[PATCH v2] drm/i915/gt: Use kmemdup_array instead of kmemdup for multiple allocation

[PATCH v2] drm/i915/gt: Use kmemdup_array instead of kmemdup for multiple allocation

[Yu Jiaoliang]

Let the kememdup_array() take care about multiplication and possible
overflows.

v2:
- Change subject
- Leave one blank line between the commit log and the tag section
- Fix code alignment issue

Signed-off-by: Yu Jiaoliang <yujiaoliang@vivo.com>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Andi Shyti <andi.shyti@linux.intel.com>
---
 drivers/gpu/drm/i915/gt/intel_workarounds.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/i915/gt/intel_workarounds.c b/drivers/gpu/drm/i915/gt/intel_workarounds.c
index d90348c56765..0fcfd55c62b4 100644
--- a/drivers/gpu/drm/i915/gt/intel_workarounds.c
+++ b/drivers/gpu/drm/i915/gt/intel_workarounds.c
@@ -111,9 +111,8 @@ static void wa_init_finish(struct i915_wa_list *wal)
 {
 	/* Trim unused entries. */
 	if (!IS_ALIGNED(wal->count, WA_LIST_CHUNK)) {
-		struct i915_wa *list = kmemdup_array(wal->list,
-					       wal->count, sizeof(*list),
-					       GFP_KERNEL);
+		struct i915_wa *list = kmemdup_array(wal->list, wal->count,
+											 sizeof(*list), GFP_KERNEL);
 
 		if (list) {
 			kfree(wal->list);
-- 
2.34.1

Re: [PATCH v2] drm/i915/gt: Use kmemdup_array instead of kmemdup for multiple allocation

[Andi Shyti]

Hi,

On Tue, Aug 20, 2024 at 05:53:02PM +0800, Yu Jiaoliang wrote:
> Let the kememdup_array() take care about multiplication and possible
> overflows.
> 
> v2:
> - Change subject
> - Leave one blank line between the commit log and the tag section
> - Fix code alignment issue
> 
> Signed-off-by: Yu Jiaoliang <yujiaoliang@vivo.com>
> Reviewed-by: Jani Nikula <jani.nikula@intel.com>
> Reviewed-by: Andi Shyti <andi.shyti@linux.intel.com>

I didn't give you an explicit R-b, but that's fine, you can keep
it as I think the patch is fine.

> -		struct i915_wa *list = kmemdup_array(wal->list,
> -					       wal->count, sizeof(*list),
> -					       GFP_KERNEL);
> +		struct i915_wa *list = kmemdup_array(wal->list, wal->count,
> +											 sizeof(*list), GFP_KERNEL);

Do you see the indentation is off here? :-)

Please, run checkpatch.pl before sending the patch, as well.

Besides, what patch is this? Are you replacing kmemdup_array with
kmemdup_array? This v2 applies on your v1 while it should apply
on a clean drm-tip repository.

Thanks,
Andi

>  
>  		if (list) {
>  			kfree(wal->list);
> -- 
> 2.34.1

Re: [PATCH v2] drm/i915/gt: Use kmemdup_array instead of kmemdup for multiple allocation

[Lucas De Marchi]

On Tue, Aug 20, 2024 at 05:53:02PM GMT, Yu Jiaoliang wrote:
>Let the kememdup_array() take care about multiplication and possible
>overflows.
>
>v2:
>- Change subject
>- Leave one blank line between the commit log and the tag section
>- Fix code alignment issue
>
>Signed-off-by: Yu Jiaoliang <yujiaoliang@vivo.com>
>Reviewed-by: Jani Nikula <jani.nikula@intel.com>
>Reviewed-by: Andi Shyti <andi.shyti@linux.intel.com>
>---
> drivers/gpu/drm/i915/gt/intel_workarounds.c | 5 ++---
> 1 file changed, 2 insertions(+), 3 deletions(-)
>
>diff --git a/drivers/gpu/drm/i915/gt/intel_workarounds.c b/drivers/gpu/drm/i915/gt/intel_workarounds.c
>index d90348c56765..0fcfd55c62b4 100644
>--- a/drivers/gpu/drm/i915/gt/intel_workarounds.c
>+++ b/drivers/gpu/drm/i915/gt/intel_workarounds.c
>@@ -111,9 +111,8 @@ static void wa_init_finish(struct i915_wa_list *wal)
> {
> 	/* Trim unused entries. */
> 	if (!IS_ALIGNED(wal->count, WA_LIST_CHUNK)) {
>-		struct i915_wa *list = kmemdup_array(wal->list,

					^

it was already kmemdup_array, not kmemdup. Am I missing anything?

Lucas De Marchi

>-					       wal->count, sizeof(*list),
>-					       GFP_KERNEL);
>+		struct i915_wa *list = kmemdup_array(wal->list, wal->count,
>+											 sizeof(*list), GFP_KERNEL);
>
> 		if (list) {
> 			kfree(wal->list);
>-- 
>2.34.1
>

Re: [PATCH v2] drm/i915/gt: Use kmemdup_array instead of kmemdup for multiple allocation

[Andi Shyti]

Hi Lucas,

On Tue, Aug 20, 2024 at 07:53:10AM -0500, Lucas De Marchi wrote:
> On Tue, Aug 20, 2024 at 05:53:02PM GMT, Yu Jiaoliang wrote:
> > Let the kememdup_array() take care about multiplication and possible
> > overflows.
> > 
> > v2:
> > - Change subject
> > - Leave one blank line between the commit log and the tag section
> > - Fix code alignment issue
> > 
> > Signed-off-by: Yu Jiaoliang <yujiaoliang@vivo.com>
> > Reviewed-by: Jani Nikula <jani.nikula@intel.com>
> > Reviewed-by: Andi Shyti <andi.shyti@linux.intel.com>
> > ---
> > drivers/gpu/drm/i915/gt/intel_workarounds.c | 5 ++---
> > 1 file changed, 2 insertions(+), 3 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/i915/gt/intel_workarounds.c b/drivers/gpu/drm/i915/gt/intel_workarounds.c
> > index d90348c56765..0fcfd55c62b4 100644
> > --- a/drivers/gpu/drm/i915/gt/intel_workarounds.c
> > +++ b/drivers/gpu/drm/i915/gt/intel_workarounds.c
> > @@ -111,9 +111,8 @@ static void wa_init_finish(struct i915_wa_list *wal)
> > {
> > 	/* Trim unused entries. */
> > 	if (!IS_ALIGNED(wal->count, WA_LIST_CHUNK)) {
> > -		struct i915_wa *list = kmemdup_array(wal->list,
> 
> 					^
> 
> it was already kmemdup_array, not kmemdup. Am I missing anything?

I see kmemdup() in drm-tip.

What Yu has done here is to change kmemdup to kmemdup_array and
send the patch. Received the reviews and made a new commit on top
of the previous one; then he sent only this second commit.

Yu needs to make sure that:

 1. the patch applies correctly on a clean drm-tip
 2. drm-tip + patch compiles
 3. there are no checkpatch and sparse new errors

We missed point 1 here :-)

Andi