From 856839b76836a2ee524a8638f568275da57f719c Mon Sep 17 00:00:00 2001 From: Eunbong Song Date: Wed, 22 Oct 2014 06:39:56 +0000 Subject: [PATCH] MIPS: Add arch_trigger_all_cpu_backtrace() function Currently, arch_trigger_all_cpu_backtrace() is defined in only x86 and sparc which have an NMI. But in case of softlockup, it could be possible to dump backtrace of all cpus. and this could be helpful for debugging. for example, if system has 2 cpus. CPU 0 CPU 1 acquire read_lock() try to do write_lock() ,,, missing read_unlock() In this case, softlockup will occur becasuse CPU 0 does not call read_unlock(). And dump_stack() print only backtrace for "CPU 0". If CPU1's backtrace is printed it's very helpful. [ralf@linux-mips.org: Fixed whitespace and formatting issues.] Signed-off-by: Ralf Baechle Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/8200/ --- arch/mips/include/asm/irq.h | 3 +++ arch/mips/kernel/process.c | 18 ++++++++++++++++++ 2 files changed, 21 insertions(+) diff --git a/arch/mips/include/asm/irq.h b/arch/mips/include/asm/irq.h index 39f07aec640c..5a4e1bb8fb1b 100644 --- a/arch/mips/include/asm/irq.h +++ b/arch/mips/include/asm/irq.h @@ -48,4 +48,7 @@ extern int cp0_compare_irq; extern int cp0_compare_irq_shift; extern int cp0_perfcount_irq; +void arch_trigger_all_cpu_backtrace(bool); +#define arch_trigger_all_cpu_backtrace arch_trigger_all_cpu_backtrace + #endif /* _ASM_IRQ_H */ diff --git a/arch/mips/kernel/process.c b/arch/mips/kernel/process.c index d0e77b2470cb..eb76434828e8 100644 --- a/arch/mips/kernel/process.c +++ b/arch/mips/kernel/process.c @@ -42,6 +42,7 @@ #include #include #include +#include #ifdef CONFIG_HOTPLUG_CPU void arch_cpu_idle_dead(void) @@ -532,3 +533,20 @@ unsigned long arch_align_stack(unsigned long sp) return sp & ALMASK; } + +static void arch_dump_stack(void *info) +{ + struct pt_regs *regs; + + regs = get_irq_regs(); + + if (regs) + show_regs(regs); + + dump_stack(); +} + +void arch_trigger_all_cpu_backtrace(bool include_self) +{ + smp_call_function(arch_dump_stack, NULL, 1); +}