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Commit Graph

19522 Commits

Author SHA1 Message Date
Paul E. McKenney
917963d0b3 rcutorture: Check from beginning to end of grace period
Currently, rcutorture's Reader Batch checks measure from the end of
the previous grace period to the end of the current one.  This commit
tightens up these checks by measuring from the start and end of the same
grace period.  This involves adding rcu_batches_started() and friends
corresponding to the existing rcu_batches_completed() and friends.

We leave SRCU alone for the moment, as it does not yet have a way of
tracking both ends of its grace periods.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2015-01-10 19:08:02 -08:00
Paul E. McKenney
f9103c3902 rcu: Remove redundant rcu_batches_completed() declaration
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2015-01-10 19:08:01 -08:00
Paul E. McKenney
1e32eaee4c rcutorture: Drop rcu_torture_completed() and friends
Now that the return type of rcu_batches_completed() and friends matches
that of the rcu_torture_ops structure's ->completed field, the wrapper
functions can be deleted.  This commit carries out that deletion, while
also wiring "sched"'s ->completed field to rcu_batches_completed_sched().

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2015-01-10 19:08:00 -08:00
Paul E. McKenney
6b80da42c0 rcutorture: Use unsigned for Reader Batch computations
The counter returned by the various ->completed functions is subject to
overflow, which means that subtracting two such counters might result
in overflow, which invokes undefined behavior in the C standard.  This
commit therefore changes these functions and variables to unsigned to
avoid this undefined behavior.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2015-01-10 19:07:58 -08:00
Paul E. McKenney
9733e4f0a9 rcu: Make _batches_completed() functions return unsigned long
Long ago, the various ->completed fields were of type long, but now are
unsigned long due to signed-integer-overflow concerns.  However, the
various _batches_completed() functions remained of type long, even though
their only purpose in life is to return the corresponding ->completed
field.  This patch cleans this up by changing these functions' return
types to unsigned long.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2015-01-10 19:07:56 -08:00
Paul E. McKenney
734d168013 rcu: Make rcu_nmi_enter() handle nesting
The x86 architecture has multiple types of NMI-like interrupts: real
NMIs, machine checks, and, for some values of NMI-like, debugging
and breakpoint interrupts.  These interrupts can nest inside each
other.  Andy Lutomirski is adding RCU support to these interrupts,
so rcu_nmi_enter() and rcu_nmi_exit() must now correctly handle nesting.

This commit therefore introduces nesting, using a clever NMI-coordination
algorithm suggested by Andy.  The trick is to atomically increment
->dynticks (if needed) before manipulating ->dynticks_nmi_nesting on entry
(and, accordingly, after on exit).  In addition, ->dynticks_nmi_nesting
is incremented by one if ->dynticks was incremented and by two otherwise.
This means that when rcu_nmi_exit() sees ->dynticks_nmi_nesting equal
to one, it knows that ->dynticks must be atomically incremented.

This NMI-coordination algorithms has been validated by the following
Promela model:

------------------------------------------------------------------------

/*
 * Promela model for Andy Lutomirski's suggested change to rcu_nmi_enter()
 * that allows nesting.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, you can access it online at
 * http://www.gnu.org/licenses/gpl-2.0.html.
 *
 * Copyright IBM Corporation, 2014
 *
 * Author: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
 */

byte dynticks_nmi_nesting = 0;
byte dynticks = 0;

/*
 * Promela verision of rcu_nmi_enter().
 */
inline rcu_nmi_enter()
{
	byte incby;
	byte tmp;

	incby = BUSY_INCBY;
	assert(dynticks_nmi_nesting >= 0);
	if
	:: (dynticks & 1) == 0 ->
		atomic {
			dynticks = dynticks + 1;
		}
		assert((dynticks & 1) == 1);
		incby = 1;
	:: else ->
		skip;
	fi;
	tmp = dynticks_nmi_nesting;
	tmp = tmp + incby;
	dynticks_nmi_nesting = tmp;
	assert(dynticks_nmi_nesting >= 1);
}

/*
 * Promela verision of rcu_nmi_exit().
 */
inline rcu_nmi_exit()
{
	byte tmp;

	assert(dynticks_nmi_nesting > 0);
	assert((dynticks & 1) != 0);
	if
	:: dynticks_nmi_nesting != 1 ->
		tmp = dynticks_nmi_nesting;
		tmp = tmp - BUSY_INCBY;
		dynticks_nmi_nesting = tmp;
	:: else ->
		dynticks_nmi_nesting = 0;
		atomic {
			dynticks = dynticks + 1;
		}
		assert((dynticks & 1) == 0);
	fi;
}

/*
 * Base-level NMI runs non-atomically.  Crudely emulates process-level
 * dynticks-idle entry/exit.
 */
proctype base_NMI()
{
	byte busy;

	busy = 0;
	do
	::	/* Emulate base-level dynticks and not. */
		if
		:: 1 ->	atomic {
				dynticks = dynticks + 1;
			}
			busy = 1;
		:: 1 ->	skip;
		fi;

		/* Verify that we only sometimes have base-level dynticks. */
		if
		:: busy == 0 -> skip;
		:: busy == 1 -> skip;
		fi;

		/* Model RCU's NMI entry and exit actions. */
		rcu_nmi_enter();
		assert((dynticks & 1) == 1);
		rcu_nmi_exit();

		/* Emulated re-entering base-level dynticks and not. */
		if
		:: !busy -> skip;
		:: busy ->
			atomic {
				dynticks = dynticks + 1;
			}
			busy = 0;
		fi;

		/* We had better now be in dyntick-idle mode. */
		assert((dynticks & 1) == 0);
	od;
}

/*
 * Nested NMI runs atomically to emulate interrupting base_level().
 */
proctype nested_NMI()
{
	do
	::	/*
		 * Use an atomic section to model a nested NMI.  This is
		 * guaranteed to interleave into base_NMI() between a pair
		 * of base_NMI() statements, just as a nested NMI would.
		 */
		atomic {
			/* Verify that we only sometimes are in dynticks. */
			if
			:: (dynticks & 1) == 0 -> skip;
			:: (dynticks & 1) == 1 -> skip;
			fi;

			/* Model RCU's NMI entry and exit actions. */
			rcu_nmi_enter();
			assert((dynticks & 1) == 1);
			rcu_nmi_exit();
		}
	od;
}

init {
	run base_NMI();
	run nested_NMI();
}

------------------------------------------------------------------------

The following script can be used to run this model if placed in
rcu_nmi.spin:

------------------------------------------------------------------------

if ! spin -a rcu_nmi.spin
then
	echo Spin errors!!!
	exit 1
fi
if ! cc -DSAFETY -o pan pan.c
then
	echo Compilation errors!!!
	exit 1
fi
./pan -m100000

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Lai Jiangshan <laijs@cn.fujitsu.com>
2014-12-30 17:40:16 -08:00
Linus Torvalds
5d6a546886 CONFIG_PM_RUNTIME elimination for 3.19-rc1
This removes the last few uses of CONFIG_PM_RUNTIME introduced
 recently and makes that config option finally go away.
 
 CONFIG_PM will be available directly from the menu now and
 also it will be selected automatically if CONFIG_SUSPEND or
 CONFIG_HIBERNATION is set.
 
 /
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Merge tag 'pm-config-3.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull CONFIG_PM_RUNTIME elimination from Rafael Wysocki:
 "This removes the last few uses of CONFIG_PM_RUNTIME introduced
  recently and makes that config option finally go away.

  CONFIG_PM will be available directly from the menu now and also it
  will be selected automatically if CONFIG_SUSPEND or CONFIG_HIBERNATION
  is set"

* tag 'pm-config-3.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  PM: Eliminate CONFIG_PM_RUNTIME
  tty: 8250_omap: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  sound: sst-haswell-pcm: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  spi: Replace CONFIG_PM_RUNTIME with CONFIG_PM
2014-12-20 13:37:44 -08:00
Rafael J. Wysocki
464ed18ebd PM: Eliminate CONFIG_PM_RUNTIME
Having switched over all of the users of CONFIG_PM_RUNTIME to use
CONFIG_PM directly, turn the latter into a user-selectable option
and drop the former entirely from the tree.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Kevin Hilman <khilman@linaro.org>
2014-12-19 22:55:06 +01:00
Linus Torvalds
4bb9374e0b Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull NOHZ update from Thomas Gleixner:
 "Remove the call into the nohz idle code from the fake 'idle' thread in
  the powerclamp driver along with the export of those functions which
  was smuggeled in via the thermal tree.  People have tried to hack
  around it in the nohz core code, but it just violates all rightful
  assumptions of that code about the only valid calling context (i.e.
  the proper idle task).

  The powerclamp trainwreck will still work, it just wont get the
  benefit of long idle sleeps"

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  tick/powerclamp: Remove tick_nohz_idle abuse
2014-12-19 13:29:20 -08:00
Linus Torvalds
ac88ee3b6c Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull irq core fix from Thomas Gleixner:
 "A single fix plugging a long standing race between proc/stat and
  proc/interrupts access and freeing of interrupt descriptors"

* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  genirq: Prevent proc race against freeing of irq descriptors
2014-12-19 13:26:08 -08:00
Linus Torvalds
88a57667f2 Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf fixes and cleanups from Ingo Molnar:
 "A kernel fix plus mostly tooling fixes, but also some tooling
  restructuring and cleanups"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (39 commits)
  perf: Fix building warning on ARM 32
  perf symbols: Fix use after free in filename__read_build_id
  perf evlist: Use roundup_pow_of_two
  tools: Adopt roundup_pow_of_two
  perf tools: Make the mmap length autotuning more robust
  tools: Adopt rounddown_pow_of_two and deps
  tools: Adopt fls_long and deps
  tools: Move bitops.h from tools/perf/util to tools/
  tools: Introduce asm-generic/bitops.h
  tools lib: Move asm-generic/bitops/find.h code to tools/include and tools/lib
  tools: Whitespace prep patches for moving bitops.h
  tools: Move code originally from asm-generic/atomic.h into tools/include/asm-generic/
  tools: Move code originally from linux/log2.h to tools/include/linux/
  tools: Move __ffs implementation to tools/include/asm-generic/bitops/__ffs.h
  perf evlist: Do not use hard coded value for a mmap_pages default
  perf trace: Let the perf_evlist__mmap autosize the number of pages to use
  perf evlist: Improve the strerror_mmap method
  perf evlist: Clarify sterror_mmap variable names
  perf evlist: Fixup brown paper bag on "hint" for --mmap-pages cmdline arg
  perf trace: Provide a better explanation when mmap fails
  ...
2014-12-19 13:15:24 -08:00
Thomas Gleixner
a5fd9733a3 tick/powerclamp: Remove tick_nohz_idle abuse
commit 4dbd27711c "tick: export nohz tick idle symbols for module
use" was merged via the thermal tree without an explicit ack from the
relevant maintainers.

The exports are abused by the intel powerclamp driver which implements
a fake idle state from a sched FIFO task. This causes all kinds of
wreckage in the NOHZ core code which rightfully assumes that
tick_nohz_idle_enter/exit() are only called from the idle task itself.

Recent changes in the NOHZ core lead to a failure of the powerclamp
driver and now people try to hack completely broken and backwards
workarounds into the NOHZ core code. This is completely unacceptable
and just papers over the real problem. There are way more subtle
issues lurking around the corner.

The real solution is to fix the powerclamp driver by rewriting it with
a sane concept, but that's beyond the scope of this.

So the only solution for now is to remove the calls into the core NOHZ
code from the powerclamp trainwreck along with the exports. 

Fixes: d6d71ee4a1 "PM: Introduce Intel PowerClamp Driver"
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Cc: Frederic Weisbecker <frederic@kernel.org>
Cc: Pan Jacob jun <jacob.jun.pan@intel.com>
Cc: LKP <lkp@01.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Zhang Rui <rui.zhang@intel.com>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1412181110110.17382@nanos
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2014-12-19 14:05:52 +01:00
Linus Torvalds
d790be3863 The exciting thing here is the getting rid of stop_machine on module
removal.  This is possible by using a simple atomic_t for the counter,
 rather than our fancy per-cpu counter: it turns out that no one is doing
 a module increment per net packet, so the slowdown should be in the noise.
 
 Also, script fixed for new git version.
 
 Cheers,
 Rusty.
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Merge tag 'modules-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux

Pull module updates from Rusty Russell:
 "The exciting thing here is the getting rid of stop_machine on module
  removal.  This is possible by using a simple atomic_t for the counter,
  rather than our fancy per-cpu counter: it turns out that no one is
  doing a module increment per net packet, so the slowdown should be in
  the noise"

* tag 'modules-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux:
  param: do not set store func without write perm
  params: cleanup sysfs allocation
  kernel:module Fix coding style errors and warnings.
  module: Remove stop_machine from module unloading
  module: Replace module_ref with atomic_t refcnt
  lib/bug: Use RCU list ops for module_bug_list
  module: Unlink module with RCU synchronizing instead of stop_machine
  module: Wait for RCU synchronizing before releasing a module
2014-12-18 20:55:41 -08:00
Linus Torvalds
c0f486fde3 More ACPI and power management updates for 3.19-rc1
- Fix a regression in leds-gpio introduced by a recent commit that
    inadvertently changed the name of one of the properties used by
    the driver (Fabio Estevam).
 
  - Fix a regression in the ACPI backlight driver introduced by a
    recent fix that missed one special case that had to be taken
    into account (Aaron Lu).
 
  - Drop the level of some new kernel messages from the ACPI core
    introduced by a recent commit to KERN_DEBUG which they should
    have used from the start and drop some other unuseful KERN_ERR
    messages printed by ACPI (Rafael J Wysocki).
 
  - Revert an incorrect commit modifying the cpupower tool
    (Prarit Bhargava).
 
  - Fix two regressions introduced by recent commits in the OPP
    library and clean up some existing minor issues in that code
    (Viresh Kumar).
 
  - Continue to replace CONFIG_PM_RUNTIME with CONFIG_PM throughout
    the tree (or drop it where that can be done) in order to make
    it possible to eliminate CONFIG_PM_RUNTIME (Rafael J Wysocki,
    Ulf Hansson, Ludovic Desroches).  There will be one more
    "CONFIG_PM_RUNTIME removal" batch after this one, because some
    new uses of it have been introduced during the current merge
    window, but that should be sufficient to finally get rid of it.
 
  - Make the ACPI EC driver more robust against race conditions
    related to GPE handler installation failures (Lv Zheng).
 
  - Prevent the ACPI device PM core code from attempting to
    disable GPEs that it has not enabled which confuses ACPICA
    and makes it report errors unnecessarily (Rafael J Wysocki).
 
  - Add a "force" command line switch to the intel_pstate driver
    to make it possible to override the blacklisting of some
    systems in that driver if needed (Ethan Zhao).
 
  - Improve intel_pstate code documentation and add a MAINTAINERS
    entry for it (Kristen Carlson Accardi).
 
  - Make the ACPI fan driver create cooling device interfaces
    witn names that reflect the IDs of the ACPI device objects
    they are associated with, except for "generic" ACPI fans
    (PNP ID "PNP0C0B").  That's necessary for user space thermal
    management tools to be able to connect the fans with the
    parts of the system they are supposed to be cooling properly.
    From Srinivas Pandruvada.
 
 /
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Merge tag 'pm+acpi-3.19-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull more ACPI and power management updates from Rafael Wysocki:
 "These are regression fixes (leds-gpio, ACPI backlight driver,
  operating performance points library, ACPI device enumeration
  messages, cpupower tool), other bug fixes (ACPI EC driver, ACPI device
  PM), some cleanups in the operating performance points (OPP)
  framework, continuation of CONFIG_PM_RUNTIME elimination, a couple of
  minor intel_pstate driver changes, a new MAINTAINERS entry for it and
  an ACPI fan driver change needed for better support of thermal
  management in user space.

  Specifics:

   - Fix a regression in leds-gpio introduced by a recent commit that
     inadvertently changed the name of one of the properties used by the
     driver (Fabio Estevam).

   - Fix a regression in the ACPI backlight driver introduced by a
     recent fix that missed one special case that had to be taken into
     account (Aaron Lu).

   - Drop the level of some new kernel messages from the ACPI core
     introduced by a recent commit to KERN_DEBUG which they should have
     used from the start and drop some other unuseful KERN_ERR messages
     printed by ACPI (Rafael J Wysocki).

   - Revert an incorrect commit modifying the cpupower tool (Prarit
     Bhargava).

   - Fix two regressions introduced by recent commits in the OPP library
     and clean up some existing minor issues in that code (Viresh
     Kumar).

   - Continue to replace CONFIG_PM_RUNTIME with CONFIG_PM throughout the
     tree (or drop it where that can be done) in order to make it
     possible to eliminate CONFIG_PM_RUNTIME (Rafael J Wysocki, Ulf
     Hansson, Ludovic Desroches).

     There will be one more "CONFIG_PM_RUNTIME removal" batch after this
     one, because some new uses of it have been introduced during the
     current merge window, but that should be sufficient to finally get
     rid of it.

   - Make the ACPI EC driver more robust against race conditions related
     to GPE handler installation failures (Lv Zheng).

   - Prevent the ACPI device PM core code from attempting to disable
     GPEs that it has not enabled which confuses ACPICA and makes it
     report errors unnecessarily (Rafael J Wysocki).

   - Add a "force" command line switch to the intel_pstate driver to
     make it possible to override the blacklisting of some systems in
     that driver if needed (Ethan Zhao).

   - Improve intel_pstate code documentation and add a MAINTAINERS entry
     for it (Kristen Carlson Accardi).

   - Make the ACPI fan driver create cooling device interfaces witn
     names that reflect the IDs of the ACPI device objects they are
     associated with, except for "generic" ACPI fans (PNP ID "PNP0C0B").

     That's necessary for user space thermal management tools to be able
     to connect the fans with the parts of the system they are supposed
     to be cooling properly.  From Srinivas Pandruvada"

* tag 'pm+acpi-3.19-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (32 commits)
  MAINTAINERS: add entry for intel_pstate
  ACPI / video: update the skip case for acpi_video_device_in_dod()
  power / PM: Eliminate CONFIG_PM_RUNTIME
  NFC / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  SCSI / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  ACPI / EC: Fix unexpected ec_remove_handlers() invocations
  Revert "tools: cpupower: fix return checks for sysfs_get_idlestate_count()"
  tracing / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  x86 / PM: Replace CONFIG_PM_RUNTIME in io_apic.c
  PM: Remove the SET_PM_RUNTIME_PM_OPS() macro
  mmc: atmel-mci: use SET_RUNTIME_PM_OPS() macro
  PM / Kconfig: Replace PM_RUNTIME with PM in dependencies
  ARM / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  sound / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  phy / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  video / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  tty / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  spi: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  ACPI / PM: Do not disable wakeup GPEs that have not been enabled
  ACPI / utils: Drop error messages from acpi_evaluate_reference()
  ...
2014-12-18 20:28:33 -08:00
Kees Cook
b0a65b0ccc param: do not set store func without write perm
When a module_param is defined without DAC write permissions, it can
still be changed at runtime and updated. Drivers using a 0444 permission
may be surprised that these values can still be changed.

For drivers that want to allow updates, any S_IW* flag will set the
"store" function as before. Drivers without S_IW* flags will have the
"store" function unset, unforcing a read-only value. Drivers that wish
neither "store" nor "get" can continue to use "0" for perms to stay out
of sysfs entirely.

Old behavior:
  # cd /sys/module/snd/parameters
  # ls -l
  total 0
  -r--r--r-- 1 root root 4096 Dec 11 13:55 cards_limit
  -r--r--r-- 1 root root 4096 Dec 11 13:55 major
  -r--r--r-- 1 root root 4096 Dec 11 13:55 slots
  # cat major
  116
  # echo -1 > major
  -bash: major: Permission denied
  # chmod u+w major
  # echo -1 > major
  # cat major
  -1

New behavior:
  ...
  # chmod u+w major
  # echo -1 > major
  -bash: echo: write error: Input/output error

Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2014-12-18 12:38:51 +10:30
Linus Torvalds
87c31b39ab Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
Pull user namespace related fixes from Eric Biederman:
 "As these are bug fixes almost all of thes changes are marked for
  backporting to stable.

  The first change (implicitly adding MNT_NODEV on remount) addresses a
  regression that was created when security issues with unprivileged
  remount were closed.  I go on to update the remount test to make it
  easy to detect if this issue reoccurs.

  Then there are a handful of mount and umount related fixes.

  Then half of the changes deal with the a recently discovered design
  bug in the permission checks of gid_map.  Unix since the beginning has
  allowed setting group permissions on files to less than the user and
  other permissions (aka ---rwx---rwx).  As the unix permission checks
  stop as soon as a group matches, and setgroups allows setting groups
  that can not later be dropped, results in a situtation where it is
  possible to legitimately use a group to assign fewer privileges to a
  process.  Which means dropping a group can increase a processes
  privileges.

  The fix I have adopted is that gid_map is now no longer writable
  without privilege unless the new file /proc/self/setgroups has been
  set to permanently disable setgroups.

  The bulk of user namespace using applications even the applications
  using applications using user namespaces without privilege remain
  unaffected by this change.  Unfortunately this ix breaks a couple user
  space applications, that were relying on the problematic behavior (one
  of which was tools/selftests/mount/unprivileged-remount-test.c).

  To hopefully prevent needing a regression fix on top of my security
  fix I rounded folks who work with the container implementations mostly
  like to be affected and encouraged them to test the changes.

    > So far nothing broke on my libvirt-lxc test bed. :-)
    > Tested with openSUSE 13.2 and libvirt 1.2.9.
    > Tested-by: Richard Weinberger <richard@nod.at>

    > Tested on Fedora20 with libvirt 1.2.11, works fine.
    > Tested-by: Chen Hanxiao <chenhanxiao@cn.fujitsu.com>

    > Ok, thanks - yes, unprivileged lxc is working fine with your kernels.
    > Just to be sure I was testing the right thing I also tested using
    > my unprivileged nsexec testcases, and they failed on setgroup/setgid
    > as now expected, and succeeded there without your patches.
    > Tested-by: Serge Hallyn <serge.hallyn@ubuntu.com>

    > I tested this with Sandstorm.  It breaks as is and it works if I add
    > the setgroups thing.
    > Tested-by: Andy Lutomirski <luto@amacapital.net> # breaks things as designed :("

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
  userns: Unbreak the unprivileged remount tests
  userns; Correct the comment in map_write
  userns: Allow setting gid_maps without privilege when setgroups is disabled
  userns: Add a knob to disable setgroups on a per user namespace basis
  userns: Rename id_map_mutex to userns_state_mutex
  userns: Only allow the creator of the userns unprivileged mappings
  userns: Check euid no fsuid when establishing an unprivileged uid mapping
  userns: Don't allow unprivileged creation of gid mappings
  userns: Don't allow setgroups until a gid mapping has been setablished
  userns: Document what the invariant required for safe unprivileged mappings.
  groups: Consolidate the setgroups permission checks
  mnt: Clear mnt_expire during pivot_root
  mnt: Carefully set CL_UNPRIVILEGED in clone_mnt
  mnt: Move the clear of MNT_LOCKED from copy_tree to it's callers.
  umount: Do not allow unmounting rootfs.
  umount: Disallow unprivileged mount force
  mnt: Update unprivileged remount test
  mnt: Implicitly add MNT_NODEV on remount when it was implicitly added by mount
2014-12-17 12:31:40 -08:00
Linus Torvalds
603ba7e41b Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs pile #2 from Al Viro:
 "Next pile (and there'll be one or two more).

  The large piece in this one is getting rid of /proc/*/ns/* weirdness;
  among other things, it allows to (finally) make nameidata completely
  opaque outside of fs/namei.c, making for easier further cleanups in
  there"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  coda_venus_readdir(): use file_inode()
  fs/namei.c: fold link_path_walk() call into path_init()
  path_init(): don't bother with LOOKUP_PARENT in argument
  fs/namei.c: new helper (path_cleanup())
  path_init(): store the "base" pointer to file in nameidata itself
  make default ->i_fop have ->open() fail with ENXIO
  make nameidata completely opaque outside of fs/namei.c
  kill proc_ns completely
  take the targets of /proc/*/ns/* symlinks to separate fs
  bury struct proc_ns in fs/proc
  copy address of proc_ns_ops into ns_common
  new helpers: ns_alloc_inum/ns_free_inum
  make proc_ns_operations work with struct ns_common * instead of void *
  switch the rest of proc_ns_operations to working with &...->ns
  netns: switch ->get()/->put()/->install()/->inum() to working with &net->ns
  make mntns ->get()/->put()/->install()/->inum() work with &mnt_ns->ns
  common object embedded into various struct ....ns
2014-12-16 15:53:03 -08:00
Linus Torvalds
a7c180aa7e As the merge window is still open, and this code was not as complex
as I thought it might be. I'm pushing this in now.
 
 This will allow Thomas to debug his irq work for 3.20.
 
 This adds two new features:
 
 1) Allow traceopoints to be enabled right after mm_init(). By passing
 in the trace_event= kernel command line parameter, tracepoints can be
 enabled at boot up. For debugging things like the initialization of
 interrupts, it is needed to have tracepoints enabled very early. People
 have asked about this before and this has been on my todo list. As it
 can be helpful for Thomas to debug his upcoming 3.20 IRQ work, I'm
 pushing this now. This way he can add tracepoints into the IRQ set up
 and have users enable them when things go wrong.
 
 2) Have the tracepoints printed via printk() (the console) when they
 are triggered. If the irq code locks up or reboots the box, having the
 tracepoint output go into the kernel ring buffer is useless for
 debugging. But being able to add the tp_printk kernel command line
 option along with the trace_event= option will have these tracepoints
 printed as they occur, and that can be really useful for debugging
 early lock up or reboot problems.
 
 This code is not that intrusive and it passed all my tests. Thomas tried
 them out too and it works for his needs.
 
  Link: http://lkml.kernel.org/r/20141214201609.126831471@goodmis.org
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Merge tag 'trace-3.19-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing updates from Steven Rostedt:
 "As the merge window is still open, and this code was not as complex as
  I thought it might be.  I'm pushing this in now.

  This will allow Thomas to debug his irq work for 3.20.

  This adds two new features:

  1) Allow traceopoints to be enabled right after mm_init().

     By passing in the trace_event= kernel command line parameter,
     tracepoints can be enabled at boot up.  For debugging things like
     the initialization of interrupts, it is needed to have tracepoints
     enabled very early.  People have asked about this before and this
     has been on my todo list.  As it can be helpful for Thomas to debug
     his upcoming 3.20 IRQ work, I'm pushing this now.  This way he can
     add tracepoints into the IRQ set up and have users enable them when
     things go wrong.

  2) Have the tracepoints printed via printk() (the console) when they
     are triggered.

     If the irq code locks up or reboots the box, having the tracepoint
     output go into the kernel ring buffer is useless for debugging.
     But being able to add the tp_printk kernel command line option
     along with the trace_event= option will have these tracepoints
     printed as they occur, and that can be really useful for debugging
     early lock up or reboot problems.

  This code is not that intrusive and it passed all my tests.  Thomas
  tried them out too and it works for his needs.

   Link: http://lkml.kernel.org/r/20141214201609.126831471@goodmis.org"

* tag 'trace-3.19-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Add tp_printk cmdline to have tracepoints go to printk()
  tracing: Move enabling tracepoints to just after rcu_init()
2014-12-16 12:53:59 -08:00
Linus Torvalds
988adfdffd Merge branch 'drm-next' of git://people.freedesktop.org/~airlied/linux
Pull drm updates from Dave Airlie:
 "Highlights:

   - AMD KFD driver merge

     This is the AMD HSA interface for exposing a lowlevel interface for
     GPGPU use.  They have an open source userspace built on top of this
     interface, and the code looks as good as it was going to get out of
     tree.

   - Initial atomic modesetting work

     The need for an atomic modesetting interface to allow userspace to
     try and send a complete set of modesetting state to the driver has
     arisen, and been suffering from neglect this past year.  No more,
     the start of the common code and changes for msm driver to use it
     are in this tree.  Ongoing work to get the userspace ioctl finished
     and the code clean will probably wait until next kernel.

   - DisplayID 1.3 and tiled monitor exposed to userspace.

     Tiled monitor property is now exposed for userspace to make use of.

   - Rockchip drm driver merged.

   - imx gpu driver moved out of staging

  Other stuff:

   - core:
        panel - MIPI DSI + new panels.
        expose suggested x/y properties for virtual GPUs

   - i915:
        Initial Skylake (SKL) support
        gen3/4 reset work
        start of dri1/ums removal
        infoframe tracking
        fixes for lots of things.

   - nouveau:
        tegra k1 voltage support
        GM204 modesetting support
        GT21x memory reclocking work

   - radeon:
        CI dpm fixes
        GPUVM improvements
        Initial DPM fan control

   - rcar-du:
        HDMI support added
        removed some support for old boards
        slave encoder driver for Analog Devices adv7511

   - exynos:
        Exynos4415 SoC support

   - msm:
        a4xx gpu support
        atomic helper conversion

   - tegra:
        iommu support
        universal plane support
        ganged-mode DSI support

   - sti:
        HDMI i2c improvements

   - vmwgfx:
        some late fixes.

   - qxl:
        use suggested x/y properties"

* 'drm-next' of git://people.freedesktop.org/~airlied/linux: (969 commits)
  drm: sti: fix module compilation issue
  drm/i915: save/restore GMBUS freq across suspend/resume on gen4
  drm: sti: correctly cleanup CRTC and planes
  drm: sti: add HQVDP plane
  drm: sti: add cursor plane
  drm: sti: enable auxiliary CRTC
  drm: sti: fix delay in VTG programming
  drm: sti: prepare sti_tvout to support auxiliary crtc
  drm: sti: use drm_crtc_vblank_{on/off} instead of drm_vblank_{on/off}
  drm: sti: fix hdmi avi infoframe
  drm: sti: remove event lock while disabling vblank
  drm: sti: simplify gdp code
  drm: sti: clear all mixer control
  drm: sti: remove gpio for HDMI hot plug detection
  drm: sti: allow to change hdmi ddc i2c adapter
  drm/doc: Document drm_add_modes_noedid() usage
  drm/i915: Remove '& 0xffff' from the mask given to WA_REG()
  drm/i915: Invert the mask and val arguments in wa_add() and WA_REG()
  drm: Zero out DRM object memory upon cleanup
  drm/i915/bdw: Fix the write setting up the WIZ hashing mode
  ...
2014-12-15 15:52:01 -08:00
Steven Rostedt (Red Hat)
0daa230296 tracing: Add tp_printk cmdline to have tracepoints go to printk()
Add the kernel command line tp_printk option that will have tracepoints
that are active sent to printk() as well as to the trace buffer.

Passing "tp_printk" will activate this. To turn it off, the sysctl
/proc/sys/kernel/tracepoint_printk can have '0' echoed into it. Note,
this only works if the cmdline option is used. Echoing 1 into the sysctl
file without the cmdline option will have no affect.

Note, this is a dangerous option. Having high frequency tracepoints send
their data to printk() can possibly cause a live lock. This is another
reason why this is only active if the command line option is used.

Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1412121539300.16494@nanos

Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-12-15 10:17:38 -05:00
Steven Rostedt (Red Hat)
5f893b2639 tracing: Move enabling tracepoints to just after rcu_init()
Enabling tracepoints at boot up can be very useful. The tracepoint
can be initialized right after RCU has been. There's no need to
wait for the early_initcall() to be called. That's too late for some
things that can use tracepoints for debugging. Move the logic to
enable tracepoints out of the initcalls and into init/main.c to
right after rcu_init().

This also allows trace_printk() to be used early too.

Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1412121539300.16494@nanos
Link: http://lkml.kernel.org/r/20141214164104.307127356@goodmis.org

Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-12-15 10:16:50 -05:00
Linus Torvalds
37da7bbbe8 TTY/Serial driver patches for 3.19-rc1
Here's the big tty/serial driver update for 3.19-rc1.
 
 There are a number of TTY core changes/fixes in here from Peter Hurley
 that have all been teted in linux-next for a long time now.  There are
 also the normal serial driver updates as well, full details in the
 changelog below.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'tty-3.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

Pull tty/serial driver updates from Greg KH:
 "Here's the big tty/serial driver update for 3.19-rc1.

  There are a number of TTY core changes/fixes in here from Peter Hurley
  that have all been teted in linux-next for a long time now.  There are
  also the normal serial driver updates as well, full details in the
  changelog below"

* tag 'tty-3.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (219 commits)
  serial: pxa: hold port.lock when reporting modem line changes
  tty-hvsi_lib: Deletion of an unnecessary check before the function call "tty_kref_put"
  tty: Deletion of unnecessary checks before two function calls
  n_tty: Fix read_buf race condition, increment read_head after pushing data
  serial: of-serial: add PM suspend/resume support
  Revert "serial: of-serial: add PM suspend/resume support"
  Revert "serial: of-serial: fix up PM ops on no_console_suspend and port type"
  serial: 8250: don't attempt a trylock if in sysrq
  serial: core: Add big-endian iotype
  serial: samsung: use port->fifosize instead of hardcoded values
  serial: samsung: prefer to use fifosize from driver data
  serial: samsung: fix style problems
  serial: samsung: wait for transfer completion before clock disable
  serial: icom: fix error return code
  serial: tegra: clean up tty-flag assignments
  serial: Fix io address assign flow with Fintek PCI-to-UART Product
  serial: mxs-auart: fix tx_empty against shift register
  serial: mxs-auart: fix gpio change detection on interrupt
  serial: mxs-auart: Fix mxs_auart_set_ldisc()
  serial: 8250_dw: Use 64-bit access for OCTEON.
  ...
2014-12-14 15:23:32 -08:00
Linus Torvalds
caf292ae5b Merge branch 'for-3.19/core' of git://git.kernel.dk/linux-block
Pull block driver core update from Jens Axboe:
 "This is the pull request for the core block IO changes for 3.19.  Not
  a huge round this time, mostly lots of little good fixes:

   - Fix a bug in sysfs blktrace interface causing a NULL pointer
     dereference, when enabled/disabled through that API.  From Arianna
     Avanzini.

   - Various updates/fixes/improvements for blk-mq:

        - A set of updates from Bart, mostly fixing buts in the tag
          handling.

        - Cleanup/code consolidation from Christoph.

        - Extend queue_rq API to be able to handle batching issues of IO
          requests. NVMe will utilize this shortly. From me.

        - A few tag and request handling updates from me.

        - Cleanup of the preempt handling for running queues from Paolo.

        - Prevent running of unmapped hardware queues from Ming Lei.

        - Move the kdump memory limiting check to be in the correct
          location, from Shaohua.

        - Initialize all software queues at init time from Takashi. This
          prevents a kobject warning when CPUs are brought online that
          weren't online when a queue was registered.

   - Single writeback fix for I_DIRTY clearing from Tejun.  Queued with
     the core IO changes, since it's just a single fix.

   - Version X of the __bio_add_page() segment addition retry from
     Maurizio.  Hope the Xth time is the charm.

   - Documentation fixup for IO scheduler merging from Jan.

   - Introduce (and use) generic IO stat accounting helpers for non-rq
     drivers, from Gu Zheng.

   - Kill off artificial limiting of max sectors in a request from
     Christoph"

* 'for-3.19/core' of git://git.kernel.dk/linux-block: (26 commits)
  bio: modify __bio_add_page() to accept pages that don't start a new segment
  blk-mq: Fix uninitialized kobject at CPU hotplugging
  blktrace: don't let the sysfs interface remove trace from running list
  blk-mq: Use all available hardware queues
  blk-mq: Micro-optimize bt_get()
  blk-mq: Fix a race between bt_clear_tag() and bt_get()
  blk-mq: Avoid that __bt_get_word() wraps multiple times
  blk-mq: Fix a use-after-free
  blk-mq: prevent unmapped hw queue from being scheduled
  blk-mq: re-check for available tags after running the hardware queue
  blk-mq: fix hang in bt_get()
  blk-mq: move the kdump check to blk_mq_alloc_tag_set
  blk-mq: cleanup tag free handling
  blk-mq: use 'nr_cpu_ids' as highest CPU ID count for hwq <-> cpu map
  blk: introduce generic io stat accounting help function
  blk-mq: handle the single queue case in blk_mq_hctx_next_cpu
  genhd: check for int overflow in disk_expand_part_tbl()
  blk-mq: add blk_mq_free_hctx_request()
  blk-mq: export blk_mq_free_request()
  blk-mq: use get_cpu/put_cpu instead of preempt_disable/preempt_enable
  ...
2014-12-13 14:14:23 -08:00
Linus Torvalds
8f4385d590 This code is a fork from the trace-3.19 pull as it needed the trace_seq
clean ups from that branch.
 
 This code solves the issue of performing stack dumps from NMI context.
 The issue is that printk() is not safe from NMI context as if the NMI
 were to trigger when a printk() was being performed, the NMI could
 deadlock from the printk() internal locks. This has been seen in practice.
 
 With lots of review from Petr Mladek, this code went through several
 iterations, and we feel that it is now at a point of quality to be
 accepted into mainline.
 
 Here's what is contained in this patch set:
 
  o Creates a "seq_buf" generic buffer utility that allows a descriptor
    to be passed around where functions can write their own "printk()"
    formatted strings into it. The generic version was pulled out of
    the trace_seq() code that was made specifically for tracing.
 
  o The seq_buf code was change to model the seq_file code. I have
    a patch (not included for 3.19) that converts the seq_file.c code
    over to use seq_buf.c like the trace_seq.c code does. This was done
    to make sure that seq_buf.c is compatible with seq_file.c. I may
    try to get that patch in for 3.20.
 
  o The seq_buf.c file was moved to lib/ to remove it from being dependent
    on CONFIG_TRACING.
 
  o The printk() was updated to allow for a per_cpu "override" of
    the internal calls. That is, instead of writing to the console, a call
    to printk() may do something else. This made it easier to allow the
    NMI to change what printk() does in order to call dump_stack() without
    needing to update that code as well.
 
  o Finally, the dump_stack from all CPUs via NMI code was converted to
    use the seq_buf code. The caller to trigger the NMI code would wait
    till all the NMIs finished, and then it would print the seq_buf
    data to the console safely from a non NMI context.
 
 [ Updated to remove unnecessary preempt_disable in printk() ]
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Merge tag 'trace-seq-buf-3.19-v2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fixlet from Steven Rostedt:
 "Remove unnecessary preempt_disable in printk()"

* tag 'trace-seq-buf-3.19-v2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  printk: Do not disable preemption for accessing printk_func
2014-12-13 14:04:41 -08:00
Linus Torvalds
a99abce2d9 Merge branch 'upstream' of git://git.infradead.org/users/pcmoore/audit
Pull audit updates from Paul Moore:
 "Two small patches from the audit next branch; only one of which has
  any real significant code changes, the other is simply a MAINTAINERS
  update for audit.

  The single code patch is pretty small and rather straightforward, it
  changes the audit "version" number reported to userspace from an
  integer to a bitmap which is used to indicate the functionality of the
  running kernel.  This really doesn't have much impact on the kernel,
  but it will make life easier for the audit userspace folks.

  Thankfully we were still on a version number which allowed us to do
  this without breaking userspace"

* 'upstream' of git://git.infradead.org/users/pcmoore/audit:
  audit: convert status version to a feature bitmap
  audit: add Paul Moore to the MAINTAINERS entry
2014-12-13 13:41:28 -08:00
Jan Kara
0809ab69a2 fsnotify: unify inode and mount marks handling
There's a lot of common code in inode and mount marks handling.  Factor it
out to a common helper function.

Signed-off-by: Jan Kara <jack@suse.cz>
Cc: Eric Paris <eparis@redhat.com>
Cc: Heinrich Schuchardt <xypron.glpk@gmx.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 12:42:53 -08:00
Riku Voipio
957e3facd1 gcov: enable GCOV_PROFILE_ALL from ARCH Kconfigs
Following the suggestions from Andrew Morton and Stephen Rothwell,
Dont expand the ARCH list in kernel/gcov/Kconfig. Instead,
define a ARCH_HAS_GCOV_PROFILE_ALL bool which architectures
can enable.

set ARCH_HAS_GCOV_PROFILE_ALL on Architectures where it was
previously allowed + ARM64 which I tested.

Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
Cc: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 12:42:51 -08:00
Masanari Iida
d5393955c3 kexec: remove unnecessary KERN_ERR from kexec.c
Remove unnecessary KERN_ERR from pr_err() within kexec.c.

Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 12:42:51 -08:00
David Drysdale
51f39a1f0c syscalls: implement execveat() system call
This patchset adds execveat(2) for x86, and is derived from Meredydd
Luff's patch from Sept 2012 (https://lkml.org/lkml/2012/9/11/528).

The primary aim of adding an execveat syscall is to allow an
implementation of fexecve(3) that does not rely on the /proc filesystem,
at least for executables (rather than scripts).  The current glibc version
of fexecve(3) is implemented via /proc, which causes problems in sandboxed
or otherwise restricted environments.

Given the desire for a /proc-free fexecve() implementation, HPA suggested
(https://lkml.org/lkml/2006/7/11/556) that an execveat(2) syscall would be
an appropriate generalization.

Also, having a new syscall means that it can take a flags argument without
back-compatibility concerns.  The current implementation just defines the
AT_EMPTY_PATH and AT_SYMLINK_NOFOLLOW flags, but other flags could be
added in future -- for example, flags for new namespaces (as suggested at
https://lkml.org/lkml/2006/7/11/474).

Related history:
 - https://lkml.org/lkml/2006/12/27/123 is an example of someone
   realizing that fexecve() is likely to fail in a chroot environment.
 - http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=514043 covered
   documenting the /proc requirement of fexecve(3) in its manpage, to
   "prevent other people from wasting their time".
 - https://bugzilla.redhat.com/show_bug.cgi?id=241609 described a
   problem where a process that did setuid() could not fexecve()
   because it no longer had access to /proc/self/fd; this has since
   been fixed.

This patch (of 4):

Add a new execveat(2) system call.  execveat() is to execve() as openat()
is to open(): it takes a file descriptor that refers to a directory, and
resolves the filename relative to that.

In addition, if the filename is empty and AT_EMPTY_PATH is specified,
execveat() executes the file to which the file descriptor refers.  This
replicates the functionality of fexecve(), which is a system call in other
UNIXen, but in Linux glibc it depends on opening "/proc/self/fd/<fd>" (and
so relies on /proc being mounted).

The filename fed to the executed program as argv[0] (or the name of the
script fed to a script interpreter) will be of the form "/dev/fd/<fd>"
(for an empty filename) or "/dev/fd/<fd>/<filename>", effectively
reflecting how the executable was found.  This does however mean that
execution of a script in a /proc-less environment won't work; also, script
execution via an O_CLOEXEC file descriptor fails (as the file will not be
accessible after exec).

Based on patches by Meredydd Luff.

Signed-off-by: David Drysdale <drysdale@google.com>
Cc: Meredydd Luff <meredydd@senatehouse.org>
Cc: Shuah Khan <shuah.kh@samsung.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Rich Felker <dalias@aerifal.cx>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 12:42:51 -08:00
Joonsoo Kim
9a92a6ce6f stacktrace: introduce snprint_stack_trace for buffer output
Current stacktrace only have the function for console output.  page_owner
that will be introduced in following patch needs to print the output of
stacktrace into the buffer for our own output format so so new function,
snprint_stack_trace(), is needed.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Dave Hansen <dave@sr71.net>
Cc: Michal Nazarewicz <mina86@mina86.com>
Cc: Jungsoo Son <jungsoo.son@lge.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 12:42:48 -08:00
Davidlohr Bueso
4a23717a23 uprobes: share the i_mmap_rwsem
Both register and unregister call build_map_info() in order to create the
list of mappings before installing or removing breakpoints for every mm
which maps file backed memory.  As such, there is no reason to hold the
i_mmap_rwsem exclusively, so share it and allow concurrent readers to
build the mapping data.

Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Acked-by: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Oleg Nesterov <oleg@redhat.com>
Acked-by: Hugh Dickins <hughd@google.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 12:42:45 -08:00
Davidlohr Bueso
c8c06efa8b mm: convert i_mmap_mutex to rwsem
The i_mmap_mutex is a close cousin of the anon vma lock, both protecting
similar data, one for file backed pages and the other for anon memory.  To
this end, this lock can also be a rwsem.  In addition, there are some
important opportunities to share the lock when there are no tree
modifications.

This conversion is straightforward.  For now, all users take the write
lock.

[sfr@canb.auug.org.au: update fremap.c]
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Reviewed-by: Rik van Riel <riel@redhat.com>
Acked-by: "Kirill A. Shutemov" <kirill@shutemov.name>
Acked-by: Hugh Dickins <hughd@google.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 12:42:45 -08:00
Davidlohr Bueso
83cde9e8ba mm: use new helper functions around the i_mmap_mutex
Convert all open coded mutex_lock/unlock calls to the
i_mmap_[lock/unlock]_write() helpers.

Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: "Kirill A. Shutemov" <kirill@shutemov.name>
Acked-by: Hugh Dickins <hughd@google.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 12:42:45 -08:00
Thomas Gleixner
c291ee6221 genirq: Prevent proc race against freeing of irq descriptors
Since the rework of the sparse interrupt code to actually free the
unused interrupt descriptors there exists a race between the /proc
interfaces to the irq subsystem and the code which frees the interrupt
descriptor.

CPU0				CPU1
				show_interrupts()
				  desc = irq_to_desc(X);
free_desc(desc)
  remove_from_radix_tree();
  kfree(desc);
				  raw_spinlock_irq(&desc->lock);

/proc/interrupts is the only interface which can actively corrupt
kernel memory via the lock access. /proc/stat can only read from freed
memory. Extremly hard to trigger, but possible.

The interfaces in /proc/irq/N/ are not affected by this because the
removal of the proc file is serialized in procfs against concurrent
readers/writers. The removal happens before the descriptor is freed.

For architectures which have CONFIG_SPARSE_IRQ=n this is a non issue
as the descriptor is never freed. It's merely cleared out with the irq
descriptor lock held. So any concurrent proc access will either see
the old correct value or the cleared out ones.

Protect the lookup and access to the irq descriptor in
show_interrupts() with the sparse_irq_lock.

Provide kstat_irqs_usr() which is protecting the lookup and access
with sparse_irq_lock and switch /proc/stat to use it.

Document the existing kstat_irqs interfaces so it's clear that the
caller needs to take care about protection. The users of these
interfaces are either not affected due to SPARSE_IRQ=n or already
protected against removal.

Fixes: 1f5a5b87f7 "genirq: Implement a sane sparse_irq allocator"
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
2014-12-13 13:33:07 +01:00
Rafael J. Wysocki
798bc6d8d5 tracing / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
After commit b2b49ccbdd (PM: Kconfig: Set PM_RUNTIME if PM_SLEEP is
selected) PM_RUNTIME is always set if PM is set, so files that are
build conditionally if CONFIG_PM_RUNTIME is set may now be build
if CONFIG_PM is set.

Replace CONFIG_PM_RUNTIME with CONFIG_PM in kernel/trace/Makefile
for this reason.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org.
2014-12-13 02:23:30 +01:00
Linus Torvalds
a7cb7bb664 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial
Pull trivial tree update from Jiri Kosina:
 "Usual stuff: documentation updates, printk() fixes, etc"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (24 commits)
  intel_ips: fix a type in error message
  cpufreq: cpufreq-dt: Move newline to end of error message
  ps3rom: fix error return code
  treewide: fix typo in printk and Kconfig
  ARM: dts: bcm63138: change "interupts" to "interrupts"
  Replace mentions of "list_struct" to "list_head"
  kernel: trace: fix printk message
  scsi: mpt2sas: fix ioctl in comment
  zbud, zswap: change module author email
  clocksource: Fix 'clcoksource' typo in comment
  arm: fix wording of "Crotex" in CONFIG_ARCH_EXYNOS3 help
  gpio: msm-v1: make boolean argument more obvious
  usb: Fix typo in usb-serial-simple.c
  PCI: Fix comment typo 'COMFIG_PM_OPS'
  powerpc: Fix comment typo 'CONIFG_8xx'
  powerpc: Fix comment typos 'CONFiG_ALTIVEC'
  clk: st: Spelling s/stucture/structure/
  isci: Spelling s/stucture/structure/
  usb: gadget: zero: Spelling s/infrastucture/infrastructure/
  treewide: Fix company name in module descriptions
  ...
2014-12-12 10:08:06 -08:00
Ingo Molnar
3459f0d78f Merge branch 'linus' into perf/urgent, to pick up the upstream merged bits
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-12-12 09:09:03 +01:00
Linus Torvalds
2756d373a3 Merge branch 'for-3.19' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup update from Tejun Heo:
 "cpuset got simplified a bit.  cgroup core got a fix on unified
  hierarchy and grew some effective css related interfaces which will be
  used for blkio support for writeback IO traffic which is currently
  being worked on"

* 'for-3.19' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  cgroup: implement cgroup_get_e_css()
  cgroup: add cgroup_subsys->css_e_css_changed()
  cgroup: add cgroup_subsys->css_released()
  cgroup: fix the async css offline wait logic in cgroup_subtree_control_write()
  cgroup: restructure child_subsys_mask handling in cgroup_subtree_control_write()
  cgroup: separate out cgroup_calc_child_subsys_mask() from cgroup_refresh_child_subsys_mask()
  cpuset: lock vs unlock typo
  cpuset: simplify cpuset_node_allowed API
  cpuset: convert callback_mutex to a spinlock
2014-12-11 18:57:19 -08:00
Linus Torvalds
0a27044c83 Merge branch 'for-3.19' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq
Pull workqueue update from Tejun Heo:
 "Work items which may be involved in memory reclaim path may be
  executed by the rescuer under memory pressure.  When a rescuer gets
  activated, it processes whatever are on the pending list and then goes
  back to sleep until the manager kicks it again which involves 100ms
  delay.

  This is problematic for self-requeueing work items or the ones running
  on ordered workqueues as there always is only one work item on the
  pending list when the rescuer kicks in.  The execution of that work
  item produces more to execute but the rescuer won't see them until
  after the said 100ms has passed, so such workqueues would only execute
  one work item every 100ms under prolonged memory pressure, which BTW
  may be being prolonged due to the slow execution.

  Neil wrote up a patch which fixes this issue by keeping the rescuer
  working as long as the target workqueue is busy but doesn't have
  enough workers"

* 'for-3.19' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
  workqueue: allow rescuer thread to do more work.
  workqueue: invert the order between pool->lock and wq_mayday_lock
  workqueue: cosmetic update in rescuer_thread()
2014-12-11 18:48:45 -08:00
Linus Torvalds
eedb3d3304 Merge branch 'for-3.19' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu
Pull percpu updates from Tejun Heo:
 "Nothing interesting.  A patch to convert the remaining __get_cpu_var()
  users, another to fix non-critical off-by-one in an assertion and a
  cosmetic conversion to lockless_dereference() in percpu-ref.

  The back-merge from mainline is to receive lockless_dereference()"

* 'for-3.19' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu:
  percpu: Replace smp_read_barrier_depends() with lockless_dereference()
  percpu: Convert remaining __get_cpu_var uses in 3.18-rcX
  percpu: off by one in BUG_ON()
2014-12-11 18:36:26 -08:00
Dave Airlie
b59f78228c Merge tag 'drm-intel-next-fixes-2014-12-11' of git://anongit.freedesktop.org/drm-intel into drm-next
Here's a batch of i915 fixes for 3.19.

* tag 'drm-intel-next-fixes-2014-12-11' of git://anongit.freedesktop.org/drm-intel:
  drm/i915: save/restore GMBUS freq across suspend/resume on gen4
  drm/i915: Remove '& 0xffff' from the mask given to WA_REG()
  drm/i915: Invert the mask and val arguments in wa_add() and WA_REG()
  drm/i915/bdw: Fix the write setting up the WIZ hashing mode
  drm/i915: Don't complain about stolen conflicts on gen3
  drm/i915: resume MST after reading back hw state
  drm/i915: Handle inaccurate time conversion issues
  drm/i915: compute wait_ioctl timeout correctly
  drm/i915: don't always do full mode sets when infoframes are enabled
2014-12-12 11:39:49 +10:00
Linus Torvalds
27afc5dbda Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux
Pull s390 updates from Martin Schwidefsky:
 "The most notable change for this pull request is the ftrace rework
  from Heiko.  It brings a small performance improvement and the ground
  work to support a new gcc option to replace the mcount blocks with a
  single nop.

  Two new s390 specific system calls are added to emulate user space
  mmio for PCI, an artifact of the how PCI memory is accessed.

  Two patches for the memory management with changes to common code.
  For KVM mm_forbids_zeropage is added which disables the empty zero
  page for an mm that is used by a KVM process.  And an optimization,
  pmdp_get_and_clear_full is added analog to ptep_get_and_clear_full.

  Some micro optimization for the cmpxchg and the spinlock code.

  And as usual bug fixes and cleanups"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (46 commits)
  s390/cputime: fix 31-bit compile
  s390/scm_block: make the number of reqs per HW req configurable
  s390/scm_block: handle multiple requests in one HW request
  s390/scm_block: allocate aidaw pages only when necessary
  s390/scm_block: use mempool to manage aidaw requests
  s390/eadm: change timeout value
  s390/mm: fix memory leak of ptlock in pmd_free_tlb
  s390: use local symbol names in entry[64].S
  s390/ptrace: always include vector registers in core files
  s390/simd: clear vector register pointer on fork/clone
  s390: translate cputime magic constants to macros
  s390/idle: convert open coded idle time seqcount
  s390/idle: add missing irq off lockdep annotation
  s390/debug: avoid function call for debug_sprintf_*
  s390/kprobes: fix instruction copy for out of line execution
  s390: remove diag 44 calls from cpu_relax()
  s390/dasd: retry partition detection
  s390/dasd: fix list corruption for sleep_on requests
  s390/dasd: fix infinite term I/O loop
  s390/dasd: remove unused code
  ...
2014-12-11 17:30:55 -08:00
Eric W. Biederman
36476beac4 userns; Correct the comment in map_write
It is important that all maps are less than PAGE_SIZE
or else setting the last byte of the buffer to '0'
could write off the end of the allocated storage.

Correct the misleading comment.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2014-12-11 18:07:06 -06:00
Eric W. Biederman
66d2f338ee userns: Allow setting gid_maps without privilege when setgroups is disabled
Now that setgroups can be disabled and not reenabled, setting gid_map
without privielge can now be enabled when setgroups is disabled.

This restores most of the functionality that was lost when unprivileged
setting of gid_map was removed.  Applications that use this functionality
will need to check to see if they use setgroups or init_groups, and if they
don't they can be fixed by simply disabling setgroups before writing to
gid_map.

Cc: stable@vger.kernel.org
Reviewed-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2014-12-11 18:07:06 -06:00
Eric W. Biederman
9cc46516dd userns: Add a knob to disable setgroups on a per user namespace basis
- Expose the knob to user space through a proc file /proc/<pid>/setgroups

  A value of "deny" means the setgroups system call is disabled in the
  current processes user namespace and can not be enabled in the
  future in this user namespace.

  A value of "allow" means the segtoups system call is enabled.

- Descendant user namespaces inherit the value of setgroups from
  their parents.

- A proc file is used (instead of a sysctl) as sysctls currently do
  not allow checking the permissions at open time.

- Writing to the proc file is restricted to before the gid_map
  for the user namespace is set.

  This ensures that disabling setgroups at a user namespace
  level will never remove the ability to call setgroups
  from a process that already has that ability.

  A process may opt in to the setgroups disable for itself by
  creating, entering and configuring a user namespace or by calling
  setns on an existing user namespace with setgroups disabled.
  Processes without privileges already can not call setgroups so this
  is a noop.  Prodcess with privilege become processes without
  privilege when entering a user namespace and as with any other path
  to dropping privilege they would not have the ability to call
  setgroups.  So this remains within the bounds of what is possible
  without a knob to disable setgroups permanently in a user namespace.

Cc: stable@vger.kernel.org
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2014-12-11 18:06:36 -06:00
Linus Torvalds
70e71ca0af Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next
Pull networking updates from David Miller:

 1) New offloading infrastructure and example 'rocker' driver for
    offloading of switching and routing to hardware.

    This work was done by a large group of dedicated individuals, not
    limited to: Scott Feldman, Jiri Pirko, Thomas Graf, John Fastabend,
    Jamal Hadi Salim, Andy Gospodarek, Florian Fainelli, Roopa Prabhu

 2) Start making the networking operate on IOV iterators instead of
    modifying iov objects in-situ during transfers.  Thanks to Al Viro
    and Herbert Xu.

 3) A set of new netlink interfaces for the TIPC stack, from Richard
    Alpe.

 4) Remove unnecessary looping during ipv6 routing lookups, from Martin
    KaFai Lau.

 5) Add PAUSE frame generation support to gianfar driver, from Matei
    Pavaluca.

 6) Allow for larger reordering levels in TCP, which are easily
    achievable in the real world right now, from Eric Dumazet.

 7) Add a variable of napi_schedule that doesn't need to disable cpu
    interrupts, from Eric Dumazet.

 8) Use a doubly linked list to optimize neigh_parms_release(), from
    Nicolas Dichtel.

 9) Various enhancements to the kernel BPF verifier, and allow eBPF
    programs to actually be attached to sockets.  From Alexei
    Starovoitov.

10) Support TSO/LSO in sunvnet driver, from David L Stevens.

11) Allow controlling ECN usage via routing metrics, from Florian
    Westphal.

12) Remote checksum offload, from Tom Herbert.

13) Add split-header receive, BQL, and xmit_more support to amd-xgbe
    driver, from Thomas Lendacky.

14) Add MPLS support to openvswitch, from Simon Horman.

15) Support wildcard tunnel endpoints in ipv6 tunnels, from Steffen
    Klassert.

16) Do gro flushes on a per-device basis using a timer, from Eric
    Dumazet.  This tries to resolve the conflicting goals between the
    desired handling of bulk vs.  RPC-like traffic.

17) Allow userspace to ask for the CPU upon what a packet was
    received/steered, via SO_INCOMING_CPU.  From Eric Dumazet.

18) Limit GSO packets to half the current congestion window, from Eric
    Dumazet.

19) Add a generic helper so that all drivers set their RSS keys in a
    consistent way, from Eric Dumazet.

20) Add xmit_more support to enic driver, from Govindarajulu
    Varadarajan.

21) Add VLAN packet scheduler action, from Jiri Pirko.

22) Support configurable RSS hash functions via ethtool, from Eyal
    Perry.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1820 commits)
  Fix race condition between vxlan_sock_add and vxlan_sock_release
  net/macb: fix compilation warning for print_hex_dump() called with skb->mac_header
  net/mlx4: Add support for A0 steering
  net/mlx4: Refactor QUERY_PORT
  net/mlx4_core: Add explicit error message when rule doesn't meet configuration
  net/mlx4: Add A0 hybrid steering
  net/mlx4: Add mlx4_bitmap zone allocator
  net/mlx4: Add a check if there are too many reserved QPs
  net/mlx4: Change QP allocation scheme
  net/mlx4_core: Use tasklet for user-space CQ completion events
  net/mlx4_core: Mask out host side virtualization features for guests
  net/mlx4_en: Set csum level for encapsulated packets
  be2net: Export tunnel offloads only when a VxLAN tunnel is created
  gianfar: Fix dma check map error when DMA_API_DEBUG is enabled
  cxgb4/csiostor: Don't use MASTER_MUST for fw_hello call
  net: fec: only enable mdio interrupt before phy device link up
  net: fec: clear all interrupt events to support i.MX6SX
  net: fec: reset fep link status in suspend function
  net: sock: fix access via invalid file descriptor
  net: introduce helper macro for_each_cmsghdr
  ...
2014-12-11 14:27:06 -08:00
Steven Rostedt (Red Hat)
1fb8915b98 printk: Do not disable preemption for accessing printk_func
As printk_func will either be the default function, or a per_cpu function
for the current CPU, there's no reason to disable preemption to access
it from printk. That's because if the printk_func is not the default
then the caller had better disabled preemption as they were the one to
change it.

Link: http://lkml.kernel.org/r/CA+55aFz5-_LKW4JHEBoWinN9_ouNcGRWAF2FUA35u46FRN-Kxw@mail.gmail.com

Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-12-11 09:12:01 -05:00
Jiri Olsa
9fc81d8742 perf: Fix events installation during moving group
We allow PMU driver to change the cpu on which the event
should be installed to. This happened in patch:

  e2d37cd213 ("perf: Allow the PMU driver to choose the CPU on which to install events")

This patch also forces all the group members to follow
the currently opened events cpu if the group happened
to be moved.

This and the change of event->cpu in perf_install_in_context()
function introduced in:

  0cda4c0231 ("perf: Introduce perf_pmu_migrate_context()")

forces group members to change their event->cpu,
if the currently-opened-event's PMU changed the cpu
and there is a group move.

Above behaviour causes problem for breakpoint events,
which uses event->cpu to touch cpu specific data for
breakpoints accounting. By changing event->cpu, some
breakpoints slots were wrongly accounted for given
cpu.

Vinces's perf fuzzer hit this issue and caused following
WARN on my setup:

   WARNING: CPU: 0 PID: 20214 at arch/x86/kernel/hw_breakpoint.c:119 arch_install_hw_breakpoint+0x142/0x150()
   Can't find any breakpoint slot
   [...]

This patch changes the group moving code to keep the event's
original cpu.

Reported-by: Vince Weaver <vince@deater.net>
Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Vince Weaver <vince@deater.net>
Cc: Yan, Zheng <zheng.z.yan@intel.com>
Cc: <stable@vger.kernel.org>
Link: http://lkml.kernel.org/r/1418243031-20367-3-git-send-email-jolsa@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-12-11 11:24:15 +01:00
Linus Torvalds
92a578b064 ACPI and power management updates for 3.19-rc1
This time we have some more new material than we used to have during
 the last couple of development cycles.
 
 The most important part of it to me is the introduction of a unified
 interface for accessing device properties provided by platform
 firmware.  It works with Device Trees and ACPI in a uniform way and
 drivers using it need not worry about where the properties come
 from as long as the platform firmware (either DT or ACPI) makes
 them available.  It covers both devices and "bare" device node
 objects without struct device representation as that turns out to
 be necessary in some cases.  This has been in the works for quite
 a few months (and development cycles) and has been approved by
 all of the relevant maintainers.
 
 On top of that, some drivers are switched over to the new interface
 (at25, leds-gpio, gpio_keys_polled) and some additional changes are
 made to the core GPIO subsystem to allow device drivers to manipulate
 GPIOs in the "canonical" way on platforms that provide GPIO information
 in their ACPI tables, but don't assign names to GPIO lines (in which
 case the driver needs to do that on the basis of what it knows about
 the device in question).  That also has been approved by the GPIO
 core maintainers and the rfkill driver is now going to use it.
 
 Second is support for hardware P-states in the intel_pstate driver.
 It uses CPUID to detect whether or not the feature is supported by
 the processor in which case it will be enabled by default.  However,
 it can be disabled entirely from the kernel command line if necessary.
 
 Next is support for a platform firmware interface based on ACPI
 operation regions used by the PMIC (Power Management Integrated
 Circuit) chips on the Intel Baytrail-T and Baytrail-T-CR platforms.
 That interface is used for manipulating power resources and for
 thermal management: sensor temperature reporting, trip point setting
 and so on.
 
 Also the ACPI core is now going to support the _DEP configuration
 information in a limited way.  Basically, _DEP it supposed to reflect
 off-the-hierarchy dependencies between devices which may be very
 indirect, like when AML for one device accesses locations in an
 operation region handled by another device's driver (usually, the
 device depended on this way is a serial bus or GPIO controller).
 The support added this time is sufficient to make the ACPI battery
 driver work on Asus T100A, but it is general enough to be able to
 cover some other use cases in the future.
 
 Finally, we have a new cpufreq driver for the Loongson1B processor.
 
 In addition to the above, there are fixes and cleanups all over the
 place as usual and a traditional ACPICA update to a recent upstream
 release.
 
 As far as the fixes go, the ACPI LPSS (Low-power Subsystem) driver
 for Intel platforms should be able to handle power management of
 the DMA engine correctly, the cpufreq-dt driver should interact
 with the thermal subsystem in a better way and the ACPI backlight
 driver should handle some more corner cases, among other things.
 
 On top of the ACPICA update there are fixes for race conditions
 in the ACPICA's interrupt handling code which might lead to some
 random and strange looking failures on some systems.
 
 In the cleanups department the most visible part is the series
 of commits targeted at getting rid of the CONFIG_PM_RUNTIME
 configuration option.  That was triggered by a discussion
 regarding the generic power domains code during which we realized
 that trying to support certain combinations of PM config options
 was painful and not really worth it, because nobody would use them
 in production anyway.  For this reason, we decided to make
 CONFIG_PM_SLEEP select CONFIG_PM_RUNTIME and that lead to the
 conclusion that the latter became redundant and CONFIG_PM could
 be used instead of it.  The material here makes that replacement
 in a major part of the tree, but there will be at least one more
 batch of that in the second part of the merge window.
 
 Specifics:
 
  - Support for retrieving device properties information from ACPI
    _DSD device configuration objects and a unified device properties
    interface for device drivers (and subsystems) on top of that.
    As stated above, this works with Device Trees and ACPI and allows
    device drivers to be written in a platform firmware (DT or ACPI)
    agnostic way.  The at25, leds-gpio and gpio_keys_polled drivers
    are now going to use this new interface and the GPIO subsystem
    is additionally modified to allow device drivers to assign names
    to GPIO resources returned by ACPI _CRS objects (in case _DSD is
    not present or does not provide the expected data).  The changes
    in this set are mostly from Mika Westerberg, Rafael J Wysocki,
    Aaron Lu, and Darren Hart with some fixes from others (Fabio Estevam,
    Geert Uytterhoeven).
 
  - Support for Hardware Managed Performance States (HWP) as described
    in Volume 3, section 14.4, of the Intel SDM in the intel_pstate
    driver.  CPUID is used to detect whether or not the feature is
    supported by the processor.  If supported, it will be enabled
    automatically unless the intel_pstate=no_hwp switch is present in
    the kernel command line.  From Dirk Brandewie.
 
  - New Intel Broadwell-H ID for intel_pstate (Dirk Brandewie).
 
  - Support for firmware interface based on ACPI operation regions
    used by the PMIC chips on the Intel Baytrail-T and Baytrail-T-CR
    platforms for power resource control and thermal management
    (Aaron Lu).
 
  - Limited support for retrieving off-the-hierarchy dependencies
    between devices from ACPI _DEP device configuration objects
    and deferred probing support for the ACPI battery driver based
    on the _DEP information to make that driver work on Asus T100A
    (Lan Tianyu).
 
  - New cpufreq driver for the Loongson1B processor (Kelvin Cheung).
 
  - ACPICA update to upstream revision 20141107 which only affects
    tools (Bob Moore).
 
  - Fixes for race conditions in the ACPICA's interrupt handling
    code and in the ACPI code related to system suspend and resume
    (Lv Zheng and Rafael J Wysocki).
 
  - ACPI core fix for an RCU-related issue in the ioremap() regions
    management code that slowed down significantly after CPUs had
    been allowed to enter idle states even if they'd had RCU callbakcs
    queued and triggered some problems in certain proprietary graphics
    driver (and elsewhere).  The fix replaces synchronize_rcu() in
    that code with synchronize_rcu_expedited() which makes the issue
    go away.  From Konstantin Khlebnikov.
 
  - ACPI LPSS (Low-Power Subsystem) driver fix to handle power
    management of the DMA engine included into the LPSS correctly.
    The problem is that the DMA engine doesn't have ACPI PM support
    of its own and it simply is turned off when the last LPSS device
    having ACPI PM support goes into D3cold.  To work around that,
    the PM domain used by the ACPI LPSS driver is redesigned so at
    least one device with ACPI PM support will be on as long as the
    DMA engine is in use.  From Andy Shevchenko.
 
  - ACPI backlight driver fix to avoid using it on "Win8-compatible"
    systems where it doesn't work and where it was used by default by
    mistake (Aaron Lu).
 
  - Assorted minor ACPI core fixes and cleanups from Tomasz Nowicki,
    Sudeep Holla, Huang Rui, Hanjun Guo, Fabian Frederick, and
    Ashwin Chaugule (mostly related to the upcoming ARM64 support).
 
  - Intel RAPL (Running Average Power Limit) power capping driver
    fixes and improvements including new processor IDs (Jacob Pan).
 
  - Generic power domains modification to power up domains after
    attaching devices to them to meet the expectations of device
    drivers and bus types assuming devices to be accessible at
    probe time (Ulf Hansson).
 
  - Preliminary support for controlling device clocks from the
    generic power domains core code and modifications of the
    ARM/shmobile platform to use that feature (Ulf Hansson).
 
  - Assorted minor fixes and cleanups of the generic power
    domains core code (Ulf Hansson, Geert Uytterhoeven).
 
  - Assorted minor fixes and cleanups of the device clocks control
    code in the PM core (Geert Uytterhoeven, Grygorii Strashko).
 
  - Consolidation of device power management Kconfig options by making
    CONFIG_PM_SLEEP select CONFIG_PM_RUNTIME and removing the latter
    which is now redundant (Rafael J Wysocki and Kevin Hilman).  That
    is the first batch of the changes needed for this purpose.
 
  - Core device runtime power management support code cleanup related
    to the execution of callbacks (Andrzej Hajda).
 
  - cpuidle ARM support improvements (Lorenzo Pieralisi).
 
  - cpuidle cleanup related to the CPUIDLE_FLAG_TIME_VALID flag and
    a new MAINTAINERS entry for ARM Exynos cpuidle (Daniel Lezcano and
    Bartlomiej Zolnierkiewicz).
 
  - New cpufreq driver callback (->ready) to be executed when the
    cpufreq core is ready to use a given policy object and cpufreq-dt
    driver modification to use that callback for cooling device
    registration (Viresh Kumar).
 
  - cpufreq core fixes and cleanups (Viresh Kumar, Vince Hsu,
    James Geboski, Tomeu Vizoso).
 
  - Assorted fixes and cleanups in the cpufreq-pcc, intel_pstate,
    cpufreq-dt, pxa2xx cpufreq drivers (Lenny Szubowicz, Ethan Zhao,
    Stefan Wahren, Petr Cvek).
 
  - OPP (Operating Performance Points) framework modification to
    allow OPPs to be removed too and update of a few cpufreq drivers
    (cpufreq-dt, exynos5440, imx6q, cpufreq) to remove OPPs (added
    during initialization) on driver removal (Viresh Kumar).
 
  - Hibernation core fixes and cleanups (Tina Ruchandani and
    Markus Elfring).
 
  - PM Kconfig fix related to CPU power management (Pankaj Dubey).
 
  - cpupower tool fix (Prarit Bhargava).
 
 /
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Merge tag 'pm+acpi-3.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull ACPI and power management updates from Rafael Wysocki:
 "This time we have some more new material than we used to have during
  the last couple of development cycles.

  The most important part of it to me is the introduction of a unified
  interface for accessing device properties provided by platform
  firmware.  It works with Device Trees and ACPI in a uniform way and
  drivers using it need not worry about where the properties come from
  as long as the platform firmware (either DT or ACPI) makes them
  available.  It covers both devices and "bare" device node objects
  without struct device representation as that turns out to be necessary
  in some cases.  This has been in the works for quite a few months (and
  development cycles) and has been approved by all of the relevant
  maintainers.

  On top of that, some drivers are switched over to the new interface
  (at25, leds-gpio, gpio_keys_polled) and some additional changes are
  made to the core GPIO subsystem to allow device drivers to manipulate
  GPIOs in the "canonical" way on platforms that provide GPIO
  information in their ACPI tables, but don't assign names to GPIO lines
  (in which case the driver needs to do that on the basis of what it
  knows about the device in question).  That also has been approved by
  the GPIO core maintainers and the rfkill driver is now going to use
  it.

  Second is support for hardware P-states in the intel_pstate driver.
  It uses CPUID to detect whether or not the feature is supported by the
  processor in which case it will be enabled by default.  However, it
  can be disabled entirely from the kernel command line if necessary.

  Next is support for a platform firmware interface based on ACPI
  operation regions used by the PMIC (Power Management Integrated
  Circuit) chips on the Intel Baytrail-T and Baytrail-T-CR platforms.
  That interface is used for manipulating power resources and for
  thermal management: sensor temperature reporting, trip point setting
  and so on.

  Also the ACPI core is now going to support the _DEP configuration
  information in a limited way.  Basically, _DEP it supposed to reflect
  off-the-hierarchy dependencies between devices which may be very
  indirect, like when AML for one device accesses locations in an
  operation region handled by another device's driver (usually, the
  device depended on this way is a serial bus or GPIO controller).  The
  support added this time is sufficient to make the ACPI battery driver
  work on Asus T100A, but it is general enough to be able to cover some
  other use cases in the future.

  Finally, we have a new cpufreq driver for the Loongson1B processor.

  In addition to the above, there are fixes and cleanups all over the
  place as usual and a traditional ACPICA update to a recent upstream
  release.

  As far as the fixes go, the ACPI LPSS (Low-power Subsystem) driver for
  Intel platforms should be able to handle power management of the DMA
  engine correctly, the cpufreq-dt driver should interact with the
  thermal subsystem in a better way and the ACPI backlight driver should
  handle some more corner cases, among other things.

  On top of the ACPICA update there are fixes for race conditions in the
  ACPICA's interrupt handling code which might lead to some random and
  strange looking failures on some systems.

  In the cleanups department the most visible part is the series of
  commits targeted at getting rid of the CONFIG_PM_RUNTIME configuration
  option.  That was triggered by a discussion regarding the generic
  power domains code during which we realized that trying to support
  certain combinations of PM config options was painful and not really
  worth it, because nobody would use them in production anyway.  For
  this reason, we decided to make CONFIG_PM_SLEEP select
  CONFIG_PM_RUNTIME and that lead to the conclusion that the latter
  became redundant and CONFIG_PM could be used instead of it.  The
  material here makes that replacement in a major part of the tree, but
  there will be at least one more batch of that in the second part of
  the merge window.

  Specifics:

   - Support for retrieving device properties information from ACPI _DSD
     device configuration objects and a unified device properties
     interface for device drivers (and subsystems) on top of that.  As
     stated above, this works with Device Trees and ACPI and allows
     device drivers to be written in a platform firmware (DT or ACPI)
     agnostic way.  The at25, leds-gpio and gpio_keys_polled drivers are
     now going to use this new interface and the GPIO subsystem is
     additionally modified to allow device drivers to assign names to
     GPIO resources returned by ACPI _CRS objects (in case _DSD is not
     present or does not provide the expected data).  The changes in
     this set are mostly from Mika Westerberg, Rafael J Wysocki, Aaron
     Lu, and Darren Hart with some fixes from others (Fabio Estevam,
     Geert Uytterhoeven).

   - Support for Hardware Managed Performance States (HWP) as described
     in Volume 3, section 14.4, of the Intel SDM in the intel_pstate
     driver.  CPUID is used to detect whether or not the feature is
     supported by the processor.  If supported, it will be enabled
     automatically unless the intel_pstate=no_hwp switch is present in
     the kernel command line.  From Dirk Brandewie.

   - New Intel Broadwell-H ID for intel_pstate (Dirk Brandewie).

   - Support for firmware interface based on ACPI operation regions used
     by the PMIC chips on the Intel Baytrail-T and Baytrail-T-CR
     platforms for power resource control and thermal management (Aaron
     Lu).

   - Limited support for retrieving off-the-hierarchy dependencies
     between devices from ACPI _DEP device configuration objects and
     deferred probing support for the ACPI battery driver based on the
     _DEP information to make that driver work on Asus T100A (Lan
     Tianyu).

   - New cpufreq driver for the Loongson1B processor (Kelvin Cheung).

   - ACPICA update to upstream revision 20141107 which only affects
     tools (Bob Moore).

   - Fixes for race conditions in the ACPICA's interrupt handling code
     and in the ACPI code related to system suspend and resume (Lv Zheng
     and Rafael J Wysocki).

   - ACPI core fix for an RCU-related issue in the ioremap() regions
     management code that slowed down significantly after CPUs had been
     allowed to enter idle states even if they'd had RCU callbakcs
     queued and triggered some problems in certain proprietary graphics
     driver (and elsewhere).  The fix replaces synchronize_rcu() in that
     code with synchronize_rcu_expedited() which makes the issue go
     away.  From Konstantin Khlebnikov.

   - ACPI LPSS (Low-Power Subsystem) driver fix to handle power
     management of the DMA engine included into the LPSS correctly.  The
     problem is that the DMA engine doesn't have ACPI PM support of its
     own and it simply is turned off when the last LPSS device having
     ACPI PM support goes into D3cold.  To work around that, the PM
     domain used by the ACPI LPSS driver is redesigned so at least one
     device with ACPI PM support will be on as long as the DMA engine is
     in use.  From Andy Shevchenko.

   - ACPI backlight driver fix to avoid using it on "Win8-compatible"
     systems where it doesn't work and where it was used by default by
     mistake (Aaron Lu).

   - Assorted minor ACPI core fixes and cleanups from Tomasz Nowicki,
     Sudeep Holla, Huang Rui, Hanjun Guo, Fabian Frederick, and Ashwin
     Chaugule (mostly related to the upcoming ARM64 support).

   - Intel RAPL (Running Average Power Limit) power capping driver fixes
     and improvements including new processor IDs (Jacob Pan).

   - Generic power domains modification to power up domains after
     attaching devices to them to meet the expectations of device
     drivers and bus types assuming devices to be accessible at probe
     time (Ulf Hansson).

   - Preliminary support for controlling device clocks from the generic
     power domains core code and modifications of the ARM/shmobile
     platform to use that feature (Ulf Hansson).

   - Assorted minor fixes and cleanups of the generic power domains core
     code (Ulf Hansson, Geert Uytterhoeven).

   - Assorted minor fixes and cleanups of the device clocks control code
     in the PM core (Geert Uytterhoeven, Grygorii Strashko).

   - Consolidation of device power management Kconfig options by making
     CONFIG_PM_SLEEP select CONFIG_PM_RUNTIME and removing the latter
     which is now redundant (Rafael J Wysocki and Kevin Hilman).  That
     is the first batch of the changes needed for this purpose.

   - Core device runtime power management support code cleanup related
     to the execution of callbacks (Andrzej Hajda).

   - cpuidle ARM support improvements (Lorenzo Pieralisi).

   - cpuidle cleanup related to the CPUIDLE_FLAG_TIME_VALID flag and a
     new MAINTAINERS entry for ARM Exynos cpuidle (Daniel Lezcano and
     Bartlomiej Zolnierkiewicz).

   - New cpufreq driver callback (->ready) to be executed when the
     cpufreq core is ready to use a given policy object and cpufreq-dt
     driver modification to use that callback for cooling device
     registration (Viresh Kumar).

   - cpufreq core fixes and cleanups (Viresh Kumar, Vince Hsu, James
     Geboski, Tomeu Vizoso).

   - Assorted fixes and cleanups in the cpufreq-pcc, intel_pstate,
     cpufreq-dt, pxa2xx cpufreq drivers (Lenny Szubowicz, Ethan Zhao,
     Stefan Wahren, Petr Cvek).

   - OPP (Operating Performance Points) framework modification to allow
     OPPs to be removed too and update of a few cpufreq drivers
     (cpufreq-dt, exynos5440, imx6q, cpufreq) to remove OPPs (added
     during initialization) on driver removal (Viresh Kumar).

   - Hibernation core fixes and cleanups (Tina Ruchandani and Markus
     Elfring).

   - PM Kconfig fix related to CPU power management (Pankaj Dubey).

   - cpupower tool fix (Prarit Bhargava)"

* tag 'pm+acpi-3.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (120 commits)
  i2c-omap / PM: Drop CONFIG_PM_RUNTIME from i2c-omap.c
  dmaengine / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  tools: cpupower: fix return checks for sysfs_get_idlestate_count()
  drivers: sh / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  e1000e / igb / PM: Eliminate CONFIG_PM_RUNTIME
  MMC / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  MFD / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  misc / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  media / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  input / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  leds: leds-gpio: Fix multiple instances registration without 'label' property
  iio / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  hsi / OMAP / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  i2c-hid / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  drm / exynos / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  gpio / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  hwrandom / exynos / PM: Use CONFIG_PM in #ifdef
  block / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  USB / PM: Drop CONFIG_PM_RUNTIME from the USB core
  PM: Merge the SET*_RUNTIME_PM_OPS() macros
  ...
2014-12-10 21:17:00 -08:00
Linus Torvalds
350e4f4985 This code is a fork from the trace-3.19 pull as it needed the trace_seq
clean ups from that branch.
 
 This code solves the issue of performing stack dumps from NMI context.
 The issue is that printk() is not safe from NMI context as if the NMI
 were to trigger when a printk() was being performed, the NMI could
 deadlock from the printk() internal locks. This has been seen in practice.
 
 With lots of review from Petr Mladek, this code went through several
 iterations, and we feel that it is now at a point of quality to be
 accepted into mainline.
 
 Here's what is contained in this patch set:
 
  o Creates a "seq_buf" generic buffer utility that allows a descriptor
    to be passed around where functions can write their own "printk()"
    formatted strings into it. The generic version was pulled out of
    the trace_seq() code that was made specifically for tracing.
 
  o The seq_buf code was change to model the seq_file code. I have
    a patch (not included for 3.19) that converts the seq_file.c code
    over to use seq_buf.c like the trace_seq.c code does. This was done
    to make sure that seq_buf.c is compatible with seq_file.c. I may
    try to get that patch in for 3.20.
 
  o The seq_buf.c file was moved to lib/ to remove it from being dependent
    on CONFIG_TRACING.
 
  o The printk() was updated to allow for a per_cpu "override" of
    the internal calls. That is, instead of writing to the console, a call
    to printk() may do something else. This made it easier to allow the
    NMI to change what printk() does in order to call dump_stack() without
    needing to update that code as well.
 
  o Finally, the dump_stack from all CPUs via NMI code was converted to
    use the seq_buf code. The caller to trigger the NMI code would wait
    till all the NMIs finished, and then it would print the seq_buf
    data to the console safely from a non NMI context.
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Merge tag 'trace-seq-buf-3.19' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull nmi-safe seq_buf printk update from Steven Rostedt:
 "This code is a fork from the trace-3.19 pull as it needed the
  trace_seq clean ups from that branch.

  This code solves the issue of performing stack dumps from NMI context.
  The issue is that printk() is not safe from NMI context as if the NMI
  were to trigger when a printk() was being performed, the NMI could
  deadlock from the printk() internal locks.  This has been seen in
  practice.

  With lots of review from Petr Mladek, this code went through several
  iterations, and we feel that it is now at a point of quality to be
  accepted into mainline.

  Here's what is contained in this patch set:

   - Creates a "seq_buf" generic buffer utility that allows a descriptor
     to be passed around where functions can write their own "printk()"
     formatted strings into it.  The generic version was pulled out of
     the trace_seq() code that was made specifically for tracing.

   - The seq_buf code was change to model the seq_file code.  I have a
     patch (not included for 3.19) that converts the seq_file.c code
     over to use seq_buf.c like the trace_seq.c code does.  This was
     done to make sure that seq_buf.c is compatible with seq_file.c.  I
     may try to get that patch in for 3.20.

   - The seq_buf.c file was moved to lib/ to remove it from being
     dependent on CONFIG_TRACING.

   - The printk() was updated to allow for a per_cpu "override" of the
     internal calls.  That is, instead of writing to the console, a call
     to printk() may do something else.  This made it easier to allow
     the NMI to change what printk() does in order to call dump_stack()
     without needing to update that code as well.

   - Finally, the dump_stack from all CPUs via NMI code was converted to
     use the seq_buf code.  The caller to trigger the NMI code would
     wait till all the NMIs finished, and then it would print the
     seq_buf data to the console safely from a non NMI context

  One added bonus is that this code also makes the NMI dump stack work
  on PREEMPT_RT kernels.  As printk() includes sleeping locks on
  PREEMPT_RT, printk() only writes to console if the console does not
  use any rt_mutex converted spin locks.  Which a lot do"

* tag 'trace-seq-buf-3.19' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  x86/nmi: Fix use of unallocated cpumask_var_t
  printk/percpu: Define printk_func when printk is not defined
  x86/nmi: Perform a safe NMI stack trace on all CPUs
  printk: Add per_cpu printk func to allow printk to be diverted
  seq_buf: Move the seq_buf code to lib/
  seq-buf: Make seq_buf_bprintf() conditional on CONFIG_BINARY_PRINTF
  tracing: Add seq_buf_get_buf() and seq_buf_commit() helper functions
  tracing: Have seq_buf use full buffer
  seq_buf: Add seq_buf_can_fit() helper function
  tracing: Add paranoid size check in trace_printk_seq()
  tracing: Use trace_seq_used() and seq_buf_used() instead of len
  tracing: Clean up tracing_fill_pipe_page()
  seq_buf: Create seq_buf_used() to find out how much was written
  tracing: Add a seq_buf_clear() helper and clear len and readpos in init
  tracing: Convert seq_buf fields to be like seq_file fields
  tracing: Convert seq_buf_path() to be like seq_path()
  tracing: Create seq_buf layer in trace_seq
2014-12-10 20:35:41 -08:00