diff options
Diffstat (limited to 'arch/mips/kernel/process.c')
| -rw-r--r-- | arch/mips/kernel/process.c | 43 |
1 files changed, 29 insertions, 14 deletions
diff --git a/arch/mips/kernel/process.c b/arch/mips/kernel/process.c index 8d85046adcc8..9670e70139fd 100644 --- a/arch/mips/kernel/process.c +++ b/arch/mips/kernel/process.c @@ -29,6 +29,7 @@ #include <linux/kallsyms.h> #include <linux/random.h> #include <linux/prctl.h> +#include <linux/nmi.h> #include <asm/asm.h> #include <asm/bootinfo.h> @@ -655,28 +656,42 @@ unsigned long arch_align_stack(unsigned long sp) return sp & ALMASK; } -static void arch_dump_stack(void *info) +static DEFINE_PER_CPU(call_single_data_t, backtrace_csd); +static struct cpumask backtrace_csd_busy; + +static void handle_backtrace(void *info) { - struct pt_regs *regs; + nmi_cpu_backtrace(get_irq_regs()); + cpumask_clear_cpu(smp_processor_id(), &backtrace_csd_busy); +} - regs = get_irq_regs(); +static void raise_backtrace(cpumask_t *mask) +{ + call_single_data_t *csd; + int cpu; - if (regs) - show_regs(regs); + for_each_cpu(cpu, mask) { + /* + * If we previously sent an IPI to the target CPU & it hasn't + * cleared its bit in the busy cpumask then it didn't handle + * our previous IPI & it's not safe for us to reuse the + * call_single_data_t. + */ + if (cpumask_test_and_set_cpu(cpu, &backtrace_csd_busy)) { + pr_warn("Unable to send backtrace IPI to CPU%u - perhaps it hung?\n", + cpu); + continue; + } - dump_stack(); + csd = &per_cpu(backtrace_csd, cpu); + csd->func = handle_backtrace; + smp_call_function_single_async(cpu, csd); + } } void arch_trigger_cpumask_backtrace(const cpumask_t *mask, bool exclude_self) { - long this_cpu = get_cpu(); - - if (cpumask_test_cpu(this_cpu, mask) && !exclude_self) - dump_stack(); - - smp_call_function_many(mask, arch_dump_stack, NULL, 1); - - put_cpu(); + nmi_trigger_cpumask_backtrace(mask, exclude_self, raise_backtrace); } int mips_get_process_fp_mode(struct task_struct *task) |