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List:       linux-mips-cvs
Subject:    MIPS: Fix kernel lockup or crash after CPU offline/online
From:       linux-mips () linux-mips ! org
Date:       2015-01-30 1:10:18
Message-ID: S27012279AbbA3BKVeZD3F/20150130011021Z+318 () eddie ! linux-mips ! org
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Author: Hemmo Nieminen <hemmo.nieminen@iki.fi> Thu Jan 15 23:01:59 2015 +0200
Comitter: Ralf Baechle <ralf@linux-mips.org> Fri Jan 30 00:14:52 2015 +0100
Commit: 112d676c8fccbb2fd08cc4b5f57fe277e3c21546
Gitweb: http://git.linux-mips.org/g/ralf/linux/112d676c8fcc
Branch: linux-2.6.25-stable

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@iki.fi>
Signed-off-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Cc: stable@vger.kernel.org
Cc: David Daney <david.daney@cavium.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/8953/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
(cherry picked from commit e997a190728b3607eef062fdbfe21852ed10e977)

---

 arch/mips/kernel/smp.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

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