diff options
| author | Prarit Bhargava <prarit@redhat.com> | 2007-05-08 00:25:08 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-05-08 11:15:00 -0700 |
| commit | ee527cd3a20c2aeaac17d939e5d011f7a76d69f5 (patch) | |
| tree | 113e8dd439c5a3656be07058f055e6340ad41623 /kernel/stop_machine.c | |
| parent | 616883df78bd4b3fcdb6ddc39bd3d4cb902bfa32 (diff) | |
Use stop_machine_run in the Intel RNG driver
Replace call_smp_function with stop_machine_run in the Intel RNG driver.
CPU A has done read_lock(&lock)
CPU B has done write_lock_irq(&lock) and is waiting for A to release the lock.
A third CPU calls call_smp_function and issues the IPI. CPU A takes CPU
C's IPI. CPU B is waiting with interrupts disabled and does not see the
IPI. CPU C is stuck waiting for CPU B to respond to the IPI.
Deadlock.
The solution is to use stop_machine_run instead of call_smp_function
(call_smp_function should not be called in situations where the CPUs may be
suspended).
[haruo.tomita@toshiba.co.jp: fix a typo in mod_init()]
[haruo.tomita@toshiba.co.jp: fix memory leak]
Signed-off-by: Prarit Bhargava <prarit@redhat.com>
Cc: Jan Beulich <jbeulich@novell.com>
Cc: "Tomita, Haruo" <haruo.tomita@toshiba.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel/stop_machine.c')
| -rw-r--r-- | kernel/stop_machine.c | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/kernel/stop_machine.c b/kernel/stop_machine.c index 12458040e66..daabb74ee0b 100644 --- a/kernel/stop_machine.c +++ b/kernel/stop_machine.c @@ -1,11 +1,12 @@ /* Copyright 2005 Rusty Russell rusty@rustcorp.com.au IBM Corporation. * GPL v2 and any later version. */ -#include <linux/stop_machine.h> -#include <linux/kthread.h> -#include <linux/sched.h> #include <linux/cpu.h> #include <linux/err.h> +#include <linux/kthread.h> +#include <linux/module.h> +#include <linux/sched.h> +#include <linux/stop_machine.h> #include <linux/syscalls.h> #include <asm/atomic.h> #include <asm/semaphore.h> @@ -208,3 +209,4 @@ int stop_machine_run(int (*fn)(void *), void *data, unsigned int cpu) return ret; } +EXPORT_SYMBOL_GPL(stop_machine_run); |