Commit c80e1b62 authored Apr 11, 2016 by Corey Minyard Committed by Ralf Baechle May 09, 2016

MIPS: Fix crash registers on non-crashing CPUs



As part of handling a crash on an SMP system, an IPI is send to
all other CPUs to save their current registers and stop.  It was
using task_pt_regs(current) to get the registers, but that will
only be accurate if the CPU was interrupted running in userland.
Instead allow the architecture to pass in the registers (all
pass NULL now, but allow for the future) and then use get_irq_regs()
which should be accurate as we are in an interrupt.  Fall back to
task_pt_regs(current) if nothing else is available.

Signed-off-by: Corey Minyard <cminyard@mvista.com>
Cc: David Daney <ddaney@caviumnetworks.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13050/


Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

parent e03ac9f0

arch/mips/kernel/crash.c

+13 −3

Original line number	Diff line number	Diff line
		@@ -14,11 +14,21 @@ static int crashing_cpu = -1;
		static cpumask_t cpus_in_crash = CPU_MASK_NONE;

		#ifdef CONFIG_SMP
		static void crash_shutdown_secondary(void *ignore)
		static void crash_shutdown_secondary(void *passed_regs)
		{
		struct pt_regs *regs;
		struct pt_regs *regs = passed_regs;
		int cpu = smp_processor_id();

		/*
		* If we are passed registers, use those. Otherwise get the
		* regs from the last interrupt, which should be correct, as
		* we are in an interrupt. But if the regs are not there,
		* pull them from the top of the stack. They are probably
		* wrong, but we need something to keep from crashing again.
		*/
		if (!regs)
		regs = get_irq_regs();
		if (!regs)
		regs = task_pt_regs(current);

		if (!cpu_online(cpu))

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