Merge branch 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: rcu: rcu_read_lock_bh_held(): disabling irqs also disables bh generic-ipi: Fix deadlock in __smp_call_function_single
This commit is contained in:
commit
e1d9694cae
2 changed files with 15 additions and 4 deletions
|
@ -454,7 +454,7 @@ static inline notrace void rcu_read_unlock_sched_notrace(void)
|
|||
* Makes rcu_dereference_check() do the dirty work.
|
||||
*/
|
||||
#define rcu_dereference_bh(p) \
|
||||
rcu_dereference_check(p, rcu_read_lock_bh_held())
|
||||
rcu_dereference_check(p, rcu_read_lock_bh_held() || irqs_disabled())
|
||||
|
||||
/**
|
||||
* rcu_dereference_sched - fetch RCU-protected pointer, checking for RCU-sched
|
||||
|
|
17
kernel/smp.c
17
kernel/smp.c
|
@ -365,9 +365,10 @@ call:
|
|||
EXPORT_SYMBOL_GPL(smp_call_function_any);
|
||||
|
||||
/**
|
||||
* __smp_call_function_single(): Run a function on another CPU
|
||||
* __smp_call_function_single(): Run a function on a specific CPU
|
||||
* @cpu: The CPU to run on.
|
||||
* @data: Pre-allocated and setup data structure
|
||||
* @wait: If true, wait until function has completed on specified CPU.
|
||||
*
|
||||
* Like smp_call_function_single(), but allow caller to pass in a
|
||||
* pre-allocated data structure. Useful for embedding @data inside
|
||||
|
@ -376,8 +377,10 @@ EXPORT_SYMBOL_GPL(smp_call_function_any);
|
|||
void __smp_call_function_single(int cpu, struct call_single_data *data,
|
||||
int wait)
|
||||
{
|
||||
csd_lock(data);
|
||||
unsigned int this_cpu;
|
||||
unsigned long flags;
|
||||
|
||||
this_cpu = get_cpu();
|
||||
/*
|
||||
* Can deadlock when called with interrupts disabled.
|
||||
* We allow cpu's that are not yet online though, as no one else can
|
||||
|
@ -387,7 +390,15 @@ void __smp_call_function_single(int cpu, struct call_single_data *data,
|
|||
WARN_ON_ONCE(cpu_online(smp_processor_id()) && wait && irqs_disabled()
|
||||
&& !oops_in_progress);
|
||||
|
||||
generic_exec_single(cpu, data, wait);
|
||||
if (cpu == this_cpu) {
|
||||
local_irq_save(flags);
|
||||
data->func(data->info);
|
||||
local_irq_restore(flags);
|
||||
} else {
|
||||
csd_lock(data);
|
||||
generic_exec_single(cpu, data, wait);
|
||||
}
|
||||
put_cpu();
|
||||
}
|
||||
|
||||
/**
|
||||
|
|
Loading…
Reference in a new issue