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2012-06-22Merge branch 'perf-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf updates from Ingo Molnar. * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: ftrace: Make all inline tags also include notrace perf: Use css_tryget() to avoid propping up css refcount perf tools: Fix synthesizing tracepoint names from the perf.data headers perf stat: Fix default output file perf tools: Fix endianity swapping for adds_features bitmask
2012-06-21Merge branch 'for-3.5-fixes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup Pull two cgroup fixes from Tejun Heo: "This containes two patches fixing a refcnt race bug during css_put(). Decrementing and checking the value weren't atomic and two tasks could think that they both pushed the counter to zero." * 'for-3.5-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: cgroups: Account for CSS_DEACT_BIAS in __css_put cgroup: make sure that decisions in __css_put are atomic
2012-06-20Merge tag 'driver-core-3.5-rc4' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core Pull driver core and printk fixes from Greg Kroah-Hartman: "Here are some fixes for 3.5-rc4 that resolve the kmsg problems that people have reported showing up after the printk and kmsg changes went into 3.5-rc1. There are also a smattering of other tiny fixes for the extcon and hyper-v drivers that people have reported. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>" * tag 'driver-core-3.5-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: extcon: max8997: Add missing kfree for info->edev in max8997_muic_remove() extcon: Set platform drvdata in gpio_extcon_probe() and fix irq leak extcon: Fix wrong index in max8997_extcon_cable[] kmsg - kmsg_dump() fix CONFIG_PRINTK=n compilation printk: return -EINVAL if the message len is bigger than the buf size printk: use mutex lock to stop syslog_seq from going wild kmsg - kmsg_dump() use iterator to receive log buffer content vme: change maintainer e-mail address Extcon: Don't try to create duplicate link names driver core: fixup reversed deferred probe order printk: Fix alignment of buf causing crash on ARM EABI Tools: hv: verify origin of netlink connector message
2012-06-20c/r: prctl: Move PR_GET_TID_ADDRESS to a proper placeCyrill Gorcunov
During merging of PR_GET_TID_ADDRESS patch the code has been misplaced (it happened to appear under PR_MCE_KILL) in result noone can use this option. Fix it by moving code snippet to a proper place. Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> Acked-by: Kees Cook <keescook@chromium.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Andrey Vagin <avagin@openvz.org> Cc: Serge Hallyn <serge.hallyn@canonical.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-06-20pidns: find_new_reaper() can no longer switch to init_pid_ns.child_reaperOleg Nesterov
find_new_reaper() changes pid_ns->child_reaper, see add0d4df ("pid_ns: zap_pid_ns_processes: fix the ->child_reaper changing"). The original reason has gone away after the previous patch, ->children list must be empty after zap_pid_ns_processes(). However now we can not switch to init_pid_ns.child_reaper. __unhash_process() relies on the "->child_reaper == parent" check, but this check does not work if the last exiting task is also the child reaper. As Eric sugested, we can change __unhash_process() to use the parent's pid_ns and remove this code. Also, with this change we can move detach_pid(PIDTYPE_PID) back, where it was before the previous fix. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Louis Rilling <louis.rilling@kerlabs.com> Cc: Mike Galbraith <efault@gmx.de> Acked-by: Pavel Emelyanov <xemul@parallels.com> Tested-by: Andrew Wagin <avagin@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-06-20pidns: guarantee that the pidns init will be the last pidns process reapedEric W. Biederman
Today we have a twofold bug. Sometimes release_task on pid == 1 in a pid namespace can run before other processes in a pid namespace have had release task called. With the result that pid_ns_release_proc can be called before the last proc_flus_task() is done using upid->ns->proc_mnt, resulting in the use of a stale pointer. This same set of circumstances can lead to waitpid(...) returning for a processes started with clone(CLONE_NEWPID) before the every process in the pid namespace has actually exited. To fix this modify zap_pid_ns_processess wait until all other processes in the pid namespace have exited, even EXIT_DEAD zombies. The delay_group_leader and related tests ensure that the thread gruop leader will be the last thread of a process group to be reaped, or to become EXIT_DEAD and self reap. With the change to zap_pid_ns_processes we get the guarantee that pid == 1 in a pid namespace will be the last task that release_task is called on. With pid == 1 being the last task to pass through release_task pid_ns_release_proc can no longer be called too early nor can wait return before all of the EXIT_DEAD tasks in a pid namespace have exited. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: Louis Rilling <louis.rilling@kerlabs.com> Cc: Mike Galbraith <efault@gmx.de> Acked-by: Pavel Emelyanov <xemul@parallels.com> Tested-by: Andrew Wagin <avagin@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-06-20mm: correctly synchronize rss-counters at exit/execKonstantin Khlebnikov
do_exit() and exec_mmap() call sync_mm_rss() before mm_release() does put_user(clear_child_tid) which can update task->rss_stat and thus make mm->rss_stat inconsistent. This triggers the "BUG:" printk in check_mm(). Let's fix this bug in the safest way, and optimize/cleanup this later. Reported-by: Markus Trippelsdorf <markus@trippelsdorf.de> Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Hugh Dickins <hughd@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-06-18cgroups: Account for CSS_DEACT_BIAS in __css_putSalman Qazi
When we fixed the race between atomic_dec and css_refcnt, we missed the fact that css_refcnt internally subtracts CSS_DEACT_BIAS to get the actual reference count. This can potentially cause a refcount leak if __css_put races with cgroup_clear_css_refs. Signed-off-by: Salman Qazi <sqazi@google.com> Acked-by: Li Zefan <lizefan@huawei.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2012-06-18perf: Use css_tryget() to avoid propping up css refcountSalman Qazi
An rmdir pushes css's ref count to zero. However, if the associated directory is open at the time, the dentry ref count is non-zero. If the fd for this directory is then passed into perf_event_open, it does a css_get(). This bounces the ref count back up from zero. This is a problem by itself. But what makes it turn into a crash is the fact that we end up doing an extra dput, since we perform a dput when css_put sees the ref count go down to zero. css_tryget() does not fall into that trap. So, we use that instead. Reproduction test-case for the bug: #include <unistd.h> #include <sys/types.h> #include <sys/stat.h> #include <fcntl.h> #include <linux/unistd.h> #include <linux/perf_event.h> #include <string.h> #include <errno.h> #include <stdio.h> #define PERF_FLAG_PID_CGROUP (1U << 2) int perf_event_open(struct perf_event_attr *hw_event_uptr, pid_t pid, int cpu, int group_fd, unsigned long flags) { return syscall(__NR_perf_event_open,hw_event_uptr, pid, cpu, group_fd, flags); } /* * Directly poke at the perf_event bug, since it's proving hard to repro * depending on where in the kernel tree. what moved? */ int main(int argc, char **argv) { int fd; struct perf_event_attr attr; memset(&attr, 0, sizeof(attr)); attr.exclude_kernel = 1; attr.size = sizeof(attr); mkdir("/dev/cgroup/perf_event/blah", 0777); fd = open("/dev/cgroup/perf_event/blah", O_RDONLY); perror("open"); rmdir("/dev/cgroup/perf_event/blah"); sleep(2); perf_event_open(&attr, fd, 0, -1, PERF_FLAG_PID_CGROUP); perror("perf_event_open"); close(fd); return 0; } Signed-off-by: Salman Qazi <sqazi@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Tejun Heo <tj@kernel.org> Link: http://lkml.kernel.org/r/20120614223108.1025.2503.stgit@dungbeetle.mtv.corp.google.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-06-16printk: return -EINVAL if the message len is bigger than the buf sizeYuanhan Liu
Just like what devkmsg_read() does, return -EINVAL if the message len is bigger than the buf size, or it will trigger a segfault error. Acked-by: Kay Sievers <kay@vrfy.org> Acked-by: Fengguang Wu <wfg@linux.intel.com> Signed-off-by: Yuanhan Liu <yuanhan.liu@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-06-16printk: use mutex lock to stop syslog_seq from going wildYuanhan Liu
Although syslog_seq and log_next_seq stuff are protected by logbuf_lock spin log, it's not enough. Say we have two processes A and B, and let syslog_seq = N, while log_next_seq = N + 1, and the two processes both come to syslog_print at almost the same time. And No matter which process get the spin lock first, it will increase syslog_seq by one, then release spin lock; thus later, another process increase syslog_seq by one again. In this case, syslog_seq is bigger than syslog_next_seq. And latter, it would make: wait_event_interruptiable(log_wait, syslog != log_next_seq) don't wait any more even there is no new write comes. Thus it introduce a infinite loop reading. I can easily see this kind of issue by the following steps: # cat /proc/kmsg # at meantime, I don't kill rsyslog # So they are the two processes. # xinit # I added drm.debug=6 in the kernel parameter line, # so that it will produce lots of message and let that # issue happen It's 100% reproducable on my side. And my disk will be filled up by /var/log/messages in a quite short time. So, introduce a mutex_lock to stop syslog_seq from going wild just like what devkmsg_read() does. It does fix this issue as expected. v2: use mutex_lock_interruptiable() instead (comments from Kay) Signed-off-by: Yuanhan Liu <yuanhan.liu@linux.intel.com> Reviewed-by: Fengguang Wu <fengguang.wu@intel.com> Acked-By: Kay Sievers <kay@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-06-15Merge 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. * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: watchdog: Quiet down the boot messages perf/x86: Fix broken LBR fixup code tracing: Have tracing_off() actually turn tracing off
2012-06-15Merge branch 'core-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull core updates (RCU and locking) from Ingo Molnar: "Most of the diffstat comes from the RCU slow boot regression fixes, but there's also a debuggability improvements/fixes." * 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: memblock: Document memblock_is_region_{memory,reserved}() rcu: Precompute RCU_FAST_NO_HZ timer offsets rcu: Move RCU_FAST_NO_HZ per-CPU variables to rcu_dynticks structure rcu: Update RCU_FAST_NO_HZ tracing for lazy callbacks rcu: RCU_FAST_NO_HZ detection of callback adoption spinlock: Indicate that a lockup is only suspected kdump: Execute kmsg_dump(KMSG_DUMP_PANIC) after smp_send_stop() panic: Make panic_on_oops configurable
2012-06-15kmsg - kmsg_dump() use iterator to receive log buffer contentKay Sievers
Provide an iterator to receive the log buffer content, and convert all kmsg_dump() users to it. The structured data in the kmsg buffer now contains binary data, which should no longer be copied verbatim to the kmsg_dump() users. The iterator should provide reliable access to the buffer data, and also supports proper log line-aware chunking of data while iterating. Signed-off-by: Kay Sievers <kay@vrfy.org> Tested-by: Tony Luck <tony.luck@intel.com> Reported-by: Anton Vorontsov <anton.vorontsov@linaro.org> Tested-by: Anton Vorontsov <anton.vorontsov@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-06-14watchdog: Quiet down the boot messagesDon Zickus
A bunch of bugzillas have complained how noisy the nmi_watchdog is during boot-up especially with its expected failure cases (like virt and bios resource contention). This is my attempt to quiet them down and keep it less confusing for the end user. What I did is print the message for cpu0 and save it for future comparisons. If future cpus have an identical message as cpu0, then don't print the redundant info. However, if a future cpu has a different message, happily print that loudly. Before the change, you would see something like: ..TIMER: vector=0x30 apic1=0 pin1=2 apic2=-1 pin2=-1 CPU0: Intel(R) Core(TM)2 Quad CPU Q9550 @ 2.83GHz stepping 0a Performance Events: PEBS fmt0+, Core2 events, Intel PMU driver. ... version: 2 ... bit width: 40 ... generic registers: 2 ... value mask: 000000ffffffffff ... max period: 000000007fffffff ... fixed-purpose events: 3 ... event mask: 0000000700000003 NMI watchdog enabled, takes one hw-pmu counter. Booting Node 0, Processors #1 NMI watchdog enabled, takes one hw-pmu counter. #2 NMI watchdog enabled, takes one hw-pmu counter. #3 Ok. NMI watchdog enabled, takes one hw-pmu counter. Brought up 4 CPUs Total of 4 processors activated (22607.24 BogoMIPS). After the change, it is simplified to: ..TIMER: vector=0x30 apic1=0 pin1=2 apic2=-1 pin2=-1 CPU0: Intel(R) Core(TM)2 Quad CPU Q9550 @ 2.83GHz stepping 0a Performance Events: PEBS fmt0+, Core2 events, Intel PMU driver. ... version: 2 ... bit width: 40 ... generic registers: 2 ... value mask: 000000ffffffffff ... max period: 000000007fffffff ... fixed-purpose events: 3 ... event mask: 0000000700000003 NMI watchdog: enabled on all CPUs, permanently consumes one hw-PMU counter. Booting Node 0, Processors #1 #2 #3 Ok. Brought up 4 CPUs V2: little changes based on Joe Perches' feedback V3: printk cleanup based on Ingo's feedback; checkpatch fix V4: keep printk as one long line V5: Ingo fix ups Reported-and-tested-by: Nathan Zimmer <nzimmer@sgi.com> Signed-off-by: Don Zickus <dzickus@redhat.com> Cc: nzimmer@sgi.com Cc: joe@perches.com Link: http://lkml.kernel.org/r/1339594548-17227-1-git-send-email-dzickus@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-06-12printk: Fix alignment of buf causing crash on ARM EABIAndrew Lunn
Commit 7ff9554bb578ba02166071d2d487b7fc7d860d62, printk: convert byte-buffer to variable-length record buffer, causes systems using EABI to crash very early in the boot cycle. The first entry in struct log is a u64, which for EABI must be 8 byte aligned. Make use of __alignof__() so the compiler to decide the alignment, but allow it to be overridden using CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS, for systems which can perform unaligned access and want to save a few bytes of space. Tested on Orion5x and Kirkwood. Signed-off-by: Andrew Lunn <andrew@lunn.ch> Tested-by: Stephen Warren <swarren@wwwdotorg.org> Acked-by: Stephen Warren <swarren@wwwdotorg.org> Acked-by: Kay Sievers <kay@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-06-11Merge branch 'rcu/urgent' of ↵Ingo Molnar
git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/urgent Merge RCU fixes from Paul E. McKenney: " This series has four patches, the major point of which is to eliminate some slowdowns (including boot-time slowdowns) resulting from some RCU_FAST_NO_HZ changes. The issue with the changes is that posting timers from the idle loop has no effect if the CPU has entered dyntick-idle mode because the CPU has already computed its wakeup time, and posting a timer does not cause it to be recomputed. The short-term fix is for RCU to precompute the timeout value so that the CPU's calculation is correct. " Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-06-08Merge branch 'sched-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler fixes from Ingo Molnar. * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched: Fix the relax_domain_level boot parameter sched: Validate assumptions in sched_init_numa() sched: Always initialize cpu-power sched: Fix domain iteration sched/rt: Fix lockdep annotation within find_lock_lowest_rq() sched/numa: Load balance between remote nodes sched/x86: Calculate booted cores after construction of sibling_mask
2012-06-08sched/fair: fix lots of kernel-doc warningsRandy Dunlap
Fix lots of new kernel-doc warnings in kernel/sched/fair.c: Warning(kernel/sched/fair.c:3625): No description found for parameter 'env' Warning(kernel/sched/fair.c:3625): Excess function parameter 'sd' description in 'update_sg_lb_stats' Warning(kernel/sched/fair.c:3735): No description found for parameter 'env' Warning(kernel/sched/fair.c:3735): Excess function parameter 'sd' description in 'update_sd_pick_busiest' Warning(kernel/sched/fair.c:3735): Excess function parameter 'this_cpu' description in 'update_sd_pick_busiest' .. more warnings Signed-off-by: Randy Dunlap <rdunlap@xenotime.net> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-06-08Merge 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: "A bit larger than what I'd wish for - half of it is due to hw driver updates to Intel Ivy-Bridge which info got recently released, cycles:pp should work there now too, amongst other things. (but we are generally making exceptions for hardware enablement of this type.) There are also callchain fixes in it - responding to mostly theoretical (but valid) concerns. The tooling side sports perf.data endianness/portability fixes which did not make it for the merge window - and various other fixes as well." * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (26 commits) perf/x86: Check user address explicitly in copy_from_user_nmi() perf/x86: Check if user fp is valid perf: Limit callchains to 127 perf/x86: Allow multiple stacks perf/x86: Update SNB PEBS constraints perf/x86: Enable/Add IvyBridge hardware support perf/x86: Implement cycles:p for SNB/IVB perf/x86: Fix Intel shared extra MSR allocation x86/decoder: Fix bsr/bsf/jmpe decoding with operand-size prefix perf: Remove duplicate invocation on perf_event_for_each perf uprobes: Remove unnecessary check before strlist__delete perf symbols: Check for valid dso before creating map perf evsel: Fix 32 bit values endianity swap for sample_id_all header perf session: Handle endianity swap on sample_id_all header data perf symbols: Handle different endians properly during symbol load perf evlist: Pass third argument to ioctl explicitly perf tools: Update ioctl documentation for PERF_IOC_FLAG_GROUP perf tools: Make --version show kernel version instead of pull req tag perf tools: Check if callchain is corrupted perf callchain: Make callchain cursors TLS ...
2012-06-08Merge branch 'timers-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull leap second timer fix from Thomas Gleixner. * 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: timekeeping: Fix CLOCK_MONOTONIC inconsistency during leapsecond
2012-06-08Merge branch 'tip/perf/urgent' of ↵Ingo Molnar
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace into perf/urgent Pull brown paper bag fix from Steve Rostedt. Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-06-08Revert "mm: correctly synchronize rss-counters at exit/exec"Linus Torvalds
This reverts commit 40af1bbdca47e5c8a2044039bb78ca8fd8b20f94. It's horribly and utterly broken for at least the following reasons: - calling sync_mm_rss() from mmput() is fundamentally wrong, because there's absolutely no reason to believe that the task that does the mmput() always does it on its own VM. Example: fork, ptrace, /proc - you name it. - calling it *after* having done mmdrop() on it is doubly insane, since the mm struct may well be gone now. - testing mm against NULL before you call it is insane too, since a NULL mm there would have caused oopses long before. .. and those are just the three bugs I found before I decided to give up looking for me and revert it asap. I should have caught it before I even took it, but I trusted Andrew too much. Cc: Konstantin Khlebnikov <khlebnikov@openvz.org> Cc: Markus Trippelsdorf <markus@trippelsdorf.de> Cc: Hugh Dickins <hughd@google.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-06-07mm: correctly synchronize rss-counters at exit/execKonstantin Khlebnikov
mm->rss_stat counters have per-task delta: task->rss_stat. Before changing task->mm pointer the kernel must flush this delta with sync_mm_rss(). do_exit() already calls sync_mm_rss() to flush the rss-counters before committing the rss statistics into task->signal->maxrss, taskstats, audit and other stuff. Unfortunately the kernel does this before calling mm_release(), which can call put_user() for processing task->clear_child_tid. So at this point we can trigger page-faults and task->rss_stat becomes non-zero again. As a result mm->rss_stat becomes inconsistent and check_mm() will print something like this: | BUG: Bad rss-counter state mm:ffff88020813c380 idx:1 val:-1 | BUG: Bad rss-counter state mm:ffff88020813c380 idx:2 val:1 This patch moves sync_mm_rss() into mm_release(), and moves mm_release() out of do_exit() and calls it earlier. After mm_release() there should be no pagefaults. [akpm@linux-foundation.org: tweak comment] Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org> Reported-by: Markus Trippelsdorf <markus@trippelsdorf.de> Cc: Hugh Dickins <hughd@google.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: <stable@vger.kernel.org> [3.4.x] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-06-07c/r: prctl: drop VMA flags test on PR_SET_MM_ stack data assignmentCyrill Gorcunov
In commit b76437579d13 ("procfs: mark thread stack correctly in proc/<pid>/maps") the stack allocated via clone() is marked in /proc/<pid>/maps as [stack:%d] thus it might be out of the former mm->start_stack/end_stack values (and even has some custom VMA flags set). So to be able to restore mm->start_stack/end_stack drop vma flags test, but still require the underlying VMA to exist. As always note this feature is under CONFIG_CHECKPOINT_RESTORE and requires CAP_SYS_RESOURCE to be granted. Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Oleg Nesterov <oleg@redhat.com> Acked-by: Kees Cook <keescook@chromium.org> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Serge Hallyn <serge.hallyn@canonical.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-06-07c/r: prctl: add ability to get clear_tid_addressCyrill Gorcunov
Zero is written at clear_tid_address when the process exits. This functionality is used by pthread_join(). We already have sys_set_tid_address() to change this address for the current task but there is no way to obtain it from user space. Without the ability to find this address and dump it we can't restore pthread'ed apps which call pthread_join() once they have been restored. This patch introduces the PR_GET_TID_ADDRESS prctl option which allows the current process to obtain own clear_tid_address. This feature is available iif CONFIG_CHECKPOINT_RESTORE is set. [akpm@linux-foundation.org: fix prctl numbering] Signed-off-by: Andrew Vagin <avagin@openvz.org> Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Pedro Alves <palves@redhat.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Tejun Heo <tj@kernel.org> Acked-by: Kees Cook <keescook@chromium.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-06-07c/r: prctl: add minimal address test to PR_SET_MMCyrill Gorcunov
Make sure the address being set is greater than mmap_min_addr (as suggested by Kees Cook). Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> Acked-by: Kees Cook <keescook@chromium.org> Cc: Serge Hallyn <serge.hallyn@canonical.com> Cc: Tejun Heo <tj@kernel.org> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-06-07c/r: prctl: update prctl_set_mm_exe_file() after mm->num_exe_file_vmas removalKonstantin Khlebnikov
A fix for commit b32dfe377102 ("c/r: prctl: add ability to set new mm_struct::exe_file"). After removing mm->num_exe_file_vmas kernel keeps mm->exe_file until final mmput(), it never becomes NULL while task is alive. We can check for other mapped files in mm instead of checking mm->num_exe_file_vmas, and mark mm with flag MMF_EXE_FILE_CHANGED in order to forbid second changing of mm->exe_file. Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org> Reviewed-by: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Matt Helsley <matthltc@us.ibm.com> Cc: Kees Cook <keescook@chromium.org> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Tejun Heo <tj@kernel.org> Cc: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-06-07rcu: Precompute RCU_FAST_NO_HZ timer offsetsPaul E. McKenney
When a CPU is entering dyntick-idle mode, tick_nohz_stop_sched_tick() calls rcu_needs_cpu() see if RCU needs that CPU, and, if not, computes the next wakeup time based on the timer wheels. Only later, when actually entering the idle loop, rcu_prepare_for_idle() will be invoked. In some cases, rcu_prepare_for_idle() will post timers to wake the CPU back up. But all for naught: The next wakeup time for the CPU has already been computed, and posting a timer afterwards does not force that wakeup time to be recomputed. This means that rcu_prepare_for_idle()'s have no effect. This is not a problem on a busy system because something else will wake up the CPU soon enough. However, on lightly loaded systems, the CPU might stay asleep for a considerable length of time. If that CPU has a callback that the rest of the system is waiting on, the system might run very slowly or (in theory) even hang. This commit avoids this problem by having rcu_needs_cpu() give tick_nohz_stop_sched_tick() an estimate of when RCU will need the CPU to wake back up, which tick_nohz_stop_sched_tick() takes into account when programming the CPU's wakeup time. An alternative approach is for rcu_prepare_for_idle() to use hrtimers instead of normal timers, but timers are much more efficient than are hrtimers for frequently and repeatedly posting and cancelling a given timer, which is exactly what RCU_FAST_NO_HZ does. Reported-by: Pascal Chapperon <pascal.chapperon@wanadoo.fr> Reported-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Tested-by: Heiko Carstens <heiko.carstens@de.ibm.com> Tested-by: Pascal Chapperon <pascal.chapperon@wanadoo.fr>
2012-06-07rcu: Move RCU_FAST_NO_HZ per-CPU variables to rcu_dynticks structurePaul E. McKenney
The RCU_FAST_NO_HZ code relies on a number of per-CPU variables. This works, but is hidden from someone scanning the data structures in rcutree.h. This commit therefore converts these per-CPU variables to fields in the per-CPU rcu_dynticks structures. Suggested-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Tested-by: Heiko Carstens <heiko.carstens@de.ibm.com> Tested-by: Pascal Chapperon <pascal.chapperon@wanadoo.fr>
2012-06-07rcu: Update RCU_FAST_NO_HZ tracing for lazy callbacksPaul E. McKenney
In the current code, a short dyntick-idle interval (where there is at least one non-lazy callback on the CPU) and a long dyntick-idle interval (where there are only lazy callbacks on the CPU) are traced identically, which can be less than helpful. This commit therefore emits different event traces in these two cases. Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Tested-by: Heiko Carstens <heiko.carstens@de.ibm.com> Tested-by: Pascal Chapperon <pascal.chapperon@wanadoo.fr>
2012-06-07rcu: RCU_FAST_NO_HZ detection of callback adoptionPaul E. McKenney
In the present implementations of CPU hotplug, the outgoing CPU is guaranteed to run its stop-machine process on the way out, which will guarantee that RCU_FAST_NO_HZ forces the CPU out of dyntick-idle mode. However, new versions of CPU hotplug might not work this way. This commit therefore removes this design constraint by explicitly notifying CPUs when they adopt non-lazy RCU callbacks. Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Tested-by: Heiko Carstens <heiko.carstens@de.ibm.com> Tested-by: Pascal Chapperon <pascal.chapperon@wanadoo.fr>
2012-06-07tracing: Have tracing_off() actually turn tracing offSteven Rostedt
A recent update to have tracing_on/off() only affect the ftrace ring buffers instead of all ring buffers had a cut and paste error. The tracing_off() did the exact same thing as tracing_on() and would not actually turn off tracing. Unfortunately, tracing_off() is more important to be working than tracing_on() as this is a key development tool, as it lets the developer turn off tracing as soon as a problem is discovered. It is also used by panic and oops code. This bug also breaks the 'echo func:traceoff > set_ftrace_filter' Cc: <stable@vger.kernel.org> # 3.4 Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2012-06-07cgroup: make sure that decisions in __css_put are atomicSalman Qazi
__css_put is using atomic_dec on the ref count, and then looking at the ref count to make decisions. This is prone to races, as someone else may decrement ref count between our decrement and our decision. Instead, we should base our decisions on the value that we decremented the ref count to. (This results in an actual race on Google's kernel which I haven't been able to reproduce on the upstream kernel. Having said that, it's still incorrect by inspection). Signed-off-by: Salman Qazi <sqazi@google.com> Acked-by: Li Zefan <lizefan@huawei.com> Signed-off-by: Tejun Heo <tj@kernel.org> Cc: stable@vger.kernel.org
2012-06-06sched: Fix the relax_domain_level boot parameterDimitri Sivanich
It does not get processed because sched_domain_level_max is 0 at the time that setup_relax_domain_level() is run. Simply accept the value as it is, as we don't know the value of sched_domain_level_max until sched domain construction is completed. Fix sched_relax_domain_level in cpuset. The build_sched_domain() routine calls the set_domain_attribute() routine prior to setting the sd->level, however, the set_domain_attribute() routine relies on the sd->level to decide whether idle load balancing will be off/on. Signed-off-by: Dimitri Sivanich <sivanich@sgi.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20120605184436.GA15668@sgi.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-06-06sched: Validate assumptions in sched_init_numa()Peter Zijlstra
Add some code to validate assumptions we're making and output warnings if they are not. If this trigger we want to know about it. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Alex Shi <lkml.alex@gmail.com> Link: http://lkml.kernel.org/n/tip-6uc3wk5s9udxtdl9cnku0vtt@git.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-06-06sched: Always initialize cpu-powerPeter Zijlstra
Often when we run into mis-shapen topologies the balance iteration fails to update the cpu power properly and we'll end up in /0 traps. Always initialize the cpu-power to a semi-sane value so that we can at least boot the machine, even if the load-balancer might not function correctly. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/n/tip-3lbhyj25sr169ha7z3qht5na@git.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-06-06sched: Fix domain iterationPeter Zijlstra
Weird topologies can lead to asymmetric domain setups. This needs further consideration since these setups are typically non-minimal too. For now, make it work by adding an extra mask selecting which CPUs are allowed to iterate up. The topology that triggered it is the one from David Rientjes: 10 20 20 30 20 10 20 20 20 20 10 20 30 20 20 10 resulting in boxes that wouldn't even boot. Reported-by: David Rientjes <rientjes@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/n/tip-3p86l9cuaqnxz7uxsojmz5rm@git.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-06-06sched/rt: Fix lockdep annotation within find_lock_lowest_rq()Peter Zijlstra
Roland Dreier reported spurious, hard to trigger lockdep warnings within the scheduler - without any real lockup. This bit gives us the right clue: > [89945.640512] [<ffffffff8103fa1a>] double_lock_balance+0x5a/0x90 > [89945.640568] [<ffffffff8104c546>] push_rt_task+0xc6/0x290 if you look at that code you'll find the double_lock_balance() in question is the one in find_lock_lowest_rq() [yay for inlining]. Now find_lock_lowest_rq() has a bug.. it fails to use double_unlock_balance() in one exit path, if this results in a retry in push_rt_task() we'll call double_lock_balance() again, at which point we'll run into said lockdep confusion. Reported-by: Roland Dreier <roland@kernel.org> Acked-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1337282386.4281.77.camel@twins Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-06-06sched/numa: Load balance between remote nodesAlex Shi
Commit cb83b629b ("sched/numa: Rewrite the CONFIG_NUMA sched domain support") removed the NODE sched domain and started checking if the node distance in SLIT table is farther than REMOTE_DISTANCE, if so, it will lose the load balance chance at exec/fork/wake_affine points. But actually, even the node distance is farther than REMOTE_DISTANCE. Modern CPUs also has QPI like connections, which ensures that memory access is not too slow between nodes. So the above change in behavior on NUMA machine causes a performance regression on various benchmarks: hackbench, tbench, netperf, oltp, etc. This patch will recover the scheduler behavior to old mode on all my Intel platforms: NHM EP/EX, WSM EP, SNB EP/EP4S, and thus fixes the perfromance regressions. (all of them just have 2 kinds distance, 10, 21) Signed-off-by: Alex Shi <alex.shi@intel.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1338965571-9812-1-git-send-email-alex.shi@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-06-06Merge branch 'core/debug' into core/urgentIngo Molnar
Merge two debugging patchlets that were waiting for preparatory commits to hit upstream. Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-06-06Merge tag 'perf-urgent-for-mingo' of ↵Ingo Molnar
git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/urgent Pull perf fixes from Arnaldo Carvalho de Melo: * Endianness fixes from Jiri Olsa * Fixes for make perf tarball * Fix for DSO name in perf script callchains, from David Ahern * Segfault fixes for perf top --callchain, from Namhyung Kim * Minor function result fixes from Srikar Dronamraju * Add missing 3rd ioctl parameter, from Namhyung Kim * Fix pager usage in minimal embedded systems, from Avik Sil Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-06-05Merge branch 'for-3.5-fixes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup Pull cgroup fix from Tejun Heo: "This fixes the possible premature superblock release on umount bug mentioned during v3.5-rc1 pull request. Originally, cgroup dentry destruction path assumed that cgroup dentry didn't have any reference left after cgroup removal thus put super during dentry removal. Now that there can be lingering dentry references, this led to super being put with live dentries. This patch fixes the problem by putting super ref on dentry release instead of removal." * 'for-3.5-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: cgroup: superblock can't be released with active dentries
2012-06-05Merge branch 'sched-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler fixes from Ingo Molnar. * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched: Remove NULL assignment of dattr_cur sched: Remove the last NULL entry from sched_feat_names sched: Make sched_feat_names const sched/rt: Fix SCHED_RR across cgroups sched: Move nr_cpus_allowed out of 'struct sched_rt_entity' sched: Make sure to not re-read variables after validation sched: Fix SD_OVERLAP sched: Don't try allocating memory from offline nodes sched/nohz: Fix rq->cpu_load calculations some more sched/x86: Use cpu_llc_shared_mask(cpu) for coregroup_mask
2012-06-04timekeeping: Fix CLOCK_MONOTONIC inconsistency during leapsecondJohn Stultz
Commit 6b43ae8a61 (ntp: Fix leap-second hrtimer livelock) broke the leapsecond update of CLOCK_MONOTONIC. The missing leapsecond update to wall_to_monotonic causes discontinuities in CLOCK_MONOTONIC. Adjust wall_to_monotonic when NTP inserted a leapsecond. Reported-by: Richard Cochran <richardcochran@gmail.com> Signed-off-by: John Stultz <john.stultz@linaro.org> Tested-by: Richard Cochran <richardcochran@gmail.com> Cc: stable@kernel.org Link: http://lkml.kernel.org/r/1338400497-12420-1-git-send-email-john.stultz@linaro.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2012-06-04Merge branches 'irq-urgent-for-linus' and 'smp-hotplug-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull irq and smpboot updates from Thomas Gleixner: "Just cleanup patches with no functional change and a fix for suspend issues." * 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: genirq: Introduce irq_do_set_affinity() to reduce duplicated code genirq: Add IRQS_PENDING for nested and simple irq * 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: smpboot, idle: Fix comment mismatch over idle_threads_init() smpboot, idle: Optimize calls to smp_processor_id() in idle_threads_init()
2012-06-04Merge branch 'timers-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull timer updates from Thomas Gleixner: "The clocksource driver is pure hardware enablement and the skew option is default off, well tested and non dangerous." * 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: tick: Move skew_tick option into the HIGH_RES_TIMER section clocksource: em_sti: Add DT support clocksource: em_sti: Emma Mobile STI driver clockevents: Make clockevents_config() a global symbol tick: Add tick skew boot option
2012-06-01Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal Pull third pile of signal handling patches from Al Viro: "This time it's mostly helpers and conversions to them; there's a lot of stuff remaining in the tree, but that'll either go in -rc2 (isolated bug fixes, ideally via arch maintainers' trees) or will sit there until the next cycle." * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal: x86: get rid of calling do_notify_resume() when returning to kernel mode blackfin: check __get_user() return value whack-a-mole with TIF_FREEZE FRV: Optimise the system call exit path in entry.S [ver #2] FRV: Shrink TIF_WORK_MASK [ver #2] FRV: Prevent syscall exit tracing and notify_resume at end of kernel exceptions new helper: signal_delivered() powerpc: get rid of restore_sigmask() most of set_current_blocked() callers want SIGKILL/SIGSTOP removed from set set_restore_sigmask() is never called without SIGPENDING (and never should be) TIF_RESTORE_SIGMASK can be set only when TIF_SIGPENDING is set don't call try_to_freeze() from do_signal() pull clearing RESTORE_SIGMASK into block_sigmask() sh64: failure to build sigframe != signal without handler openrisc: tracehook_signal_handler() is supposed to be called on success new helper: sigmask_to_save() new helper: restore_saved_sigmask() new helpers: {clear,test,test_and_clear}_restore_sigmask() HAVE_RESTORE_SIGMASK is defined on all architectures now
2012-06-01Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs changes from Al Viro. "A lot of misc stuff. The obvious groups: * Miklos' atomic_open series; kills the damn abuse of ->d_revalidate() by NFS, which was the major stumbling block for all work in that area. * ripping security_file_mmap() and dealing with deadlocks in the area; sanitizing the neighborhood of vm_mmap()/vm_munmap() in general. * ->encode_fh() switched to saner API; insane fake dentry in mm/cleancache.c gone. * assorted annotations in fs (endianness, __user) * parts of Artem's ->s_dirty work (jff2 and reiserfs parts) * ->update_time() work from Josef. * other bits and pieces all over the place. Normally it would've been in two or three pull requests, but signal.git stuff had eaten a lot of time during this cycle ;-/" Fix up trivial conflicts in Documentation/filesystems/vfs.txt (the 'truncate_range' inode method was removed by the VM changes, the VFS update adds an 'update_time()' method), and in fs/btrfs/ulist.[ch] (due to sparse fix added twice, with other changes nearby). * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (95 commits) nfs: don't open in ->d_revalidate vfs: retry last component if opening stale dentry vfs: nameidata_to_filp(): don't throw away file on error vfs: nameidata_to_filp(): inline __dentry_open() vfs: do_dentry_open(): don't put filp vfs: split __dentry_open() vfs: do_last() common post lookup vfs: do_last(): add audit_inode before open vfs: do_last(): only return EISDIR for O_CREAT vfs: do_last(): check LOOKUP_DIRECTORY vfs: do_last(): make ENOENT exit RCU safe vfs: make follow_link check RCU safe vfs: do_last(): use inode variable vfs: do_last(): inline walk_component() vfs: do_last(): make exit RCU safe vfs: split do_lookup() Btrfs: move over to use ->update_time fs: introduce inode operation ->update_time reiserfs: get rid of resierfs_sync_super reiserfs: mark the superblock as dirty a bit later ...
2012-06-01new helper: signal_delivered()Al Viro
Does block_sigmask() + tracehook_signal_handler(); called when sigframe has been successfully built. All architectures converted to it; block_sigmask() itself is gone now (merged into this one). I'm still not too happy with the signature, but that's a separate story (IMO we need a structure that would contain signal number + siginfo + k_sigaction, so that get_signal_to_deliver() would fill one, signal_delivered(), handle_signal() and probably setup...frame() - take one). Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>