[Public]
>From the code, it looks like you want to hold reference to the process to
>ensure that it doesn't get destroyed while sending the fault event to user. If
>that is correct, then your commit message is not reflecting that.
With commit message updated, this patch is Reviewed-by: Harish Kasiviswanathan
<harish.kasiviswanat...@amd.com>
-----Original Message-----
From: amd-gfx <amd-gfx-boun...@lists.freedesktop.org> On Behalf Of Philip Yang
Sent: Tuesday, May 27, 2025 11:35 AM
To: amd-gfx@lists.freedesktop.org
Cc: Kuehling, Felix <felix.kuehl...@amd.com>; Koenig, Christian
<christian.koe...@amd.com>; Yang, Philip <philip.y...@amd.com>
Subject: [PATCH] drm/amdkfd: Fix kfd process ref leaking when userptr unmapping
kfd_lookup_process_by_pid increases process ref, the refcount is
leaking.
Fixes: 7a566d7f56f4 ("amd/amdkfd: Trigger segfault for early userptr
unmmapping")
Signed-off-by: Philip Yang <philip.y...@amd.com>
---
drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
index 260165bbe373..99a32bc9bb89 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
@@ -2563,12 +2563,17 @@ static int update_invalid_user_pages(struct
amdkfd_process_info *process_info,
* from the KFD, trigger a segmentation fault in VM
debug mode.
*/
if (amdgpu_ttm_adev(bo->tbo.bdev)->debug_vm_userptr) {
+ struct kfd_process *p;
+
pr_err("Pid %d unmapped memory before
destroying userptr at GPU addr 0x%llx\n",
pid_nr(process_info->pid), mem->va);
// Send GPU VM fault to user space
-
kfd_signal_vm_fault_event_with_userptr(kfd_lookup_process_by_pid(process_info->pid),
- mem->va);
+ p =
kfd_lookup_process_by_pid(process_info->pid);
+ if (p) {
+
kfd_signal_vm_fault_event_with_userptr(p, mem->va);
+ kfd_unref_process(p);
+ }
}
ret = 0;
--
2.49.0
