linux.git, branch v3.15.4

Linux 3.15.4

2014-07-07T01:59:25+00:00

ALSA: hda - restore BCLK M/N values when resuming HSW/BDW display controller

2014-07-07T01:59:12+00:00

commit a07187c992be945ab561b370cbb49cfd72064c3c upstream.

For Intel Haswell/Broadwell display HD-A controller, the 24MHz HD-A link BCLK
is converted from Core Display Clock (CDCLK): BCLK = CDCLK * M / N
And there are two registers EM4 and EM5 to program M, N value respectively.
The EM4/EM5 values will be lost and when the display power well is disabled.

BIOS programs CDCLK selected by OEM and EM4/EM5, but BIOS has no idea about
display power well on/off at runtime. So the M/N can be wrong if non-default
CDCLK is used when the audio controller resumes, which results in an invalid
BCLK and abnormal audio playback rate. So this patch saves and restores valid
M/N values on controller suspend/resume.

And 'struct hda_intel' is defined to contain standard HD-A 'struct azx' and
Intel specific fields, as Takashi suggested.

Signed-off-by: Mengdong Lin 
Signed-off-by: Takashi Iwai 
Signed-off-by: Greg Kroah-Hartman

ALSA: hda - Adjust speaker HPF and add LED support for HP Spectre 13

2014-07-07T01:59:12+00:00

commit 8b3dfdaf0c25a584cb31d04d2574115cf2d422ab upstream.

HP Spectre 13 has the IDT 92HD95 codec, and BIOS seems to set the
default high-pass filter in some "safer" range, which results in the
very soft tone from the built-in speakers in contrast to Windows.
Also, the mute LED control is missing, since 92HD95 codec still has no
HP-specific fixups for GPIO setups.

This patch adds these missing features: the HPF is adjusted by the
vendor-specific verb, and the LED is set up from a DMI string (but
with the default polarity = 0 assumption due to the incomplete BIOS on
the given machine).

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=74841
Signed-off-by: Takashi Iwai 
Signed-off-by: Greg Kroah-Hartman

ALSA: hda - hdmi: call overridden init on resume

2014-07-07T01:59:12+00:00

commit a283368382c50345dff61525f493ea307f21ec9b upstream.

We need to call the proper init function in case it has been
overridden, as it might restore things that the generic routing
doesn't know anything about. E.g. AMD cards have special verbs
that need resetting.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=77901
Fixes: 5a61358433b1 ('ALSA: hda - hdmi: Add ATI/AMD multi-channel audio support')
Signed-off-by: Pierre Ossman 
Signed-off-by: Takashi Iwai 
Signed-off-by: Greg Kroah-Hartman

ALSA: usb-audio: Fix races at disconnection and PCM closing

2014-07-07T01:59:12+00:00

commit 92a586bdc06de6629dae1b357dac221253f55ff8 upstream.

When a USB-audio device is disconnected while PCM is still running, we
still see some race: the disconnect callback calls
snd_usb_endpoint_free() that calls release_urbs() and then kfree()
while a PCM stream would be closed at the same time and calls
stop_endpoints() that leads to wait_clear_urbs().  That is, the EP
object might be deallocated while a PCM stream is syncing with
wait_clear_urbs() with the same EP.

Basically calling multiple wait_clear_urbs() would work fine, also
calling wait_clear_urbs() and release_urbs() would work, too, as
wait_clear_urbs() just reads some fields in ep.  The problem is the
succeeding kfree() in snd_pcm_endpoint_free().

This patch moves out the EP deallocation into the later point, the
destructor callback.  At this stage, all PCMs must have been already
closed, so it's safe to free the objects.

Reported-by: Alan Stern 
Signed-off-by: Takashi Iwai 
Signed-off-by: Greg Kroah-Hartman

tracing: Fix syscall_*regfunc() vs copy_process() race

2014-07-07T01:59:12+00:00

commit 4af4206be2bd1933cae20c2b6fb2058dbc887f7c upstream.

syscall_regfunc() and syscall_unregfunc() should set/clear
TIF_SYSCALL_TRACEPOINT system-wide, but do_each_thread() can race
with copy_process() and miss the new child which was not added to
the process/thread lists yet.

Change copy_process() to update the child's TIF_SYSCALL_TRACEPOINT
under tasklist.

Link: http://lkml.kernel.org/p/20140413185854.GB20668@redhat.com

Fixes: a871bd33a6c0 "tracing: Add syscall tracepoints"
Acked-by: Frederic Weisbecker 
Acked-by: Paul E. McKenney 
Signed-off-by: Oleg Nesterov 
Signed-off-by: Steven Rostedt 
Signed-off-by: Greg Kroah-Hartman

tracing: Try again for saved cmdline if failed due to locking

2014-07-07T01:59:12+00:00

commit 379cfdac37923653c9d4242d10052378b7563005 upstream.

In order to prevent the saved cmdline cache from being filled when
tracing is not active, the comms are only recorded after a trace event
is recorded.

The problem is, a comm can fail to be recorded if the trace_cmdline_lock
is held. That lock is taken via a trylock to allow it to happen from
any context (including NMI). If the lock fails to be taken, the comm
is skipped. No big deal, as we will try again later.

But! Because of the code that was added to only record after an event,
we may not try again later as the recording is made as a oneshot per
event per CPU.

Only disable the recording of the comm if the comm is actually recorded.

Fixes: 7ffbd48d5cab "tracing: Cache comms only after an event occurred"
Signed-off-by: Steven Rostedt 
Signed-off-by: Greg Kroah-Hartman

Documentation/SubmittingPatches: describe the Fixes: tag

2014-07-07T01:59:12+00:00

commit 8401aa1f59975c03eeebd3ac6d264cbdfe9af5de upstream.

Update the SubmittingPatches process to include howto about the new
'Fixes:' tag to be used when a patch fixes an issue in a previous commit
(found by git-bisect for example).

Signed-off-by: Jacob Keller 
Tested-by: Aaron Brown 
Signed-off-by: Jeff Kirsher 
Cc: Randy Dunlap 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

lz4: add overrun checks to lz4_uncompress_unknownoutputsize()

2014-07-07T01:59:12+00:00

commit 4a3a99045177369700c60d074c0e525e8093b0fc upstream.

Jan points out that I forgot to make the needed fixes to the
lz4_uncompress_unknownoutputsize() function to mirror the changes done
in lz4_decompress() with regards to potential pointer overflows.

The only in-kernel user of this function is the zram code, which only
takes data from a valid compressed buffer that it made itself, so it's
not a big issue.  But due to external kernel modules using this
function, it's better to be safe here.

Reported-by: Jan Beulich 
Cc: "Don A. Bailey" 
Signed-off-by: Greg Kroah-Hartman

ptrace,x86: force IRET path after a ptrace_stop()

2014-07-07T01:59:12+00:00

commit b9cd18de4db3c9ffa7e17b0dc0ca99ed5aa4d43a upstream.

The 'sysret' fastpath does not correctly restore even all regular
registers, much less any segment registers or reflags values.  That is
very much part of why it's faster than 'iret'.

Normally that isn't a problem, because the normal ptrace() interface
catches the process using the signal handler infrastructure, which
always returns with an iret.

However, some paths can get caught using ptrace_event() instead of the
signal path, and for those we need to make sure that we aren't going to
return to user space using 'sysret'.  Otherwise the modifications that
may have been done to the register set by the tracer wouldn't
necessarily take effect.

Fix it by forcing IRET path by setting TIF_NOTIFY_RESUME from
arch_ptrace_stop_needed() which is invoked from ptrace_stop().

Signed-off-by: Tejun Heo 
Reported-by: Andy Lutomirski 
Acked-by: Oleg Nesterov 
Suggested-by: Linus Torvalds 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman