gcc-12 is starting to trickle down to some distros, like Archlinux.
gcc-12 has new warnings, and detects more cases of issues, like new
UAF cases, which is causing build issues in code that was previously
building fine, as reported in #14826:
In file included from sigchain.c:3:
In function 'xrealloc',
inlined from 'sigchain_push.isra' at sigchain.c:26:2:
subcmd-util.h:56:23: error: pointer may be used after 'realloc' [-Werror=use-after-free]
56 | ret = realloc(ptr, size);
| ^~~~~~~~~~~~~~~~~~
subcmd-util.h:52:21: note: call to 'realloc' here
52 | void *ret = realloc(ptr, size);
| ^~~~~~~~~~~~~~~~~~
subcmd-util.h:58:31: error: pointer may be used after 'realloc' [-Werror=use-after-free]
58 | ret = realloc(ptr, 1);
| ^~~~~~~~~~~~~~~
subcmd-util.h:52:21: note: call to 'realloc' here
52 | void *ret = realloc(ptr, size);
| ^~~~~~~~~~~~~~~~~~
In that case, the kernel has already fixed their code, which is part of
5.17:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=52a9dab6d892763b2a8334a568bd4e2c1a6fde66
However, we can't easily carry that patch, because we don't know
whether the kernel the user uses already has the fix or not.
Instead, we can just tell the kernel to disable use of -Werror when
building host tools.
As a consequence, we can drop it from the perf-specific setting.
Fixes: #14826
Reported-by: Anders Pitman <buildroot@apitman.com>
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>
(cherry picked from commit baa55a4e26)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>