linux/fs/pstore
Gustavo A. R. Silva 8128d3aac0 pstore/ram: 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>
Link: https://lore.kernel.org/r/20200309202327.GA8813@embeddedor
Signed-off-by: Kees Cook <keescook@chromium.org>
2020-03-09 14:45:40 -07:00
..
ftrace.c pstore: no need to check return value of debugfs_create functions 2019-07-08 21:04:42 -07:00
inode.c pstore: pstore_ftrace_seq_next should increase position index 2020-02-27 08:04:59 -08:00
internal.h pstore: Centralize init/exit routines 2018-10-22 07:11:58 -07:00
Kconfig treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
Makefile License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
platform.c pstore/platform: fix potential mem leak if pstore_init_fs failed 2020-02-25 11:13:18 -08:00
pmsg.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 282 2019-06-05 17:36:37 +02:00
ram_core.c pstore/ram: Replace zero-length array with flexible-array member 2020-03-09 14:45:40 -07:00
ram.c pstore/ram: remove unnecessary ramoops_unregister_dummy() 2020-02-25 11:15:53 -08:00