Re: [PATCH 1/1] drm/amdgpu: initialize amdgpu_cgs_acpi_eval_object result value

[Alex Deucher]

On Sat, Jun 18, 2016 at 4:55 PM, Nicolas Iooss
<nicolas.iooss_linux@xxxxxxx> wrote:
> amdgpu_cgs_acpi_eval_object() returned the value of variable "result"
> without initializing it first.
>
> This bug has been found by compiling the kernel with clang.  The
> compiler complained:
>
>     drivers/gpu/drm/amd/amdgpu/amdgpu_cgs.c:972:14: error: variable
>     'result' is used uninitialized whenever 'for' loop exits because its
>     condition is false [-Werror,-Wsometimes-uninitialized]
>             for (i = 0; i < count; i++) {
>                         ^~~~~~~~~
>     drivers/gpu/drm/amd/amdgpu/amdgpu_cgs.c:1011:9: note: uninitialized
>     use occurs here
>             return result;
>                    ^~~~~~
>     drivers/gpu/drm/amd/amdgpu/amdgpu_cgs.c:972:14: note: remove the
>     condition if it is always true
>             for (i = 0; i < count; i++) {
>                         ^~~~~~~~~
>     drivers/gpu/drm/amd/amdgpu/amdgpu_cgs.c:864:12: note: initialize the
>     variable 'result' to silence this warning
>             int result;
>                       ^
>                        = 0
>
> Fixes: 3f1d35a03b3c ("drm/amdgpu: implement new cgs interface for acpi
> function")
> Signed-off-by: Nicolas Iooss <nicolas.iooss_linux@xxxxxxx>
> Cc: stable@xxxxxxxxxxxxxxx

Applied.  thanks!

Alex

> ---
>  drivers/gpu/drm/amd/amdgpu/amdgpu_cgs.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_cgs.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_cgs.c
> index 8943099eb135..cf6f49fc1c75 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_cgs.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_cgs.c
> @@ -909,7 +909,7 @@ static int amdgpu_cgs_acpi_eval_object(struct cgs_device *cgs_device,
>         struct cgs_acpi_method_argument *argument = NULL;
>         uint32_t i, count;
>         acpi_status status;
> -       int result;
> +       int result = 0;
>         uint32_t func_no = 0xFFFFFFFF;
>
>         handle = ACPI_HANDLE(&adev->pdev->dev);
> --
> 2.8.3
>
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