Re: [PATCH] powerpc: mark local variables around longjmp as volatile

[Michael Ellerman]

On Thu, 29 Apr 2021 10:06:38 +0200, Arnd Bergmann wrote:
> gcc-11 points out that modifying local variables next to a
> longjmp/setjmp may cause undefined behavior:
> 
> arch/powerpc/kexec/crash.c: In function 'crash_kexec_prepare_cpus.constprop':
> arch/powerpc/kexec/crash.c:108:22: error: variable 'ncpus' might be clobbered by 'longjmp' or 'vfork' [-Werror=clobbere
> d]
> arch/powerpc/kexec/crash.c:109:13: error: variable 'tries' might be clobbered by 'longjmp' or 'vfork' [-Werror=clobbere
> d]
> arch/powerpc/xmon/xmon.c: In function 'xmon_print_symbol':
> arch/powerpc/xmon/xmon.c:3625:21: error: variable 'name' might be clobbered by 'longjmp' or 'vfork' [-Werror=clobbered]
> arch/powerpc/xmon/xmon.c: In function 'stop_spus':
> arch/powerpc/xmon/xmon.c:4057:13: error: variable 'i' might be clobbered by 'longjmp' or 'vfork' [-Werror=clobbered]
> arch/powerpc/xmon/xmon.c: In function 'restart_spus':
> arch/powerpc/xmon/xmon.c:4098:13: error: variable 'i' might be clobbered by 'longjmp' or 'vfork' [-Werror=clobbered]
> arch/powerpc/xmon/xmon.c: In function 'dump_opal_msglog':
> arch/powerpc/xmon/xmon.c:3008:16: error: variable 'pos' might be clobbered by 'longjmp' or 'vfork' [-Werror=clobbered]
> arch/powerpc/xmon/xmon.c: In function 'show_pte':
> arch/powerpc/xmon/xmon.c:3207:29: error: variable 'tsk' might be clobbered by 'longjmp' or 'vfork' [-Werror=clobbered]
> arch/powerpc/xmon/xmon.c: In function 'show_tasks':
> arch/powerpc/xmon/xmon.c:3302:29: error: variable 'tsk' might be clobbered by 'longjmp' or 'vfork' [-Werror=clobbered]
> arch/powerpc/xmon/xmon.c: In function 'xmon_core':
> arch/powerpc/xmon/xmon.c:494:13: error: variable 'cmd' might be clobbered by 'longjmp' or 'vfork' [-Werror=clobbered]
> arch/powerpc/xmon/xmon.c:860:21: error: variable 'bp' might be clobbered by 'longjmp' or 'vfork' [-Werror=clobbered]
> arch/powerpc/xmon/xmon.c:860:21: error: variable 'bp' might be clobbered by 'longjmp' or 'vfork' [-Werror=clobbered]
> arch/powerpc/xmon/xmon.c:492:48: error: argument 'fromipi' might be clobbered by 'longjmp' or 'vfork' [-Werror=clobbered]
> 
> [...]

Applied to powerpc/next.

[1/1] powerpc: mark local variables around longjmp as volatile
      https://git.kernel.org/powerpc/c/a2305e3de819394a7adf68078964a92d06f9db33

cheers