From: Anson Huang <[email protected]>
When SoC's revision value is 0, SoC driver will print out
"unknown" in sysfs's revision node, this "unknown" is a
static string which can NOT be freed, this will caused below
kernel dump in later error path which calls kfree:
kernel BUG at mm/slub.c:3942!
Internal error: Oops - BUG: 0 [#1] PREEMPT SMP
Modules linked in:
CPU: 2 PID: 1 Comm: swapper/0 Not tainted 5.2.0-rc4-next-20190611-00023-g705146c-dirty #2197
Hardware name: NXP i.MX8MQ EVK (DT)
pstate: 60000005 (nZCv daif -PAN -UAO)
pc : kfree+0x170/0x1b0
lr : imx8_soc_init+0xc0/0xe4
sp : ffff00001003bd10
x29: ffff00001003bd10 x28: ffff00001121e0a0
x27: ffff000011482000 x26: ffff00001117068c
x25: ffff00001121e100 x24: ffff000011482000
x23: ffff000010fe2b58 x22: ffff0000111b9ab0
x21: ffff8000bd9dfba0 x20: ffff0000111b9b70
x19: ffff7e000043f880 x18: 0000000000001000
x17: ffff000010d05fa0 x16: ffff0000122e0000
x15: 0140000000000000 x14: 0000000030360000
x13: ffff8000b94b5bb0 x12: 0000000000000038
x11: ffffffffffffffff x10: ffffffffffffffff
x9 : 0000000000000003 x8 : ffff8000b9488147
x7 : ffff00001003bc00 x6 : 0000000000000000
x5 : 0000000000000003 x4 : 0000000000000003
x3 : 0000000000000003 x2 : b8793acd604edf00
x1 : ffff7e000043f880 x0 : ffff7e000043f888
Call trace:
kfree+0x170/0x1b0
imx8_soc_init+0xc0/0xe4
do_one_initcall+0x58/0x1b8
kernel_init_freeable+0x1cc/0x288
kernel_init+0x10/0x100
ret_from_fork+0x10/0x18
This patch fixes this potential kernel dump when a chip's
revision is "unknown", it is done by checking whether the
revision space can be freed.
Fixes: a7e26f356ca1 ("soc: imx: Add generic i.MX8 SoC driver")
Signed-off-by: Anson Huang <[email protected]>
---
Changes since V1:
- still need the "unknown" info for revision to avoid confusion, so fix this issue
by checking whether the revision space can be freed before freeing it.
---
drivers/soc/imx/soc-imx8.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/soc/imx/soc-imx8.c b/drivers/soc/imx/soc-imx8.c
index 02309a2..5c7f330 100644
--- a/drivers/soc/imx/soc-imx8.c
+++ b/drivers/soc/imx/soc-imx8.c
@@ -155,7 +155,8 @@ static int __init imx8_soc_init(void)
return 0;
free_rev:
- kfree(soc_dev_attr->revision);
+ if (strcmp(soc_dev_attr->revision, "unknown"))
+ kfree(soc_dev_attr->revision);
free_soc:
kfree(soc_dev_attr);
of_node_put(root);
--
2.7.4
From: Anson Huang <[email protected]>
There is common of_root for reference, no need to find it
from DT again, use of_root directly to make driver simple.
Signed-off-by: Anson Huang <[email protected]>
Reviewed-by: Dong Aisheng <[email protected]>
---
No changes.
---
drivers/soc/imx/soc-imx8.c | 9 ++-------
1 file changed, 2 insertions(+), 7 deletions(-)
diff --git a/drivers/soc/imx/soc-imx8.c b/drivers/soc/imx/soc-imx8.c
index 5c7f330..b459bf2 100644
--- a/drivers/soc/imx/soc-imx8.c
+++ b/drivers/soc/imx/soc-imx8.c
@@ -105,7 +105,6 @@ static int __init imx8_soc_init(void)
{
struct soc_device_attribute *soc_dev_attr;
struct soc_device *soc_dev;
- struct device_node *root;
const struct of_device_id *id;
u32 soc_rev = 0;
const struct imx8_soc_data *data;
@@ -117,12 +116,11 @@ static int __init imx8_soc_init(void)
soc_dev_attr->family = "Freescale i.MX";
- root = of_find_node_by_path("/");
- ret = of_property_read_string(root, "model", &soc_dev_attr->machine);
+ ret = of_property_read_string(of_root, "model", &soc_dev_attr->machine);
if (ret)
goto free_soc;
- id = of_match_node(imx8_soc_match, root);
+ id = of_match_node(imx8_soc_match, of_root);
if (!id) {
ret = -ENODEV;
goto free_soc;
@@ -147,8 +145,6 @@ static int __init imx8_soc_init(void)
goto free_rev;
}
- of_node_put(root);
-
if (IS_ENABLED(CONFIG_ARM_IMX_CPUFREQ_DT))
platform_device_register_simple("imx-cpufreq-dt", -1, NULL, 0);
@@ -159,7 +155,6 @@ static int __init imx8_soc_init(void)
kfree(soc_dev_attr->revision);
free_soc:
kfree(soc_dev_attr);
- of_node_put(root);
return ret;
}
device_initcall(imx8_soc_init);
--
2.7.4
On Fri, Jun 14, 2019 at 04:07:47PM +0800, [email protected] wrote:
> From: Anson Huang <[email protected]>
>
> When SoC's revision value is 0, SoC driver will print out
> "unknown" in sysfs's revision node, this "unknown" is a
> static string which can NOT be freed, this will caused below
> kernel dump in later error path which calls kfree:
>
> kernel BUG at mm/slub.c:3942!
> Internal error: Oops - BUG: 0 [#1] PREEMPT SMP
> Modules linked in:
> CPU: 2 PID: 1 Comm: swapper/0 Not tainted 5.2.0-rc4-next-20190611-00023-g705146c-dirty #2197
> Hardware name: NXP i.MX8MQ EVK (DT)
> pstate: 60000005 (nZCv daif -PAN -UAO)
> pc : kfree+0x170/0x1b0
> lr : imx8_soc_init+0xc0/0xe4
> sp : ffff00001003bd10
> x29: ffff00001003bd10 x28: ffff00001121e0a0
> x27: ffff000011482000 x26: ffff00001117068c
> x25: ffff00001121e100 x24: ffff000011482000
> x23: ffff000010fe2b58 x22: ffff0000111b9ab0
> x21: ffff8000bd9dfba0 x20: ffff0000111b9b70
> x19: ffff7e000043f880 x18: 0000000000001000
> x17: ffff000010d05fa0 x16: ffff0000122e0000
> x15: 0140000000000000 x14: 0000000030360000
> x13: ffff8000b94b5bb0 x12: 0000000000000038
> x11: ffffffffffffffff x10: ffffffffffffffff
> x9 : 0000000000000003 x8 : ffff8000b9488147
> x7 : ffff00001003bc00 x6 : 0000000000000000
> x5 : 0000000000000003 x4 : 0000000000000003
> x3 : 0000000000000003 x2 : b8793acd604edf00
> x1 : ffff7e000043f880 x0 : ffff7e000043f888
> Call trace:
> kfree+0x170/0x1b0
> imx8_soc_init+0xc0/0xe4
> do_one_initcall+0x58/0x1b8
> kernel_init_freeable+0x1cc/0x288
> kernel_init+0x10/0x100
> ret_from_fork+0x10/0x18
>
> This patch fixes this potential kernel dump when a chip's
> revision is "unknown", it is done by checking whether the
> revision space can be freed.
>
> Fixes: a7e26f356ca1 ("soc: imx: Add generic i.MX8 SoC driver")
> Signed-off-by: Anson Huang <[email protected]>
Applied, thanks.
On Fri, Jun 14, 2019 at 04:07:48PM +0800, [email protected] wrote:
> From: Anson Huang <[email protected]>
>
> There is common of_root for reference, no need to find it
> from DT again, use of_root directly to make driver simple.
>
> Signed-off-by: Anson Huang <[email protected]>
> Reviewed-by: Dong Aisheng <[email protected]>
It cannot be applied. Please resend by basing on my imx/drivers branch.
Shawn
> ---
> No changes.
> ---
> drivers/soc/imx/soc-imx8.c | 9 ++-------
> 1 file changed, 2 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/soc/imx/soc-imx8.c b/drivers/soc/imx/soc-imx8.c
> index 5c7f330..b459bf2 100644
> --- a/drivers/soc/imx/soc-imx8.c
> +++ b/drivers/soc/imx/soc-imx8.c
> @@ -105,7 +105,6 @@ static int __init imx8_soc_init(void)
> {
> struct soc_device_attribute *soc_dev_attr;
> struct soc_device *soc_dev;
> - struct device_node *root;
> const struct of_device_id *id;
> u32 soc_rev = 0;
> const struct imx8_soc_data *data;
> @@ -117,12 +116,11 @@ static int __init imx8_soc_init(void)
>
> soc_dev_attr->family = "Freescale i.MX";
>
> - root = of_find_node_by_path("/");
> - ret = of_property_read_string(root, "model", &soc_dev_attr->machine);
> + ret = of_property_read_string(of_root, "model", &soc_dev_attr->machine);
> if (ret)
> goto free_soc;
>
> - id = of_match_node(imx8_soc_match, root);
> + id = of_match_node(imx8_soc_match, of_root);
> if (!id) {
> ret = -ENODEV;
> goto free_soc;
> @@ -147,8 +145,6 @@ static int __init imx8_soc_init(void)
> goto free_rev;
> }
>
> - of_node_put(root);
> -
> if (IS_ENABLED(CONFIG_ARM_IMX_CPUFREQ_DT))
> platform_device_register_simple("imx-cpufreq-dt", -1, NULL, 0);
>
> @@ -159,7 +155,6 @@ static int __init imx8_soc_init(void)
> kfree(soc_dev_attr->revision);
> free_soc:
> kfree(soc_dev_attr);
> - of_node_put(root);
> return ret;
> }
> device_initcall(imx8_soc_init);
> --
> 2.7.4
>
Hi, Shawn
> -----Original Message-----
> From: Shawn Guo <[email protected]>
> Sent: Tuesday, June 18, 2019 5:15 PM
> To: Anson Huang <[email protected]>
> Cc: [email protected]; [email protected]; [email protected];
> Leonard Crestez <[email protected]>; [email protected];
> Abel Vesa <[email protected]>; [email protected];
> [email protected]; dl-linux-imx <[email protected]>
> Subject: Re: [PATCH V2 2/2] soc: imx8: Use existing of_root directly
>
> On Fri, Jun 14, 2019 at 04:07:48PM +0800, [email protected] wrote:
> > From: Anson Huang <[email protected]>
> >
> > There is common of_root for reference, no need to find it from DT
> > again, use of_root directly to make driver simple.
> >
> > Signed-off-by: Anson Huang <[email protected]>
> > Reviewed-by: Dong Aisheng <[email protected]>
>
> It cannot be applied. Please resend by basing on my imx/drivers branch.
OK, just resent, there is a soc driver patch in linux-next, previously I did it based on it.
Now I change it to your git repo, you could meet conflict during merge.
Thanks,
Anson
>
> Shawn
>
> > ---
> > No changes.
> > ---
> > drivers/soc/imx/soc-imx8.c | 9 ++-------
> > 1 file changed, 2 insertions(+), 7 deletions(-)
> >
> > diff --git a/drivers/soc/imx/soc-imx8.c b/drivers/soc/imx/soc-imx8.c
> > index 5c7f330..b459bf2 100644
> > --- a/drivers/soc/imx/soc-imx8.c
> > +++ b/drivers/soc/imx/soc-imx8.c
> > @@ -105,7 +105,6 @@ static int __init imx8_soc_init(void) {
> > struct soc_device_attribute *soc_dev_attr;
> > struct soc_device *soc_dev;
> > - struct device_node *root;
> > const struct of_device_id *id;
> > u32 soc_rev = 0;
> > const struct imx8_soc_data *data;
> > @@ -117,12 +116,11 @@ static int __init imx8_soc_init(void)
> >
> > soc_dev_attr->family = "Freescale i.MX";
> >
> > - root = of_find_node_by_path("/");
> > - ret = of_property_read_string(root, "model", &soc_dev_attr-
> >machine);
> > + ret = of_property_read_string(of_root, "model",
> > +&soc_dev_attr->machine);
> > if (ret)
> > goto free_soc;
> >
> > - id = of_match_node(imx8_soc_match, root);
> > + id = of_match_node(imx8_soc_match, of_root);
> > if (!id) {
> > ret = -ENODEV;
> > goto free_soc;
> > @@ -147,8 +145,6 @@ static int __init imx8_soc_init(void)
> > goto free_rev;
> > }
> >
> > - of_node_put(root);
> > -
> > if (IS_ENABLED(CONFIG_ARM_IMX_CPUFREQ_DT))
> > platform_device_register_simple("imx-cpufreq-dt", -1, NULL,
> 0);
> >
> > @@ -159,7 +155,6 @@ static int __init imx8_soc_init(void)
> > kfree(soc_dev_attr->revision);
> > free_soc:
> > kfree(soc_dev_attr);
> > - of_node_put(root);
> > return ret;
> > }
> > device_initcall(imx8_soc_init);
> > --
> > 2.7.4
> >