https://github.com/torvalds/linux
Revision 43951585e1308b322c8ee31a4aafd08213f5c5d7 authored by Gustavo A. R. Silva on 24 March 2020, 00:41:14 UTC, committed by Gustavo A. R. Silva on 18 April 2020, 20:44:56 UTC
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>
1 parent 6e88abb
Tip revision: 43951585e1308b322c8ee31a4aafd08213f5c5d7 authored by Gustavo A. R. Silva on 24 March 2020, 00:41:14 UTC
xattr.h: Replace zero-length array with flexible-array member
xattr.h: Replace zero-length array with flexible-array member
Tip revision: 4395158
| File | Mode | Size |
|---|---|---|
| Documentation | ||
| LICENSES | ||
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | -rw-r--r-- | 15.5 KB |
| .cocciconfig | -rw-r--r-- | 59 bytes |
| .get_maintainer.ignore | -rw-r--r-- | 71 bytes |
| .gitattributes | -rw-r--r-- | 62 bytes |
| .gitignore | -rw-r--r-- | 1.7 KB |
| .mailmap | -rw-r--r-- | 15.1 KB |
| COPYING | -rw-r--r-- | 496 bytes |
| CREDITS | -rw-r--r-- | 97.4 KB |
| Kbuild | -rw-r--r-- | 1.3 KB |
| Kconfig | -rw-r--r-- | 595 bytes |
| MAINTAINERS | -rw-r--r-- | 538.9 KB |
| Makefile | -rw-r--r-- | 59.9 KB |
| README | -rw-r--r-- | 727 bytes |
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