From ceb9a321e7639700844aa3bf234a4e0884f13b77 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Christian=20K=C3=B6nig?= <christian.koenig@amd.com>
Date: Fri, 8 Dec 2023 13:43:09 +0100
Subject: [PATCH] drm/amdgpu: fix tear down order in amdgpu_vm_pt_free
Mime-version: 1.0
Content-type: text/plain; charset=UTF-8
Content-transfer-encoding: 8bit
Git-commit: ceb9a321e7639700844aa3bf234a4e0884f13b77
Patch-mainline: v6.7-rc6
References: git-fixes
When freeing PD/PT with shadows it can happen that the shadow
destruction races with detaching the PD/PT from the VM causing a NULL
pointer dereference in the invalidation code.
Fix this by detaching the the PD/PT from the VM first and then
freeing the shadow instead.
Signed-off-by: Christian König <christian.koenig@amd.com>
Fixes: https://gitlab.freedesktop.org/drm/amd/-/issues/2867
Cc: <stable@vger.kernel.org>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Acked-by: Takashi Iwai <tiwai@suse.de>
---
drivers/gpu/drm/amd/amdgpu/amdgpu_vm_pt.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm_pt.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm_pt.c
index a2287bb25223..a160265ddc07 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm_pt.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm_pt.c
@@ -642,13 +642,14 @@ static void amdgpu_vm_pt_free(struct amdgpu_vm_bo_base *entry)
if (!entry->bo)
return;
+
+ entry->bo->vm_bo = NULL;
shadow = amdgpu_bo_shadowed(entry->bo);
if (shadow) {
ttm_bo_set_bulk_move(&shadow->tbo, NULL);
amdgpu_bo_unref(&shadow);
}
ttm_bo_set_bulk_move(&entry->bo->tbo, NULL);
- entry->bo->vm_bo = NULL;
spin_lock(&entry->vm->status_lock);
list_del(&entry->vm_status);
--
2.35.3