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| author | Christian König <christian.koenig@amd.com> | 2022-01-19 13:40:21 +0300 |
|---|---|---|
| committer | Christian König <christian.koenig@amd.com> | 2022-02-08 11:20:09 +0300 |
| commit | 0fd9803b985e5d94e2b9f1848a12756b7848b62d (patch) | |
| tree | f7eeab2f2bfe1114b2695c73fb174bb02ee7af28 /drivers/dma-buf | |
| parent | 976b6d97c62347df3e686f60a5f455bb8ed6ea23 (diff) | |
| download | linux-0fd9803b985e5d94e2b9f1848a12756b7848b62d.tar.xz | |
dma-buf: warn about dma_fence_array container rules v2
It's not allowed to nest another dma_fence container into a dma_fence_array
or otherwise we can run into recursion.
Warn about that when we create a dma_fence_array.
v2: fix comment style and typo in the warning pointed out by Thomas
Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220204100429.2049-3-christian.koenig@amd.com
Diffstat (limited to 'drivers/dma-buf')
| -rw-r--r-- | drivers/dma-buf/dma-fence-array.c | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/drivers/dma-buf/dma-fence-array.c b/drivers/dma-buf/dma-fence-array.c index 3e07f961e2f3..cb1bacb5a42b 100644 --- a/drivers/dma-buf/dma-fence-array.c +++ b/drivers/dma-buf/dma-fence-array.c @@ -176,6 +176,20 @@ struct dma_fence_array *dma_fence_array_create(int num_fences, array->base.error = PENDING_ERROR; + /* + * dma_fence_array objects should never contain any other fence + * containers or otherwise we run into recursion and potential kernel + * stack overflow on operations on the dma_fence_array. + * + * The correct way of handling this is to flatten out the array by the + * caller instead. + * + * Enforce this here by checking that we don't create a dma_fence_array + * with any container inside. + */ + while (num_fences--) + WARN_ON(dma_fence_is_container(fences[num_fences])); + return array; } EXPORT_SYMBOL(dma_fence_array_create); |