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2016-01-09Merge branch 'sched-urgent-for-linus' of ↵Linus Torvalds2-1/+2
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler fixes from Ingo Molnar: "Misc scheduler fixes" * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/core: Reset task's lockless wake-queues on fork() sched/core: Fix unserialized r-m-w scribbling stuff sched/core: Check tgid in is_global_init() sched/fair: Fix multiplication overflow on 32-bit systems
2016-01-09Merge branch 'perf-urgent-for-linus' of ↵Linus Torvalds1-29/+6
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf fixes from Ingo Molnar: "Two core subsystem fixes, plus a handful of tooling fixes" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf: Fix race in swevent hash perf: Fix race in perf_event_exec() perf list: Robustify event printing routine perf list: Add support for PERF_COUNT_SW_BPF_OUT perf hists browser: Fix segfault if use symbol filter in cmdline perf hists browser: Reset selection when refresh perf hists browser: Add NULL pointer check to prevent crash perf buildid-list: Fix return value of perf buildid-list -k perf buildid-list: Show running kernel build id fix
2016-01-09Merge branch 'irq-urgent-for-linus' of ↵Linus Torvalds1-3/+3
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull irq fix from Ingo Molnar: "Fixes a core IRQ subsystem deadlock" * 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: genirq: Prevent chip buslock deadlock
2016-01-07Merge tag 'trace-v4.4-rc4-4' of ↵Linus Torvalds1-0/+6
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull ftrace fix from Steven Rostedt: "PeiyangX Qiu reported that if a module fails to load between calling ftrace_module_init() and do_init_module() that the allocations made in ftrace_module_init() will not be freed, resulting in a memory leak. The solution is to call ftrace_release_mod() on the failing module in the fail path befor do_init_module() is called. This will remove any allocations made for that module, and nothing if ftrace_module_init() wasn't called yet for that module. Note, once do_init_module() is called, the MODULE_GOING notifiers are called for the failed module, which calls into the ftrace code to do the proper clean up (basically calling ftrace_release_mod())" * tag 'trace-v4.4-rc4-4' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: ftrace/module: Call clean up function when module init fails early
2016-01-07ftrace/module: Call clean up function when module init fails earlySteven Rostedt (Red Hat)1-0/+6
If the module init code fails after calling ftrace_module_init() and before calling do_init_module(), we can suffer from a memory leak. This is because ftrace_module_init() allocates pages to store the locations that ftrace hooks are placed in the module text. If do_init_module() fails, it still calls the MODULE_GOING notifiers which will tell ftrace to do a clean up of the pages it allocated for the module. But if load_module() fails before then, the pages allocated by ftrace_module_init() will never be freed. Call ftrace_release_mod() on the module if load_module() fails before getting to do_init_module(). Link: http://lkml.kernel.org/r/567CEA31.1070507@intel.com Reported-by: "Qiu, PeiyangX" <peiyangx.qiu@intel.com> Fixes: a949ae560a511 "ftrace/module: Hardcode ftrace_module_init() call into load_module()" Cc: stable@vger.kernel.org # v2.6.38+ Acked-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-01-06sched/core: Reset task's lockless wake-queues on fork()Sebastian Andrzej Siewior1-0/+1
In the following commit: 7675104990ed ("sched: Implement lockless wake-queues") we gained lockless wake-queues. The -RT kernel managed to lockup itself with those. There could be multiple attempts for task X to enqueue it for a wakeup _even_ if task X is already running. The reason is that task X could be runnable but not yet on CPU. The the task performing the wakeup did not leave the CPU it could performe multiple wakeups. With the proper timming task X could be running and enqueued for a wakeup. If this happens while X is performing a fork() then its its child will have a !NULL `wake_q` member copied. This is not a problem as long as the child task does not participate in lockless wakeups :) Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Davidlohr Bueso <dbueso@suse.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: 7675104990ed ("sched: Implement lockless wake-queues") Link: http://lkml.kernel.org/r/20151221171710.GA5499@linutronix.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-01-06sched/fair: Fix multiplication overflow on 32-bit systemsAndrey Ryabinin1-1/+1
Make 'r' 64-bit type to avoid overflow in 'r * LOAD_AVG_MAX' on 32-bit systems: UBSAN: Undefined behaviour in kernel/sched/fair.c:2785:18 signed integer overflow: 87950 * 47742 cannot be represented in type 'int' The most likely effect of this bug are bad load average numbers resulting in weird scheduling. It's also likely that this can persist for a longer time - until the system goes idle for a long time so that all load avg numbers get reset. [ This is the CFS load average metric, not the procfs output, which is separate. ] Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: 9d89c257dfb9 ("sched/fair: Rewrite runnable load and utilization average tracking") Link: http://lkml.kernel.org/r/1450097243-30137-1-git-send-email-aryabinin@virtuozzo.com [ Improved the changelog. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-01-06perf: Fix race in swevent hashPeter Zijlstra1-19/+1
There's a race on CPU unplug where we free the swevent hash array while it can still have events on. This will result in a use-after-free which is BAD. Simply do not free the hash array on unplug. This leaves the thing around and no use-after-free takes place. When the last swevent dies, we do a for_each_possible_cpu() iteration anyway to clean these up, at which time we'll free it, so no leakage will occur. Reported-by: Sasha Levin <sasha.levin@oracle.com> Tested-by: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-01-06perf: Fix race in perf_event_exec()Peter Zijlstra1-10/+5
I managed to tickle this warning: [ 2338.884942] ------------[ cut here ]------------ [ 2338.890112] WARNING: CPU: 13 PID: 35162 at ../kernel/events/core.c:2702 task_ctx_sched_out+0x6b/0x80() [ 2338.900504] Modules linked in: [ 2338.903933] CPU: 13 PID: 35162 Comm: bash Not tainted 4.4.0-rc4-dirty #244 [ 2338.911610] Hardware name: Intel Corporation S2600GZ/S2600GZ, BIOS SE5C600.86B.02.02.0002.122320131210 12/23/2013 [ 2338.923071] ffffffff81f1468e ffff8807c6457cb8 ffffffff815c680c 0000000000000000 [ 2338.931382] ffff8807c6457cf0 ffffffff810c8a56 ffffe8ffff8c1bd0 ffff8808132ed400 [ 2338.939678] 0000000000000286 ffff880813170380 ffff8808132ed400 ffff8807c6457d00 [ 2338.947987] Call Trace: [ 2338.950726] [<ffffffff815c680c>] dump_stack+0x4e/0x82 [ 2338.956474] [<ffffffff810c8a56>] warn_slowpath_common+0x86/0xc0 [ 2338.963195] [<ffffffff810c8b4a>] warn_slowpath_null+0x1a/0x20 [ 2338.969720] [<ffffffff811a49cb>] task_ctx_sched_out+0x6b/0x80 [ 2338.976244] [<ffffffff811a62d2>] perf_event_exec+0xe2/0x180 [ 2338.982575] [<ffffffff8121fb6f>] setup_new_exec+0x6f/0x1b0 [ 2338.988810] [<ffffffff8126de83>] load_elf_binary+0x393/0x1660 [ 2338.995339] [<ffffffff811dc772>] ? get_user_pages+0x52/0x60 [ 2339.001669] [<ffffffff8121e297>] search_binary_handler+0x97/0x200 [ 2339.008581] [<ffffffff8121f8b3>] do_execveat_common.isra.33+0x543/0x6e0 [ 2339.016072] [<ffffffff8121fcea>] SyS_execve+0x3a/0x50 [ 2339.021819] [<ffffffff819fc165>] stub_execve+0x5/0x5 [ 2339.027469] [<ffffffff819fbeb2>] ? entry_SYSCALL_64_fastpath+0x12/0x71 [ 2339.034860] ---[ end trace ee1337c59a0ddeac ]--- Which is a WARN_ON_ONCE() indicating that cpuctx->task_ctx is not what we expected it to be. This is because context switches can swap the task_struct::perf_event_ctxp[] pointer around. Therefore you have to either disable preemption when looking at current, or hold ctx->lock. Fix perf_event_enable_on_exec(), it loads current->perf_event_ctxp[] before disabling interrupts, therefore a preemption in the right place can swap contexts around and we're using the wrong one. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Potapenko <glider@google.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Eric Dumazet <edumazet@google.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Kostya Serebryany <kcc@google.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sasha Levin <sasha.levin@oracle.com> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: syzkaller <syzkaller@googlegroups.com> Link: http://lkml.kernel.org/r/20151210195740.GG6357@twins.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-01-06Merge tag 'trace-v4.4-rc4-3' of ↵Linus Torvalds1-0/+1
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing fixes from Steven Rostedt: "Two more fixes: 1. The recordmcount change had an output that used sprintf() (incorrectly) when it should have been a fprintf() to stderr. 2. The printk_formats file could crash if someone added a trace_printk() in the core kernel, and also added one in a module. This does not affect production kernels. Only kernels where developers add trace_printk() for debugging can crash" * tag 'trace-v4.4-rc4-3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: tracing: Fix setting of start_index in find_next() ftrace/scripts: Fix incorrect use of sprintf in recordmcount
2016-01-04tracing: Fix setting of start_index in find_next()Qiu Peiyang1-0/+1
When we do cat /sys/kernel/debug/tracing/printk_formats, we hit kernel panic at t_show. general protection fault: 0000 [#1] PREEMPT SMP CPU: 0 PID: 2957 Comm: sh Tainted: G W O 3.14.55-x86_64-01062-gd4acdc7 #2 RIP: 0010:[<ffffffff811375b2>] [<ffffffff811375b2>] t_show+0x22/0xe0 RSP: 0000:ffff88002b4ebe80 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000004 RDX: 0000000000000004 RSI: ffffffff81fd26a6 RDI: ffff880032f9f7b1 RBP: ffff88002b4ebe98 R08: 0000000000001000 R09: 000000000000ffec R10: 0000000000000000 R11: 000000000000000f R12: ffff880004d9b6c0 R13: 7365725f6d706400 R14: ffff880004d9b6c0 R15: ffffffff82020570 FS: 0000000000000000(0000) GS:ffff88003aa00000(0063) knlGS:00000000f776bc40 CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 CR2: 00000000f6c02ff0 CR3: 000000002c2b3000 CR4: 00000000001007f0 Call Trace: [<ffffffff811dc076>] seq_read+0x2f6/0x3e0 [<ffffffff811b749b>] vfs_read+0x9b/0x160 [<ffffffff811b7f69>] SyS_read+0x49/0xb0 [<ffffffff81a3a4b9>] ia32_do_call+0x13/0x13 ---[ end trace 5bd9eb630614861e ]--- Kernel panic - not syncing: Fatal exception When the first time find_next calls find_next_mod_format, it should iterate the trace_bprintk_fmt_list to find the first print format of the module. However in current code, start_index is smaller than *pos at first, and code will not iterate the list. Latter container_of will get the wrong address with former v, which will cause mod_fmt be a meaningless object and so is the returned mod_fmt->fmt. This patch will fix it by correcting the start_index. After fixed, when the first time calls find_next_mod_format, start_index will be equal to *pos, and code will iterate the trace_bprintk_fmt_list to get the right module printk format, so is the returned mod_fmt->fmt. Link: http://lkml.kernel.org/r/5684B900.9000309@intel.com Cc: stable@vger.kernel.org # 3.12+ Fixes: 102c9323c35a8 "tracing: Add __tracepoint_string() to export string pointers" Signed-off-by: Qiu Peiyang <peiyangx.qiu@intel.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-12-17locking/osq: Fix ordering of node initialisation in osq_lockWill Deacon1-3/+5
The Cavium guys reported a soft lockup on their arm64 machine, caused by commit c55a6ffa6285 ("locking/osq: Relax atomic semantics"): mutex_optimistic_spin+0x9c/0x1d0 __mutex_lock_slowpath+0x44/0x158 mutex_lock+0x54/0x58 kernfs_iop_permission+0x38/0x70 __inode_permission+0x88/0xd8 inode_permission+0x30/0x6c link_path_walk+0x68/0x4d4 path_openat+0xb4/0x2bc do_filp_open+0x74/0xd0 do_sys_open+0x14c/0x228 SyS_openat+0x3c/0x48 el0_svc_naked+0x24/0x28 This is because in osq_lock we initialise the node for the current CPU: node->locked = 0; node->next = NULL; node->cpu = curr; and then publish the current CPU in the lock tail: old = atomic_xchg_acquire(&lock->tail, curr); Once the update to lock->tail is visible to another CPU, the node is then live and can be both read and updated by concurrent lockers. Unfortunately, the ACQUIRE semantics of the xchg operation mean that there is no guarantee the contents of the node will be visible before lock tail is updated. This can lead to lock corruption when, for example, a concurrent locker races to set the next field. Fixes: c55a6ffa6285 ("locking/osq: Relax atomic semantics"): Reported-by: David Daney <ddaney@caviumnetworks.com> Reported-by: Andrew Pinski <andrew.pinski@caviumnetworks.com> Tested-by: Andrew Pinski <andrew.pinski@caviumnetworks.com> Acked-by: Davidlohr Bueso <dave@stgolabs.net> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: http://lkml.kernel.org/r/1449856001-21177-1-git-send-email-will.deacon@arm.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-12-14genirq: Prevent chip buslock deadlockThomas Gleixner1-3/+3
If a interrupt chip utilizes chip->buslock then free_irq() can deadlock in the following way: CPU0 CPU1 interrupt(X) (Shared or spurious) free_irq(X) interrupt_thread(X) chip_bus_lock(X) irq_finalize_oneshot(X) chip_bus_lock(X) synchronize_irq(X) synchronize_irq() waits for the interrupt thread to complete, i.e. forever. Solution is simple: Drop chip_bus_lock() before calling synchronize_irq() as we do with the irq_desc lock. There is nothing to be protected after the point where irq_desc lock has been released. This adds chip_bus_lock/unlock() to the remove_irq() code path, but that's actually correct in the case where remove_irq() is called on such an interrupt. The current users of remove_irq() are not affected as none of those interrupts is on a chip which requires buslock. Reported-by: Fredrik Markström <fredrik.markstrom@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org
2015-12-14sched/wait: Fix the signal handling fixPeter Zijlstra1-10/+10
Jan Stancek reported that I wrecked things for him by fixing things for Vladimir :/ His report was due to an UNINTERRUPTIBLE wait getting -EINTR, which should not be possible, however my previous patch made this possible by unconditionally checking signal_pending(). We cannot use current->state as was done previously, because the instruction after the store to that variable it can be changed. We must instead pass the initial state along and use that. Fixes: 68985633bccb ("sched/wait: Fix signal handling in bit wait helpers") Reported-by: Jan Stancek <jstancek@redhat.com> Reported-by: Chris Mason <clm@fb.com> Tested-by: Jan Stancek <jstancek@redhat.com> Tested-by: Vladimir Murzin <vladimir.murzin@arm.com> Tested-by: Chris Mason <clm@fb.com> Reviewed-by: Paul Turner <pjt@google.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: tglx@linutronix.de Cc: Oleg Nesterov <oleg@redhat.com> Cc: hpa@zytor.com Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-12-12kernel: remove stop_machine() Kconfig dependencyChris Wilson1-2/+2
Currently the full stop_machine() routine is only enabled on SMP if module unloading is enabled, or if the CPUs are hotpluggable. This leads to configurations where stop_machine() is broken as it will then only run the callback on the local CPU with irqs disabled, and not stop the other CPUs or run the callback on them. For example, this breaks MTRR setup on x86 in certain configs since ea8596bb2d8d379 ("kprobes/x86: Remove unused text_poke_smp() and text_poke_smp_batch() functions") as the MTRR is only established on the boot CPU. This patch removes the Kconfig option for STOP_MACHINE and uses the SMP and HOTPLUG_CPU config options to compile the correct stop_machine() for the architecture, removing the false dependency on MODULE_UNLOAD in the process. Link: https://lkml.org/lkml/2014/10/8/124 References: https://bugs.freedesktop.org/show_bug.cgi?id=84794 Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Acked-by: Ingo Molnar <mingo@kernel.org> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: Pranith Kumar <bobby.prani@gmail.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: Vladimir Davydov <vdavydov@parallels.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: H. Peter Anvin <hpa@linux.intel.com> Cc: Tejun Heo <tj@kernel.org> Cc: Iulia Manda <iulia.manda21@gmail.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Chuck Ebbert <cebbert.lkml@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-12-09Merge branch 'for-4.4-fixes' of ↵Linus Torvalds7-118/+141
git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup Pull cgroup fixes from Tejun Heo: "More change than I'd have liked at this stage. The pids controller and the changes made to cgroup core to support it introduced and revealed several important issues. - Assigning membership to a newly created task and migrating it can race leading to incorrect accounting. Oleg fixed it by widening threadgroup synchronization. It looks like we'll be able to merge it with a different percpu rwsem which is used in fork path making things simpler and cheaper. - The recent change to extend cgroup membership to zombies (so that pid accounting can extend till the pid is actually released) missed pinning the underlying data structures leading to use-after-free. Fixed. - v2 hierarchy was calling subsystem callbacks with the wrong target cgroup_subsys_state based on the incorrect assumption that they share the same target. pids is the first controller affected by this. Subsys callbacks updated so that they can deal with multi-target migrations" * 'for-4.4-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: cgroup_pids: don't account for the root cgroup cgroup: fix handling of multi-destination migration from subtree_control enabling cgroup_freezer: simplify propagation of CGROUP_FROZEN clearing in freezer_attach() cgroup: pids: kill pids_fork(), simplify pids_can_fork() and pids_cancel_fork() cgroup: pids: fix race between cgroup_post_fork() and cgroup_migrate() cgroup: make css_set pin its css's to avoid use-afer-free cgroup: fix cftype->file_offset handling
2015-12-09Merge branch 'perf-urgent-for-linus' of ↵Linus Torvalds11-33/+71
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf fixes from Ingo Molnar: "This tree includes four core perf fixes for misc bugs, three fixes to x86 PMU drivers, and two updates to old email addresses" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf: Do not send exit event twice perf/x86/intel: Fix INTEL_FLAGS_UEVENT_CONSTRAINT_DATALA_NA macro perf/x86/intel: Make L1D_PEND_MISS.FB_FULL not constrained on Haswell perf: Fix PERF_EVENT_IOC_PERIOD deadlock treewide: Remove old email address perf/x86: Fix LBR call stack save/restore perf: Update email address in MAINTAINERS perf/core: Robustify the perf_cgroup_from_task() RCU checks perf/core: Fix RCU problem with cgroup context switching code
2015-12-07Merge branch 'master' into for-4.4-fixesTejun Heo16-56/+147
The following commit which went into mainline through networking tree 3b13758f51de ("cgroups: Allow dynamically changing net_classid") conflicts in net/core/netclassid_cgroup.c with the following pending fix in cgroup/for-4.4-fixes. 1f7dd3e5a6e4 ("cgroup: fix handling of multi-destination migration from subtree_control enabling") The former separates out update_classid() from cgrp_attach() and updates it to walk all fds of all tasks in the target css so that it can be used from both migration and config change paths. The latter drops @css from cgrp_attach(). Resolve the conflict by making cgrp_attach() call update_classid() with the css from the first task. We can revive @tset walking in cgrp_attach() but given that net_cls is v1 only where there always is only one target css during migration, this is fine. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Nina Schiff <ninasc@fb.com>
2015-12-06Merge branch 'sched-urgent-for-linus' of ↵Linus Torvalds5-15/+45
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler fixes from Thomas Gleixner: "This updates contains the following changes: - Fix a signal handling regression in the bit wait functions. - Avoid false positive warnings in the wakeup path. - Initialize the scheduler root domain properly. - Handle gtime calculations in proc/$PID/stat proper. - Add more documentation for the barriers in try_to_wake_up(). - Fix a subtle race in try_to_wake_up() which might cause a task to be scheduled on two cpus - Compile static helper function only when it is used" * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/core: Fix an SMP ordering race in try_to_wake_up() vs. schedule() sched/core: Better document the try_to_wake_up() barriers sched/cputime: Fix invalid gtime in proc sched/core: Clear the root_domain cpumasks in init_rootdomain() sched/core: Remove false-positive warning from wake_up_process() sched/wait: Fix signal handling in bit wait helpers sched/rt: Hide the push_irq_work_func() declaration
2015-12-06perf: Do not send exit event twiceJiri Olsa1-11/+31
In case we monitor events system wide, we get EXIT event (when configured) twice for each task that exited. Note doubled lines with same pid/tid in following example: $ sudo ./perf record -a ^C[ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 0.480 MB perf.data (2518 samples) ] $ sudo ./perf report -D | grep EXIT 0 60290687567581 0x59910 [0x38]: PERF_RECORD_EXIT(1250:1250):(1250:1250) 0 60290687568354 0x59948 [0x38]: PERF_RECORD_EXIT(1250:1250):(1250:1250) 0 60290687988744 0x59ad8 [0x38]: PERF_RECORD_EXIT(1250:1250):(1250:1250) 0 60290687989198 0x59b10 [0x38]: PERF_RECORD_EXIT(1250:1250):(1250:1250) 1 60290692567895 0x62af0 [0x38]: PERF_RECORD_EXIT(1253:1253):(1253:1253) 1 60290692568322 0x62b28 [0x38]: PERF_RECORD_EXIT(1253:1253):(1253:1253) 2 60290692739276 0x69a18 [0x38]: PERF_RECORD_EXIT(1252:1252):(1252:1252) 2 60290692739910 0x69a50 [0x38]: PERF_RECORD_EXIT(1252:1252):(1252:1252) The reason is that the cpu contexts are processes each time we call perf_event_task. I'm changing the perf_event_aux logic to serve task_ctx and cpu contexts separately, which ensure we don't get EXIT event generated twice on same cpu context. This does not affect other auxiliary events, as they don't use task_ctx at all. Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: David Ahern <dsahern@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Link: http://lkml.kernel.org/r/1446649205-5822-1-git-send-email-jolsa@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-12-04sched/core: Fix an SMP ordering race in try_to_wake_up() vs. schedule()Peter Zijlstra1-0/+19
Oleg noticed that its possible to falsely observe p->on_cpu == 0 such that we'll prematurely continue with the wakeup and effectively run p on two CPUs at the same time. Even though the overlap is very limited; the task is in the middle of being scheduled out; it could still result in corruption of the scheduler data structures. CPU0 CPU1 set_current_state(...) <preempt_schedule> context_switch(X, Y) prepare_lock_switch(Y) Y->on_cpu = 1; finish_lock_switch(X) store_release(X->on_cpu, 0); try_to_wake_up(X) LOCK(p->pi_lock); t = X->on_cpu; // 0 context_switch(Y, X) prepare_lock_switch(X) X->on_cpu = 1; finish_lock_switch(Y) store_release(Y->on_cpu, 0); </preempt_schedule> schedule(); deactivate_task(X); X->on_rq = 0; if (X->on_rq) // false if (t) while (X->on_cpu) cpu_relax(); context_switch(X, ..) finish_lock_switch(X) store_release(X->on_cpu, 0); Avoid the load of X->on_cpu being hoisted over the X->on_rq load. Reported-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-12-04sched/core: Better document the try_to_wake_up() barriersPeter Zijlstra2-1/+10
Explain how the control dependency and smp_rmb() end up providing ACQUIRE semantics and pair with smp_store_release() in finish_lock_switch(). Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-12-04sched/cputime: Fix invalid gtime in procHiroshi Shimamoto1-0/+3
/proc/stats shows invalid gtime when the thread is running in guest. When vtime accounting is not enabled, we cannot get a valid delta. The delta is calculated with now - tsk->vtime_snap, but tsk->vtime_snap is only updated when vtime accounting is runtime enabled. This patch makes task_gtime() just return gtime without computing the buggy non-existing tickless delta when vtime accounting is not enabled. Use context_tracking_is_enabled() to check if vtime is accounting on some cpu, in which case only we need to check the tickless delta. This way we fix the gtime value regression on machines not running nohz full. The kernel config contains CONFIG_VIRT_CPU_ACCOUNTING_GEN=y and CONFIG_NO_HZ_FULL_ALL=n and boot without nohz_full. I ran and stop a busy loop in VM and see the gtime in host. Dump the 43rd field which shows the gtime in every second: # while :; do awk '{print $3" "$43}' /proc/3955/task/4014/stat; sleep 1; done S 4348 R 7064566 R 7064766 R 7064967 R 7065168 S 4759 S 4759 During running busy loop, it returns large value. After applying this patch, we can see right gtime. # while :; do awk '{print $3" "$43}' /proc/10913/task/10956/stat; sleep 1; done S 5338 R 5365 R 5465 R 5566 R 5666 S 5726 S 5726 Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Chris Metcalf <cmetcalf@ezchip.com> Cc: Christoph Lameter <cl@linux.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Luiz Capitulino <lcapitulino@redhat.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul E . McKenney <paulmck@linux.vnet.ibm.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1447948054-28668-2-git-send-email-fweisbec@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-12-04sched/core: Clear the root_domain cpumasks in init_rootdomain()Xunlei Pang1-4/+4
root_domain::rto_mask allocated through alloc_cpumask_var() contains garbage data, this may cause problems. For instance, When doing pull_rt_task(), it may do useless iterations if rto_mask retains some extra garbage bits. Worse still, this violates the isolated domain rule for clustered scheduling using cpuset, because the tasks(with all the cpus allowed) belongs to one root domain can be pulled away into another root domain. The patch cleans the garbage by using zalloc_cpumask_var() instead of alloc_cpumask_var() for root_domain::rto_mask allocation, thereby addressing the issues. Do the same thing for root_domain's other cpumask memembers: dlo_mask, span, and online. Signed-off-by: Xunlei Pang <xlpang@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: <stable@vger.kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1449057179-29321-1-git-send-email-xlpang@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-12-04sched/core: Remove false-positive warning from wake_up_process()Sasha Levin1-1/+0
Because wakeups can (fundamentally) be late, a task might not be in the expected state. Therefore testing against a task's state is racy, and can yield false positives. Signed-off-by: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: oleg@redhat.com Fixes: 9067ac85d533 ("wake_up_process() should be never used to wakeup a TASK_STOPPED/TRACED task") Link: http://lkml.kernel.org/r/1448933660-23082-1-git-send-email-sasha.levin@oracle.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-12-04sched/wait: Fix signal handling in bit wait helpersPeter Zijlstra1-8/+8
Vladimir reported getting RCU stall warnings and bisected it back to commit: 743162013d40 ("sched: Remove proliferation of wait_on_bit() action functions") That commit inadvertently reversed the calls to schedule() and signal_pending(), thereby not handling the case where the signal receives while we sleep. Reported-by: Vladimir Murzin <vladimir.murzin@arm.com> Tested-by: Vladimir Murzin <vladimir.murzin@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: mark.rutland@arm.com Cc: neilb@suse.de Cc: oleg@redhat.com Fixes: 743162013d40 ("sched: Remove proliferation of wait_on_bit() action functions") Fixes: cbbce8220949 ("SCHED: add some "wait..on_bit...timeout()" interfaces.") Link: http://lkml.kernel.org/r/20151201130404.GL3816@twins.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-12-04perf: Fix PERF_EVENT_IOC_PERIOD deadlockPeter Zijlstra1-1/+8
Dmitry reported a fairly silly recursive lock deadlock for PERF_EVENT_IOC_PERIOD, fix this by explicitly doing the inactive part of __perf_event_period() instead of calling that function. Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: <stable@vger.kernel.org> Cc: Alexander Potapenko <glider@google.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Eric Dumazet <edumazet@google.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Kostya Serebryany <kcc@google.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sasha Levin <sasha.levin@oracle.com> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Fixes: c7999c6f3fed ("perf: Fix PERF_EVENT_IOC_PERIOD migration race") Link: http://lkml.kernel.org/r/20151130115615.GJ17308@twins.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-12-04Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netLinus Torvalds5-29/+64
Pull networking fixes from David Miller: "A lot of Thanksgiving turkey leftovers accumulated, here goes: 1) Fix bluetooth l2cap_chan object leak, from Johan Hedberg. 2) IDs for some new iwlwifi chips, from Oren Givon. 3) Fix rtlwifi lockups on boot, from Larry Finger. 4) Fix memory leak in fm10k, from Stephen Hemminger. 5) We have a route leak in the ipv6 tunnel infrastructure, fix from Paolo Abeni. 6) Fix buffer pointer handling in arm64 bpf JIT,f rom Zi Shen Lim. 7) Wrong lockdep annotations in tcp md5 support, fix from Eric Dumazet. 8) Work around some middle boxes which prevent proper handling of TCP Fast Open, from Yuchung Cheng. 9) TCP repair can do huge kmalloc() requests, build paged SKBs instead. From Eric Dumazet. 10) Fix msg_controllen overflow in scm_detach_fds, from Daniel Borkmann. 11) Fix device leaks on ipmr table destruction in ipv4 and ipv6, from Nikolay Aleksandrov. 12) Fix use after free in epoll with AF_UNIX sockets, from Rainer Weikusat. 13) Fix double free in VRF code, from Nikolay Aleksandrov. 14) Fix skb leaks on socket receive queue in tipc, from Ying Xue. 15) Fix ifup/ifdown crach in xgene driver, from Iyappan Subramanian. 16) Fix clearing of persistent array maps in bpf, from Daniel Borkmann. 17) In TCP, for the cross-SYN case, we don't initialize tp->copied_seq early enough. From Eric Dumazet. 18) Fix out of bounds accesses in bpf array implementation when updating elements, from Daniel Borkmann. 19) Fill gaps in RCU protection of np->opt in ipv6 stack, from Eric Dumazet. 20) When dumping proxy neigh entries, we have to accomodate NULL device pointers properly, from Konstantin Khlebnikov. 21) SCTP doesn't release all ipv6 socket resources properly, fix from Eric Dumazet. 22) Prevent underflows of sch->q.qlen for multiqueue packet schedulers, also from Eric Dumazet. 23) Fix MAC and unicast list handling in bnxt_en driver, from Jeffrey Huang and Michael Chan. 24) Don't actively scan radar channels, from Antonio Quartulli" * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (110 commits) net: phy: reset only targeted phy bnxt_en: Setup uc_list mac filters after resetting the chip. bnxt_en: enforce proper storing of MAC address bnxt_en: Fixed incorrect implementation of ndo_set_mac_address net: lpc_eth: remove irq > NR_IRQS check from probe() net_sched: fix qdisc_tree_decrease_qlen() races openvswitch: fix hangup on vxlan/gre/geneve device deletion ipv4: igmp: Allow removing groups from a removed interface ipv6: sctp: implement sctp_v6_destroy_sock() arm64: bpf: add 'store immediate' instruction ipv6: kill sk_dst_lock ipv6: sctp: add rcu protection around np->opt net/neighbour: fix crash at dumping device-agnostic proxy entries sctp: use GFP_USER for user-controlled kmalloc sctp: convert sack_needed and sack_generation to bits ipv6: add complete rcu protection around np->opt bpf: fix allocation warnings in bpf maps and integer overflow mvebu: dts: enable IP checksum with jumbo frames for Armada 38x on Port0 net: mvneta: enable setting custom TX IP checksum limit net: mvneta: fix error path for building skb ...
2015-12-04Merge tag 'trace-v4.4-rc3' of ↵Linus Torvalds1-0/+16
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing fix from Steven Rostedt: "During the merge window I added a new file that is used to filter trace events on pids. It filters all events where only tasks with their pid in that file exists. It also handles the sched_switch and sched_wakeup trace events where the current task does not have its pid in the file, but the task either being switched to or awaken does. Unfortunately, I forgot about sched_wakeup_new and sched_waking. Both of these tracepoints use the same class as the sched_wakeup tracepoint, and they too should be included in what gets filtered by the set_event_pid file" * tag 'trace-v4.4-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: tracing: Add sched_wakeup_new and sched_waking tracepoints for pid filter
2015-12-03cgroup_pids: don't account for the root cgroupTejun Heo1-3/+4
Because accounting resources for the root cgroup sometimes incurs measureable overhead for workloads which don't care about cgroup and often ends up calculating a number which is available elsewhere in a slightly different form, cgroup is not in the business of providing system-wide statistics. The pids controller which was introduced recently was exposing "pids.current" at the root. This patch disable accounting for root cgroup and removes the file from the root directory. While this is a userland visible behavior change, pids has been available only in one version and was badly broken there, so I don't think this will be noticeable. If it turns out to be a problem, we can reinstate it for v1 hierarchies. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Aleksa Sarai <cyphar@cyphar.com>
2015-12-03cgroup: fix handling of multi-destination migration from subtree_control ↵Tejun Heo6-41/+75
enabling Consider the following v2 hierarchy. P0 (+memory) --- P1 (-memory) --- A \- B P0 has memory enabled in its subtree_control while P1 doesn't. If both A and B contain processes, they would belong to the memory css of P1. Now if memory is enabled on P1's subtree_control, memory csses should be created on both A and B and A's processes should be moved to the former and B's processes the latter. IOW, enabling controllers can cause atomic migrations into different csses. The core cgroup migration logic has been updated accordingly but the controller migration methods haven't and still assume that all tasks migrate to a single target css; furthermore, the methods were fed the css in which subtree_control was updated which is the parent of the target csses. pids controller depends on the migration methods to move charges and this made the controller attribute charges to the wrong csses often triggering the following warning by driving a counter negative. WARNING: CPU: 1 PID: 1 at kernel/cgroup_pids.c:97 pids_cancel.constprop.6+0x31/0x40() Modules linked in: CPU: 1 PID: 1 Comm: systemd Not tainted 4.4.0-rc1+ #29 ... ffffffff81f65382 ffff88007c043b90 ffffffff81551ffc 0000000000000000 ffff88007c043bc8 ffffffff810de202 ffff88007a752000 ffff88007a29ab00 ffff88007c043c80 ffff88007a1d8400 0000000000000001 ffff88007c043bd8 Call Trace: [<ffffffff81551ffc>] dump_stack+0x4e/0x82 [<ffffffff810de202>] warn_slowpath_common+0x82/0xc0 [<ffffffff810de2fa>] warn_slowpath_null+0x1a/0x20 [<ffffffff8118e031>] pids_cancel.constprop.6+0x31/0x40 [<ffffffff8118e0fd>] pids_can_attach+0x6d/0xf0 [<ffffffff81188a4c>] cgroup_taskset_migrate+0x6c/0x330 [<ffffffff81188e05>] cgroup_migrate+0xf5/0x190 [<ffffffff81189016>] cgroup_attach_task+0x176/0x200 [<ffffffff8118949d>] __cgroup_procs_write+0x2ad/0x460 [<ffffffff81189684>] cgroup_procs_write+0x14/0x20 [<ffffffff811854e5>] cgroup_file_write+0x35/0x1c0 [<ffffffff812e26f1>] kernfs_fop_write+0x141/0x190 [<ffffffff81265f88>] __vfs_write+0x28/0xe0 [<ffffffff812666fc>] vfs_write+0xac/0x1a0 [<ffffffff81267019>] SyS_write+0x49/0xb0 [<ffffffff81bcef32>] entry_SYSCALL_64_fastpath+0x12/0x76 This patch fixes the bug by removing @css parameter from the three migration methods, ->can_attach, ->cancel_attach() and ->attach() and updating cgroup_taskset iteration helpers also return the destination css in addition to the task being migrated. All controllers are updated accordingly. * Controllers which don't care whether there are one or multiple target csses can be converted trivially. cpu, io, freezer, perf, netclassid and netprio fall in this category. * cpuset's current implementation assumes that there's single source and destination and thus doesn't support v2 hierarchy already. The only change made by this patchset is how that single destination css is obtained. * memory migration path already doesn't do anything on v2. How the single destination css is obtained is updated and the prep stage of mem_cgroup_can_attach() is reordered to accomodate the change. * pids is the only controller which was affected by this bug. It now correctly handles multi-destination migrations and no longer causes counter underflow from incorrect accounting. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-and-tested-by: Daniel Wagner <daniel.wagner@bmw-carit.de> Cc: Aleksa Sarai <cyphar@cyphar.com>
2015-12-03cgroup_freezer: simplify propagation of CGROUP_FROZEN clearing in ↵Tejun Heo1-10/+7
freezer_attach() If one or more tasks get moved into a frozen css, the frozen state is cleared up from the destination css so that it can be reasserted once the migrated tasks are frozen. freezer_attach() implements this in two separate steps - clearing CGROUP_FROZEN on the target css while processing each task and propagating the clearing upwards after the task loop is done if necessary. This patch merges the two steps. Propagation now takes place inside the task loop. This simplifies the code and prepares it for the fix of multi-destination migration. Signed-off-by: Tejun Heo <tj@kernel.org>
2015-12-03bpf: fix allocation warnings in bpf maps and integer overflowAlexei Starovoitov3-12/+34
For large map->value_size the user space can trigger memory allocation warnings like: WARNING: CPU: 2 PID: 11122 at mm/page_alloc.c:2989 __alloc_pages_nodemask+0x695/0x14e0() Call Trace: [< inline >] __dump_stack lib/dump_stack.c:15 [<ffffffff82743b56>] dump_stack+0x68/0x92 lib/dump_stack.c:50 [<ffffffff81244ec9>] warn_slowpath_common+0xd9/0x140 kernel/panic.c:460 [<ffffffff812450f9>] warn_slowpath_null+0x29/0x30 kernel/panic.c:493 [< inline >] __alloc_pages_slowpath mm/page_alloc.c:2989 [<ffffffff81554e95>] __alloc_pages_nodemask+0x695/0x14e0 mm/page_alloc.c:3235 [<ffffffff816188fe>] alloc_pages_current+0xee/0x340 mm/mempolicy.c:2055 [< inline >] alloc_pages include/linux/gfp.h:451 [<ffffffff81550706>] alloc_kmem_pages+0x16/0xf0 mm/page_alloc.c:3414 [<ffffffff815a1c89>] kmalloc_order+0x19/0x60 mm/slab_common.c:1007 [<ffffffff815a1cef>] kmalloc_order_trace+0x1f/0xa0 mm/slab_common.c:1018 [< inline >] kmalloc_large include/linux/slab.h:390 [<ffffffff81627784>] __kmalloc+0x234/0x250 mm/slub.c:3525 [< inline >] kmalloc include/linux/slab.h:463 [< inline >] map_update_elem kernel/bpf/syscall.c:288 [< inline >] SYSC_bpf kernel/bpf/syscall.c:744 To avoid never succeeding kmalloc with order >= MAX_ORDER check that elem->value_size and computed elem_size are within limits for both hash and array type maps. Also add __GFP_NOWARN to kmalloc(value_size | elem_size) to avoid OOM warnings. Note kmalloc(key_size) is highly unlikely to trigger OOM, since key_size <= 512, so keep those kmalloc-s as-is. Large value_size can cause integer overflows in elem_size and map.pages formulas, so check for that as well. Fixes: aaac3ba95e4c ("bpf: charge user for creation of BPF maps and programs") Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-02bpf, array: fix heap out-of-bounds access when updating elementsDaniel Borkmann1-1/+1
During own review but also reported by Dmitry's syzkaller [1] it has been noticed that we trigger a heap out-of-bounds access on eBPF array maps when updating elements. This happens with each map whose map->value_size (specified during map creation time) is not multiple of 8 bytes. In array_map_alloc(), elem_size is round_up(attr->value_size, 8) and used to align array map slots for faster access. However, in function array_map_update_elem(), we update the element as ... memcpy(array->value + array->elem_size * index, value, array->elem_size); ... where we access 'value' out-of-bounds, since it was allocated from map_update_elem() from syscall side as kmalloc(map->value_size, GFP_USER) and later on copied through copy_from_user(value, uvalue, map->value_size). Thus, up to 7 bytes, we can access out-of-bounds. Same could happen from within an eBPF program, where in worst case we access beyond an eBPF program's designated stack. Since 1be7f75d1668 ("bpf: enable non-root eBPF programs") didn't hit an official release yet, it only affects priviledged users. In case of array_map_lookup_elem(), the verifier prevents eBPF programs from accessing beyond map->value_size through check_map_access(). Also from syscall side map_lookup_elem() only copies map->value_size back to user, so nothing could leak. [1] http://github.com/google/syzkaller Fixes: 28fbcfa08d8e ("bpf: add array type of eBPF maps") Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-02tracing: Add sched_wakeup_new and sched_waking tracepoints for pid filterSteven Rostedt (Red Hat)1-0/+16
The set_event_pid filter relies on attaching to the sched_switch and sched_wakeup tracepoints to see if it should filter the tracing on schedule tracepoints. By adding the callbacks to sched_wakeup, pids in the set_event_pid file will trace the wakeups of those tasks with those pids. But sched_wakeup_new and sched_waking were missed. These two should also be traced. Luckily, these tracepoints share the same class as sched_wakeup which means they can use the same pre and post callbacks as sched_wakeup does. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-12-01Merge tag 'trace-v4.4-rc2' of ↵Linus Torvalds1-8/+9
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing fixes from Steven Rostedt: "I found two minor bugs while doing development on the ring buffer code. The first is something that's been there since its creation. If a reader reads a page out of the ring buffer before there's any events on it, it can get an out of date timestamp for that event. It may be off by a few microseconds, more if the first event gets discarded. The fix was to only update the reader time stamp when it actually sees an event on the page, instead of just reading the timestamp from the page even if it has no events on it. That timestamp is still volatile until an event is present. The second bug is more recent. Instead of passing around parameters a descriptor was made and the parameters are passed via a single descriptor. This simplified the code a bit. But there was one place that expected the parameter to be passed by value not reference (which a descriptor now does). And it added to the length of the event, which may be ignored later, but the length should not have been increased. The only real problem with this bug is that it may allocate more than was needed for the event" * tag 'trace-v4.4-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: ring-buffer: Put back the length if crossed page with add_timestamp ring-buffer: Update read stamp with first real commit on page
2015-11-30cgroup: pids: kill pids_fork(), simplify pids_can_fork() and pids_cancel_fork()Oleg Nesterov1-31/+10
Now that we know that the forking task can't migrate amd the child is always moved to the same cgroup by cgroup_post_fork()->css_set_move_task() we can change pids_can_fork() and pids_cancel_fork() to just use task_css(current). And since we no longer need to pin this css, we can remove pid_fork(). Note: the patch uses task_css_check(true), perhaps it makes sense to add a helper or change task_css_set_check() to take cgroup_threadgroup_rwsem into account. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Zefan Li <lizefan@huawei.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2015-11-30cgroup: pids: fix race between cgroup_post_fork() and cgroup_migrate()Oleg Nesterov2-25/+5
If the new child migrates to another cgroup before cgroup_post_fork() calls subsys->fork(), then both pids_can_attach() and pids_fork() will do the same pids_uncharge(old_pids) + pids_charge(pids) sequence twice. Change copy_process() to call threadgroup_change_begin/threadgroup_change_end unconditionally. percpu_down_read() is cheap and this allows other cleanups, see the next changes. Also, this way we can unify cgroup_threadgroup_rwsem and dup_mmap_sem. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Zefan Li <lizefan@huawei.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2015-11-30cgroup: make css_set pin its css's to avoid use-afer-freeTejun Heo1-4/+10
A css_set represents the relationship between a set of tasks and css's. css_set never pinned the associated css's. This was okay because tasks used to always disassociate immediately (in RCU sense) - either a task is moved to a different css_set or exits and never accesses css_set again. Unfortunately, afcf6c8b7544 ("cgroup: add cgroup_subsys->free() method and use it to fix pids controller") and patches leading up to it made a zombie hold onto its css_set and deref the associated css's on its release. Nothing pins the css's after exit and it might have already been freed leading to use-after-free. general protection fault: 0000 [#1] PREEMPT SMP task: ffffffff81bf2500 ti: ffffffff81be4000 task.ti: ffffffff81be4000 RIP: 0010:[<ffffffff810fa205>] [<ffffffff810fa205>] pids_cancel.constprop.4+0x5/0x40 ... Call Trace: <IRQ> [<ffffffff810fb02d>] ? pids_free+0x3d/0xa0 [<ffffffff810f8893>] cgroup_free+0x53/0xe0 [<ffffffff8104ed62>] __put_task_struct+0x42/0x130 [<ffffffff81053557>] delayed_put_task_struct+0x77/0x130 [<ffffffff810c6b34>] rcu_process_callbacks+0x2f4/0x820 [<ffffffff810c6af3>] ? rcu_process_callbacks+0x2b3/0x820 [<ffffffff81056e54>] __do_softirq+0xd4/0x460 [<ffffffff81057369>] irq_exit+0x89/0xa0 [<ffffffff81876212>] smp_apic_timer_interrupt+0x42/0x50 [<ffffffff818747f4>] apic_timer_interrupt+0x84/0x90 <EOI> ... Code: 5b 5d c3 48 89 df 48 c7 c2 c9 f9 ae 81 48 c7 c6 91 2c ae 81 e8 1d 94 0e 00 31 c0 5b 5d c3 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 <f0> 48 83 87 e0 00 00 00 ff 78 01 c3 80 3d 08 7a c1 00 00 74 02 RIP [<ffffffff810fa205>] pids_cancel.constprop.4+0x5/0x40 RSP <ffff88001fc03e20> ---[ end trace 89a4a4b916b90c49 ]--- Kernel panic - not syncing: Fatal exception in interrupt Kernel Offset: disabled ---[ end Kernel panic - not syncing: Fatal exception in interrupt Fix it by making css_set pin the associate css's until its release. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Dave Jones <davej@codemonkey.org.uk> Reported-by: Daniel Wagner <daniel.wagner@bmw-carit.de> Link: http://lkml.kernel.org/g/20151120041836.GA18390@codemonkey.org.uk Link: http://lkml.kernel.org/g/5652D448.3080002@bmw-carit.de Fixes: afcf6c8b7544 ("cgroup: add cgroup_subsys->free() method and use it to fix pids controller")
2015-11-25bpf: fix clearing on persistent program array mapsDaniel Borkmann3-16/+29
Currently, when having map file descriptors pointing to program arrays, there's still the issue that we unconditionally flush program array contents via bpf_fd_array_map_clear() in bpf_map_release(). This happens when such a file descriptor is released and is independent of the map's refcount. Having this flush independent of the refcount is for a reason: there can be arbitrary complex dependency chains among tail calls, also circular ones (direct or indirect, nesting limit determined during runtime), and we need to make sure that the map drops all references to eBPF programs it holds, so that the map's refcount can eventually drop to zero and initiate its freeing. Btw, a walk of the whole dependency graph would not be possible for various reasons, one being complexity and another one inconsistency, i.e. new programs can be added to parts of the graph at any time, so there's no guaranteed consistent state for the time of such a walk. Now, the program array pinning itself works, but the issue is that each derived file descriptor on close would nevertheless call unconditionally into bpf_fd_array_map_clear(). Instead, keep track of users and postpone this flush until the last reference to a user is dropped. As this only concerns a subset of references (f.e. a prog array could hold a program that itself has reference on the prog array holding it, etc), we need to track them separately. Short analysis on the refcounting: on map creation time usercnt will be one, so there's no change in behaviour for bpf_map_release(), if unpinned. If we already fail in map_create(), we are immediately freed, and no file descriptor has been made public yet. In bpf_obj_pin_user(), we need to probe for a possible map in bpf_fd_probe_obj() already with a usercnt reference, so before we drop the reference on the fd with fdput(). Therefore, if actual pinning fails, we need to drop that reference again in bpf_any_put(), otherwise we keep holding it. When last reference drops on the inode, the bpf_any_put() in bpf_evict_inode() will take care of dropping the usercnt again. In the bpf_obj_get_user() case, the bpf_any_get() will grab a reference on the usercnt, still at a time when we have the reference on the path. Should we later on fail to grab a new file descriptor, bpf_any_put() will drop it, otherwise we hold it until bpf_map_release() time. Joint work with Alexei. Fixes: b2197755b263 ("bpf: add support for persistent maps/progs") Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-11-24pidns: fix NULL dereference in __task_pid_nr_ns()Eric Dumazet1-2/+2
I got a crash during a "perf top" session that was caused by a race in __task_pid_nr_ns() : pid_nr_ns() was inlined, but apparently compiler chose to read task->pids[type].pid twice, and the pid->level dereference crashed because we got a NULL pointer at the second read : if (pid && ns->level <= pid->level) { // CRASH Just use RCU API properly to solve this race, and not worry about "perf top" crashing hosts :( get_task_pid() can benefit from same fix. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-11-24ring-buffer: Put back the length if crossed page with add_timestampSteven Rostedt (Red Hat)1-1/+4
Commit fcc742eaad7c "ring-buffer: Add event descriptor to simplify passing data" added a descriptor that holds various data instead of passing around several variables through parameters. The problem was that one of the parameters was modified in a function and the code was designed not to have an effect on that modified parameter. Now that the parameter is a descriptor and any modifications to it are non-volatile, the size of the data could be unnecessarily expanded. Remove the extra space added if a timestamp was added and the event went across the page. Cc: stable@vger.kernel.org # 4.3+ Fixes: fcc742eaad7c "ring-buffer: Add event descriptor to simplify passing data" Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-11-24ring-buffer: Update read stamp with first real commit on pageSteven Rostedt (Red Hat)1-7/+5
Do not update the read stamp after swapping out the reader page from the write buffer. If the reader page is swapped out of the buffer before an event is written to it, then the read_stamp may get an out of date timestamp, as the page timestamp is updated on the first commit to that page. rb_get_reader_page() only returns a page if it has an event on it, otherwise it will return NULL. At that point, check if the page being returned has events and has not been read yet. Then at that point update the read_stamp to match the time stamp of the reader page. Cc: stable@vger.kernel.org # 2.6.30+ Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-11-23treewide: Remove old email addressPeter Zijlstra11-11/+11
There were still a number of references to my old Red Hat email address in the kernel source. Remove these while keeping the Red Hat copyright notices intact. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-11-23sched/rt: Hide the push_irq_work_func() declarationArnd Bergmann1-1/+1
The push_irq_work_func() function is conditionally defined only when both CONFIG_SMP and HAVE_RT_PUSH_IPI are defined, but the forward declaration remains visibile without HAVE_RT_PUSH_IPI, causing a gcc warning in ARM64 allnoconfig: kernel/sched/rt.c:68:13: warning: 'push_irq_work_func' declared 'static' but never defined [-Wunused-function] This changes the code to use the same condition for both the declaration and the function definition, which gets rid of the warning. As Peter Zijlstra, we can possibly get rid of the whole HAVE_RT_PUSH_IPI thing after: 8053871d0f7f ("smp: Fix smp_call_function_single_async() locking") Until that is done, this patch can be used to avoid the warning. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Steven Rostedt <rostedt@goodmis.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: b6366f048e0c ("sched/rt: Use IPI to trigger RT task push migration instead of pulling") Link: http://lkml.kernel.org/r/3828565.oKfGk7yNIT@wuerfel Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-11-23perf/core: Robustify the perf_cgroup_from_task() RCU checksStephane Eranian1-7/+13
This patch reinforces the lockdep checks performed by perf_cgroup_from_tsk() by passing the perf_event_context whenever possible. It is okay to not hold the RCU read lock when we know we hold the ctx->lock. This patch makes sure this property holds. In some functions, such as perf_cgroup_sched_in(), we do not pass the context because we are sure we are holding the RCU read lock. Signed-off-by: Stephane Eranian <eranian@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: edumazet@google.com Link: http://lkml.kernel.org/r/1447322404-10920-3-git-send-email-eranian@google.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-11-23perf/core: Fix RCU problem with cgroup context switching codeStephane Eranian1-3/+8
The RCU checker detected RCU violation in the cgroup switching routines perf_cgroup_sched_in() and perf_cgroup_sched_out(). We were dereferencing cgroup from task without holding the RCU lock. Fix this by holding the RCU read lock. We move the locking from perf_cgroup_switch() to avoid double locking. Signed-off-by: Stephane Eranian <eranian@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: edumazet@google.com Link: http://lkml.kernel.org/r/1447322404-10920-2-git-send-email-eranian@google.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-11-21kernel/panic.c: turn off locks debug before releasing console lockVitaly Kuznetsov1-1/+4
Commit 08d78658f393 ("panic: release stale console lock to always get the logbuf printed out") introduced an unwanted bad unlock balance report when panic() is called directly and not from OOPS (e.g. from out_of_memory()). The difference is that in case of OOPS we disable locks debug in oops_enter() and on direct panic call nobody does that. Fixes: 08d78658f393 ("panic: release stale console lock to always get the logbuf printed out") Reported-by: kernel test robot <ying.huang@linux.intel.com> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Baoquan He <bhe@redhat.com> Cc: Prarit Bhargava <prarit@redhat.com> Cc: Xie XiuQi <xiexiuqi@huawei.com> Cc: Seth Jennings <sjenning@redhat.com> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Jan Kara <jack@suse.cz> Cc: Petr Mladek <pmladek@suse.cz> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-11-21kernel/signal.c: unexport sigsuspend()Richard Weinberger1-1/+1
sigsuspend() is nowhere used except in signal.c itself, so we can mark it static do not pollute the global namespace. But this patch is more than a boring cleanup patch, it fixes a real issue on UserModeLinux. UML has a special console driver to display ttys using xterm, or other terminal emulators, on the host side. Vegard reported that sometimes UML is unable to spawn a xterm and he's facing the following warning: WARNING: CPU: 0 PID: 908 at include/linux/thread_info.h:128 sigsuspend+0xab/0xc0() It turned out that this warning makes absolutely no sense as the UML xterm code calls sigsuspend() on the host side, at least it tries. But as the kernel itself offers a sigsuspend() symbol the linker choose this one instead of the glibc wrapper. Interestingly this code used to work since ever but always blocked signals on the wrong side. Some recent kernel change made the WARN_ON() trigger and uncovered the bug. It is a wonderful example of how much works by chance on computers. :-) Fixes: 68f3f16d9ad0f1 ("new helper: sigsuspend()") Signed-off-by: Richard Weinberger <richard@nod.at> Reported-by: Vegard Nossum <vegard.nossum@oracle.com> Tested-by: Vegard Nossum <vegard.nossum@oracle.com> Acked-by: Oleg Nesterov <oleg@redhat.com> Cc: <stable@vger.kernel.org> [3.5+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-11-19Merge branch 'for-linus' of ↵Linus Torvalds1-0/+6
git://git.kernel.org/pub/scm/linux/kernel/git/jikos/livepatching Pull livepatching fix from Jiri Kosina: "A fix for module handling in case kASLR has been enabled, from Zhou Chengming" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/livepatching: livepatch: x86: fix relocation computation with kASLR
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