[PATCH] drm/amd/pm/swsmu: Avoid using structure_size uninitialized in smu_cmn_init_soft_gpu_metrics

[Nathan Chancellor]

Clang warns:

drivers/gpu/drm/amd/amdgpu/../pm/swsmu/smu_cmn.c:764:2: warning:
variable 'structure_size' is used uninitialized whenever switch default
is taken [-Wsometimes-uninitialized]
default:
^~~~~~~
drivers/gpu/drm/amd/amdgpu/../pm/swsmu/smu_cmn.c:770:23: note:
uninitialized use occurs here
memset(header, 0xFF, structure_size);
^~~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/../pm/swsmu/smu_cmn.c:753:25: note:
initialize the variable 'structure_size' to silence this warning
uint16_t structure_size;
^
= 0
1 warning generated.

Return in the default case, as the size of the header will not be known.

Fixes: de4b7cd8cb87 ("drm/amd/pm/swsmu: unify the init soft gpu metrics function")
Link: https://github.com/ClangBuiltLinux/linux/issues/1304
Signed-off-by: Nathan Chancellor <nat...@kernel.org>
---
drivers/gpu/drm/amd/pm/swsmu/smu_cmn.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/pm/swsmu/smu_cmn.c b/drivers/gpu/drm/amd/pm/swsmu/smu_cmn.c
index bb620fdd4cd2..bcedd4d92e35 100644
--- a/drivers/gpu/drm/amd/pm/swsmu/smu_cmn.c
+++ b/drivers/gpu/drm/amd/pm/swsmu/smu_cmn.c
@@ -762,7 +762,7 @@ void smu_cmn_init_soft_gpu_metrics(void *table, uint8_t frev, uint8_t crev)
structure_size = sizeof(struct gpu_metrics_v2_0);
break;
default:
- break;
+ return;
}

#undef METRICS_VERSION
--
2.30.1

[Wang, Kevin(Yang)]

thanks,

Reviewed-by: Kevin Wang <kevin...@amd.com>

Regards,
Kevin

> 在 2021年2月19日，06:49，Nathan Chancellor <nat...@kernel.org> 写道：
>
> Clang warns:

[Alex Deucher]

Applied. Thanks!

Alex

> _______________________________________________
> amd-gfx mailing list
> amd...@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/amd-gfx

[Sedat Dilek]

On Thu, Feb 18, 2021 at 11:49 PM Nathan Chancellor <nat...@kernel.org> wrote:
>
> Clang warns:
>
> drivers/gpu/drm/amd/amdgpu/../pm/swsmu/smu_cmn.c:764:2: warning:
> variable 'structure_size' is used uninitialized whenever switch default
> is taken [-Wsometimes-uninitialized]
> default:
> ^~~~~~~
> drivers/gpu/drm/amd/amdgpu/../pm/swsmu/smu_cmn.c:770:23: note:
> uninitialized use occurs here
> memset(header, 0xFF, structure_size);
> ^~~~~~~~~~~~~~
> drivers/gpu/drm/amd/amdgpu/../pm/swsmu/smu_cmn.c:753:25: note:
> initialize the variable 'structure_size' to silence this warning
> uint16_t structure_size;
> ^
> = 0
> 1 warning generated.
>
> Return in the default case, as the size of the header will not be known.
>
> Fixes: de4b7cd8cb87 ("drm/amd/pm/swsmu: unify the init soft gpu metrics function")
> Link: https://github.com/ClangBuiltLinux/linux/issues/1304
> Signed-off-by: Nathan Chancellor <nat...@kernel.org>

I fell over this today with Linux v5.11-10201-gc03c21ba6f4e.

Tested-by: Sedat Dilek <sedat...@gmail.com> # LLVM/Clang v13-git

- Sedat -

> ---
> drivers/gpu/drm/amd/pm/swsmu/smu_cmn.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/amd/pm/swsmu/smu_cmn.c b/drivers/gpu/drm/amd/pm/swsmu/smu_cmn.c
> index bb620fdd4cd2..bcedd4d92e35 100644
> --- a/drivers/gpu/drm/amd/pm/swsmu/smu_cmn.c
> +++ b/drivers/gpu/drm/amd/pm/swsmu/smu_cmn.c
> @@ -762,7 +762,7 @@ void smu_cmn_init_soft_gpu_metrics(void *table, uint8_t frev, uint8_t crev)
> structure_size = sizeof(struct gpu_metrics_v2_0);
> break;
> default:
> - break;
> + return;
> }
>
> #undef METRICS_VERSION
> --
> 2.30.1
>

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