This is a note to let you know that I've just added the patch titled
drm/xe: Fix ref counting leak on page fault
to the 6.8-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
drm-xe-fix-ref-counting-leak-on-page-fault.patch
and it can be found in the queue-6.8 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 0d2787720de8f3b02a0d0b66679fc8e1ecc76337
Author: Matthew Brost <matthew.brost@xxxxxxxxx>
Date: Thu Feb 29 20:10:36 2024 -0800
drm/xe: Fix ref counting leak on page fault
[ Upstream commit f7da398935f7ddabf1a098714593e032c875cd74 ]
If a page fault occurs on VM not in fault a ref can be leaked. Fix this.
Fixes: dd08ebf6c352 ("drm/xe: Introduce a new DRM driver for Intel GPUs")
Signed-off-by: Matthew Brost <matthew.brost@xxxxxxxxx>
Reviewed-by: Mika Kuoppala <mika.kuoppala@xxxxxxxxxxxxxxx>
Link: https://patchwork.freedesktop.org/patch/msgid/20240301041036.238471-1-matthew.brost@xxxxxxxxx
(cherry picked from commit 27b5a3f237fe66dbf2288c2b50973aee8a427e41)
Signed-off-by: Lucas De Marchi <lucas.demarchi@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/gpu/drm/xe/xe_gt_pagefault.c b/drivers/gpu/drm/xe/xe_gt_pagefault.c
index 73f08f1924df2..e2cf1759527c6 100644
--- a/drivers/gpu/drm/xe/xe_gt_pagefault.c
+++ b/drivers/gpu/drm/xe/xe_gt_pagefault.c
@@ -146,10 +146,12 @@ static int handle_pagefault(struct xe_gt *gt, struct pagefault *pf)
/* ASID to VM */
mutex_lock(&xe->usm.lock);
vm = xa_load(&xe->usm.asid_to_vm, pf->asid);
- if (vm)
+ if (vm && xe_vm_in_fault_mode(vm))
xe_vm_get(vm);
+ else
+ vm = NULL;
mutex_unlock(&xe->usm.lock);
- if (!vm || !xe_vm_in_fault_mode(vm))
+ if (!vm)
return -EINVAL;
retry_userptr:
