From: Hemmo Nieminen Date: Thu, 15 Jan 2015 21:01:59 +0000 (+0200) Subject: MIPS: Fix kernel lockup or crash after CPU offline/online X-Git-Tag: v3.4.107~36 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=db6c390a258149666ccee4a0bea5f8c7acb033bc;p=thirdparty%2Fkernel%2Fstable.git 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: Hemmo Nieminen Signed-off-by: Aaro Koskinen Cc: David Daney 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 [lizf: Backported to 3.4: adjust context] Signed-off-by: Zefan Li --- diff --git a/arch/mips/kernel/smp.c b/arch/mips/kernel/smp.c index ba9376bf52a1e..7c2c1afe73f3d 100644 --- a/arch/mips/kernel/smp.c +++ b/arch/mips/kernel/smp.c @@ -105,10 +105,10 @@ asmlinkage __cpuinit void start_secondary(void) if ((read_c0_tcbind() & TCBIND_CURTC) == 0) #endif /* CONFIG_MIPS_MT_SMTC */ cpu_probe(); - cpu_report(); per_cpu_trap_init(); mips_clockevent_init(); mp_ops->init_secondary(); + cpu_report(); /* * XXX parity protection should be folded in here when it's converted