OpenCloudOS-Kernel/drivers/video/fbdev/mmp
Gustavo A. R. Silva 451787d3e2 video: 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 7649773293 ("cxgb3/l2t: Fix undefined behaviour")

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200221160005.GA13552@embeddedor
2020-03-02 16:32:17 +01:00
..
fb video: fbdev: mmp: fix sparse warnings about using incorrect types 2020-01-03 14:27:36 +01:00
hw video: Replace zero-length array with flexible-array member 2020-03-02 16:32:17 +01:00
panel treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 13 2019-05-21 11:28:45 +02:00
Kconfig video: fbdev: mmp: add COMPILE_TEST support 2020-01-03 14:27:35 +01:00
Makefile treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
core.c video: fbdev/mmp/core: Use struct_size() in kzalloc() 2019-08-19 15:52:28 +02:00