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2012-01-25kprobes: initialize before using a hlistAnanth N Mavinakayanahalli
commit d496aab567e7e52b3e974c9192a5de6e77dce32c upstream. Commit ef53d9c5e ("kprobes: improve kretprobe scalability with hashed locking") introduced a bug where we can potentially leak kretprobe_instances since we initialize a hlist head after having used it. Initialize the hlist head before using it. Reported by: Jim Keniston <jkenisto@us.ibm.com> Acked-by: Jim Keniston <jkenisto@us.ibm.com> Signed-off-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Srinivasa D S <srinivasa@in.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2012-01-25tracepoints/module: Fix disabling tracepoints with taint CRAP or OOTSteven Rostedt
commit c10076c4304083af15a41f6bc5e657e781c1f9a6 upstream. Tracepoints are disabled for tainted modules, which is usually because the module is either proprietary or was forced, and we don't want either of them using kernel tracepoints. But, a module can also be tainted by being in the staging directory or compiled out of tree. Either is fine for use with tracepoints, no need to punish them. I found this out when I noticed that my sample trace event module, when done out of tree, stopped working. Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Ben Hutchings <ben@decadent.org.uk> Cc: Dave Jones <davej@redhat.com> Cc: Greg Kroah-Hartman <gregkh@suse.de> Cc: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2012-01-25ftrace: Fix unregister ftrace_ops accountingJiri Olsa
commit 30fb6aa74011dcf595f306ca2727254d708b786e upstream. Multiple users of the function tracer can register their functions with the ftrace_ops structure. The accounting within ftrace will update the counter on each function record that is being traced. When the ftrace_ops filtering adds or removes functions, the function records will be updated accordingly if the ftrace_ops is still registered. When a ftrace_ops is removed, the counter of the function records, that the ftrace_ops traces, are decremented. When they reach zero the functions that they represent are modified to stop calling the mcount code. When changes are made, the code is updated via stop_machine() with a command passed to the function to tell it what to do. There is an ENABLE and DISABLE command that tells the called function to enable or disable the functions. But the ENABLE is really a misnomer as it should just update the records, as records that have been enabled and now have a count of zero should be disabled. The DISABLE command is used to disable all functions regardless of their counter values. This is the big off switch and is not the complement of the ENABLE command. To make matters worse, when a ftrace_ops is unregistered and there is another ftrace_ops registered, neither the DISABLE nor the ENABLE command are set when calling into the stop_machine() function and the records will not be updated to match their counter. A command is passed to that function that will update the mcount code to call the registered callback directly if it is the only one left. This means that the ftrace_ops that is still registered will have its callback called by all functions that have been set for it as well as the ftrace_ops that was just unregistered. Here's a way to trigger this bug. Compile the kernel with CONFIG_FUNCTION_PROFILER set and with CONFIG_FUNCTION_GRAPH not set: CONFIG_FUNCTION_PROFILER=y # CONFIG_FUNCTION_GRAPH is not set This will force the function profiler to use the function tracer instead of the function graph tracer. # cd /sys/kernel/debug/tracing # echo schedule > set_ftrace_filter # echo function > current_tracer # cat set_ftrace_filter schedule # cat trace # tracer: nop # # entries-in-buffer/entries-written: 692/68108025 #P:4 # # _-----=> irqs-off # / _----=> need-resched # | / _---=> hardirq/softirq # || / _--=> preempt-depth # ||| / delay # TASK-PID CPU# |||| TIMESTAMP FUNCTION # | | | |||| | | kworker/0:2-909 [000] .... 531.235574: schedule <-worker_thread <idle>-0 [001] .N.. 531.235575: schedule <-cpu_idle kworker/0:2-909 [000] .... 531.235597: schedule <-worker_thread sshd-2563 [001] .... 531.235647: schedule <-schedule_hrtimeout_range_clock # echo 1 > function_profile_enabled # echo 0 > function_porfile_enabled # cat set_ftrace_filter schedule # cat trace # tracer: function # # entries-in-buffer/entries-written: 159701/118821262 #P:4 # # _-----=> irqs-off # / _----=> need-resched # | / _---=> hardirq/softirq # || / _--=> preempt-depth # ||| / delay # TASK-PID CPU# |||| TIMESTAMP FUNCTION # | | | |||| | | <idle>-0 [002] ...1 604.870655: local_touch_nmi <-cpu_idle <idle>-0 [002] d..1 604.870655: enter_idle <-cpu_idle <idle>-0 [002] d..1 604.870656: atomic_notifier_call_chain <-enter_idle <idle>-0 [002] d..1 604.870656: __atomic_notifier_call_chain <-atomic_notifier_call_chain The same problem could have happened with the trace_probe_ops, but they are modified with the set_frace_filter file which does the update at closure of the file. The simple solution is to change ENABLE to UPDATE and call it every time an ftrace_ops is unregistered. Link: http://lkml.kernel.org/r/1323105776-26961-3-git-send-email-jolsa@redhat.com Signed-off-by: Jiri Olsa <jolsa@redhat.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2012-01-12cgroup: fix to allow mounting a hierarchy by nameLi Zefan
commit 0d19ea866562e46989412a0676412fa0983c9ce7 upstream. If we mount a hierarchy with a specified name, the name is unique, and we can use it to mount the hierarchy without specifying its set of subsystem names. This feature is documented is Documentation/cgroups/cgroups.txt section 2.3 Here's an example: # mount -t cgroup -o cpuset,name=myhier xxx /cgroup1 # mount -t cgroup -o name=myhier xxx /cgroup2 But it was broken by commit 32a8cf235e2f192eb002755076994525cdbaa35a (cgroup: make the mount options parsing more accurate) This fixes the regression. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2012-01-04ptrace: ensure JOBCTL_STOP_SIGMASK is not zero after detachOleg Nesterov
This is the temporary simple fix for 3.2, we need more changes in this area. 1. do_signal_stop() assumes that the running untraced thread in the stopped thread group is not possible. This was our goal but it is not yet achieved: a stopped-but-resumed tracee can clone the running thread which can initiate another group-stop. Remove WARN_ON_ONCE(!current->ptrace). 2. A new thread always starts with ->jobctl = 0. If it is auto-attached and this group is stopped, __ptrace_unlink() sets JOBCTL_STOP_PENDING but JOBCTL_STOP_SIGMASK part is zero, this triggers WANR_ON(!signr) in do_jobctl_trap() if another debugger attaches. Change __ptrace_unlink() to set the artificial SIGSTOP for report. Alternatively we could change ptrace_init_task() to copy signr from current, but this means we can copy it for no reason and hide the possible similar problems. Acked-by: Tejun Heo <tj@kernel.org> Cc: <stable@kernel.org> [3.1] Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-01-04ptrace: partially fix the do_wait(WEXITED) vs EXIT_DEAD->EXIT_ZOMBIE raceOleg Nesterov
Test-case: int main(void) { int pid, status; pid = fork(); if (!pid) { for (;;) { if (!fork()) return 0; if (waitpid(-1, &status, 0) < 0) { printf("ERR!! wait: %m\n"); return 0; } } } assert(ptrace(PTRACE_ATTACH, pid, 0,0) == 0); assert(waitpid(-1, NULL, 0) == pid); assert(ptrace(PTRACE_SETOPTIONS, pid, 0, PTRACE_O_TRACEFORK) == 0); do { ptrace(PTRACE_CONT, pid, 0, 0); pid = waitpid(-1, NULL, 0); } while (pid > 0); return 1; } It fails because ->real_parent sees its child in EXIT_DEAD state while the tracer is going to change the state back to EXIT_ZOMBIE in wait_task_zombie(). The offending commit is 823b018e which moved the EXIT_DEAD check, but in fact we should not blame it. The original code was not correct as well because it didn't take ptrace_reparented() into account and because we can't really trust ->ptrace. This patch adds the additional check to close this particular race but it doesn't solve the whole problem. We simply can't rely on ->ptrace in this case, it can be cleared if the tracer is multithreaded by the exiting ->parent. I think we should kill EXIT_DEAD altogether, we should always remove the soon-to-be-reaped child from ->children or at least we should never do the DEAD->ZOMBIE transition. But this is too complex for 3.2. Reported-and-tested-by: Denys Vlasenko <vda.linux@googlemail.com> Tested-by: Lukasz Michalik <lmi@ift.uni.wroc.pl> Acked-by: Tejun Heo <tj@kernel.org> Cc: <stable@kernel.org> [3.0+] Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-01-03hung_task: fix false positive during vforkMandeep Singh Baines
vfork parent uninterruptibly and unkillably waits for its child to exec/exit. This wait is of unbounded length. Ignore such waits in the hung_task detector. Signed-off-by: Mandeep Singh Baines <msb@chromium.org> Reported-by: Sasha Levin <levinsasha928@gmail.com> LKML-Reference: <1325344394.28904.43.camel@lappy> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: John Kacur <jkacur@redhat.com> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-12-31futex: Fix uninterruptible loop due to gate_areaHugh Dickins
It was found (by Sasha) that if you use a futex located in the gate area we get stuck in an uninterruptible infinite loop, much like the ZERO_PAGE issue. While looking at this problem, PeterZ realized you'll get into similar trouble when hitting any install_special_pages() mapping. And are there still drivers setting up their own special mmaps without page->mapping, and without special VM or pte flags to make get_user_pages fail? In most cases, if page->mapping is NULL, we do not need to retry at all: Linus points out that even /proc/sys/vm/drop_caches poses no problem, because it ends up using remove_mapping(), which takes care not to interfere when the page reference count is raised. But there is still one case which does need a retry: if memory pressure called shmem_writepage in between get_user_pages_fast dropping page table lock and our acquiring page lock, then the page gets switched from filecache to swapcache (and ->mapping set to NULL) whatever the refcount. Fault it back in to get the page->mapping needed for key->shared.inode. Reported-by: Sasha Levin <levinsasha928@gmail.com> Signed-off-by: Hugh Dickins <hughd@google.com> Cc: stable@vger.kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-12-30Revert "clockevents: Set noop handler in clockevents_exchange_device()"Linus Torvalds
This reverts commit de28f25e8244c7353abed8de0c7792f5f883588c. It results in resume problems for various people. See for example http://thread.gmane.org/gmane.linux.kernel/1233033 http://thread.gmane.org/gmane.linux.kernel/1233389 http://thread.gmane.org/gmane.linux.kernel/1233159 http://thread.gmane.org/gmane.linux.kernel/1227868/focus=1230877 and the fedora and ubuntu bug reports https://bugzilla.redhat.com/show_bug.cgi?id=767248 https://bugs.launchpad.net/ubuntu/+source/linux/+bug/904569 which got bisected down to the stable version of this commit. Reported-by: Jonathan Nieder <jrnieder@gmail.com> Reported-by: Phil Miller <mille121@illinois.edu> Reported-by: Philip Langdale <philipl@overt.org> Reported-by: Tim Gardner <tim.gardner@canonical.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Greg KH <gregkh@suse.de> Cc: stable@kernel.org # for stable kernels that applied the original Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-12-20Merge branch 'for-3.2-fixes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup * 'for-3.2-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: cgroups: fix a css_set not found bug in cgroup_attach_proc
2011-12-20Merge branch 'timers-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip * 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: time/clocksource: Fix kernel-doc warnings rtc: m41t80: Workaround broken alarm functionality rtc: Expire alarms after the time is set.
2011-12-20binary_sysctl(): fix memory leakMichel Lespinasse
binary_sysctl() calls sysctl_getname() which allocates from names_cache slab usin __getname() The matching function to free the name is __putname(), and not putname() which should be used only to match getname() allocations. This is because when auditing is enabled, putname() calls audit_putname *instead* (not in addition) to __putname(). Then, if a syscall is in progress, audit_putname does not release the name - instead, it expects the name to get released when the syscall completes, but that will happen only if audit_getname() was called previously, i.e. if the name was allocated with getname() rather than the naked __getname(). So, __getname() followed by putname() ends up leaking memory. Signed-off-by: Michel Lespinasse <walken@google.com> Acked-by: Al Viro <viro@zeniv.linux.org.uk> Cc: Christoph Hellwig <hch@infradead.org> Cc: Eric Paris <eparis@redhat.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-12-20cpusets: stall when updating mems_allowed for mempolicy or disjoint nodemaskDavid Rientjes
Kernels where MAX_NUMNODES > BITS_PER_LONG may temporarily see an empty nodemask in a tsk's mempolicy if its previous nodemask is remapped onto a new set of allowed cpuset nodes where the two nodemasks, as a result of the remap, are now disjoint. c0ff7453bb5c ("cpuset,mm: fix no node to alloc memory when changing cpuset's mems") adds get_mems_allowed() to prevent the set of allowed nodes from changing for a thread. This causes any update to a set of allowed nodes to stall until put_mems_allowed() is called. This stall is unncessary, however, if at least one node remains unchanged in the update to the set of allowed nodes. This was addressed by 89e8a244b97e ("cpusets: avoid looping when storing to mems_allowed if one node remains set"), but it's still possible that an empty nodemask may be read from a mempolicy because the old nodemask may be remapped to the new nodemask during rebind. To prevent this, only avoid the stall if there is no mempolicy for the thread being changed. This is a temporary solution until all reads from mempolicy nodemasks can be guaranteed to not be empty without the get_mems_allowed() synchronization. Also moves the check for nodemask intersection inside task_lock() so that tsk->mems_allowed cannot change. This ensures that nothing can set this tsk's mems_allowed out from under us and also protects tsk->mempolicy. Reported-by: Miao Xie <miaox@cn.fujitsu.com> Signed-off-by: David Rientjes <rientjes@google.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Paul Menage <paul@paulmenage.org> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-12-19cgroups: fix a css_set not found bug in cgroup_attach_procMandeep Singh Baines
There is a BUG when migrating a PF_EXITING proc. Since css_set_prefetch() is not called for the PF_EXITING case, find_existing_css_set() will return NULL inside cgroup_task_migrate() causing a BUG. This bug is easy to reproduce. Create a zombie and echo its pid to cgroup.procs. $ cat zombie.c \#include <unistd.h> int main() { if (fork()) pause(); return 0; } $ We are hitting this bug pretty regularly on ChromeOS. This bug is already fixed by Tejun Heo's cgroup patchset which is targetted for the next merge window: https://lkml.org/lkml/2011/11/1/356 I've create a smaller patch here which just fixes this bug so that a fix can be merged into the current release and stable. Signed-off-by: Mandeep Singh Baines <msb@chromium.org> Downstream-Bug-Report: http://crosbug.com/23953 Reviewed-by: Li Zefan <lizf@cn.fujitsu.com> Signed-off-by: Tejun Heo <tj@kernel.org> Cc: containers@lists.linux-foundation.org Cc: cgroups@vger.kernel.org Cc: stable@kernel.org Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Paul Menage <paul@paulmenage.org> Cc: Olof Johansson <olofj@chromium.org>
2011-12-19time/clocksource: Fix kernel-doc warningsKusanagi Kouichi
Fix various KernelDoc build warnings. Signed-off-by: Kusanagi Kouichi <slash@ac.auone-net.jp> Cc: John Stultz <johnstul@us.ibm.com> Link: http://lkml.kernel.org/r/20111219091320.0D5AF6FC03D@msa105.auone-net.jp Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-12-17Merge branches 'perf-urgent-for-linus' and 'sched-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf events: Fix ring_buffer_wakeup() brown paperbag bug * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched: Fix select_idle_sibling() regression in selecting an idle SMT sibling MAINTAINERS: Update tip.git related git trees
2011-12-16sched: Fix select_idle_sibling() regression in selecting an idle SMT siblingPeter Zijlstra
Mike Galbraith reported that this recent commit: commit 4dcfe1025b513c2c1da5bf5586adb0e80148f612 Author: Peter Zijlstra <peterz@infradead.org> Date: Thu Nov 10 13:01:10 2011 +0100 sched: Avoid SMT siblings in select_idle_sibling() if possible stopped selecting an idle SMT sibling when there are no idle cores in a single socket system. Intent of the select_idle_sibling() was to fallback to an idle SMT sibling, if it fails to identify an idle core. But this fallback was not happening on systems where all the scheduler domains had `SD_SHARE_PKG_RESOURCES' flag set. Fix it. Slightly bigger patch of cleaning all these goto's etc is queued up for the next release. Reported-by: Mike Galbraith <efault@gmx.de> Reported-by: Alex Shi <alex.shi@intel.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Link: http://lkml.kernel.org/r/1323978421.1984.244.camel@sbsiddha-desk.sc.intel.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-12-14perf events: Fix ring_buffer_wakeup() brown paperbag bugWill Deacon
Commit 10c6db11 ("perf: Fix loss of notification with multi-event") seems to unconditionally dereference event->rb in the wakeup handler, this is wrong, there might not be a buffer attached. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20111213152651.GP20297@mudshark.cambridge.arm.com [ minor edits ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-12-09Merge branch 'perf-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf: Do no try to schedule task events if there are none lockdep, kmemcheck: Annotate ->lock in lockdep_init_map() perf header: Use event_name() to get an event name perf stat: Failure with "Operation not supported"
2011-12-09sys_getppid: add missing rcu_dereferenceMandeep Singh Baines
In order to safely dereference current->real_parent inside an rcu_read_lock, we need an rcu_dereference. Signed-off-by: Mandeep Singh Baines <msb@chromium.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Pavel Emelyanov <xemul@openvz.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Kees Cook <keescook@chromium.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-12-09printk: avoid double lock acquirePeter Zijlstra
Commit 4f2a8d3cf5e ("printk: Fix console_sem vs logbuf_lock unlock race") introduced another silly bug where we would want to acquire an already held lock. Avoid this. Reported-by: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-12-08Merge branch 'timers-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip * 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: alarmtimers: Fix time comparison ptp: Fix clock_getres() implementation
2011-12-07perf: Do no try to schedule task events if there are noneGleb Natapov
perf_event_sched_in() shouldn't try to schedule task events if there are none otherwise task's ctx->is_active will be set and will not be cleared during sched_out. This will prevent newly added events from being scheduled into the task context. Fixes a boo-boo in commit 1d5f003f5a9 ("perf: Do not set task_ctx pointer in cpuctx if there are no events in the context"). Signed-off-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20111122140821.GF2557@redhat.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-12-06Merge branch 'perf-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: ftrace: Fix hash record accounting bug perf: Fix parsing of __print_flags() in TP_printk() jump_label: jump_label_inc may return before the code is patched ftrace: Remove force undef config value left for testing tracing: Restore system filter behavior tracing: fix event_subsystem ref counting
2011-12-06lockdep, kmemcheck: Annotate ->lock in lockdep_init_map()Yong Zhang
Since commit f59de89 ("lockdep: Clear whole lockdep_map on initialization"), lockdep_init_map() will clear all the struct. But it will break lock_set_class()/lock_set_subclass(). A typical race condition is like below: CPU A CPU B lock_set_subclass(lockA); lock_set_class(lockA); lockdep_init_map(lockA); /* lockA->name is cleared */ memset(lockA); __lock_acquire(lockA); /* lockA->class_cache[] is cleared */ register_lock_class(lockA); look_up_lock_class(lockA); WARN_ON_ONCE(class->name != lock->name); lock->name = name; So restore to what we have done before commit f59de89 but annotate ->lock with kmemcheck_mark_initialized() to suppress the kmemcheck warning reported in commit f59de89. Reported-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Reported-by: Borislav Petkov <bp@alien8.de> Suggested-by: Vegard Nossum <vegard.nossum@gmail.com> Signed-off-by: Yong Zhang <yong.zhang0@gmail.com> Cc: Tejun Heo <tj@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: <stable@kernel.org> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20111109080451.GB8124@zhy Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-12-06alarmtimers: Fix time comparisonThomas Gleixner
The expiry function compares the timer against current time and does not expire the timer when the expiry time is >= now. That's wrong. If the timer is set for now, then it must expire. Make the condition expiry > now for breaking out the loop. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: John Stultz <john.stultz@linaro.org> Cc: stable@kernel.org
2011-12-05Merge branch 'perf-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf: Fix loss of notification with multi-event perf, x86: Force IBS LVT offset assignment for family 10h perf, x86: Disable PEBS on SandyBridge chips trace_events_filter: Use rcu_assign_pointer() when setting ftrace_event_call->filter perf session: Fix crash with invalid CPU list perf python: Fix undefined symbol problem perf/x86: Enable raw event access to Intel offcore events perf: Don't use -ENOSPC for out of PMU resources perf: Do not set task_ctx pointer in cpuctx if there are no events in the context perf/x86: Fix PEBS instruction unwind oprofile, x86: Fix crash when unloading module (nmi timer mode) oprofile: Fix crash when unloading module (hr timer mode)
2011-12-05Merge branch 'timers-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip * 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: clockevents: Set noop handler in clockevents_exchange_device() tick-broadcast: Stop active broadcast device when replacing it clocksource: Fix bug with max_deferment margin calculation rtc: Fix some bugs that allowed accumulating time drift in suspend/resume rtc: Disable the alarm in the hardware
2011-12-05Merge branches 'core-urgent-for-linus' and 'irq-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip * 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: slab, lockdep: Fix silly bug * 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: genirq: Fix race condition when stopping the irq thread
2011-12-05Merge branch 'sched-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched, x86: Avoid unnecessary overflow in sched_clock sched: Fix buglet in return_cfs_rq_runtime() sched: Avoid SMT siblings in select_idle_sibling() if possible sched: Set the command name of the idle tasks in SMP kernels sched, rt: Provide means of disabling cross-cpu bandwidth sharing sched: Document wait_for_completion_*() return values sched_fair: Fix a typo in the comment describing update_sd_lb_stats sched: Add a comment to effective_load() since it's a pain
2011-12-05ftrace: Fix hash record accounting bugSteven Rostedt
If the set_ftrace_filter is cleared by writing just whitespace to it, then the filter hash refcounts will be decremented but not updated. This causes two bugs: 1) No functions will be enabled for tracing when they all should be 2) If the users clears the set_ftrace_filter twice, it will crash ftrace: ------------[ cut here ]------------ WARNING: at /home/rostedt/work/git/linux-trace.git/kernel/trace/ftrace.c:1384 __ftrace_hash_rec_update.part.27+0x157/0x1a7() Modules linked in: Pid: 2330, comm: bash Not tainted 3.1.0-test+ #32 Call Trace: [<ffffffff81051828>] warn_slowpath_common+0x83/0x9b [<ffffffff8105185a>] warn_slowpath_null+0x1a/0x1c [<ffffffff810ba362>] __ftrace_hash_rec_update.part.27+0x157/0x1a7 [<ffffffff810ba6e8>] ? ftrace_regex_release+0xa7/0x10f [<ffffffff8111bdfe>] ? kfree+0xe5/0x115 [<ffffffff810ba51e>] ftrace_hash_move+0x2e/0x151 [<ffffffff810ba6fb>] ftrace_regex_release+0xba/0x10f [<ffffffff8112e49a>] fput+0xfd/0x1c2 [<ffffffff8112b54c>] filp_close+0x6d/0x78 [<ffffffff8113a92d>] sys_dup3+0x197/0x1c1 [<ffffffff8113a9a6>] sys_dup2+0x4f/0x54 [<ffffffff8150cac2>] system_call_fastpath+0x16/0x1b ---[ end trace 77a3a7ee73794a02 ]--- Link: http://lkml.kernel.org/r/20111101141420.GA4918@debian Reported-by: Rabin Vincent <rabin@rab.in> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-12-05jump_label: jump_label_inc may return before the code is patchedGleb Natapov
If cpu A calls jump_label_inc() just after atomic_add_return() is called by cpu B, atomic_inc_not_zero() will return value greater then zero and jump_label_inc() will return to a caller before jump_label_update() finishes its job on cpu B. Link: http://lkml.kernel.org/r/20111018175551.GH17571@redhat.com Cc: stable@vger.kernel.org Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Jason Baron <jbaron@redhat.com> Signed-off-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-12-05ftrace: Remove force undef config value left for testingSteven Rostedt
A forced undef of a config value was used for testing and was accidently left in during the final commit. This causes x86 to run slower than needed while running function tracing as well as causes the function graph selftest to fail when DYNMAIC_FTRACE is not set. This is because the code in MCOUNT expects the ftrace code to be processed with the config value set that happened to be forced not set. The forced config option was left in by: commit 6331c28c962561aee59e5a493b7556a4bb585957 ftrace: Fix dynamic selftest failure on some archs Link: http://lkml.kernel.org/r/20111102150255.GA6973@debian Cc: stable@vger.kernel.org Reported-by: Rabin Vincent <rabin@rab.in> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-12-05tracing: Restore system filter behaviorLi Zefan
Though not all events have field 'prev_pid', it was allowed to do this: # echo 'prev_pid == 100' > events/sched/filter but commit 75b8e98263fdb0bfbdeba60d4db463259f1fe8a2 (tracing/filter: Swap entire filter of events) broke it without any reason. Link: http://lkml.kernel.org/r/4EAF46CF.8040408@cn.fujitsu.com Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-12-05tracing: fix event_subsystem ref countingIlya Dryomov
Fix a bug introduced by e9dbfae5, which prevents event_subsystem from ever being released. Ref_count was added to keep track of subsystem users, not for counting events. Subsystem is created with ref_count = 1, so there is no need to increment it for every event, we have nr_events for that. Fix this by touching ref_count only when we actually have a new user - subsystem_open(). Cc: stable@vger.kernel.org Signed-off-by: Ilya Dryomov <idryomov@gmail.com> Link: http://lkml.kernel.org/r/1320052062-7846-1-git-send-email-idryomov@gmail.com Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-12-05Merge branch 'tip/perf/urgent' of ↵Ingo Molnar
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace into perf/urgent
2011-12-05perf: Fix loss of notification with multi-eventPeter Zijlstra
When you do: $ perf record -e cycles,cycles,cycles noploop 10 You expect about 10,000 samples for each event, i.e., 10s at 1000samples/sec. However, this is not what's happening. You get much fewer samples, maybe 3700 samples/event: $ perf report -D | tail -15 Aggregated stats: TOTAL events: 10998 MMAP events: 66 COMM events: 2 SAMPLE events: 10930 cycles stats: TOTAL events: 3644 SAMPLE events: 3644 cycles stats: TOTAL events: 3642 SAMPLE events: 3642 cycles stats: TOTAL events: 3644 SAMPLE events: 3644 On a Intel Nehalem or even AMD64, there are 4 counters capable of measuring cycles, so there is plenty of space to measure those events without multiplexing (even with the NMI watchdog active). And even with multiplexing, we'd expect roughly the same number of samples per event. The root of the problem was that when the event that caused the buffer to become full was not the first event passed on the cmdline, the user notification would get lost. The notification was sent to the file descriptor of the overflowed event but the perf tool was not polling on it. The perf tool aggregates all samples into a single buffer, i.e., the buffer of the first event. Consequently, it assumes notifications for any event will come via that descriptor. The seemingly straight forward solution of moving the waitq into the ringbuffer object doesn't work because of life-time issues. One could perf_event_set_output() on a fd that you're also blocking on and cause the old rb object to be freed while its waitq would still be referenced by the blocked thread -> FAIL. Therefore link all events to the ringbuffer and broadcast the wakeup from the ringbuffer object to all possible events that could be waited upon. This is rather ugly, and we're open to better solutions but it works for now. Reported-by: Stephane Eranian <eranian@google.com> Finished-by: Stephane Eranian <eranian@google.com> Reviewed-by: Stephane Eranian <eranian@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20111126014731.GA7030@quad Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-12-02clockevents: Set noop handler in clockevents_exchange_device()Thomas Gleixner
If a device is shutdown, then there might be a pending interrupt, which will be processed after we reenable interrupts, which causes the original handler to be run. If the old handler is the (broadcast) periodic handler the shutdown state might hang the kernel completely. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org
2011-12-02tick-broadcast: Stop active broadcast device when replacing itThomas Gleixner
When a better rated broadcast device is installed, then the current active device is not disabled, which results in two running broadcast devices. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org
2011-12-02genirq: Fix race condition when stopping the irq threadIdo Yariv
In irq_wait_for_interrupt(), the should_stop member is verified before setting the task's state to TASK_INTERRUPTIBLE and calling schedule(). In case kthread_stop sets should_stop and wakes up the process after should_stop is checked by the irq thread but before the task's state is changed, the irq thread might never exit: kthread_stop irq_wait_for_interrupt ------------ ---------------------- ... ... while (!kthread_should_stop()) { kthread->should_stop = 1; wake_up_process(k); wait_for_completion(&kthread->exited); ... set_current_state(TASK_INTERRUPTIBLE); ... schedule(); } Fix this by checking if the thread should stop after modifying the task's state. [ tglx: Simplified it a bit ] Signed-off-by: Ido Yariv <ido@wizery.com> Link: http://lkml.kernel.org/r/1322740508-22640-1-git-send-email-ido@wizery.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@kernel.org
2011-12-01trace_events_filter: Use rcu_assign_pointer() when setting ↵Tejun Heo
ftrace_event_call->filter ftrace_event_call->filter is sched RCU protected but didn't use rcu_assign_pointer(). Use it. TODO: Add proper __rcu annotation to call->filter and all its users. -v2: Use RCU_INIT_POINTER() for %NULL clearing as suggested by Eric. Link: http://lkml.kernel.org/r/20111123164949.GA29639@google.com Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: stable@kernel.org # (2.6.39+) Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-12-01clocksource: Fix bug with max_deferment margin calculationYang Honggang (Joseph)
In order to leave a margin of 12.5% we should >> 3 not >> 5. CC: stable@kernel.org Signed-off-by: Yang Honggang (Joseph) <eagle.rtlinux@gmail.com> [jstultz: Modified commit subject] Signed-off-by: John Stultz <john.stultz@linaro.org>
2011-11-29Merge branch 'pm-fixes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm * 'pm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: PM: Update comments describing device power management callbacks PM / Sleep: Update documentation related to system wakeup PM / Runtime: Make documentation follow the new behavior of irq_safe PM / Sleep: Correct inaccurate information in devices.txt PM / Domains: Document how PM domains are used by the PM core PM / Hibernate: Do not leak memory in error/test code paths
2011-11-28Merge branch 'for-3.2-fixes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup * 'for-3.2-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: cgroup_freezer: fix freezing groups with stopped tasks
2011-11-28Merge branch 'timers-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip * 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: hrtimer: Fix extra wakeups from __remove_hrtimer() timekeeping: add arch_offset hook to ktime_get functions clocksource: Avoid selecting mult values that might overflow when adjusted time: Improve documentation of timekeeeping_adjust()
2011-11-28Merge branch 'irq-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip * 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: genirq: Don't allow per cpu interrupts to be suspended
2011-11-28genirq: fix regression in irqfixup, irqpollEdward Donovan
Commit fa27271bc8d2("genirq: Fixup poll handling") introduced a regression that broke irqfixup/irqpoll for some hardware configurations. Amidst reorganizing 'try_one_irq', that patch removed a test that checked for 'action->handler' returning IRQ_HANDLED, before acting on the interrupt. Restoring this test back returns the functionality lost since 2.6.39. In the current set of tests, after 'action' is set, it must precede '!action->next' to take effect. With this and my previous patch to irq/spurious.c, c75d720fca8a, all IRQ regressions that I have encountered are fixed. Signed-off-by: Edward Donovan <edward.donovan@numble.net> Reported-and-tested-by: Rogério Brito <rbrito@ime.usp.br> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: stable@kernel.org (2.6.39+) Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-11-24cgroup_freezer: fix freezing groups with stopped tasksMichal Hocko
2d3cbf8b (cgroup_freezer: update_freezer_state() does incorrect state transitions) removed is_task_frozen_enough and replaced it with a simple frozen call. This, however, breaks freezing for a group with stopped tasks because those cannot be frozen and so the group remains in CGROUP_FREEZING state (update_if_frozen doesn't count stopped tasks) and never reaches CGROUP_FROZEN. Let's add is_task_frozen_enough back and use it at the original locations (update_if_frozen and try_to_freeze_cgroup). Semantically we consider stopped tasks as frozen enough so we should consider both cases when testing frozen tasks. Testcase: mkdir /dev/freezer mount -t cgroup -o freezer none /dev/freezer mkdir /dev/freezer/foo sleep 1h & pid=$! kill -STOP $pid echo $pid > /dev/freezer/foo/tasks echo FROZEN > /dev/freezer/foo/freezer.state while true do cat /dev/freezer/foo/freezer.state [ "`cat /dev/freezer/foo/freezer.state`" = "FROZEN" ] && break sleep 1 done echo OK Signed-off-by: Michal Hocko <mhocko@suse.cz> Acked-by: Li Zefan <lizf@cn.fujitsu.com> Cc: Tomasz Buchert <tomasz.buchert@inria.fr> Cc: Paul Menage <paul@paulmenage.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: stable@kernel.org Signed-off-by: Tejun Heo <htejun@gmail.com>
2011-11-23PM / Hibernate: Do not leak memory in error/test code pathsRafael J. Wysocki
The hibernation core code forgets to release memory preallocated for hibernation if there's an error in its early stages or if test modes causing hibernation_snapshot() to return early are used. This causes the system to be hardly usable, because the amount of preallocated memory is usually huge. Fix this problem. Reported-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
2011-11-22Merge branch 'writeback-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/wfg/linux * 'writeback-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/wfg/linux: writeback: remove vm_dirties and task->dirties writeback: hard throttle 1000+ dd on a slow USB stick mm: Make task in balance_dirty_pages() killable