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2013-04-08hrtimer: Add expiry time overflow check in hrtimer_interruptPrarit Bhargava
The settimeofday01 test in the LTP testsuite effectively does gettimeofday(current time); settimeofday(Jan 1, 1970 + 100 seconds); settimeofday(current time); This test causes a stack trace to be displayed on the console during the setting of timeofday to Jan 1, 1970 + 100 seconds: [ 131.066751] ------------[ cut here ]------------ [ 131.096448] WARNING: at kernel/time/clockevents.c:209 clockevents_program_event+0x135/0x140() [ 131.104935] Hardware name: Dinar [ 131.108150] Modules linked in: sg nfsv3 nfs_acl nfsv4 auth_rpcgss nfs dns_resolver fscache lockd sunrpc nf_conntrack_netbios_ns nf_conntrack_broadcast ipt_MASQUERADE ip6table_mangle ip6t_REJECT nf_conntrack_ipv6 nf_defrag_ipv6 iptable_nat nf_nat_ipv4 nf_nat iptable_mangle ipt_REJECT nf_conntrack_ipv4 nf_defrag_ipv4 xt_conntrack nf_conntrack ebtable_filter ebtables ip6table_filter ip6_tables iptable_filter ip_tables kvm_amd kvm sp5100_tco bnx2 i2c_piix4 crc32c_intel k10temp fam15h_power ghash_clmulni_intel amd64_edac_mod pcspkr serio_raw edac_mce_amd edac_core microcode xfs libcrc32c sr_mod sd_mod cdrom ata_generic crc_t10dif pata_acpi radeon i2c_algo_bit drm_kms_helper ttm drm ahci pata_atiixp libahci libata usb_storage i2c_core dm_mirror dm_region_hash dm_log dm_mod [ 131.176784] Pid: 0, comm: swapper/28 Not tainted 3.8.0+ #6 [ 131.182248] Call Trace: [ 131.184684] <IRQ> [<ffffffff810612af>] warn_slowpath_common+0x7f/0xc0 [ 131.191312] [<ffffffff8106130a>] warn_slowpath_null+0x1a/0x20 [ 131.197131] [<ffffffff810b9fd5>] clockevents_program_event+0x135/0x140 [ 131.203721] [<ffffffff810bb584>] tick_program_event+0x24/0x30 [ 131.209534] [<ffffffff81089ab1>] hrtimer_interrupt+0x131/0x230 [ 131.215437] [<ffffffff814b9600>] ? cpufreq_p4_target+0x130/0x130 [ 131.221509] [<ffffffff81619119>] smp_apic_timer_interrupt+0x69/0x99 [ 131.227839] [<ffffffff8161805d>] apic_timer_interrupt+0x6d/0x80 [ 131.233816] <EOI> [<ffffffff81099745>] ? sched_clock_cpu+0xc5/0x120 [ 131.240267] [<ffffffff814b9ff0>] ? cpuidle_wrap_enter+0x50/0xa0 [ 131.246252] [<ffffffff814b9fe9>] ? cpuidle_wrap_enter+0x49/0xa0 [ 131.252238] [<ffffffff814ba050>] cpuidle_enter_tk+0x10/0x20 [ 131.257877] [<ffffffff814b9c89>] cpuidle_idle_call+0xa9/0x260 [ 131.263692] [<ffffffff8101c42f>] cpu_idle+0xaf/0x120 [ 131.268727] [<ffffffff815f8971>] start_secondary+0x255/0x257 [ 131.274449] ---[ end trace 1151a50552231615 ]--- When we change the system time to a low value like this, the value of timekeeper->offs_real will be a negative value. It seems that the WARN occurs because an hrtimer has been started in the time between the releasing of the timekeeper lock and the IPI call (via a call to on_each_cpu) in clock_was_set() in the do_settimeofday() code. The end result is that a REALTIME_CLOCK timer has been added with softexpires = expires = KTIME_MAX. The hrtimer_interrupt() fires/is called and the loop at kernel/hrtimer.c:1289 is executed. In this loop the code subtracts the clock base's offset (which was set to timekeeper->offs_real in do_settimeofday()) from the current hrtimer_cpu_base->expiry value (which was KTIME_MAX): KTIME_MAX - (a negative value) = overflow A simple check for an overflow can resolve this problem. Using KTIME_MAX instead of the overflow value will result in the hrtimer function being run, and the reprogramming of the timer after that. Cc: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org Reviewed-by: Rik van Riel <riel@redhat.com> Signed-off-by: Prarit Bhargava <prarit@redhat.com> [jstultz: Tweaked commit subject] Signed-off-by: John Stultz <john.stultz@linaro.org>
2013-04-08audit: move kaudit thread start from auditd registration to kaudit initRichard Guy Briggs
The kauditd_thread() task was started only after the auditd userspace daemon registers itself with kaudit. This was fine when only auditd consumed messages from the kaudit netlink unicast socket. With the addition of a multicast group to that socket it is more convenient to have the thread start on init of the kaudit kernel subsystem. Signed-off-by: Richard Guy Briggs <rbriggs@redhat.com> Signed-off-by: Eric Paris <eparis@redhat.com>
2013-04-08audit: flatten kauditd_thread wait queue codeRichard Guy Briggs
The wait queue control code in kauditd_thread() was nested deeper than necessary. The function has been flattened for better legibility. Signed-off-by: Richard Guy Briggs <rbriggs@redhat.com> Signed-off-by: Eric Paris <eparis@redhat.com>
2013-04-08audit: refactor hold queue flushRichard Guy Briggs
The hold queue flush code is an autonomous chunk of code that can be refactored, removed from kauditd_thread() into flush_hold_queue() and flattenned for better legibility. Signed-off-by: Richard Guy Briggs <rbriggs@redhat.com> Signed-off-by: Eric Paris <eparis@redhat.com>
2013-04-08audit: improve GID/EGID comparation logicMatvejchikov Ilya
It is useful to extend GID/EGID comparation logic to be able to match not only the exact EID/EGID values but the group/egroup also. Signed-off-by: Matvejchikov Ilya <matvejchikov@gmail.com> Signed-off-by: Eric Paris <eparis@redhat.com>
2013-04-08PM / reboot: call syscore_shutdown() after disable_nonboot_cpus()Huacai Chen
As commit 40dc166c (PM / Core: Introduce struct syscore_ops for core subsystems PM) say, syscore_ops operations should be carried with one CPU on-line and interrupts disabled. However, after commit f96972f2d (kernel/sys.c: call disable_nonboot_cpus() in kernel_restart()), syscore_shutdown() is called before disable_nonboot_cpus(), so break the rules. We have a MIPS machine with a 8259A PIC, and there is an external timer (HPET) linked at 8259A. Since 8259A has been shutdown too early (by syscore_shutdown()), disable_nonboot_cpus() runs without timer interrupt, so it hangs and reboot fails. This patch call syscore_shutdown() a little later (after disable_nonboot_cpus()) to avoid reboot failure, this is the same way as poweroff does. For consistency, add disable_nonboot_cpus() to kernel_halt(). Signed-off-by: Huacai Chen <chenhc@lemote.com> Cc: <stable@vger.kernel.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-04-08ftrace: Do not call stub functions in control loopSteven Rostedt (Red Hat)
The function tracing control loop used by perf spits out a warning if the called function is not a control function. This is because the control function references a per cpu allocated data structure on struct ftrace_ops that is not allocated for other types of functions. commit 0a016409e42 "ftrace: Optimize the function tracer list loop" Had an optimization done to all function tracing loops to optimize for a single registered ops. Unfortunately, this allows for a slight race when tracing starts or ends, where the stub function might be called after the current registered ops is removed. In this case we get the following dump: root# perf stat -e ftrace:function sleep 1 [ 74.339105] WARNING: at include/linux/ftrace.h:209 ftrace_ops_control_func+0xde/0xf0() [ 74.349522] Hardware name: PRIMERGY RX200 S6 [ 74.357149] Modules linked in: sg igb iTCO_wdt ptp pps_core iTCO_vendor_support i7core_edac dca lpc_ich i2c_i801 coretemp edac_core crc32c_intel mfd_core ghash_clmulni_intel dm_multipath acpi_power_meter pcspk r microcode vhost_net tun macvtap macvlan nfsd kvm_intel kvm auth_rpcgss nfs_acl lockd sunrpc uinput xfs libcrc32c sd_mod crc_t10dif sr_mod cdrom mgag200 i2c_algo_bit drm_kms_helper ttm qla2xxx mptsas ahci drm li bahci scsi_transport_sas mptscsih libata scsi_transport_fc i2c_core mptbase scsi_tgt dm_mirror dm_region_hash dm_log dm_mod [ 74.446233] Pid: 1377, comm: perf Tainted: G W 3.9.0-rc1 #1 [ 74.453458] Call Trace: [ 74.456233] [<ffffffff81062e3f>] warn_slowpath_common+0x7f/0xc0 [ 74.462997] [<ffffffff810fbc60>] ? rcu_note_context_switch+0xa0/0xa0 [ 74.470272] [<ffffffff811041a2>] ? __unregister_ftrace_function+0xa2/0x1a0 [ 74.478117] [<ffffffff81062e9a>] warn_slowpath_null+0x1a/0x20 [ 74.484681] [<ffffffff81102ede>] ftrace_ops_control_func+0xde/0xf0 [ 74.491760] [<ffffffff8162f400>] ftrace_call+0x5/0x2f [ 74.497511] [<ffffffff8162f400>] ? ftrace_call+0x5/0x2f [ 74.503486] [<ffffffff8162f400>] ? ftrace_call+0x5/0x2f [ 74.509500] [<ffffffff810fbc65>] ? synchronize_sched+0x5/0x50 [ 74.516088] [<ffffffff816254d5>] ? _cond_resched+0x5/0x40 [ 74.522268] [<ffffffff810fbc65>] ? synchronize_sched+0x5/0x50 [ 74.528837] [<ffffffff811041a2>] ? __unregister_ftrace_function+0xa2/0x1a0 [ 74.536696] [<ffffffff816254d5>] ? _cond_resched+0x5/0x40 [ 74.542878] [<ffffffff8162402d>] ? mutex_lock+0x1d/0x50 [ 74.548869] [<ffffffff81105c67>] unregister_ftrace_function+0x27/0x50 [ 74.556243] [<ffffffff8111eadf>] perf_ftrace_event_register+0x9f/0x140 [ 74.563709] [<ffffffff816254d5>] ? _cond_resched+0x5/0x40 [ 74.569887] [<ffffffff8162402d>] ? mutex_lock+0x1d/0x50 [ 74.575898] [<ffffffff8111e94e>] perf_trace_destroy+0x2e/0x50 [ 74.582505] [<ffffffff81127ba9>] tp_perf_event_destroy+0x9/0x10 [ 74.589298] [<ffffffff811295d0>] free_event+0x70/0x1a0 [ 74.595208] [<ffffffff8112a579>] perf_event_release_kernel+0x69/0xa0 [ 74.602460] [<ffffffff816254d5>] ? _cond_resched+0x5/0x40 [ 74.608667] [<ffffffff8112a640>] put_event+0x90/0xc0 [ 74.614373] [<ffffffff8112a740>] perf_release+0x10/0x20 [ 74.620367] [<ffffffff811a3044>] __fput+0xf4/0x280 [ 74.625894] [<ffffffff811a31de>] ____fput+0xe/0x10 [ 74.631387] [<ffffffff81083697>] task_work_run+0xa7/0xe0 [ 74.637452] [<ffffffff81014981>] do_notify_resume+0x71/0xb0 [ 74.643843] [<ffffffff8162fa92>] int_signal+0x12/0x17 To fix this a new ftrace_ops flag is added that denotes the ftrace_list_end ftrace_ops stub as just that, a stub. This flag is now checked in the control loop and the function is not called if the flag is set. Thanks to Jovi for not just reporting the bug, but also pointing out where the bug was in the code. Link: http://lkml.kernel.org/r/514A8855.7090402@redhat.com Link: http://lkml.kernel.org/r/1364377499-1900-15-git-send-email-jovi.zhangwei@huawei.com Tested-by: WANG Chao <chaowang@redhat.com> Reported-by: WANG Chao <chaowang@redhat.com> Reported-by: zhangwei(Jovi) <jovi.zhangwei@huawei.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-04-08ftrace: Consistently restore trace function on sysctl enablingJan Kiszka
If we reenable ftrace via syctl, we currently set ftrace_trace_function based on the previous simplistic algorithm. This is inconsistent with what update_ftrace_function does. So better call that helper instead. Link: http://lkml.kernel.org/r/5151D26F.1070702@siemens.com Cc: stable@vger.kernel.org Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-04-08tracing: Fix race with update_max_tr_single and changing tracersSteven Rostedt (Red Hat)
The commit 34600f0e9 "tracing: Fix race with max_tr and changing tracers" fixed the updating of the main buffers with the race of changing tracers, but left out the fix to the updating of just a per cpu buffer. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-04-08sched/cputime: Fix accounting on multi-threaded processesStanislaw Gruszka
Recent commit 6fac4829 ("cputime: Use accessors to read task cputime stats") introduced a bug, where we account many times the cputime of the first thread, instead of cputimes of all the different threads. Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com> Acked-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20130404085740.GA2495@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-04-08lockdep: Remove unnecessary 'hlock_next' variableHong Zhiguo
Signed-off-by: Hong Zhiguo <honkiko@gmail.com> Cc: peterz@infradead.org Link: http://lkml.kernel.org/r/1365058881-4044-1-git-send-email-honkiko@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-04-08idle: Implement generic idle functionThomas Gleixner
All idle functions in arch/* are more or less the same, plus minus a few bugs and extra instrumentation, tickless support and other optional items. Implement a generic idle function which resembles the functionality found in arch/. Provide weak arch_cpu_idle_* functions which can be overridden by the architecture code if needed. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Paul McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Reviewed-by: Cc: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Cc: Magnus Damm <magnus.damm@gmail.com> Link: http://lkml.kernel.org/r/20130321215233.646635455@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2013-04-08idle: Provide a generic entry point for the idle codeThomas Gleixner
For now this calls cpu_idle(), but in the long run we want to move the cpu bringup code to the core and therefor we add a state argument. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Paul McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Reviewed-by: Cc: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Cc: Magnus Damm <magnus.damm@gmail.com> Link: http://lkml.kernel.org/r/20130321215233.583190032@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2013-04-08arch: Consolidate tsk_is_polling()Thomas Gleixner
Move it to a common place. Preparatory patch for implementing set/clear for the idle need_resched poll implementation. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Paul McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Reviewed-by: Cc: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Cc: Magnus Damm <magnus.damm@gmail.com> Link: http://lkml.kernel.org/r/20130321215233.446034505@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2013-04-08sched: Fix typo inside commentViresh Kumar
Fix typo: sched_domains_nume_distance -> sched_domains_numa_distance Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Cc: linaro-kernel@lists.linaro.org Cc: patches@linaro.org Cc: robin.randhawa@arm.com Cc: Steve.Bannister@arm.com Cc: Liviu.Dudau@arm.com Cc: charles.garcia-tobin@arm.com Cc: arvind.chauhan@arm.com Cc: peterz@infradead.org Link: http://lkml.kernel.org/r/cd8084746ac932106d6fa6be388b8f2d6aa9617c.1365159023.git.viresh.kumar@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-04-08ftrace: Fix strncpy() use, use strlcpy() instead of strncpy()Chen Gang
For NUL terminated string we always need to set '\0' at the end. Signed-off-by: Chen Gang <gang.chen@asianux.com> Cc: rostedt@goodmis.org Cc: Frederic Weisbecker <fweisbec@gmail.com> Link: http://lkml.kernel.org/r/516243B7.9020405@asianux.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-04-08perf: Fix strncpy() use, use strlcpy() instead of strncpy()Chen Gang
For NUL terminated string we always need to set '\0' at the end. Signed-off-by: Chen Gang <gang.chen@asianux.com> Cc: rostedt@goodmis.org Cc: Frederic Weisbecker <fweisbec@gmail.com> Link: http://lkml.kernel.org/r/51624254.30301@asianux.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-04-08perf: Fix strncpy() use, always make sure it's NUL terminatedChen Gang
For NUL terminated string, always make sure that there's '\0' at the end. In our case we need a return value, so still use strncpy() and fix up the tail explicitly. (strlcpy() returns the size, not the pointer) Signed-off-by: Chen Gang <gang.chen@asianux.com> Cc: a.p.zijlstra@chello.nl <a.p.zijlstra@chello.nl> Cc: paulus@samba.org <paulus@samba.org> Cc: acme@ghostprotocols.net <acme@ghostprotocols.net> Link: http://lkml.kernel.org/r/51623E0B.7070101@asianux.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-04-08sched/debug: Fix sd->*_idx limit range avoiding overflowlibin
Commit 201c373e8e ("sched/debug: Limit sd->*_idx range on sysctl") was an incomplete bug fix. This patch fixes sd->*_idx limit range to [0 ~ CPU_LOAD_IDX_MAX-1] avoiding array overflow caused by setting sd->*_idx to CPU_LOAD_IDX_MAX on sysctl. Signed-off-by: Libin <huawei.libin@huawei.com> Cc: <jiang.liu@huawei.com> Cc: <guohanjun@huawei.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/51626610.2040607@huawei.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-04-08sched_clock: Prevent 64bit inatomicity on 32bit systemsThomas Gleixner
The sched_clock_remote() implementation has the following inatomicity problem on 32bit systems when accessing the remote scd->clock, which is a 64bit value. CPU0 CPU1 sched_clock_local() sched_clock_remote(CPU0) ... remote_clock = scd[CPU0]->clock read_low32bit(scd[CPU0]->clock) cmpxchg64(scd->clock,...) read_high32bit(scd[CPU0]->clock) While the update of scd->clock is using an atomic64 mechanism, the readout on the remote cpu is not, which can cause completely bogus readouts. It is a quite rare problem, because it requires the update to hit the narrow race window between the low/high readout and the update must go across the 32bit boundary. The resulting misbehaviour is, that CPU1 will see the sched_clock on CPU1 ~4 seconds ahead of it's own and update CPU1s sched_clock value to this bogus timestamp. This stays that way due to the clamping implementation for about 4 seconds until the synchronization with CLOCK_MONOTONIC undoes the problem. The issue is hard to observe, because it might only result in a less accurate SCHED_OTHER timeslicing behaviour. To create observable damage on realtime scheduling classes, it is necessary that the bogus update of CPU1 sched_clock happens in the context of an realtime thread, which then gets charged 4 seconds of RT runtime, which results in the RT throttler mechanism to trigger and prevent scheduling of RT tasks for a little less than 4 seconds. So this is quite unlikely as well. The issue was quite hard to decode as the reproduction time is between 2 days and 3 weeks and intrusive tracing makes it less likely, but the following trace recorded with trace_clock=global, which uses sched_clock_local(), gave the final hint: <idle>-0 0d..30 400269.477150: hrtimer_cancel: hrtimer=0xf7061e80 <idle>-0 0d..30 400269.477151: hrtimer_start: hrtimer=0xf7061e80 ... irq/20-S-587 1d..32 400273.772118: sched_wakeup: comm= ... target_cpu=0 <idle>-0 0dN.30 400273.772118: hrtimer_cancel: hrtimer=0xf7061e80 What happens is that CPU0 goes idle and invokes sched_clock_idle_sleep_event() which invokes sched_clock_local() and CPU1 runs a remote wakeup for CPU0 at the same time, which invokes sched_remote_clock(). The time jump gets propagated to CPU0 via sched_remote_clock() and stays stale on both cores for ~4 seconds. There are only two other possibilities, which could cause a stale sched clock: 1) ktime_get() which reads out CLOCK_MONOTONIC returns a sporadic wrong value. 2) sched_clock() which reads the TSC returns a sporadic wrong value. #1 can be excluded because sched_clock would continue to increase for one jiffy and then go stale. #2 can be excluded because it would not make the clock jump forward. It would just result in a stale sched_clock for one jiffy. After quite some brain twisting and finding the same pattern on other traces, sched_clock_remote() remained the only place which could cause such a problem and as explained above it's indeed racy on 32bit systems. So while on 64bit systems the readout is atomic, we need to verify the remote readout on 32bit machines. We need to protect the local->clock readout in sched_clock_remote() on 32bit as well because an NMI could hit between the low and the high readout, call sched_clock_local() and modify local->clock. Thanks to Siegfried Wulsch for bearing with my debug requests and going through the tedious tasks of running a bunch of reproducer systems to generate the debug information which let me decode the issue. Reported-by: Siegfried Wulsch <Siegfried.Wulsch@rovema.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Link: http://lkml.kernel.org/r/alpine.LFD.2.02.1304051544160.21884@ionos Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org
2013-04-08Merge branch 'for-tip' of ↵Ingo Molnar
git://git.kernel.org/pub/scm/linux/kernel/git/rric/oprofile into perf/core Pull IBM zEnterprise EC12 support patchlet from Robert Richter. Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-04-07cgroup: remove cgroup_lock_is_held()Tejun Heo
We don't want controllers to assume that the information is officially available and do funky things with it. The only user is task_subsys_state_check() which uses it to verify RCU access context. We can move cgroup_lock_is_held() inside CONFIG_PROVE_RCU but that doesn't add meaningful protection compared to conditionally exposing cgroup_mutex. Remove cgroup_lock_is_held(), export cgroup_mutex iff CONFIG_PROVE_RCU and use lockdep_is_held() directly on the mutex in task_subsys_state_check(). While at it, add parentheses around macro arguments in task_subsys_state_check(). Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Li Zefan <lizefan@huawei.com>
2013-04-07cgroup: kill cgroup_[un]lock()Tejun Heo
Now that locking interface is unexported, there's no reason to keep around these thin wrappers. Kill them and use mutex operations directly. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Li Zefan <lizefan@huawei.com>
2013-04-07cgroup: unexport locking interface and cgroup_attach_task()Tejun Heo
Now that all external cgroup_lock() users are gone, we can finally unexport the locking interface and prevent future abuse of cgroup_mutex. Make cgroup_[un]lock() and cgroup_lock_live_group() static. Also, cgroup_attach_task() doesn't have any user left and can't be used without locking interface anyway. Make it static too. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Li Zefan <lizefan@huawei.com>
2013-04-07cgroup: relocate cgroup_lock_live_group() and cgroup_attach_task_all()Tejun Heo
cgroup_lock_live_group() and cgroup_attach_task() are scheduled to be made static. Relocate the former and cgroup_attach_task_all() so that we don't need forward declarations. This patch is pure relocation. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Li Zefan <lizefan@huawei.com>
2013-04-07cgroup, cpuset: replace move_member_tasks_to_cpuset() with ↵Tejun Heo
cgroup_transfer_tasks() When a cpuset becomes empty (no CPU or memory), its tasks are transferred with the nearest ancestor with execution resources. This is implemented using cgroup_scan_tasks() with a callback which grabs cgroup_mutex and invokes cgroup_attach_task() on each task. Both cgroup_mutex and cgroup_attach_task() are scheduled to be unexported. Implement cgroup_transfer_tasks() in cgroup proper which is essentially the same as move_member_tasks_to_cpuset() except that it takes cgroups instead of cpusets and @to comes before @from like normal functions with those arguments, and replace move_member_tasks_to_cpuset() with it. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Li Zefan <lizefan@huawei.com>
2013-04-05PM / sleep: invalidate TEST_CPUS and TEST_CORE support for freeze stateZhang Rui
freeze state is a software suspend state that does not run into low-level platform callbacks which may interact with BIOS. And freeze state does not need to disable the processors. But the current pm_test support misleads users because users can enter freeze state with pm_test set to TEST_CPUS/TEST_CORE, while this pm_test setting never takes actions. So, invalidate TEST_CPUS/TEST_CORE for freeze state in this patch. Then users will get an error instead, when trying to enter freeze state with pm_test mode set to TEST_CPUS/TEST_CORE. Signed-off-by: Zhang Rui <rui.zhang@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-04-05PM / sleep: add TEST_PLATFORM support for freeze stateZhang Rui
Invoke freeze_enter() after suspend_test(TEST_PLATFORM) being invoked. So when setting /sys/power/pm_test to "platform", it can be used to check if freeze state is working well after all devices are suspended and before processors are blocked, Signed-off-by: Zhang Rui <rui.zhang@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-04-05Merge tag 'drm-intel-next-2013-03-23' of ↵Dave Airlie
git://people.freedesktop.org/~danvet/drm-intel into drm-next Daniel writes: Highlights: - Imre's for_each_sg_pages rework (now also with the stolen mem backed case fixed with a hack) plus the drm prime sg list coalescing patch from Rahul Sharma. I have some follow-up cleanups pending, already acked by Andrew Morton. - Some prep-work for the crazy no-pch/display-less platform by Ben. - Some vlv patches, by far not all (Jesse et al). - Clean up the HDMI/SDVO #define confusion (Paulo) - gen2-4 vblank fixes from Ville. - Unclaimed register warning fixes for hsw (Paulo). More still to come ... - Complete pageflips which have been stuck in a gpu hang, should prevent stuck gl compositors (Ville). - pm patches for vt-switchless resume (Jesse). Note that the i915 enabling is not (yet) included, that took a bit longer to settle. PM patches are acked by Rafael Wysocki. - Minor fixlets all over from various people. * tag 'drm-intel-next-2013-03-23' of git://people.freedesktop.org/~danvet/drm-intel: (79 commits) drm/i915: Implement WaSwitchSolVfFArbitrationPriority drm/i915: Set the VIC in AVI infoframe for SDVO drm/i915: Kill a strange comment about DPMS functions drm/i915: Correct sandybrige overclocking drm/i915: Introduce GEN7_FEATURES for device info drm/i915: Move num_pipes to intel info drm/i915: fixup pd vs pt confusion in gen6 ppgtt code style nit: Align function parameter continuation properly. drm/i915: VLV doesn't have HDMI on port C drm/i915: DSPFW and BLC regs are in the display offset range drm/i915: set conservative clock gating values on VLV v2 drm/i915: fix WaDisablePSDDualDispatchEnable on VLV v2 drm/i915: add more VLV IDs drm/i915: use VLV DIP routines on VLV v2 drm/i915: add media well to VLV force wake routines v2 drm/i915: don't use plane pipe select on VLV drm: modify pages_to_sg prime helper to create optimized SG table drm/i915: use for_each_sg_page for setting up the gtt ptes drm/i915: create compact dma scatter lists for gem objects drm/i915: handle walking compact dma scatter lists ...
2013-04-04timekeeping: Shorten seq_count regionThomas Gleixner
Shorten the seqcount write hold region to the actual update of the timekeeper and the related data (e.g vsyscall). On a contemporary x86 system this reduces the maximum latencies on Preempt-RT from 8us to 4us on the non-timekeeping cores. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: John Stultz <john.stultz@linaro.org>
2013-04-04timekeeping: Implement a shadow timekeeperThomas Gleixner
Use the shadow timekeeper to do the update_wall_time() adjustments and then copy it over to the real timekeeper. Keep the shadow timekeeper in sync when updating stuff outside of update_wall_time(). This allows us to limit the timekeeper_seq hold time to the update of the real timekeeper and the vsyscall data in the next patch. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: John Stultz <john.stultz@linaro.org>
2013-04-04timekeeping: Delay update of clock->cycle_lastThomas Gleixner
For calculating the new timekeeper values store the new cycle_last value in the timekeeper and update the clock->cycle_last just when we actually update the new values. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: John Stultz <john.stultz@linaro.org>
2013-04-04timekeeping: Store cycle_last value in timekeeper struct as wellThomas Gleixner
For implementing a shadow timekeeper and a split calculation/update region we need to store the cycle_last value in the timekeeper and update the value in the clocksource struct only in the update region. Add the extra storage to the timekeeper. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: John Stultz <john.stultz@linaro.org>
2013-04-04ntp: Remove ntp_lock, using the timekeeping locks to protect ntp stateJohn Stultz
In order to properly handle the NTP state in future changes to the timekeeping lock management, this patch moves the management of all of the ntp state under the timekeeping locks. This allows us to remove the ntp_lock. Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Richard Cochran <richardcochran@gmail.com> Cc: Prarit Bhargava <prarit@redhat.com> Signed-off-by: John Stultz <john.stultz@linaro.org>
2013-04-04timekeeping: Simplify tai updating from do_adjtimexJohn Stultz
Since we are taking the timekeeping locks, just go ahead and update any tai change directly, rather then dropping the lock and calling a function that will just take it again. Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Richard Cochran <richardcochran@gmail.com> Cc: Prarit Bhargava <prarit@redhat.com> Signed-off-by: John Stultz <john.stultz@linaro.org>
2013-04-04timekeeping: Hold timekeepering locks in do_adjtimex and hardppsJohn Stultz
In moving the NTP state to be protected by the timekeeping locks, be sure to acquire the timekeeping locks prior to calling ntp functions. Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Richard Cochran <richardcochran@gmail.com> Cc: Prarit Bhargava <prarit@redhat.com> Signed-off-by: John Stultz <john.stultz@linaro.org>
2013-04-04timekeeping: Move ADJ_SETOFFSET to top level do_adjtimex()John Stultz
Since ADJ_SETOFFSET adjusts the timekeeping state, process it as part of the top level do_adjtimex() function in timekeeping.c. This avoids deadlocks that could occur once we change the ntp locking rules. Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Richard Cochran <richardcochran@gmail.com> Cc: Prarit Bhargava <prarit@redhat.com> Signed-off-by: John Stultz <john.stultz@linaro.org>
2013-04-04ntp: Rework do_adjtimex to take timespec and tai argumentsJohn Stultz
In order to change the locking rules, we need to provide the timespec and tai values rather then having the ntp logic acquire these values itself. Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Richard Cochran <richardcochran@gmail.com> Cc: Prarit Bhargava <prarit@redhat.com> Signed-off-by: John Stultz <john.stultz@linaro.org>
2013-04-04ntp: Move timex validation to timekeeping do_adjtimex call.John Stultz
Move logic that does not need the ntp state to be done in the timekeeping do_adjtimex() call. Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Richard Cochran <richardcochran@gmail.com> Cc: Prarit Bhargava <prarit@redhat.com> Signed-off-by: John Stultz <john.stultz@linaro.org>
2013-04-04ntp: Move do_adjtimex() and hardpps() functions to timekeeping.cJohn Stultz
In preparation for changing the ntp locking rules, move do_adjtimex and hardpps accessor functions to timekeeping.c, but keep the code logic in ntp.c. This patch also introduces a ntp_internal.h file so timekeeping specific interfaces of ntp.c can be more limitedly shared with timekeeping.c. Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Richard Cochran <richardcochran@gmail.com> Cc: Prarit Bhargava <prarit@redhat.com> Signed-off-by: John Stultz <john.stultz@linaro.org>
2013-04-04ntp: Split out timex validation from do_adjtimexJohn Stultz
Split out the timex validation done in do_adjtimex into a separate function. This will help simplify logic in following patches. Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Richard Cochran <richardcochran@gmail.com> Cc: Prarit Bhargava <prarit@redhat.com> Signed-off-by: John Stultz <john.stultz@linaro.org>
2013-04-04workqueue: avoid false negative WARN_ON() in destroy_workqueue()Lai Jiangshan
destroy_workqueue() performs several sanity checks before proceeding with destruction of a workqueue. One of the checks verifies that refcnt of each pwq (pool_workqueue) is over 1 as at that point there should be no in-flight work items and the only holder of pwq refs is the workqueue itself. This worked fine as a workqueue used to hold only one reference to its pwqs; however, since 4c16bd327c ("workqueue: implement NUMA affinity for unbound workqueues"), a workqueue may hold multiple references to its default pwq triggering this sanity check spuriously. Fix it by not triggering the pwq->refcnt assertion on default pwqs. An example spurious WARN trigger follows. WARNING: at kernel/workqueue.c:4201 destroy_workqueue+0x6a/0x13e() Hardware name: 4286C12 Modules linked in: sdhci_pci sdhci mmc_core usb_storage i915 drm_kms_helper drm i2c_algo_bit i2c_core video Pid: 361, comm: umount Not tainted 3.9.0-rc5+ #29 Call Trace: [<c04314a7>] warn_slowpath_common+0x7c/0x93 [<c04314e0>] warn_slowpath_null+0x22/0x24 [<c044796a>] destroy_workqueue+0x6a/0x13e [<c056dc01>] ext4_put_super+0x43/0x2c4 [<c04fb7b8>] generic_shutdown_super+0x4b/0xb9 [<c04fb848>] kill_block_super+0x22/0x60 [<c04fb960>] deactivate_locked_super+0x2f/0x56 [<c04fc41b>] deactivate_super+0x2e/0x31 [<c050f1e6>] mntput_no_expire+0x103/0x108 [<c050fdce>] sys_umount+0x2a2/0x2c4 [<c050fe0e>] sys_oldumount+0x1e/0x20 [<c085ba4d>] sysenter_do_call+0x12/0x38 tj: Rewrote description. Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Fengguang Wu <fengguang.wu@intel.com>
2013-04-04uprobes: Change write_opcode() to use copy_*page()Oleg Nesterov
Change write_opcode() to use copy_highpage() + copy_to_page() and simplify the code. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Anton Arapov <anton@redhat.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
2013-04-04uprobes: Introduce copy_to_page()Oleg Nesterov
Extract the kmap_atomic/memcpy/kunmap_atomic code from xol_get_insn_slot() into the new simple helper, copy_to_page(). It will have more users soon. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Anton Arapov <anton@redhat.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
2013-04-04uprobes: Kill the unnecesary filp != NULL check in __copy_insn()Oleg Nesterov
__copy_insn(filp) can only be called after valid_vma() returns T, vma->vm_file passed as "filp" can not be NULL. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Anton Arapov <anton@redhat.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
2013-04-04uprobes: Change __copy_insn() to use copy_from_page()Oleg Nesterov
Change __copy_insn() to use copy_from_page() and simplify the code. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Anton Arapov <anton@redhat.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
2013-04-04uprobes: Turn copy_opcode() into copy_from_page()Oleg Nesterov
No functional changes. Rename copy_opcode() into copy_from_page() and add the new "int len" argument to make it more more generic for the new users. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Anton Arapov <anton@redhat.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
2013-04-04uprobes: Add trap variant helperAnanth N Mavinakayanahalli
Some architectures like powerpc have multiple variants of the trap instruction. Introduce an additional helper is_trap_insn() for run-time handling of non-uprobe traps on such architectures. While there, change is_swbp_at_addr() to is_trap_at_addr() for reading clarity. With this change, the uprobe registration path will supercede any trap instruction inserted at the requested location, while taking care of delivering the SIGTRAP for cases where the trap notification came in for an address without a uprobe. See [1] for a more detailed explanation. [1] https://lists.ozlabs.org/pipermail/linuxppc-dev/2013-March/104771.html This change was suggested by Oleg Nesterov. Signed-off-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Signed-off-by: Oleg Nesterov <oleg@redhat.com>
2013-04-04uprobes: Use file_inode()Oleg Nesterov
Cleanup. Now that we have f_inode/file_inode() we can use it instead of vm_file->f_mapping->host. This should not make any difference for uprobes, but in theory this change is more correct. We use this inode as a key, to compare it with uprobe->inode set by uprobe_register(inode), and the caller uses d_inode. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
2013-04-03cgroup: remove unused parameter in cgroup_task_migrate().Kevin Wilson
This patch removes unused parameter from cgroup_task_migrate(). Signed-off-by: Kevin Wilson <wkevils@gmail.com> Acked-by: Acked-by: Li Zefan <lizefan@huawei.com> Signed-off-by: Tejun Heo <tj@kernel.org>