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author | Gustavo A. R. Silva <gustavo@embeddedor.com> | 2020-02-20 07:29:08 -0600 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-02-23 19:18:54 +0100 |
commit | 5979afa2c4d1c8acce28a176ebe27ea13265626a (patch) | |
tree | a4713b48315ba2506284f2e376c65ff0af3c871b /drivers/staging/greybus/audio_apbridgea.h | |
parent | cf7e44daa727bf4868a4b3be380829db52a2762d (diff) | |
download | linux-5979afa2c4d1c8acce28a176ebe27ea13265626a.tar.bz2 |
staging: 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>
Link: https://lore.kernel.org/r/20200220132908.GA30501@embeddedor
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/staging/greybus/audio_apbridgea.h')
-rw-r--r-- | drivers/staging/greybus/audio_apbridgea.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/staging/greybus/audio_apbridgea.h b/drivers/staging/greybus/audio_apbridgea.h index 3f1f4dd2c61a..efec0f815efd 100644 --- a/drivers/staging/greybus/audio_apbridgea.h +++ b/drivers/staging/greybus/audio_apbridgea.h @@ -65,7 +65,7 @@ struct audio_apbridgea_hdr { __u8 type; __le16 i2s_port; - __u8 data[0]; + __u8 data[]; } __packed; struct audio_apbridgea_set_config_request { |