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author | Gustavo A. R. Silva <gustavo@embeddedor.com> | 2020-03-05 13:51:37 +0300 |
---|---|---|
committer | Lucas Stach <l.stach@pengutronix.de> | 2020-03-05 14:15:46 +0300 |
commit | 1442d81fef9955f362ed64b3da7a9d885cd09205 (patch) | |
tree | f8ae865272e60e3f07838274fe9fd4b5013b06e8 /drivers/gpu/drm/etnaviv | |
parent | 78f2bfa3181cd7ee134274aa17177dd933c69dc1 (diff) | |
download | linux-1442d81fef9955f362ed64b3da7a9d885cd09205.tar.xz |
drm/etnaviv: 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: Lucas Stach <l.stach@pengutronix.de>
Diffstat (limited to 'drivers/gpu/drm/etnaviv')
-rw-r--r-- | drivers/gpu/drm/etnaviv/etnaviv_gem.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/gpu/drm/etnaviv/etnaviv_gem.h b/drivers/gpu/drm/etnaviv/etnaviv_gem.h index 6b68fe16041b..98e60df882b6 100644 --- a/drivers/gpu/drm/etnaviv/etnaviv_gem.h +++ b/drivers/gpu/drm/etnaviv/etnaviv_gem.h @@ -105,7 +105,7 @@ struct etnaviv_gem_submit { unsigned int nr_pmrs; struct etnaviv_perfmon_request *pmrs; unsigned int nr_bos; - struct etnaviv_gem_submit_bo bos[0]; + struct etnaviv_gem_submit_bo bos[]; /* No new members here, the previous one is variable-length! */ }; |