Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit e1d9694c authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'core-fixes-for-linus' of... 

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
parents 39c12be8 b3a084b9

include/linux/rcupdate.h

+1 −1
Original line number Diff line number Diff line
@@ -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

kernel/smp.c

+14 −3
Original line number Diff line number Diff line
@@ -365,9 +365,10 @@ int smp_call_function_any(const struct cpumask *mask, 
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
@@ -387,8 +390,16 @@ 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);



	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();

}



/**

 * smp_call_function_many(): Run a function on a set of other CPUs.