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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
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>
-rw-r--r--include/linux/smp.h5
-rw-r--r--init/main.c1
-rw-r--r--kernel/smp.c5
3 files changed, 6 insertions, 5 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
*/
#ifdef CONFIG_USE_GENERIC_SMP_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);
+#else
+static inline void call_function_init(void) { }
#endif
/*
@@ -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,
diff --git a/init/main.c b/init/main.c
index cafba67c13bf..d7211faed2ad 100644
--- a/init/main.c
+++ b/init/main.c
@@ -542,6 +542,7 @@ asmlinkage void __init start_kernel(void)
timekeeping_init();
time_init();
profile_init();
+ call_function_init();
if (!irqs_disabled())
printk(KERN_CRIT "start_kernel(): bug: interrupts were "
"enabled early\n");
diff --git a/kernel/smp.c b/kernel/smp.c
index 73a195193558..fb67dfa8394e 100644
--- a/kernel/smp.c
+++ b/kernel/smp.c
@@ -74,7 +74,7 @@ static struct notifier_block __cpuinitdata hotplug_cfd_notifier = {
.notifier_call = hotplug_cfd,
};
-static int __cpuinit init_call_single_data(void)
+void __init call_function_init(void)
{
void *cpu = (void *)(long)smp_processor_id();
int i;
@@ -88,10 +88,7 @@ static int __cpuinit init_call_single_data(void)
hotplug_cfd(&hotplug_cfd_notifier, CPU_UP_PREPARE, cpu);
register_cpu_notifier(&hotplug_cfd_notifier);
-
- return 0;
}
-early_initcall(init_call_single_data);
/*
* csd_lock/csd_unlock used to serialize access to per-cpu csd resources