summaryrefslogtreecommitdiff
path: root/arch
diff options
context:
space:
mode:
authorCorey Minyard <cminyard@mvista.com>2016-04-11 09:10:19 -0500
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2017-05-08 07:44:08 +0200
commitad6cff92b69f68bdc48be347b93f2f2f32044e98 (patch)
tree15d51b1eb7401f6735a2cfd105925a08f6fd4cdd /arch
parent6541ad80d598cc810de25af437317b6e93a07232 (diff)
MIPS: Fix crash registers on non-crashing CPUs
commit c80e1b62ffca52e2d1d865ee58bc79c4c0c55005 upstream. 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> Cc: Julia Lawall <julia.lawall@lip6.fr> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch')
-rw-r--r--arch/mips/kernel/crash.c16
1 files changed, 13 insertions, 3 deletions
diff --git a/arch/mips/kernel/crash.c b/arch/mips/kernel/crash.c
index d21264681e97..26c7786d1407 100644
--- a/arch/mips/kernel/crash.c
+++ b/arch/mips/kernel/crash.c
@@ -14,12 +14,22 @@ 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();
- regs = task_pt_regs(current);
+ /*
+ * 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))
return;