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| author | Gustavo A. R. Silva <gustavoars@kernel.org> | 2020-05-07 21:20:00 +0200 |
|---|---|---|
| committer | Mauro Carvalho Chehab <mchehab+huawei@kernel.org> | 2020-05-25 15:44:00 +0200 |
| commit | 142d06489fc7952976841ec888a655c3735e66fd (patch) | |
| tree | c7fad3a18c93cbc0d5eb6a57e76d17b6ae61b494 /drivers/media | |
| parent | cd25993988491f97a42b3db490fdb2599c67edc8 (diff) | |
| download | linux-142d06489fc7952976841ec888a655c3735e66fd.tar.bz2 | |
media: s5k5baf: Replace zero-length array with flexible-array
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]
sizeof(flexible-array-member) triggers a warning because flexible array
members have incomplete type[1]. There are some instances of code in
which the sizeof operator is being incorrectly/erroneously applied to
zero-length arrays and the result is zero. Such instances may be hiding
some bugs. So, this work (flexible-array member conversions) will also
help to get completely rid of those sorts of issues.
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 <gustavoars@kernel.org>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Diffstat (limited to 'drivers/media')
| -rw-r--r-- | drivers/media/i2c/s5k5baf.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/media/i2c/s5k5baf.c b/drivers/media/i2c/s5k5baf.c index cdfe008ba39f..42584a088273 100644 --- a/drivers/media/i2c/s5k5baf.c +++ b/drivers/media/i2c/s5k5baf.c @@ -281,7 +281,7 @@ struct s5k5baf_fw { u16 id; u16 offset; } seq[0]; - u16 data[0]; + u16 data[]; }; struct s5k5baf { |