- 04 2月, 2015 2 次提交
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由 Peter Zijlstra 提交于
There have been a few reported issues wrt. the lack of locking around changing event->ctx. This patch tries to address those. It avoids the whole rwsem thing; and while it appears to work, please give it some thought in review. What I did fail at is sensible runtime checks on the use of event->ctx, the RCU use makes it very hard. Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/20150123125834.209535886@infradead.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Peter Zijlstra 提交于
Add a few WARN()s to catch things that should never happen. Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/20150123125834.150481799@infradead.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>
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- 02 2月, 2015 1 次提交
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由 Linus Torvalds 提交于
Commit 8eb23b9f ("sched: Debug nested sleeps") added code to report on nested sleep conditions, which we generally want to avoid because the inner sleeping operation can re-set the thread state to TASK_RUNNING, but that will then cause the outer sleep loop not actually sleep when it calls schedule. However, that's actually valid traditional behavior, with the inner sleep being some fairly rare case (like taking a sleeping lock that normally doesn't actually need to sleep). And the debug code would actually change the state of the task to TASK_RUNNING internally, which makes that kind of traditional and working code not work at all, because now the nested sleep doesn't just sometimes cause the outer one to not block, but will cause it to happen every time. In particular, it will cause the cardbus kernel daemon (pccardd) to basically busy-loop doing scheduling, converting a laptop into a heater, as reported by Bruno Prémont. But there may be other legacy uses of that nested sleep model in other drivers that are also likely to never get converted to the new model. This fixes both cases: - don't set TASK_RUNNING when the nested condition happens (note: even if WARN_ONCE() only _warns_ once, the return value isn't whether the warning happened, but whether the condition for the warning was true. So despite the warning only happening once, the "if (WARN_ON(..))" would trigger for every nested sleep. - in the cases where we knowingly disable the warning by using "sched_annotate_sleep()", don't change the task state (that is used for all core scheduling decisions), instead use '->task_state_change' that is used for the debugging decision itself. (Credit for the second part of the fix goes to Oleg Nesterov: "Can't we avoid this subtle change in behaviour DEBUG_ATOMIC_SLEEP adds?" with the suggested change to use 'task_state_change' as part of the test) Reported-and-bisected-by: NBruno Prémont <bonbons@linux-vserver.org> Tested-by: NRafael J Wysocki <rjw@rjwysocki.net> Acked-by: NOleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de>, Cc: Ilya Dryomov <ilya.dryomov@inktank.com>, Cc: Mike Galbraith <umgwanakikbuti@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Peter Hurley <peter@hurleysoftware.com>, Cc: Davidlohr Bueso <dave@stgolabs.net>, Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 28 1月, 2015 1 次提交
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由 Peter Zijlstra 提交于
The fix from 9fc81d87 ("perf: Fix events installation during moving group") was incomplete in that it failed to recognise that creating a group with events for different CPUs is semantically broken -- they cannot be co-scheduled. Furthermore, it leads to real breakage where, when we create an event for CPU Y and then migrate it to form a group on CPU X, the code gets confused where the counter is programmed -- triggered in practice as well by me via the perf fuzzer. Fix this by tightening the rules for creating groups. Only allow grouping of counters that can be co-scheduled in the same context. This means for the same task and/or the same cpu. Fixes: 9fc81d87 ("perf: Fix events installation during moving group") Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/20150123125834.090683288@infradead.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>
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- 27 1月, 2015 1 次提交
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由 Alexei Starovoitov 提交于
BUG: sleeping function called from invalid context at mm/memory.c:3732 in_atomic(): 0, irqs_disabled(): 0, pid: 671, name: test_maps 1 lock held by test_maps/671: #0: (rcu_read_lock){......}, at: [<0000000000264190>] map_lookup_elem+0xe8/0x260 Call Trace: ([<0000000000115b7e>] show_trace+0x12e/0x150) [<0000000000115c40>] show_stack+0xa0/0x100 [<00000000009b163c>] dump_stack+0x74/0xc8 [<000000000017424a>] ___might_sleep+0x23a/0x248 [<00000000002b58e8>] might_fault+0x70/0xe8 [<0000000000264230>] map_lookup_elem+0x188/0x260 [<0000000000264716>] SyS_bpf+0x20e/0x840 Fix it by allocating temporary buffer to store map element value. Fixes: db20fd2b ("bpf: add lookup/update/delete/iterate methods to BPF maps") Reported-by: NMichael Holzheu <holzheu@linux.vnet.ibm.com> Signed-off-by: NAlexei Starovoitov <ast@plumgrid.com> Acked-by: NDaniel Borkmann <dborkman@redhat.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 23 1月, 2015 1 次提交
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由 Dave Hansen 提交于
Description from Michael Kerrisk. He suggested an identical patch to one I had already coded up and tested. commit fe3d197f "x86, mpx: On-demand kernel allocation of bounds tables" added two new prctl() operations, PR_MPX_ENABLE_MANAGEMENT and PR_MPX_DISABLE_MANAGEMENT. However, no checks were included to ensure that unused arguments are zero, as is done in many existing prctl()s and as should be done for all new prctl()s. This patch adds the required checks. Suggested-by: NAndy Lutomirski <luto@amacapital.net> Suggested-by: NMichael Kerrisk <mtk.manpages@gmail.com> Signed-off-by: NDave Hansen <dave.hansen@linux.intel.com> Cc: Dave Hansen <dave@sr71.net> Link: http://lkml.kernel.org/r/20150108223022.7F56FD13@viggo.jf.intel.comSigned-off-by: NThomas Gleixner <tglx@linutronix.de>
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- 22 1月, 2015 2 次提交
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由 Johannes Weiner 提交于
Since b2052564 ("mm: memcontrol: continue cache reclaim from offlined groups"), re-mounting the memory controller after using it is very likely to hang. The cgroup core assumes that any remaining references after deleting a cgroup are temporary in nature, and synchroneously waits for them, but the above-mentioned commit has left-over page cache pin its css until it is reclaimed naturally. That being said, swap entries and charged kernel memory have been doing the same indefinite pinning forever, the bug is just more likely to trigger with left-over page cache. Reparenting kernel memory is highly impractical, which leaves changing the cgroup assumptions to reflect this: once a controller has been mounted and used, it has internal state that is independent from mount and cgroup lifetime. It can be unmounted and remounted, but it can't be reconfigured during subsequent mounts. Don't offline the controller root as long as there are any children, dead or alive. A remount will no longer wait for these old references to drain, it will simply mount the persistent controller state again. Reported-by: N"Suzuki K. Poulose" <Suzuki.Poulose@arm.com> Reported-by: NWill Deacon <will.deacon@arm.com> Signed-off-by: NJohannes Weiner <hannes@cmpxchg.org> Signed-off-by: NTejun Heo <tj@kernel.org>
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由 Rusty Russell 提交于
James Bottomley points out that it will be -1 during unload. It's only used for diagnostics, so let's not hide that as it could be a clue as to what's gone wrong. Cc: Jason Wessel <jason.wessel@windriver.com> Acked-and-documention-added-by: NJames Bottomley <James.Bottomley@HansenPartnership.com> Reviewed-by: NMasami Hiramatsu <maasami.hiramatsu.pt@hitachi.com> Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
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- 20 1月, 2015 4 次提交
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由 Rusty Russell 提交于
The kallsyms routines (module_symbol_name, lookup_module_* etc) disable preemption to walk the modules rather than taking the module_mutex: this is because they are used for symbol resolution during oopses. This works because there are synchronize_sched() and synchronize_rcu() in the unload and failure paths. However, there's one case which doesn't have that: the normal case where module loading succeeds, and we free the init section. We don't want a synchronize_rcu() there, because it would slow down module loading: this bug was introduced in 2009 to speed module loading in the first place. Thus, we want to do the free in an RCU callback. We do this in the simplest possible way by allocating a new rcu_head: if we put it in the module structure we'd have to worry about that getting freed. Reported-by: NRui Xiang <rui.xiang@huawei.com> Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
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由 Rusty Russell 提交于
Nothing needs the module pointer any more, and the next patch will call it from RCU, where the module itself might no longer exist. Removing the arg is the safest approach. This just codifies the use of the module_alloc/module_free pattern which ftrace and bpf use. Signed-off-by: NRusty Russell <rusty@rustcorp.com.au> Acked-by: NAlexei Starovoitov <ast@kernel.org> Cc: Mikael Starvik <starvik@axis.com> Cc: Jesper Nilsson <jesper.nilsson@axis.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Ley Foon Tan <lftan@altera.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Chris Metcalf <cmetcalf@ezchip.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: x86@kernel.org Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: linux-cris-kernel@axis.com Cc: linux-kernel@vger.kernel.org Cc: linux-mips@linux-mips.org Cc: nios2-dev@lists.rocketboards.org Cc: linuxppc-dev@lists.ozlabs.org Cc: sparclinux@vger.kernel.org Cc: netdev@vger.kernel.org
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由 Rusty Russell 提交于
Archs have been abusing module_free() to clean up their arch-specific allocations. Since module_free() is also (ab)used by BPF and trace code, let's keep it to simple allocations, and provide a hook called before that. This means that avr32, ia64, parisc and s390 no longer need to implement their own module_free() at all. avr32 doesn't need module_finalize() either. Signed-off-by: NRusty Russell <rusty@rustcorp.com.au> Cc: Chris Metcalf <cmetcalf@ezchip.com> Cc: Haavard Skinnemoen <hskinnemoen@gmail.com> Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no> Cc: Tony Luck <tony.luck@intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> Cc: Helge Deller <deller@gmx.de> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: linux-kernel@vger.kernel.org Cc: linux-ia64@vger.kernel.org Cc: linux-parisc@vger.kernel.org Cc: linux-s390@vger.kernel.org
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由 Rusty Russell 提交于
ignore_lockdep is uninitialized, and sysfs_attr_init() doesn't initialize it, so memset to 0. Reported-by: NHuang Ying <ying.huang@intel.com> Cc: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
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- 17 1月, 2015 2 次提交
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由 Louis Langholtz 提交于
Avoid overflow possibility. [ The overflow is purely theoretical, since this is used for memory ranges that aren't even close to using the full 64 bits, but this is the right thing to do regardless. - Linus ] Signed-off-by: NLouis Langholtz <lou_langholtz@me.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Peter Anvin <hpa@linux.intel.com> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Tejun Heo 提交于
A worker_pool's forward progress is guaranteed by the fact that the last idle worker assumes the manager role to create more workers and summon the rescuers if creating workers doesn't succeed in timely manner before proceeding to execute work items. This manager role is implemented in manage_workers(), which indicates whether the worker may proceed to work item execution with its return value. This is necessary because multiple workers may contend for the manager role, and, if there already is a manager, others should proceed to work item execution. Unfortunately, the function also indicates that the worker may proceed to work item execution if need_to_create_worker() is false at the head of the function. need_to_create_worker() tests the following conditions. pending work items && !nr_running && !nr_idle The first and third conditions are protected by pool->lock and thus won't change while holding pool->lock; however, nr_running can change asynchronously as other workers block and resume and while it's likely to be zero, as someone woke this worker up in the first place, some other workers could have become runnable inbetween making it non-zero. If this happens, manage_worker() could return false even with zero nr_idle making the worker, the last idle one, proceed to execute work items. If then all workers of the pool end up blocking on a resource which can only be released by a work item which is pending on that pool, the whole pool can deadlock as there's no one to create more workers or summon the rescuers. This patch fixes the problem by removing the early exit condition from maybe_create_worker() and making manage_workers() return false iff there's already another manager, which ensures that the last worker doesn't start executing work items. We can leave the early exit condition alone and just ignore the return value but the only reason it was put there is because the manage_workers() used to perform both creations and destructions of workers and thus the function may be invoked while the pool is trying to reduce the number of workers. Now that manage_workers() is called only when more workers are needed, the only case this early exit condition is triggered is rare race conditions rendering it pointless. Tested with simulated workload and modified workqueue code which trigger the pool deadlock reliably without this patch. Signed-off-by: NTejun Heo <tj@kernel.org> Reported-by: NEric Sandeen <sandeen@sandeen.net> Link: http://lkml.kernel.org/g/54B019F4.8030009@sandeen.net Cc: Dave Chinner <david@fromorbit.com> Cc: Lai Jiangshan <laijs@cn.fujitsu.com> Cc: stable@vger.kernel.org
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- 15 1月, 2015 4 次提交
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由 Steven Rostedt (Red Hat) 提交于
Commit 5f893b26 "tracing: Move enabling tracepoints to just after rcu_init()" broke the enabling of system call events from the command line. The reason was that the enabling of command line trace events was moved before PID 1 started, and the syscall tracepoints require that all tasks have the TIF_SYSCALL_TRACEPOINT flag set. But the swapper task (pid 0) is not part of that. Since the swapper task is the only task that is running at this early in boot, no task gets the flag set, and the tracepoint never gets reached. Instead of setting the swapper task flag (there should be no reason to do that), re-enabled trace events again after the init thread (PID 1) has been started. It requires disabling all command line events and re-enabling them, as just enabling them again will not reset the logic to set the TIF_SYSCALL_TRACEPOINT flag, as the syscall tracepoint will be fooled into thinking that it was already set, and wont try setting it again. For this reason, we must first disable it and re-enable it. Link: http://lkml.kernel.org/r/1421188517-18312-1-git-send-email-mpe@ellerman.id.au Link: http://lkml.kernel.org/r/20150115040506.216066449@goodmis.orgReported-by: NMichael Ellerman <mpe@ellerman.id.au> Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
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由 Steven Rostedt (Red Hat) 提交于
trace_init() calls init_ftrace_syscalls() and then calls trace_event_init() which also calls init_ftrace_syscalls(). It makes more sense to only call it from trace_event_init(). Calling it twice wastes memory, as it allocates the syscall events twice, and loses the first copy of it. Link: http://lkml.kernel.org/r/54AF53BD.5070303@huawei.com Link: http://lkml.kernel.org/r/20150115040505.930398632@goodmis.orgReported-by: NWang Nan <wangnan0@huawei.com> Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
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由 Steven Rostedt (Red Hat) 提交于
Using just the filter for checking for trampolines or regs is not enough when updating the code against the records that represent all functions. Both the filter hash and the notrace hash need to be checked. To trigger this bug (using trace-cmd and perf): # perf probe -a do_fork # trace-cmd start -B foo -e probe # trace-cmd record -p function_graph -n do_fork sleep 1 The trace-cmd record at the end clears the filter before it disables function_graph tracing and then that causes the accounting of the ftrace function records to become incorrect and causes ftrace to bug. Link: http://lkml.kernel.org/r/20150114154329.358378039@goodmis.org Cc: stable@vger.kernel.org [ still need to switch old_hash_ops to old_ops_hash ] Reviewed-by: NMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
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由 Steven Rostedt (Red Hat) 提交于
As the set_ftrace_filter affects both the function tracer as well as the function graph tracer, the ops that represent each have a shared ftrace_ops_hash structure. This allows both to be updated when the filter files are updated. But if function graph is enabled and the global_ops (function tracing) ops is not, then it is possible that the filter could be changed without the update happening for the function graph ops. This will cause the changes to not take place and may even cause a ftrace_bug to occur as it could mess with the trampoline accounting. The solution is to check if the ops uses the shared global_ops filter and if the ops itself is not enabled, to check if there's another ops that is enabled and also shares the global_ops filter. In that case, the modification still needs to be executed. Link: http://lkml.kernel.org/r/20150114154329.055980438@goodmis.org Cc: stable@vger.kernel.org # 3.17+ Reviewed-by: NMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
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- 14 1月, 2015 1 次提交
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由 Peter Zijlstra (Intel) 提交于
Both Linus (most recent) and Steve (a while ago) reported that perf related callbacks have massive stack bloat. The problem is that software events need a pt_regs in order to properly report the event location and unwind stack. And because we could not assume one was present we allocated one on stack and filled it with minimal bits required for operation. Now, pt_regs is quite large, so this is undesirable. Furthermore it turns out that most sites actually have a pt_regs pointer available, making this even more onerous, as the stack space is pointless waste. This patch addresses the problem by observing that software events have well defined nesting semantics, therefore we can use static per-cpu storage instead of on-stack. Linus made the further observation that all but the scheduler callers of perf_sw_event() have a pt_regs available, so we change the regular perf_sw_event() to require a valid pt_regs (where it used to be optional) and add perf_sw_event_sched() for the scheduler. We have a scheduler specific call instead of a more generic _noregs() like construct because we can assume non-recursion from the scheduler and thereby simplify the code further (_noregs would have to put the recursion context call inline in order to assertain which __perf_regs element to use). One last note on the implementation of perf_trace_buf_prepare(); we allow .regs = NULL for those cases where we already have a pt_regs pointer available and do not need another. Reported-by: NLinus Torvalds <torvalds@linux-foundation.org> Reported-by: NSteven Rostedt <rostedt@goodmis.org> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Javi Merino <javi.merino@arm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Petr Mladek <pmladek@suse.cz> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Tom Zanussi <tom.zanussi@linux.intel.com> Cc: Vaibhav Nagarnaik <vnagarnaik@google.com> Link: http://lkml.kernel.org/r/20141216115041.GW3337@twins.programming.kicks-ass.netSigned-off-by: NIngo Molnar <mingo@kernel.org>
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- 09 1月, 2015 7 次提交
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由 Chris Wilson 提交于
Currently if DEBUG_MUTEXES is enabled, the mutex->owner field is only cleared iff debug_locks is active. This exposes a race to other users of the field where the mutex->owner may be still set to a stale value, potentially upsetting mutex_spin_on_owner() among others. References: https://bugs.freedesktop.org/show_bug.cgi?id=87955Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Acked-by: NDavidlohr Bueso <dave@stgolabs.net> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/1420540175-30204-1-git-send-email-chris@chris-wilson.co.ukSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Tetsuo Handa 提交于
When alloc_fair_sched_group() in sched_create_group() fails, free_sched_group() is called, and free_fair_sched_group() is called by free_sched_group(). Since destroy_cfs_bandwidth() is called by free_fair_sched_group() without calling init_cfs_bandwidth(), RCU stall occurs at hrtimer_cancel(): INFO: rcu_sched self-detected stall on CPU { 1} (t=60000 jiffies g=13074 c=13073 q=0) Task dump for CPU 1: (fprintd) R running task 0 6249 1 0x00000088 ... Call Trace: <IRQ> [<ffffffff81094988>] sched_show_task+0xa8/0x110 [<ffffffff81097acd>] dump_cpu_task+0x3d/0x50 [<ffffffff810c3a80>] rcu_dump_cpu_stacks+0x90/0xd0 [<ffffffff810c7751>] rcu_check_callbacks+0x491/0x700 [<ffffffff810cbf2b>] update_process_times+0x4b/0x80 [<ffffffff810db046>] tick_sched_handle.isra.20+0x36/0x50 [<ffffffff810db0a2>] tick_sched_timer+0x42/0x70 [<ffffffff810ccb19>] __run_hrtimer+0x69/0x1a0 [<ffffffff810db060>] ? tick_sched_handle.isra.20+0x50/0x50 [<ffffffff810ccedf>] hrtimer_interrupt+0xef/0x230 [<ffffffff810452cb>] local_apic_timer_interrupt+0x3b/0x70 [<ffffffff8164a465>] smp_apic_timer_interrupt+0x45/0x60 [<ffffffff816485bd>] apic_timer_interrupt+0x6d/0x80 <EOI> [<ffffffff810cc588>] ? lock_hrtimer_base.isra.23+0x18/0x50 [<ffffffff81193cf1>] ? __kmalloc+0x211/0x230 [<ffffffff810cc9d2>] hrtimer_try_to_cancel+0x22/0xd0 [<ffffffff81193cf1>] ? __kmalloc+0x211/0x230 [<ffffffff810ccaa2>] hrtimer_cancel+0x22/0x30 [<ffffffff810a3cb5>] free_fair_sched_group+0x25/0xd0 [<ffffffff8108df46>] free_sched_group+0x16/0x40 [<ffffffff810971bb>] sched_create_group+0x4b/0x80 [<ffffffff810aa383>] sched_autogroup_create_attach+0x43/0x1c0 [<ffffffff8107dc9c>] sys_setsid+0x7c/0x110 [<ffffffff81647729>] system_call_fastpath+0x12/0x17 Check whether init_cfs_bandwidth() was called before calling destroy_cfs_bandwidth(). Signed-off-by: NTetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> [ Move the check into destroy_cfs_bandwidth() to aid compilability. ] Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Paul Turner <pjt@google.com> Cc: Ben Segall <bsegall@google.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/201412252210.GCC30204.SOMVFFOtQJFLOH@I-love.SAKURA.ne.jpSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Luca Abeni 提交于
The dl_runtime_exceeded() function is supposed to ckeck if a SCHED_DEADLINE task must be throttled, by checking if its current runtime is <= 0. However, it also checks if the scheduling deadline has been missed (the current time is larger than the current scheduling deadline), further decreasing the runtime if this happens. This "double accounting" is wrong: - In case of partitioned scheduling (or single CPU), this happens if task_tick_dl() has been called later than expected (due to small HZ values). In this case, the current runtime is also negative, and replenish_dl_entity() can take care of the deadline miss by recharging the current runtime to a value smaller than dl_runtime - In case of global scheduling on multiple CPUs, scheduling deadlines can be missed even if the task did not consume more runtime than expected, hence penalizing the task is wrong This patch fix this problem by throttling a SCHED_DEADLINE task only when its runtime becomes negative, and not modifying the runtime Signed-off-by: NLuca Abeni <luca.abeni@unitn.it> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Acked-by: NJuri Lelli <juri.lelli@gmail.com> Cc: <stable@vger.kernel.org> Cc: Dario Faggioli <raistlin@linux.it> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/1418813432-20797-3-git-send-email-luca.abeni@unitn.itSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Luca Abeni 提交于
According to global EDF, tasks should be migrated between runqueues without checking if their scheduling deadlines and runtimes are valid. However, SCHED_DEADLINE currently performs such a check: a migration happens doing: deactivate_task(rq, next_task, 0); set_task_cpu(next_task, later_rq->cpu); activate_task(later_rq, next_task, 0); which ends up calling dequeue_task_dl(), setting the new CPU, and then calling enqueue_task_dl(). enqueue_task_dl() then calls enqueue_dl_entity(), which calls update_dl_entity(), which can modify scheduling deadline and runtime, breaking global EDF scheduling. As a result, some of the properties of global EDF are not respected: for example, a taskset {(30, 80), (40, 80), (120, 170)} scheduled on two cores can have unbounded response times for the third task even if 30/80+40/80+120/170 = 1.5809 < 2 This can be fixed by invoking update_dl_entity() only in case of wakeup, or if this is a new SCHED_DEADLINE task. Signed-off-by: NLuca Abeni <luca.abeni@unitn.it> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Acked-by: NJuri Lelli <juri.lelli@gmail.com> Cc: <stable@vger.kernel.org> Cc: Dario Faggioli <raistlin@linux.it> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/1418813432-20797-2-git-send-email-luca.abeni@unitn.itSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Yuyang Du 提交于
In effective_load, we have (long w * unsigned long tg->shares) / long W, when w is negative, it is cast to unsigned long and hence the product is insanely large. Fix this by casting tg->shares to long. Reported-by: NSasha Levin <sasha.levin@oracle.com> Signed-off-by: NYuyang Du <yuyang.du@intel.com> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Dave Jones <davej@redhat.com> Cc: Andrey Ryabinin <a.ryabinin@samsung.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/20141219002956.GA25405@intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Andy Lutomirski 提交于
On x86_64, at least, task_pt_regs may be only partially initialized in many contexts, so x86_64 should not use it without extra care from interrupt context, let alone NMI context. This will allow x86_64 to override the logic and will supply some scratch space to use to make a cleaner copy of user regs. Tested-by: NJiri Olsa <jolsa@kernel.org> Signed-off-by: NAndy Lutomirski <luto@amacapital.net> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: chenggang.qcg@taobao.com Cc: Wu Fengguang <fengguang.wu@intel.com> Cc: Namhyung Kim <namhyung@gmail.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: David Ahern <dsahern@gmail.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Jean Pihet <jean.pihet@linaro.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mark Salter <msalter@redhat.com> Cc: Russell King <linux@arm.linux.org.uk> Cc: Will Deacon <will.deacon@arm.com> Cc: linux-arm-kernel@lists.infradead.org Link: http://lkml.kernel.org/r/e431cd4c18c2e1c44c774f10758527fb2d1025c4.1420396372.git.luto@amacapital.netSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Oleg Nesterov 提交于
wait_consider_task() checks EXIT_ZOMBIE after EXIT_DEAD/EXIT_TRACE and both checks can fail if we race with EXIT_ZOMBIE -> EXIT_DEAD/EXIT_TRACE change in between, gcc needs to reload p->exit_state after security_task_wait(). In this case ->notask_error will be wrongly cleared and do_wait() can hang forever if it was the last eligible child. Many thanks to Arne who carefully investigated the problem. Note: this bug is very old but it was pure theoretical until commit b3ab0316 ("wait: completely ignore the EXIT_DEAD tasks"). Before this commit "-O2" was probably enough to guarantee that compiler won't read ->exit_state twice. Signed-off-by: NOleg Nesterov <oleg@redhat.com> Reported-by: NArne Goedeke <el@laramies.com> Tested-by: NArne Goedeke <el@laramies.com> Cc: <stable@vger.kernel.org> [3.15+] Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 08 1月, 2015 2 次提交
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由 Sasha Levin 提交于
Verify that the frequency value from userspace is valid and makes sense. Unverified values can cause overflows later on. Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@kernel.org> Cc: stable <stable@vger.kernel.org> Signed-off-by: NSasha Levin <sasha.levin@oracle.com> [jstultz: Fix up bug for negative values and drop redunent cap check] Signed-off-by: NJohn Stultz <john.stultz@linaro.org>
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由 Sasha Levin 提交于
An unvalidated user input is multiplied by a constant, which can result in an undefined behaviour for large values. While this is validated later, we should avoid triggering undefined behaviour. Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@kernel.org> Cc: stable <stable@vger.kernel.org> Signed-off-by: NSasha Levin <sasha.levin@oracle.com> [jstultz: include trivial milisecond->microsecond correction noticed by Andy] Signed-off-by: NJohn Stultz <john.stultz@linaro.org>
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- 30 12月, 2014 1 次提交
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由 Paul Moore 提交于
Unfortunately, while commit 4a928436 ("audit: correctly record file names with different path name types") fixed a problem where we were not recording filenames, it created a new problem by attempting to use these file names after they had been freed. This patch resolves the issue by creating a copy of the filename which the audit subsystem frees after it is done with the string. At some point it would be nice to resolve this issue with refcounts, or something similar, instead of having to allocate/copy strings, but that is almost surely beyond the scope of a -rcX patch so we'll defer that for later. On the plus side, only audit users should be impacted by the string copying. Reported-by: NToralf Foerster <toralf.foerster@gmx.de> Signed-off-by: NPaul Moore <pmoore@redhat.com>
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- 27 12月, 2014 1 次提交
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由 Johannes Berg 提交于
Netlink families can exist in multiple namespaces, and for the most part multicast subscriptions are per network namespace. Thus it only makes sense to have bind/unbind notifications per network namespace. To achieve this, pass the network namespace of a given client socket to the bind/unbind functions. Also do this in generic netlink, and there also make sure that any bind for multicast groups that only exist in init_net is rejected. This isn't really a problem if it is accepted since a client in a different namespace will never receive any notifications from such a group, but it can confuse the family if not rejected (it's also possible to silently (without telling the family) accept it, but it would also have to be ignored on unbind so families that take any kind of action on bind/unbind won't do unnecessary work for invalid clients like that. Signed-off-by: NJohannes Berg <johannes.berg@intel.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 24 12月, 2014 1 次提交
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由 Richard Guy Briggs 提交于
A regression was caused by commit 780a7654: audit: Make testing for a valid loginuid explicit. (which in turn attempted to fix a regression caused by e1760bd5) When audit_krule_to_data() fills in the rules to get a listing, there was a missing clause to convert back from AUDIT_LOGINUID_SET to AUDIT_LOGINUID. This broke userspace by not returning the same information that was sent and expected. The rule: auditctl -a exit,never -F auid=-1 gives: auditctl -l LIST_RULES: exit,never f24=0 syscall=all when it should give: LIST_RULES: exit,never auid=-1 (0xffffffff) syscall=all Tag it so that it is reported the same way it was set. Create a new private flags audit_krule field (pflags) to store it that won't interact with the public one from the API. Cc: stable@vger.kernel.org # v3.10-rc1+ Signed-off-by: NRichard Guy Briggs <rgb@redhat.com> Signed-off-by: NPaul Moore <pmoore@redhat.com>
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- 23 12月, 2014 3 次提交
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由 Alex Thorlton 提交于
When allocating space for load_balance_mask, in sched_init, when CPUMASK_OFFSTACK is set, we've managed to spill over KMALLOC_MAX_SIZE on our 6144 core machine. The patch below breaks up the allocations so that they don't overflow the max alloc size. It also allocates the masks on the the node from which they'll most commonly be accessed, to minimize remote accesses on NUMA machines. Suggested-by: NGeorge Beshers <gbeshers@sgi.com> Signed-off-by: NAlex Thorlton <athorlton@sgi.com> Cc: George Beshers <gbeshers@sgi.com> Cc: Russ Anderson <rja@sgi.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/1418928270-148543-1-git-send-email-athorlton@sgi.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Rusty Russell 提交于
I rebased Kees' 'param: do not set store func without write perm' on top of my 'params: cleanup sysfs allocation'. However, my patch uses krealloc which doesn't zero memory, leaving .store unset. Reported-by: NSasha Levin <sasha.levin@oracle.com> Cc: Kees Cook <keescook@chromium.org> Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
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由 Paul Moore 提交于
There is a problem with the audit system when multiple audit records are created for the same path, each with a different path name type. The root cause of the problem is in __audit_inode() when an exact match (both the path name and path name type) is not found for a path name record; the existing code creates a new path name record, but it never sets the path name in this record, leaving it NULL. This patch corrects this problem by assigning the path name to these newly created records. There are many ways to reproduce this problem, but one of the easiest is the following (assuming auditd is running): # mkdir /root/tmp/test # touch /root/tmp/test/567 # auditctl -a always,exit -F dir=/root/tmp/test # touch /root/tmp/test/567 Afterwards, or while the commands above are running, check the audit log and pay special attention to the PATH records. A faulty kernel will display something like the following for the file creation: type=SYSCALL msg=audit(1416957442.025:93): arch=c000003e syscall=2 success=yes exit=3 ... comm="touch" exe="/usr/bin/touch" type=CWD msg=audit(1416957442.025:93): cwd="/root/tmp" type=PATH msg=audit(1416957442.025:93): item=0 name="test/" inode=401409 ... nametype=PARENT type=PATH msg=audit(1416957442.025:93): item=1 name=(null) inode=393804 ... nametype=NORMAL type=PATH msg=audit(1416957442.025:93): item=2 name=(null) inode=393804 ... nametype=NORMAL While a patched kernel will show the following: type=SYSCALL msg=audit(1416955786.566:89): arch=c000003e syscall=2 success=yes exit=3 ... comm="touch" exe="/usr/bin/touch" type=CWD msg=audit(1416955786.566:89): cwd="/root/tmp" type=PATH msg=audit(1416955786.566:89): item=0 name="test/" inode=401409 ... nametype=PARENT type=PATH msg=audit(1416955786.566:89): item=1 name="test/567" inode=393804 ... nametype=NORMAL This issue was brought up by a number of people, but special credit should go to hujianyang@huawei.com for reporting the problem along with an explanation of the problem and a patch. While the original patch did have some problems (see the archive link below), it did demonstrate the problem and helped kickstart the fix presented here. * https://lkml.org/lkml/2014/9/5/66Reported-by: Nhujianyang <hujianyang@huawei.com> Signed-off-by: NPaul Moore <pmoore@redhat.com> Acked-by: NRichard Guy Briggs <rgb@redhat.com>
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- 20 12月, 2014 3 次提交
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由 Richard Guy Briggs 提交于
Eric Paris explains: Since kauditd_send_multicast_skb() gets called in audit_log_end(), which can come from any context (aka even a sleeping context) GFP_KERNEL can't be used. Since the audit_buffer knows what context it should use, pass that down and use that. See: https://lkml.org/lkml/2014/12/16/542 BUG: sleeping function called from invalid context at mm/slab.c:2849 in_atomic(): 1, irqs_disabled(): 0, pid: 885, name: sulogin 2 locks held by sulogin/885: #0: (&sig->cred_guard_mutex){+.+.+.}, at: [<ffffffff91152e30>] prepare_bprm_creds+0x28/0x8b #1: (tty_files_lock){+.+.+.}, at: [<ffffffff9123e787>] selinux_bprm_committing_creds+0x55/0x22b CPU: 1 PID: 885 Comm: sulogin Not tainted 3.18.0-next-20141216 #30 Hardware name: Dell Inc. Latitude E6530/07Y85M, BIOS A15 06/20/2014 ffff880223744f10 ffff88022410f9b8 ffffffff916ba529 0000000000000375 ffff880223744f10 ffff88022410f9e8 ffffffff91063185 0000000000000006 0000000000000000 0000000000000000 0000000000000000 ffff88022410fa38 Call Trace: [<ffffffff916ba529>] dump_stack+0x50/0xa8 [<ffffffff91063185>] ___might_sleep+0x1b6/0x1be [<ffffffff910632a6>] __might_sleep+0x119/0x128 [<ffffffff91140720>] cache_alloc_debugcheck_before.isra.45+0x1d/0x1f [<ffffffff91141d81>] kmem_cache_alloc+0x43/0x1c9 [<ffffffff914e148d>] __alloc_skb+0x42/0x1a3 [<ffffffff914e2b62>] skb_copy+0x3e/0xa3 [<ffffffff910c263e>] audit_log_end+0x83/0x100 [<ffffffff9123b8d3>] ? avc_audit_pre_callback+0x103/0x103 [<ffffffff91252a73>] common_lsm_audit+0x441/0x450 [<ffffffff9123c163>] slow_avc_audit+0x63/0x67 [<ffffffff9123c42c>] avc_has_perm+0xca/0xe3 [<ffffffff9123dc2d>] inode_has_perm+0x5a/0x65 [<ffffffff9123e7ca>] selinux_bprm_committing_creds+0x98/0x22b [<ffffffff91239e64>] security_bprm_committing_creds+0xe/0x10 [<ffffffff911515e6>] install_exec_creds+0xe/0x79 [<ffffffff911974cf>] load_elf_binary+0xe36/0x10d7 [<ffffffff9115198e>] search_binary_handler+0x81/0x18c [<ffffffff91153376>] do_execveat_common.isra.31+0x4e3/0x7b7 [<ffffffff91153669>] do_execve+0x1f/0x21 [<ffffffff91153967>] SyS_execve+0x25/0x29 [<ffffffff916c61a9>] stub_execve+0x69/0xa0 Cc: stable@vger.kernel.org #v3.16-rc1 Reported-by: NValdis Kletnieks <Valdis.Kletnieks@vt.edu> Signed-off-by: NRichard Guy Briggs <rgb@redhat.com> Tested-by: NValdis Kletnieks <Valdis.Kletnieks@vt.edu> Signed-off-by: NPaul Moore <pmoore@redhat.com>
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由 Paul Moore 提交于
Commit f1dc4867 ("audit: anchor all pid references in the initial pid namespace") introduced a find_vpid() call when adding/removing audit rules with PID/PPID filters; unfortunately this is problematic as find_vpid() only works if there is a task with the associated PID alive on the system. The following commands demonstrate a simple reproducer. # auditctl -D # auditctl -l # autrace /bin/true # auditctl -l This patch resolves the problem by simply using the PID provided by the user without any additional validation, e.g. no calls to check to see if the task/PID exists. Cc: stable@vger.kernel.org # 3.15 Cc: Richard Guy Briggs <rgb@redhat.com> Signed-off-by: NPaul Moore <pmoore@redhat.com> Acked-by: NEric Paris <eparis@redhat.com> Reviewed-by: NRichard Guy Briggs <rgb@redhat.com>
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由 Rafael J. Wysocki 提交于
Having switched over all of the users of CONFIG_PM_RUNTIME to use CONFIG_PM directly, turn the latter into a user-selectable option and drop the former entirely from the tree. Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: NUlf Hansson <ulf.hansson@linaro.org> Acked-by: NKevin Hilman <khilman@linaro.org>
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- 19 12月, 2014 1 次提交
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由 Thomas Gleixner 提交于
commit 4dbd2771 "tick: export nohz tick idle symbols for module use" was merged via the thermal tree without an explicit ack from the relevant maintainers. The exports are abused by the intel powerclamp driver which implements a fake idle state from a sched FIFO task. This causes all kinds of wreckage in the NOHZ core code which rightfully assumes that tick_nohz_idle_enter/exit() are only called from the idle task itself. Recent changes in the NOHZ core lead to a failure of the powerclamp driver and now people try to hack completely broken and backwards workarounds into the NOHZ core code. This is completely unacceptable and just papers over the real problem. There are way more subtle issues lurking around the corner. The real solution is to fix the powerclamp driver by rewriting it with a sane concept, but that's beyond the scope of this. So the only solution for now is to remove the calls into the core NOHZ code from the powerclamp trainwreck along with the exports. Fixes: d6d71ee4 "PM: Introduce Intel PowerClamp Driver" Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com> Cc: Viresh Kumar <viresh.kumar@linaro.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Fengguang Wu <fengguang.wu@intel.com> Cc: Frederic Weisbecker <frederic@kernel.org> Cc: Pan Jacob jun <jacob.jun.pan@intel.com> Cc: LKP <lkp@01.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Zhang Rui <rui.zhang@intel.com> Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1412181110110.17382@nanosSigned-off-by: NThomas Gleixner <tglx@linutronix.de>
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- 18 12月, 2014 1 次提交
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由 Kees Cook 提交于
When a module_param is defined without DAC write permissions, it can still be changed at runtime and updated. Drivers using a 0444 permission may be surprised that these values can still be changed. For drivers that want to allow updates, any S_IW* flag will set the "store" function as before. Drivers without S_IW* flags will have the "store" function unset, unforcing a read-only value. Drivers that wish neither "store" nor "get" can continue to use "0" for perms to stay out of sysfs entirely. Old behavior: # cd /sys/module/snd/parameters # ls -l total 0 -r--r--r-- 1 root root 4096 Dec 11 13:55 cards_limit -r--r--r-- 1 root root 4096 Dec 11 13:55 major -r--r--r-- 1 root root 4096 Dec 11 13:55 slots # cat major 116 # echo -1 > major -bash: major: Permission denied # chmod u+w major # echo -1 > major # cat major -1 New behavior: ... # chmod u+w major # echo -1 > major -bash: echo: write error: Input/output error Signed-off-by: NKees Cook <keescook@chromium.org> Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
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- 15 12月, 2014 1 次提交
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由 Steven Rostedt (Red Hat) 提交于
Add the kernel command line tp_printk option that will have tracepoints that are active sent to printk() as well as to the trace buffer. Passing "tp_printk" will activate this. To turn it off, the sysctl /proc/sys/kernel/tracepoint_printk can have '0' echoed into it. Note, this only works if the cmdline option is used. Echoing 1 into the sysctl file without the cmdline option will have no affect. Note, this is a dangerous option. Having high frequency tracepoints send their data to printk() can possibly cause a live lock. This is another reason why this is only active if the command line option is used. Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1412121539300.16494@nanosSuggested-by: NThomas Gleixner <tglx@linutronix.de> Tested-by: NThomas Gleixner <tglx@linutronix.de> Acked-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
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