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| author | Zile Xiong <xiongzile99@gmail.com> | 2026-03-20 09:54:45 +0300 |
|---|---|---|
| committer | Hans Verkuil <hverkuil+cisco@kernel.org> | 2026-05-06 10:05:56 +0300 |
| commit | a562d6dc86bdfdd299e1b4734977a8d63e803583 (patch) | |
| tree | 6996bdee1feabcde16ece89ad193d986c4a4a2cf /include | |
| parent | 084973ebd67b28f0945c5d45408f86c58b540110 (diff) | |
| download | linux-a562d6dc86bdfdd299e1b4734977a8d63e803583.tar.xz | |
media: vb2: use ssize_t for vb2_read/vb2_write
vb2_read() and vb2_write() return size_t, but propagate
negative errno values from __vb2_perform_fileio().
This relies on implicit signed/unsigned conversions in callers
(e.g. vb2_fop_read()) to recover error codes:
__vb2_perform_fileio() -> -EINVAL
vb2_read() -> (size_t)-EINVAL
vb2_fop_read() -> -EINVAL
This relies on implicit conversions that are not obvious.
These helpers are exported (EXPORT_SYMBOL_GPL) and part of the
vb2 API, so changing their return type may affect existing users.
However, they conceptually follow read/write semantics, where
ssize_t is typically used to return either a byte count or a
negative error code.
Switch vb2_read() and vb2_write() to ssize_t, and update
__vb2_perform_fileio() accordingly.
Signed-off-by: Zile Xiong <xiongzile99@gmail.com>
Acked-by: Marek Szyprowski <m.szyprowski@samsung.com>
Fixes: b25748fe6126 ("[media] v4l: videobuf2: add read() and write() emulator")
Cc: stable@vger.kernel.org
Signed-off-by: Hans Verkuil <hverkuil+cisco@kernel.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/media/videobuf2-core.h | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/include/media/videobuf2-core.h b/include/media/videobuf2-core.h index 4424d481d7f7..4b4f4c15c53a 100644 --- a/include/media/videobuf2-core.h +++ b/include/media/videobuf2-core.h @@ -1093,8 +1093,8 @@ __poll_t vb2_core_poll(struct vb2_queue *q, struct file *file, * @ppos: file handle position tracking pointer * @nonblock: mode selector (1 means blocking calls, 0 means nonblocking) */ -size_t vb2_read(struct vb2_queue *q, char __user *data, size_t count, - loff_t *ppos, int nonblock); +ssize_t vb2_read(struct vb2_queue *q, char __user *data, size_t count, + loff_t *ppos, int nonblock); /** * vb2_write() - implements write() syscall logic. * @q: pointer to &struct vb2_queue with videobuf2 queue. @@ -1103,8 +1103,8 @@ size_t vb2_read(struct vb2_queue *q, char __user *data, size_t count, * @ppos: file handle position tracking pointer * @nonblock: mode selector (1 means blocking calls, 0 means nonblocking) */ -size_t vb2_write(struct vb2_queue *q, const char __user *data, size_t count, - loff_t *ppos, int nonblock); +ssize_t vb2_write(struct vb2_queue *q, const char __user *data, size_t count, + loff_t *ppos, int nonblock); /** * typedef vb2_thread_fnc - callback function for use with vb2_thread. |