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2014-06-25Merge tag 'trace-fixes-v3.16-rc1-v2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing cleanups and fixes from Steven Rostedt: "This includes three patches from Oleg Nesterov. The first is a fix to a race condition that happens between enabling/disabling syscall tracepoints and new process creations (the check to go into the ptrace path for a process can be set when it shouldn't, or not set when it should). Not a major bug but one that should be fixed and even applied to stable. The other two patches are cleanup/fixes that are not that critical, but for an -rc1 release would be nice to have. They both deal with syscall tracepoints. It also includes a patch to introduce a new macro for the TRACE_EVENT() format called __field_struct(). Originally, __field() was used to record any variable into a trace event, but with the addition of setting the "is signed" attribute, the check causes anything but a primitive variable to fail to compile. That is, structs and unions can't be used as they once were. When the "is signed" check was introduce there were only primitive variables being recorded. But that will change soon and it was reported that __field() causes build failures. To solve the __field() issue, __field_struct() is introduced to allow trace_events to be able to record complex types too" * tag 'trace-fixes-v3.16-rc1-v2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: tracing: Add __field_struct macro for TRACE_EVENT() tracing: syscall_regfunc() should not skip kernel threads tracing: Change syscall_*regfunc() to check PF_KTHREAD and use for_each_process_thread() tracing: Fix syscall_*regfunc() vs copy_process() race
2014-06-23kernel/watchdog.c: print traces for all cpus on lockup detectionAaron Tomlin
A 'softlockup' is defined as a bug that causes the kernel to loop in kernel mode for more than a predefined period to time, without giving other tasks a chance to run. Currently, upon detection of this condition by the per-cpu watchdog task, debug information (including a stack trace) is sent to the system log. On some occasions, we have observed that the "victim" rather than the actual "culprit" (i.e. the owner/holder of the contended resource) is reported to the user. Often this information has proven to be insufficient to assist debugging efforts. To avoid loss of useful debug information, for architectures which support NMI, this patch makes it possible to improve soft lockup reporting. This is accomplished by issuing an NMI to each cpu to obtain a stack trace. If NMI is not supported we just revert back to the old method. A sysctl and boot-time parameter is available to toggle this feature. [dzickus@redhat.com: add CONFIG_SMP in certain areas] [akpm@linux-foundation.org: additional CONFIG_SMP=n optimisations] [mq@suse.cz: fix warning] Signed-off-by: Aaron Tomlin <atomlin@redhat.com> Signed-off-by: Don Zickus <dzickus@redhat.com> Cc: David S. Miller <davem@davemloft.net> Cc: Mateusz Guzik <mguzik@redhat.com> Cc: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Jan Moskyto Matejka <mq@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-23mm, pcp: allow restoring percpu_pagelist_fraction defaultDavid Rientjes
Oleg reports a division by zero error on zero-length write() to the percpu_pagelist_fraction sysctl: divide error: 0000 [#1] SMP DEBUG_PAGEALLOC CPU: 1 PID: 9142 Comm: badarea_io Not tainted 3.15.0-rc2-vm-nfs+ #19 Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 task: ffff8800d5aeb6e0 ti: ffff8800d87a2000 task.ti: ffff8800d87a2000 RIP: 0010: percpu_pagelist_fraction_sysctl_handler+0x84/0x120 RSP: 0018:ffff8800d87a3e78 EFLAGS: 00010246 RAX: 0000000000000f89 RBX: ffff88011f7fd000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000010 RBP: ffff8800d87a3e98 R08: ffffffff81d002c8 R09: ffff8800d87a3f50 R10: 000000000000000b R11: 0000000000000246 R12: 0000000000000060 R13: ffffffff81c3c3e0 R14: ffffffff81cfddf8 R15: ffff8801193b0800 FS: 00007f614f1e9740(0000) GS:ffff88011f440000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b CR2: 00007f614f1fa000 CR3: 00000000d9291000 CR4: 00000000000006e0 Call Trace: proc_sys_call_handler+0xb3/0xc0 proc_sys_write+0x14/0x20 vfs_write+0xba/0x1e0 SyS_write+0x46/0xb0 tracesys+0xe1/0xe6 However, if the percpu_pagelist_fraction sysctl is set by the user, it is also impossible to restore it to the kernel default since the user cannot write 0 to the sysctl. This patch allows the user to write 0 to restore the default behavior. It still requires a fraction equal to or larger than 8, however, as stated by the documentation for sanity. If a value in the range [1, 7] is written, the sysctl will return EINVAL. This successfully solves the divide by zero issue at the same time. Signed-off-by: David Rientjes <rientjes@google.com> Reported-by: Oleg Drokin <green@linuxhacker.ru> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-23kernel/watchdog.c: remove preemption restrictions when restarting lockup ↵Don Zickus
detector Peter Wu noticed the following splat on his machine when updating /proc/sys/kernel/watchdog_thresh: BUG: sleeping function called from invalid context at mm/slub.c:965 in_atomic(): 1, irqs_disabled(): 0, pid: 1, name: init 3 locks held by init/1: #0: (sb_writers#3){.+.+.+}, at: [<ffffffff8117b663>] vfs_write+0x143/0x180 #1: (watchdog_proc_mutex){+.+.+.}, at: [<ffffffff810e02d3>] proc_dowatchdog+0x33/0x110 #2: (cpu_hotplug.lock){.+.+.+}, at: [<ffffffff810589c2>] get_online_cpus+0x32/0x80 Preemption disabled at:[<ffffffff810e0384>] proc_dowatchdog+0xe4/0x110 CPU: 0 PID: 1 Comm: init Not tainted 3.16.0-rc1-testing #34 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 Call Trace: dump_stack+0x4e/0x7a __might_sleep+0x11d/0x190 kmem_cache_alloc_trace+0x4e/0x1e0 perf_event_alloc+0x55/0x440 perf_event_create_kernel_counter+0x26/0xe0 watchdog_nmi_enable+0x75/0x140 update_timers_all_cpus+0x53/0xa0 proc_dowatchdog+0xe4/0x110 proc_sys_call_handler+0xb3/0xc0 proc_sys_write+0x14/0x20 vfs_write+0xad/0x180 SyS_write+0x49/0xb0 system_call_fastpath+0x16/0x1b NMI watchdog: disabled (cpu0): hardware events not enabled What happened is after updating the watchdog_thresh, the lockup detector is restarted to utilize the new value. Part of this process involved disabling preemption. Once preemption was disabled, perf tried to allocate a new event (as part of the restart). This caused the above BUG_ON as you can't sleep with preemption disabled. The preemption restriction seemed agressive as we are not doing anything on that particular cpu, but with all the online cpus (which are protected by the get_online_cpus lock). Remove the restriction and the BUG_ON goes away. Signed-off-by: Don Zickus <dzickus@redhat.com> Acked-by: Michal Hocko <mhocko@suse.cz> Reported-by: Peter Wu <peter@lekensteyn.nl> Tested-by: Peter Wu <peter@lekensteyn.nl> Acked-by: David Rientjes <rientjes@google.com> Cc: <stable@vger.kernel.org> [3.13+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-23kexec: save PG_head_mask in VMCOREINFOPetr Tesarik
To allow filtering of huge pages, makedumpfile must be able to identify them in the dump. This can be done by checking the appropriate page flag, so communicate its value to makedumpfile through the VMCOREINFO interface. There's only one small catch. Depending on how many page flags are available on a given architecture, this bit can be called PG_head or PG_compound. I sent a similar patch back in 2012, but Eric Biederman did not like using an #ifdef. So, this time I'm adding a common symbol (PG_head_mask) instead. See https://lkml.org/lkml/2012/11/28/91 for the previous version. Signed-off-by: Petr Tesarik <ptesarik@suse.cz> Acked-by: Vivek Goyal <vgoyal@redhat.com> Cc: Eric Biederman <ebiederm@xmission.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Fengguang Wu <fengguang.wu@intel.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Shaohua Li <shli@kernel.org> Cc: Alexey Kardashevskiy <aik@ozlabs.ru> Cc: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-23CPU hotplug, smp: flush any pending IPI callbacks before CPU offlineSrivatsa S. Bhat
There is a race between the CPU offline code (within stop-machine) and the smp-call-function code, which can lead to getting IPIs on the outgoing CPU, *after* it has gone offline. Specifically, this can happen when using smp_call_function_single_async() to send the IPI, since this API allows sending asynchronous IPIs from IRQ disabled contexts. The exact race condition is described below. During CPU offline, in stop-machine, we don't enforce any rule in the _DISABLE_IRQ stage, regarding the order in which the outgoing CPU and the other CPUs disable their local interrupts. Due to this, we can encounter a situation in which an IPI is sent by one of the other CPUs to the outgoing CPU (while it is *still* online), but the outgoing CPU ends up noticing it only *after* it has gone offline. CPU 1 CPU 2 (Online CPU) (CPU going offline) Enter _PREPARE stage Enter _PREPARE stage Enter _DISABLE_IRQ stage = Got a device interrupt, and | Didn't notice the IPI the interrupt handler sent an | since interrupts were IPI to CPU 2 using | disabled on this CPU. smp_call_function_single_async() | = Enter _DISABLE_IRQ stage Enter _RUN stage Enter _RUN stage = Busy loop with interrupts | Invoke take_cpu_down() disabled. | and take CPU 2 offline = Enter _EXIT stage Enter _EXIT stage Re-enable interrupts Re-enable interrupts The pending IPI is noted immediately, but alas, the CPU is offline at this point. This of course, makes the smp-call-function IPI handler code running on CPU 2 unhappy and it complains about "receiving an IPI on an offline CPU". One real example of the scenario on CPU 1 is the block layer's complete-request call-path: __blk_complete_request() [interrupt-handler] raise_blk_irq() smp_call_function_single_async() However, if we look closely, the block layer does check that the target CPU is online before firing the IPI. So in this case, it is actually the unfortunate ordering/timing of events in the stop-machine phase that leads to receiving IPIs after the target CPU has gone offline. In reality, getting a late IPI on an offline CPU is not too bad by itself (this can happen even due to hardware latencies in IPI send-receive). It is a bug only if the target CPU really went offline without executing all the callbacks queued on its list. (Note that a CPU is free to execute its pending smp-call-function callbacks in a batch, without waiting for the corresponding IPIs to arrive for each one of those callbacks). So, fixing this issue can be broken up into two parts: 1. Ensure that a CPU goes offline only after executing all the callbacks queued on it. 2. Modify the warning condition in the smp-call-function IPI handler code such that it warns only if an offline CPU got an IPI *and* that CPU had gone offline with callbacks still pending in its queue. Achieving part 1 is straight-forward - just flush (execute) all the queued callbacks on the outgoing CPU in the CPU_DYING stage[1], including those callbacks for which the source CPU's IPIs might not have been received on the outgoing CPU yet. Once we do this, an IPI that arrives late on the CPU going offline (either due to the race mentioned above, or due to hardware latencies) will be completely harmless, since the outgoing CPU would have executed all the queued callbacks before going offline. Overall, this fix (parts 1 and 2 put together) additionally guarantees that we will see a warning only when the *IPI-sender code* is buggy - that is, if it queues the callback _after_ the target CPU has gone offline. [1]. The CPU_DYING part needs a little more explanation: by the time we execute the CPU_DYING notifier callbacks, the CPU would have already been marked offline. But we want to flush out the pending callbacks at this stage, ignoring the fact that the CPU is offline. So restructure the IPI handler code so that we can by-pass the "is-cpu-offline?" check in this particular case. (Of course, the right solution here is to fix CPU hotplug to mark the CPU offline _after_ invoking the CPU_DYING notifiers, but this requires a lot of audit to ensure that this change doesn't break any existing code; hence lets go with the solution proposed above until that is done). [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Suggested-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: Borislav Petkov <bp@suse.de> Cc: Christoph Hellwig <hch@infradead.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Gautham R Shenoy <ego@linux.vnet.ibm.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Mike Galbraith <mgalbraith@suse.de> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rafael J. Wysocki <rjw@rjwysocki.net> Cc: Rik van Riel <riel@redhat.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Tejun Heo <tj@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Tested-by: Sachin Kamat <sachin.kamat@samsung.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-21Merge branch 'perf-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf fixes from Ingo Molnar: "This is larger than usual: the main reason are the ARM symbol lookup speedups that came in late and were hard to resist. There's also a kprobes fix and various tooling fixes, plus the minimal re-enablement of the mmap2 support interface" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (36 commits) x86/kprobes: Fix build errors and blacklist context_track_user perf tests: Add test for closing dso objects on EMFILE error perf tests: Add test for caching dso file descriptors perf tests: Allow reuse of test_file function perf tests: Spawn child for each test perf tools: Add dso__data_* interface descriptons perf tools: Allow to close dso fd in case of open failure perf tools: Add file size check and factor dso__data_read_offset perf tools: Cache dso data file descriptor perf tools: Add global count of opened dso objects perf tools: Add global list of opened dso objects perf tools: Add data_fd into dso object perf tools: Separate dso data related variables perf tools: Cache register accesses for unwind processing perf record: Fix to honor user freq/interval properly perf timechart: Reflow documentation perf probe: Improve error messages in --line option perf probe: Improve an error message of perf probe --vars mode perf probe: Show error code and description in verbose mode perf probe: Improve error message for unknown member of data structure ...
2014-06-21Merge branch 'locking-urgent-for-linus.patch' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull rtmutex fixes from Thomas Gleixner: "Another three patches to make the rtmutex code more robust. That's the last urgent fallout from the big futex/rtmutex investigation" * 'locking-urgent-for-linus.patch' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: rtmutex: Plug slow unlock race rtmutex: Detect changes in the pi lock chain rtmutex: Handle deadlock detection smarter
2014-06-21tracing: syscall_regfunc() should not skip kernel threadsOleg Nesterov
syscall_regfunc() ignores the kernel threads because "it has no effect", see cc3b13c1 "Don't trace kernel thread syscalls" which added this check. However, this means that a user-space task spawned by call_usermodehelper() will run without TIF_SYSCALL_TRACEPOINT if sys_tracepoint_refcount != 0. Remove this check. The unnecessary report from ret_from_fork path mentioned by cc3b13c1 is no longer possible, see See commit fb45550d76bb5 "make sure that kernel_thread() callbacks call do_exit() themselves". A kernel_thread() callback can only return and take the int_ret_from_sys_call path after do_execve() succeeds, otherwise the kernel will crash. But in this case it is no longer a kernel thread and thus is needs TIF_SYSCALL_TRACEPOINT. Link: http://lkml.kernel.org/p/20140413185938.GD20668@redhat.com Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-06-21tracing: Change syscall_*regfunc() to check PF_KTHREAD and use ↵Oleg Nesterov
for_each_process_thread() 1. Remove _irqsafe from syscall_regfunc/syscall_unregfunc, read_lock(tasklist) doesn't need to disable irqs. 2. Change this code to avoid the deprecated do_each_thread() and use for_each_process_thread() (stolen from the patch from Frederic). 3. Change syscall_regfunc() to check PF_KTHREAD to skip the kernel threads, ->mm != NULL is the common mistake. Note: probably this check should be simply removed, needs another patch. [fweisbec@gmail.com: s/do_each_thread/for_each_process_thread/] Link: http://lkml.kernel.org/p/20140413185918.GC20668@redhat.com Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-06-21tracing: Fix syscall_*regfunc() vs copy_process() raceOleg Nesterov
syscall_regfunc() and syscall_unregfunc() should set/clear TIF_SYSCALL_TRACEPOINT system-wide, but do_each_thread() can race with copy_process() and miss the new child which was not added to the process/thread lists yet. Change copy_process() to update the child's TIF_SYSCALL_TRACEPOINT under tasklist. Link: http://lkml.kernel.org/p/20140413185854.GB20668@redhat.com Cc: stable@vger.kernel.org # 2.6.33 Fixes: a871bd33a6c0 "tracing: Add syscall tracepoints" Acked-by: Frederic Weisbecker <fweisbec@gmail.com> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-06-19Merge tag 'pm+acpi-3.16-rc2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull ACPI and power management fixes from Rafael Wysocki: "These are fixes mostly (ia64 regression related to the ACPI enumeration of devices, cpufreq regressions, fix for I2C controllers included in Intel SoCs, mvebu cpuidle driver fix related to sysfs) plus additional kernel command line arguments from Kees to make it possible to build kernel images with hibernation and the kernel address space randomization included simultaneously, a new ACPI battery driver quirk for a system with a broken BIOS and a couple of ACPI core cleanups. Specifics: - Fix for an ia64 regression introduced during the 3.11 cycle by a commit that modified the hardware initialization ordering and made device discovery fail on some systems. - Fix for a build problem on systems where the cpufreq-cpu0 driver is built-in and the cpu-thermal driver is modular from Arnd Bergmann. - Fix for a recently introduced computational mistake in the intel_pstate driver that leads to excessive rounding errors from Doug Smythies. - Fix for a failure code path in cpufreq_update_policy() that fails to unlock the locks acquired previously from Aaron Plattner. - Fix for the cpuidle mvebu driver to use shorter state names which will prevent the sysfs interface from returning mangled strings. From Gregory Clement. - ACPI LPSS driver fix to make sure that the I2C controllers included in BayTrail SoCs are not held in the reset state while they are being probed from Mika Westerberg. - New kernel command line arguments making it possible to build kernel images with hibernation and kASLR included at the same time and to select which of them will be used via the command line (they are still functionally mutually exclusive, though). From Kees Cook. - ACPI battery driver quirk for Acer Aspire V5-573G that fails to send battery status change notifications timely from Alexander Mezin. - Two ACPI core cleanups from Christoph Jaeger and Fabian Frederick" * tag 'pm+acpi-3.16-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: cpuidle: mvebu: Fix the name of the states cpufreq: unlock when failing cpufreq_update_policy() intel_pstate: Correct rounding in busy calculation ACPI: use kstrto*() instead of simple_strto*() ACPI / processor replace __attribute__((packed)) by __packed ACPI / battery: add quirk for Acer Aspire V5-573G ACPI / battery: use callback for setting up quirks ACPI / LPSS: Take I2C host controllers out of reset x86, kaslr: boot-time selectable with hibernation PM / hibernate: introduce "nohibernate" boot parameter cpufreq: cpufreq-cpu0: fix CPU_THERMAL dependency ACPI / ia64 / sba_iommu: Restore the working initialization ordering
2014-06-19Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-nextLinus Torvalds
Pull sparc fixes from David Miller: "Sparc sparse fixes from Sam Ravnborg" * git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-next: (67 commits) sparc64: fix sparse warnings in int_64.c sparc64: fix sparse warning in ftrace.c sparc64: fix sparse warning in kprobes.c sparc64: fix sparse warning in kgdb_64.c sparc64: fix sparse warnings in compat_audit.c sparc64: fix sparse warnings in init_64.c sparc64: fix sparse warnings in aes_glue.c sparc: fix sparse warnings in smp_32.c + smp_64.c sparc64: fix sparse warnings in perf_event.c sparc64: fix sparse warnings in kprobes.c sparc64: fix sparse warning in tsb.c sparc64: clean up compat_sigset_t.seta handling sparc64: fix sparse "Should it be static?" warnings in signal32.c sparc64: fix sparse warnings in sys_sparc32.c sparc64: fix sparse warning in pci.c sparc64: fix sparse warnings in smp_64.c sparc64: fix sparse warning in prom_64.c sparc64: fix sparse warning in btext.c sparc64: fix sparse warnings in sys_sparc_64.c + unaligned_64.c sparc64: fix sparse warning in process_64.c ... Conflicts: arch/sparc/include/asm/pgtable_64.h
2014-06-16x86, kaslr: boot-time selectable with hibernationKees Cook
Changes kASLR from being compile-time selectable (blocked by CONFIG_HIBERNATION), to being boot-time selectable (with hibernation available by default) via the "kaslr" kernel command line. Signed-off-by: Kees Cook <keescook@chromium.org> Acked-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-06-16PM / hibernate: introduce "nohibernate" boot parameterKees Cook
To support using kernel features that are not compatible with hibernation, this creates the "nohibernate" kernel boot parameter to disable both hibernation and resume. This allows hibernation support to be a boot-time choice instead of only a compile-time choice. Signed-off-by: Kees Cook <keescook@chromium.org> Acked-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-06-16rtmutex: Plug slow unlock raceThomas Gleixner
When the rtmutex fast path is enabled the slow unlock function can create the following situation: spin_lock(foo->m->wait_lock); foo->m->owner = NULL; rt_mutex_lock(foo->m); <-- fast path free = atomic_dec_and_test(foo->refcnt); rt_mutex_unlock(foo->m); <-- fast path if (free) kfree(foo); spin_unlock(foo->m->wait_lock); <--- Use after free. Plug the race by changing the slow unlock to the following scheme: while (!rt_mutex_has_waiters(m)) { /* Clear the waiters bit in m->owner */ clear_rt_mutex_waiters(m); owner = rt_mutex_owner(m); spin_unlock(m->wait_lock); if (cmpxchg(m->owner, owner, 0) == owner) return; spin_lock(m->wait_lock); } So in case of a new waiter incoming while the owner tries the slow path unlock we have two situations: unlock(wait_lock); lock(wait_lock); cmpxchg(p, owner, 0) == owner mark_rt_mutex_waiters(lock); acquire(lock); Or: unlock(wait_lock); lock(wait_lock); mark_rt_mutex_waiters(lock); cmpxchg(p, owner, 0) != owner enqueue_waiter(); unlock(wait_lock); lock(wait_lock); wakeup_next waiter(); unlock(wait_lock); lock(wait_lock); acquire(lock); If the fast path is disabled, then the simple m->owner = NULL; unlock(m->wait_lock); is sufficient as all access to m->owner is serialized via m->wait_lock; Also document and clarify the wakeup_next_waiter function as suggested by Oleg Nesterov. Reported-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Steven Rostedt <rostedt@goodmis.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20140611183852.937945560@linutronix.de Cc: stable@vger.kernel.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2014-06-14Merge branch 'perf/core' into perf/urgent, to pick up the latest fixesIngo Molnar
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-06-14x86/kprobes: Fix build errors and blacklist context_track_userMasami Hiramatsu
This essentially reverts commit: ecd50f714c42 ("kprobes, x86: Call exception_enter after kprobes handled") since it causes build errors with CONFIG_CONTEXT_TRACKING and that has been made from misunderstandings; context_track_user_*() don't involve much in interrupt context, it just returns if in_interrupt() is true. Instead of changing the do_debug/int3(), this just adds context_track_user_*() to kprobes blacklist, since those are still can be called right before kprobes handles int3 and debug exceptions, and probing those will cause an infinite loop. Reported-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Borislav Petkov <bp@suse.de> Cc: Kees Cook <keescook@chromium.org> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Seiji Aguchi <seiji.aguchi@hds.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Kees Cook <keescook@chromium.org> Link: http://lkml.kernel.org/r/20140614064711.7865.45957.stgit@kbuild-fedora.novalocal Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-06-12Merge tag 'trace-3.16-2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing cleanups and bugfixes from Steven Rostedt: "One bug fix that goes back to 3.10. Accessing a non existent buffer if "possible cpus" is greater than actual CPUs (including offline CPUs). Namhyung Kim did some reviews of the patches I sent this merge window and found a memory leak and had a few clean ups" * tag 'trace-3.16-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: tracing: Fix check of ftrace_trace_arrays list_empty() check tracing: Fix leak of per cpu max data in instances tracing: Cleanup saved_cmdlines_size changes ring-buffer: Check if buffer exists before polling
2014-06-12Merge branch 'sched-core-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull more scheduler updates from Ingo Molnar: "Second round of scheduler changes: - try-to-wakeup and IPI reduction speedups, from Andy Lutomirski - continued power scheduling cleanups and refactorings, from Nicolas Pitre - misc fixes and enhancements" * 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/deadline: Delete extraneous extern for to_ratio() sched/idle: Optimize try-to-wake-up IPI sched/idle: Simplify wake_up_idle_cpu() sched/idle: Clear polling before descheduling the idle thread sched, trace: Add a tracepoint for IPI-less remote wakeups cpuidle: Set polling in poll_idle sched: Remove redundant assignment to "rt_rq" in update_curr_rt(...) sched: Rename capacity related flags sched: Final power vs. capacity cleanups sched: Remove remaining dubious usage of "power" sched: Let 'struct sched_group_power' care about CPU capacity sched/fair: Disambiguate existing/remaining "capacity" usage sched/fair: Change "has_capacity" to "has_free_capacity" sched/fair: Remove "power" from 'struct numa_stats' sched: Fix signedness bug in yield_to() sched/fair: Use time_after() in record_wakee() sched/balancing: Reduce the rate of needless idle load balancing sched/fair: Fix unlocked reads of some cfs_b->quota/period
2014-06-12Merge branch 'perf-core-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull more perf updates from Ingo Molnar: "A second round of perf updates: - wide reaching kprobes sanitization and robustization, with the hope of fixing all 'probe this function crashes the kernel' bugs, by Masami Hiramatsu. - uprobes updates from Oleg Nesterov: tmpfs support, corner case fixes and robustization work. - perf tooling updates and fixes from Jiri Olsa, Namhyung Ki, Arnaldo et al: * Add support to accumulate hist periods (Namhyung Kim) * various fixes, refactorings and enhancements" * 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (101 commits) perf: Differentiate exec() and non-exec() comm events perf: Fix perf_event_comm() vs. exec() assumption uprobes/x86: Rename arch_uprobe->def to ->defparam, minor comment updates perf/documentation: Add description for conditional branch filter perf/x86: Add conditional branch filtering support perf/tool: Add conditional branch filter 'cond' to perf record perf: Add new conditional branch filter 'PERF_SAMPLE_BRANCH_COND' uprobes: Teach copy_insn() to support tmpfs uprobes: Shift ->readpage check from __copy_insn() to uprobe_register() perf/x86: Use common PMU interrupt disabled code perf/ARM: Use common PMU interrupt disabled code perf: Disable sampled events if no PMU interrupt perf: Fix use after free in perf_remove_from_context() perf tools: Fix 'make help' message error perf record: Fix poll return value propagation perf tools: Move elide bool into perf_hpp_fmt struct perf tools: Remove elide setup for SORT_MODE__MEMORY mode perf tools: Fix "==" into "=" in ui_browser__warning assignment perf tools: Allow overriding sysfs and proc finding with env var perf tools: Consider header files outside perf directory in tags target ...
2014-06-12Merge branch 'locking-core-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull more locking changes from Ingo Molnar: "This is the second round of locking tree updates for v3.16, offering large system scalability improvements: - optimistic spinning for rwsems, from Davidlohr Bueso. - 'qrwlocks' core code and x86 enablement, from Waiman Long and PeterZ" * 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86, locking/rwlocks: Enable qrwlocks on x86 locking/rwlocks: Introduce 'qrwlocks' - fair, queued rwlocks locking/mutexes: Documentation update/rewrite locking/rwsem: Fix checkpatch.pl warnings locking/rwsem: Fix warnings for CONFIG_RWSEM_GENERIC_SPINLOCK locking/rwsem: Support optimistic spinning
2014-06-12Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-nextLinus Torvalds
Pull networking updates from David Miller: 1) Seccomp BPF filters can now be JIT'd, from Alexei Starovoitov. 2) Multiqueue support in xen-netback and xen-netfront, from Andrew J Benniston. 3) Allow tweaking of aggregation settings in cdc_ncm driver, from Bjørn Mork. 4) BPF now has a "random" opcode, from Chema Gonzalez. 5) Add more BPF documentation and improve test framework, from Daniel Borkmann. 6) Support TCP fastopen over ipv6, from Daniel Lee. 7) Add software TSO helper functions and use them to support software TSO in mvneta and mv643xx_eth drivers. From Ezequiel Garcia. 8) Support software TSO in fec driver too, from Nimrod Andy. 9) Add Broadcom SYSTEMPORT driver, from Florian Fainelli. 10) Handle broadcasts more gracefully over macvlan when there are large numbers of interfaces configured, from Herbert Xu. 11) Allow more control over fwmark used for non-socket based responses, from Lorenzo Colitti. 12) Do TCP congestion window limiting based upon measurements, from Neal Cardwell. 13) Support busy polling in SCTP, from Neal Horman. 14) Allow RSS key to be configured via ethtool, from Venkata Duvvuru. 15) Bridge promisc mode handling improvements from Vlad Yasevich. 16) Don't use inetpeer entries to implement ID generation any more, it performs poorly, from Eric Dumazet. * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1522 commits) rtnetlink: fix userspace API breakage for iproute2 < v3.9.0 tcp: fixing TLP's FIN recovery net: fec: Add software TSO support net: fec: Add Scatter/gather support net: fec: Increase buffer descriptor entry number net: fec: Factorize feature setting net: fec: Enable IP header hardware checksum net: fec: Factorize the .xmit transmit function bridge: fix compile error when compiling without IPv6 support bridge: fix smatch warning / potential null pointer dereference via-rhine: fix full-duplex with autoneg disable bnx2x: Enlarge the dorq threshold for VFs bnx2x: Check for UNDI in uncommon branch bnx2x: Fix 1G-baseT link bnx2x: Fix link for KR with swapped polarity lane sctp: Fix sk_ack_backlog wrap-around problem net/core: Add VF link state control policy net/fsl: xgmac_mdio is dependent on OF_MDIO net/fsl: Make xgmac_mdio read error message useful net_sched: drr: warn when qdisc is not work conserving ...
2014-06-12Merge tag 'pm+acpi-3.16-rc1-2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull more ACPI and power management updates from Rafael Wysocki: "These are fixups on top of the previous PM+ACPI pull request, regression fixes (ACPI hotplug, cpufreq ppc-corenet), other bug fixes (ACPI reset, cpufreq), new PM trace points for system suspend profiling and a copyright notice update. Specifics: - I didn't remember correctly that the Hans de Goede's ACPI video patches actually didn't flip the video.use_native_backlight default, although we had discussed that and decided to do that. Since I said we would do that in the previous PM+ACPI pull request, make that change for real now. - ACPI bus check notifications for PCI host bridges don't cause the bus below the host bridge to be checked for changes as they should because of a mistake in the ACPI-based PCI hotplug (ACPIPHP) subsystem that forgets to add hotplug contexts to PCI host bridge ACPI device objects. Create hotplug contexts for PCI host bridges too as appropriate. - Revert recent cpufreq commit related to the big.LITTLE cpufreq driver that breaks arm64 builds. - Fix for a regression in the ppc-corenet cpufreq driver introduced during the 3.15 cycle and causing the driver to use the remainder from do_div instead of the quotient. From Ed Swarthout. - Resets triggered by panic activate a BUG_ON() in vmalloc.c on systems where the ACPI reset register is located in memory address space. Fix from Randy Wright. - Fix for a problem with cpufreq governors that decisions made by them may be suboptimal due to the fact that deferrable timers are used by them for CPU load sampling. From Srivatsa S Bhat. - Fix for a problem with the Tegra cpufreq driver where the CPU frequency is temporarily switched to a "stable" level that is different from both the initial and target frequencies during transitions which causes udelay() to expire earlier than it should sometimes. From Viresh Kumar. - New trace points and rework of some existing trace points for system suspend/resume profiling from Todd Brandt. - Assorted cpufreq fixes and cleanups from Stratos Karafotis and Viresh Kumar. - Copyright notice update for suspend-and-cpuhotplug.txt from Srivatsa S Bhat" * tag 'pm+acpi-3.16-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: ACPI / hotplug / PCI: Add hotplug contexts to PCI host bridges PM / sleep: trace events for device PM callbacks cpufreq: cpufreq-cpu0: remove dependency on THERMAL and REGULATOR cpufreq: tegra: update comment for clarity cpufreq: intel_pstate: Remove duplicate CPU ID check cpufreq: Mark CPU0 driver with CPUFREQ_NEED_INITIAL_FREQ_CHECK flag PM / Documentation: Update copyright in suspend-and-cpuhotplug.txt cpufreq: governor: remove copy_prev_load from 'struct cpu_dbs_common_info' cpufreq: governor: Be friendly towards latency-sensitive bursty workloads PM / sleep: trace events for suspend/resume cpufreq: ppc-corenet-cpu-freq: do_div use quotient Revert "cpufreq: Enable big.LITTLE cpufreq driver on arm64" cpufreq: Tegra: implement intermediate frequency callbacks cpufreq: add support for intermediate (stable) frequencies ACPI / video: Change the default for video.use_native_backlight to 1 ACPI: Fix bug when ACPI reset register is implemented in system memory
2014-06-12Merge commit '3cf2f34' into sched/core, to fix build errorIngo Molnar
Fix this dependency on the locking tree's smp_mb*() API changes: kernel/sched/idle.c:247:3: error: implicit declaration of function ‘smp_mb__after_atomic’ [-Werror=implicit-function-declaration] Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-06-12Merge branch 'pm-sleep'Rafael J. Wysocki
* pm-sleep: PM / sleep: trace events for device PM callbacks PM / sleep: trace events for suspend/resume
2014-06-11Merge tag 'modules-next-for-linus' of ↵Linus Torvalds
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()
2014-06-10Merge branch 'akpm' (patches from Andrew Morton)Linus Torvalds
Merge leftovers from Andrew Morton: "A few leftovers: ocfs2, gcov, RTC" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: rtc: s5m: consolidate two device type switch statements rtc: s5m: add support for S2MPS14 RTC rtc: s5m: support different register layout rtc: s5m: use shorter time of register update rtc: s5m: remove undocumented time init on first boot mfd/rtc: sec/s5m: rename SEC* symbols to S5M gcov: add support for GCC 4.9 ocfs2/o2net: incorrect to terminate accepting connections loop upon rejecting an invalid one
2014-06-10gcov: add support for GCC 4.9Yuan Pengfei
This patch handles the gcov-related changes in GCC 4.9: A new counter (time profile) is added. The total number is 9 now. A new profile merge function __gcov_merge_time_profile is added. See gcc/gcov-io.h and libgcc/libgcov-merge.c For the first change, the layout of struct gcov_info is affected. For the second one, a dummy function is added to kernel/gcov/base.c similarly. Signed-off-by: Yuan Pengfei <coolypf@qq.com> Acked-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-10fs,userns: Change inode_capable to capable_wrt_inode_uidgidAndy Lutomirski
The kernel has no concept of capabilities with respect to inodes; inodes exist independently of namespaces. For example, inode_capable(inode, CAP_LINUX_IMMUTABLE) would be nonsense. This patch changes inode_capable to check for uid and gid mappings and renames it to capable_wrt_inode_uidgid, which should make it more obvious what it does. Fixes CVE-2014-4014. Cc: Theodore Ts'o <tytso@mit.edu> Cc: Serge Hallyn <serge.hallyn@ubuntu.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Dave Chinner <david@fromorbit.com> Cc: stable@vger.kernel.org Signed-off-by: Andy Lutomirski <luto@amacapital.net> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-10tracing: Fix check of ftrace_trace_arrays list_empty() checkSteven Rostedt (Red Hat)
The check that tests if ftrace_trace_arrays is empty in top_trace_array(), uses the .prev pointer: if (list_empty(ftrace_trace_arrays.prev)) instead of testing the variable itself: if (list_empty(&ftrace_trace_arrays)) Although it is technically correct, it is awkward and confusing. Use the proper method. Link: http://lkml.kernel.org/r/87oay1bas8.fsf@sejong.aot.lge.com Reported-by: Namhyung Kim <namhyung@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-06-10tracing: Fix leak of per cpu max data in instancesSteven Rostedt (Red Hat)
The freeing of an instance, if max data is configured, there will be per cpu data structures created. But these are not freed when the instance is deleted, which causes a memory leak. A new helper function is added that frees the individual buffers within a trace array, instead of duplicating the code. This way changes made for one are applied to the other (normal buffer vs max buffer). Link: http://lkml.kernel.org/r/87k38pbake.fsf@sejong.aot.lge.com Reported-by: Namhyung Kim <namhyung@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-06-10auditsc: audit_krule mask accesses need bounds checkingAndy Lutomirski
Fixes an easy DoS and possible information disclosure. This does nothing about the broken state of x32 auditing. eparis: If the admin has enabled auditd and has specifically loaded audit rules. This bug has been around since before git. Wow... Cc: stable@vger.kernel.org Signed-off-by: Andy Lutomirski <luto@amacapital.net> Signed-off-by: Eric Paris <eparis@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-10tracing: Cleanup saved_cmdlines_size changesNamhyung Kim
The recent addition of saved_cmdlines_size file had some remaining (minor - mostly coding style) issues. Fix them by passing pointer name to sizeof() and using scnprintf(). Link: http://lkml.kernel.org/p/1402384295-23680-1-git-send-email-namhyung@kernel.org Cc: Namhyung Kim <namhyung.kim@lge.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Yoshihiro YUNOMAE <yoshihiro.yunomae.ez@hitachi.com> Signed-off-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-06-10ring-buffer: Check if buffer exists before pollingSteven Rostedt (Red Hat)
The per_cpu buffers are created one per possible CPU. But these do not mean that those CPUs are online, nor do they even exist. With the addition of the ring buffer polling, it assumes that the caller polls on an existing buffer. But this is not the case if the user reads trace_pipe from a CPU that does not exist, and this causes the kernel to crash. Simple fix is to check the cpu against buffer bitmask against to see if the buffer was allocated or not and return -ENODEV if it is not. More updates were done to pass the -ENODEV back up to userspace. Link: http://lkml.kernel.org/r/5393DB61.6060707@oracle.com Reported-by: Sasha Levin <sasha.levin@oracle.com> Cc: stable@vger.kernel.org # 3.10+ Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-06-09Merge tag 'trace-3.16' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing updates from Steven Rostedt: "Lots of tweaks, small fixes, optimizations, and some helper functions to help out the rest of the kernel to ease their use of trace events. The big change for this release is the allowing of other tracers, such as the latency tracers, to be used in the trace instances and allow for function or function graph tracing to be in the top level simultaneously" * tag 'trace-3.16' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (44 commits) tracing: Fix memory leak on instance deletion tracing: Fix leak of ring buffer data when new instances creation fails tracing/kprobes: Avoid self tests if tracing is disabled on boot up tracing: Return error if ftrace_trace_arrays list is empty tracing: Only calculate stats of tracepoint benchmarks for 2^32 times tracing: Convert stddev into u64 in tracepoint benchmark tracing: Introduce saved_cmdlines_size file tracing: Add __get_dynamic_array_len() macro for trace events tracing: Remove unused variable in trace_benchmark tracing: Eliminate double free on failure of allocation on boot up ftrace/x86: Call text_ip_addr() instead of the duplicated code tracing: Print max callstack on stacktrace bug tracing: Move locking of trace_cmdline_lock into start/stop seq calls tracing: Try again for saved cmdline if failed due to locking tracing: Have saved_cmdlines use the seq_read infrastructure tracing: Add tracepoint benchmark tracepoint tracing: Print nasty banner when trace_printk() is in use tracing: Add funcgraph_tail option to print function name after closing braces tracing: Eliminate duplicate TRACE_GRAPH_PRINT_xx defines tracing: Add __bitmask() macro to trace events to cpumasks and other bitmasks ...
2014-06-09Merge branch 'for-3.16' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup Pull cgroup updates from Tejun Heo: "A lot of activities on cgroup side. Heavy restructuring including locking simplification took place to improve the code base and enable implementation of the unified hierarchy, which currently exists behind a __DEVEL__ mount option. The core support is mostly complete but individual controllers need further work. To explain the design and rationales of the the unified hierarchy Documentation/cgroups/unified-hierarchy.txt is added. Another notable change is css (cgroup_subsys_state - what each controller uses to identify and interact with a cgroup) iteration update. This is part of continuing updates on css object lifetime and visibility. cgroup started with reference count draining on removal way back and is now reaching a point where csses behave and are iterated like normal refcnted objects albeit with some complexities to allow distinguishing the state where they're being deleted. The css iteration update isn't taken advantage of yet but is planned to be used to simplify memcg significantly" * 'for-3.16' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: (77 commits) cgroup: disallow disabled controllers on the default hierarchy cgroup: don't destroy the default root cgroup: disallow debug controller on the default hierarchy cgroup: clean up MAINTAINERS entries cgroup: implement css_tryget() device_cgroup: use css_has_online_children() instead of has_children() cgroup: convert cgroup_has_live_children() into css_has_online_children() cgroup: use CSS_ONLINE instead of CGRP_DEAD cgroup: iterate cgroup_subsys_states directly cgroup: introduce CSS_RELEASED and reduce css iteration fallback window cgroup: move cgroup->serial_nr into cgroup_subsys_state cgroup: link all cgroup_subsys_states in their sibling lists cgroup: move cgroup->sibling and ->children into cgroup_subsys_state cgroup: remove cgroup->parent device_cgroup: remove direct access to cgroup->children memcg: update memcg_has_children() to use css_next_child() memcg: remove tasks/children test from mem_cgroup_force_empty() cgroup: remove css_parent() cgroup: skip refcnting on normal root csses and cgrp_dfl_root self css cgroup: use cgroup->self.refcnt for cgroup refcnting ...
2014-06-09Merge branch 'for-3.16' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wqLinus Torvalds
Pull workqueue updates from Tejun Heo: "Lai simplified worker destruction path and internal workqueue locking and there are some other minor changes. Except for the removal of some long-deprecated interfaces which haven't had any in-kernel user for quite a while, there shouldn't be any difference to workqueue users" * 'for-3.16' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq: kernel/workqueue.c: pr_warning/pr_warn & printk/pr_info workqueue: remove the confusing POOL_FREEZING workqueue: rename first_worker() to first_idle_worker() workqueue: remove unused work_clear_pending() workqueue: remove unused WORK_CPU_END workqueue: declare system_highpri_wq workqueue: use generic attach/detach routine for rescuers workqueue: separate pool-attaching code out from create_worker() workqueue: rename manager_mutex to attach_mutex workqueue: narrow the protection range of manager_mutex workqueue: convert worker_idr to worker_ida workqueue: separate iteration role from worker_idr workqueue: destroy worker directly in the idle timeout handler workqueue: async worker destruction workqueue: destroy_worker() should destroy idle workers only workqueue: use manager lock only to protect worker_idr workqueue: Remove deprecated system_nrt[_freezable]_wq workqueue: Remove deprecated flush[_delayed]_work_sync() kernel/workqueue.c: pr_warning/pr_warn & printk/pr_info workqueue: simplify wq_update_unbound_numa() by jumping to use_dfl_pwq if the target cpumask equals wq's
2014-06-09Revert "perf: Disable PERF_RECORD_MMAP2 support"Don Zickus
This reverts commit 3090ffb5a2515990182f3f55b0688a7817325488. Re-enable the mmap2 interface as we will have a user soon. Since things have changed since perf disabled mmap2, small tweaks to the revert had to be done: o commit 9d4ecc88 forced (n!=8) to become (n<7) o a new libunwind test needed updating to use mmap2 interface Signed-off-by: Don Zickus <dzickus@redhat.com> Link: http://lkml.kernel.org/r/1401461382-209586-1-git-send-email-dzickus@redhat.com Signed-off-by: Jiri Olsa <jolsa@kernel.org>
2014-06-09perf: Pass protection and flags bits through mmap2 interfacePeter Zijlstra
The mmap2 interface was missing the protection and flags bits needed to accurately determine if a mmap memory area was shared or private and if it was readable or not. Signed-off-by: Peter Zijlstra <peterz@infradead.org> [tweaked patch to compile and wrote changelog] Signed-off-by: Don Zickus <dzickus@redhat.com> Link: http://lkml.kernel.org/r/1400526833-141779-2-git-send-email-dzickus@redhat.com Signed-off-by: Jiri Olsa <jolsa@kernel.org>
2014-06-08numa,sched: fix load_to_imbalanced logic inversionRik van Riel
This function is supposed to return true if the new load imbalance is worse than the old one. It didn't. I can only hope brown paper bags are in style. Now things converge much better on both the 4 node and 8 node systems. I am not sure why this did not seem to impact specjbb performance on the 4 node system, which is the system I have full-time access to. This bug was introduced recently, with commit e63da03639cc ("sched/numa: Allow task switch if load imbalance improves") Signed-off-by: Rik van Riel <riel@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-08Merge branch 'next' (accumulated 3.16 merge window patches) into masterLinus Torvalds
Now that 3.15 is released, this merges the 'next' branch into 'master', bringing us to the normal situation where my 'master' branch is the merge window. * accumulated work in next: (6809 commits) ufs: sb mutex merge + mutex_destroy powerpc: update comments for generic idle conversion cris: update comments for generic idle conversion idle: remove cpu_idle() forward declarations nbd: zero from and len fields in NBD_CMD_DISCONNECT. mm: convert some level-less printks to pr_* MAINTAINERS: adi-buildroot-devel is moderated MAINTAINERS: add linux-api for review of API/ABI changes mm/kmemleak-test.c: use pr_fmt for logging fs/dlm/debug_fs.c: replace seq_printf by seq_puts fs/dlm/lockspace.c: convert simple_str to kstr fs/dlm/config.c: convert simple_str to kstr mm: mark remap_file_pages() syscall as deprecated mm: memcontrol: remove unnecessary memcg argument from soft limit functions mm: memcontrol: clean up memcg zoneinfo lookup mm/memblock.c: call kmemleak directly from memblock_(alloc|free) mm/mempool.c: update the kmemleak stack trace for mempool allocations lib/radix-tree.c: update the kmemleak stack trace for radix tree allocations mm: introduce kmemleak_update_trace() mm/kmemleak.c: use %u to print ->checksum ...
2014-06-07rtmutex: Detect changes in the pi lock chainThomas Gleixner
When we walk the lock chain, we drop all locks after each step. So the lock chain can change under us before we reacquire the locks. That's harmless in principle as we just follow the wrong lock path. But it can lead to a false positive in the dead lock detection logic: T0 holds L0 T0 blocks on L1 held by T1 T1 blocks on L2 held by T2 T2 blocks on L3 held by T3 T4 blocks on L4 held by T4 Now we walk the chain lock T1 -> lock L2 -> adjust L2 -> unlock T1 -> lock T2 -> adjust T2 -> drop locks T2 times out and blocks on L0 Now we continue: lock T2 -> lock L0 -> deadlock detected, but it's not a deadlock at all. Brad tried to work around that in the deadlock detection logic itself, but the more I looked at it the less I liked it, because it's crystal ball magic after the fact. We actually can detect a chain change very simple: lock T1 -> lock L2 -> adjust L2 -> unlock T1 -> lock T2 -> adjust T2 -> next_lock = T2->pi_blocked_on->lock; drop locks T2 times out and blocks on L0 Now we continue: lock T2 -> if (next_lock != T2->pi_blocked_on->lock) return; So if we detect that T2 is now blocked on a different lock we stop the chain walk. That's also correct in the following scenario: lock T1 -> lock L2 -> adjust L2 -> unlock T1 -> lock T2 -> adjust T2 -> next_lock = T2->pi_blocked_on->lock; drop locks T3 times out and drops L3 T2 acquires L3 and blocks on L4 now Now we continue: lock T2 -> if (next_lock != T2->pi_blocked_on->lock) return; We don't have to follow up the chain at that point, because T2 propagated our priority up to T4 already. [ Folded a cleanup patch from peterz ] Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reported-by: Brad Mouring <bmouring@ni.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20140605152801.930031935@linutronix.de Cc: stable@vger.kernel.org
2014-06-07rtmutex: Handle deadlock detection smarterThomas Gleixner
Even in the case when deadlock detection is not requested by the caller, we can detect deadlocks. Right now the code stops the lock chain walk and keeps the waiter enqueued, even on itself. Silly not to yell when such a scenario is detected and to keep the waiter enqueued. Return -EDEADLK unconditionally and handle it at the call sites. The futex calls return -EDEADLK. The non futex ones dequeue the waiter, throw a warning and put the task into a schedule loop. Tagged for stable as it makes the code more robust. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Brad Mouring <bmouring@ni.com> Link: http://lkml.kernel.org/r/20140605152801.836501969@linutronix.de Cc: stable@vger.kernel.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2014-06-06tracing: Fix memory leak on instance deletionSteven Rostedt (Red Hat)
When an instance is created, it also gets a snapshot ring buffer allocated (with minimum of pages). But when it is deleted the snapshot buffer is not. There was a helper function added to match the allocation of these ring buffers to a way to free them, but it wasn't used by the deletion of an instance. Using that helper function solves this memory leak. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-06-06sysctl: convert use of typedef ctl_table to struct ctl_tableJoe Perches
This typedef is unnecessary and should just be removed. 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>
2014-06-06kernel/seccomp.c: kernel-doc warning fixFabian Frederick
+ fix small typo Signed-off-by: Fabian Frederick <fabf@skynet.be> Cc: "David S. Miller" <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-06ipc, kernel: clear whitespacePaul McQuade
trailing whitespace Signed-off-by: Paul McQuade <paulmcquad@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-06ipc, kernel: use Linux headersPaul McQuade
Use #include <linux/uaccess.h> instead of <asm/uaccess.h> Use #include <linux/types.h> instead of <asm/types.h> Signed-off-by: Paul McQuade <paulmcquad@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-06kernel/profile.c: use static const char instead of static charFabian Frederick
schedstr, sleepstr and kvmstr are only used in strcmp & strlen Signed-off-by: Fabian Frederick <fabf@skynet.be> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>