[Intel-xe] [PATCH 1/2] drm/xe: Fix uninitialized variables

[Matt Roper]

On Tue, May 23, 2023 at 03:50:19PM +0200, Michał Winiarski wrote:
> From: Michał Winiarski <michal.winiarski at intel.com>
> 
> Using uninitialized variables leads to undefined behavior.
> 
> Moreover, it causes the compiler to complain with:
> ../drivers/gpu/drm/xe/xe_vm.c:3265:40: error: variable 'vma' is uninitialized when used here [-Werror,-Wuninitialized]
> ../drivers/gpu/drm/xe/xe_rtp.c:118:36: error: variable 'i' is uninitialized when used here [-Werror,-Wuninitialized]
> ../drivers/gpu/drm/xe/xe_mocs.c:449:3: error: variable 'flags' is uninitialized when used here [-Werror,-Wuninitialized]
> 
> Signed-off-by: Michał Winiarski <michal.winiarski at intel.com>

Reviewed-by: Matt Roper <matthew.d.roper at intel.com>

> ---
>  drivers/gpu/drm/xe/xe_mocs.c | 2 +-
>  drivers/gpu/drm/xe/xe_rtp.c  | 2 +-
>  drivers/gpu/drm/xe/xe_vm.c   | 2 +-
>  3 files changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/gpu/drm/xe/xe_mocs.c b/drivers/gpu/drm/xe/xe_mocs.c
> index c7a9e733ef3b..ec82088b73f0 100644
> --- a/drivers/gpu/drm/xe/xe_mocs.c
> +++ b/drivers/gpu/drm/xe/xe_mocs.c
> @@ -373,7 +373,7 @@ static const struct xe_mocs_entry mtl_mocs_desc[] = {
>  static unsigned int get_mocs_settings(struct xe_device *xe,
>  				      struct xe_mocs_info *info)
>  {
> -	unsigned int flags;
> +	unsigned int flags = 0;
>  
>  	memset(info, 0, sizeof(struct xe_mocs_info));
>  
> diff --git a/drivers/gpu/drm/xe/xe_rtp.c b/drivers/gpu/drm/xe/xe_rtp.c
> index 0c6a23e14a71..86fd1025b931 100644
> --- a/drivers/gpu/drm/xe/xe_rtp.c
> +++ b/drivers/gpu/drm/xe/xe_rtp.c
> @@ -115,7 +115,7 @@ static void rtp_process_one(const struct xe_rtp_entry *entry, struct xe_gt *gt,
>  	if (!rule_matches(gt, hwe, entry))
>  		return;
>  
> -	for (action = &entry->actions[0]; i < entry->n_actions; action++, i++) {
> +	for (i = 0, action = &entry->actions[0]; i < entry->n_actions; action++, i++) {
>  		if ((entry->flags & XE_RTP_ENTRY_FLAG_FOREACH_ENGINE) ||
>  		    (action->flags & XE_RTP_ACTION_FLAG_ENGINE_BASE))
>  			mmio_base = hwe->mmio_base;
> diff --git a/drivers/gpu/drm/xe/xe_vm.c b/drivers/gpu/drm/xe/xe_vm.c
> index a0306526b269..109a5d93be89 100644
> --- a/drivers/gpu/drm/xe/xe_vm.c
> +++ b/drivers/gpu/drm/xe/xe_vm.c
> @@ -3262,7 +3262,7 @@ int xe_vm_bind_ioctl(struct drm_device *dev, void *data, struct drm_file *file)
>  		if (!vmas[i])
>  			break;
>  
> -		list_for_each_entry_safe(vma, next, &vma->unbind_link,
> +		list_for_each_entry_safe(vma, next, &vmas[i]->unbind_link,
>  					 unbind_link) {
>  			list_del_init(&vma->unbind_link);
>  			if (!vma->destroyed) {
> -- 
> 2.40.1
> 

-- 
Matt Roper
Graphics Software Engineer
Linux GPU Platform Enablement
Intel Corporation