Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1327263 > unrolled thread

[PATCH 4.2.y-ckt 57/64] ALSA: dummy: Disable switching timer backend via sysfs

Back to article view | Back to linux.kernel

This discussion starts older than the indexed window; earlier articles aren't shown. The article labeled Started by below is the oldest one visible, not the original post.

Contents

  [PATCH 4.2.y-ckt 57/64] ALSA: dummy: Disable switching timer backend via sysfs Kamal Mostafa <kamal@canonical.com> - 2016-02-04 23:50 +0100

#1327263 — [PATCH 4.2.y-ckt 57/64] ALSA: dummy: Disable switching timer backend via sysfs

4.2.8-ckt4 -stable review patch.  If anyone has any objections, please let me know.

---8<------------------------------------------------------------

From: Takashi Iwai <tiwai@suse.de>

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: Kamal Mostafa <kamal@canonical.com>
---
 sound/drivers/dummy.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/sound/drivers/dummy.c b/sound/drivers/dummy.c
index 016e451..df8e757 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
 
-- 
1.9.1

[toc] | [standalone]

Back to top | Article view | linux.kernel

csiph-web