diff options
| author | Tomer Tayar <tomer.tayar@intel.com> | 2024-07-25 11:39:58 +0300 |
|---|---|---|
| committer | Koby Elbaz <koby.elbaz@intel.com> | 2025-09-25 09:09:27 +0300 |
| commit | d0dd796becb08b164fb2d791dca4a76127b3e89a (patch) | |
| tree | 281b361c20cf4b6ebf90e9086ce419a5c52360fc | |
| parent | b5cddeb0dc6521dfee669e74967c6d28b1fd0d9e (diff) | |
accel/habanalabs: clarify ctx use after hl_ctx_put() in dmabuf release
In hl_release_dmabuf(), ctx is dereferenced after calling hl_ctx_put()
to obtain the compute device file.
This is safe because the dma-buf object holds a file reference taken in
export_dmabuf(), and the file release (which drops another ctx reference)
can only happen after we drop that file reference via fput(). Thus, this
hl_ctx_put() call cannot be the last one at this point.
Add a comment explaining this to avoid confusion.
Signed-off-by: Tomer Tayar <tomer.tayar@intel.com>
Reviewed-by: Koby Elbaz <koby.elbaz@intel.com>
Signed-off-by: Koby Elbaz <koby.elbaz@intel.com>
| -rw-r--r-- | drivers/accel/habanalabs/common/memory.c | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/drivers/accel/habanalabs/common/memory.c b/drivers/accel/habanalabs/common/memory.c index 48d2d598a387..633db4bff46f 100644 --- a/drivers/accel/habanalabs/common/memory.c +++ b/drivers/accel/habanalabs/common/memory.c @@ -1837,7 +1837,12 @@ static void hl_release_dmabuf(struct dma_buf *dmabuf) atomic_dec(&ctx->hdev->dmabuf_export_cnt); hl_ctx_put(ctx); - /* Paired with get_file() in export_dmabuf() */ + /* + * Paired with get_file() in export_dmabuf(). + * 'ctx' can be still used here to get the file pointer, even after hl_ctx_put() was called, + * because releasing the compute device file involves another reference decrement, and it + * would be possible only after calling fput(). + */ fput(ctx->hpriv->file_priv->filp); kfree(hl_dmabuf); |