summaryrefslogtreecommitdiff
path: root/sound/drivers
diff options
context:
space:
mode:
authorTakashi Iwai <tiwai@suse.de>2016-01-28 09:54:16 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2016-02-17 23:30:58 +0300
commitd0cc6515b1238f90c61b713160e94ff768b43325 (patch)
tree6757a4492417e0c8678d112b46121d2a442ca6b2 /sound/drivers
parent1963ffef4a1a92a07773bf8a30ce1224dd861bd5 (diff)
downloadlinux-d0cc6515b1238f90c61b713160e94ff768b43325.tar.xz
ALSA: dummy: Disable switching timer backend via sysfs
commit 7ee96216c31aabe1eb42fb91ff50dae9fcd014b2 upstream. ALSA dummy driver can switch the timer backend between system timer and hrtimer via its hrtimer module option. This can be also switched dynamically via sysfs, but it may lead to a memory corruption when switching is done while a PCM stream is running; the stream instance for the newly switched timer method tries to access the memory that was allocated by another timer method although the sizes differ. As the simplest fix, this patch just disables the switch via sysfs by dropping the writable bit. BugLink: http://lkml.kernel.org/r/CACT4Y+ZGEeEBntHW5WHn2GoeE0G_kRrCmUh6=dWyy-wfzvuJLg@mail.gmail.com Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'sound/drivers')
-rw-r--r--sound/drivers/dummy.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/sound/drivers/dummy.c b/sound/drivers/dummy.c
index 016e451ed506..df8e757deb58 100644
--- a/sound/drivers/dummy.c
+++ b/sound/drivers/dummy.c
@@ -87,7 +87,7 @@ MODULE_PARM_DESC(pcm_substreams, "PCM substreams # (1-128) for dummy driver.");
module_param(fake_buffer, bool, 0444);
MODULE_PARM_DESC(fake_buffer, "Fake buffer allocations.");
#ifdef CONFIG_HIGH_RES_TIMERS
-module_param(hrtimer, bool, 0644);
+module_param(hrtimer, bool, 0444);
MODULE_PARM_DESC(hrtimer, "Use hrtimer as the timer source.");
#endif