diff options
| author | Gustavo A. R. Silva <gustavo@embeddedor.com> | 2020-03-05 13:55:58 +0300 |
|---|---|---|
| committer | Hans de Goede <hdegoede@redhat.com> | 2020-03-07 14:55:05 +0300 |
| commit | afdd597940f386eeb03175c98744bdbe622fad7a (patch) | |
| tree | ab7dabbdf326ddf06102efbd297b342626caa6f9 /drivers/gpu/drm/vboxvideo | |
| parent | 7064de726ec800f230733d9d8cccf1266160aabf (diff) | |
| download | linux-afdd597940f386eeb03175c98744bdbe622fad7a.tar.xz | |
drm/vboxvideo/vboxvideo.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>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200305105558.GA19124@embeddedor
Diffstat (limited to 'drivers/gpu/drm/vboxvideo')
| -rw-r--r-- | drivers/gpu/drm/vboxvideo/vboxvideo.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/gpu/drm/vboxvideo/vboxvideo.h b/drivers/gpu/drm/vboxvideo/vboxvideo.h index 0592004f71aa..a5de40fe1a76 100644 --- a/drivers/gpu/drm/vboxvideo/vboxvideo.h +++ b/drivers/gpu/drm/vboxvideo/vboxvideo.h @@ -138,7 +138,7 @@ struct vbva_buffer { u32 data_len; /* variable size for the rest of the vbva_buffer area in VRAM. */ - u8 data[0]; + u8 data[]; } __packed; #define VBVA_MAX_RECORD_SIZE (128 * 1024 * 1024) |