From 2ffdaafb5d5f37bf66da1b775333a7abc2b69563 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Christian=20K=C3=B6nig?= <christian.koenig@amd.com>
Date: Fri, 27 Jan 2017 15:58:43 +0100
Subject: [PATCH] drm/amdgpu: fix race in GEM VA map IOCTL v2
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Somebody could try to free the bo_va between mapping and updating it.
v2: fix typos in comment
Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Nicolai Hähnle <nicolai.haehnle@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
---
drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c | 47 ++++++++-----------------
1 file changed, 15 insertions(+), 32 deletions(-)
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c
index 9bd1b4eae32e..4acb9c5e8b64 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c
@@ -487,67 +487,50 @@ static int amdgpu_gem_va_check(void *param, struct amdgpu_bo *bo)
*
* @adev: amdgpu_device pointer
* @bo_va: bo_va to update
+ * @list: validation list
+ * @operation: map or unmap
*
- * Update the bo_va directly after setting it's address. Errors are not
+ * Update the bo_va directly after setting its address. Errors are not
* vital here, so they are not reported back to userspace.
*/
static void amdgpu_gem_va_update_vm(struct amdgpu_device *adev,
struct amdgpu_bo_va *bo_va,
+ struct list_head *list,
uint32_t operation)
{
- struct ttm_validate_buffer tv, *entry;
- struct amdgpu_bo_list_entry vm_pd;
- struct ww_acquire_ctx ticket;
- struct list_head list, duplicates;
- int r;
+ struct ttm_validate_buffer *entry;
+ int r = -ERESTARTSYS;
- INIT_LIST_HEAD(&list);
- INIT_LIST_HEAD(&duplicates);
-
- tv.bo = &bo_va->bo->tbo;
- tv.shared = true;
- list_add(&tv.head, &list);
-
- amdgpu_vm_get_pd_bo(bo_va->vm, &list, &vm_pd);
-
- /* Provide duplicates to avoid -EALREADY */
- r = ttm_eu_reserve_buffers(&ticket, &list, true, &duplicates);
- if (r)
- goto error_print;
-
- list_for_each_entry(entry, &list, head) {
+ list_for_each_entry(entry, list, head) {
struct amdgpu_bo *bo =
container_of(entry->bo, struct amdgpu_bo, tbo);
/* if anything is swapped out don't swap it in here,
just abort and wait for the next CS */
if (!amdgpu_bo_gpu_accessible(bo))
- goto error_unreserve;
+ goto error;
if (bo->shadow && !amdgpu_bo_gpu_accessible(bo->shadow))
- goto error_unreserve;
+ goto error;
}
r = amdgpu_vm_validate_pt_bos(adev, bo_va->vm, amdgpu_gem_va_check,
NULL);
if (r)
- goto error_unreserve;
+ goto error;
r = amdgpu_vm_update_page_directory(adev, bo_va->vm);
if (r)
- goto error_unreserve;
+ goto error;
r = amdgpu_vm_clear_freed(adev, bo_va->vm);
if (r)
- goto error_unreserve;
+ goto error;
if (operation == AMDGPU_VA_OP_MAP)
r = amdgpu_vm_bo_update(adev, bo_va, false);
-error_unreserve:
- ttm_eu_backoff_reservation(&ticket, &list);
-
-error_print:
+error:
if (r && r != -ERESTARTSYS)
DRM_ERROR("Couldn't update BO_VA (%d)\n", r);
}
@@ -640,10 +623,10 @@ int amdgpu_gem_va_ioctl(struct drm_device *dev, void *data,
default:
break;
}
- ttm_eu_backoff_reservation(&ticket, &list);
if (!r && !(args->flags & AMDGPU_VM_DELAY_UPDATE) &&
!amdgpu_vm_debug)
- amdgpu_gem_va_update_vm(adev, bo_va, args->operation);
+ amdgpu_gem_va_update_vm(adev, bo_va, &list, args->operation);
+ ttm_eu_backoff_reservation(&ticket, &list);
drm_gem_object_unreference_unlocked(gobj);
return r;