ALSA: timer: Reject user params with too small ticks
authorTakashi Iwai <tiwai@suse.de>
Tue, 28 Feb 2017 13:49:07 +0000 (14:49 +0100)
committerTakashi Iwai <tiwai@suse.de>
Tue, 28 Feb 2017 14:06:01 +0000 (15:06 +0100)
commit71321eb3f2d0df4e6c327e0b936eec4458a12054
tree71fcacadc0b01afc9f386840d8089322631c2332
parent126cfa2f5e15ae2ca7f70be71b07e6cd8d2b44d1
ALSA: timer: Reject user params with too small ticks

When a user sets a too small ticks with a fine-grained timer like
hrtimer, the kernel tries to fire up the timer irq too frequently.
This may lead to the condensed locks, eventually the kernel spinlock
lockup with warnings.

For avoiding such a situation, we define a lower limit of the
resolution, namely 1ms.  When the user passes a too small tick value
that results in less than that, the kernel returns -EINVAL now.

Reported-by: Dmitry Vyukov <dvyukov@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
sound/core/timer.c