Skip to main content

Browse the archive

https://github.com/torvalds/linux
13 June 2022, 11:31:42 UTC
Revision c6482dde1c2811afba289b2344268f850595f350 authored by Arjan van de Ven on 04 July 2006, 10:07:22 UTC, committed by Linus Torvalds on 04 July 2006, 17:24:57 UTC 
[PATCH] fix AB-BA deadlock inversion at cs46xx_dsp_remove_scb
 
There is a code sequence where the locking is substream->self_group.lock
-> ins->scbs[index].lock

substream->self_group.lock is interrupt safe, and taken from irq context
as well (trace is snipped for brevity)

so what can happen is

   cpu 0                   	cpu 1
   user context			user context

				take ins->scbs[index].lock without disabling interrupts

   get substream->self_group.lock (irqsafe)
   try to get ins->scbs[index].lock (spins)

				interrupt happens
				try to get substream->self_group.lock (spins)

which is an obvious AB-BA deadlock

fix is to just take the lock with _irqsafe

Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Cc: Jaroslav Kysela <perex@suse.cz>
Acked-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
1 parent a46f948
History
Tip revision: c6482dde1c2811afba289b2344268f850595f350 authored by Arjan van de Ven on 04 July 2006, 10:07:22 UTC
[PATCH] fix AB-BA deadlock inversion at cs46xx_dsp_remove_scb
Tip revision: c6482dd
File Mode Size
Documentation
arch
block
crypto
drivers
fs
include
init
ipc
kernel
lib
mm
net
scripts
security
sound
usr
.gitignore -rw-r--r-- 462 bytes
COPYING -rw-r--r-- 18.3 KB
CREDITS -rw-r--r-- 87.5 KB
Kbuild -rw-r--r-- 1.2 KB
MAINTAINERS -rw-r--r-- 69.5 KB
Makefile -rw-r--r-- 45.4 KB
README -rw-r--r-- 16.2 KB
REPORTING-BUGS -rw-r--r-- 3.0 KB

README

back to top