drm/i915 target adds some extra cflags, especially it does re-apply -Wall.
In clang this will override -Wno-format-security and cause the build to
fail when CONFIG_DRM_I915_WERROR=y. While with GCC this does not happen.
We reapply -Wno-format-security here to get around this issue.
drivers/gpu/drm/i915/gt/intel_gt.c:983:2: error: format string is not a string literal (potentially insecure) [-Werror,-Wformat-security]
GEM_TRACE("ERROR\n");
^~~~~~~~~~~~~~~~~~~~
./drivers/gpu/drm/i915/i915_gem.h:76:24: note: expanded from macro 'GEM_TRACE'
#define GEM_TRACE(...) trace_printk(__VA_ARGS__)
^~~~~~~~~~~~~~~~~~~~~~~~~
./include/linux/kernel.h:369:3: note: expanded from macro 'trace_printk'
do_trace_printk(fmt, ##__VA_ARGS__); \
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
./include/linux/kernel.h:383:30: note: expanded from macro 'do_trace_printk'
__trace_bprintk(_THIS_IP_, trace_printk_fmt, ##args); \
^~~~~~~~~~~~~~~~
drivers/gpu/drm/i915/gt/intel_gt.c:983:2: note: treat the string as an argument to avoid this
Signed-off-by: Tong Zhang <[email protected]>
---
drivers/gpu/drm/i915/Makefile | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/gpu/drm/i915/Makefile b/drivers/gpu/drm/i915/Makefile
index 1b62b9f65196..c04e05a3d39f 100644
--- a/drivers/gpu/drm/i915/Makefile
+++ b/drivers/gpu/drm/i915/Makefile
@@ -13,6 +13,7 @@
# will most likely get a sudden build breakage... Hopefully we will fix
# new warnings before CI updates!
subdir-ccflags-y := -Wall -Wextra
+subdir-ccflags-y += -Wno-format-security
subdir-ccflags-y += -Wno-unused-parameter
subdir-ccflags-y += -Wno-type-limits
subdir-ccflags-y += -Wno-missing-field-initializers
--
2.25.1
On Sat, Feb 12, 2022 at 10:51:06PM -0800, Tong Zhang wrote:
> drm/i915 target adds some extra cflags, especially it does re-apply -Wall.
> In clang this will override -Wno-format-security and cause the build to
> fail when CONFIG_DRM_I915_WERROR=y. While with GCC this does not happen.
> We reapply -Wno-format-security here to get around this issue.
For what it's worth, GCC would warn in the exact same way if
-Wformat-security was included within -Wall like it is for clang:
drivers/gpu/drm/i915/gt/intel_gt.c: In function ‘intel_gt_invalidate_tlbs’:
drivers/gpu/drm/i915/gt/intel_gt.c:988:9: error: format not a string literal and no format arguments [-Werror=format-security]
988 | GEM_TRACE("\n");
| ^~~~~~~~~
cc1: all warnings being treated as errors
drivers/gpu/drm/i915/gt/selftest_execlists.c: In function ‘live_sanitycheck’:
drivers/gpu/drm/i915/gt/selftest_execlists.c:142:25: error: format not a string literal and no format arguments [-Werror=format-security]
142 | GEM_TRACE("spinner failed to start\n");
| ^~~~~~~~~
drivers/gpu/drm/i915/gt/selftest_execlists.c: In function ‘live_preempt’:
drivers/gpu/drm/i915/gt/selftest_execlists.c:1775:25: error: format not a string literal and no format arguments [-Werror=format-security]
1775 | GEM_TRACE("lo spinner failed to start\n");
| ^~~~~~~~~
drivers/gpu/drm/i915/gt/selftest_execlists.c:1792:25: error: format not a string literal and no format arguments [-Werror=format-security]
1792 | GEM_TRACE("hi spinner failed to start\n");
| ^~~~~~~~~
cc1: all warnings being treated as errors
If fixing these warnings instead of just disabling the warning is
undesirable (since I feel like the entire point of the i195 cflags
situation is to enable more warnings than the main Makefile), I think
the commit message should be rewritten to something along the lines of:
"drm/i915 adds some extra cflags, namely -Wall, which causes
instances of -Wformat-security to appear when building with clang, even
though this warning is turned off kernel-wide in the main Makefile:"
> drivers/gpu/drm/i915/gt/intel_gt.c:983:2: error: format string is not a string literal (potentially insecure) [-Werror,-Wformat-security]
> GEM_TRACE("ERROR\n");
> ^~~~~~~~~~~~~~~~~~~~
> ./drivers/gpu/drm/i915/i915_gem.h:76:24: note: expanded from macro 'GEM_TRACE'
> #define GEM_TRACE(...) trace_printk(__VA_ARGS__)
> ^~~~~~~~~~~~~~~~~~~~~~~~~
> ./include/linux/kernel.h:369:3: note: expanded from macro 'trace_printk'
> do_trace_printk(fmt, ##__VA_ARGS__); \
> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> ./include/linux/kernel.h:383:30: note: expanded from macro 'do_trace_printk'
> __trace_bprintk(_THIS_IP_, trace_printk_fmt, ##args); \
> ^~~~~~~~~~~~~~~~
> drivers/gpu/drm/i915/gt/intel_gt.c:983:2: note: treat the string as an argument to avoid this
"This does not happen with GCC because it does not enable
-Wformat-security with -Wall. Disable -Wformat-security within the i915
Makefile so that these warnings do not show up with clang."
The actual diff itself looks fine to me.
Cheers,
Nathan
> Signed-off-by: Tong Zhang <[email protected]>
> ---
> drivers/gpu/drm/i915/Makefile | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/drivers/gpu/drm/i915/Makefile b/drivers/gpu/drm/i915/Makefile
> index 1b62b9f65196..c04e05a3d39f 100644
> --- a/drivers/gpu/drm/i915/Makefile
> +++ b/drivers/gpu/drm/i915/Makefile
> @@ -13,6 +13,7 @@
> # will most likely get a sudden build breakage... Hopefully we will fix
> # new warnings before CI updates!
> subdir-ccflags-y := -Wall -Wextra
> +subdir-ccflags-y += -Wno-format-security
> subdir-ccflags-y += -Wno-unused-parameter
> subdir-ccflags-y += -Wno-type-limits
> subdir-ccflags-y += -Wno-missing-field-initializers
> --
> 2.25.1
>
On Sun, Feb 13, 2022 at 10:39 AM Nathan Chancellor <[email protected]> wrote:
>
> On Sat, Feb 12, 2022 at 10:51:06PM -0800, Tong Zhang wrote:
> > drm/i915 target adds some extra cflags, especially it does re-apply -Wall.
> > In clang this will override -Wno-format-security and cause the build to
> > fail when CONFIG_DRM_I915_WERROR=y. While with GCC this does not happen.
> > We reapply -Wno-format-security here to get around this issue.
>
> For what it's worth, GCC would warn in the exact same way if
> -Wformat-security was included within -Wall like it is for clang:
>
> drivers/gpu/drm/i915/gt/intel_gt.c: In function ‘intel_gt_invalidate_tlbs’:
> drivers/gpu/drm/i915/gt/intel_gt.c:988:9: error: format not a string literal and no format arguments [-Werror=format-security]
> 988 | GEM_TRACE("\n");
> | ^~~~~~~~~
> cc1: all warnings being treated as errors
>
> drivers/gpu/drm/i915/gt/selftest_execlists.c: In function ‘live_sanitycheck’:
> drivers/gpu/drm/i915/gt/selftest_execlists.c:142:25: error: format not a string literal and no format arguments [-Werror=format-security]
> 142 | GEM_TRACE("spinner failed to start\n");
> | ^~~~~~~~~
> drivers/gpu/drm/i915/gt/selftest_execlists.c: In function ‘live_preempt’:
> drivers/gpu/drm/i915/gt/selftest_execlists.c:1775:25: error: format not a string literal and no format arguments [-Werror=format-security]
> 1775 | GEM_TRACE("lo spinner failed to start\n");
> | ^~~~~~~~~
> drivers/gpu/drm/i915/gt/selftest_execlists.c:1792:25: error: format not a string literal and no format arguments [-Werror=format-security]
> 1792 | GEM_TRACE("hi spinner failed to start\n");
> | ^~~~~~~~~
> cc1: all warnings being treated as errors
>
> If fixing these warnings instead of just disabling the warning is
> undesirable (since I feel like the entire point of the i195 cflags
> situation is to enable more warnings than the main Makefile), I think
> the commit message should be rewritten to something along the lines of:
>
> "drm/i915 adds some extra cflags, namely -Wall, which causes
> instances of -Wformat-security to appear when building with clang, even
> though this warning is turned off kernel-wide in the main Makefile:"
>
> > drivers/gpu/drm/i915/gt/intel_gt.c:983:2: error: format string is not a string literal (potentially insecure) [-Werror,-Wformat-security]
> > GEM_TRACE("ERROR\n");
> > ^~~~~~~~~~~~~~~~~~~~
> > ./drivers/gpu/drm/i915/i915_gem.h:76:24: note: expanded from macro 'GEM_TRACE'
> > #define GEM_TRACE(...) trace_printk(__VA_ARGS__)
> > ^~~~~~~~~~~~~~~~~~~~~~~~~
> > ./include/linux/kernel.h:369:3: note: expanded from macro 'trace_printk'
> > do_trace_printk(fmt, ##__VA_ARGS__); \
> > ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> > ./include/linux/kernel.h:383:30: note: expanded from macro 'do_trace_printk'
> > __trace_bprintk(_THIS_IP_, trace_printk_fmt, ##args); \
> > ^~~~~~~~~~~~~~~~
> > drivers/gpu/drm/i915/gt/intel_gt.c:983:2: note: treat the string as an argument to avoid this
>
> "This does not happen with GCC because it does not enable
> -Wformat-security with -Wall. Disable -Wformat-security within the i915
> Makefile so that these warnings do not show up with clang."
>
> The actual diff itself looks fine to me.
>
> Cheers,
> Nathan
>
> > Signed-off-by: Tong Zhang <[email protected]>
> > ---
> > drivers/gpu/drm/i915/Makefile | 1 +
> > 1 file changed, 1 insertion(+)
> >
> > diff --git a/drivers/gpu/drm/i915/Makefile b/drivers/gpu/drm/i915/Makefile
> > index 1b62b9f65196..c04e05a3d39f 100644
> > --- a/drivers/gpu/drm/i915/Makefile
> > +++ b/drivers/gpu/drm/i915/Makefile
> > @@ -13,6 +13,7 @@
> > # will most likely get a sudden build breakage... Hopefully we will fix
> > # new warnings before CI updates!
> > subdir-ccflags-y := -Wall -Wextra
> > +subdir-ccflags-y += -Wno-format-security
> > subdir-ccflags-y += -Wno-unused-parameter
> > subdir-ccflags-y += -Wno-type-limits
> > subdir-ccflags-y += -Wno-missing-field-initializers
> > --
> > 2.25.1
> >
Thank you Nathan!
I will send a v2 with a revised commit message.
Thanks,
- Tong
drm/i915 adds some extra cflags, namely -Wall, which causes
instances of -Wformat-security to appear when building with clang, even
though this warning is turned off kernel-wide in the main Makefile:
> drivers/gpu/drm/i915/gt/intel_gt.c:983:2: error: format string is not a string literal (potentially insecure) [-Werror,-Wformat-security]
> GEM_TRACE("ERROR\n");
> ^~~~~~~~~~~~~~~~~~~~
> ./drivers/gpu/drm/i915/i915_gem.h:76:24: note: expanded from macro 'GEM_TRACE'
> #define GEM_TRACE(...) trace_printk(__VA_ARGS__)
> ^~~~~~~~~~~~~~~~~~~~~~~~~
> ./include/linux/kernel.h:369:3: note: expanded from macro 'trace_printk'
> do_trace_printk(fmt, ##__VA_ARGS__); \
> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> ./include/linux/kernel.h:383:30: note: expanded from macro 'do_trace_printk'
> __trace_bprintk(_THIS_IP_, trace_printk_fmt, ##args); \
> ^~~~~~~~~~~~~~~~
>drivers/gpu/drm/i915/gt/intel_gt.c:983:2: note: treat the string as an argument to avoid this
This does not happen with GCC because it does not enable
-Wformat-security with -Wall. Disable -Wformat-security within the i915
Makefile so that these warnings do not show up with clang.
Signed-off-by: Tong Zhang <[email protected]>
---
v2: revise commit message
drivers/gpu/drm/i915/Makefile | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/gpu/drm/i915/Makefile b/drivers/gpu/drm/i915/Makefile
index 1b62b9f65196..c04e05a3d39f 100644
--- a/drivers/gpu/drm/i915/Makefile
+++ b/drivers/gpu/drm/i915/Makefile
@@ -13,6 +13,7 @@
# will most likely get a sudden build breakage... Hopefully we will fix
# new warnings before CI updates!
subdir-ccflags-y := -Wall -Wextra
+subdir-ccflags-y += -Wno-format-security
subdir-ccflags-y += -Wno-unused-parameter
subdir-ccflags-y += -Wno-type-limits
subdir-ccflags-y += -Wno-missing-field-initializers
--
2.25.1
On Mon, Feb 14, 2022 at 11:58:20AM -0800, Tong Zhang wrote:
> drm/i915 adds some extra cflags, namely -Wall, which causes
> instances of -Wformat-security to appear when building with clang, even
> though this warning is turned off kernel-wide in the main Makefile:
>
> > drivers/gpu/drm/i915/gt/intel_gt.c:983:2: error: format string is not a string literal (potentially insecure) [-Werror,-Wformat-security]
> > GEM_TRACE("ERROR\n");
> > ^~~~~~~~~~~~~~~~~~~~
> > ./drivers/gpu/drm/i915/i915_gem.h:76:24: note: expanded from macro 'GEM_TRACE'
> > #define GEM_TRACE(...) trace_printk(__VA_ARGS__)
> > ^~~~~~~~~~~~~~~~~~~~~~~~~
> > ./include/linux/kernel.h:369:3: note: expanded from macro 'trace_printk'
> > do_trace_printk(fmt, ##__VA_ARGS__); \
> > ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> > ./include/linux/kernel.h:383:30: note: expanded from macro 'do_trace_printk'
> > __trace_bprintk(_THIS_IP_, trace_printk_fmt, ##args); \
> > ^~~~~~~~~~~~~~~~
> >drivers/gpu/drm/i915/gt/intel_gt.c:983:2: note: treat the string as an argument to avoid this
>
> This does not happen with GCC because it does not enable
> -Wformat-security with -Wall. Disable -Wformat-security within the i915
> Makefile so that these warnings do not show up with clang.
>
> Signed-off-by: Tong Zhang <[email protected]>
Given this is not enabled for GCC and it is disabled in the main
Makefile:
Reviewed-by: Nathan Chancellor <[email protected]>
Additionally, it seems like trace_printk() is designed to be able to
take a string literal without a format argument, so this should be fine.
> ---
>
> v2: revise commit message
>
> drivers/gpu/drm/i915/Makefile | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/drivers/gpu/drm/i915/Makefile b/drivers/gpu/drm/i915/Makefile
> index 1b62b9f65196..c04e05a3d39f 100644
> --- a/drivers/gpu/drm/i915/Makefile
> +++ b/drivers/gpu/drm/i915/Makefile
> @@ -13,6 +13,7 @@
> # will most likely get a sudden build breakage... Hopefully we will fix
> # new warnings before CI updates!
> subdir-ccflags-y := -Wall -Wextra
> +subdir-ccflags-y += -Wno-format-security
> subdir-ccflags-y += -Wno-unused-parameter
> subdir-ccflags-y += -Wno-type-limits
> subdir-ccflags-y += -Wno-missing-field-initializers
> --
> 2.25.1
>
>
On Tue, 15 Feb 2022, Nathan Chancellor <[email protected]> wrote:
> On Mon, Feb 14, 2022 at 11:58:20AM -0800, Tong Zhang wrote:
>> drm/i915 adds some extra cflags, namely -Wall, which causes
>> instances of -Wformat-security to appear when building with clang, even
>> though this warning is turned off kernel-wide in the main Makefile:
>>
>> > drivers/gpu/drm/i915/gt/intel_gt.c:983:2: error: format string is not a string literal (potentially insecure) [-Werror,-Wformat-security]
>> > GEM_TRACE("ERROR\n");
>> > ^~~~~~~~~~~~~~~~~~~~
>> > ./drivers/gpu/drm/i915/i915_gem.h:76:24: note: expanded from macro 'GEM_TRACE'
>> > #define GEM_TRACE(...) trace_printk(__VA_ARGS__)
>> > ^~~~~~~~~~~~~~~~~~~~~~~~~
>> > ./include/linux/kernel.h:369:3: note: expanded from macro 'trace_printk'
>> > do_trace_printk(fmt, ##__VA_ARGS__); \
>> > ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>> > ./include/linux/kernel.h:383:30: note: expanded from macro 'do_trace_printk'
>> > __trace_bprintk(_THIS_IP_, trace_printk_fmt, ##args); \
>> > ^~~~~~~~~~~~~~~~
>> >drivers/gpu/drm/i915/gt/intel_gt.c:983:2: note: treat the string as an argument to avoid this
>>
>> This does not happen with GCC because it does not enable
>> -Wformat-security with -Wall. Disable -Wformat-security within the i915
>> Makefile so that these warnings do not show up with clang.
>>
>> Signed-off-by: Tong Zhang <[email protected]>
>
> Given this is not enabled for GCC and it is disabled in the main
> Makefile:
>
> Reviewed-by: Nathan Chancellor <[email protected]>
>
> Additionally, it seems like trace_printk() is designed to be able to
> take a string literal without a format argument, so this should be fine.
Thanks for the patch and review, pushed to drm-intel-next. I appreciate
the support in maintaining fairly strict warning levels in i915.
BR,
Jani.
>
>> ---
>>
>> v2: revise commit message
>>
>> drivers/gpu/drm/i915/Makefile | 1 +
>> 1 file changed, 1 insertion(+)
>>
>> diff --git a/drivers/gpu/drm/i915/Makefile b/drivers/gpu/drm/i915/Makefile
>> index 1b62b9f65196..c04e05a3d39f 100644
>> --- a/drivers/gpu/drm/i915/Makefile
>> +++ b/drivers/gpu/drm/i915/Makefile
>> @@ -13,6 +13,7 @@
>> # will most likely get a sudden build breakage... Hopefully we will fix
>> # new warnings before CI updates!
>> subdir-ccflags-y := -Wall -Wextra
>> +subdir-ccflags-y += -Wno-format-security
>> subdir-ccflags-y += -Wno-unused-parameter
>> subdir-ccflags-y += -Wno-type-limits
>> subdir-ccflags-y += -Wno-missing-field-initializers
>> --
>> 2.25.1
>>
>>
--
Jani Nikula, Intel Open Source Graphics Center