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| author | Xiyu Yang <xiyuyang19@fudan.edu.cn> | 2020-06-13 20:28:38 +0800 |
|---|---|---|
| committer | Christian König <christian.koenig@amd.com> | 2020-06-15 10:21:19 +0200 |
| commit | 37cc4b95d13f311c04aa8e9daacca3905ad45ca7 (patch) | |
| tree | a52280817494b5501819c02da9c4247262680901 /drivers/gpu/drm/ttm | |
| parent | abf56fadf0e208abfb13ad1ac0094416058da0ad (diff) | |
| download | lwn-37cc4b95d13f311c04aa8e9daacca3905ad45ca7.tar.gz lwn-37cc4b95d13f311c04aa8e9daacca3905ad45ca7.zip | |
drm/ttm: Fix dma_fence refcnt leak in ttm_bo_vm_fault_reserved
ttm_bo_vm_fault_reserved() invokes dma_fence_get(), which returns a
reference of the specified dma_fence object to "moving" with increased
refcnt.
When ttm_bo_vm_fault_reserved() returns, local variable "moving" becomes
invalid, so the refcount should be decreased to keep refcount balanced.
The reference counting issue happens in several exception handling paths
of ttm_bo_vm_fault_reserved(). When those error scenarios occur such as
"err" equals to -EBUSY, the function forgets to decrease the refcnt
increased by dma_fence_get(), causing a refcnt leak.
Fix this issue by calling dma_fence_put() when no_wait_gpu flag is
equals to true.
Signed-off-by: Xiyu Yang <xiyuyang19@fudan.edu.cn>
Signed-off-by: Xin Tan <tanxin.ctf@gmail.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Link: https://patchwork.freedesktop.org/patch/370219/
Signed-off-by: Christian König <christian.koenig@amd.com>
Diffstat (limited to 'drivers/gpu/drm/ttm')
| -rw-r--r-- | drivers/gpu/drm/ttm/ttm_bo_vm.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/gpu/drm/ttm/ttm_bo_vm.c b/drivers/gpu/drm/ttm/ttm_bo_vm.c index 0ad30b112982..72100b84c7a9 100644 --- a/drivers/gpu/drm/ttm/ttm_bo_vm.c +++ b/drivers/gpu/drm/ttm/ttm_bo_vm.c @@ -300,8 +300,10 @@ vm_fault_t ttm_bo_vm_fault_reserved(struct vm_fault *vmf, break; case -EBUSY: case -ERESTARTSYS: + dma_fence_put(moving); return VM_FAULT_NOPAGE; default: + dma_fence_put(moving); return VM_FAULT_SIGBUS; } |