[PATCH v2 2/2] MIPS: fix kernel lockup or crash after CPU offline/online
From: Aaro Koskinen
Date: Thu Jan 15 2015 - 16:03:01 EST
From: Hemmo Nieminen <hemmo.nieminen@xxxxxx>
As printk() invocation can cause e.g. a TLB miss, printk() cannot be
called before the exception handlers have been properly initialized.
This can happen e.g. when netconsole has been loaded as a kernel module
and the TLB table has been cleared when a CPU was offline.
Call cpu_report() in start_secondary() only after the exception handlers
have been initialized to fix this.
Without the patch the kernel will randomly either lockup or crash
after a CPU is onlined and the console driver is a module.
Signed-off-by: Hemmo Nieminen <hemmo.nieminen@xxxxxx>
Signed-off-by: Aaro Koskinen <aaro.koskinen@xxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
---
v2: No changes in this patch.
v1: http://marc.info/?l=linux-mips&m=142134783418176&w=2
arch/mips/kernel/smp.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/mips/kernel/smp.c b/arch/mips/kernel/smp.c
index c94c4e9..1c0d8c5 100644
--- a/arch/mips/kernel/smp.c
+++ b/arch/mips/kernel/smp.c
@@ -123,10 +123,10 @@ asmlinkage void start_secondary(void)
unsigned int cpu;
cpu_probe();
- cpu_report();
per_cpu_trap_init(false);
mips_clockevent_init();
mp_ops->init_secondary();
+ cpu_report();
/*
* XXX parity protection should be folded in here when it's converted
--
2.2.0
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