Re: [PATCH] drm/amdkfd: fix uninitialized variable use

[Oded Gabbay]

On Thu, Mar 15, 2018 at 6:49 PM, Arnd Bergmann <arnd@xxxxxxxx> wrote:
> When CONFIG_ACPI is disabled, we never initialize the acpi_table
> structure in kfd_create_crat_image_virtual:
>
> drivers/gpu/drm/amd/amdkfd/kfd_crat.c: In function 'kfd_create_crat_image_virtual':
> drivers/gpu/drm/amd/amdkfd/kfd_crat.c:888:40: error: 'acpi_table' may be used uninitialized in this function [-Werror=maybe-uninitialized]
>
> The undefined behavior also happens for any other acpi_get_table()
> failure, but then the compiler can't warn about it.
>
> This adds an error check that prevents the structure from
> being used in error, avoiding both the undefined behavior and
> the warning about it.
>
> Fixes: 520b8fb755cc ("drm/amdkfd: Add topology support for CPUs")
> Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
> ---
>  drivers/gpu/drm/amd/amdkfd/kfd_crat.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_crat.c b/drivers/gpu/drm/amd/amdkfd/kfd_crat.c
> index 7493f47e7fe1..d85112224f1d 100644
> --- a/drivers/gpu/drm/amd/amdkfd/kfd_crat.c
> +++ b/drivers/gpu/drm/amd/amdkfd/kfd_crat.c
> @@ -882,7 +882,7 @@ static int kfd_create_vcrat_image_cpu(void *pcrat_image, size_t *size)
>         crat_table->length = sizeof(struct crat_header);
>
>         status = acpi_get_table("DSDT", 0, &acpi_table);
> -       if (status == AE_NOT_FOUND)
> +       if (status != AE_OK)
>                 pr_warn("DSDT table not found for OEM information\n");
>         else {
>                 crat_table->oem_revision = acpi_table->revision;
> --
> 2.9.0
>

Thanks!
Applied to -next
Oded