On Fri, Nov 15, 2024 at 10:49:42AM +0800, Su Hui wrote:
> Clang static checker(scan-build) warning：
> drivers/gpu/drm/xe/xe_hw_engine_group.c: line 134, column 2
> Argument to kfree() is a constant address (18446744073709551604), which
> is not memory allocated by malloc().
>
> kfree() can only handle NULL pointers instead of negitave error codes.
> When hw_engine_group_alloc() failed, there is a bad kfree call for
> negitave error codes in xe_hw_engine_setup_groups().
>
> Free 'group' when alloc_workqueue() failed in hw_engine_group_alloc(), and
> remove wrong kfree() in xe_hw_engine_setup_groups() to fix this problem.
> It's safe to remove these kfree() because drmm_add_action_or_reset()
> can free these by calling hw_engine_group_free().
>
> Fixes: d16ef1a18e39 ("drm/xe/exec: Switch hw engine group execution mode upon job submission")
> Fixes: f784750c670f ("drm/xe/hw_engine_group: Introduce xe_hw_engine_group")
> Signed-off-by: Su Hui <suhui@xxxxxxxxxxxx>
Thanks for thr fix. Look correct to me.
Reviewed-by: Matthew Brost <matthew.brost@xxxxxxxxx>
> ---
> v2:
> - remove wrong destroy_workqueue() and kfree() in v1 patch
> v1:
> - https://lore.kernel.org/all/20241114063942.3448607-1-suhui@xxxxxxxxxxxx/
>
> drivers/gpu/drm/xe/xe_hw_engine_group.c | 32 +++++++------------------
> 1 file changed, 9 insertions(+), 23 deletions(-)
>
> diff --git a/drivers/gpu/drm/xe/xe_hw_engine_group.c b/drivers/gpu/drm/xe/xe_hw_engine_group.c
> index 82750520a90a..3bfa002734ad 100644
> --- a/drivers/gpu/drm/xe/xe_hw_engine_group.c
> +++ b/drivers/gpu/drm/xe/xe_hw_engine_group.c
> @@ -58,8 +58,10 @@ hw_engine_group_alloc(struct xe_device *xe)
> return ERR_PTR(-ENOMEM);
>
> group->resume_wq = alloc_workqueue("xe-resume-lr-jobs-wq", 0, 0);
> - if (!group->resume_wq)
> + if (!group->resume_wq) {
> + kfree(group);
> return ERR_PTR(-ENOMEM);
> + }
>
> init_rwsem(&group->mode_sem);
> INIT_WORK(&group->resume_work, hw_engine_group_resume_lr_jobs_func);
> @@ -84,25 +86,18 @@ int xe_hw_engine_setup_groups(struct xe_gt *gt)
> enum xe_hw_engine_id id;
> struct xe_hw_engine_group *group_rcs_ccs, *group_bcs, *group_vcs_vecs;
> struct xe_device *xe = gt_to_xe(gt);
> - int err;
>
> group_rcs_ccs = hw_engine_group_alloc(xe);
> - if (IS_ERR(group_rcs_ccs)) {
> - err = PTR_ERR(group_rcs_ccs);
> - goto err_group_rcs_ccs;
> - }
> + if (IS_ERR(group_rcs_ccs))
> + return PTR_ERR(group_rcs_ccs);
>
> group_bcs = hw_engine_group_alloc(xe);
> - if (IS_ERR(group_bcs)) {
> - err = PTR_ERR(group_bcs);
> - goto err_group_bcs;
> - }
> + if (IS_ERR(group_bcs))
> + return PTR_ERR(group_bcs);
>
> group_vcs_vecs = hw_engine_group_alloc(xe);
> - if (IS_ERR(group_vcs_vecs)) {
> - err = PTR_ERR(group_vcs_vecs);
> - goto err_group_vcs_vecs;
> - }
> + if (IS_ERR(group_vcs_vecs))
> + return PTR_ERR(group_vcs_vecs);
>
> for_each_hw_engine(hwe, gt, id) {
> switch (hwe->class) {
> @@ -125,15 +120,6 @@ int xe_hw_engine_setup_groups(struct xe_gt *gt)
> }
>
> return 0;
> -
> -err_group_vcs_vecs:
> - kfree(group_vcs_vecs);
> -err_group_bcs:
> - kfree(group_bcs);
> -err_group_rcs_ccs:
> - kfree(group_rcs_ccs);
> -
> - return err;
> }
>
> /**
> --
> 2.30.2
>
