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2016-06-29Merge branch 'stable-4.7' of git:// Torvalds3-4/+25
Pull audit fixes from Paul Moore: "Two small patches to fix audit problems in 4.7-rcX: the first fixes a potential kref leak, the second removes some header file noise. The first is an important bug fix that really should go in before 4.7 is released, the second is not critical, but falls into the very-nice- to-have category so I'm including in the pull request. Both patches are straightforward, self-contained, and pass our testsuite without problem" * 'stable-4.7' of git:// audit: move audit_get_tty to reduce scope and kabi changes audit: move calcs after alloc and check when logging set loginuid
2016-06-29Merge git:// Torvalds3-37/+16
Pull networking fixes from David Miller: "I've been traveling so this accumulates more than week or so of bug fixing. It perhaps looks a little worse than it really is. 1) Fix deadlock in ath10k driver, from Ben Greear. 2) Increase scan timeout in iwlwifi, from Luca Coelho. 3) Unbreak STP by properly reinjecting STP packets back into the stack. Regression fix from Ido Schimmel. 4) Mediatek driver fixes (missing malloc failure checks, leaking of scratch memory, wrong indexing when mapping TX buffers, etc.) from John Crispin. 5) Fix endianness bug in icmpv6_err() handler, from Hannes Frederic Sowa. 6) Fix hashing of flows in UDP in the ruseport case, from Xuemin Su. 7) Fix netlink notifications in ovs for tunnels, delete link messages are never emitted because of how the device registry state is handled. From Nicolas Dichtel. 8) Conntrack module leaks kmemcache on unload, from Florian Westphal. 9) Prevent endless jump loops in nft rules, from Liping Zhang and Pablo Neira Ayuso. 10) Not early enough spinlock initialization in mlx4, from Eric Dumazet. 11) Bind refcount leak in act_ipt, from Cong WANG. 12) Missing RCU locking in HTB scheduler, from Florian Westphal. 13) Several small MACSEC bug fixes from Sabrina Dubroca (missing RCU barrier, using heap for SG and IV, and erroneous use of async flag when allocating AEAD conext.) 14) RCU handling fix in TIPC, from Ying Xue. 15) Pass correct protocol down into ipv4_{update_pmtu,redirect}() in SIT driver, from Simon Horman. 16) Socket timer deadlock fix in TIPC from Jon Paul Maloy. 17) Fix potential deadlock in team enslave, from Ido Schimmel. 18) Memory leak in KCM procfs handling, from Jiri Slaby. 19) ESN generation fix in ipv4 ESP, from Herbert Xu. 20) Fix GFP_KERNEL allocations with locks held in act_ife, from Cong WANG. 21) Use after free in netem, from Eric Dumazet. 22) Uninitialized last assert time in multicast router code, from Tom Goff. 23) Skip raw sockets in sock_diag destruction broadcast, from Willem de Bruijn. 24) Fix link status reporting in thunderx, from Sunil Goutham. 25) Limit resegmentation of retransmit queue so that we do not retransmit too large GSO frames. From Eric Dumazet. 26) Delay bpf program release after grace period, from Daniel Borkmann" * git:// (141 commits) openvswitch: fix conntrack netlink event delivery qed: Protect the doorbell BAR with the write barriers. neigh: Explicitly declare RCU-bh read side critical section in neigh_xmit() e1000e: keep VLAN interfaces functional after rxvlan off cfg80211: fix proto in ieee80211_data_to_8023 for frames without LLC header qlcnic: use the correct ring in qlcnic_83xx_process_rcv_ring_diag() bpf, perf: delay release of BPF prog after grace period net: bridge: fix vlan stats continue counter tcp: do not send too big packets at retransmit time ibmvnic: fix to use list_for_each_safe() when delete items net: thunderx: Fix TL4 configuration for secondary Qsets net: thunderx: Fix link status reporting net/mlx5e: Reorganize ethtool statistics net/mlx5e: Fix number of PFC counters reported to ethtool net/mlx5e: Prevent adding the same vxlan port net/mlx5e: Check for BlueFlame capability before allocating SQ uar net/mlx5e: Change enum to better reflect usage net/mlx5: Add ConnectX-5 PCIe 4.0 to list of supported devices net/mlx5: Update command strings net: marvell: Add separate config ANEG function for Marvell 88E1111 ...
2016-06-29Merge branch 'for-4.7-fixes' of ↵Linus Torvalds1-72/+76
git:// Pull cgroup fixes from Tejun Heo: "Three fix patches. Two are for cgroup / css init failure path. The last one makes css_set_lock irq-safe as the deadline scheduler ends up calling put_css_set() from irq context" * 'for-4.7-fixes' of git:// cgroup: Disable IRQs while holding css_set_lock cgroup: set css->id to -1 during init cgroup: remove redundant cleanup in css_create
2016-06-29bpf, perf: delay release of BPF prog after grace periodDaniel Borkmann1-1/+1
Commit dead9f29ddcc ("perf: Fix race in BPF program unregister") moved destruction of BPF program from free_event_rcu() callback to __free_event(), which is problematic if used with tail calls: if prog A is attached as trace event directly, but at the same time present in a tail call map used by another trace event program elsewhere, then we need to delay destruction via RCU grace period since it can still be in use by the program doing the tail call (the prog first needs to be dropped from the tail call map, then trace event with prog A attached destroyed, so we get immediate destruction). Fixes: dead9f29ddcc ("perf: Fix race in BPF program unregister") Signed-off-by: Daniel Borkmann <> Acked-by: Alexei Starovoitov <> Cc: Jann Horn <> Signed-off-by: David S. Miller <>
2016-06-28audit: move audit_get_tty to reduce scope and kabi changesRichard Guy Briggs3-1/+21
The only users of audit_get_tty and audit_put_tty are internal to audit, so move it out of include/linux/audit.h to kernel.h and create a proper function rather than inlining it. This also reduces kABI changes. Suggested-by: Paul Moore <> Signed-off-by: Richard Guy Briggs <> [PM: line wrapped description] Signed-off-by: Paul Moore <>
2016-06-28audit: move calcs after alloc and check when logging set loginuidRichard Guy Briggs1-3/+4
Move the calculations of values after the allocation in case the allocation fails. This avoids wasting effort in the rare case that it fails, but more importantly saves us extra logic to release the tty ref. Signed-off-by: Richard Guy Briggs <> Signed-off-by: Paul Moore <>
2016-06-25Merge branch 'sched-urgent-for-linus' of ↵Linus Torvalds3-21/+66
git:// Pull scheduler fixes from Thomas Gleixner: "A couple of scheduler fixes: - force watchdog reset while processing sysrq-w - fix a deadlock when enabling trace events in the scheduler - fixes to the throttled next buddy logic - fixes for the average accounting (missing serialization and underflow handling) - allow kernel threads for fallback to online but not active cpus" * 'sched-urgent-for-linus' of git:// sched/core: Allow kthreads to fall back to online && !active cpus sched/fair: Do not announce throttled next buddy in dequeue_task_fair() sched/fair: Initialize throttle_count for new task-groups lazily sched/fair: Fix cfs_rq avg tracking underflow kernel/sysrq, watchdog, sched/core: Reset watchdog on all CPUs while processing sysrq-w sched/debug: Fix deadlock when enabling sched events sched/fair: Fix post_init_entity_util_avg() serialization
2016-06-25Merge branch 'locking-urgent-for-linus' of ↵Linus Torvalds1-3/+33
git:// Pull locking fix from Thomas Gleixner: "A single fix to address a race in the static key logic" * 'locking-urgent-for-linus' of git:// locking/static_key: Fix concurrent static_key_slow_inc()
2016-06-25Fix build break in fork.c when THREAD_SIZE < PAGE_SIZEMichael Ellerman1-2/+2
Commit b235beea9e99 ("Clarify naming of thread info/stack allocators") breaks the build on some powerpc configs, where THREAD_SIZE < PAGE_SIZE: kernel/fork.c:235:2: error: implicit declaration of function 'free_thread_stack' kernel/fork.c:355:8: error: assignment from incompatible pointer type stack = alloc_thread_stack_node(tsk, node); ^ Fix it by renaming free_stack() to free_thread_stack(), and updating the return type of alloc_thread_stack_node(). Fixes: b235beea9e99 ("Clarify naming of thread info/stack allocators") Signed-off-by: Michael Ellerman <> Signed-off-by: Linus Torvalds <>
2016-06-24Merge branch 'akpm' (patches from Andrew)Linus Torvalds1-0/+12
Merge misc fixes from Andrew Morton: "Two weeks worth of fixes here" * emailed patches from Andrew Morton <>: (41 commits) init/main.c: fix initcall_blacklisted on ia64, ppc64 and parisc64 autofs: don't get stuck in a loop if vfs_write() returns an error mm/page_owner: avoid null pointer dereference tools/vm/slabinfo: fix spelling mistake: "Ocurrences" -> "Occurrences" fs/nilfs2: fix potential underflow in call to crc32_le oom, suspend: fix oom_reaper vs. oom_killer_disable race ocfs2: disable BUG assertions in reading blocks mm, compaction: abort free scanner if split fails mm: prevent KASAN false positives in kmemleak mm/hugetlb: clear compound_mapcount when freeing gigantic pages mm/swap.c: flush lru pvecs on compound page arrival memcg: css_alloc should return an ERR_PTR value on error memcg: mem_cgroup_migrate() may be called with irq disabled hugetlb: fix nr_pmds accounting with shared page tables Revert "mm: disable fault around on emulated access bit architecture" Revert "mm: make faultaround produce old ptes" mailmap: add Boris Brezillon's email mailmap: add Antoine Tenart's email mm, sl[au]b: add __GFP_ATOMIC to the GFP reclaim mask mm: mempool: kasan: don't poot mempool objects in quarantine ...
2016-06-24oom, suspend: fix oom_reaper vs. oom_killer_disable raceMichal Hocko1-0/+12
Tetsuo has reported the following potential oom_killer_disable vs. oom_reaper race: (1) freeze_processes() starts freezing user space threads. (2) Somebody (maybe a kenrel thread) calls out_of_memory(). (3) The OOM killer calls mark_oom_victim() on a user space thread P1 which is already in __refrigerator(). (4) oom_killer_disable() sets oom_killer_disabled = true. (5) P1 leaves __refrigerator() and enters do_exit(). (6) The OOM reaper calls exit_oom_victim(P1) before P1 can call exit_oom_victim(P1). (7) oom_killer_disable() returns while P1 not yet finished (8) P1 perform IO/interfere with the freezer. This situation is unfortunate. We cannot move oom_killer_disable after all the freezable kernel threads are frozen because the oom victim might depend on some of those kthreads to make a forward progress to exit so we could deadlock. It is also far from trivial to teach the oom_reaper to not call exit_oom_victim() because then we would lose a guarantee of the OOM killer and oom_killer_disable forward progress because exit_mm->mmput might block and never call exit_oom_victim. It seems the easiest way forward is to workaround this race by calling try_to_freeze_tasks again after oom_killer_disable. This will make sure that all the tasks are frozen or it bails out. Fixes: 449d777d7ad6 ("mm, oom_reaper: clear TIF_MEMDIE for all tasks queued for oom_reaper") Link: Signed-off-by: Michal Hocko <> Reported-by: Tetsuo Handa <> Cc: "Rafael J. Wysocki" <> Signed-off-by: Andrew Morton <> Signed-off-by: Linus Torvalds <>
2016-06-24Clarify naming of thread info/stack allocatorsLinus Torvalds1-25/+25
We've had the thread info allocated together with the thread stack for most architectures for a long time (since the thread_info was split off from the task struct), but that is about to change. But the patches that move the thread info to be off-stack (and a part of the task struct instead) made it clear how confused the allocator and freeing functions are. Because the common case was that we share an allocation with the thread stack and the thread_info, the two pointers were identical. That identity then meant that we would have things like ti = alloc_thread_info_node(tsk, node); ... tsk->stack = ti; which certainly _worked_ (since stack and thread_info have the same value), but is rather confusing: why are we assigning a thread_info to the stack? And if we move the thread_info away, the "confusing" code just gets to be entirely bogus. So remove all this confusion, and make it clear that we are doing the stack allocation by renaming and clarifying the function names to be about the stack. The fact that the thread_info then shares the allocation is an implementation detail, and not really about the allocation itself. This is a pure renaming and type fix: we pass in the same pointer, it's just that we clarify what the pointer means. The ia64 code that actually only has one single allocation (for all of task_struct, thread_info and kernel thread stack) now looks a bit odd, but since "tsk->stack" is actually not even used there, that oddity doesn't matter. It would be a separate thing to clean that up, I intentionally left the ia64 changes as a pure brute-force renaming and type change. Acked-by: Andy Lutomirski <> Signed-off-by: Linus Torvalds <>
2016-06-24sched/core: Allow kthreads to fall back to online && !active cpusTejun Heo1-1/+3
During CPU hotplug, CPU_ONLINE callbacks are run while the CPU is online but not active. A CPU_ONLINE callback may create or bind a kthread so that its cpus_allowed mask only allows the CPU which is being brought online. The kthread may start executing before the CPU is made active and can end up in select_fallback_rq(). In such cases, the expected behavior is selecting the CPU which is coming online; however, because select_fallback_rq() only chooses from active CPUs, it determines that the task doesn't have any viable CPU in its allowed mask and ends up overriding it to cpu_possible_mask. CPU_ONLINE callbacks should be able to put kthreads on the CPU which is coming online. Update select_fallback_rq() so that it follows cpu_online() rather than cpu_active() for kthreads. Reported-by: Gautham R Shenoy <> Tested-by: Gautham R. Shenoy <> Signed-off-by: Tejun Heo <> Signed-off-by: Peter Zijlstra (Intel) <> Cc: Abdul Haleem <> Cc: Aneesh Kumar <> Cc: Linus Torvalds <> Cc: Michael Ellerman <> Cc: Peter Zijlstra <> Cc: Thomas Gleixner <> Cc: Cc: Link: Signed-off-by: Ingo Molnar <>
2016-06-24sched/fair: Do not announce throttled next buddy in dequeue_task_fair()Konstantin Khlebnikov1-5/+4
Hierarchy could be already throttled at this point. Throttled next buddy could trigger a NULL pointer dereference in pick_next_task_fair(). Signed-off-by: Konstantin Khlebnikov <> Signed-off-by: Peter Zijlstra (Intel) <> Reviewed-by: Ben Segall <> Cc: Linus Torvalds <> Cc: Peter Zijlstra <> Cc: Thomas Gleixner <> Link: Signed-off-by: Ingo Molnar <>
2016-06-24sched/fair: Initialize throttle_count for new task-groups lazilyKonstantin Khlebnikov2-1/+21
Cgroup created inside throttled group must inherit current throttle_count. Broken throttle_count allows to nominate throttled entries as a next buddy, later this leads to null pointer dereference in pick_next_task_fair(). This patch initialize cfs_rq->throttle_count at first enqueue: laziness allows to skip locking all rq at group creation. Lazy approach also allows to skip full sub-tree scan at throttling hierarchy (not in this patch). Signed-off-by: Konstantin Khlebnikov <> Signed-off-by: Peter Zijlstra (Intel) <> Cc: Linus Torvalds <> Cc: Peter Zijlstra <> Cc: Thomas Gleixner <> Cc: Link: Signed-off-by: Ingo Molnar <>
2016-06-24locking/static_key: Fix concurrent static_key_slow_inc()Paolo Bonzini1-3/+33
The following scenario is possible: CPU 1 CPU 2 static_key_slow_inc() atomic_inc_not_zero() -> key.enabled == 0, no increment jump_label_lock() atomic_inc_return() -> key.enabled == 1 now static_key_slow_inc() atomic_inc_not_zero() -> key.enabled == 1, inc to 2 return ** static key is wrong! jump_label_update() jump_label_unlock() Testing the static key at the point marked by (**) will follow the wrong path for jumps that have not been patched yet. This can actually happen when creating many KVM virtual machines with userspace LAPIC emulation; just run several copies of the following program: #include <fcntl.h> #include <unistd.h> #include <sys/ioctl.h> #include <linux/kvm.h> int main(void) { for (;;) { int kvmfd = open("/dev/kvm", O_RDONLY); int vmfd = ioctl(kvmfd, KVM_CREATE_VM, 0); close(ioctl(vmfd, KVM_CREATE_VCPU, 1)); close(vmfd); close(kvmfd); } return 0; } Every KVM_CREATE_VCPU ioctl will attempt a static_key_slow_inc() call. The static key's purpose is to skip NULL pointer checks and indeed one of the processes eventually dereferences NULL. As explained in the commit that introduced the bug: 706249c222f6 ("locking/static_keys: Rework update logic") jump_label_update() needs key.enabled to be true. The solution adopted here is to temporarily make key.enabled == -1, and use go down the slow path when key.enabled <= 0. Reported-by: Dmitry Vyukov <> Signed-off-by: Paolo Bonzini <> Signed-off-by: Peter Zijlstra (Intel) <> Cc: <> # v4.3+ Cc: Linus Torvalds <> Cc: Peter Zijlstra <> Cc: Thomas Gleixner <> Fixes: 706249c222f6 ("locking/static_keys: Rework update logic") Link: [ Small stylistic edits to the changelog and the code. ] Signed-off-by: Ingo Molnar <>
2016-06-23cgroup: Disable IRQs while holding css_set_lockDaniel Bristot de Oliveira1-68/+74
While testing the deadline scheduler + cgroup setup I hit this warning. [ 132.612935] ------------[ cut here ]------------ [ 132.612951] WARNING: CPU: 5 PID: 0 at kernel/softirq.c:150 __local_bh_enable_ip+0x6b/0x80 [ 132.612952] Modules linked in: (a ton of modules...) [ 132.612981] CPU: 5 PID: 0 Comm: swapper/5 Not tainted 4.7.0-rc2 #2 [ 132.612981] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.8.2-20150714_191134- 04/01/2014 [ 132.612982] 0000000000000086 45c8bb5effdd088b ffff88013fd43da0 ffffffff813d229e [ 132.612984] 0000000000000000 0000000000000000 ffff88013fd43de0 ffffffff810a652b [ 132.612985] 00000096811387b5 0000000000000200 ffff8800bab29d80 ffff880034c54c00 [ 132.612986] Call Trace: [ 132.612987] <IRQ> [<ffffffff813d229e>] dump_stack+0x63/0x85 [ 132.612994] [<ffffffff810a652b>] __warn+0xcb/0xf0 [ 132.612997] [<ffffffff810e76a0>] ? push_dl_task.part.32+0x170/0x170 [ 132.612999] [<ffffffff810a665d>] warn_slowpath_null+0x1d/0x20 [ 132.613000] [<ffffffff810aba5b>] __local_bh_enable_ip+0x6b/0x80 [ 132.613008] [<ffffffff817d6c8a>] _raw_write_unlock_bh+0x1a/0x20 [ 132.613010] [<ffffffff817d6c9e>] _raw_spin_unlock_bh+0xe/0x10 [ 132.613015] [<ffffffff811388ac>] put_css_set+0x5c/0x60 [ 132.613016] [<ffffffff8113dc7f>] cgroup_free+0x7f/0xa0 [ 132.613017] [<ffffffff810a3912>] __put_task_struct+0x42/0x140 [ 132.613018] [<ffffffff810e776a>] dl_task_timer+0xca/0x250 [ 132.613027] [<ffffffff810e76a0>] ? push_dl_task.part.32+0x170/0x170 [ 132.613030] [<ffffffff8111371e>] __hrtimer_run_queues+0xee/0x270 [ 132.613031] [<ffffffff81113ec8>] hrtimer_interrupt+0xa8/0x190 [ 132.613034] [<ffffffff81051a58>] local_apic_timer_interrupt+0x38/0x60 [ 132.613035] [<ffffffff817d9b0d>] smp_apic_timer_interrupt+0x3d/0x50 [ 132.613037] [<ffffffff817d7c5c>] apic_timer_interrupt+0x8c/0xa0 [ 132.613038] <EOI> [<ffffffff81063466>] ? native_safe_halt+0x6/0x10 [ 132.613043] [<ffffffff81037a4e>] default_idle+0x1e/0xd0 [ 132.613044] [<ffffffff810381cf>] arch_cpu_idle+0xf/0x20 [ 132.613046] [<ffffffff810e8fda>] default_idle_call+0x2a/0x40 [ 132.613047] [<ffffffff810e92d7>] cpu_startup_entry+0x2e7/0x340 [ 132.613048] [<ffffffff81050235>] start_secondary+0x155/0x190 [ 132.613049] ---[ end trace f91934d162ce9977 ]--- The warn is the spin_(lock|unlock)_bh(&css_set_lock) in the interrupt context. Converting the spin_lock_bh to spin_lock_irq(save) to avoid this problem - and other problems of sharing a spinlock with an interrupt. Cc: Tejun Heo <> Cc: Li Zefan <> Cc: Johannes Weiner <> Cc: Juri Lelli <> Cc: Steven Rostedt <> Cc: Cc: # 4.5+ Cc: Reviewed-by: Rik van Riel <> Reviewed-by: "Luis Claudio R. Goncalves" <> Signed-off-by: Daniel Bristot de Oliveira <> Acked-by: Zefan Li <> Signed-off-by: Tejun Heo <>
2016-06-23locking: avoid passing around 'thread_info' in mutex debugging codeLinus Torvalds4-12/+12
None of the code actually wants a thread_info, it all wants a task_struct, and it's just converting back and forth between the two ("ti->task" to get the task_struct from the thread_info, and "task_thread_info(task)" to go the other way). No semantic change. Acked-by: Peter Zijlstra <> Signed-off-by: Linus Torvalds <>
2016-06-20Merge tag 'trace-v4.7-rc3' of ↵Linus Torvalds1-1/+6
git:// Pull tracing fixes from Steven Rostedt: "Two fixes for the tracing system: - When trace_printk() is used with a non constant format descriptor, it adds a NULL pointer into the trace format section, and the code isn't prepared to deal with it. This bug appeared by a change that was added in v3.5. - The ftracetest (selftests section) can't handle testing histograms when histograms are not configured. Currently it shows that they fail the test, when they should state that they are unsupported. This bug was added in the 4.7 merge window with the addition of the historgram code" * tag 'trace-v4.7-rc3' of git:// ftracetest: Fix hist unsupported result in hist selftests tracing: Handle NULL formats in hold_module_trace_bprintk_format()
2016-06-20tracing: Handle NULL formats in hold_module_trace_bprintk_format()Steven Rostedt (Red Hat)1-1/+6
If a task uses a non constant string for the format parameter in trace_printk(), then the trace_printk_fmt variable is set to NULL. This variable is then saved in the __trace_printk_fmt section. The function hold_module_trace_bprintk_format() checks to see if duplicate formats are used by modules, and reuses them if so (saves them to the list if it is new). But this function calls lookup_format() that does a strcmp() to the value (which is now NULL) and can cause a kernel oops. This wasn't an issue till 3debb0a9ddb ("tracing: Fix trace_printk() to print when not using bprintk()") which added "__used" to the trace_printk_fmt variable, and before that, the kernel simply optimized it out (no NULL value was saved). The fix is simply to handle the NULL pointer in lookup_format() and have the caller ignore the value if it was NULL. Link: Reported-by: xingzhen <> Acked-by: Namhyung Kim <> Fixes: 3debb0a9ddb ("tracing: Fix trace_printk() to print when not using bprintk()") Cc: # v3.5+ Signed-off-by: Steven Rostedt <>
2016-06-20sched/fair: Fix cfs_rq avg tracking underflowPeter Zijlstra1-8/+25
As per commit: b7fa30c9cc48 ("sched/fair: Fix post_init_entity_util_avg() serialization") > the code generated from update_cfs_rq_load_avg(): > > if (atomic_long_read(&cfs_rq->removed_load_avg)) { > s64 r = atomic_long_xchg(&cfs_rq->removed_load_avg, 0); > sa->load_avg = max_t(long, sa->load_avg - r, 0); > sa->load_sum = max_t(s64, sa->load_sum - r * LOAD_AVG_MAX, 0); > removed_load = 1; > } > > turns into: > > ffffffff81087064: 49 8b 85 98 00 00 00 mov 0x98(%r13),%rax > ffffffff8108706b: 48 85 c0 test %rax,%rax > ffffffff8108706e: 74 40 je ffffffff810870b0 <update_blocked_averages+0xc0> > ffffffff81087070: 4c 89 f8 mov %r15,%rax > ffffffff81087073: 49 87 85 98 00 00 00 xchg %rax,0x98(%r13) > ffffffff8108707a: 49 29 45 70 sub %rax,0x70(%r13) > ffffffff8108707e: 4c 89 f9 mov %r15,%rcx > ffffffff81087081: bb 01 00 00 00 mov $0x1,%ebx > ffffffff81087086: 49 83 7d 70 00 cmpq $0x0,0x70(%r13) > ffffffff8108708b: 49 0f 49 4d 70 cmovns 0x70(%r13),%rcx > > Which you'll note ends up with sa->load_avg -= r in memory at > ffffffff8108707a. So I _should_ have looked at other unserialized users of ->load_avg, but alas. Luckily nikbor reported a similar /0 from task_h_load() which instantly triggered recollection of this here problem. Aside from the intermediate value hitting memory and causing problems, there's another problem: the underflow detection relies on the signed bit. This reduces the effective width of the variables, IOW its effectively the same as having these variables be of signed type. This patch changes to a different means of unsigned underflow detection to not rely on the signed bit. This allows the variables to use the 'full' unsigned range. And it does so with explicit LOAD - STORE to ensure any intermediate value will never be visible in memory, allowing these unserialized loads. Note: GCC generates crap code for this, might warrant a look later. Note2: I say 'full' above, if we end up at U*_MAX we'll still explode; maybe we should do clamping on add too. Signed-off-by: Peter Zijlstra (Intel) <> Cc: Andrey Ryabinin <> Cc: Chris Wilson <> Cc: Linus Torvalds <> Cc: Mike Galbraith <> Cc: Peter Zijlstra <> Cc: Thomas Gleixner <> Cc: Yuyang Du <> Cc: Cc: Cc: Cc: Cc: Fixes: 9d89c257dfb9 ("sched/fair: Rewrite runnable load and utilization average tracking") Link: Signed-off-by: Ingo Molnar <>
2016-06-16cgroup: set css->id to -1 during initTejun Heo1-0/+1
If percpu_ref initialization fails during css_create(), the free path can end up trying to free css->id of zero. As ID 0 is unused, it doesn't cause a critical breakage but it does trigger a warning message. Fix it by setting css->id to -1 from init_and_link_css(). Signed-off-by: Tejun Heo <> Cc: Wenwei Tao <> Fixes: 01e586598b22 ("cgroup: release css->id after css_free") Cc: # v4.0+ Signed-off-by: Tejun Heo <>
2016-06-15bpf, trace: check event type in bpf_perf_event_readAlexei Starovoitov1-0/+4
similar to bpf_perf_event_output() the bpf_perf_event_read() helper needs to check the type of the perf_event before reading the counter. Fixes: a43eec304259 ("bpf: introduce bpf_perf_event_output() helper") Reported-by: Daniel Borkmann <> Signed-off-by: Alexei Starovoitov <> Acked-by: Daniel Borkmann <> Signed-off-by: David S. Miller <>
2016-06-15bpf: fix matching of data/data_end in verifierAlexei Starovoitov2-36/+11
The ctx structure passed into bpf programs is different depending on bpf program type. The verifier incorrectly marked ctx->data and ctx->data_end access based on ctx offset only. That caused loads in tracing programs int bpf_prog(struct pt_regs *ctx) { .. ctx->ax .. } to be incorrectly marked as PTR_TO_PACKET which later caused verifier to reject the program that was actually valid in tracing context. Fix this by doing program type specific matching of ctx offsets. Fixes: 969bf05eb3ce ("bpf: direct packet access") Reported-by: Sasha Goldshtein <> Signed-off-by: Alexei Starovoitov <> Acked-by: Daniel Borkmann <> Signed-off-by: David S. Miller <>
2016-06-15kernel/kcov: unproxify debugfs file's fopsNicolai Stange1-1/+6
Since commit 49d200deaa68 ("debugfs: prevent access to removed files' private data"), a debugfs file's file_operations methods get proxied through lifetime aware wrappers. However, only a certain subset of the file_operations members is supported by debugfs and ->mmap isn't among them -- it appears to be NULL from the VFS layer's perspective. This behaviour breaks the /sys/kernel/debug/kcov file introduced concurrently with commit 5c9a8750a640 ("kernel: add kcov code coverage"). Since that file never gets removed, there is no file removal race and thus, a lifetime checking proxy isn't needed. Avoid the proxying for /sys/kernel/debug/kcov by creating it via debugfs_create_file_unsafe() rather than debugfs_create_file(). Fixes: 49d200deaa68 ("debugfs: prevent access to removed files' private data") Fixes: 5c9a8750a640 ("kernel: add kcov code coverage") Reported-by: Sasha Levin <> Signed-off-by: Nicolai Stange <> Signed-off-by: Greg Kroah-Hartman <>
2016-06-14kernel/sysrq, watchdog, sched/core: Reset watchdog on all CPUs while ↵Andrey Ryabinin1-2/+4
processing sysrq-w Lengthy output of sysrq-w may take a lot of time on slow serial console. Currently we reset NMI-watchdog on the current CPU to avoid spurious lockup messages. Sometimes this doesn't work since softlockup watchdog might trigger on another CPU which is waiting for an IPI to proceed. We reset softlockup watchdogs on all CPUs, but we do this only after listing all tasks, and this may be too late on a busy system. So, reset watchdogs CPUs earlier, in for_each_process_thread() loop. Signed-off-by: Andrey Ryabinin <> Cc: Linus Torvalds <> Cc: Peter Zijlstra <> Cc: Thomas Gleixner <> Cc: <> Link: Signed-off-by: Ingo Molnar <>
2016-06-14sched/debug: Fix deadlock when enabling sched eventsJosh Poimboeuf1-1/+1
I see a hang when enabling sched events: echo 1 > /sys/kernel/debug/tracing/events/sched/enable The printk buffer shows: BUG: spinlock recursion on CPU#1, swapper/1/0 lock: 0xffff88007d5d8c00, .magic: dead4ead, .owner: swapper/1/0, .owner_cpu: 1 CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.7.0-rc2+ #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.8.1-20150318_183358- 04/01/2014 ... Call Trace: <IRQ> [<ffffffff8143d663>] dump_stack+0x85/0xc2 [<ffffffff81115948>] spin_dump+0x78/0xc0 [<ffffffff81115aea>] do_raw_spin_lock+0x11a/0x150 [<ffffffff81891471>] _raw_spin_lock+0x61/0x80 [<ffffffff810e5466>] ? try_to_wake_up+0x256/0x4e0 [<ffffffff810e5466>] try_to_wake_up+0x256/0x4e0 [<ffffffff81891a0a>] ? _raw_spin_unlock_irqrestore+0x4a/0x80 [<ffffffff810e5705>] wake_up_process+0x15/0x20 [<ffffffff810cebb4>] insert_work+0x84/0xc0 [<ffffffff810ced7f>] __queue_work+0x18f/0x660 [<ffffffff810cf9a6>] queue_work_on+0x46/0x90 [<ffffffffa00cd95b>] drm_fb_helper_dirty.isra.11+0xcb/0xe0 [drm_kms_helper] [<ffffffffa00cdac0>] drm_fb_helper_sys_imageblit+0x30/0x40 [drm_kms_helper] [<ffffffff814babcd>] soft_cursor+0x1ad/0x230 [<ffffffff814ba379>] bit_cursor+0x649/0x680 [<ffffffff814b9d30>] ? update_attr.isra.2+0x90/0x90 [<ffffffff814b5e6a>] fbcon_cursor+0x14a/0x1c0 [<ffffffff81555ef8>] hide_cursor+0x28/0x90 [<ffffffff81558b6f>] vt_console_print+0x3bf/0x3f0 [<ffffffff81122c63>] call_console_drivers.constprop.24+0x183/0x200 [<ffffffff811241f4>] console_unlock+0x3d4/0x610 [<ffffffff811247f5>] vprintk_emit+0x3c5/0x610 [<ffffffff81124bc9>] vprintk_default+0x29/0x40 [<ffffffff811e965b>] printk+0x57/0x73 [<ffffffff810f7a9e>] enqueue_entity+0xc2e/0xc70 [<ffffffff810f7b39>] enqueue_task_fair+0x59/0xab0 [<ffffffff8106dcd9>] ? kvm_sched_clock_read+0x9/0x20 [<ffffffff8103fb39>] ? sched_clock+0x9/0x10 [<ffffffff810e3fcc>] activate_task+0x5c/0xa0 [<ffffffff810e4514>] ttwu_do_activate+0x54/0xb0 [<ffffffff810e5cea>] sched_ttwu_pending+0x7a/0xb0 [<ffffffff810e5e51>] scheduler_ipi+0x61/0x170 [<ffffffff81059e7f>] smp_trace_reschedule_interrupt+0x4f/0x2a0 [<ffffffff81893ba6>] trace_reschedule_interrupt+0x96/0xa0 <EOI> [<ffffffff8106e0d6>] ? native_safe_halt+0x6/0x10 [<ffffffff8110fb1d>] ? trace_hardirqs_on+0xd/0x10 [<ffffffff81040ac0>] default_idle+0x20/0x1a0 [<ffffffff8104147f>] arch_cpu_idle+0xf/0x20 [<ffffffff81102f8f>] default_idle_call+0x2f/0x50 [<ffffffff8110332e>] cpu_startup_entry+0x37e/0x450 [<ffffffff8105af70>] start_secondary+0x160/0x1a0 Note the hang only occurs when echoing the above from a physical serial console, not from an ssh session. The bug is caused by a deadlock where the task is trying to grab the rq lock twice because printk()'s aren't safe in sched code. Signed-off-by: Josh Poimboeuf <> Cc: Linus Torvalds <> Cc: Matt Fleming <> Cc: Mel Gorman <> Cc: Mike Galbraith <> Cc: Peter Zijlstra <> Cc: Srikar Dronamraju <> Cc: Thomas Gleixner <> Cc: Fixes: cb2517653fcc ("sched/debug: Make schedstats a runtime tunable that is disabled by default") Link: Signed-off-by: Ingo Molnar <>
2016-06-14sched/fair: Fix post_init_entity_util_avg() serializationPeter Zijlstra2-3/+8
Chris Wilson reported a divide by 0 at: post_init_entity_util_avg(): > 725 if (cfs_rq->avg.util_avg != 0) { > 726 sa->util_avg = cfs_rq->avg.util_avg * se->load.weight; > -> 727 sa->util_avg /= (cfs_rq->avg.load_avg + 1); > 728 > 729 if (sa->util_avg > cap) > 730 sa->util_avg = cap; > 731 } else { Which given the lack of serialization, and the code generated from update_cfs_rq_load_avg() is entirely possible: if (atomic_long_read(&cfs_rq->removed_load_avg)) { s64 r = atomic_long_xchg(&cfs_rq->removed_load_avg, 0); sa->load_avg = max_t(long, sa->load_avg - r, 0); sa->load_sum = max_t(s64, sa->load_sum - r * LOAD_AVG_MAX, 0); removed_load = 1; } turns into: ffffffff81087064: 49 8b 85 98 00 00 00 mov 0x98(%r13),%rax ffffffff8108706b: 48 85 c0 test %rax,%rax ffffffff8108706e: 74 40 je ffffffff810870b0 ffffffff81087070: 4c 89 f8 mov %r15,%rax ffffffff81087073: 49 87 85 98 00 00 00 xchg %rax,0x98(%r13) ffffffff8108707a: 49 29 45 70 sub %rax,0x70(%r13) ffffffff8108707e: 4c 89 f9 mov %r15,%rcx ffffffff81087081: bb 01 00 00 00 mov $0x1,%ebx ffffffff81087086: 49 83 7d 70 00 cmpq $0x0,0x70(%r13) ffffffff8108708b: 49 0f 49 4d 70 cmovns 0x70(%r13),%rcx Which you'll note ends up with 'sa->load_avg - r' in memory at ffffffff8108707a. By calling post_init_entity_util_avg() under rq->lock we're sure to be fully serialized against PELT updates and cannot observe intermediate state like this. Reported-by: Chris Wilson <> Signed-off-by: Peter Zijlstra (Intel) <> Cc: Andrey Ryabinin <> Cc: Linus Torvalds <> Cc: Mike Galbraith <> Cc: Peter Zijlstra <> Cc: Thomas Gleixner <> Cc: Yuyang Du <> Cc: Cc: Cc: Cc: Fixes: 2b8c41daba32 ("sched/fair: Initiate a new task's util avg to a bounded value") Link: Signed-off-by: Ingo Molnar <>
2016-06-10Merge branch 'stacking-fixes' (vfs stacking fixes from Jann)Linus Torvalds1-1/+2
Merge filesystem stacking fixes from Jann Horn. * emailed patches from Jann Horn <>: sched: panic on corrupted stack end ecryptfs: forbid opening files without mmap handler proc: prevent stacking filesystems on top
2016-06-10sched: panic on corrupted stack endJann Horn1-1/+2
Until now, hitting this BUG_ON caused a recursive oops (because oops handling involves do_exit(), which calls into the scheduler, which in turn raises an oops), which caused stuff below the stack to be overwritten until a panic happened (e.g. via an oops in interrupt context, caused by the overwritten CPU index in the thread_info). Just panic directly. Signed-off-by: Jann Horn <> Signed-off-by: Linus Torvalds <>
2016-06-10Merge branch 'sched-urgent-for-linus' of ↵Linus Torvalds3-16/+28
git:// Pull scheduler fixes from Ingo Molnar: "Two scheduler debugging fixes" * 'sched-urgent-for-linus' of git:// sched/debug: Fix 'schedstats=enable' cmdline option sched/debug: Fix /proc/sched_debug regression
2016-06-10Merge branch 'perf-urgent-for-linus' of ↵Linus Torvalds1-4/+2
git:// Pull perf fixes from Ingo Molnar: "A handful of tooling fixes, two PMU driver fixes and a cleanup of redundant code that addresses a security analyzer false positive" * 'perf-urgent-for-linus' of git:// perf/core: Remove a redundant check perf/x86/intel/uncore: Remove SBOX support for Broadwell server perf ctf: Convert invalid chars in a string before set value perf record: Fix crash when kptr is restricted perf symbols: Check kptr_restrict for root perf/x86/intel/rapl: Fix pmus free during cleanup
2016-06-10Merge branch 'locking-urgent-for-linus' of ↵Linus Torvalds3-6/+77
git:// Pull locking fixes from Ingo Molnar: "Misc fixes: - a file-based futex fix - one more spin_unlock_wait() fix - a ww-mutex deadlock detection improvement/fix - and a raw_read_seqcount_latch() barrier fix" * 'locking-urgent-for-linus' of git:// futex: Calculate the futex key based on a tail page for file-based futexes locking/qspinlock: Fix spin_unlock_wait() some more locking/ww_mutex: Report recursive ww_mutex locking early locking/seqcount: Re-fix raw_read_seqcount_latch()
2016-06-10Merge git:// Torvalds1-2/+2
Pull networking fixes from David Miller: 1) nfnetlink timestamp taken from wrong skb, fix from Florian Westphal. 2) Revert some msleep conversions in rtlwifi as these spots are in atomic context, from Larry Finger. 3) Validate that NFTA_SET_TABLE attribute is actually specified when we call nf_tables_getset(). From Phil Turnbull. 4) Don't do mdio_reset in stmmac driver with spinlock held as that can sleep, from Vincent Palatin. 5) sk_filter() does things other than run a BPF filter, so we should not elide it's call just because sk->sk_filter is NULL. Fix from Eric Dumazet. 6) Fix missing backlog updates in several packet schedulers, from Cong Wang. 7) bnx2x driver should allow VLAN add/remove while the interface is down, from Michal Schmidt. 8) Several RDS/TCP race fixes from Sowmini Varadhan. 9) fq_codel scheduler doesn't return correct queue length in dumps, from Eric Dumazet. 10) Fix TCP stats for tail loss probe and early retransmit in ipv6, from Yuchung Cheng. 11) Properly initialize udp_tunnel_socket_cfg in l2tp_tunnel_create(), from Guillaume Nault. 12) qfq scheduler leaks SKBs if a kzalloc fails, fix from Florian Westphal. 13) sock_fprog passed into PACKET_FANOUT_DATA needs compat handling, from Willem de Bruijn. * git:// (85 commits) vmxnet3: segCnt can be 1 for LRO packets packet: compat support for sock_fprog stmmac: fix parameter to dwmac4_set_umac_addr() net/mlx5e: Fix blue flame quota logic net/mlx5e: Use ndo_stop explicitly at shutdown flow net/mlx5: E-Switch, always set mc_promisc for allmulti vports net/mlx5: E-Switch, Modify node guid on vf set MAC net/mlx5: E-Switch, Fix vport enable flow net/mlx5: E-Switch, Use the correct error check on returned pointers net/mlx5: E-Switch, Use the correct free() function net/mlx5: Fix E-Switch flow steering capabilities check net/mlx5: Fix flow steering NIC capabilities check net/mlx5: Fix root flow table update net/mlx5: Fix MLX5_CMD_OP_MAX to be defined correctly net/mlx5: Fix masking of reserved bits in XRCD number net/mlx5: Fix the size of modify QP mailbox mlxsw: spectrum: Don't sleep during ndo_get_phys_port_name() mlxsw: spectrum: Make split flow match firmware requirements wext: Fix 32 bit iwpriv compatibility issue with 64 bit Kernel cfg80211: remove get/set antenna and tx power warnings ...
2016-06-10Merge tag 'pm-4.7-rc3' of ↵Linus Torvalds1-1/+1
git:// Pull power management fixes from Rafael Wysocki: "Stable-candidate fixes for the intel_pstate driver and the cpuidle core. Specifics: - Fix two intel_pstate initialization issues, one of which was introduced during the 4.4 cycle (Srinivas Pandruvada) - Fix kernel build with CONFIG_UBSAN set and CONFIG_CPU_IDLE unset (Catalin Marinas)" * tag 'pm-4.7-rc3' of git:// cpufreq: intel_pstate: Fix ->set_policy() interface for no_turbo cpufreq: intel_pstate: Fix code ordering in intel_pstate_set_policy() cpuidle: Do not access cpuidle_devices when !CONFIG_CPU_IDLE
2016-06-09Merge branches 'pm-cpufreq-fixes' and 'pm-cpuidle'Rafael J. Wysocki1-1/+1
* pm-cpufreq-fixes: cpufreq: intel_pstate: Fix ->set_policy() interface for no_turbo cpufreq: intel_pstate: Fix code ordering in intel_pstate_set_policy() * pm-cpuidle: cpuidle: Do not access cpuidle_devices when !CONFIG_CPU_IDLE
2016-06-09kernel/relay.c: fix potential memory leakZhouyi Zhou1-0/+1
When relay_open_buf() fails in relay_open(), code will goto free_bufs, but chan is nowhere freed. Link: Signed-off-by: Zhouyi Zhou <> Cc: Jens Axboe <> Cc: Al Viro <> Signed-off-by: Andrew Morton <> Signed-off-by: Linus Torvalds <>
2016-06-08futex: Calculate the futex key based on a tail page for file-based futexesMel Gorman1-3/+11
Mike Galbraith reported that the LTP test case futex_wake04 was broken by commit 65d8fc777f6d ("futex: Remove requirement for lock_page() in get_futex_key()"). This test case uses futexes backed by hugetlbfs pages and so there is an associated inode with a futex stored on such pages. The problem is that the key is being calculated based on the head page index of the hugetlbfs page and not the tail page. Prior to the optimisation, the page lock was used to stabilise mappings and pin the inode is file-backed which is overkill. If the page was a compound page, the head page was automatically looked up as part of the page lock operation but the tail page index was used to calculate the futex key. After the optimisation, the compound head is looked up early and the page lock is only relied upon to identify truncated pages, special pages or a shmem page moving to swapcache. The head page is looked up because without the page lock, special care has to be taken to pin the inode correctly. However, the tail page is still required to calculate the futex key so this patch records the tail page. On vanilla 4.6, the output of the test case is; futex_wake04 0 TINFO : Hugepagesize 2097152 futex_wake04 1 TFAIL : futex_wake04.c:126: Bug: wait_thread2 did not wake after 30 secs. With the patch applied futex_wake04 0 TINFO : Hugepagesize 2097152 futex_wake04 1 TPASS : Hi hydra, thread2 awake! Fixes: 65d8fc777f6d "futex: Remove requirement for lock_page() in get_futex_key()" Reported-and-tested-by: Mike Galbraith <> Signed-off-by: Mel Gorman <> Acked-by: Peter Zijlstra (Intel) <> Reviewed-by: Davidlohr Bueso <> Cc: Sebastian Andrzej Siewior <> Cc: Link: Signed-off-by: Thomas Gleixner <>
2016-06-08sched/debug: Fix 'schedstats=enable' cmdline optionJosh Poimboeuf1-5/+21
The 'schedstats=enable' option doesn't work, and also produces the following warning during boot: WARNING: CPU: 0 PID: 0 at /home/jpoimboe/git/linux/kernel/jump_label.c:61 static_key_slow_inc+0x8c/0xa0 static_key_slow_inc used before call to jump_label_init Modules linked in: CPU: 0 PID: 0 Comm: swapper Not tainted 4.7.0-rc1+ #25 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.8.1-20150318_183358- 04/01/2014 0000000000000086 3ae3475a4bea95d4 ffffffff81e03da8 ffffffff8143fc83 ffffffff81e03df8 0000000000000000 ffffffff81e03de8 ffffffff810b1ffb 0000003d00000096 ffffffff823514d0 ffff88007ff197c8 0000000000000000 Call Trace: [<ffffffff8143fc83>] dump_stack+0x85/0xc2 [<ffffffff810b1ffb>] __warn+0xcb/0xf0 [<ffffffff810b207f>] warn_slowpath_fmt+0x5f/0x80 [<ffffffff811e9c0c>] static_key_slow_inc+0x8c/0xa0 [<ffffffff810e07c6>] static_key_enable+0x16/0x40 [<ffffffff8216d633>] setup_schedstats+0x29/0x94 [<ffffffff82148a05>] unknown_bootoption+0x89/0x191 [<ffffffff810d8617>] parse_args+0x297/0x4b0 [<ffffffff82148d61>] start_kernel+0x1d8/0x4a9 [<ffffffff8214897c>] ? set_init_arg+0x55/0x55 [<ffffffff82148120>] ? early_idt_handler_array+0x120/0x120 [<ffffffff821482db>] x86_64_start_reservations+0x2f/0x31 [<ffffffff82148427>] x86_64_start_kernel+0x14a/0x16d The problem is that it tries to update the 'sched_schedstats' static key before jump labels have been initialized. Changing jump_label_init() to be called earlier before parse_early_param() wouldn't fix it: it would still fail trying to poke_text() because mm isn't yet initialized. Instead, just create a temporary '__sched_schedstats' variable which can be copied to the static key later during sched_init() after jump labels have been initialized. Signed-off-by: Josh Poimboeuf <> Signed-off-by: Peter Zijlstra (Intel) <> Cc: Linus Torvalds <> Cc: Matt Fleming <> Cc: Mel Gorman <> Cc: Peter Zijlstra <> Cc: Srikar Dronamraju <> Cc: Thomas Gleixner <> Fixes: cb2517653fcc ("sched/debug: Make schedstats a runtime tunable that is disabled by default") Link: Signed-off-by: Ingo Molnar <>
2016-06-08sched/debug: Fix /proc/sched_debug regressionJosh Poimboeuf2-11/+7
Commit: cb2517653fcc ("sched/debug: Make schedstats a runtime tunable that is disabled by default") ... introduced a bug when CONFIG_SCHEDSTATS is enabled and the runtime tunable is disabled (which is the default). The wait-time, sum-exec, and sum-sleep fields are missing from the /proc/sched_debug file in the runnable_tasks section. Fix it with a new schedstat_val() macro which returns the field value when schedstats is enabled and zero otherwise. The macro works with both SCHEDSTATS and !SCHEDSTATS. I put the macro in stats.h since it might end up being useful in other places. Signed-off-by: Josh Poimboeuf <> Signed-off-by: Peter Zijlstra (Intel) <> Acked-by: Mel Gorman <> Cc: Linus Torvalds <> Cc: Matt Fleming <> Cc: Peter Zijlstra <> Cc: Srikar Dronamraju <> Cc: Thomas Gleixner <> Fixes: cb2517653fcc ("sched/debug: Make schedstats a runtime tunable that is disabled by default") Link: Signed-off-by: Ingo Molnar <>
2016-06-08perf/core: Remove a redundant checkAlexander Shishkin1-4/+2
There is no way to end up in _free_event() with event::pmu being NULL. The latter is initialized in event allocation path and remains set forever. In case of allocation failure, the error path doesn't use _free_event(). Having the check, however, suggests that it is possible to have a event::pmu==NULL situation in _free_event() and confuses the robots. This patch gets rid of the check. Reported-by: Dan Carpenter <> Signed-off-by: Alexander Shishkin <> Signed-off-by: Peter Zijlstra (Intel) <> Cc: Arnaldo Carvalho de Melo <> Cc: Linus Torvalds <> Cc: Peter Zijlstra <> Cc: Thomas Gleixner <> Cc: Cc: Link: Signed-off-by: Ingo Molnar <>
2016-06-08locking/qspinlock: Fix spin_unlock_wait() some morePeter Zijlstra1-0/+60
While this prior commit: 54cf809b9512 ("locking,qspinlock: Fix spin_is_locked() and spin_unlock_wait()") ... fixes spin_is_locked() and spin_unlock_wait() for the usage in ipc/sem and netfilter, it does not in fact work right for the usage in task_work and futex. So while the 2 locks crossed problem: spin_lock(A) spin_lock(B) if (!spin_is_locked(B)) spin_unlock_wait(A) foo() foo(); ... works with the smp_mb() injected by both spin_is_locked() and spin_unlock_wait(), this is not sufficient for: flag = 1; smp_mb(); spin_lock() spin_unlock_wait() if (!flag) // add to lockless list // iterate lockless list ... because in this scenario, the store from spin_lock() can be delayed past the load of flag, uncrossing the variables and loosing the guarantee. This patch reworks spin_is_locked() and spin_unlock_wait() to work in both cases by exploiting the observation that while the lock byte store can be delayed, the contender must have registered itself visibly in other state contained in the word. It also allows for architectures to override both functions, as PPC and ARM64 have an additional issue for which we currently have no generic solution. Signed-off-by: Peter Zijlstra (Intel) <> Cc: Andrew Morton <> Cc: Boqun Feng <> Cc: Davidlohr Bueso <> Cc: Giovanni Gherdovich <> Cc: Linus Torvalds <> Cc: Pan Xinhui <> Cc: Paul E. McKenney <> Cc: Peter Zijlstra <> Cc: Thomas Gleixner <> Cc: Waiman Long <> Cc: Will Deacon <> Cc: # v4.2 and later Fixes: 54cf809b9512 ("locking,qspinlock: Fix spin_is_locked() and spin_unlock_wait()") Signed-off-by: Ingo Molnar <>
2016-06-07bpf, trace: use READ_ONCE for retrieving file ptrDaniel Borkmann1-2/+2
In bpf_perf_event_read() and bpf_perf_event_output(), we must use READ_ONCE() for fetching the struct file pointer, which could get updated concurrently, so we must prevent the compiler from potential refetching. We already do this with tail calls for fetching the related bpf_prog, but not so on stored perf events. Semantics for both are the same with regards to updates. Fixes: a43eec304259 ("bpf: introduce bpf_perf_event_output() helper") Fixes: 35578d798400 ("bpf: Implement function bpf_perf_event_read() that get the selected hardware PMU conuter") Signed-off-by: Daniel Borkmann <> Acked-by: Alexei Starovoitov <> Signed-off-by: David S. Miller <>
2016-06-03Merge branch 'irq-urgent-for-linus' of ↵Linus Torvalds1-1/+1
git:// Pull irq fixes from Thomas Gleixner: - a few simple fixes for fallout from the recent gic-v3 changes - a workaround for a Cavium thunderX erratum - a bugfix for the pic32 irqchip to make external interrupts work proper - a missing return value in the generic IPI management code * 'irq-urgent-for-linus' of git:// irqchip/irq-pic32-evic: Fix bug with external interrupts. irqchip/gicv3-its: numa: Enable workaround for Cavium thunderx erratum 23144 irqchip/gic-v3: Fix quiescence check in gic_enable_redist irqchip/gic-v3: Fix copy+paste mistakes in defines irqchip/gic-v3: Fix ICC_SGI1R_EL1.INTID decoding mask genirq: Fix missing return value in irq_destroy_ipi()
2016-06-03Merge tag 'irqchip-4.7-rc1' of ↵Thomas Gleixner66-1058/+6095
git:// into irq/urgent Merge irqchip updates from Marc Zyngier: - A number of embarassing buglets (GICv3, PIC32) - A more substential errata workaround for Cavium's GICv3 ITS (kept for post-rc1 due to its dependency on NUMA)
2016-06-03locking/ww_mutex: Report recursive ww_mutex locking earlyChris Wilson1-3/+6
Recursive locking for ww_mutexes was originally conceived as an exception. However, it is heavily used by the DRM atomic modesetting code. Currently, the recursive deadlock is checked after we have queued up for a busy-spin and as we never release the lock, we spin until kicked, whereupon the deadlock is discovered and reported. A simple solution for the now common problem is to move the recursive deadlock discovery to the first action when taking the ww_mutex. Suggested-by: Maarten Lankhorst <> Signed-off-by: Chris Wilson <> Signed-off-by: Peter Zijlstra (Intel) <> Reviewed-by: Maarten Lankhorst <> Cc: Andrew Morton <> Cc: Linus Torvalds <> Cc: Paul E. McKenney <> Cc: Peter Zijlstra <> Cc: Thomas Gleixner <> Cc: Link: Signed-off-by: Ingo Molnar <>
2016-06-02cpuidle: Do not access cpuidle_devices when !CONFIG_CPU_IDLECatalin Marinas1-1/+1
The cpuidle_devices per-CPU variable is only defined when CPU_IDLE is enabled. Commit c8cc7d4de7a4 ("sched/idle: Reorganize the idle loop") removed the #ifdef CONFIG_CPU_IDLE around cpuidle_idle_call() with the compiler optimising away __this_cpu_read(cpuidle_devices). However, with CONFIG_UBSAN && !CONFIG_CPU_IDLE, this optimisation no longer happens and the kernel fails to link since cpuidle_devices is not defined. This patch introduces an accessor function for the current CPU cpuidle device (returning NULL when !CONFIG_CPU_IDLE) and uses it in cpuidle_idle_call(). Signed-off-by: Catalin Marinas <> Cc: 4.5+ <> # 4.5+ Signed-off-by: Rafael J. Wysocki <>
2016-05-31Merge git:// Torvalds2-1/+1
Pull networking fixes from David Miller: 1) Fix negative error code usage in ATM layer, from Stefan Hajnoczi. 2) If CONFIG_SYSCTL is disabled, the default TTL is not initialized properly. From Ezequiel Garcia. 3) Missing spinlock init in mvneta driver, from Gregory CLEMENT. 4) Missing unlocks in hwmb error paths, also from Gregory CLEMENT. 5) Fix deadlock on team->lock when propagating features, from Ivan Vecera. 6) Work around buffer offset hw bug in alx chips, from Feng Tang. 7) Fix double listing of SCTP entries in sctp_diag dumps, from Xin Long. 8) Various statistics bug fixes in mlx4 from Eric Dumazet. 9) Fix some randconfig build errors wrt fou ipv6 from Arnd Bergmann. 10) All of l2tp was namespace aware, but the ipv6 support code was not doing so. From Shmulik Ladkani. 11) Handle on-stack hrtimers properly in pktgen, from Guenter Roeck. 12) Propagate MAC changes properly through VLAN devices, from Mike Manning. 13) Fix memory leak in bnx2x_init_one(), from Vitaly Kuznetsov. * git:// (62 commits) sfc: Track RPS flow IDs per channel instead of per function usbnet: smsc95xx: fix link detection for disabled autonegotiation virtio_net: fix virtnet_open and virtnet_probe competing for try_fill_recv bnx2x: avoid leaking memory on bnx2x_init_one() failures fou: fix IPv6 Kconfig options openvswitch: update checksum in {push,pop}_mpls sctp: sctp_diag should dump sctp socket type net: fec: update dirty_tx even if no skb vlan: Propagate MAC address to VLANs atm: iphase: off by one in rx_pkt() atm: firestream: add more reserved strings vxlan: Accept user specified MTU value when create new vxlan link net: pktgen: Call destroy_hrtimer_on_stack() timer: Export destroy_hrtimer_on_stack() net: l2tp: Make l2tp_ip6 namespace aware Documentation: ip-sysctl.txt: clarify secure_redirects sfc: use flow dissector helpers for aRFS ieee802154: fix logic error in ieee802154_llsec_parse_dev_addr net: nps_enet: Disable interrupts before napi reschedule net/lapb: tuse %*ph to dump buffers ...
2016-05-31timer: Export destroy_hrtimer_on_stack()Guenter Roeck1-0/+1
hrtimer_init_on_stack() needs a matching call to destroy_hrtimer_on_stack(), so both need to be exported. Signed-off-by: Guenter Roeck <> Signed-off-by: David S. Miller <>
2016-05-27Merge branch 'for-linus' of ↵Linus Torvalds1-0/+16
git:// Pull vfs fixes from Al Viro: "Followups to the parallel lookup work: - update docs - restore killability of the places that used to take ->i_mutex killably now that we have down_write_killable() merged - Additionally, it turns out that I missed a prerequisite for security_d_instantiate() stuff - ->getxattr() wasn't the only thing that could be called before dentry is attached to inode; with smack we needed the same treatment applied to ->setxattr() as well" * 'for-linus' of git:// switch ->setxattr() to passing dentry and inode separately switch xattr_handler->set() to passing dentry and inode separately restore killability of old mutex_lock_killable(&inode->i_mutex) users add down_write_killable_nested() update D/f/directory-locking