path: root/include/linux
diff options
authorTakao Indoh <indou.takao@jp.fujitsu.com>2011-03-29 12:35:04 -0400
committerIngo Molnar <mingo@elte.hu>2011-06-17 10:17:12 +0200
commitd8ad7d1123a960cc9f276bd499f9325c6f5e1bd1 (patch)
tree0260df1b5b5b1601f56229c7dde54594d2dfebcb /include/linux
parenteb96c925152fc289311e5d7e956b919e9b60ab53 (diff)
generic-ipi: Fix kexec boot crash by initializing call_single_queue before enabling interrupts
There is a problem that kdump(2nd kernel) sometimes hangs up due to a pending IPI from 1st kernel. Kernel panic occurs because IPI comes before call_single_queue is initialized. To fix the crash, rename init_call_single_data() to call_function_init() and call it in start_kernel() so that call_single_queue can be initialized before enabling interrupts. The details of the crash are: (1) 2nd kernel boots up (2) A pending IPI from 1st kernel comes when irqs are first enabled in start_kernel(). (3) Kernel tries to handle the interrupt, but call_single_queue is not initialized yet at this point. As a result, in the generic_smp_call_function_single_interrupt(), NULL pointer dereference occurs when list_replace_init() tries to access &q->list.next. Therefore this patch changes the name of init_call_single_data() to call_function_init() and calls it before local_irq_enable() in start_kernel(). Signed-off-by: Takao Indoh <indou.takao@jp.fujitsu.com> Reviewed-by: WANG Cong <xiyou.wangcong@gmail.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Acked-by: Vivek Goyal <vgoyal@redhat.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Milton Miller <miltonm@bga.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: kexec@lists.infradead.org Link: http://lkml.kernel.org/r/D6CBEE2F420741indou.takao@jp.fujitsu.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'include/linux')
1 files changed, 4 insertions, 1 deletions
diff --git a/include/linux/smp.h b/include/linux/smp.h
index 7ad824d510a2..8cc38d3bab0c 100644
--- a/include/linux/smp.h
+++ b/include/linux/smp.h
@@ -85,12 +85,15 @@ int smp_call_function_any(const struct cpumask *mask,
* Generic and arch helpers
+void __init call_function_init(void);
void generic_smp_call_function_single_interrupt(void);
void generic_smp_call_function_interrupt(void);
void ipi_call_lock(void);
void ipi_call_unlock(void);
void ipi_call_lock_irq(void);
void ipi_call_unlock_irq(void);
+static inline void call_function_init(void) { }
@@ -134,7 +137,7 @@ static inline void smp_send_reschedule(int cpu) { }
#define smp_prepare_boot_cpu() do {} while (0)
#define smp_call_function_many(mask, func, info, wait) \
(up_smp_call_function(func, info))
-static inline void init_call_single_data(void) { }
+static inline void call_function_init(void) { }
static inline int
smp_call_function_any(const struct cpumask *mask, smp_call_func_t func,