Commit Graph

435 Commits

Author SHA1 Message Date
Linus Torvalds 271ecc5253 Merge branch 'akpm' (patches from Andrew)
Merge first patch-bomb from Andrew Morton:

 - some misc things

 - ofs2 updates

 - about half of MM

 - checkpatch updates

 - autofs4 update

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (120 commits)
  autofs4: fix string.h include in auto_dev-ioctl.h
  autofs4: use pr_xxx() macros directly for logging
  autofs4: change log print macros to not insert newline
  autofs4: make autofs log prints consistent
  autofs4: fix some white space errors
  autofs4: fix invalid ioctl return in autofs4_root_ioctl_unlocked()
  autofs4: fix coding style line length in autofs4_wait()
  autofs4: fix coding style problem in autofs4_get_set_timeout()
  autofs4: coding style fixes
  autofs: show pipe inode in mount options
  kallsyms: add support for relative offsets in kallsyms address table
  kallsyms: don't overload absolute symbol type for percpu symbols
  x86: kallsyms: disable absolute percpu symbols on !SMP
  checkpatch: fix another left brace warning
  checkpatch: improve UNSPECIFIED_INT test for bare signed/unsigned uses
  checkpatch: warn on bare unsigned or signed declarations without int
  checkpatch: exclude asm volatile from complex macro check
  mm: memcontrol: drop unnecessary lru locking from mem_cgroup_migrate()
  mm: migrate: consolidate mem_cgroup_migrate() calls
  mm/compaction: speed up pageblock_pfn_to_page() when zone is contiguous
  ...
2016-03-16 11:51:08 -07:00
Geliang Tang e6fd1fb3b5 init/main.c: use list_for_each_entry()
Use list_for_each_entry() instead of list_for_each() to simplify the code.

Signed-off-by: Geliang Tang <geliangtang@163.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15 16:55:16 -07:00
Linus Torvalds 710d60cbf1 Merge branch 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull cpu hotplug updates from Thomas Gleixner:
 "This is the first part of the ongoing cpu hotplug rework:

   - Initial implementation of the state machine

   - Runs all online and prepare down callbacks on the plugged cpu and
     not on some random processor

   - Replaces busy loop waiting with completions

   - Adds tracepoints so the states can be followed"

More detailed commentary on this work from an earlier email:
 "What's wrong with the current cpu hotplug infrastructure?

   - Asymmetry

     The hotplug notifier mechanism is asymmetric versus the bringup and
     teardown.  This is mostly caused by the notifier mechanism.

   - Largely undocumented dependencies

     While some notifiers use explicitely defined notifier priorities,
     we have quite some notifiers which use numerical priorities to
     express dependencies without any documentation why.

   - Control processor driven

     Most of the bringup/teardown of a cpu is driven by a control
     processor.  While it is understandable, that preperatory steps,
     like idle thread creation, memory allocation for and initialization
     of essential facilities needs to be done before a cpu can boot,
     there is no reason why everything else must run on a control
     processor.  Before this patch series, bringup looks like this:

       Control CPU                     Booting CPU

       do preparatory steps
       kick cpu into life

                                       do low level init

       sync with booting cpu           sync with control cpu

       bring the rest up

   - All or nothing approach

     There is no way to do partial bringups.  That's something which is
     really desired because we waste e.g.  at boot substantial amount of
     time just busy waiting that the cpu comes to life.  That's stupid
     as we could very well do preparatory steps and the initial IPI for
     other cpus and then go back and do the necessary low level
     synchronization with the freshly booted cpu.

   - Minimal debuggability

     Due to the notifier based design, it's impossible to switch between
     two stages of the bringup/teardown back and forth in order to test
     the correctness.  So in many hotplug notifiers the cancel
     mechanisms are either not existant or completely untested.

   - Notifier [un]registering is tedious

     To [un]register notifiers we need to protect against hotplug at
     every callsite.  There is no mechanism that bringup/teardown
     callbacks are issued on the online cpus, so every caller needs to
     do it itself.  That also includes error rollback.

  What's the new design?

     The base of the new design is a symmetric state machine, where both
     the control processor and the booting/dying cpu execute a well
     defined set of states.  Each state is symmetric in the end, except
     for some well defined exceptions, and the bringup/teardown can be
     stopped and reversed at almost all states.

     So the bringup of a cpu will look like this in the future:

       Control CPU                     Booting CPU

       do preparatory steps
       kick cpu into life

                                       do low level init

       sync with booting cpu           sync with control cpu

                                       bring itself up

     The synchronization step does not require the control cpu to wait.
     That mechanism can be done asynchronously via a worker or some
     other mechanism.

     The teardown can be made very similar, so that the dying cpu cleans
     up and brings itself down.  Cleanups which need to be done after
     the cpu is gone, can be scheduled asynchronously as well.

  There is a long way to this, as we need to refactor the notion when a
  cpu is available.  Today we set the cpu online right after it comes
  out of the low level bringup, which is not really correct.

  The proper mechanism is to set it to available, i.e. cpu local
  threads, like softirqd, hotplug thread etc. can be scheduled on that
  cpu, and once it finished all booting steps, it's set to online, so
  general workloads can be scheduled on it.  The reverse happens on
  teardown.  First thing to do is to forbid scheduling of general
  workloads, then teardown all the per cpu resources and finally shut it
  off completely.

  This patch series implements the basic infrastructure for this at the
  core level.  This includes the following:

   - Basic state machine implementation with well defined states, so
     ordering and prioritization can be expressed.

   - Interfaces to [un]register state callbacks

     This invokes the bringup/teardown callback on all online cpus with
     the proper protection in place and [un]installs the callbacks in
     the state machine array.

     For callbacks which have no particular ordering requirement we have
     a dynamic state space, so that drivers don't have to register an
     explicit hotplug state.

     If a callback fails, the code automatically does a rollback to the
     previous state.

   - Sysfs interface to drive the state machine to a particular step.

     This is only partially functional today.  Full functionality and
     therefor testability will be achieved once we converted all
     existing hotplug notifiers over to the new scheme.

   - Run all CPU_ONLINE/DOWN_PREPARE notifiers on the booting/dying
     processor:

       Control CPU                     Booting CPU

       do preparatory steps
       kick cpu into life

                                       do low level init

       sync with booting cpu           sync with control cpu
       wait for boot
                                       bring itself up

                                       Signal completion to control cpu

     In a previous step of this work we've done a full tree mechanical
     conversion of all hotplug notifiers to the new scheme.  The balance
     is a net removal of about 4000 lines of code.

     This is not included in this series, as we decided to take a
     different approach.  Instead of mechanically converting everything
     over, we will do a proper overhaul of the usage sites one by one so
     they nicely fit into the symmetric callback scheme.

     I decided to do that after I looked at the ugliness of some of the
     converted sites and figured out that their hotplug mechanism is
     completely buggered anyway.  So there is no point to do a
     mechanical conversion first as we need to go through the usage
     sites one by one again in order to achieve a full symmetric and
     testable behaviour"

* 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (23 commits)
  cpu/hotplug: Document states better
  cpu/hotplug: Fix smpboot thread ordering
  cpu/hotplug: Remove redundant state check
  cpu/hotplug: Plug death reporting race
  rcu: Make CPU_DYING_IDLE an explicit call
  cpu/hotplug: Make wait for dead cpu completion based
  cpu/hotplug: Let upcoming cpu bring itself fully up
  arch/hotplug: Call into idle with a proper state
  cpu/hotplug: Move online calls to hotplugged cpu
  cpu/hotplug: Create hotplug threads
  cpu/hotplug: Split out the state walk into functions
  cpu/hotplug: Unpark smpboot threads from the state machine
  cpu/hotplug: Move scheduler cpu_online notifier to hotplug core
  cpu/hotplug: Implement setup/removal interface
  cpu/hotplug: Make target state writeable
  cpu/hotplug: Add sysfs state interface
  cpu/hotplug: Hand in target state to _cpu_up/down
  cpu/hotplug: Convert the hotplugged cpu work to a state machine
  cpu/hotplug: Convert to a state machine for the control processor
  cpu/hotplug: Add tracepoints
  ...
2016-03-15 13:50:29 -07:00
Linus Torvalds d09e356ad0 Merge branch 'mm-readonly-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull read-only kernel memory updates from Ingo Molnar:
 "This tree adds two (security related) enhancements to the kernel's
  handling of read-only kernel memory:

   - extend read-only kernel memory to a new class of formerly writable
     kernel data: 'post-init read-only memory' via the __ro_after_init
     attribute, and mark the ARM and x86 vDSO as such read-only memory.

     This kind of attribute can be used for data that requires a once
     per bootup initialization sequence, but is otherwise never modified
     after that point.

     This feature was based on the work by PaX Team and Brad Spengler.

     (by Kees Cook, the ARM vDSO bits by David Brown.)

   - make CONFIG_DEBUG_RODATA always enabled on x86 and remove the
     Kconfig option.  This simplifies the kernel and also signals that
     read-only memory is the default model and a first-class citizen.
     (Kees Cook)"

* 'mm-readonly-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  ARM/vdso: Mark the vDSO code read-only after init
  x86/vdso: Mark the vDSO code read-only after init
  lkdtm: Verify that '__ro_after_init' works correctly
  arch: Introduce post-init read-only memory
  x86/mm: Always enable CONFIG_DEBUG_RODATA and remove the Kconfig option
  mm/init: Add 'rodata=off' boot cmdline parameter to disable read-only kernel mappings
  asm-generic: Consolidate mark_rodata_ro()
2016-03-14 16:58:50 -07:00
Thomas Gleixner 931ef16330 cpu/hotplug: Unpark smpboot threads from the state machine
Handle the smpboot threads in the state machine.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-arch@vger.kernel.org
Cc: Rik van Riel <riel@redhat.com>
Cc: Rafael Wysocki <rafael.j.wysocki@intel.com>
Cc: "Srivatsa S. Bhat" <srivatsa@mit.edu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Paul McKenney <paulmck@linux.vnet.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul Turner <pjt@google.com>
Link: http://lkml.kernel.org/r/20160226182341.295777684@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-03-01 20:36:56 +01:00
Thomas Gleixner cff7d378d3 cpu/hotplug: Convert to a state machine for the control processor
Move the split out steps into a callback array and let the cpu_up/down
code iterate through the array functions. For now most of the
callbacks are asymmetric to resemble the current hotplug maze.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-arch@vger.kernel.org
Cc: Rik van Riel <riel@redhat.com>
Cc: Rafael Wysocki <rafael.j.wysocki@intel.com>
Cc: "Srivatsa S. Bhat" <srivatsa@mit.edu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Paul McKenney <paulmck@linux.vnet.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul Turner <pjt@google.com>
Link: http://lkml.kernel.org/r/20160226182340.671816690@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-03-01 20:36:54 +01:00
Kees Cook d2aa1acad2 mm/init: Add 'rodata=off' boot cmdline parameter to disable read-only kernel mappings
It may be useful to debug writes to the readonly sections of memory,
so provide a cmdline "rodata=off" to allow for this. This can be
expanded in the future to support "log" and "write" modes, but that
will need to be architecture-specific.

This also makes KDB software breakpoints more usable, as read-only
mappings can now be disabled on any kernel.

Suggested-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: David Brown <david.brown@linaro.org>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Emese Revfy <re.emese@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mathias Krause <minipli@googlemail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: PaX Team <pageexec@freemail.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: kernel-hardening@lists.openwall.com
Cc: linux-arch <linux-arch@vger.kernel.org>
Link: http://lkml.kernel.org/r/1455748879-21872-3-git-send-email-keescook@chromium.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-22 08:51:37 +01:00
Andrey Ryabinin 06bea3dbfe locking/lockdep: Eliminate lockdep_init()
Lockdep is initialized at compile time now.  Get rid of lockdep_init().

Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Krinkin <krinkin.m.u@gmail.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Cc: mm-commits@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-09 12:03:25 +01:00
Yaowei Bai 31c025b5fe init/main.c: obsolete_checksetup can be boolean
Make obsolete_checksetup() return bool due to this particular function
only using either one or zero as its return value.

No functional change.

Signed-off-by: Yaowei Bai <baiyaowei@cmss.chinamobile.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-20 17:09:18 -08:00
Paul E. McKenney 967dcb8fe6 rcu: Wire up rcu_end_inkernel_boot()
This commit adds the invocation of rcu_end_inkernel_boot() just before
init is invoked.  This allows the CONFIG_RCU_EXPEDITE_BOOT Kconfig
option to do something useful and prepares for the upcoming
rcupdate.rcu_normal_after_boot kernel parameter.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2015-12-04 12:26:54 -08:00
Frederic Weisbecker 90f023030e kmod: use system_unbound_wq instead of khelper
We need to launch the usermodehelper kernel threads with the widest
affinity and this is partly why we use khelper.  This workqueue has
unbound properties and thus a wide affinity inherited by all its children.

Now khelper also has special properties that we aren't much interested in:
ordered and singlethread.  There is really no need about ordering as all
we do is creating kernel threads.  This can be done concurrently.  And
singlethread is a useless limitation as well.

The workqueue engine already proposes generic unbound workqueues that
don't share these useless properties and handle well parallel jobs.

The only worrysome specific is their affinity to the node of the current
CPU.  It's fine for creating the usermodehelper kernel threads but those
inherit this affinity for longer jobs such as requesting modules.

This patch proposes to use these node affine unbound workqueues assuming
that a node is sufficient to handle several parallel usermodehelper
requests.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Rik van Riel <riel@redhat.com>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-10 13:29:01 -07:00
Mel Gorman 4248b0da46 fs, file table: reinit files_stat.max_files after deferred memory initialisation
Dave Hansen reported the following;

	My laptop has been behaving strangely with 4.2-rc2.  Once I log
	in to my X session, I start getting all kinds of strange errors
	from applications and see this in my dmesg:

        	VFS: file-max limit 8192 reached

The problem is that the file-max is calculated before memory is fully
initialised and miscalculates how much memory the kernel is using.  This
patch recalculates file-max after deferred memory initialisation.  Note
that using memory hotplug infrastructure would not have avoided this
problem as the value is not recalculated after memory hot-add.

4.1:             files_stat.max_files = 6582781
4.2-rc2:         files_stat.max_files = 8192
4.2-rc2 patched: files_stat.max_files = 6562467

Small differences with the patch applied and 4.1 but not enough to matter.

Signed-off-by: Mel Gorman <mgorman@suse.de>
Reported-by: Dave Hansen <dave.hansen@intel.com>
Cc: Nicolai Stange <nicstange@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Alex Ng <alexng@microsoft.com>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-08-07 04:39:40 +03:00
Mel Gorman 0e1cc95b4c mm: meminit: finish initialisation of struct pages before basic setup
Waiman Long reported that 24TB machines hit OOM during basic setup when
struct page initialisation was deferred.  One approach is to initialise
memory on demand but it interferes with page allocator paths.  This patch
creates dedicated threads to initialise memory before basic setup.  It
then blocks on a rw_semaphore until completion as a wait_queue and counter
is overkill.  This may be slower to boot but it's simplier overall and
also gets rid of a section mangling which existed so kswapd could do the
initialisation.

[akpm@linux-foundation.org: include rwsem.h, use DECLARE_RWSEM, fix comment, remove unneeded cast]
Signed-off-by: Mel Gorman <mgorman@suse.de>
Cc: Waiman Long <waiman.long@hp.com
Cc: Nathan Zimmer <nzimmer@sgi.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Scott Norton <scott.norton@hp.com>
Tested-by: Daniel J Blueman <daniel@numascale.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-06-30 19:44:56 -07:00
Linus Torvalds 8d7804a2f0 Driver core patches for 4.2-rc1
Here is the driver core / firmware changes for 4.2-rc1.
 
 A number of small changes all over the place in the driver core, and in
 the firmware subsystem.  Nothing really major, full details in the
 shortlog.  Some of it is a bit of churn, given that the platform driver
 probing changes was found to not work well, so they were reverted.
 
 All of these have been in linux-next for a while with no reported
 issues.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'driver-core-4.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core updates from Greg KH:
 "Here is the driver core / firmware changes for 4.2-rc1.

  A number of small changes all over the place in the driver core, and
  in the firmware subsystem.  Nothing really major, full details in the
  shortlog.  Some of it is a bit of churn, given that the platform
  driver probing changes was found to not work well, so they were
  reverted.

  All of these have been in linux-next for a while with no reported
  issues"

* tag 'driver-core-4.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (31 commits)
  Revert "base/platform: Only insert MEM and IO resources"
  Revert "base/platform: Continue on insert_resource() error"
  Revert "of/platform: Use platform_device interface"
  Revert "base/platform: Remove code duplication"
  firmware: add missing kfree for work on async call
  fs: sysfs: don't pass count == 0 to bin file readers
  base:dd - Fix for typo in comment to function driver_deferred_probe_trigger().
  base/platform: Remove code duplication
  of/platform: Use platform_device interface
  base/platform: Continue on insert_resource() error
  base/platform: Only insert MEM and IO resources
  firmware: use const for remaining firmware names
  firmware: fix possible use after free on name on asynchronous request
  firmware: check for file truncation on direct firmware loading
  firmware: fix __getname() missing failure check
  drivers: of/base: move of_init to driver_init
  drivers/base: cacheinfo: fix annoying typo when DT nodes are absent
  sysfs: disambiguate between "error code" and "failure" in comments
  driver-core: fix build for !CONFIG_MODULES
  driver-core: make __device_attach() static
  ...
2015-06-26 15:07:37 -07:00
Rafael J. Wysocki b064a8fa77 ACPI / init: Switch over platform to the ACPI mode later
Commit 73f7d1ca32 "ACPI / init: Run acpi_early_init() before
timekeeping_init()" moved the ACPI subsystem initialization,
including the ACPI mode enabling, to an earlier point in the
initialization sequence, to allow the timekeeping subsystem
use ACPI early.  Unfortunately, that resulted in boot regressions
on some systems and the early ACPI initialization was moved toward
its original position in the kernel initialization code by commit
c4e1acbb35 "ACPI / init: Invoke early ACPI initialization later".

However, that turns out to be insufficient, as boot is still broken
on the Tyan S8812 mainboard.

To fix that issue, split the ACPI early initialization code into
two pieces so the majority of it still located in acpi_early_init()
and the part switching over the platform into the ACPI mode goes into
a new function, acpi_subsystem_init(), executed at the original early
ACPI initialization spot.

That fixes the Tyan S8812 boot problem, but still allows ACPI
tables to be loaded earlier which is useful to the EFI code in
efi_enter_virtual_mode().

Link: https://bugzilla.kernel.org/show_bug.cgi?id=97141
Fixes: 73f7d1ca32 "ACPI / init: Run acpi_early_init() before timekeeping_init()"
Reported-and-tested-by: Marius Tolzmann <tolzmann@molgen.mpg.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Toshi Kani <toshi.kani@hp.com>
Reviewed-by: Hanjun Guo <hanjun.guo@linaro.org>
Reviewed-by: Lee, Chun-Yi <jlee@suse.com>
2015-06-10 23:51:27 +02:00
Luis R. Rodriguez ecc8617053 module: add extra argument for parse_params() callback
This adds an extra argument onto parse_params() to be used
as a way to make the unused callback a bit more useful and
generic by allowing the caller to pass on a data structure
of its choice. An example use case is to allow us to easily
make module parameters for every module which we will do
next.

@ parse @
identifier name, args, params, num, level_min, level_max;
identifier unknown, param, val, doing;
type s16;
@@
 extern char *parse_args(const char *name,
 			 char *args,
 			 const struct kernel_param *params,
 			 unsigned num,
 			 s16 level_min,
 			 s16 level_max,
+			 void *arg,
 			 int (*unknown)(char *param, char *val,
					const char *doing
+					, void *arg
					));

@ parse_mod @
identifier name, args, params, num, level_min, level_max;
identifier unknown, param, val, doing;
type s16;
@@
 char *parse_args(const char *name,
 			 char *args,
 			 const struct kernel_param *params,
 			 unsigned num,
 			 s16 level_min,
 			 s16 level_max,
+			 void *arg,
 			 int (*unknown)(char *param, char *val,
					const char *doing
+					, void *arg
					))
{
	...
}

@ parse_args_found @
expression R, E1, E2, E3, E4, E5, E6;
identifier func;
@@

(
	R =
	parse_args(E1, E2, E3, E4, E5, E6,
+		   NULL,
		   func);
|
	R =
	parse_args(E1, E2, E3, E4, E5, E6,
+		   NULL,
		   &func);
|
	R =
	parse_args(E1, E2, E3, E4, E5, E6,
+		   NULL,
		   NULL);
|
	parse_args(E1, E2, E3, E4, E5, E6,
+		   NULL,
		   func);
|
	parse_args(E1, E2, E3, E4, E5, E6,
+		   NULL,
		   &func);
|
	parse_args(E1, E2, E3, E4, E5, E6,
+		   NULL,
		   NULL);
)

@ parse_args_unused depends on parse_args_found @
identifier parse_args_found.func;
@@

int func(char *param, char *val, const char *unused
+		 , void *arg
		 )
{
	...
}

@ mod_unused depends on parse_args_found @
identifier parse_args_found.func;
expression A1, A2, A3;
@@

-	func(A1, A2, A3);
+	func(A1, A2, A3, NULL);

Generated-by: Coccinelle SmPL
Cc: cocci@systeme.lip6.fr
Cc: Tejun Heo <tj@kernel.org>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Felipe Contreras <felipe.contreras@gmail.com>
Cc: Ewan Milne <emilne@redhat.com>
Cc: Jean Delvare <jdelvare@suse.de>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: linux-kernel@vger.kernel.org
Reviewed-by: Tejun Heo <tj@kernel.org>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Luis R. Rodriguez <mcgrof@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-20 00:25:24 -07:00
Heinrich Schuchardt ff691f6e03 kernel/fork.c: new function for max_threads
PAGE_SIZE is not guaranteed to be equal to or less than 8 times the
THREAD_SIZE.

E.g.  architecture hexagon may have page size 1M and thread size 4096.
This would lead to a division by zero in the calculation of max_threads.

With this patch the buggy code is moved to a separate function
set_max_threads.  The error is not fixed.

After fixing the problem in a separate patch the new function can be
reused to adjust max_threads after adding or removing memory.

Argument mempages of function fork_init() is removed as totalram_pages is
an exported symbol.

The creation of separate patches for refactoring to a new function and for
fixing the logic was suggested by Ingo Molnar.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-17 09:04:06 -04:00
Linus Torvalds 1dcf58d6e6 Merge branch 'akpm' (patches from Andrew)
Merge first patchbomb from Andrew Morton:

 - arch/sh updates

 - ocfs2 updates

 - kernel/watchdog feature

 - about half of mm/

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (122 commits)
  Documentation: update arch list in the 'memtest' entry
  Kconfig: memtest: update number of test patterns up to 17
  arm: add support for memtest
  arm64: add support for memtest
  memtest: use phys_addr_t for physical addresses
  mm: move memtest under mm
  mm, hugetlb: abort __get_user_pages if current has been oom killed
  mm, mempool: do not allow atomic resizing
  memcg: print cgroup information when system panics due to panic_on_oom
  mm: numa: remove migrate_ratelimited
  mm: fold arch_randomize_brk into ARCH_HAS_ELF_RANDOMIZE
  mm: split ET_DYN ASLR from mmap ASLR
  s390: redefine randomize_et_dyn for ELF_ET_DYN_BASE
  mm: expose arch_mmap_rnd when available
  s390: standardize mmap_rnd() usage
  powerpc: standardize mmap_rnd() usage
  mips: extract logic for mmap_rnd()
  arm64: standardize mmap_rnd() usage
  x86: standardize mmap_rnd() usage
  arm: factor out mmap ASLR into mmap_rnd
  ...
2015-04-14 16:49:17 -07:00
Toshi Kani 0ddab1d2ed lib/ioremap.c: add huge I/O map capability interfaces
Add ioremap_pud_enabled() and ioremap_pmd_enabled(), which return 1 when
I/O mappings with pud/pmd are enabled on the kernel.

ioremap_huge_init() calls arch_ioremap_pud_supported() and
arch_ioremap_pmd_supported() to initialize the capabilities at boot-time.

A new kernel option "nohugeiomap" is also added, so that user can disable
the huge I/O map capabilities when necessary.

Signed-off-by: Toshi Kani <toshi.kani@hp.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Robert Elliott <Elliott@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-14 16:49:04 -07:00
Linus Torvalds 078838d565 Merge branch 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull RCU changes from Ingo Molnar:
 "The main changes in this cycle were:

   - changes permitting use of call_rcu() and friends very early in
     boot, for example, before rcu_init() is invoked.

   - add in-kernel API to enable and disable expediting of normal RCU
     grace periods.

   - improve RCU's handling of (hotplug-) outgoing CPUs.

   - NO_HZ_FULL_SYSIDLE fixes.

   - tiny-RCU updates to make it more tiny.

   - documentation updates.

   - miscellaneous fixes"

* 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (58 commits)
  cpu: Provide smpboot_thread_init() on !CONFIG_SMP kernels as well
  cpu: Defer smpboot kthread unparking until CPU known to scheduler
  rcu: Associate quiescent-state reports with grace period
  rcu: Yet another fix for preemption and CPU hotplug
  rcu: Add diagnostics to grace-period cleanup
  rcutorture: Default to grace-period-initialization delays
  rcu: Handle outgoing CPUs on exit from idle loop
  cpu: Make CPU-offline idle-loop transition point more precise
  rcu: Eliminate ->onoff_mutex from rcu_node structure
  rcu: Process offlining and onlining only at grace-period start
  rcu: Move rcu_report_unblock_qs_rnp() to common code
  rcu: Rework preemptible expedited bitmask handling
  rcu: Remove event tracing from rcu_cpu_notify(), used by offline CPUs
  rcutorture: Enable slow grace-period initializations
  rcu: Provide diagnostic option to slow down grace-period initialization
  rcu: Detect stalls caused by failure to propagate up rcu_node tree
  rcu: Eliminate empty HOTPLUG_CPU ifdef
  rcu: Simplify sync_rcu_preempt_exp_init()
  rcu: Put all orphan-callback-related code under same comment
  rcu: Consolidate offline-CPU callback initialization
  ...
2015-04-14 13:36:04 -07:00
Linus Torvalds d0bbe0dd35 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial
Pull trivial tree from Jiri Kosina:
 "Usual trivial tree updates.  Nothing outstanding -- mostly printk()
  and comment fixes and unused identifier removals"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial:
  goldfish: goldfish_tty_probe() is not using 'i' any more
  powerpc: Fix comment in smu.h
  qla2xxx: Fix printks in ql_log message
  lib: correct link to the original source for div64_u64
  si2168, tda10071, m88ds3103: Fix firmware wording
  usb: storage: Fix printk in isd200_log_config()
  qla2xxx: Fix printk in qla25xx_setup_mode
  init/main: fix reset_device comment
  ipwireless: missing assignment
  goldfish: remove unreachable line of code
  coredump: Fix do_coredump() comment
  stacktrace.h: remove duplicate declaration task_struct
  smpboot.h: Remove unused function prototype
  treewide: Fix typo in printk messages
  treewide: Fix typo in printk messages
  mod_devicetable: fix comment for match_flags
2015-04-14 09:50:27 -07:00
Paul E. McKenney 00df35f991 cpu: Defer smpboot kthread unparking until CPU known to scheduler
Currently, smpboot_unpark_threads() is invoked before the incoming CPU
has been added to the scheduler's runqueue structures.  This might
potentially cause the unparked kthread to run on the wrong CPU, since the
correct CPU isn't fully set up yet.

That causes a sporadic, hard to debug boot crash triggering on some
systems, reported by Borislav Petkov, and bisected down to:

  2a442c9c64 ("x86: Use common outgoing-CPU-notification code")

This patch places smpboot_unpark_threads() in a CPU hotplug
notifier with priority set so that these kthreads are unparked just after
the CPU has been added to the runqueues.

Reported-and-tested-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-04-13 08:25:16 +02:00
Frans Klaver fc454fdc10 init/main: fix reset_device comment
Fix incorrect spelling of situation.

Signed-off-by: Frans Klaver <fransklaver@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2015-03-06 23:12:43 +01:00
Zefan Li 695df2132c cpuset: initialize cpuset a bit early
Now we call ss->bind() in cgroup_init(), so cgroup_init() will
call cpuset_bind() and then the latter will access top_cpuset's
cpumask, which is NULL, because cpuset_init() is called after
cgroup_init()

The simplest fix is to swap cgroup_init() and cpuset_init().

Cc: Vladimir Davydov <vdavydov@parallels.com>
Fixes: 295458e672 ("cgroup: call cgroup_subsys->bind on cgroup subsys initialization")
Reported by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: Zefan Li <lizefan@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Vladimir Davydov <vdavydov@parallels.com>
2015-03-05 08:05:20 -05:00
Andy Lutomirski 5125991c9a init: remove CONFIG_INIT_FALLBACK
CONFIG_INIT_FALLBACK adds config bloat without an obvious use case that
makes it worth keeping around.  Delete it.

Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Chuck Ebbert <cebbert.lkml@gmail.com>
Cc: Frank Rowand <frowand.list@gmail.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Rob Landley <rob@landley.net>
Cc: Shuah Khan <shuah.kh@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-13 21:21:42 -08:00
Thomas Gleixner 30b8b0066c init: Get rid of x86isms
The UP local API support can be set up from an early initcall. No need
for horrible hackery in the init code.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Link: http://lkml.kernel.org/r/20150115211703.827943883@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-01-22 15:10:56 +01:00
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
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 67e2c38838 Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security
Pull security layer updates from James Morris:
 "In terms of changes, there's general maintenance to the Smack,
  SELinux, and integrity code.

  The IMA code adds a new kconfig option, IMA_APPRAISE_SIGNED_INIT,
  which allows IMA appraisal to require signatures.  Support for reading
  keys from rootfs before init is call is also added"

* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (23 commits)
  selinux: Remove security_ops extern
  security: smack: fix out-of-bounds access in smk_parse_smack()
  VFS: refactor vfs_read()
  ima: require signature based appraisal
  integrity: provide a hook to load keys when rootfs is ready
  ima: load x509 certificate from the kernel
  integrity: provide a function to load x509 certificate from the kernel
  integrity: define a new function integrity_read_file()
  Security: smack: replace kzalloc with kmem_cache for inode_smack
  Smack: Lock mode for the floor and hat labels
  ima: added support for new kernel cmdline parameter ima_template_fmt
  ima: allocate field pointers array on demand in template_desc_init_fields()
  ima: don't allocate a copy of template_fmt in template_desc_init_fields()
  ima: display template format in meas. list if template name length is zero
  ima: added error messages to template-related functions
  ima: use atomic bit operations to protect policy update interface
  ima: ignore empty and with whitespaces policy lines
  ima: no need to allocate entry for comment
  ima: report policy load status
  ima: use path names cache
  ...
2014-12-14 20:36:37 -08:00
Joonsoo Kim eefa864b70 mm/page_ext: resurrect struct page extending code for debugging
When we debug something, we'd like to insert some information to every
page.  For this purpose, we sometimes modify struct page itself.  But,
this has drawbacks.  First, it requires re-compile.  This makes us
hesitate to use the powerful debug feature so development process is
slowed down.  And, second, sometimes it is impossible to rebuild the
kernel due to third party module dependency.  At third, system behaviour
would be largely different after re-compile, because it changes size of
struct page greatly and this structure is accessed by every part of
kernel.  Keeping this as it is would be better to reproduce errornous
situation.

This feature is intended to overcome above mentioned problems.  This
feature allocates memory for extended data per page in certain place
rather than the struct page itself.  This memory can be accessed by the
accessor functions provided by this code.  During the boot process, it
checks whether allocation of huge chunk of memory is needed or not.  If
not, it avoids allocating memory at all.  With this advantage, we can
include this feature into the kernel in default and can avoid rebuild and
solve related problems.

Until now, memcg uses this technique.  But, now, memcg decides to embed
their variable to struct page itself and it's code to extend struct page
has been removed.  I'd like to use this code to develop debug feature, so
this patch resurrect it.

To help these things to work well, this patch introduces two callbacks for
clients.  One is the need callback which is mandatory if user wants to
avoid useless memory allocation at boot-time.  The other is optional, init
callback, which is used to do proper initialization after memory is
allocated.  Detailed explanation about purpose of these functions is in
code comment.  Please refer it.

Others are completely same with previous extension code in memcg.

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
Al Viro 707c5960f1 Merge branch 'nsfs' into for-next 2014-12-10 21:31:59 -05:00
Al Viro e149ed2b80 take the targets of /proc/*/ns/* symlinks to separate fs
New pseudo-filesystem: nsfs.  Targets of /proc/*/ns/* live there now.
It's not mountable (not even registered, so it's not in /proc/filesystems,
etc.).  Files on it *are* bindable - we explicitly permit that in do_loopback().

This stuff lives in fs/nsfs.c now; proc_ns_fget() moved there as well.
get_proc_ns() is a macro now (it's simply returning ->i_private; would
have been an inline, if not for header ordering headache).
proc_ns_inode() is an ex-parrot.  The interface used in procfs is
ns_get_path(path, task, ops) and ns_get_name(buf, size, task, ops).

Dentries and inodes are never hashed; a non-counting reference to dentry
is stashed in ns_common (removed by ->d_prune()) and reused by ns_get_path()
if present.  See ns_get_path()/ns_prune_dentry/nsfs_evict() for details
of that mechanism.

As the result, proc_ns_follow_link() has stopped poking in nd->path.mnt;
it does nd_jump_link() on a consistent <vfsmount,dentry> pair it gets
from ns_get_path().

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-12-10 21:30:20 -05:00
Andy Lutomirski 6ef4536e2f init: allow CONFIG_INIT_FALLBACK=n to disable defaults if init= fails
If a user puts init=/whatever on the command line and /whatever can't be
run, then the kernel will try a few default options before giving up.  If
init=/whatever came from a bootloader prompt, then this is unexpected but
probably harmless.  On the other hand, if it comes from a script (e.g.  a
tool like virtme or perhaps a future kselftest script), then the fallbacks
are likely to exist, but they'll do the wrong thing.  For example, they
might unexpectedly invoke systemd.

This adds a config option CONFIG_INIT_FALLBACK.  If unset, then a failure
to run the specified init= process be fatal.

The tentative plan is to remove CONFIG_INIT_FALLBACK for 3.20.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Cc: Rob Landley <rob@landley.net>
Cc: Chuck Ebbert <cebbert.lkml@gmail.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Shuah Khan <shuah.kh@samsung.com>
Cc: Frank Rowand <frowand.list@gmail.com>
Cc: Josh Triplett <josh@joshtriplett.org>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-10 17:41:12 -08:00
Johannes Weiner 1306a85aed mm: embed the memcg pointer directly into struct page
Memory cgroups used to have 5 per-page pointers.  To allow users to
disable that amount of overhead during runtime, those pointers were
allocated in a separate array, with a translation layer between them and
struct page.

There is now only one page pointer remaining: the memcg pointer, that
indicates which cgroup the page is associated with when charged.  The
complexity of runtime allocation and the runtime translation overhead is
no longer justified to save that *potential* 0.19% of memory.  With
CONFIG_SLUB, page->mem_cgroup actually sits in the doubleword padding
after the page->private member and doesn't even increase struct page,
and then this patch actually saves space.  Remaining users that care can
still compile their kernels without CONFIG_MEMCG.

     text    data     bss     dec     hex     filename
  8828345 1725264  983040 11536649 b00909  vmlinux.old
  8827425 1725264  966656 11519345 afc571  vmlinux.new

[mhocko@suse.cz: update Documentation/cgroups/memory.txt]
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.cz>
Acked-by: Vladimir Davydov <vdavydov@parallels.com>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Vladimir Davydov <vdavydov@parallels.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: Konstantin Khlebnikov <koct9i@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-10 17:41:09 -08:00
James Morris a6aacbde40 Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity into next 2014-11-19 21:36:07 +11:00
Dmitry Kasatkin c9cd2ce2bc integrity: provide a hook to load keys when rootfs is ready
Keys can only be loaded once the rootfs is mounted. Initcalls
are not suitable for that. This patch defines a special hook
to load the x509 public keys onto the IMA keyring, before
attempting to access any file. The keys are required for
verifying the file's signature. The hook is called after the
root filesystem is mounted and before the kernel calls 'init'.

Changes in v3:
* added more explanation to the patch description (Mimi)

Changes in v2:
* Hook renamed as 'integrity_load_keys()' to handle both IMA and EVM
  keys by integrity subsystem.
* Hook patch moved after defining loading functions

Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-11-17 23:12:01 -05:00
Daniel Thompson 3438cf549d param: fix crash on bad kernel arguments
Currently if the user passes an invalid value on the kernel command line
then the kernel will crash during argument parsing. On most systems this
is very hard to debug because the console hasn't been initialized yet.

This is a regression due to commit 51e158c12a ("param: hand arguments
after -- straight to init") which, in response to the systemd debug
controversy, made it possible to explicitly pass arguments to init. To
achieve this parse_args() was extended from simply returning an error
code to returning a pointer. Regretably the new init args logic does not
perform a proper validity check on the pointer resulting in a crash.

This patch fixes the validity check. Should the check fail then no arguments
will be passed to init. This is reasonable and matches how the kernel treats
its own arguments (i.e. no error recovery).

Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
Cc: stable@vger.kernel.org
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2014-11-11 17:03:19 +10:30
Geert Uytterhoeven 63a12d9d01 kernel/param: consolidate __{start,stop}___param[] in <linux/moduleparam.h>
Consolidate the various external const and non-const declarations of
__start___param[] and __stop___param in <linux/moduleparam.h>.  This
requires making a few struct kernel_param pointers in kernel/params.c
const.

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-14 02:18:28 +02:00
Linus Torvalds faafcba3b5 Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler updates from Ingo Molnar:
 "The main changes in this cycle were:

   - Optimized support for Intel "Cluster-on-Die" (CoD) topologies (Dave
     Hansen)

   - Various sched/idle refinements for better idle handling (Nicolas
     Pitre, Daniel Lezcano, Chuansheng Liu, Vincent Guittot)

   - sched/numa updates and optimizations (Rik van Riel)

   - sysbench speedup (Vincent Guittot)

   - capacity calculation cleanups/refactoring (Vincent Guittot)

   - Various cleanups to thread group iteration (Oleg Nesterov)

   - Double-rq-lock removal optimization and various refactorings
     (Kirill Tkhai)

   - various sched/deadline fixes

  ... and lots of other changes"

* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (72 commits)
  sched/dl: Use dl_bw_of() under rcu_read_lock_sched()
  sched/fair: Delete resched_cpu() from idle_balance()
  sched, time: Fix build error with 64 bit cputime_t on 32 bit systems
  sched: Improve sysbench performance by fixing spurious active migration
  sched/x86: Fix up typo in topology detection
  x86, sched: Add new topology for multi-NUMA-node CPUs
  sched/rt: Use resched_curr() in task_tick_rt()
  sched: Use rq->rd in sched_setaffinity() under RCU read lock
  sched: cleanup: Rename 'out_unlock' to 'out_free_new_mask'
  sched: Use dl_bw_of() under RCU read lock
  sched/fair: Remove duplicate code from can_migrate_task()
  sched, mips, ia64: Remove __ARCH_WANT_UNLOCKED_CTXSW
  sched: print_rq(): Don't use tasklist_lock
  sched: normalize_rt_tasks(): Don't use _irqsave for tasklist_lock, use task_rq_lock()
  sched: Fix the task-group check in tg_has_rt_tasks()
  sched/fair: Leverage the idle state info when choosing the "idlest" cpu
  sched: Let the scheduler see CPU idle states
  sched/deadline: Fix inter- exclusive cpusets migrations
  sched/deadline: Clear dl_entity params when setscheduling to different class
  sched/numa: Kill the wrong/dead TASK_DEAD check in task_numa_fault()
  ...
2014-10-13 16:23:15 +02:00
Linus Torvalds d6dd50e07c Merge branch 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull RCU updates from Ingo Molnar:
 "The main changes in this cycle were:

   - changes related to No-CBs CPUs and NO_HZ_FULL

   - RCU-tasks implementation

   - torture-test updates

   - miscellaneous fixes

   - locktorture updates

   - RCU documentation updates"

* 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (81 commits)
  workqueue: Use cond_resched_rcu_qs macro
  workqueue: Add quiescent state between work items
  locktorture: Cleanup header usage
  locktorture: Cannot hold read and write lock
  locktorture: Fix __acquire annotation for spinlock irq
  locktorture: Support rwlocks
  rcu: Eliminate deadlock between CPU hotplug and expedited grace periods
  locktorture: Document boot/module parameters
  rcutorture: Rename rcutorture_runnable parameter
  locktorture: Add test scenario for rwsem_lock
  locktorture: Add test scenario for mutex_lock
  locktorture: Make torture scripting account for new _runnable name
  locktorture: Introduce torture context
  locktorture: Support rwsems
  locktorture: Add infrastructure for torturing read locks
  torture: Address race in module cleanup
  locktorture: Make statistics generic
  locktorture: Teach about lock debugging
  locktorture: Support mutexes
  locktorture: Add documentation
  ...
2014-10-13 15:44:12 +02:00
Aaron Tomlin d4311ff1a8 init/main.c: Give init_task a canary
Tasks get their end of stack set to STACK_END_MAGIC with the
aim to catch stack overruns. Currently this feature does not
apply to init_task. This patch removes this restriction.

Note that a similar patch was posted by Prarit Bhargava
some time ago but was never merged:

  http://marc.info/?l=linux-kernel&m=127144305403241&w=2

Signed-off-by: Aaron Tomlin <atomlin@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Cc: aneesh.kumar@linux.vnet.ibm.com
Cc: dzickus@redhat.com
Cc: bmr@redhat.com
Cc: jcastillo@redhat.com
Cc: jgh@redhat.com
Cc: minchan@kernel.org
Cc: tglx@linutronix.de
Cc: hannes@cmpxchg.org
Cc: Alex Thorlton <athorlton@sgi.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Daeseok Youn <daeseok.youn@gmail.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Fabian Frederick <fabf@skynet.be>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Michael Opdenacker <michael.opdenacker@free-electrons.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Seiji Aguchi <seiji.aguchi@hds.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Vladimir Davydov <vdavydov@parallels.com>
Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Cc: linuxppc-dev@lists.ozlabs.org
Link: http://lkml.kernel.org/r/1410527779-8133-2-git-send-email-atomlin@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-09-19 12:35:22 +02:00
Paul E. McKenney f4579fc57c rcu: Fix attempt to avoid unsolicited offloading of callbacks
Commit b58cc46c5f (rcu: Don't offload callbacks unless specifically
requested) failed to adjust the callback lists of the CPUs that are
known to be no-CBs CPUs only because they are also nohz_full= CPUs.
This failure can result in callbacks that are posted during early boot
getting stranded on nxtlist for CPUs whose no-CBs property becomes
apparent late, and there can also be spurious warnings about offline
CPUs posting callbacks.

This commit fixes these problems by adding an early-boot rcu_init_nohz()
that properly initializes the no-CBs CPUs.

Note that kernels built with CONFIG_RCU_NOCB_CPU_ALL=y or with
CONFIG_RCU_NOCB_CPU=n do not exhibit this bug.  Neither do kernels
booted without the nohz_full= boot parameter.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Pranith Kumar <bobby.prani@gmail.com>
Tested-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2014-09-16 10:07:59 -07:00
Frederic Weisbecker a80e49e2cc nohz: Move nohz full init call to tick init
This way we unbloat a bit main.c and more importantly we initialize
nohz full after init_IRQ(). This dependency will be needed in further
patches because nohz full needs irq work to raise its own IRQ.
Information about the support for this ability on ARM64 is obtained on
init_IRQ() which initialize the pointer to __smp_call_function.

Since tick_init() is called right after init_IRQ(), this is a good place
to call tick_nohz_init() and prepare for that dependency.

Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2014-09-13 18:34:44 +02:00
Fabian Frederick dd4d9fecbe init/main.c: code clean-up
Fixing some checkpatch warnings(remove global initialization, move
__initdata, coalesce formats ...)

Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-08 15:57:27 -07:00
Linus Torvalds 4251c2a670 Most of this is cleaning up various driver sysfs permissions so we can
re-add the perm check (we unified the module param and sysfs checks, but
 the module ones were stronger so we weakened them temporarily).
 
 Param parsing gets documented, and also "--" now forces args to be
 handed to init (and ignored by the kernel).
 
 Module NX/RO protections get tightened: we now set them before calling
 parse_args().
 
 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:
 "Most of this is cleaning up various driver sysfs permissions so we can
  re-add the perm check (we unified the module param and sysfs checks,
  but the module ones were stronger so we weakened them temporarily).

  Param parsing gets documented, and also "--" now forces args to be
  handed to init (and ignored by the kernel).

  Module NX/RO protections get tightened: we now set them before calling
  parse_args()"

* tag 'modules-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux:
  module: set nx before marking module MODULE_STATE_COMING.
  samples/kobject/: avoid world-writable sysfs files.
  drivers/hid/hid-picolcd_fb: avoid world-writable sysfs files.
  drivers/staging/speakup/: avoid world-writable sysfs files.
  drivers/regulator/virtual: avoid world-writable sysfs files.
  drivers/scsi/pm8001/pm8001_ctl.c: avoid world-writable sysfs files.
  drivers/hid/hid-lg4ff.c: avoid world-writable sysfs files.
  drivers/video/fbdev/sm501fb.c: avoid world-writable sysfs files.
  drivers/mtd/devices/docg3.c: avoid world-writable sysfs files.
  speakup: fix incorrect perms on speakup_acntsa.c
  cpumask.h: silence warning with -Wsign-compare
  Documentation: Update kernel-parameters.tx
  param: hand arguments after -- straight to init
  modpost: Fix resource leak in read_dump()
2014-06-11 16:09:14 -07:00
Linus Torvalds 2071b3e34f Merge branch 'x86/espfix' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip into next
Pull x86-64 espfix changes from Peter Anvin:
 "This is the espfix64 code, which fixes the IRET information leak as
  well as the associated functionality problem.  With this code applied,
  16-bit stack segments finally work as intended even on a 64-bit
  kernel.

  Consequently, this patchset also removes the runtime option that we
  added as an interim measure.

  To help the people working on Linux kernels for very small systems,
  this patchset also makes these compile-time configurable features"

* 'x86/espfix' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  Revert "x86-64, modify_ldt: Make support for 16-bit segments a runtime option"
  x86, espfix: Make it possible to disable 16-bit support
  x86, espfix: Make espfix64 a Kconfig option, fix UML
  x86, espfix: Fix broken header guard
  x86, espfix: Move espfix definitions into a separate header file
  x86-32, espfix: Remove filter for espfix32 due to race
  x86-64, espfix: Don't leak bits 31:16 of %esp returning to 16-bit stack
2014-06-05 07:46:15 -07:00
Andrew Morton 647f010bff init/main.c: remove an ifdef
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:54:21 -07:00
Oleg Nesterov 34a1b7236a kthreads: kill CLONE_KERNEL, change kernel_thread(kernel_init) to avoid CLONE_SIGHAND
1. Remove CLONE_KERNEL, it has no users and it is dangerous.

   The (old) comment says "List of flags we want to share for kernel
   threads" but this is not true, we do not want to share ->sighand by
   default. This flag can only be used if the caller is sure that both
   parent/child will never play with signals (say, allow_signal/etc).

2. Change rest_init() to clone kernel_init() without CLONE_SIGHAND.

   In this case CLONE_SIGHAND does not really hurt, and it looks like
   optimization because copy_sighand() can avoid kmem_cache_alloc().

   But in fact this only adds the minor pessimization. kernel_init()
   is going to exec the init process, and de_thread() will need to
   unshare ->sighand and do kmem_cache_alloc(sighand_cachep) anyway,
   but it needs to do more work and take tasklist_lock and siglock.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:54:21 -07:00
Prarit Bhargava 7b0b73d766 init/main.c: add initcall_blacklist kernel parameter
When a module is built into the kernel the module_init() function
becomes an initcall.  Sometimes debugging through dynamic debug can
help, however, debugging built in kernel modules is typically done by
changing the .config, recompiling, and booting the new kernel in an
effort to determine exactly which module caused a problem.

This patchset can be useful stand-alone or combined with initcall_debug.
There are cases where some initcalls can hang the machine before the
console can be flushed, which can make initcall_debug output inaccurate.
Having the ability to skip initcalls can help further debugging of these
scenarios.

Usage: initcall_blacklist=<list of comma separated initcalls>

ex) added "initcall_blacklist=sgi_uv_sysfs_init" as a kernel parameter and
the log contains:

	blacklisting initcall sgi_uv_sysfs_init
	...
	...
	initcall sgi_uv_sysfs_init blacklisted

ex) added "initcall_blacklist=foo_bar,sgi_uv_sysfs_init" as a kernel parameter
and the log contains:

	blacklisting initcall foo_bar
	blacklisting initcall sgi_uv_sysfs_init
	...
	...
	initcall sgi_uv_sysfs_init blacklisted

[akpm@linux-foundation.org: tweak printk text]
Signed-off-by: Prarit Bhargava <prarit@redhat.com>
Cc: Richard Weinberger <richard.weinberger@gmail.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Josh Boyer <jwboyer@fedoraproject.org>
Cc: Rob Landley <rob@landley.net>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:54:21 -07:00