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author | Gustavo A. R. Silva <gustavo@embeddedor.com> | 2020-03-19 16:38:39 -0500 |
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committer | Bjorn Andersson <bjorn.andersson@linaro.org> | 2020-03-25 22:30:46 -0700 |
commit | ef17f5193edd42e8913c93d0b601c101c56a15bb (patch) | |
tree | 5d0b195d9c0f2fc34a9e0b19f0cee152c059033d /lib | |
parent | ffd0bbfb378ecd56eac22bf932ccdbf89ac7f725 (diff) | |
download | linux-ef17f5193edd42e8913c93d0b601c101c56a15bb.tar.bz2 |
hwspinlock: hwspinlock_internal.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")
Reviewed-by: Baolin Wang <baolin.wang7@gmail.com>
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Link: https://lore.kernel.org/r/20200319213839.GA10669@embeddedor.com
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Diffstat (limited to 'lib')
0 files changed, 0 insertions, 0 deletions