From a2305e3de819394a7adf68078964a92d06f9db33 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Thu, 29 Apr 2021 10:06:38 +0200 Subject: powerpc: mark local variables around longjmp as volatile 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] According to the documentation, marking these as 'volatile' is sufficient to avoid the problem, and it shuts up the warning. Signed-off-by: Arnd Bergmann Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20210429080708.1520360-1-arnd@kernel.org --- arch/powerpc/kexec/crash.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'arch/powerpc/kexec') diff --git a/arch/powerpc/kexec/crash.c b/arch/powerpc/kexec/crash.c index 0196d0c211ac..10f997e6bb95 100644 --- a/arch/powerpc/kexec/crash.c +++ b/arch/powerpc/kexec/crash.c @@ -105,8 +105,8 @@ void crash_ipi_callback(struct pt_regs *regs) static void crash_kexec_prepare_cpus(int cpu) { unsigned int msecs; - unsigned int ncpus = num_online_cpus() - 1;/* Excluding the panic cpu */ - int tries = 0; + volatile unsigned int ncpus = num_online_cpus() - 1;/* Excluding the panic cpu */ + volatile int tries = 0; int (*old_handler)(struct pt_regs *regs); printk(KERN_EMERG "Sending IPI to other CPUs\n"); -- cgit v1.2.3