linux/drivers/char/hw_random
Prarit Bhargava ee527cd3a2 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>
2007-05-08 11:15:00 -07:00
..
amd-rng.c [PATCH] Fix HWRNG built-in initcalls priority 2007-01-11 18:18:21 -08:00
core.c [PATCH] severing fs.h, radix-tree.h -> sched.h 2006-12-04 02:00:24 -05:00
geode-rng.c [PATCH] Fix HWRNG built-in initcalls priority 2007-01-11 18:18:21 -08:00
intel-rng.c Use stop_machine_run in the Intel RNG driver 2007-05-08 11:15:00 -07:00
ixp4xx-rng.c [PATCH] Fix HWRNG built-in initcalls priority 2007-01-11 18:18:21 -08:00
Kconfig [PATCH] allow hwrandom core to be a module 2006-12-07 08:39:39 -08:00
Makefile [PATCH] allow hwrandom core to be a module 2006-12-07 08:39:39 -08:00
omap-rng.c fix file specification in comments 2006-10-03 23:01:26 +02:00
via-rng.c PCI: Cleanup the includes of <linux/pci.h> 2007-05-02 19:02:35 -07:00