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| author | Gustavo A. R. Silva <gustavo@embeddedor.com> | 2020-03-05 13:53:06 +0300 |
|---|---|---|
| committer | Daniel Vetter <daniel.vetter@ffwll.ch> | 2020-03-06 13:40:53 +0300 |
| commit | 1895a4fc3fad488038c4cdb4e417361649a61351 (patch) | |
| tree | 41f81ff3fd38be65d6aab3cb52f57caa6808a1b0 /drivers/gpu | |
| parent | 099d705dd161897e98c6d7b99b8ca740f3bc747a (diff) | |
| download | linux-1895a4fc3fad488038c4cdb4e417361649a61351.tar.xz | |
drm/gma500/intel_bios.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/20200305105306.GA18788@embeddedor
Diffstat (limited to 'drivers/gpu')
| -rw-r--r-- | drivers/gpu/drm/gma500/intel_bios.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/gpu/drm/gma500/intel_bios.h b/drivers/gpu/drm/gma500/intel_bios.h index a1f9ce9465a5..0e6facf21e33 100644 --- a/drivers/gpu/drm/gma500/intel_bios.h +++ b/drivers/gpu/drm/gma500/intel_bios.h @@ -227,7 +227,7 @@ struct bdb_general_definitions { * number = (block_size - sizeof(bdb_general_definitions))/ * sizeof(child_device_config); */ - struct child_device_config devices[0]; + struct child_device_config devices[]; }; struct bdb_lvds_options { |