path: root/kernel (follow)
AgeCommit message (Collapse)AuthorFilesLines
2015-02-17kexec: fix a typo in commentAlexander Kuleshov1-1/+1
Signed-off-by: Alexander Kuleshov <kuleshovmail@gmail.com> Acked-by: "Eric W. Biederman" <ebiederm@xmission.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>
2015-02-17kexec: remove never used member destination in kimageBaoquan He1-4/+0
struct kimage has a member destination which is used to store the real destination address of each page when load segment from user space buffer to kernel. But we never retrieve the value stored in kimage->destination, so this member variable in kimage and its assignment operation are redundent code. I guess for_each_kimage_entry just does the work that kimage->destination is expected to do. So in this patch just make a cleanup to remove it. Signed-off-by: Baoquan He <bhe@redhat.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-17signal: use current->state helpersDavidlohr Bueso1-2/+2
Call __set_current_state() instead of assigning the new state directly. These interfaces also aid CONFIG_DEBUG_ATOMIC_SLEEP environments, keeping track of who changed the state. Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Acked-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-17ptrace: remove linux/compat.h inclusion under CONFIG_COMPATFabian Frederick1-1/+0
Commit 84c751bd4aeb ("ptrace: add ability to retrieve signals without removing from a queue (v4)") includes <linux/compat.h> globally in ptrace.c This patch removes inclusion under if defined CONFIG_COMPAT. Signed-off-by: Fabian Frederick <fabf@skynet.be> Acked-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-17Merge tag 'suspend-to-idle-3.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pmLinus Torvalds5-17/+142
Pull suspend-to-idle updates from Rafael Wysocki: "Suspend-to-idle timer quiescing support for v3.20-rc1 Until now suspend-to-idle has not been able to save much more energy than runtime PM because of timer interrupts that periodically bring CPUs out of idle while they are waiting for a wakeup interrupt. Of course, the timer interrupts are not wakeup ones, so the handling of them can be deferred until a real wakeup interrupt happens, but at the same time we don't want to mass-expire timers at that point. The solution is to suspend the entire timekeeping when the last CPU is entering an idle state and resume it when the first CPU goes out of idle. That has to be done with care, though, so as to avoid accessing suspended clocksources etc. end we need extra support from idle drivers for that. This series of commits adds support for quiescing timers during suspend-to-idle and adds the requisite callbacks to intel_idle and the ACPI cpuidle driver" * tag 'suspend-to-idle-3.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: ACPI / idle: Implement ->enter_freeze callback routine intel_idle: Add ->enter_freeze callbacks PM / sleep: Make it possible to quiesce timers during suspend-to-idle timekeeping: Make it safe to use the fast timekeeper while suspended timekeeping: Pass readout base to update_fast_timekeeper() PM / sleep: Re-implement suspend-to-idle handling
2015-02-16Merge branch 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds1-0/+3
Pull irqchip updates from Ingo Molnar: "Various irqchip driver updates, plus a genirq core update that allows the initial spreading of irqs amonst CPUs without having to do it from user-space" * 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: genirq: Fix null pointer reference in irq_set_affinity_hint() irqchip: gic: Allow interrupt level to be set for PPIs irqchip: mips-gic: Handle pending interrupts once in __gic_irq_dispatch() irqchip: Conexant CX92755 interrupts controller driver irqchip: Devicetree: document Conexant Digicolor irq binding irqchip: omap-intc: Remove unused legacy interface for omap2 irqchip: omap-intc: Fix support for dm814 and dm816 irqchip: mtk-sysirq: Get irq number from register resource size irqchip: renesas-intc-irqpin: r8a7779 IRLM setup support genirq: Set initial affinity in irq_set_affinity_hint()
2015-02-16Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds1-2/+12
Pull x86 perf updates from Ingo Molnar: "This series tightens up RDPMC permissions: currently even highly sandboxed x86 execution environments (such as seccomp) have permission to execute RDPMC, which may leak various perf events / PMU state such as timing information and other CPU execution details. This 'all is allowed' RDPMC mode is still preserved as the (non-default) /sys/devices/cpu/rdpmc=2 setting. The new default is that RDPMC access is only allowed if a perf event is mmap-ed (which is needed to correctly interpret RDPMC counter values in any case). As a side effect of these changes CR4 handling is cleaned up in the x86 code and a shadow copy of the CR4 value is added. The extra CR4 manipulation adds ~ <50ns to the context switch cost between rdpmc-capable and rdpmc-non-capable mms" * 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf/x86: Add /sys/devices/cpu/rdpmc=2 to allow rdpmc for all tasks perf/x86: Only allow rdpmc if a perf_event is mapped perf: Pass the event to arch_perf_update_userpage() perf: Add pmu callbacks to track event mapping and unmapping x86: Add a comment clarifying LDT context switching x86: Store a per-cpu shadow copy of CR4 x86: Clean up cr4 manipulation
2015-02-16livepatch: fix format string in kobject_init_and_add()Jiri Kosina1-2/+2
kobject_init_and_add() takes expects format string for a name, so we better provide it in order to avoid infoleaks if modules craft their mod->name in a special way. Reported-by: Fengguang Wu <fengguang.wu@intel.com> Reported-by: Kees Cook <keescook@chromium.org> Acked-by: Seth Jennings <sjenning@redhat.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2015-02-15PM / sleep: Make it possible to quiesce timers during suspend-to-idleRafael J. Wysocki3-2/+54
The efficiency of suspend-to-idle depends on being able to keep CPUs in the deepest available idle states for as much time as possible. Ideally, they should only be brought out of idle by system wakeup interrupts. However, timer interrupts occurring periodically prevent that from happening and it is not practical to chase all of the "misbehaving" timers in a whack-a-mole fashion. A much more effective approach is to suspend the local ticks for all CPUs and the entire timekeeping along the lines of what is done during full suspend, which also helps to keep suspend-to-idle and full suspend reasonably similar. The idea is to suspend the local tick on each CPU executing cpuidle_enter_freeze() and to make the last of them suspend the entire timekeeping. That should prevent timer interrupts from triggering until an IO interrupt wakes up one of the CPUs. It needs to be done with interrupts disabled on all of the CPUs, though, because otherwise the suspended clocksource might be accessed by an interrupt handler which might lead to fatal consequences. Unfortunately, the existing ->enter callbacks provided by cpuidle drivers generally cannot be used for implementing that, because some of them re-enable interrupts temporarily and some idle entry methods cause interrupts to be re-enabled automatically on exit. Also some of these callbacks manipulate local clock event devices of the CPUs which really shouldn't be done after suspending their ticks. To overcome that difficulty, introduce a new cpuidle state callback, ->enter_freeze, that will be guaranteed (1) to keep interrupts disabled all the time (and return with interrupts disabled) and (2) not to touch the CPU timer devices. Modify cpuidle_enter_freeze() to look for the deepest available idle state with ->enter_freeze present and to make the CPU execute that callback with suspended tick (and the last of the online CPUs to execute it with suspended timekeeping). Suggested-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
2015-02-15timekeeping: Make it safe to use the fast timekeeper while suspendedRafael J. Wysocki1-0/+30
Theoretically, ktime_get_mono_fast_ns() may be executed after timekeeping has been suspended (or before it is resumed) which in turn may lead to undefined behavior, for example, when the clocksource read from timekeeping_get_ns() called by it is not accessible at that time. Prevent that from happening by setting up a dummy readout base for the fast timekeeper during timekeeping_suspend() such that it will always return the same number of cycles. After the last timekeeping_update() in timekeeping_suspend() the clocksource is read and the result is stored as cycles_at_suspend. The readout base from the current timekeeper is copied onto the dummy and the ->read pointer of the dummy is set to a routine unconditionally returning cycles_at_suspend. Next, the dummy is passed to update_fast_timekeeper(). Then, ktime_get_mono_fast_ns() will work until the subsequent timekeeping_resume() and the proper readout base for the fast timekeeper will be restored by the timekeeping_update() called right after clearing timekeeping_suspended. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: John Stultz <john.stultz@linaro.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
2015-02-13kprobes: makes kprobes/enabled works correctly for optimized kprobes.Wang Nan1-2/+9
debugfs/kprobes/enabled doesn't work correctly on optimized kprobes. Masami Hiramatsu has a test report on x86_64 platform: https://lkml.org/lkml/2015/1/19/274 This patch forces it to unoptimize kprobe if kprobes_all_disarmed is set. It also checks the flag in unregistering path for skipping unneeded disarming process when kprobes globally disarmed. Signed-off-by: Wang Nan <wangnan0@huawei.com> Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Ingo Molnar <mingo@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-13kprobes: set kprobes_all_disarmed earlier to enable re-optimization.Wang Nan1-1/+6
In original code, the probed instruction doesn't get optimized after echo 0 > /sys/kernel/debug/kprobes/enabled echo 1 > /sys/kernel/debug/kprobes/enabled This is because original code checks kprobes_all_disarmed in optimize_kprobe(), but this flag is turned off after calling that function. Therefore, optimize_kprobe() will see kprobes_all_disarmed == true and doesn't do the optimization. This patch simply turns off kprobes_all_disarmed earlier to enable optimization. Signed-off-by: Wang Nan <wangnan0@huawei.com> Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Ingo Molnar <mingo@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-13kasan: enable instrumentation of global variablesAndrey Ryabinin1-0/+2
This feature let us to detect accesses out of bounds of global variables. This will work as for globals in kernel image, so for globals in modules. Currently this won't work for symbols in user-specified sections (e.g. __init, __read_mostly, ...) The idea of this is simple. Compiler increases each global variable by redzone size and add constructors invoking __asan_register_globals() function. Information about global variable (address, size, size with redzone ...) passed to __asan_register_globals() so we could poison variable's redzone. This patch also forces module_alloc() to return 8*PAGE_SIZE aligned address making shadow memory handling ( kasan_module_alloc()/kasan_module_free() ) more simple. Such alignment guarantees that each shadow page backing modules address space correspond to only one module_alloc() allocation. Signed-off-by: Andrey Ryabinin <a.ryabinin@samsung.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Konstantin Serebryany <kcc@google.com> Cc: Dmitry Chernenkov <dmitryc@google.com> Signed-off-by: Andrey Konovalov <adech.fo@gmail.com> Cc: Yuri Gribov <tetra2005@gmail.com> Cc: Konstantin Khlebnikov <koct9i@gmail.com> Cc: Sasha Levin <sasha.levin@oracle.com> Cc: Christoph Lameter <cl@linux.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-13profile: use %*pb[l] to print bitmaps including cpumasks and nodemasksTejun Heo1-2/+1
printk and friends can now format bitmaps using '%*pb[l]'. cpumask and nodemask also provide cpumask_pr_args() and nodemask_pr_args() respectively which can be used to generate the two printf arguments necessary to format the specified cpu/nodemask. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-13irq: use %*pb[l] to print bitmaps including cpumasks and nodemasksTejun Heo1-7/+4
printk and friends can now format bitmaps using '%*pb[l]'. cpumask and nodemask also provide cpumask_pr_args() and nodemask_pr_args() respectively which can be used to generate the two printf arguments necessary to format the specified cpu/nodemask. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-13padata: use %*pb[l] to print bitmaps including cpumasks and nodemasksTejun Heo1-8/+3
printk and friends can now format bitmaps using '%*pb[l]'. cpumask and nodemask also provide cpumask_pr_args() and nodemask_pr_args() respectively which can be used to generate the two printf arguments necessary to format the specified cpu/nodemask. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-13tracing: use %*pb[l] to print bitmaps including cpumasks and nodemasksTejun Heo2-4/+4
printk and friends can now format bitmaps using '%*pb[l]'. cpumask and nodemask also provide cpumask_pr_args() and nodemask_pr_args() respectively which can be used to generate the two printf arguments necessary to format the specified cpu/nodemask. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Ingo Molnar <mingo@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-13workqueue: use %*pb[l] to format bitmaps including cpumasks and nodemasksTejun Heo1-3/+2
printk and friends can now format bitmaps using '%*pb[l]'. cpumask and nodemask also provide cpumask_pr_args() and nodemask_pr_args() respectively which can be used to generate the two printf arguments necessary to format the specified cpu/nodemask. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-13time: use %*pb[l] to print bitmaps including cpumasks and nodemasksTejun Heo1-9/+2
printk and friends can now format bitmaps using '%*pb[l]'. cpumask and nodemask also provide cpumask_pr_args() and nodemask_pr_args() respectively which can be used to generate the two printf arguments necessary to format the specified cpu/nodemask. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-13sched: use %*pb[l] to print bitmaps including cpumasks and nodemasksTejun Heo2-15/+6
printk and friends can now format bitmaps using '%*pb[l]'. cpumask and nodemask also provide cpumask_pr_args() and nodemask_pr_args() respectively which can be used to generate the two printf arguments necessary to format the specified cpu/nodemask. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-13rcu: use %*pb[l] to print bitmaps including cpumasks and nodemasksTejun Heo1-3/+2
printk and friends can now format bitmaps using '%*pb[l]'. cpumask and nodemask also provide cpumask_pr_args() and nodemask_pr_args() respectively which can be used to generate the two printf arguments necessary to format the specified cpu/nodemask. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-13cpuset: use %*pb[l] to print bitmaps including cpumasks and nodemasksTejun Heo1-33/+9
printk and friends can now format bitmaps using '%*pb[l]'. cpumask and nodemask also provide cpumask_pr_args() and nodemask_pr_args() respectively which can be used to generate the two printf arguments necessary to format the specified cpu/nodemask. * kernel/cpuset.c::cpuset_print_task_mems_allowed() used a static buffer which is protected by a dedicated spinlock. Removed. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Li Zefan <lizefan@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-13kernfs: remove KERNFS_STATIC_NAMETejun Heo1-1/+1
When a new kernfs node is created, KERNFS_STATIC_NAME is used to avoid making a separate copy of its name. It's currently only used for sysfs attributes whose filenames are required to stay accessible and unchanged. There are rare exceptions where these names are allocated and formatted dynamically but for the vast majority of cases they're consts in the rodata section. Now that kernfs is converted to use kstrdup_const() and kfree_const(), there's little point in keeping KERNFS_STATIC_NAME around. Remove it. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Andrzej Hajda <a.hajda@samsung.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-13timekeeping: Pass readout base to update_fast_timekeeper()Rafael J. Wysocki1-8/+6
Modify update_fast_timekeeper() to take a struct tk_read_base pointer as its argument (instead of a struct timekeeper pointer) and update its kerneldoc comment to reflect that. That will allow a struct tk_read_base that is not part of a struct timekeeper to be passed to it in the next patch. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: John Stultz <john.stultz@linaro.org>
2015-02-13PM / sleep: Re-implement suspend-to-idle handlingRafael J. Wysocki2-7/+52
In preparation for adding support for quiescing timers in the final stage of suspend-to-idle transitions, rework the freeze_enter() function making the system wait on a wakeup event, the freeze_wake() function terminating the suspend-to-idle loop and the mechanism by which deep idle states are entered during suspend-to-idle. First of all, introduce a simple state machine for suspend-to-idle and make the code in question use it. Second, prevent freeze_enter() from losing wakeup events due to race conditions and ensure that the number of online CPUs won't change while it is being executed. In addition to that, make it force all of the CPUs re-enter the idle loop in case they are in idle states already (so they can enter deeper idle states if possible). Next, drop cpuidle_use_deepest_state() and replace use_deepest_state checks in cpuidle_select() and cpuidle_reflect() with a single suspend-to-idle state check in cpuidle_idle_call(). Finally, introduce cpuidle_enter_freeze() that will simply find the deepest idle state available to the given CPU and enter it using cpuidle_enter(). Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
2015-02-13Merge tag 'modules-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linuxLinus Torvalds1-29/+18
Pull module update from Rusty Russell: "Trivial cleanups, mainly" * tag 'modules-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux: module: Replace over-engineered nested sleep module: Annotate nested sleep in resolve_symbol() module: Remove double spaces in module verification taint message kernel/module.c: Free lock-classes if parse_args failed module: set ksymtab/kcrctab* section addresses to 0x0
2015-02-12printk: correct timeout comment, neaten MODULE_PARM_DESCJoe Perches1-6/+6
Neaten the MODULE_PARAM_DESC message. Use 30 seconds in the comment for the zap console locks timeout. Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-12kernel/sched/clock.c: add another clock for use with the soft lockup watchdogCyril Bur2-1/+14
When the hypervisor pauses a virtualised kernel the kernel will observe a jump in timebase, this can cause spurious messages from the softlockup detector. Whilst these messages are harmless, they are accompanied with a stack trace which causes undue concern and more problematically the stack trace in the guest has nothing to do with the observed problem and can only be misleading. Futhermore, on POWER8 this is completely avoidable with the introduction of the Virtual Time Base (VTB) register. This patch (of 2): This permits the use of arch specific clocks for which virtualised kernels can use their notion of 'running' time, not the elpased wall time which will include host execution time. Signed-off-by: Cyril Bur <cyrilbur@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Andrew Jones <drjones@redhat.com> Acked-by: Don Zickus <dzickus@redhat.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Ulrich Obergfell <uobergfe@redhat.com> Cc: chai wen <chaiw.fnst@cn.fujitsu.com> Cc: Fabian Frederick <fabf@skynet.be> Cc: Aaron Tomlin <atomlin@redhat.com> Cc: Ben Zhang <benzh@chromium.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: John Stultz <john.stultz@linaro.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-12all arches, signal: move restart_block to struct task_structAndy Lutomirski6-9/+7
If an attacker can cause a controlled kernel stack overflow, overwriting the restart block is a very juicy exploit target. This is because the restart_block is held in the same memory allocation as the kernel stack. Moving the restart block to struct task_struct prevents this exploit by making the restart_block harder to locate. Note that there are other fields in thread_info that are also easy targets, at least on some architectures. It's also a decent simplification, since the restart code is more or less identical on all architectures. [james.hogan@imgtec.com: metag: align thread_info::supervisor_stack] Signed-off-by: Andy Lutomirski <luto@amacapital.net> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Kees Cook <keescook@chromium.org> Cc: David Miller <davem@davemloft.net> Acked-by: Richard Weinberger <richard@nod.at> Cc: Richard Henderson <rth@twiddle.net> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Matt Turner <mattst88@gmail.com> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Russell King <rmk@arm.linux.org.uk> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Haavard Skinnemoen <hskinnemoen@gmail.com> Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no> Cc: Steven Miao <realmz6@gmail.com> Cc: Mark Salter <msalter@redhat.com> Cc: Aurelien Jacquiot <a-jacquiot@ti.com> Cc: Mikael Starvik <starvik@axis.com> Cc: Jesper Nilsson <jesper.nilsson@axis.com> Cc: David Howells <dhowells@redhat.com> Cc: Richard Kuo <rkuo@codeaurora.org> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Michal Simek <monstr@monstr.eu> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Jonas Bonn <jonas@southpole.se> Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> Cc: Helge Deller <deller@gmx.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc) Tested-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc) Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Chen Liqin <liqin.linux@gmail.com> Cc: Lennox Wu <lennox.wu@gmail.com> Cc: Chris Metcalf <cmetcalf@ezchip.com> Cc: Guan Xuetao <gxt@mprc.pku.edu.cn> Cc: Chris Zankel <chris@zankel.net> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Guenter Roeck <linux@roeck-us.net> Signed-off-by: James Hogan <james.hogan@imgtec.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-12kernel/cpuset.c: Mark cpuset_init_current_mems_allowed as __initRasmus Villemoes1-1/+1
The only caller of cpuset_init_current_mems_allowed is the __init annotated build_all_zonelists_init, so we can also make the former __init. Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Rik van Riel <riel@redhat.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: David Rientjes <rientjes@google.com> Cc: Vishnu Pratap Singh <vishnu.ps@samsung.com> Cc: Pintu Kumar <pintu.k@samsung.com> Cc: Michal Nazarewicz <mina86@mina86.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: Hugh Dickins <hughd@google.com> Cc: Li Zefan <lizefan@huawei.com> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-12mm: do not use mm->nr_pmds on !MMU configurationsKirill A. Shutemov1-3/+1
mm->nr_pmds doesn't make sense on !MMU configurations Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> 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>
2015-02-12cgroup: release css->id after css_freeVladimir Davydov1-3/+7
Currently, we release css->id in css_release_work_fn, right before calling css_free callback, so that when css_free is called, the id may have already been reused for a new cgroup. I am going to use css->id to create unique names for per memcg kmem caches. Since kmem caches are destroyed only on css_free, I need css->id to be freed after css_free was called to avoid name clashes. This patch therefore moves css->id removal to css_free_work_fn. To prevent css_from_id from returning a pointer to a stale css, it makes css_release_work_fn replace the css ptr at css_idr:css->id with NULL. Signed-off-by: Vladimir Davydov <vdavydov@parallels.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Acked-by: Tejun Heo <tj@kernel.org> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Dave Chinner <david@fromorbit.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-12Merge branch 'for-linus' of git://ftp.arm.linux.org.uk/~rmk/linux-armLinus Torvalds1-2/+2
Pull ARM updates from Russell King: - clang assembly fixes from Ard - optimisations and cleanups for Aurora L2 cache support - efficient L2 cache support for secure monitor API on Exynos SoCs - debug menu cleanup from Daniel Thompson to allow better behaviour for multiplatform kernels - StrongARM SA11x0 conversion to irq domains, and pxa_timer - kprobes updates for older ARM CPUs - move probes support out of arch/arm/kernel to arch/arm/probes - add inline asm support for the rbit (reverse bits) instruction - provide an ARM mode secondary CPU entry point (for Qualcomm CPUs) - remove the unused ARMv3 user access code - add driver_override support to AMBA Primecell bus * 'for-linus' of git://ftp.arm.linux.org.uk/~rmk/linux-arm: (55 commits) ARM: 8256/1: driver coamba: add device binding path 'driver_override' ARM: 8301/1: qcom: Use secondary_startup_arm() ARM: 8302/1: Add a secondary_startup that assumes ARM mode ARM: 8300/1: teach __asmeq that r11 == fp and r12 == ip ARM: kprobes: Fix compilation error caused by superfluous '*' ARM: 8297/1: cache-l2x0: optimize aurora range operations ARM: 8296/1: cache-l2x0: clean up aurora cache handling ARM: 8284/1: sa1100: clear RCSR_SMR on resume ARM: 8283/1: sa1100: collie: clear PWER register on machine init ARM: 8282/1: sa1100: use handle_domain_irq ARM: 8281/1: sa1100: move GPIO-related IRQ code to gpio driver ARM: 8280/1: sa1100: switch to irq_domain_add_simple() ARM: 8279/1: sa1100: merge both GPIO irqdomains ARM: 8278/1: sa1100: split irq handling for low GPIOs ARM: 8291/1: replace magic number with PAGE_SHIFT macro in fixup_pv code ARM: 8290/1: decompressor: fix a wrong comment ARM: 8286/1: mm: Fix dma_contiguous_reserve comment ARM: 8248/1: pm: remove outdated comment ARM: 8274/1: Fix DEBUG_LL for multi-platform kernels (without PL01X) ARM: 8273/1: Seperate DEBUG_UART_PHYS from DEBUG_LL on EP93XX ...
2015-02-12Merge tag 'trace-v3.20' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-traceLinus Torvalds19-150/+175
Pull tracing updates from Steven Rostedt: "The updates included in this pull request for ftrace are: o Several clean ups to the code One such clean up was to convert to 64 bit time keeping, in the ring buffer benchmark code. o Adding of __print_array() helper macro for TRACE_EVENT() o Updating the sample/trace_events/ to add samples of different ways to make trace events. Lots of features have been added since the sample code was made, and these features are mostly unknown. Developers have been making their own hacks to do things that are already available. o Performance improvements. Most notably, I found a performance bug where a waiter that is waiting for a full page from the ring buffer will see that a full page is not available, and go to sleep. The sched event caused by it going to sleep would cause it to wake up again. It would see that there was still not a full page, and go back to sleep again, and that would wake it up again, until finally it would see a full page. This change has been marked for stable. Other improvements include removing global locks from fast paths" * tag 'trace-v3.20' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: ring-buffer: Do not wake up a splice waiter when page is not full tracing: Fix unmapping loop in tracing_mark_write tracing: Add samples of DECLARE_EVENT_CLASS() and DEFINE_EVENT() tracing: Add TRACE_EVENT_FN example tracing: Add TRACE_EVENT_CONDITION sample tracing: Update the TRACE_EVENT fields available in the sample code tracing: Separate out initializing top level dir from instances tracing: Make tracing_init_dentry_tr() static trace: Use 64-bit timekeeping tracing: Add array printing helper tracing: Remove newline from trace_printk warning banner tracing: Use IS_ERR() check for return value of tracing_init_dentry() tracing: Remove unneeded includes of debugfs.h and fs.h tracing: Remove taking of trace_types_lock in pipe files tracing: Add ref count to tracer for when they are being read by pipe
2015-02-12MIPS,prctl: add PR_[GS]ET_FP_MODE prctl options for MIPSPaul Burton1-0/+12
Userland code may be built using an ABI which permits linking to objects that have more restrictive floating point requirements. For example, userland code may be built to target the O32 FPXX ABI. Such code may be linked with other FPXX code, or code built for either one of the more restrictive FP32 or FP64. When linking with more restrictive code, the overall requirement of the process becomes that of the more restrictive code. The kernel has no way to know in advance which mode the process will need to be executed in, and indeed it may need to change during execution. The dynamic loader is the only code which will know the overall required mode, and so it needs to have a means to instruct the kernel to switch the FP mode of the process. This patch introduces 2 new options to the prctl syscall which provide such a capability. The FP mode of the process is represented as a simple bitmask combining a number of mode bits mirroring those present in the hardware. Userland can either retrieve the current FP mode of the process: mode = prctl(PR_GET_FP_MODE); or modify the current FP mode of the process: err = prctl(PR_SET_FP_MODE, new_mode); Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: Matthew Fortune <matthew.fortune@imgtec.com> Cc: Markos Chandras <markos.chandras@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/8899/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-02-11Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-securityLinus Torvalds1-1/+1
Pull security layer updates from James Morris: "Highlights: - Smack adds secmark support for Netfilter - /proc/keys is now mandatory if CONFIG_KEYS=y - TPM gets its own device class - Added TPM 2.0 support - Smack file hook rework (all Smack users should review this!)" * 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (64 commits) cipso: don't use IPCB() to locate the CIPSO IP option SELinux: fix error code in policydb_init() selinux: add security in-core xattr support for pstore and debugfs selinux: quiet the filesystem labeling behavior message selinux: Remove unused function avc_sidcmp() ima: /proc/keys is now mandatory Smack: Repair netfilter dependency X.509: silence asn1 compiler debug output X.509: shut up about included cert for silent build KEYS: Make /proc/keys unconditional if CONFIG_KEYS=y MAINTAINERS: email update tpm/tpm_tis: Add missing ifdef CONFIG_ACPI for pnp_acpi_device smack: fix possible use after frees in task_security() callers smack: Add missing logging in bidirectional UDS connect check Smack: secmark support for netfilter Smack: Rework file hooks tpm: fix format string error in tpm-chip.c char/tpm/tpm_crb: fix build error smack: Fix a bidirectional UDS connect check typo smack: introduce a special case for tmpfs in smack_d_instantiate() ...
2015-02-11Merge branch 'upstream' of git://git.infradead.org/users/pcmoore/auditLinus Torvalds1-2/+0
Pull audit fix from Paul Moore: "Just one patch from the audit tree for v3.20, and a very minor one at that. The patch simply removes an old, unused field from the audit_krule structure, a private audit-only struct. In audit related news, we did a proper overhaul of the audit pathname code and removed the nasty getname()/putname() hacks for audit, you should see those patches in Al's vfs tree if you haven't already. That's it for audit this time, let's hope for a quiet -rcX series" * 'upstream' of git://git.infradead.org/users/pcmoore/audit: audit: remove vestiges of vers_ops
2015-02-11Merge branch 'akpm' (patches from Andrew)Linus Torvalds3-54/+35
Merge second set of updates from Andrew Morton: "More of MM" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (83 commits) mm/nommu.c: fix arithmetic overflow in __vm_enough_memory() mm/mmap.c: fix arithmetic overflow in __vm_enough_memory() vmstat: Reduce time interval to stat update on idle cpu mm/page_owner.c: remove unnecessary stack_trace field Documentation/filesystems/proc.txt: describe /proc/<pid>/map_files mm: incorporate read-only pages into transparent huge pages vmstat: do not use deferrable delayed work for vmstat_update mm: more aggressive page stealing for UNMOVABLE allocations mm: always steal split buddies in fallback allocations mm: when stealing freepages, also take pages created by splitting buddy page mincore: apply page table walker on do_mincore() mm: /proc/pid/clear_refs: avoid split_huge_page() mm: pagewalk: fix misbehavior of walk_page_range for vma(VM_PFNMAP) mempolicy: apply page table walker on queue_pages_range() arch/powerpc/mm/subpage-prot.c: use walk->vma and walk_page_vma() memcg: cleanup preparation for page table walk numa_maps: remove numa_maps->vma numa_maps: fix typo in gather_hugetbl_stats pagemap: use walk->vma instead of calling find_vma() clear_refs: remove clear_refs_private->vma and introduce clear_refs_test_walk() ...
2015-02-11Merge tag 'powerpc-3.20-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mpe/linuxLinus Torvalds1-0/+12
Pull powerpc updates from Michael Ellerman: - Update of all defconfigs - Addition of a bunch of config options to modernise our defconfigs - Some PS3 updates from Geoff - Optimised memcmp for 64 bit from Anton - Fix for kprobes that allows 'perf probe' to work from Naveen - Several cxl updates from Ian & Ryan - Expanded support for the '24x7' PMU from Cody & Sukadev - Freescale updates from Scott: "Highlights include 8xx optimizations, some more work on datapath device tree content, e300 machine check support, t1040 corenet error reporting, and various cleanups and fixes" * tag 'powerpc-3.20-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mpe/linux: (102 commits) cxl: Add missing return statement after handling AFU errror cxl: Fail AFU initialisation if an invalid configuration record is found cxl: Export optional AFU configuration record in sysfs powerpc/mm: Warn on flushing tlb page in kernel context powerpc/powernv: Add OPAL soft-poweroff routine powerpc/perf/hv-24x7: Document sysfs event description entries powerpc/perf/hv-gpci: add the remaining gpci requests powerpc/perf/{hv-gpci, hv-common}: generate requests with counters annotated powerpc/perf/hv-24x7: parse catalog and populate sysfs with events perf: define EVENT_DEFINE_RANGE_FORMAT_LITE helper perf: add PMU_EVENT_ATTR_STRING() helper perf: provide sysfs_show for struct perf_pmu_events_attr powerpc/kernel: Avoid initializing device-tree pointer twice powerpc: Remove old compile time disabled syscall tracing code powerpc/kernel: Make syscall_exit a local label cxl: Fix device_node reference counting powerpc/mm: bail out early when flushing TLB page powerpc: defconfigs: add MTD_SPI_NOR (new dependency for M25P80) perf/powerpc: reset event hw state when adding it to the PMU powerpc/qe: Use strlcpy() ...
2015-02-11Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linuxLinus Torvalds5-10/+10
Pull s390 updates from Martin Schwidefsky: - The remaining patches for the z13 machine support: kernel build option for z13, the cache synonym avoidance, SMT support, compare-and-delay for spinloops and the CES5S crypto adapater. - The ftrace support for function tracing with the gcc hotpatch option. This touches common code Makefiles, Steven is ok with the changes. - The hypfs file system gets an extension to access diagnose 0x0c data in user space for performance analysis for Linux running under z/VM. - The iucv hvc console gets wildcard spport for the user id filtering. - The cacheinfo code is converted to use the generic infrastructure. - Cleanup and bug fixes. * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (42 commits) s390/process: free vx save area when releasing tasks s390/hypfs: Eliminate hypfs interval s390/hypfs: Add diagnose 0c support s390/cacheinfo: don't use smp_processor_id() in preemptible context s390/zcrypt: fixed domain scanning problem (again) s390/smp: increase maximum value of NR_CPUS to 512 s390/jump label: use different nop instruction s390/jump label: add sanity checks s390/mm: correct missing space when reporting user process faults s390/dasd: cleanup profiling s390/dasd: add locking for global_profile access s390/ftrace: hotpatch support for function tracing ftrace: let notrace function attribute disable hotpatching if necessary ftrace: allow architectures to specify ftrace compile options s390: reintroduce diag 44 calls for cpu_relax() s390/zcrypt: Add support for new crypto express (CEX5S) adapter. s390/zcrypt: Number of supported ap domains is not retrievable. s390/spinlock: add compare-and-delay to lock wait loops s390/tape: remove redundant if statement s390/hvc_iucv: add simple wildcard matches to the iucv allow filter ...
2015-02-11mm: fix false-positive warning on exit due mm_nr_pmds(mm)Kirill A. Shutemov1-0/+8
The problem is that we check nr_ptes/nr_pmds in exit_mmap() which happens *before* pgd_free(). And if an arch does pte/pmd allocation in pgd_alloc() and frees them in pgd_free() we see offset in counters by the time of the checks. We tried to workaround this by offsetting expected counter value according to FIRST_USER_ADDRESS for both nr_pte and nr_pmd in exit_mmap(). But it doesn't work in some cases: 1. ARM with LPAE enabled also has non-zero USER_PGTABLES_CEILING, but upper addresses occupied with huge pmd entries, so the trick with offsetting expected counter value will get really ugly: we will have to apply it nr_pmds, but not nr_ptes. 2. Metag has non-zero FIRST_USER_ADDRESS, but doesn't do allocation pte/pmd page tables allocation in pgd_alloc(), just setup a pgd entry which is allocated at boot and shared accross all processes. The proposal is to move the check to check_mm() which happens *after* pgd_free() and do proper accounting during pgd_alloc() and pgd_free() which would bring counters to zero if nothing leaked. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reported-by: Tyler Baker <tyler.baker@linaro.org> Tested-by: Tyler Baker <tyler.baker@linaro.org> Tested-by: Nishanth Menon <nm@ti.com> Cc: Russell King <linux@arm.linux.org.uk> Cc: James Hogan <james.hogan@imgtec.com> Cc: Guan Xuetao <gxt@mprc.pku.edu.cn> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-11mm: account pmd page tables to the processKirill A. Shutemov1-0/+3
Dave noticed that unprivileged process can allocate significant amount of memory -- >500 MiB on x86_64 -- and stay unnoticed by oom-killer and memory cgroup. The trick is to allocate a lot of PMD page tables. Linux kernel doesn't account PMD tables to the process, only PTE. The use-cases below use few tricks to allocate a lot of PMD page tables while keeping VmRSS and VmPTE low. oom_score for the process will be 0. #include <errno.h> #include <stdio.h> #include <stdlib.h> #include <unistd.h> #include <sys/mman.h> #include <sys/prctl.h> #define PUD_SIZE (1UL << 30) #define PMD_SIZE (1UL << 21) #define NR_PUD 130000 int main(void) { char *addr = NULL; unsigned long i; prctl(PR_SET_THP_DISABLE); for (i = 0; i < NR_PUD ; i++) { addr = mmap(addr + PUD_SIZE, PUD_SIZE, PROT_WRITE|PROT_READ, MAP_ANONYMOUS|MAP_PRIVATE, -1, 0); if (addr == MAP_FAILED) { perror("mmap"); break; } *addr = 'x'; munmap(addr, PMD_SIZE); mmap(addr, PMD_SIZE, PROT_WRITE|PROT_READ, MAP_ANONYMOUS|MAP_PRIVATE|MAP_FIXED, -1, 0); if (addr == MAP_FAILED) perror("re-mmap"), exit(1); } printf("PID %d consumed %lu KiB in PMD page tables\n", getpid(), i * 4096 >> 10); return pause(); } The patch addresses the issue by account PMD tables to the process the same way we account PTE. The main place where PMD tables is accounted is __pmd_alloc() and free_pmd_range(). But there're few corner cases: - HugeTLB can share PMD page tables. The patch handles by accounting the table to all processes who share it. - x86 PAE pre-allocates few PMD tables on fork. - Architectures with FIRST_USER_ADDRESS > 0. We need to adjust sanity check on exit(2). Accounting only happens on configuration where PMD page table's level is present (PMD is not folded). As with nr_ptes we use per-mm counter. The counter value is used to calculate baseline for badness score by oom-killer. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reported-by: Dave Hansen <dave.hansen@linux.intel.com> Cc: Hugh Dickins <hughd@google.com> Reviewed-by: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Pavel Emelyanov <xemul@openvz.org> Cc: David Rientjes <rientjes@google.com> Tested-by: Sedat Dilek <sedat.dilek@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-11oom, PM: make OOM detection in the freezer path racelessMichal Hocko2-42/+11
Commit 5695be142e20 ("OOM, PM: OOM killed task shouldn't escape PM suspend") has left a race window when OOM killer manages to note_oom_kill after freeze_processes checks the counter. The race window is quite small and really unlikely and partial solution deemed sufficient at the time of submission. Tejun wasn't happy about this partial solution though and insisted on a full solution. That requires the full OOM and freezer's task freezing exclusion, though. This is done by this patch which introduces oom_sem RW lock and turns oom_killer_disable() into a full OOM barrier. oom_killer_disabled check is moved from the allocation path to the OOM level and we take oom_sem for reading for both the check and the whole OOM invocation. oom_killer_disable() takes oom_sem for writing so it waits for all currently running OOM killer invocations. Then it disable all the further OOMs by setting oom_killer_disabled and checks for any oom victims. Victims are counted via mark_tsk_oom_victim resp. unmark_oom_victim. The last victim wakes up all waiters enqueued by oom_killer_disable(). Therefore this function acts as the full OOM barrier. The page fault path is covered now as well although it was assumed to be safe before. As per Tejun, "We used to have freezing points deep in file system code which may be reacheable from page fault." so it would be better and more robust to not rely on freezing points here. Same applies to the memcg OOM killer. out_of_memory tells the caller whether the OOM was allowed to trigger and the callers are supposed to handle the situation. The page allocation path simply fails the allocation same as before. The page fault path will retry the fault (more on that later) and Sysrq OOM trigger will simply complain to the log. Normally there wouldn't be any unfrozen user tasks after try_to_freeze_tasks so the function will not block. But if there was an OOM killer racing with try_to_freeze_tasks and the OOM victim didn't finish yet then we have to wait for it. This should complete in a finite time, though, because - the victim cannot loop in the page fault handler (it would die on the way out from the exception) - it cannot loop in the page allocator because all the further allocation would fail and __GFP_NOFAIL allocations are not acceptable at this stage - it shouldn't be blocked on any locks held by frozen tasks (try_to_freeze expects lockless context) and kernel threads and work queues are not frozen yet Signed-off-by: Michal Hocko <mhocko@suse.cz> Suggested-by: Tejun Heo <tj@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Cong Wang <xiyou.wangcong@gmail.com> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-11PM: convert printk to pr_* equivalentMichal Hocko1-14/+15
While touching this area let's convert printk to pr_*. This also makes the printing of continuation lines done properly. Signed-off-by: Michal Hocko <mhocko@suse.cz> Acked-by: Tejun Heo <tj@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Cong Wang <xiyou.wangcong@gmail.com> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-11oom: add helpers for setting and clearing TIF_MEMDIEMichal Hocko1-1/+1
This patchset addresses a race which was described in the changelog for 5695be142e20 ("OOM, PM: OOM killed task shouldn't escape PM suspend"): : PM freezer relies on having all tasks frozen by the time devices are : getting frozen so that no task will touch them while they are getting : frozen. But OOM killer is allowed to kill an already frozen task in order : to handle OOM situtation. In order to protect from late wake ups OOM : killer is disabled after all tasks are frozen. This, however, still keeps : a window open when a killed task didn't manage to die by the time : freeze_processes finishes. The original patch hasn't closed the race window completely because that would require a more complex solution as it can be seen by this patchset. The primary motivation was to close the race condition between OOM killer and PM freezer _completely_. As Tejun pointed out, even though the race condition is unlikely the harder it would be to debug weird bugs deep in the PM freezer when the debugging options are reduced considerably. I can only speculate what might happen when a task is still runnable unexpectedly. On a plus side and as a side effect the oom enable/disable has a better (full barrier) semantic without polluting hot paths. I have tested the series in KVM with 100M RAM: - many small tasks (20M anon mmap) which are triggering OOM continually - s2ram which resumes automatically is triggered in a loop echo processors > /sys/power/pm_test while true do echo mem > /sys/power/state sleep 1s done - simple module which allocates and frees 20M in 8K chunks. If it sees freezing(current) then it tries another round of allocation before calling try_to_freeze - debugging messages of PM stages and OOM killer enable/disable/fail added and unmark_oom_victim is delayed by 1s after it clears TIF_MEMDIE and before it wakes up waiters. - rebased on top of the current mmotm which means some necessary updates in mm/oom_kill.c. mark_tsk_oom_victim is now called under task_lock but I think this should be OK because __thaw_task shouldn't interfere with any locking down wake_up_process. Oleg? As expected there are no OOM killed tasks after oom is disabled and allocations requested by the kernel thread are failing after all the tasks are frozen and OOM disabled. I wasn't able to catch a race where oom_killer_disable would really have to wait but I kinda expected the race is really unlikely. [ 242.609330] Killed process 2992 (mem_eater) total-vm:24412kB, anon-rss:2164kB, file-rss:4kB [ 243.628071] Unmarking 2992 OOM victim. oom_victims: 1 [ 243.636072] (elapsed 2.837 seconds) done. [ 243.641985] Trying to disable OOM killer [ 243.643032] Waiting for concurent OOM victims [ 243.644342] OOM killer disabled [ 243.645447] Freezing remaining freezable tasks ... (elapsed 0.005 seconds) done. [ 243.652983] Suspending console(s) (use no_console_suspend to debug) [ 243.903299] kmem_eater: page allocation failure: order:1, mode:0x204010 [...] [ 243.992600] PM: suspend of devices complete after 336.667 msecs [ 243.993264] PM: late suspend of devices complete after 0.660 msecs [ 243.994713] PM: noirq suspend of devices complete after 1.446 msecs [ 243.994717] ACPI: Preparing to enter system sleep state S3 [ 243.994795] PM: Saving platform NVS memory [ 243.994796] Disabling non-boot CPUs ... The first 2 patches are simple cleanups for OOM. They should go in regardless the rest IMO. Patches 3 and 4 are trivial printk -> pr_info conversion and they should go in ditto. The main patch is the last one and I would appreciate acks from Tejun and Rafael. I think the OOM part should be OK (except for __thaw_task vs. task_lock where a look from Oleg would appreciated) but I am not so sure I haven't screwed anything in the freezer code. I have found several surprises there. This patch (of 5): This patch is just a preparatory and it doesn't introduce any functional change. Note: I am utterly unhappy about lowmemory killer abusing TIF_MEMDIE just to wait for the oom victim and to prevent from new killing. This is just a side effect of the flag. The primary meaning is to give the oom victim access to the memory reserves and that shouldn't be necessary here. Signed-off-by: Michal Hocko <mhocko@suse.cz> Cc: Tejun Heo <tj@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Cong Wang <xiyou.wangcong@gmail.com> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-11rcu: Clear need_qs flag to prevent splatPaul E. McKenney1-0/+1
If the scheduling-clock interrupt sets the current tasks need_qs flag, but if the current CPU passes through a quiescent state in the meantime, then rcu_preempt_qs() will fail to clear the need_qs flag, which can fool RCU into thinking that additional rcu_read_unlock_special() processing is needed. This commit therefore clears the need_qs flag before checking for additional processing. For this problem to occur, we need rcu_preempt_data.passed_quiesce equal to true and current->rcu_read_unlock_special.b.need_qs also equal to true. This condition can occur as follows: 1. CPU 0 is aware of the current preemptible RCU grace period, but has not yet passed through a quiescent state. Among other things, this means that rcu_preempt_data.passed_quiesce is false. 2. Task A running on CPU 0 enters a preemptible RCU read-side critical section. 3. CPU 0 takes a scheduling-clock interrupt, which notices the RCU read-side critical section and the need for a quiescent state, and thus sets current->rcu_read_unlock_special.b.need_qs to true. 4. Task A is preempted, enters the scheduler, eventually invoking rcu_preempt_note_context_switch() which in turn invokes rcu_preempt_qs(). Because rcu_preempt_data.passed_quiesce is false, control enters the body of the "if" statement, which sets rcu_preempt_data.passed_quiesce to true. 5. At this point, CPU 0 takes an interrupt. The interrupt handler contains an RCU read-side critical section, and the rcu_read_unlock() notes that current->rcu_read_unlock_special is nonzero, and thus invokes rcu_read_unlock_special(). 6. Once in rcu_read_unlock_special(), the fact that current->rcu_read_unlock_special.b.need_qs is true becomes apparent, so rcu_read_unlock_special() invokes rcu_preempt_qs(). Recursively, given that we interrupted out of that same function in the preceding step. 7. Because rcu_preempt_data.passed_quiesce is now true, rcu_preempt_qs() does nothing, and simply returns. 8. Upon return to rcu_read_unlock_special(), it is noted that current->rcu_read_unlock_special is still nonzero (because the interrupted rcu_preempt_qs() had not yet gotten around to clearing current->rcu_read_unlock_special.b.need_qs). 9. Execution proceeds to the WARN_ON_ONCE(), which notes that we are in an interrupt handler and thus duly splats. The solution, as noted above, is to make rcu_read_unlock_special() clear out current->rcu_read_unlock_special.b.need_qs after calling rcu_preempt_qs(). The interrupted rcu_preempt_qs() will clear it again, but this is harmless. The worst that happens is that we clobber another attempt to set this field, but this is not a problem because we just got done reporting a quiescent state. Reported-by: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> [ paulmck: Fix embarrassing build bug noted by Sasha Levin. ] Tested-by: Sasha Levin <sasha.levin@oracle.com>
2015-02-11ring-buffer: Do not wake up a splice waiter when page is not fullSteven Rostedt (Red Hat)1-5/+35
When an application connects to the ring buffer via splice, it can only read full pages. Splice does not work with partial pages. If there is not enough data to fill a page, the splice command will either block or return -EAGAIN (if set to nonblock). Code was added where if the page is not full, to just sleep again. The problem is, it will get woken up again on the next event. That is, when something is written into the ring buffer, if there is a waiter it will wake it up. The waiter would then check the buffer, see that it still does not have enough data to fill a page and go back to sleep. To make matters worse, when the waiter goes back to sleep, it could cause another event, which would wake it back up again to see it doesn't have enough data and sleep again. This produces a tremendous overhead and fills the ring buffer with noise. For example, recording sched_switch on an idle system for 10 seconds produces 25,350,475 events!!! Create another wait queue for those waiters wanting full pages. When an event is written, it only wakes up waiters if there's a full page of data. It does not wake up the waiter if the page is not yet full. After this change, recording sched_switch on an idle system for 10 seconds produces only 800 events. Getting rid of 25,349,675 useless events (99.9969% of events!!), is something to take seriously. Cc: stable@vger.kernel.org # 3.16+ Cc: Rabin Vincent <rabin@rab.in> Fixes: e30f53aad220 "tracing: Do not busy wait in buffer splice" Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-02-11module: Replace over-engineered nested sleepPeter Zijlstra1-28/+8
Since the introduction of the nested sleep warning; we've established that the occasional sleep inside a wait_event() is fine. wait_event() loops are invariant wrt. spurious wakeups, and the occasional sleep has a similar effect on them. As long as its occasional its harmless. Therefore replace the 'correct' but verbose wait_woken() thing with a simple annotation to shut up the warning. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-02-11module: Annotate nested sleep in resolve_symbol()Peter Zijlstra1-0/+6
Because wait_event() loops are safe vs spurious wakeups we can allow the occasional sleep -- which ends up being very similar. Reported-by: Dave Jones <davej@codemonkey.org.uk> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Dave Jones <davej@codemonkey.org.uk> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-02-10Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-nextLinus Torvalds5-88/+123
Pull networking updates from David Miller: 1) More iov_iter conversion work from Al Viro. [ The "crypto: switch af_alg_make_sg() to iov_iter" commit was wrong, and this pull actually adds an extra commit on top of the branch I'm pulling to fix that up, so that the pre-merge state is ok. - Linus ] 2) Various optimizations to the ipv4 forwarding information base trie lookup implementation. From Alexander Duyck. 3) Remove sock_iocb altogether, from CHristoph Hellwig. 4) Allow congestion control algorithm selection via routing metrics. From Daniel Borkmann. 5) Make ipv4 uncached route list per-cpu, from Eric Dumazet. 6) Handle rfs hash collisions more gracefully, also from Eric Dumazet. 7) Add xmit_more support to r8169, e1000, and e1000e drivers. From Florian Westphal. 8) Transparent Ethernet Bridging support for GRO, from Jesse Gross. 9) Add BPF packet actions to packet scheduler, from Jiri Pirko. 10) Add support for uniqu flow IDs to openvswitch, from Joe Stringer. 11) New NetCP ethernet driver, from Muralidharan Karicheri and Wingman Kwok. 12) More sanely handle out-of-window dupacks, which can result in serious ACK storms. From Neal Cardwell. 13) Various rhashtable bug fixes and enhancements, from Herbert Xu, Patrick McHardy, and Thomas Graf. 14) Support xmit_more in be2net, from Sathya Perla. 15) Group Policy extensions for vxlan, from Thomas Graf. 16) Remove Checksum Offload support for vxlan, from Tom Herbert. 17) Like ipv4, support lockless transmit over ipv6 UDP sockets. From Vlad Yasevich. * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1494+1 commits) crypto: fix af_alg_make_sg() conversion to iov_iter ipv4: Namespecify TCP PMTU mechanism i40e: Fix for stats init function call in Rx setup tcp: don't include Fast Open option in SYN-ACK on pure SYN-data openvswitch: Only set TUNNEL_VXLAN_OPT if VXLAN-GBP metadata is set ipv6: Make __ipv6_select_ident static ipv6: Fix fragment id assignment on LE arches. bridge: Fix inability to add non-vlan fdb entry net: Mellanox: Delete unnecessary checks before the function call "vunmap" cxgb4: Add support in cxgb4 to get expansion rom version via ethtool ethtool: rename reserved1 memeber in ethtool_drvinfo for expansion ROM version net: dsa: Remove redundant phy_attach() IB/mlx4: Reset flow support for IB kernel ULPs IB/mlx4: Always use the correct port for mirrored multicast attachments net/bonding: Fix potential bad memory access during bonding events tipc: remove tipc_snprintf tipc: nl compat add noop and remove legacy nl framework tipc: convert legacy nl stats show to nl compat tipc: convert legacy nl net id get to nl compat tipc: convert legacy nl net id set to nl compat ...