Hi all,
This patch renames init_call_single_data() to call_function_init() and
calls it in start_kernel() so that call_single_queue can be initialized
before enabling interrupt.
There is a problem that kdump(2nd kernel) sometimes hangs up due to
pending IPI from 1st kernel. Kernel panic occurs because IPI comes
before call_single_queue is initialized. The details are as follows.
(1) 2nd kernel boot 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().
v2:
- Rename init_call_single_data() to call_function_init() and calls it in
start_kernel()
- Change insert position in start_kernel().
- Adjust for CONFIG_SMP/CONFIG_USE_GENERIC_SMP_HELPERS options
- Rebased to Linus's latest tree
v1:
https://lkml.org/lkml/2011/3/25/317
- Divide init_call_single_data() into two functions,
o init_call_single_data: initialize call_single_queue
o init_hotplug_cfd: initialize hotplug_cfd_notifier
And call init_call_single_data before local_irq_enable() in
start_kernel().
v0:
https://lkml.org/lkml/2011/3/23/417
- In generic_smp_call_function_single_interrupt(), check if
call_single_queue was initialized or not, and just return if not
initialized.
Signed-off-by: Takao Indoh <indou.takao at jp.fujitsu.com>
---
include/linux/smp.h | 5 ++++-
init/main.c | 1 +
kernel/smp.c | 5 +----
3 files changed, 6 insertions(+), 5 deletions(-)
diff --git a/include/linux/smp.h b/include/linux/smp.h
index 74243c8..4fb3eac 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
/*
@@ -144,7 +147,7 @@ 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 4a9479e..12821d1 100644
--- a/init/main.c
+++ b/init/main.c
@@ -539,6 +539,7 @@ 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 73a1951..fb67dfa 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
