diff options
| -rw-r--r-- | arch/arm/kernel/smp.c | 9 | ||||
| -rw-r--r-- | lib/nmi_backtrace.c | 11 |
2 files changed, 19 insertions, 1 deletions
diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c index 7c467c5b048e..b26361355dae 100644 --- a/arch/arm/kernel/smp.c +++ b/arch/arm/kernel/smp.c @@ -749,6 +749,15 @@ core_initcall(register_cpufreq_notifier); static void raise_nmi(cpumask_t *mask) { + /* + * Generate the backtrace directly if we are running in a calling + * context that is not preemptible by the backtrace IPI. Note + * that nmi_cpu_backtrace() automatically removes the current cpu + * from mask. + */ + if (cpumask_test_cpu(smp_processor_id(), mask) && irqs_disabled()) + nmi_cpu_backtrace(NULL); + smp_cross_call(mask, IPI_CPU_BACKTRACE); } diff --git a/lib/nmi_backtrace.c b/lib/nmi_backtrace.c index 88d3d32e5923..6019c53c669e 100644 --- a/lib/nmi_backtrace.c +++ b/lib/nmi_backtrace.c @@ -43,6 +43,12 @@ static void print_seq_line(struct nmi_seq_buf *s, int start, int end) printk("%.*s", (end - start) + 1, buf); } +/* + * When raise() is called it will be is passed a pointer to the + * backtrace_mask. Architectures that call nmi_cpu_backtrace() + * directly from their raise() functions may rely on the mask + * they are passed being updated as a side effect of this call. + */ void nmi_trigger_all_cpu_backtrace(bool include_self, void (*raise)(cpumask_t *mask)) { @@ -149,7 +155,10 @@ bool nmi_cpu_backtrace(struct pt_regs *regs) /* Replace printk to write into the NMI seq */ this_cpu_write(printk_func, nmi_vprintk); pr_warn("NMI backtrace for cpu %d\n", cpu); - show_regs(regs); + if (regs) + show_regs(regs); + else + dump_stack(); this_cpu_write(printk_func, printk_func_save); cpumask_clear_cpu(cpu, to_cpumask(backtrace_mask)); |