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-rw-r--r--arch/mips/kernel/process.c45
1 files changed, 30 insertions, 15 deletions
diff --git a/arch/mips/kernel/process.c b/arch/mips/kernel/process.c
index d4cfeb931382..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)
-{
- struct pt_regs *regs;
+static DEFINE_PER_CPU(call_single_data_t, backtrace_csd);
+static struct cpumask backtrace_csd_busy;
- regs = get_irq_regs();
-
- if (regs)
- show_regs(regs);
- else
- dump_stack();
+static void handle_backtrace(void *info)
+{
+ nmi_cpu_backtrace(get_irq_regs());
+ cpumask_clear_cpu(smp_processor_id(), &backtrace_csd_busy);
}
-void arch_trigger_cpumask_backtrace(const cpumask_t *mask, bool exclude_self)
+static void raise_backtrace(cpumask_t *mask)
{
- long this_cpu = get_cpu();
+ call_single_data_t *csd;
+ int cpu;
- if (cpumask_test_cpu(this_cpu, mask) && !exclude_self)
- dump_stack();
+ 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;
+ }
- smp_call_function_many(mask, arch_dump_stack, NULL, 1);
+ csd = &per_cpu(backtrace_csd, cpu);
+ csd->func = handle_backtrace;
+ smp_call_function_single_async(cpu, csd);
+ }
+}
- put_cpu();
+void arch_trigger_cpumask_backtrace(const cpumask_t *mask, bool exclude_self)
+{
+ nmi_trigger_cpumask_backtrace(mask, exclude_self, raise_backtrace);
}
int mips_get_process_fp_mode(struct task_struct *task)