linux/kernel, branch v3.14.5

tracing: Use rcu_dereference_sched() for trace event triggers

2014-05-31T20:20:30Z

commit 561a4fe851ccab9dd0d14989ab566f9392d9f8b5 upstream. As trace event triggers are now part of the mainline kernel, I added my trace event trigger tests to my test suite I run on all my kernels. Now these tests get run under different config options, and one of those options is CONFIG_PROVE_RCU, which checks under lockdep that the rcu locking primitives are being used correctly. This triggered the following splat: =============================== [ INFO: suspicious RCU usage. ] 3.15.0-rc2-test+ #11 Not tainted ------------------------------- kernel/trace/trace_events_trigger.c:80 suspicious rcu_dereference_check() usage! other info that might help us debug this: rcu_scheduler_active = 1, debug_locks = 0 4 locks held by swapper/1/0: #0: ((&(&j_cdbs->work)->timer)){..-...}, at: [] call_timer_fn+0x5/0x1be #1: (&(&pool->lock)->rlock){-.-...}, at: [] __queue_work+0x140/0x283 #2: (&p->pi_lock){-.-.-.}, at: [] try_to_wake_up+0x2e/0x1e8 #3: (&rq->lock){-.-.-.}, at: [] try_to_wake_up+0x1a0/0x1e8 stack backtrace: CPU: 1 PID: 0 Comm: swapper/1 Not tainted 3.15.0-rc2-test+ #11 Hardware name: /DG965MQ, BIOS MQ96510J.86A.0372.2006.0605.1717 06/05/2006 0000000000000001 ffff88007e083b98 ffffffff819f53a5 0000000000000006 ffff88007b0942c0 ffff88007e083bc8 ffffffff81081307 ffff88007ad96d20 0000000000000000 ffff88007af2d840 ffff88007b2e701c ffff88007e083c18 Call Trace: [] dump_stack+0x4f/0x7c [] lockdep_rcu_suspicious+0x107/0x110 [] event_triggers_call+0x99/0x108 [] ftrace_event_buffer_commit+0x42/0xa4 [] ftrace_raw_event_sched_wakeup_template+0x71/0x7c [] ttwu_do_wakeup+0x7f/0xff [] ttwu_do_activate.constprop.126+0x5c/0x61 [] try_to_wake_up+0x1ac/0x1e8 [] wake_up_process+0x36/0x3b [] wake_up_worker+0x24/0x26 [] insert_work+0x5c/0x65 [] __queue_work+0x26c/0x283 [] ? __queue_work+0x283/0x283 [] delayed_work_timer_fn+0x1e/0x20 [] call_timer_fn+0xdf/0x1be^M [] ? call_timer_fn+0x5/0x1be [] ? __queue_work+0x283/0x283 [] run_timer_softirq+0x1a4/0x22f^M [] __do_softirq+0x17b/0x31b^M [] irq_exit+0x42/0x97 [] smp_apic_timer_interrupt+0x37/0x44 [] apic_timer_interrupt+0x6f/0x80 [] ? default_idle+0x21/0x32 [] ? default_idle+0x1f/0x32 [] arch_cpu_idle+0xf/0x11 [] cpu_startup_entry+0x1a3/0x213 [] start_secondary+0x212/0x219 The cause is that the triggers are protected by rcu_read_lock_sched() but the data is dereferenced with rcu_dereference() which expects it to be protected with rcu_read_lock(). The proper reference should be rcu_dereference_sched(). Cc: Tom Zanussi Signed-off-by: Steven Rostedt Signed-off-by: Greg Kroah-Hartman

tracing/uprobes: Fix uprobe_cpu_buffer memory leak

2014-05-31T20:20:29Z

commit 6ea6215fe394e320468589d9bba464a48f6d823a upstream. Forgot to free uprobe_cpu_buffer percpu page in uprobe_buffer_disable(). Link: http://lkml.kernel.org/p/534F8B3F.1090407@huawei.com Acked-by: Namhyung Kim Signed-off-by: zhangwei(Jovi) Signed-off-by: Steven Rostedt Signed-off-by: Greg Kroah-Hartman

tick-sched: Check tick_nohz_enabled in tick_nohz_switch_to_nohz()

2014-05-31T20:20:28Z

commit 27630532ef5ead28b98cfe28d8f95222ef91c2b7 upstream. Since commit d689fe222 (NOHZ: Check for nohz active instead of nohz enabled) the tick_nohz_switch_to_nohz() function returns because it checks for the tick_nohz_active flag. This can't be set, because the function itself sets it. Undo the change in tick_nohz_switch_to_nohz(). Signed-off-by: Viresh Kumar Cc: linaro-kernel@lists.linaro.org Cc: fweisbec@gmail.com Cc: Arvind.Chauhan@arm.com Cc: linaro-networking@linaro.org Link: http://lkml.kernel.org/r/40939c05f2d65d781b92b20302b02243d0654224.1397537987.git.viresh.kumar@linaro.org Signed-off-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman

tick-sched: Don't call update_wall_time() when delta is lesser than tick_period

2014-05-31T20:20:28Z

commit 03e6bdc5c4d0fc166bfd5d3cf749a5a0c1b5b1bd upstream. In tick_do_update_jiffies64() we are processing ticks only if delta is greater than tick_period. This is what we are supposed to do here and it broke a bit with this patch: commit 47a1b796 (tick/timekeeping: Call update_wall_time outside the jiffies lock) With above patch, we might end up calling update_wall_time() even if delta is found to be smaller that tick_period. Fix this by returning when the delta is less than tick period. [ tglx: Made it a 3 liner and massaged changelog ] Signed-off-by: Viresh Kumar Cc: linaro-kernel@lists.linaro.org Cc: fweisbec@gmail.com Cc: Arvind.Chauhan@arm.com Cc: linaro-networking@linaro.org Cc: John Stultz Link: http://lkml.kernel.org/r/80afb18a494b0bd9710975bcc4de134ae323c74f.1397537987.git.viresh.kumar@linaro.org Signed-off-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman

tick-common: Fix wrong check in tick_check_replacement()

2014-05-31T20:20:28Z

commit 521c42990e9d561ed5ed9f501f07639d0512b3c9 upstream. tick_check_replacement() returns if a replacement of clock_event_device is possible or not. It does this as the first check: if (tick_check_percpu(curdev, newdev, smp_processor_id())) return false; Thats wrong. tick_check_percpu() returns true when the device is useable. Check for false instead. [ tglx: Massaged changelog ] Signed-off-by: Viresh Kumar Cc: linaro-kernel@lists.linaro.org Cc: fweisbec@gmail.com Cc: Arvind.Chauhan@arm.com Cc: linaro-networking@linaro.org Link: http://lkml.kernel.org/r/486a02efe0246635aaba786e24b42d316438bf3b.1397537987.git.viresh.kumar@linaro.org Signed-off-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman

tracepoint: Do not waste memory on mods with no tracepoints

2014-05-31T20:20:28Z

commit 7dec935a3aa04412cba2cebe1524ae0d34a30c24 upstream. No reason to allocate tp_module structures for modules that have no tracepoints. This just wastes memory. Fixes: b75ef8b44b1c "Tracepoint: Dissociate from module mutex" Acked-by: Mathieu Desnoyers Signed-off-by: Steven Rostedt Signed-off-by: Greg Kroah-Hartman

blktrace: fix accounting of partially completed requests

2014-05-31T20:20:28Z

commit af5040da01ef980670b3741b3e10733ee3e33566 upstream. trace_block_rq_complete does not take into account that request can be partially completed, so we can get the following incorrect output of blkparser: C R 232 + 240 [0] C R 240 + 232 [0] C R 248 + 224 [0] C R 256 + 216 [0] but should be: C R 232 + 8 [0] C R 240 + 8 [0] C R 248 + 8 [0] C R 256 + 8 [0] Also, the whole output summary statistics of completed requests and final throughput will be incorrect. This patch takes into account real completion size of the request and fixes wrong completion accounting. Signed-off-by: Roman Pen CC: Steven Rostedt CC: Frederic Weisbecker CC: Ingo Molnar CC: linux-kernel@vger.kernel.org Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman

audit: convert PPIDs to the inital PID namespace.

2014-05-31T20:20:27Z

commit c92cdeb45eea38515e82187f48c2e4f435fb4e25 upstream. sys_getppid() returns the parent pid of the current process in its own pid namespace. Since audit filters are based in the init pid namespace, a process could avoid a filter or trigger an unintended one by being in an alternate pid namespace or log meaningless information. Switch to task_ppid_nr() for PPIDs to anchor all audit filters in the init_pid_ns. (informed by ebiederman's 6c621b7e) Cc: Eric W. Biederman Signed-off-by: Richard Guy Briggs Signed-off-by: Greg Kroah-Hartman

hung_task: check the value of "sysctl_hung_task_timeout_sec"

2014-05-06T14:59:35Z

commit 80df28476505ed4e6701c3448c63c9229a50c655 upstream. As sysctl_hung_task_timeout_sec is unsigned long, when this value is larger then LONG_MAX/HZ, the function schedule_timeout_interruptible in watchdog will return immediately without sleep and with print : schedule_timeout: wrong timeout value ffffffffffffff83 and then the funtion watchdog will call schedule_timeout_interruptible again and again. The screen will be filled with "schedule_timeout: wrong timeout value ffffffffffffff83" This patch does some check and correction in sysctl, to let the function schedule_timeout_interruptible allways get the valid parameter. Signed-off-by: Liu Hua Tested-by: Satoru Takeuchi Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

exit: call disassociate_ctty() before exit_task_namespaces()

2014-04-27T00:19:07Z

commit c39df5fa37b0623589508c95515b4aa1531c524e upstream. Commit 8aac62706ada ("move exit_task_namespaces() outside of exit_notify()") breaks pppd and the exiting service crashes the kernel: BUG: unable to handle kernel NULL pointer dereference at 0000000000000028 IP: ppp_register_channel+0x13/0x20 [ppp_generic] Call Trace: ppp_asynctty_open+0x12b/0x170 [ppp_async] tty_ldisc_open.isra.2+0x27/0x60 tty_ldisc_hangup+0x1e3/0x220 __tty_hangup+0x2c4/0x440 disassociate_ctty+0x61/0x270 do_exit+0x7f2/0xa50 ppp_register_channel() needs ->net_ns and current->nsproxy == NULL. Move disassociate_ctty() before exit_task_namespaces(), it doesn't make sense to delay it after perf_event_exit_task() or cgroup_exit(). This also allows to use task_work_add() inside the (nontrivial) code paths in disassociate_ctty(). Investigated by Peter Hurley. Signed-off-by: Oleg Nesterov Reported-by: Sree Harsha Totakura Cc: Peter Hurley Cc: Sree Harsha Totakura Cc: "Eric W. Biederman" Cc: Jeff Dike Cc: Ingo Molnar Cc: Andrey Vagin Cc: Al Viro Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman