diff options
Diffstat (limited to 'include/linux/kernel.h')
| -rw-r--r-- | include/linux/kernel.h | 28 |
1 files changed, 28 insertions, 0 deletions
diff --git a/include/linux/kernel.h b/include/linux/kernel.h index 350dfb08aee3..7311c3294e25 100644 --- a/include/linux/kernel.h +++ b/include/linux/kernel.h @@ -255,6 +255,7 @@ extern long (*panic_blink)(int state); __printf(1, 2) void panic(const char *fmt, ...) __noreturn __cold; +void nmi_panic_self_stop(struct pt_regs *); extern void oops_enter(void); extern void oops_exit(void); void print_oops_end_marker(void); @@ -446,6 +447,33 @@ extern int sysctl_panic_on_stackoverflow; extern bool crash_kexec_post_notifiers; /* + * panic_cpu is used for synchronizing panic() and crash_kexec() execution. It + * holds a CPU number which is executing panic() currently. A value of + * PANIC_CPU_INVALID means no CPU has entered panic() or crash_kexec(). + */ +extern atomic_t panic_cpu; +#define PANIC_CPU_INVALID -1 + +/* + * A variant of panic() called from NMI context. We return if we've already + * panicked on this CPU. If another CPU already panicked, loop in + * nmi_panic_self_stop() which can provide architecture dependent code such + * as saving register state for crash dump. + */ +#define nmi_panic(regs, fmt, ...) \ +do { \ + int old_cpu, cpu; \ + \ + cpu = raw_smp_processor_id(); \ + old_cpu = atomic_cmpxchg(&panic_cpu, PANIC_CPU_INVALID, cpu); \ + \ + if (old_cpu == PANIC_CPU_INVALID) \ + panic(fmt, ##__VA_ARGS__); \ + else if (old_cpu != cpu) \ + nmi_panic_self_stop(regs); \ +} while (0) + +/* * Only to be used by arch init code. If the user over-wrote the default * CONFIG_PANIC_TIMEOUT, honor it. */ |