[PATCH] drm/amdgpu/powerplay/smu7: fix unintialized data usage

[PATCH] drm/amdgpu/powerplay/smu7: fix unintialized data usage

[Arnd Bergmann]

A recent bugfix replaced an out-of-bounds access with direct
use of unintialized data:

drivers/gpu/drm/amd/powerplay/hwmgr/smu7_hwmgr.c: In function 'smu7_patch_limits_vddc':
drivers/gpu/drm/amd/powerplay/hwmgr/smu7_hwmgr.c:2033:6: error: 'vddc' may be used uninitialized in this function [-Werror=maybe-uninitialized]
drivers/gpu/drm/amd/powerplay/hwmgr/smu7_hwmgr.c:2146:11: note: 'vddc' was declared here
drivers/gpu/drm/amd/powerplay/hwmgr/smu7_hwmgr.c:2033:6: error: 'vddci' may be used uninitialized in this function [-Werror=maybe-uninitialized]
drivers/gpu/drm/amd/powerplay/hwmgr/smu7_hwmgr.c:2146:17: note: 'vddci' was declared here
  uint32_t vddc, vddci;

This initializes the data as before using the correct type.

Fixes: 77f7f71f5be1 ("drm/amdgpu/powerplay/smu7: fix static checker warning")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 drivers/gpu/drm/amd/powerplay/hwmgr/smu7_hwmgr.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/gpu/drm/amd/powerplay/hwmgr/smu7_hwmgr.c b/drivers/gpu/drm/amd/powerplay/hwmgr/smu7_hwmgr.c
index 9e49f2777143..b2d61d043d52 100644
--- a/drivers/gpu/drm/amd/powerplay/hwmgr/smu7_hwmgr.c
+++ b/drivers/gpu/drm/amd/powerplay/hwmgr/smu7_hwmgr.c
@@ -2147,9 +2147,11 @@ static int smu7_patch_limits_vddc(struct pp_hwmgr *hwmgr,
 	struct smu7_hwmgr *data = (struct smu7_hwmgr *)(hwmgr->backend);
 
 	if (tab) {
+		vddc = tab->vddc;
 		smu7_patch_ppt_v0_with_vdd_leakage(hwmgr, &vddc,
 						   &data->vddc_leakage);
 		tab->vddc = vddc;
+		vddci = tab->vddci;
 		smu7_patch_ppt_v0_with_vdd_leakage(hwmgr, &vddci,
 						   &data->vddci_leakage);
 		tab->vddci = vddci;
-- 
2.9.0

Re: [PATCH] drm/amdgpu/powerplay/smu7: fix unintialized data usage

[Alex Deucher]

On Tue, Nov 8, 2016 at 8:52 AM, Arnd Bergmann <arnd@arndb.de> wrote:
> A recent bugfix replaced an out-of-bounds access with direct
> use of unintialized data:
>
> drivers/gpu/drm/amd/powerplay/hwmgr/smu7_hwmgr.c: In function 'smu7_patch_limits_vddc':
> drivers/gpu/drm/amd/powerplay/hwmgr/smu7_hwmgr.c:2033:6: error: 'vddc' may be used uninitialized in this function [-Werror=maybe-uninitialized]
> drivers/gpu/drm/amd/powerplay/hwmgr/smu7_hwmgr.c:2146:11: note: 'vddc' was declared here
> drivers/gpu/drm/amd/powerplay/hwmgr/smu7_hwmgr.c:2033:6: error: 'vddci' may be used uninitialized in this function [-Werror=maybe-uninitialized]
> drivers/gpu/drm/amd/powerplay/hwmgr/smu7_hwmgr.c:2146:17: note: 'vddci' was declared here
>   uint32_t vddc, vddci;
>
> This initializes the data as before using the correct type.
>
> Fixes: 77f7f71f5be1 ("drm/amdgpu/powerplay/smu7: fix static checker warning")
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>

Applied.  thanks!

Alex

> ---
>  drivers/gpu/drm/amd/powerplay/hwmgr/smu7_hwmgr.c | 2 ++
>  1 file changed, 2 insertions(+)
>
> diff --git a/drivers/gpu/drm/amd/powerplay/hwmgr/smu7_hwmgr.c b/drivers/gpu/drm/amd/powerplay/hwmgr/smu7_hwmgr.c
> index 9e49f2777143..b2d61d043d52 100644
> --- a/drivers/gpu/drm/amd/powerplay/hwmgr/smu7_hwmgr.c
> +++ b/drivers/gpu/drm/amd/powerplay/hwmgr/smu7_hwmgr.c
> @@ -2147,9 +2147,11 @@ static int smu7_patch_limits_vddc(struct pp_hwmgr *hwmgr,
>         struct smu7_hwmgr *data = (struct smu7_hwmgr *)(hwmgr->backend);
>
>         if (tab) {
> +               vddc = tab->vddc;
>                 smu7_patch_ppt_v0_with_vdd_leakage(hwmgr, &vddc,
>                                                    &data->vddc_leakage);
>                 tab->vddc = vddc;
> +               vddci = tab->vddci;
>                 smu7_patch_ppt_v0_with_vdd_leakage(hwmgr, &vddci,
>                                                    &data->vddci_leakage);
>                 tab->vddci = vddci;
> --
> 2.9.0
>
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