linux-next

mirror of https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git synced 2025-01-11 00:08:50 +00:00

History

Seiji Aguchi e59310adf5 efi_pstore: Avoid deadlock in non-blocking paths

[Issue]

There is a scenario which efi_pstore may hang up:

 - cpuA grabs efivars->lock
 - cpuB panics and calls smp_send_stop
 - smp_send_stop sends IRQ to cpuA
 - after 1 second, cpuB gives up on cpuA and sends an NMI instead
 - cpuA is now in an NMI handler while still holding efivars->lock
 - cpuB is deadlocked

This case may happen if a firmware has a bug and
cpuA is stuck talking with it.

[Solution]

This patch changes a spin_lock to a spin_trylock in non-blocking paths.
and if the spin_lock has already taken by another cpu,
it returns without accessing to a firmware to avoid the deadlock.

Signed-off-by: Seiji Aguchi <seiji.aguchi@hds.com>
Acked-by: Don Zickus <dzickus@redhat.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>

2013-01-11 10:21:56 -08:00

google

firmware: google: fix gsmi.c build warning

2011-12-09 16:23:49 -08:00

dcdbas.c

dcdbas: force SMI to happen when expected

2011-03-02 13:42:10 +01:00

dcdbas.h

dcdbas: export functionality for use in other drivers

2009-01-08 08:31:12 -08:00

dell_rbu.c

sysfs: add struct file* to bin_attr callbacks