lkml.org 
[lkml]   [2016]   [Feb]   [10]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH 3.13.y-ckt 26/30] ALSA: dummy: Disable switching timer backend via sysfs
    Date
    3.13.11-ckt35 -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 915b4d7..f4d626c 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
    \
     
     \ /
      Last update: 2016-02-10 23:01    [W:2.683 / U:0.044 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site