linux/kernel, branch v4.16-rc2

Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2018-02-18T20:38:40Z

Pull perf updates from Thomas Gleixner: "Perf tool updates and kprobe fixes: - perf_mmap overwrite mode fixes/overhaul, prep work to get 'perf top' using it, making it bearable to use it in large core count systems such as Knights Landing/Mill Intel systems (Kan Liang) - s/390 now uses syscall.tbl, just like x86-64 to generate the syscall table id -> string tables used by 'perf trace' (Hendrik Brueckner) - Use strtoull() instead of home grown function (Andy Shevchenko) - Synchronize kernel ABI headers, v4.16-rc1 (Ingo Molnar) - Document missing 'perf data --force' option (Sangwon Hong) - Add perf vendor JSON metrics for ARM Cortex-A53 Processor (William Cohen) - Improve error handling and error propagation of ftrace based kprobes so failures when installing kprobes are not silently ignored and create disfunctional tracepoints" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (27 commits) kprobes: Propagate error from disarm_kprobe_ftrace() kprobes: Propagate error from arm_kprobe_ftrace() Revert "tools include s390: Grab a copy of arch/s390/include/uapi/asm/unistd.h" perf s390: Rework system call table creation by using syscall.tbl perf s390: Grab a copy of arch/s390/kernel/syscall/syscall.tbl tools/headers: Synchronize kernel ABI headers, v4.16-rc1 perf test: Fix test trace+probe_libc_inet_pton.sh for s390x perf data: Document missing --force option perf tools: Substitute yet another strtoull() perf top: Check the latency of perf_top__mmap_read() perf top: Switch default mode to overwrite mode perf top: Remove lost events checking perf hists browser: Add parameter to disable lost event warning perf top: Add overwrite fall back perf evsel: Expose the perf_missing_features struct perf top: Check per-event overwrite term perf mmap: Discard legacy interface for mmap read perf test: Update mmap read functions for backward-ring-buffer test perf mmap: Introduce perf_mmap__read_event() perf mmap: Introduce perf_mmap__read_done() ...

Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2018-02-18T20:22:04Z

Pull irq updates from Thomas Gleixner: "A small set of updates mostly for irq chip drivers: - MIPS GIC fix for spurious, masked interrupts - fix for a subtle IPI bug in GICv3 - do not probe GICv3 ITSs that are marked as disabled - multi-MSI support for GICv2m - various small cleanups" * 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: irqdomain: Re-use DEFINE_SHOW_ATTRIBUTE() macro irqchip/bcm: Remove hashed address printing irqchip/gic-v2m: Add PCI Multi-MSI support irqchip/gic-v3: Ignore disabled ITS nodes irqchip/gic-v3: Use wmb() instead of smb_wmb() in gic_raise_softirq() irqchip/gic-v3: Change pr_debug message to pr_devel irqchip/mips-gic: Avoid spuriously handling masked interrupts

irqdomain: Re-use DEFINE_SHOW_ATTRIBUTE() macro

2018-02-16T14:22:34Z

...instead of open coding file operations followed by custom ->open() callbacks per each attribute. Signed-off-by: Andy Shevchenko Signed-off-by: Marc Zyngier

kprobes: Propagate error from disarm_kprobe_ftrace()

2018-02-16T08:12:58Z

Improve error handling when disarming ftrace-based kprobes. Like with arm_kprobe_ftrace(), propagate any errors from disarm_kprobe_ftrace() so that we do not disable/unregister kprobes that are still armed. In other words, unregister_kprobe() and disable_kprobe() should not report success if the kprobe could not be disarmed. disarm_all_kprobes() keeps its current behavior and attempts to disarm all kprobes. It returns the last encountered error and gives a warning if not all probes could be disarmed. This patch is based on Petr Mladek's original patchset (patches 2 and 3) back in 2015, which improved kprobes error handling, found here: https://lkml.org/lkml/2015/2/26/452 However, further work on this had been paused since then and the patches were not upstreamed. Based-on-patches-by: Petr Mladek Signed-off-by: Jessica Yu Acked-by: Masami Hiramatsu Cc: Ananth N Mavinakayanahalli Cc: Anil S Keshavamurthy Cc: David S . Miller Cc: Jiri Kosina Cc: Joe Lawrence Cc: Josh Poimboeuf Cc: Linus Torvalds Cc: Miroslav Benes Cc: Peter Zijlstra Cc: Petr Mladek Cc: Steven Rostedt Cc: Thomas Gleixner Cc: live-patching@vger.kernel.org Link: http://lkml.kernel.org/r/20180109235124.30886-3-jeyu@kernel.org Signed-off-by: Ingo Molnar

kprobes: Propagate error from arm_kprobe_ftrace()

2018-02-16T08:12:52Z

Improve error handling when arming ftrace-based kprobes. Specifically, if we fail to arm a ftrace-based kprobe, register_kprobe()/enable_kprobe() should report an error instead of success. Previously, this has lead to confusing situations where register_kprobe() would return 0 indicating success, but the kprobe would not be functional if ftrace registration during the kprobe arming process had failed. We should therefore take any errors returned by ftrace into account and propagate this error so that we do not register/enable kprobes that cannot be armed. This can happen if, for example, register_ftrace_function() finds an IPMODIFY conflict (since kprobe_ftrace_ops has this flag set) and returns an error. Such a conflict is possible since livepatches also set the IPMODIFY flag for their ftrace_ops. arm_all_kprobes() keeps its current behavior and attempts to arm all kprobes. It returns the last encountered error and gives a warning if not all probes could be armed. This patch is based on Petr Mladek's original patchset (patches 2 and 3) back in 2015, which improved kprobes error handling, found here: https://lkml.org/lkml/2015/2/26/452 However, further work on this had been paused since then and the patches were not upstreamed. Based-on-patches-by: Petr Mladek Signed-off-by: Jessica Yu Acked-by: Masami Hiramatsu Cc: Ananth N Mavinakayanahalli Cc: Anil S Keshavamurthy Cc: David S . Miller Cc: Jiri Kosina Cc: Joe Lawrence Cc: Josh Poimboeuf Cc: Linus Torvalds Cc: Miroslav Benes Cc: Peter Zijlstra Cc: Petr Mladek Cc: Steven Rostedt Cc: Thomas Gleixner Cc: live-patching@vger.kernel.org Link: http://lkml.kernel.org/r/20180109235124.30886-2-jeyu@kernel.org Signed-off-by: Ingo Molnar

Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2018-02-15T17:28:47Z

Pull scheduler fixes from Ingo Molnar: "Misc fixes: - fix rq->lock lockdep annotation bug - fix/improve update_curr_rt() and update_curr_dl() accounting - update documentation - remove unused macro" * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/cpufreq: Remove unused SUGOV_KTHREAD_PRIORITY macro sched/core: Fix DEBUG_SPINLOCK annotation for rq->lock sched/rt: Make update_curr_rt() more accurate sched/deadline: Make update_curr_dl() more accurate membarrier-sync-core: Document architecture support

Merge branch 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2018-02-15T17:05:26Z

Pull locking fixes from Ingo Molnar: "This contains two qspinlock fixes and three documentation and comment fixes" * 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: locking/semaphore: Update the file path in documentation locking/atomic/bitops: Document and clarify ordering semantics for failed test_and_{}_bit() locking/qspinlock: Ensure node->count is updated before initialising node locking/qspinlock: Ensure node is initialised before updating prev->next Documentation/locking/mutex-design: Update to reflect latest changes

locking/qspinlock: Ensure node->count is updated before initialising node

2018-02-13T13:50:14Z

When queuing on the qspinlock, the count field for the current CPU's head node is incremented. This needn't be atomic because locking in e.g. IRQ context is balanced and so an IRQ will return with node->count as it found it. However, the compiler could in theory reorder the initialisation of node[idx] before the increment of the head node->count, causing an IRQ to overwrite the initialised node and potentially corrupt the lock state. Avoid the potential for this harmful compiler reordering by placing a barrier() between the increment of the head node->count and the subsequent node initialisation. Signed-off-by: Will Deacon Acked-by: Peter Zijlstra (Intel) Cc: Linus Torvalds Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/1518528177-19169-3-git-send-email-will.deacon@arm.com Signed-off-by: Ingo Molnar

locking/qspinlock: Ensure node is initialised before updating prev->next

2018-02-13T13:50:14Z

When a locker ends up queuing on the qspinlock locking slowpath, we initialise the relevant mcs node and publish it indirectly by updating the tail portion of the lock word using xchg_tail. If we find that there was a pre-existing locker in the queue, we subsequently update their ->next field to point at our node so that we are notified when it's our turn to take the lock. This can be roughly illustrated as follows: /* Initialise the fields in node and encode a pointer to node in tail */ tail = initialise_node(node); /* * Exchange tail into the lockword using an atomic read-modify-write * operation with release semantics */ old = xchg_tail(lock, tail); /* If there was a pre-existing waiter ... */ if (old & _Q_TAIL_MASK) { prev = decode_tail(old); smp_read_barrier_depends(); /* ... then update their ->next field to point to node. WRITE_ONCE(prev->next, node); } The conditional update of prev->next therefore relies on the address dependency from the result of xchg_tail ensuring order against the prior initialisation of node. However, since the release semantics of the xchg_tail operation apply only to the write portion of the RmW, then this ordering is not guaranteed and it is possible for the CPU to return old before the writes to node have been published, consequently allowing us to point prev->next to an uninitialised node. This patch fixes the problem by making the update of prev->next a RELEASE operation, which also removes the reliance on dependency ordering. Signed-off-by: Will Deacon Acked-by: Peter Zijlstra (Intel) Cc: Linus Torvalds Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/1518528177-19169-2-git-send-email-will.deacon@arm.com Signed-off-by: Ingo Molnar

sched/cpufreq: Remove unused SUGOV_KTHREAD_PRIORITY macro

2018-02-13T12:04:03Z

Since schedutil kernel thread directly set priority to 0, the macro SUGOV_KTHREAD_PRIORITY is not used. So remove it. Signed-off-by: Leo Yan Acked-by: Viresh Kumar Acked-by: Daniel Lezcano Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Rafael J . Wysocki Cc: Thomas Gleixner Cc: Vikram Mulukutla Cc: Vincent Guittot Link: http://lkml.kernel.org/r/1518097702-9665-1-git-send-email-leo.yan@linaro.org Signed-off-by: Ingo Molnar