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Commit 69ab8e5c authored by Hemmo Nieminen's avatar Hemmo Nieminen Committed by Greg Kroah-Hartman
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MIPS: Fix kernel lockup or crash after CPU offline/online 



commit c7754e75100ed5e3068ac5085747f2bfc386c8d6 upstream.

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: default avatarHemmo Nieminen <hemmo.nieminen@iki.fi>
Signed-off-by: default avatarAaro Koskinen <aaro.koskinen@iki.fi>
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: default avatarRalf Baechle <ralf@linux-mips.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent a88c24fa

arch/mips/kernel/smp.c

+1 −1
Original line number Diff line number Diff line
@@ -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