010:
if (INTEL_INFO(dev)->gen < 4) {
- format_name = drm_get_format_name(mode_cmd->pixel_format);
- DRM_DEBUG("unsupported pixel format: %s\n", format_name);
+ DRM_DEBUG("unsupported pixel format: %s\n",
+ drm_get_format_name(mode_cmd->pixel_format, &format_name));
- kfree(format_name);
return -EINVAL;
}
break;
case DRM_FORMAT_ABGR2101010:
if (!IS_VALLEYVIEW(dev_priv) && !IS_CHERRYVIEW(dev_priv)) {
- format_name = drm_get_format_name(mode_cmd->pixel_format);
- DRM_DEBUG("unsupported pixel format: %s\n", format_name);
+ DRM_DEBUG("unsupported pixel format: %s\n",
+ drm_get_format_name(mode_cmd->pixel_format, &format_name));
- kfree(format_name);
return -EINVAL;
}
break;
@@ -15878,16 +15871,14 @@ static int intel_framebuffer_init(struct drm_device *dev,
case DRM_FORMAT_YVYU:
case DRM_FORMAT_VYUY:
if (INTEL_INFO(dev)->gen < 5) {
- format_name = drm_get_format_name(mode_cmd->pixel_format);
- DRM_DEBUG("unsupported pixel format: %s\n", format_name);
+ DRM_DEBUG("unsupported pixel format: %s\n",
+ drm_get_format_name(mode_cmd->pixel_format, &format_name));
- kfree(format_name);
return -EINVAL;
}
break;
default:
- format_name = drm_get_format_name(mode_cmd->pixel_format);
- DRM_DEBUG("unsupported pixel format: %s\n", format_name);
+ DRM_DEBUG("unsupported pixel format: %s\n",
+ drm_get_format_name(mode_cmd->pixel_format, &format_name));
- kfree(format_name);
return -EINVAL;
}

diff --git a/drivers/gpu/drm/radeon/atombios_crtc.c b/drivers/gpu/drm/radeon/atombios_crtc.c
index 74f99ba..05f4ebe 100644
--- a/drivers/gpu/drm/radeon/atombios_crtc.c
+++ b/drivers/gpu/drm/radeon/atombios_crtc.c
@@ -1156,7 +1156,7 @@ static int dce4_crtc_do_set_base(struct drm_crtc *crtc,
u32 tmp, viewport_w, viewport_h;
int r;
bool bypass_lut = false;
- char *format_name;
+ struct drm_format_name_buf format_name;

/* no fb bound */
if (!atomic && !crtc->primary->fb) {
@@ -1260,9 +1260,8 @@ static int dce4_crtc_do_set_base(struct drm_crtc *crtc,
bypass_lut = true;
break;
default:
- format_name = drm_get_format_name(target_fb->pixel_format);
- DRM_ERROR("Unsupported screen format %s\n", format_name);
+ DRM_ERROR("Unsupported screen format %s\n",
+ drm_get_format_name(target_fb->pixel_format, &format_name));
- kfree(format_name);
return -EINVAL;
}

@@ -1473,7 +1472,7 @@ static int avivo_crtc_do_set_base(struct drm_crtc *crtc,
u32 viewport_w, viewport_h;
int r;
bool bypass_lut = false;
- char *format_name;
+ struct drm_format_name_buf format_name;

/* no fb bound */
if (!atomic && !crtc->primary->fb) {
@@ -1563,9 +1562,8 @@ static int avivo_crtc_do_set_base(struct drm_crtc *crtc,
bypass_lut = true;
break;
default:
- format_name = drm_get_format_name(target_fb->pixel_format);
- DRM_ERROR("Unsupported screen format %s\n", format_name);
+ DRM_ERROR("Unsupported screen format %s\n",
+ drm_get_format_name(target_fb->pixel_format, &format_name));
- kfree(format_name);
return -EINVAL;
}

diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c b/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c
index c965514..e3f68cc 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c
@@ -985,8 +985,9 @@ static struct drm_framebuffer *vmw_kms_fb_create(struct drm_device *dev,

info = drm_format_info(mode_cmd2->pixel_format);
if (!info || !info->depth) {
+ struct drm_format_name_buf format_name;
DRM_ERROR("Unsupported framebuffer format %s\n",
- drm_get_format_name(mode_cmd2->pixel_format));
+ drm_get_format_name(mode_cmd2->pixel_format, &format_name));
return ERR_PTR(-EINVAL);
}

--
Cheers,
Eric

2016-11-09 01:09:24

[permalink] [raw]

Subject: Re: [Intel-gfx] [PATCH v3] drm: move allocation out of drm_get_format_name()

On Wed, Nov 09, 2016 at 12:17:52AM +0000, Eric Engestrom wrote:
> The function's behaviour was changed in 90844f00049e, without changing
> its signature, causing people to keep using it the old way without
> realising they were now leaking memory.
> Rob Clark also noticed it was also allocating GFP_KERNEL memory in
> atomic contexts, breaking them.
>
> Instead of having to allocate GFP_ATOMIC memory and fixing the callers
> to make them cleanup the memory afterwards, let's change the function's
> signature by having the caller take care of the memory and passing it to
> the function.
> The new parameter is a single-field struct in order to enforce the size
> of its buffer and help callers to correctly manage their memory.
>
> Fixes: 90844f00049e ("drm: make drm_get_format_name thread-safe")
> Cc: Rob Clark <[email protected]>
> Cc: Christian K?nig <[email protected]>
> Acked-by: Christian K?nig <[email protected]>
> Acked-by: Rob Clark <[email protected]>
> Acked-by: Sinclair Yeh <[email protected]> (vmwgfx)
> Reviewed-by: Jani Nikula <[email protected]>
> Suggested-by: Ville Syrj?l? <[email protected]>
> Signed-off-by: Eric Engestrom <[email protected]>
> ---
> v3 - fix "Fixes" tag, replace it with an actual commit message
> - collect ack & r-b
>
> v2 - use single-field struct instead of typedef to let the compiler
> enforce the type (Christian K?nig)

Applied to drm-misc, thanks.
-Daniel

> ---
> include/drm/drm_fourcc.h | 10 +++++-
> drivers/gpu/drm/drm_fourcc.c | 14 +++------
> drivers/gpu/drm/amd/amdgpu/dce_v10_0.c | 7 ++---
> drivers/gpu/drm/amd/amdgpu/dce_v11_0.c | 7 ++---
> drivers/gpu/drm/amd/amdgpu/dce_v6_0.c | 3 +-
> drivers/gpu/drm/amd/amdgpu/dce_v8_0.c | 7 ++---
> drivers/gpu/drm/drm_atomic.c | 7 +++--
> drivers/gpu/drm/drm_crtc.c | 7 +++--
> drivers/gpu/drm/drm_framebuffer.c | 7 +++--
> drivers/gpu/drm/drm_modeset_helper.c | 7 +++--
> drivers/gpu/drm/drm_plane.c | 7 +++--
> drivers/gpu/drm/hisilicon/kirin/kirin_drm_ade.c | 7 ++---
> drivers/gpu/drm/i915/i915_debugfs.c | 10 +++---
> drivers/gpu/drm/i915/intel_atomic_plane.c | 8 ++---
> drivers/gpu/drm/i915/intel_display.c | 41 ++++++++++---------------
> drivers/gpu/drm/radeon/atombios_crtc.c | 14 ++++-----
> drivers/gpu/drm/vmwgfx/vmwgfx_kms.c | 3 +-
> 17 files changed, 80 insertions(+), 86 deletions(-)
>
> diff --git a/include/drm/drm_fourcc.h b/include/drm/drm_fourcc.h
> index dc0aafa..4b03ca0 100644
> --- a/include/drm/drm_fourcc.h
> +++ b/include/drm/drm_fourcc.h
> @@ -45,6 +45,14 @@ struct drm_format_info {
> u8 vsub;
> };
>
> +/**
> + * struct drm_format_name_buf - name of a DRM format
> + * @str: string buffer containing the format name
> + */
> +struct drm_format_name_buf {
> + char str[32];
> +};
> +
> const struct drm_format_info *__drm_format_info(u32 format);
> const struct drm_format_info *drm_format_info(u32 format);
> uint32_t drm_mode_legacy_fb_format(uint32_t bpp, uint32_t depth);
> @@ -54,6 +62,6 @@ int drm_format_horz_chroma_subsampling(uint32_t format);
> int drm_format_vert_chroma_subsampling(uint32_t format);
> int drm_format_plane_width(int width, uint32_t format, int plane);
> int drm_format_plane_height(int height, uint32_t format, int plane);
> -char *drm_get_format_name(uint32_t format) __malloc;
> +char *drm_get_format_name(uint32_t format, struct drm_format_name_buf *buf);
>
> #endif /* __DRM_FOURCC_H__ */
> diff --git a/drivers/gpu/drm/drm_fourcc.c b/drivers/gpu/drm/drm_fourcc.c
> index cbb8b77..99b0b60 100644
> --- a/drivers/gpu/drm/drm_fourcc.c
> +++ b/drivers/gpu/drm/drm_fourcc.c
> @@ -79,17 +79,13 @@ uint32_t drm_mode_legacy_fb_format(uint32_t bpp, uint32_t depth)
> EXPORT_SYMBOL(drm_mode_legacy_fb_format);
>
> /**
> - * drm_get_format_name - return a string for drm fourcc format
> + * drm_get_format_name - fill a string with a drm fourcc format's name
> * @format: format to compute name of
> + * @buf: caller-supplied buffer
> - *
> - * Note that the buffer returned by this function is owned by the caller
> - * and will need to be freed using kfree().
> */
> -char *drm_get_format_name(uint32_t format)
> +char *drm_get_format_name(uint32_t format, struct drm_format_name_buf *buf)
> {
> - char *buf = kmalloc(32, GFP_KERNEL);
> -
> - snprintf(buf, 32,
> + snprintf(buf->str, sizeof(buf->str),
> "%c%c%c%c %s-endian (0x%08x)",
> printable_char(format & 0xff),
> printable_char((format >> 8) & 0xff),
> @@ -98,7 +94,7 @@ char *drm_get_format_name(uint32_t format)
> format & DRM_FORMAT_BIG_ENDIAN ? "big" : "little",
> format);
>
> - return buf;
> + return buf->str;
> }
> EXPORT_SYMBOL(drm_get_format_name);
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/dce_v10_0.c b/drivers/gpu/drm/amd/amdgpu/dce_v10_0.c
> index 199d3f7..2924cdd 100644
> --- a/drivers/gpu/drm/amd/amdgpu/dce_v10_0.c
> +++ b/drivers/gpu/drm/amd/amdgpu/dce_v10_0.c
> @@ -2032,7 +2032,7 @@ static int dce_v10_0_crtc_do_set_base(struct drm_crtc *crtc,
> u32 tmp, viewport_w, viewport_h;
> int r;
> bool bypass_lut = false;
> - char *format_name;
> + struct drm_format_name_buf format_name;
>
> /* no fb bound */
> if (!atomic && !crtc->primary->fb) {
> @@ -2144,9 +2144,8 @@ static int dce_v10_0_crtc_do_set_base(struct drm_crtc *crtc,
> bypass_lut = true;
> break;
> default:
> - format_name = drm_get_format_name(target_fb->pixel_format);
> - DRM_ERROR("Unsupported screen format %s\n", format_name);
> + DRM_ERROR("Unsupported screen format %s\n",
> + drm_get_format_name(target_fb->pixel_format, &format_name));
> - kfree(format_name);
> return -EINVAL;
> }
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/dce_v11_0.c b/drivers/gpu/drm/amd/amdgpu/dce_v11_0.c
> index ecd000e..f0e3c5c 100644
> --- a/drivers/gpu/drm/amd/amdgpu/dce_v11_0.c
> +++ b/drivers/gpu/drm/amd/amdgpu/dce_v11_0.c
> @@ -2013,7 +2013,7 @@ static int dce_v11_0_crtc_do_set_base(struct drm_crtc *crtc,
> u32 tmp, viewport_w, viewport_h;
> int r;
> bool bypass_lut = false;
> - char *format_name;
> + struct drm_format_name_buf format_name;
>
> /* no fb bound */
> if (!atomic && !crtc->primary->fb) {
> @@ -2125,9 +2125,8 @@ static int dce_v11_0_crtc_do_set_base(struct drm_crtc *crtc,
> bypass_lut = true;
> break;
> default:
> - format_name = drm_get_format_name(target_fb->pixel_format);
> - DRM_ERROR("Unsupported screen format %s\n", format_name);
> + DRM_ERROR("Unsupported screen format %s\n",
> + drm_get_format_name(target_fb->pixel_format, &format_name));
> - kfree(format_name);
> return -EINVAL;
> }
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/dce_v6_0.c b/drivers/gpu/drm/amd/amdgpu/dce_v6_0.c
> index 44547f9..5c6b82f 100644
> --- a/drivers/gpu/drm/amd/amdgpu/dce_v6_0.c
> +++ b/drivers/gpu/drm/amd/amdgpu/dce_v6_0.c
> @@ -1456,6 +1456,7 @@ static int dce_v6_0_crtc_do_set_base(struct drm_crtc *crtc,
> u32 viewport_w, viewport_h;
> int r;
> bool bypass_lut = false;
> + struct drm_format_name_buf format_name;
>
> /* no fb bound */
> if (!atomic && !crtc->primary->fb) {
> @@ -1559,7 +1560,7 @@ static int dce_v6_0_crtc_do_set_base(struct drm_crtc *crtc,
> break;
> default:
> DRM_ERROR("Unsupported screen format %s\n",
> - drm_get_format_name(target_fb->pixel_format));
> + drm_get_format_name(target_fb->pixel_format, &format_name));
> return -EINVAL;
> }
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/dce_v8_0.c b/drivers/gpu/drm/amd/amdgpu/dce_v8_0.c
> index 979aedf..5aef19d 100644
> --- a/drivers/gpu/drm/amd/amdgpu/dce_v8_0.c
> +++ b/drivers/gpu/drm/amd/amdgpu/dce_v8_0.c
> @@ -1910,7 +1910,7 @@ static int dce_v8_0_crtc_do_set_base(struct drm_crtc *crtc,
> u32 viewport_w, viewport_h;
> int r;
> bool bypass_lut = false;
> - char *format_name;
> + struct drm_format_name_buf format_name;
>
> /* no fb bound */
> if (!atomic && !crtc->primary->fb) {
> @@ -2015,9 +2015,8 @@ static int dce_v8_0_crtc_do_set_base(struct drm_crtc *crtc,
> bypass_lut = true;
> break;
> default:
> - format_name = drm_get_format_name(target_fb->pixel_format);
> - DRM_ERROR("Unsupported screen format %s\n", format_name);
> + DRM_ERROR("Unsupported screen format %s\n",
> + drm_get_format_name(target_fb->pixel_format, &format_name));
> - kfree(format_name);
> return -EINVAL;
> }
>
> diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c
> index c32fb3c..f29d3c5 100644
> --- a/drivers/gpu/drm/drm_atomic.c
> +++ b/drivers/gpu/drm/drm_atomic.c
> @@ -835,9 +835,10 @@ static int drm_atomic_plane_check(struct drm_plane *plane,
> /* Check whether this plane supports the fb pixel format. */
> ret = drm_plane_check_pixel_format(plane, state->fb->pixel_format);
> if (ret) {
> - char *format_name = drm_get_format_name(state->fb->pixel_format);
> - DRM_DEBUG_ATOMIC("Invalid pixel format %s\n", format_name);
> + struct drm_format_name_buf format_name;
> + DRM_DEBUG_ATOMIC("Invalid pixel format %s\n",
> + drm_get_format_name(state->fb->pixel_format,
> + &format_name));
> - kfree(format_name);
> return ret;
> }
>
> diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
> index 13441e2..08ac216 100644
> --- a/drivers/gpu/drm/drm_crtc.c
> +++ b/drivers/gpu/drm/drm_crtc.c
> @@ -827,9 +827,10 @@ int drm_mode_setcrtc(struct drm_device *dev, void *data,
> ret = drm_plane_check_pixel_format(crtc->primary,
> fb->pixel_format);
> if (ret) {
> - char *format_name = drm_get_format_name(fb->pixel_format);
> - DRM_DEBUG_KMS("Invalid pixel format %s\n", format_name);
> + struct drm_format_name_buf format_name;
> + DRM_DEBUG_KMS("Invalid pixel format %s\n",
> + drm_get_format_name(fb->pixel_format,
> + &format_name));
> - kfree(format_name);
> goto out;
> }
> }
> diff --git a/drivers/gpu/drm/drm_framebuffer.c b/drivers/gpu/drm/drm_framebuffer.c
> index 49fd7db..df6b180 100644
> --- a/drivers/gpu/drm/drm_framebuffer.c
> +++ b/drivers/gpu/drm/drm_framebuffer.c
> @@ -133,9 +133,10 @@ static int framebuffer_check(const struct drm_mode_fb_cmd2 *r)
>
> info = __drm_format_info(r->pixel_format & ~DRM_FORMAT_BIG_ENDIAN);
> if (!info) {
> - char *format_name = drm_get_format_name(r->pixel_format);
> - DRM_DEBUG_KMS("bad framebuffer format %s\n", format_name);
> + struct drm_format_name_buf format_name;
> + DRM_DEBUG_KMS("bad framebuffer format %s\n",
> + drm_get_format_name(r->pixel_format,
> + &format_name));
> - kfree(format_name);
> return -EINVAL;
> }
>
> diff --git a/drivers/gpu/drm/drm_modeset_helper.c b/drivers/gpu/drm/drm_modeset_helper.c
> index 2544dfe..2f452b3 100644
> --- a/drivers/gpu/drm/drm_modeset_helper.c
> +++ b/drivers/gpu/drm/drm_modeset_helper.c
> @@ -75,10 +75,11 @@ void drm_helper_mode_fill_fb_struct(struct drm_framebuffer *fb,
>
> info = drm_format_info(mode_cmd->pixel_format);
> if (!info || !info->depth) {
> - char *format_name = drm_get_format_name(mode_cmd->pixel_format);
> + struct drm_format_name_buf format_name;
>
> - DRM_DEBUG_KMS("non-RGB pixel format %s\n", format_name);
> + DRM_DEBUG_KMS("non-RGB pixel format %s\n",
> + drm_get_format_name(mode_cmd->pixel_format,
> + &format_name));
> - kfree(format_name);
>
> fb->depth = 0;
> fb->bits_per_pixel = 0;
> diff --git a/drivers/gpu/drm/drm_plane.c b/drivers/gpu/drm/drm_plane.c
> index 249c0ae..2ba0c22 100644
> --- a/drivers/gpu/drm/drm_plane.c
> +++ b/drivers/gpu/drm/drm_plane.c
> @@ -479,9 +479,10 @@ static int __setplane_internal(struct drm_plane *plane,
> /* Check whether this plane supports the fb pixel format. */
> ret = drm_plane_check_pixel_format(plane, fb->pixel_format);
> if (ret) {
> - char *format_name = drm_get_format_name(fb->pixel_format);
> - DRM_DEBUG_KMS("Invalid pixel format %s\n", format_name);
> + struct drm_format_name_buf format_name;
> + DRM_DEBUG_KMS("Invalid pixel format %s\n",
> + drm_get_format_name(fb->pixel_format,
> + &format_name));
> - kfree(format_name);
> goto out;
> }
>
> diff --git a/drivers/gpu/drm/hisilicon/kirin/kirin_drm_ade.c b/drivers/gpu/drm/hisilicon/kirin/kirin_drm_ade.c
> index 7e7a4d4..afc2b5d 100644
> --- a/drivers/gpu/drm/hisilicon/kirin/kirin_drm_ade.c
> +++ b/drivers/gpu/drm/hisilicon/kirin/kirin_drm_ade.c
> @@ -608,17 +608,16 @@ static void ade_rdma_set(void __iomem *base, struct drm_framebuffer *fb,
> u32 ch, u32 y, u32 in_h, u32 fmt)
> {
> struct drm_gem_cma_object *obj = drm_fb_cma_get_gem_obj(fb, 0);
> - char *format_name;
> + struct drm_format_name_buf format_name;
> u32 reg_ctrl, reg_addr, reg_size, reg_stride, reg_space, reg_en;
> u32 stride = fb->pitches[0];
> u32 addr = (u32)obj->paddr + y * stride;
>
> DRM_DEBUG_DRIVER("rdma%d: (y=%d, height=%d), stride=%d, paddr=0x%x\n",
> ch + 1, y, in_h, stride, (u32)obj->paddr);
> - format_name = drm_get_format_name(fb->pixel_format);
> DRM_DEBUG_DRIVER("addr=0x%x, fb:%dx%d, pixel_format=%d(%s)\n",
> - addr, fb->width, fb->height, fmt, format_name);
> + addr, fb->width, fb->height, fmt,
> + drm_get_format_name(fb->pixel_format, &format_name));
> - kfree(format_name);
>
> /* get reg offset */
> reg_ctrl = RD_CH_CTRL(ch);
> diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
> index 20638d2..670423e 100644
> --- a/drivers/gpu/drm/i915/i915_debugfs.c
> +++ b/drivers/gpu/drm/i915/i915_debugfs.c
> @@ -2971,7 +2971,7 @@ static void intel_plane_info(struct seq_file *m, struct intel_crtc *intel_crtc)
> for_each_intel_plane_on_crtc(dev, intel_crtc, intel_plane) {
> struct drm_plane_state *state;
> struct drm_plane *plane = &intel_plane->base;
> - char *format_name;
> + struct drm_format_name_buf format_name;
>
> if (!plane->state) {
> seq_puts(m, "plane->state is NULL!\n");
> @@ -2981,9 +2981,9 @@ static void intel_plane_info(struct seq_file *m, struct intel_crtc *intel_crtc)
> state = plane->state;
>
> if (state->fb) {
> - format_name = drm_get_format_name(state->fb->pixel_format);
> + drm_get_format_name(state->fb->pixel_format, &format_name);
> } else {
> - format_name = kstrdup("N/A", GFP_KERNEL);
> + sprintf(format_name.str, "N/A");
> }
>
> seq_printf(m, "\t--Plane id %d: type=%s, crtc_pos=%4dx%4d, crtc_size=%4dx%4d, src_pos=%d.%04ux%d.%04u, src_size=%d.%04ux%d.%04u, format=%s, rotation=%s\n",
> @@ -2999,10 +2999,8 @@ static void intel_plane_info(struct seq_file *m, struct intel_crtc *intel_crtc)
> ((state->src_w & 0xffff) * 15625) >> 10,
> (state->src_h >> 16),
> ((state->src_h & 0xffff) * 15625) >> 10,
> - format_name,
> + format_name.str,
> plane_rotation(state->rotation));
> -
> - kfree(format_name);
> }
> }
>
> diff --git a/drivers/gpu/drm/i915/intel_atomic_plane.c b/drivers/gpu/drm/i915/intel_atomic_plane.c
> index c762ae5..6c76e3d 100644
> --- a/drivers/gpu/drm/i915/intel_atomic_plane.c
> +++ b/drivers/gpu/drm/i915/intel_atomic_plane.c
> @@ -143,7 +143,7 @@ static int intel_plane_atomic_check(struct drm_plane *plane,
> crtc_state->base.enable ? crtc_state->pipe_src_h : 0;
>
> if (state->fb && drm_rotation_90_or_270(state->rotation)) {
> - char *format_name;
> + struct drm_format_name_buf format_name;
>
> if (!(state->fb->modifier[0] == I915_FORMAT_MOD_Y_TILED ||
> state->fb->modifier[0] == I915_FORMAT_MOD_Yf_TILED)) {
> @@ -159,9 +159,9 @@ static int intel_plane_atomic_check(struct drm_plane *plane,
> switch (state->fb->pixel_format) {
> case DRM_FORMAT_C8:
> case DRM_FORMAT_RGB565:
> - format_name = drm_get_format_name(state->fb->pixel_format);
> - DRM_DEBUG_KMS("Unsupported pixel format %s for 90/270!\n", format_name);
> + DRM_DEBUG_KMS("Unsupported pixel format %s for 90/270!\n",
> + drm_get_format_name(state->fb->pixel_format,
> + &format_name));
> - kfree(format_name);
> return -EINVAL;
>
> default:
> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> index 6f8f6ec..8209170 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -12871,7 +12871,7 @@ static void intel_dump_pipe_config(struct intel_crtc *crtc,
>
> DRM_DEBUG_KMS("planes on this crtc\n");
> list_for_each_entry(plane, &dev->mode_config.plane_list, head) {
> - char *format_name;
> + struct drm_format_name_buf format_name;
> intel_plane = to_intel_plane(plane);
> if (intel_plane->pipe != crtc->pipe)
> continue;
> @@ -12884,12 +12884,11 @@ static void intel_dump_pipe_config(struct intel_crtc *crtc,
> continue;
> }
>
> - format_name = drm_get_format_name(fb->pixel_format);
> -
> DRM_DEBUG_KMS("[PLANE:%d:%s] enabled",
> plane->base.id, plane->name);
> DRM_DEBUG_KMS("\tFB:%d, fb = %ux%u format = %s",
> - fb->base.id, fb->width, fb->height, format_name);
> + fb->base.id, fb->width, fb->height,
> + drm_get_format_name(fb->pixel_format, &format_name));
> DRM_DEBUG_KMS("\tscaler:%d src %dx%d+%d+%d dst %dx%d+%d+%d\n",
> state->scaler_id,
> state->base.src.x1 >> 16,
> @@ -12899,8 +12898,6 @@ static void intel_dump_pipe_config(struct intel_crtc *crtc,
> state->base.dst.x1, state->base.dst.y1,
> drm_rect_width(&state->base.dst),
> drm_rect_height(&state->base.dst));
> -
> - kfree(format_name);
> }
> }
>
> @@ -15749,7 +15746,7 @@ static int intel_framebuffer_init(struct drm_device *dev,
> unsigned int tiling = i915_gem_object_get_tiling(obj);
> int ret;
> u32 pitch_limit, stride_alignment;
> - char *format_name;
> + struct drm_format_name_buf format_name;
>
> WARN_ON(!mutex_is_locked(&dev->struct_mutex));
>
> @@ -15840,18 +15837,16 @@ static int intel_framebuffer_init(struct drm_device *dev,
> break;
> case DRM_FORMAT_XRGB1555:
> if (INTEL_INFO(dev)->gen > 3) {
> - format_name = drm_get_format_name(mode_cmd->pixel_format);
> - DRM_DEBUG("unsupported pixel format: %s\n", format_name);
> + DRM_DEBUG("unsupported pixel format: %s\n",
> + drm_get_format_name(mode_cmd->pixel_format, &format_name));
> - kfree(format_name);
> return -EINVAL;
> }
> break;
> case DRM_FORMAT_ABGR8888:
> if (!IS_VALLEYVIEW(dev_priv) && !IS_CHERRYVIEW(dev_priv) &&
> INTEL_INFO(dev)->gen < 9) {
> - format_name = drm_get_format_name(mode_cmd->pixel_format);
> - DRM_DEBUG("unsupported pixel format: %s\n", format_name);
> + DRM_DEBUG("unsupported pixel format: %s\n",
> + drm_get_format_name(mode_cmd->pixel_format, &format_name));
> - kfree(format_name);
> return -EINVAL;
> }
> break;
> @@ -15859,17 +15854,15 @@ static int intel_framebuffer_init(struct drm_device *dev,
> case DRM_FORMAT_XRGB2101010:
> case DRM_FORMAT_XBGR2101010:
> if (INTEL_INFO(dev)->gen < 4) {
> - format_name = drm_get_format_name(mode_cmd->pixel_format);
> - DRM_DEBUG("unsupported pixel format: %s\n", format_name);
> + DRM_DEBUG("unsupported pixel format: %s\n",
> + drm_get_format_name(mode_cmd->pixel_format, &format_name));
> - kfree(format_name);
> return -EINVAL;
> }
> break;
> case DRM_FORMAT_ABGR2101010:
> if (!IS_VALLEYVIEW(dev_priv) && !IS_CHERRYVIEW(dev_priv)) {
> - format_name = drm_get_format_name(mode_cmd->pixel_format);
> - DRM_DEBUG("unsupported pixel format: %s\n", format_name);
> + DRM_DEBUG("unsupported pixel format: %s\n",
> + drm_get_format_name(mode_cmd->pixel_format, &format_name));
> - kfree(format_name);
> return -EINVAL;
> }
> break;
> @@ -15878,16 +15871,14 @@ static int intel_framebuffer_init(struct drm_device *dev,
> case DRM_FORMAT_YVYU:
> case DRM_FORMAT_VYUY:
> if (INTEL_INFO(dev)->gen < 5) {
> - format_name = drm_get_format_name(mode_cmd->pixel_format);
> - DRM_DEBUG("unsupported pixel format: %s\n", format_name);
> + DRM_DEBUG("unsupported pixel format: %s\n",
> + drm_get_format_name(mode_cmd->pixel_format, &format_name));
> - kfree(format_name);
> return -EINVAL;
> }
> break;
> default:
> - format_name = drm_get_format_name(mode_cmd->pixel_format);
> - DRM_DEBUG("unsupported pixel format: %s\n", format_name);
> + DRM_DEBUG("unsupported pixel format: %s\n",
> + drm_get_format_name(mode_cmd->pixel_format, &format_name));
> - kfree(format_name);
> return -EINVAL;
> }
>
> diff --git a/drivers/gpu/drm/radeon/atombios_crtc.c b/drivers/gpu/drm/radeon/atombios_crtc.c
> index 74f99ba..05f4ebe 100644
> --- a/drivers/gpu/drm/radeon/atombios_crtc.c
> +++ b/drivers/gpu/drm/radeon/atombios_crtc.c
> @@ -1156,7 +1156,7 @@ static int dce4_crtc_do_set_base(struct drm_crtc *crtc,
> u32 tmp, viewport_w, viewport_h;
> int r;
> bool bypass_lut = false;
> - char *format_name;
> + struct drm_format_name_buf format_name;
>
> /* no fb bound */
> if (!atomic && !crtc->primary->fb) {
> @@ -1260,9 +1260,8 @@ static int dce4_crtc_do_set_base(struct drm_crtc *crtc,
> bypass_lut = true;
> break;
> default:
> - format_name = drm_get_format_name(target_fb->pixel_format);
> - DRM_ERROR("Unsupported screen format %s\n", format_name);
> + DRM_ERROR("Unsupported screen format %s\n",
> + drm_get_format_name(target_fb->pixel_format, &format_name));
> - kfree(format_name);
> return -EINVAL;
> }
>
> @@ -1473,7 +1472,7 @@ static int avivo_crtc_do_set_base(struct drm_crtc *crtc,
> u32 viewport_w, viewport_h;
> int r;
> bool bypass_lut = false;
> - char *format_name;
> + struct drm_format_name_buf format_name;
>
> /* no fb bound */
> if (!atomic && !crtc->primary->fb) {
> @@ -1563,9 +1562,8 @@ static int avivo_crtc_do_set_base(struct drm_crtc *crtc,
> bypass_lut = true;
> break;
> default:
> - format_name = drm_get_format_name(target_fb->pixel_format);
> - DRM_ERROR("Unsupported screen format %s\n", format_name);
> + DRM_ERROR("Unsupported screen format %s\n",
> + drm_get_format_name(target_fb->pixel_format, &format_name));
> - kfree(format_name);
> return -EINVAL;
> }
>
> diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c b/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c
> index c965514..e3f68cc 100644
> --- a/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c
> +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c
> @@ -985,8 +985,9 @@ static struct drm_framebuffer *vmw_kms_fb_create(struct drm_device *dev,
>
> info = drm_format_info(mode_cmd2->pixel_format);
> if (!info || !info->depth) {
> + struct drm_format_name_buf format_name;
> DRM_ERROR("Unsupported framebuffer format %s\n",
> - drm_get_format_name(mode_cmd2->pixel_format));
> + drm_get_format_name(mode_cmd2->pixel_format, &format_name));
> return ERR_PTR(-EINVAL);
> }
>
> --
> Cheers,
> Eric
>
> _______________________________________________
> Intel-gfx mailing list
> [email protected]
> https://lists.freedesktop.org/mailman/listinfo/intel-gfx

--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch

2016-11-09 01:13:32

[permalink] [raw]

Subject: Re: [Intel-gfx] [PATCH v3] drm: move allocation out of drm_get_format_name()

On Wed, Nov 09, 2016 at 02:09:16AM +0100, Daniel Vetter wrote:
> On Wed, Nov 09, 2016 at 12:17:52AM +0000, Eric Engestrom wrote:
> > The function's behaviour was changed in 90844f00049e, without changing
> > its signature, causing people to keep using it the old way without
> > realising they were now leaking memory.
> > Rob Clark also noticed it was also allocating GFP_KERNEL memory in
> > atomic contexts, breaking them.
> >
> > Instead of having to allocate GFP_ATOMIC memory and fixing the callers
> > to make them cleanup the memory afterwards, let's change the function's
> > signature by having the caller take care of the memory and passing it to
> > the function.
> > The new parameter is a single-field struct in order to enforce the size
> > of its buffer and help callers to correctly manage their memory.
> >
> > Fixes: 90844f00049e ("drm: make drm_get_format_name thread-safe")
> > Cc: Rob Clark <[email protected]>
> > Cc: Christian König <[email protected]>
> > Acked-by: Christian König <[email protected]>
> > Acked-by: Rob Clark <[email protected]>
> > Acked-by: Sinclair Yeh <[email protected]> (vmwgfx)
> > Reviewed-by: Jani Nikula <[email protected]>
> > Suggested-by: Ville Syrjälä <[email protected]>
> > Signed-off-by: Eric Engestrom <[email protected]>
> > ---
> > v3 - fix "Fixes" tag, replace it with an actual commit message
> > - collect ack & r-b
> >
> > v2 - use single-field struct instead of typedef to let the compiler
> > enforce the type (Christian König)
>
> Applied to drm-misc, thanks.

Well, had to drop it again since it didn't compile:

CC [M] drivers/gpu/drm/drm_blend.o
drivers/gpu/drm/drm_atomic.c: In function ‘drm_atomic_plane_print_state’:
drivers/gpu/drm/drm_atomic.c:920:5: error: too few arguments to function ‘drm_get_format_name’
drm_get_format_name(fb->pixel_format));
^~~~~~~~~~~~~~~~~~~
In file included from ./include/drm/drmP.h:71:0,
from drivers/gpu/drm/drm_atomic.c:29:
./include/drm/drm_fourcc.h:65:7: note: declared here
char *drm_get_format_name(uint32_t format, struct drm_format_name_buf *buf);
^~~~~~~~~~~~~~~~~~~

Can you pls rebase onto drm-misc or linux-next or something?

Thanks, Daniel
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch

2016-11-09 11:43:27

[permalink] [raw]

Subject: Re: [Intel-gfx] [PATCH v3] drm: move allocation out of drm_get_format_name()

On Wednesday, 2016-11-09 02:13:25 +0100, Daniel Vetter wrote:
> On Wed, Nov 09, 2016 at 02:09:16AM +0100, Daniel Vetter wrote:
> > On Wed, Nov 09, 2016 at 12:17:52AM +0000, Eric Engestrom wrote:
> > > The function's behaviour was changed in 90844f00049e, without changing
> > > its signature, causing people to keep using it the old way without
> > > realising they were now leaking memory.
> > > Rob Clark also noticed it was also allocating GFP_KERNEL memory in
> > > atomic contexts, breaking them.
> > >
> > > Instead of having to allocate GFP_ATOMIC memory and fixing the callers
> > > to make them cleanup the memory afterwards, let's change the function's
> > > signature by having the caller take care of the memory and passing it to
> > > the function.
> > > The new parameter is a single-field struct in order to enforce the size
> > > of its buffer and help callers to correctly manage their memory.
> > >
> > > Fixes: 90844f00049e ("drm: make drm_get_format_name thread-safe")
> > > Cc: Rob Clark <[email protected]>
> > > Cc: Christian König <[email protected]>
> > > Acked-by: Christian König <[email protected]>
> > > Acked-by: Rob Clark <[email protected]>
> > > Acked-by: Sinclair Yeh <[email protected]> (vmwgfx)
> > > Reviewed-by: Jani Nikula <[email protected]>
> > > Suggested-by: Ville Syrjälä <[email protected]>
> > > Signed-off-by: Eric Engestrom <[email protected]>
> > > ---
> > > v3 - fix "Fixes" tag, replace it with an actual commit message
> > > - collect ack & r-b
> > >
> > > v2 - use single-field struct instead of typedef to let the compiler
> > > enforce the type (Christian König)
> >
> > Applied to drm-misc, thanks.
>
> Well, had to drop it again since it didn't compile:
>
>
> CC [M] drivers/gpu/drm/drm_blend.o
> drivers/gpu/drm/drm_atomic.c: In function ‘drm_atomic_plane_print_state’:
> drivers/gpu/drm/drm_atomic.c:920:5: error: too few arguments to function ‘drm_get_format_name’
> drm_get_format_name(fb->pixel_format));
> ^~~~~~~~~~~~~~~~~~~
> In file included from ./include/drm/drmP.h:71:0,
> from drivers/gpu/drm/drm_atomic.c:29:
> ./include/drm/drm_fourcc.h:65:7: note: declared here
> char *drm_get_format_name(uint32_t format, struct drm_format_name_buf *buf);
> ^~~~~~~~~~~~~~~~~~~
>
> Can you pls rebase onto drm-misc or linux-next or something?

That was based on airlied/drm-next (last fetched on Sunday I think),
I can rebase it on drm-misc if it helps, but it seems older than
drm-next.
Should I just rebase on top of current head of drm-next?

2016-11-09 13:13:43

[permalink] [raw]

Subject: Re: [Intel-gfx] [PATCH v3] drm: move allocation out of drm_get_format_name()

On Wed, Nov 9, 2016 at 12:42 PM, Eric Engestrom
<[email protected]> wrote:
>> Well, had to drop it again since it didn't compile:
>>
>>
>> CC [M] drivers/gpu/drm/drm_blend.o
>> drivers/gpu/drm/drm_atomic.c: In function ‘drm_atomic_plane_print_state’:
>> drivers/gpu/drm/drm_atomic.c:920:5: error: too few arguments to function ‘drm_get_format_name’
>> drm_get_format_name(fb->pixel_format));
>> ^~~~~~~~~~~~~~~~~~~
>> In file included from ./include/drm/drmP.h:71:0,
>> from drivers/gpu/drm/drm_atomic.c:29:
>> ./include/drm/drm_fourcc.h:65:7: note: declared here
>> char *drm_get_format_name(uint32_t format, struct drm_format_name_buf *buf);
>> ^~~~~~~~~~~~~~~~~~~
>>
>> Can you pls rebase onto drm-misc or linux-next or something?
>
> That was based on airlied/drm-next (last fetched on Sunday I think),
> I can rebase it on drm-misc if it helps, but it seems older than
> drm-next.
> Should I just rebase on top of current head of drm-next?

It needs to be drm-misc (linux-next doesn't have it yet) due to the
new atomic debug work that we just landed. I'm working on drm-tip as a
drm local integration tree to ease pains like these a bit, but that
doesn't really exist yet.
-Daniel
--
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch

2016-11-09 16:59:37

[permalink] [raw]

Subject: Re: [Intel-gfx] [PATCH v3] drm: move allocation out of drm_get_format_name()

On Wednesday, 2016-11-09 14:13:40 +0100, Daniel Vetter wrote:
> On Wed, Nov 9, 2016 at 12:42 PM, Eric Engestrom
> <[email protected]> wrote:
> >> Well, had to drop it again since it didn't compile:
> >>
> >>
> >> CC [M] drivers/gpu/drm/drm_blend.o
> >> drivers/gpu/drm/drm_atomic.c: In function ‘drm_atomic_plane_print_state’:
> >> drivers/gpu/drm/drm_atomic.c:920:5: error: too few arguments to function ‘drm_get_format_name’
> >> drm_get_format_name(fb->pixel_format));
> >> ^~~~~~~~~~~~~~~~~~~
> >> In file included from ./include/drm/drmP.h:71:0,
> >> from drivers/gpu/drm/drm_atomic.c:29:
> >> ./include/drm/drm_fourcc.h:65:7: note: declared here
> >> char *drm_get_format_name(uint32_t format, struct drm_format_name_buf *buf);
> >> ^~~~~~~~~~~~~~~~~~~
> >>
> >> Can you pls rebase onto drm-misc or linux-next or something?
> >
> > That was based on airlied/drm-next (last fetched on Sunday I think),
> > I can rebase it on drm-misc if it helps, but it seems older than
> > drm-next.
> > Should I just rebase on top of current head of drm-next?
>
> It needs to be drm-misc (linux-next doesn't have it yet) due to the
> new atomic debug work that we just landed. I'm working on drm-tip as a
> drm local integration tree to ease pains like these a bit, but that
> doesn't really exist yet.

I'm confused as to how the different trees and branches merge back to
Torvalds' tree (I'm interested in particular in drm), and I'm not sure
which branch you want me to rebase on in the drm-misc tree [1],
especially since all of them are older than drm-next [2].

I'll try to rebase on drm-misc-fixes (currently at 4da5caa6a6f82cda3193)
as it sounds about right, but it doesn't apply at all, so it'll take
a little while.

Could you give me a quick explanation or point me to a doc/page that
explains how the various trees and branches get merged?
I googled a bit and found this doc [4] by Jani, but it doesn't mention
drm-misc for instance, so I'm not sure how up-to-date and
non-intel-specific it is.

Looking at this page, something just occurred to me: did you mean
drm-fixes [3], instead of one of the branches on drm-misc?

Cheers,
Eric

[1] git://anongit.freedesktop.org/drm/drm-misc
[2] git://people.freedesktop.org/~airlied/linux drm-next
[2] git://people.freedesktop.org/~airlied/linux drm-fixes
[3] https://01.org/linuxgraphics/gfx-docs/maintainer-tools/drm-intel.html

2016-11-10 10:03:14

by Laurent Pinchart

[permalink] [raw]

Subject: Re: [Intel-gfx] [PATCH v3] drm: move allocation out of drm_get_format_name()

Hi Eric,

On Wednesday 09 Nov 2016 16:59:31 Eric Engestrom wrote:
> On Wednesday, 2016-11-09 14:13:40 +0100, Daniel Vetter wrote:
> > On Wed, Nov 9, 2016 at 12:42 PM, Eric Engestrom wrote:
> > >> Well, had to drop it again since it didn't compile:
> > >> CC [M] drivers/gpu/drm/drm_blend.o
> > >>
> > >> drivers/gpu/drm/drm_atomic.c: In function
> > >> ‘drm_atomic_plane_print_state’:
> > >> drivers/gpu/drm/drm_atomic.c:920:5: error: too few arguments to
> > >> function ‘drm_get_format_name’> >>
> > >> drm_get_format_name(fb->pixel_format));
> > >> ^~~~~~~~~~~~~~~~~~~
> > >>
> > >> In file included from ./include/drm/drmP.h:71:0,
> > >>
> > >> from drivers/gpu/drm/drm_atomic.c:29:
> > >> ./include/drm/drm_fourcc.h:65:7: note: declared here
> > >>
> > >> char *drm_get_format_name(uint32_t format, struct drm_format_name_buf
> > >> *buf);> >>
> > >> ^~~~~~~~~~~~~~~~~~~
> > >>
> > >> Can you pls rebase onto drm-misc or linux-next or something?
> > >
> > > That was based on airlied/drm-next (last fetched on Sunday I think),
> > > I can rebase it on drm-misc if it helps, but it seems older than
> > > drm-next. Should I just rebase on top of current head of drm-next?
> >
> > It needs to be drm-misc (linux-next doesn't have it yet) due to the
> > new atomic debug work that we just landed. I'm working on drm-tip as a
> > drm local integration tree to ease pains like these a bit, but that
> > doesn't really exist yet.
>
> I'm confused as to how the different trees and branches merge back to
> Torvalds' tree (I'm interested in particular in drm), and I'm not sure
> which branch you want me to rebase on in the drm-misc tree [1],
> especially since all of them are older than drm-next [2].
>
> I'll try to rebase on drm-misc-fixes (currently at 4da5caa6a6f82cda3193)
> as it sounds about right, but it doesn't apply at all, so it'll take
> a little while.

While at it, could you make the function return a const char * ?

By the way, while this is an improvement over the current situation in that it
fixes the missing kfree() issue, I wonder whether the problem we're trying to
solve should be addressed at a more global level.

The issue here is that printk can't format the fourcc as a string by itself.
There's a bunch of places in the kernel where a similar formatting problem
occurs. In a few occasions it has been solved by extending printk with
additional format specifiers (such as for MAC/IP addresses, GUIDs, various
kind of device names, ...). DRM fourccs are probably too DRM specific to be
worth a format specifier, but I wonder whether we could introduce a new
specifier that takes a function pointer as a formatting helper. Another
similarly crazy option would be a format specifier for strings that would free
the passed pointer after printing it.

> Could you give me a quick explanation or point me to a doc/page that
> explains how the various trees and branches get merged?
> I googled a bit and found this doc [4] by Jani, but it doesn't mention
> drm-misc for instance, so I'm not sure how up-to-date and
> non-intel-specific it is.
>
> Looking at this page, something just occurred to me: did you mean
> drm-fixes [3], instead of one of the branches on drm-misc?
>
> Cheers,
> Eric
>
> [1] git://anongit.freedesktop.org/drm/drm-misc
> [2] git://people.freedesktop.org/~airlied/linux drm-next
> [2] git://people.freedesktop.org/~airlied/linux drm-fixes
> [3] https://01.org/linuxgraphics/gfx-docs/maintainer-tools/drm-intel.html

--
Regards,

Laurent Pinchart

2016-11-10 10:30:18

[permalink] [raw]

Subject: Re: [Intel-gfx] [PATCH v3] drm: move allocation out of drm_get_format_name()

On Thu, 10 Nov 2016, Laurent Pinchart <[email protected]> wrote:
> Hi Eric,
>
> On Wednesday 09 Nov 2016 16:59:31 Eric Engestrom wrote:
>> On Wednesday, 2016-11-09 14:13:40 +0100, Daniel Vetter wrote:
>> > On Wed, Nov 9, 2016 at 12:42 PM, Eric Engestrom wrote:
>> > >> Well, had to drop it again since it didn't compile:
>> > >> CC [M] drivers/gpu/drm/drm_blend.o
>> > >>
>> > >> drivers/gpu/drm/drm_atomic.c: In function
>> > >> ‘drm_atomic_plane_print_state’:
>> > >> drivers/gpu/drm/drm_atomic.c:920:5: error: too few arguments to
>> > >> function ‘drm_get_format_name’> >>
>> > >> drm_get_format_name(fb->pixel_format));
>> > >> ^~~~~~~~~~~~~~~~~~~
>> > >>
>> > >> In file included from ./include/drm/drmP.h:71:0,
>> > >>
>> > >> from drivers/gpu/drm/drm_atomic.c:29:
>> > >> ./include/drm/drm_fourcc.h:65:7: note: declared here
>> > >>
>> > >> char *drm_get_format_name(uint32_t format, struct drm_format_name_buf
>> > >> *buf);> >>
>> > >> ^~~~~~~~~~~~~~~~~~~
>> > >>
>> > >> Can you pls rebase onto drm-misc or linux-next or something?
>> > >
>> > > That was based on airlied/drm-next (last fetched on Sunday I think),
>> > > I can rebase it on drm-misc if it helps, but it seems older than
>> > > drm-next. Should I just rebase on top of current head of drm-next?
>> >
>> > It needs to be drm-misc (linux-next doesn't have it yet) due to the
>> > new atomic debug work that we just landed. I'm working on drm-tip as a
>> > drm local integration tree to ease pains like these a bit, but that
>> > doesn't really exist yet.
>>
>> I'm confused as to how the different trees and branches merge back to
>> Torvalds' tree (I'm interested in particular in drm), and I'm not sure
>> which branch you want me to rebase on in the drm-misc tree [1],
>> especially since all of them are older than drm-next [2].
>>
>> I'll try to rebase on drm-misc-fixes (currently at 4da5caa6a6f82cda3193)
>> as it sounds about right, but it doesn't apply at all, so it'll take
>> a little while.
>
> While at it, could you make the function return a const char * ?

I thought I mentioned that too, though I didn't insist.

> By the way, while this is an improvement over the current situation in that it
> fixes the missing kfree() issue, I wonder whether the problem we're trying to
> solve should be addressed at a more global level.

Maybe, but let's not block this one!

> The issue here is that printk can't format the fourcc as a string by itself.
> There's a bunch of places in the kernel where a similar formatting problem
> occurs. In a few occasions it has been solved by extending printk with
> additional format specifiers (such as for MAC/IP addresses, GUIDs, various
> kind of device names, ...). DRM fourccs are probably too DRM specific to be
> worth a format specifier, but I wonder whether we could introduce a new
> specifier that takes a function pointer as a formatting helper. Another
> similarly crazy option would be a format specifier for strings that would free
> the passed pointer after printing it.

I think there are too many non-standard format specifiers already. I
can't review the non-standard format strings without looking at
Documentation/prink-formats.txt first. The formatting hook would be a
generic alternative, but that's more than a little scary from the
security standpoint. And what if the hook has to allocate memory? Can't
do that in atomic contexts.

BR,
Jani.

>
>> Could you give me a quick explanation or point me to a doc/page that
>> explains how the various trees and branches get merged?
>> I googled a bit and found this doc [4] by Jani, but it doesn't mention
>> drm-misc for instance, so I'm not sure how up-to-date and
>> non-intel-specific it is.
>>
>> Looking at this page, something just occurred to me: did you mean
>> drm-fixes [3], instead of one of the branches on drm-misc?
>>
>> Cheers,
>> Eric
>>
>> [1] git://anongit.freedesktop.org/drm/drm-misc
>> [2] git://people.freedesktop.org/~airlied/linux drm-next
>> [2] git://people.freedesktop.org/~airlied/linux drm-fixes
>> [3] https://01.org/linuxgraphics/gfx-docs/maintainer-tools/drm-intel.html

--
Jani Nikula, Intel Open Source Technology Center

2016-11-10 10:59:35

by Laurent Pinchart

[permalink] [raw]

Subject: Re: [Intel-gfx] [PATCH v3] drm: move allocation out of drm_get_format_name()

Hi Jani,

On Thursday 10 Nov 2016 12:30:09 Jani Nikula wrote:
> On Thu, 10 Nov 2016, Laurent Pinchart wrote:
> > On Wednesday 09 Nov 2016 16:59:31 Eric Engestrom wrote:
> >> On Wednesday, 2016-11-09 14:13:40 +0100, Daniel Vetter wrote:
> >>> On Wed, Nov 9, 2016 at 12:42 PM, Eric Engestrom wrote:
> >>>>> Well, had to drop it again since it didn't compile:
> >>>>> CC [M] drivers/gpu/drm/drm_blend.o
> >>>>>
> >>>>> drivers/gpu/drm/drm_atomic.c: In function
> >>>>> ‘drm_atomic_plane_print_state’:
> >>>>> drivers/gpu/drm/drm_atomic.c:920:5: error: too few arguments to
> >>>>> function ‘drm_get_format_name’> >>
> >>>>> drm_get_format_name(fb->pixel_format));
> >>>>> ^~~~~~~~~~~~~~~~~~~
> >>>>> In file included from ./include/drm/drmP.h:71:0,
> >>>>> from drivers/gpu/drm/drm_atomic.c:29:
> >>>>> ./include/drm/drm_fourcc.h:65:7: note: declared here
> >>>>> char *drm_get_format_name(uint32_t format, struct
> >>>>> drm_format_name_buf *buf);
> >>>>> ^~~~~~~~~~~~~~~~~~~
> >>>>>
> >>>>> Can you pls rebase onto drm-misc or linux-next or something?
> >>>>
> >>>> That was based on airlied/drm-next (last fetched on Sunday I think),
> >>>> I can rebase it on drm-misc if it helps, but it seems older than
> >>>> drm-next. Should I just rebase on top of current head of drm-next?
> >>>
> >>> It needs to be drm-misc (linux-next doesn't have it yet) due to the
> >>> new atomic debug work that we just landed. I'm working on drm-tip as a
> >>> drm local integration tree to ease pains like these a bit, but that
> >>> doesn't really exist yet.
> >>
> >> I'm confused as to how the different trees and branches merge back to
> >> Torvalds' tree (I'm interested in particular in drm), and I'm not sure
> >> which branch you want me to rebase on in the drm-misc tree [1],
> >> especially since all of them are older than drm-next [2].
> >>
> >> I'll try to rebase on drm-misc-fixes (currently at 4da5caa6a6f82cda3193)
> >> as it sounds about right, but it doesn't apply at all, so it'll take
> >> a little while.
> >
> > While at it, could you make the function return a const char * ?
>
> I thought I mentioned that too, though I didn't insist.

You did, and I think Eric agreed to change that.

> > By the way, while this is an improvement over the current situation in
> > that it fixes the missing kfree() issue, I wonder whether the problem
> > we're trying to solve should be addressed at a more global level.
>
> Maybe, but let's not block this one!

Sure, that wasn't the intent of my e-mail.

> > The issue here is that printk can't format the fourcc as a string by
> > itself. There's a bunch of places in the kernel where a similar
> > formatting problem occurs. In a few occasions it has been solved by
> > extending printk with additional format specifiers (such as for MAC/IP
> > addresses, GUIDs, various kind of device names, ...). DRM fourccs are
> > probably too DRM specific to be worth a format specifier, but I wonder
> > whether we could introduce a new specifier that takes a function pointer
> > as a formatting helper. Another similarly crazy option would be a format
> > specifier for strings that would free the passed pointer after printing
> > it.
>
> I think there are too many non-standard format specifiers already. I
> can't review the non-standard format strings without looking at
> Documentation/prink-formats.txt first. The formatting hook would be a
> generic alternative, but that's more than a little scary from the
> security standpoint. And what if the hook has to allocate memory? Can't
> do that in atomic contexts.

There are lots of details to sort out obviously and I don't have an answer to
all questions yet. I think it would be worth researching this, as the problem
isn't specific to DRM/KMS.

> >> Could you give me a quick explanation or point me to a doc/page that
> >> explains how the various trees and branches get merged?
> >> I googled a bit and found this doc [4] by Jani, but it doesn't mention
> >> drm-misc for instance, so I'm not sure how up-to-date and
> >> non-intel-specific it is.
> >>
> >> Looking at this page, something just occurred to me: did you mean
> >> drm-fixes [3], instead of one of the branches on drm-misc?
> >>
> >> Cheers,
> >>
> >> Eric
> >>
> >> [1] git://anongit.freedesktop.org/drm/drm-misc
> >> [2] git://people.freedesktop.org/~airlied/linux drm-next
> >> [2] git://people.freedesktop.org/~airlied/linux drm-fixes
> >> [3] https://01.org/linuxgraphics/gfx-docs/maintainer-tools/drm-intel.html

--
Regards,

Laurent Pinchart

2016-11-10 11:03:31

[permalink] [raw]

Subject: Re: [Intel-gfx] [PATCH v3] drm: move allocation out of drm_get_format_name()

On Thu, 10 Nov 2016, Laurent Pinchart <[email protected]> wrote:
> Hi Jani,
>
> On Thursday 10 Nov 2016 12:30:09 Jani Nikula wrote:
>> On Thu, 10 Nov 2016, Laurent Pinchart wrote:
>> > The issue here is that printk can't format the fourcc as a string by
>> > itself. There's a bunch of places in the kernel where a similar
>> > formatting problem occurs. In a few occasions it has been solved by
>> > extending printk with additional format specifiers (such as for MAC/IP
>> > addresses, GUIDs, various kind of device names, ...). DRM fourccs are
>> > probably too DRM specific to be worth a format specifier, but I wonder
>> > whether we could introduce a new specifier that takes a function pointer
>> > as a formatting helper. Another similarly crazy option would be a format
>> > specifier for strings that would free the passed pointer after printing
>> > it.
>>
>> I think there are too many non-standard format specifiers already. I
>> can't review the non-standard format strings without looking at
>> Documentation/prink-formats.txt first. The formatting hook would be a
>> generic alternative, but that's more than a little scary from the
>> security standpoint. And what if the hook has to allocate memory? Can't
>> do that in atomic contexts.
>
> There are lots of details to sort out obviously and I don't have an answer to
> all questions yet. I think it would be worth researching this, as the problem
> isn't specific to DRM/KMS.

That's easy to agree to; as much as you didn't mean to shoot down the
patch, I didn't mean to shoot down your idea! :)

BR,
Jani.

--
Jani Nikula, Intel Open Source Technology Center

2016-11-11 09:26:10

[permalink] [raw]

Subject: Re: [Intel-gfx] [PATCH v3] drm: move allocation out of drm_get_format_name()

On Wed, Nov 09, 2016 at 04:59:31PM +0000, Eric Engestrom wrote:
> On Wednesday, 2016-11-09 14:13:40 +0100, Daniel Vetter wrote:
> > On Wed, Nov 9, 2016 at 12:42 PM, Eric Engestrom
> > <[email protected]> wrote:
> > >> Well, had to drop it again since it didn't compile:
> > >>
> > >>
> > >> CC [M] drivers/gpu/drm/drm_blend.o
> > >> drivers/gpu/drm/drm_atomic.c: In function ‘drm_atomic_plane_print_state’:
> > >> drivers/gpu/drm/drm_atomic.c:920:5: error: too few arguments to function ‘drm_get_format_name’
> > >> drm_get_format_name(fb->pixel_format));
> > >> ^~~~~~~~~~~~~~~~~~~
> > >> In file included from ./include/drm/drmP.h:71:0,
> > >> from drivers/gpu/drm/drm_atomic.c:29:
> > >> ./include/drm/drm_fourcc.h:65:7: note: declared here
> > >> char *drm_get_format_name(uint32_t format, struct drm_format_name_buf *buf);
> > >> ^~~~~~~~~~~~~~~~~~~
> > >>
> > >> Can you pls rebase onto drm-misc or linux-next or something?
> > >
> > > That was based on airlied/drm-next (last fetched on Sunday I think),
> > > I can rebase it on drm-misc if it helps, but it seems older than
> > > drm-next.
> > > Should I just rebase on top of current head of drm-next?
> >
> > It needs to be drm-misc (linux-next doesn't have it yet) due to the
> > new atomic debug work that we just landed. I'm working on drm-tip as a
> > drm local integration tree to ease pains like these a bit, but that
> > doesn't really exist yet.
>
> I'm confused as to how the different trees and branches merge back to
> Torvalds' tree (I'm interested in particular in drm), and I'm not sure
> which branch you want me to rebase on in the drm-misc tree [1],
> especially since all of them are older than drm-next [2].

Dave just pulled in all outstanding pull requests, so just basing on top
of his drm-next should be good enough.

> I'll try to rebase on drm-misc-fixes (currently at 4da5caa6a6f82cda3193)
> as it sounds about right, but it doesn't apply at all, so it'll take
> a little while.
>
> Could you give me a quick explanation or point me to a doc/page that
> explains how the various trees and branches get merged?
> I googled a bit and found this doc [4] by Jani, but it doesn't mention
> drm-misc for instance, so I'm not sure how up-to-date and
> non-intel-specific it is.

We atm don't have it :( drm-misc was kinda just a (very long running)
experiment, but I want to know make it official. Unfortunately the
scripting rework to split out a new drm-misc.git repo is taking a bit
longer. Atm things are still in flux, but I hope that'll settle soon-ish.

> Looking at this page, something just occurred to me: did you mean
> drm-fixes [3], instead of one of the branches on drm-misc?
>
> Cheers,
> Eric
>
> [1] git://anongit.freedesktop.org/drm/drm-misc

Yeah, that's the new location, but atm it's just under testing and it's
not the real drm-misc. That one is in drm-intel.git, in the topic/drm-misc
branch.

> [2] git://people.freedesktop.org/~airlied/linux drm-next
> [2] git://people.freedesktop.org/~airlied/linux drm-fixes
> [3] https://01.org/linuxgraphics/gfx-docs/maintainer-tools/drm-intel.html

https://01.org/linuxgraphics/gfx-docs/maintainer-tools/drm-misc.html

We need to flesh that out, and maybe feature it a bit more prominently.
-Daniel
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch

2016-11-12 01:16:30