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| author | Petr Mladek <pmladek@suse.com> | 2021-08-30 16:36:10 +0200 |
|---|---|---|
| committer | Petr Mladek <pmladek@suse.com> | 2021-08-30 16:36:10 +0200 |
| commit | c985aafb60e972c0a6b8d0bd65e03af5890b748a (patch) | |
| tree | fb75c6e5330663eeaff707dee672762e607e2f0b /lib | |
| parent | Merge branch 'rework/fixup-for-5.15' into for-linus (diff) | |
| parent | lib/nmi_backtrace: Serialize even messages about idle CPUs (diff) | |
| download | linux-c985aafb60e972c0a6b8d0bd65e03af5890b748a.tar.xz linux-c985aafb60e972c0a6b8d0bd65e03af5890b748a.zip | |
Merge branch 'rework/printk_safe-removal' into for-linus
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/nmi_backtrace.c | 13 |
1 files changed, 7 insertions, 6 deletions
diff --git a/lib/nmi_backtrace.c b/lib/nmi_backtrace.c index 8abe1870dba4..f9e89001b52e 100644 --- a/lib/nmi_backtrace.c +++ b/lib/nmi_backtrace.c @@ -75,12 +75,6 @@ void nmi_trigger_cpumask_backtrace(const cpumask_t *mask, touch_softlockup_watchdog(); } - /* - * Force flush any remote buffers that might be stuck in IRQ context - * and therefore could not run their irq_work. - */ - printk_safe_flush(); - clear_bit_unlock(0, &backtrace_flag); put_cpu(); } @@ -92,8 +86,14 @@ module_param(backtrace_idle, bool, 0644); bool nmi_cpu_backtrace(struct pt_regs *regs) { int cpu = smp_processor_id(); + unsigned long flags; if (cpumask_test_cpu(cpu, to_cpumask(backtrace_mask))) { + /* + * Allow nested NMI backtraces while serializing + * against other CPUs. + */ + printk_cpu_lock_irqsave(flags); if (!READ_ONCE(backtrace_idle) && regs && cpu_in_idle(instruction_pointer(regs))) { pr_warn("NMI backtrace for cpu %d skipped: idling at %pS\n", cpu, (void *)instruction_pointer(regs)); @@ -104,6 +104,7 @@ bool nmi_cpu_backtrace(struct pt_regs *regs) else dump_stack(); } + printk_cpu_unlock_irqrestore(flags); cpumask_clear_cpu(cpu, to_cpumask(backtrace_mask)); return true; } |