diff options
| author | Gustavo A. R. Silva <gustavo@embeddedor.com> | 2020-03-05 05:00:11 -0600 |
|---|---|---|
| committer | Daniel Vetter <daniel.vetter@ffwll.ch> | 2020-03-06 11:52:01 +0100 |
| commit | 78a7b61aefa341db7c55d58a66842c34dd50db6d (patch) | |
| tree | c6adbae951f00659ae9767cda95e8f5011b28bef /include/drm | |
| parent | 5b2adbddf25c3543b265c0b8834a4580b971f71e (diff) | |
| download | linux-78a7b61aefa341db7c55d58a66842c34dd50db6d.tar.bz2 | |
drm/bridge/mhl.h: Replace zero-length array with flexible-array member
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:
struct foo {
int stuff;
struct boo array[];
};
By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.
Also, notice that, dynamic memory allocations won't be affected by
this change:
"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]
This issue was found with the help of Coccinelle.
[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20200305110011.GA21056@embeddedor
Diffstat (limited to 'include/drm')
| -rw-r--r-- | include/drm/bridge/mhl.h | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/include/drm/bridge/mhl.h b/include/drm/bridge/mhl.h index 1cc77bf38324..d96626a0e3fa 100644 --- a/include/drm/bridge/mhl.h +++ b/include/drm/bridge/mhl.h @@ -327,13 +327,13 @@ struct mhl_burst_bits_per_pixel_fmt { struct { u8 stream_id; u8 pixel_format; - } __packed desc[0]; + } __packed desc[]; } __packed; struct mhl_burst_emsc_support { struct mhl3_burst_header hdr; u8 num_entries; - __be16 burst_id[0]; + __be16 burst_id[]; } __packed; struct mhl_burst_audio_descr { |