diff options
Diffstat (limited to 'arch/powerpc/kernel/stacktrace.c')
| -rw-r--r-- | arch/powerpc/kernel/stacktrace.c | 28 |
1 files changed, 22 insertions, 6 deletions
diff --git a/arch/powerpc/kernel/stacktrace.c b/arch/powerpc/kernel/stacktrace.c index e2c50b55138f..dadcc8bab336 100644 --- a/arch/powerpc/kernel/stacktrace.c +++ b/arch/powerpc/kernel/stacktrace.c @@ -8,6 +8,7 @@ * Copyright 2018 Nick Piggin, Michael Ellerman, IBM Corp. */ +#include <linux/delay.h> #include <linux/export.h> #include <linux/kallsyms.h> #include <linux/module.h> @@ -19,6 +20,7 @@ #include <asm/ptrace.h> #include <asm/processor.h> #include <linux/ftrace.h> +#include <linux/delay.h> #include <asm/kprobes.h> #include <asm/paca.h> @@ -204,17 +206,31 @@ static void handle_backtrace_ipi(struct pt_regs *regs) static void raise_backtrace_ipi(cpumask_t *mask) { + struct paca_struct *p; unsigned int cpu; + u64 delay_us; for_each_cpu(cpu, mask) { - if (cpu == smp_processor_id()) + if (cpu == smp_processor_id()) { handle_backtrace_ipi(NULL); - else - smp_send_safe_nmi_ipi(cpu, handle_backtrace_ipi, 5 * USEC_PER_SEC); - } + continue; + } - for_each_cpu(cpu, mask) { - struct paca_struct *p = paca_ptrs[cpu]; + delay_us = 5 * USEC_PER_SEC; + + if (smp_send_safe_nmi_ipi(cpu, handle_backtrace_ipi, delay_us)) { + // Now wait up to 5s for the other CPU to do its backtrace + while (cpumask_test_cpu(cpu, mask) && delay_us) { + udelay(1); + delay_us--; + } + + // Other CPU cleared itself from the mask + if (delay_us) + continue; + } + + p = paca_ptrs[cpu]; cpumask_clear_cpu(cpu, mask); |