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2017-04-10padata: free correct variableJason A. Donenfeld1-1/+1
The author meant to free the variable that was just allocated, instead of the one that failed to be allocated, but made a simple typo. This patch rectifies that. Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Cc: stable@vger.kernel.org Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2017-04-05Merge git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6Herbert Xu1-2/+3
Merge the crypto tree to resolve conflict between caam changes.
2017-03-24padata: avoid race in reorderingJason A. Donenfeld1-2/+3
Under extremely heavy uses of padata, crashes occur, and with list debugging turned on, this happens instead: [87487.298728] WARNING: CPU: 1 PID: 882 at lib/list_debug.c:33 __list_add+0xae/0x130 [87487.301868] list_add corruption. prev->next should be next (ffffb17abfc043d0), but was ffff8dba70872c80. (prev=ffff8dba70872b00). [87487.339011] [<ffffffff9a53d075>] dump_stack+0x68/0xa3 [87487.342198] [<ffffffff99e119a1>] ? console_unlock+0x281/0x6d0 [87487.345364] [<ffffffff99d6b91f>] __warn+0xff/0x140 [87487.348513] [<ffffffff99d6b9aa>] warn_slowpath_fmt+0x4a/0x50 [87487.351659] [<ffffffff9a58b5de>] __list_add+0xae/0x130 [87487.354772] [<ffffffff9add5094>] ? _raw_spin_lock+0x64/0x70 [87487.357915] [<ffffffff99eefd66>] padata_reorder+0x1e6/0x420 [87487.361084] [<ffffffff99ef0055>] padata_do_serial+0xa5/0x120 padata_reorder calls list_add_tail with the list to which its adding locked, which seems correct: spin_lock(&squeue->serial.lock); list_add_tail(&padata->list, &squeue->serial.list); spin_unlock(&squeue->serial.lock); This therefore leaves only place where such inconsistency could occur: if padata->list is added at the same time on two different threads. This pdata pointer comes from the function call to padata_get_next(pd), which has in it the following block: next_queue = per_cpu_ptr(pd->pqueue, cpu); padata = NULL; reorder = &next_queue->reorder; if (!list_empty(&reorder->list)) { padata = list_entry(reorder->list.next, struct padata_priv, list); spin_lock(&reorder->lock); list_del_init(&padata->list); atomic_dec(&pd->reorder_objects); spin_unlock(&reorder->lock); pd->processed++; goto out; } out: return padata; I strongly suspect that the problem here is that two threads can race on reorder list. Even though the deletion is locked, call to list_entry is not locked, which means it's feasible that two threads pick up the same padata object and subsequently call list_add_tail on them at the same time. The fix is thus be hoist that lock outside of that block. Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Acked-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2017-03-18Merge branch 'smp-urgent-for-linus' of ↵Linus Torvalds1-14/+14
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull CPU hotplug fix from Thomas Gleixner: "A single fix preventing the concurrent execution of the CPU hotplug callback install/invocation machinery. Long standing bug caused by a massive brain slip of that Gleixner dude, which went unnoticed for almost a year" * 'smp-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: cpu/hotplug: Serialize callback invocations proper
2017-03-17Merge branch 'perf-urgent-for-linus' of ↵Linus Torvalds1-16/+48
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf fixes from Thomas Gleixner: "A set of perf related fixes: - fix a CR4.PCE propagation issue caused by usage of mm instead of active_mm and therefore propagated the wrong value. - perf core fixes, which plug a use-after-free issue and make the event inheritance on fork more robust. - a tooling fix for symbol handling" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf symbols: Fix symbols__fixup_end heuristic for corner cases x86/perf: Clarify why x86_pmu_event_mapped() isn't racy x86/perf: Fix CR4.PCE propagation to use active_mm instead of mm perf/core: Better explain the inherit magic perf/core: Simplify perf_event_free_task() perf/core: Fix event inheritance on fork() perf/core: Fix use-after-free in perf_release()
2017-03-17Merge branch 'sched-urgent-for-linus' of ↵Linus Torvalds2-14/+69
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler fixes from Thomas Gleixner: "From the scheduler departement: - a bunch of sched deadline related fixes which deal with various buglets and corner cases. - two fixes for the loadavg spikes which are caused by the delayed NOHZ accounting" * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/deadline: Use deadline instead of period when calculating overflow sched/deadline: Throttle a constrained deadline task activated after the deadline sched/deadline: Make sure the replenishment timer fires in the next period sched/loadavg: Use {READ,WRITE}_ONCE() for sample window sched/loadavg: Avoid loadavg spikes caused by delayed NO_HZ accounting sched/deadline: Add missing update_rq_clock() in dl_task_timer()
2017-03-17Merge branch 'locking-urgent-for-linus' of ↵Linus Torvalds2-14/+24
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull locking fixes from Thomas Gleixner: "Three fixes related to locking: - fix a SIGKILL issue for RWSEM_GENERIC_SPINLOCK which has been fixed for the XCHGADD variant already - plug a potential use after free in the futex code - prevent leaking a held spinlock in an futex error handling code path" * 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: locking/rwsem: Fix down_write_killable() for CONFIG_RWSEM_GENERIC_SPINLOCK=y futex: Add missing error handling to FUTEX_REQUEUE_PI futex: Fix potential use-after-free in FUTEX_REQUEUE_PI
2017-03-17mm: add private lock to serialize memory hotplug operationsHeiko Carstens1-4/+0
Commit bfc8c90139eb ("mem-hotplug: implement get/put_online_mems") introduced new functions get/put_online_mems() and mem_hotplug_begin/end() in order to allow similar semantics for memory hotplug like for cpu hotplug. The corresponding functions for cpu hotplug are get/put_online_cpus() and cpu_hotplug_begin/done() for cpu hotplug. The commit however missed to introduce functions that would serialize memory hotplug operations like they are done for cpu hotplug with cpu_maps_update_begin/done(). This basically leaves mem_hotplug.active_writer unprotected and allows concurrent writers to modify it, which may lead to problems as outlined by commit f931ab479dd2 ("mm: fix devm_memremap_pages crash, use mem_hotplug_{begin, done}"). That commit was extended again with commit b5d24fda9c3d ("mm, devm_memremap_pages: hold device_hotplug lock over mem_hotplug_{begin, done}") which serializes memory hotplug operations for some call sites by using the device_hotplug lock. In addition with commit 3fc21924100b ("mm: validate device_hotplug is held for memory hotplug") a sanity check was added to mem_hotplug_begin() to verify that the device_hotplug lock is held. This in turn triggers the following warning on s390: WARNING: CPU: 6 PID: 1 at drivers/base/core.c:643 assert_held_device_hotplug+0x4a/0x58 Call Trace: assert_held_device_hotplug+0x40/0x58) mem_hotplug_begin+0x34/0xc8 add_memory_resource+0x7e/0x1f8 add_memory+0xda/0x130 add_memory_merged+0x15c/0x178 sclp_detect_standby_memory+0x2ae/0x2f8 do_one_initcall+0xa2/0x150 kernel_init_freeable+0x228/0x2d8 kernel_init+0x2a/0x140 kernel_thread_starter+0x6/0xc One possible fix would be to add more lock_device_hotplug() and unlock_device_hotplug() calls around each call site of mem_hotplug_begin/end(). But that would give the device_hotplug lock additional semantics it better should not have (serialize memory hotplug operations). Instead add a new memory_add_remove_lock which has the similar semantics like cpu_add_remove_lock for cpu hotplug. To keep things hopefully a bit easier the lock will be locked and unlocked within the mem_hotplug_begin/end() functions. Link: http://lkml.kernel.org/r/20170314125226.16779-2-heiko.carstens@de.ibm.com Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Reported-by: Sebastian Ott <sebott@linux.vnet.ibm.com> Acked-by: Dan Williams <dan.j.williams@intel.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Ben Hutchings <ben@decadent.org.uk> Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-03-16perf/core: Better explain the inherit magicPeter Zijlstra1-3/+33
While going through the event inheritance code Oleg got confused. Add some comments to better explain the silent dissapearance of orphaned events. So what happens is that at perf_event_release_kernel() time; when an event looses its connection to userspace (and ceases to exist from the user's perspective) we can still have an arbitrary amount of inherited copies of the event. We want to synchronously find and remove all these child events. Since that requires a bit of lock juggling, there is the possibility that concurrent clone()s will create new child events. Therefore we first mark the parent event as DEAD, which marks all the extant child events as orphaned. We then avoid copying orphaned events; in order to avoid getting more of them. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Oleg Nesterov <oleg@redhat.com> 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> Cc: fweisbec@gmail.com Link: http://lkml.kernel.org/r/20170316125823.289567442@infradead.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-16perf/core: Simplify perf_event_free_task()Peter Zijlstra1-11/+1
We have ctx->event_list that contains all events; no need to repeatedly iterate the group lists to find them all. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Oleg Nesterov <oleg@redhat.com> 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> Cc: fweisbec@gmail.com Link: http://lkml.kernel.org/r/20170316125823.239678244@infradead.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-16perf/core: Fix event inheritance on fork()Peter Zijlstra1-2/+3
While hunting for clues to a use-after-free, Oleg spotted that perf_event_init_context() can loose an error value with the result that fork() can succeed even though we did not fully inherit the perf event context. Spotted-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> 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> Cc: oleg@redhat.com Cc: stable@vger.kernel.org Fixes: 889ff0150661 ("perf/core: Split context's event group list into pinned and non-pinned lists") Link: http://lkml.kernel.org/r/20170316125823.190342547@infradead.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-16perf/core: Fix use-after-free in perf_release()Peter Zijlstra1-0/+11
Dmitry reported syzcaller tripped a use-after-free in perf_release(). After much puzzlement Oleg spotted the below scenario: Task1 Task2 fork() perf_event_init_task() /* ... */ goto bad_fork_$foo; /* ... */ perf_event_free_task() mutex_lock(ctx->lock) perf_free_event(B) perf_event_release_kernel(A) mutex_lock(A->child_mutex) list_for_each_entry(child, ...) { /* child == B */ ctx = B->ctx; get_ctx(ctx); mutex_unlock(A->child_mutex); mutex_lock(A->child_mutex) list_del_init(B->child_list) mutex_unlock(A->child_mutex) /* ... */ mutex_unlock(ctx->lock); put_ctx() /* >0 */ free_task(); mutex_lock(ctx->lock); mutex_lock(A->child_mutex); /* ... */ mutex_unlock(A->child_mutex); mutex_unlock(ctx->lock) put_ctx() /* 0 */ ctx->task && !TOMBSTONE put_task_struct() /* UAF */ This patch closes the hole by making perf_event_free_task() destroy the task <-> ctx relation such that perf_event_release_kernel() will no longer observe the now dead task. Spotted-by: Oleg Nesterov <oleg@redhat.com> Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> 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> Cc: fweisbec@gmail.com Cc: oleg@redhat.com Cc: stable@vger.kernel.org Fixes: c6e5b73242d2 ("perf: Synchronously clean up child events") Link: http://lkml.kernel.org/r/20170314155949.GE32474@worktop Link: http://lkml.kernel.org/r/20170316125823.140295131@infradead.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-16sched/deadline: Use deadline instead of period when calculating overflowSteven Rostedt (VMware)1-4/+4
I was testing Daniel's changes with his test case, and tweaked it a little. Instead of having the runtime equal to the deadline, I increased the deadline ten fold. Daniel's test case had: attr.sched_runtime = 2 * 1000 * 1000; /* 2 ms */ attr.sched_deadline = 2 * 1000 * 1000; /* 2 ms */ attr.sched_period = 2 * 1000 * 1000 * 1000; /* 2 s */ To make it more interesting, I changed it to: attr.sched_runtime = 2 * 1000 * 1000; /* 2 ms */ attr.sched_deadline = 20 * 1000 * 1000; /* 20 ms */ attr.sched_period = 2 * 1000 * 1000 * 1000; /* 2 s */ The results were rather surprising. The behavior that Daniel's patch was fixing came back. The task started using much more than .1% of the CPU. More like 20%. Looking into this I found that it was due to the dl_entity_overflow() constantly returning true. That's because it uses the relative period against relative runtime vs the absolute deadline against absolute runtime. runtime / (deadline - t) > dl_runtime / dl_period There's even a comment mentioning this, and saying that when relative deadline equals relative period, that the equation is the same as using deadline instead of period. That comment is backwards! What we really want is: runtime / (deadline - t) > dl_runtime / dl_deadline We care about if the runtime can make its deadline, not its period. And then we can say "when the deadline equals the period, the equation is the same as using dl_period instead of dl_deadline". After correcting this, now when the task gets enqueued, it can throttle correctly, and Daniel's fix to the throttling of sleeping deadline tasks works even when the runtime and deadline are not the same. Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Daniel Bristot de Oliveira <bristot@redhat.com> Cc: Juri Lelli <juri.lelli@arm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Luca Abeni <luca.abeni@santannapisa.it> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Romulo Silva de Oliveira <romulo.deoliveira@ufsc.br> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tommaso Cucinotta <tommaso.cucinotta@sssup.it> Link: http://lkml.kernel.org/r/02135a27f1ae3fe5fd032568a5a2f370e190e8d7.1488392936.git.bristot@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-16sched/deadline: Throttle a constrained deadline task activated after the ↵Daniel Bristot de Oliveira1-0/+45
deadline During the activation, CBS checks if it can reuse the current task's runtime and period. If the deadline of the task is in the past, CBS cannot use the runtime, and so it replenishes the task. This rule works fine for implicit deadline tasks (deadline == period), and the CBS was designed for implicit deadline tasks. However, a task with constrained deadline (deadine < period) might be awakened after the deadline, but before the next period. In this case, replenishing the task would allow it to run for runtime / deadline. As in this case deadline < period, CBS enables a task to run for more than the runtime / period. In a very loaded system, this can cause a domino effect, making other tasks miss their deadlines. To avoid this problem, in the activation of a constrained deadline task after the deadline but before the next period, throttle the task and set the replenishing timer to the begin of the next period, unless it is boosted. Reproducer: --------------- %< --------------- int main (int argc, char **argv) { int ret; int flags = 0; unsigned long l = 0; struct timespec ts; struct sched_attr attr; memset(&attr, 0, sizeof(attr)); attr.size = sizeof(attr); attr.sched_policy = SCHED_DEADLINE; attr.sched_runtime = 2 * 1000 * 1000; /* 2 ms */ attr.sched_deadline = 2 * 1000 * 1000; /* 2 ms */ attr.sched_period = 2 * 1000 * 1000 * 1000; /* 2 s */ ts.tv_sec = 0; ts.tv_nsec = 2000 * 1000; /* 2 ms */ ret = sched_setattr(0, &attr, flags); if (ret < 0) { perror("sched_setattr"); exit(-1); } for(;;) { /* XXX: you may need to adjust the loop */ for (l = 0; l < 150000; l++); /* * The ideia is to go to sleep right before the deadline * and then wake up before the next period to receive * a new replenishment. */ nanosleep(&ts, NULL); } exit(0); } --------------- >% --------------- On my box, this reproducer uses almost 50% of the CPU time, which is obviously wrong for a task with 2/2000 reservation. Signed-off-by: Daniel Bristot de Oliveira <bristot@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Juri Lelli <juri.lelli@arm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Luca Abeni <luca.abeni@santannapisa.it> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Romulo Silva de Oliveira <romulo.deoliveira@ufsc.br> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tommaso Cucinotta <tommaso.cucinotta@sssup.it> Link: http://lkml.kernel.org/r/edf58354e01db46bf42df8d2dd32418833f68c89.1488392936.git.bristot@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-16sched/deadline: Make sure the replenishment timer fires in the next periodDaniel Bristot de Oliveira1-2/+7
Currently, the replenishment timer is set to fire at the deadline of a task. Although that works for implicit deadline tasks because the deadline is equals to the begin of the next period, that is not correct for constrained deadline tasks (deadline < period). For instance: f.c: --------------- %< --------------- int main (void) { for(;;); } --------------- >% --------------- # gcc -o f f.c # trace-cmd record -e sched:sched_switch \ -e syscalls:sys_exit_sched_setattr \ chrt -d --sched-runtime 490000000 \ --sched-deadline 500000000 \ --sched-period 1000000000 0 ./f # trace-cmd report | grep "{pid of ./f}" After setting parameters, the task is replenished and continue running until being throttled: f-11295 [003] 13322.113776: sys_exit_sched_setattr: 0x0 The task is throttled after running 492318 ms, as expected: f-11295 [003] 13322.606094: sched_switch: f:11295 [-1] R ==> watchdog/3:32 [0] But then, the task is replenished 500719 ms after the first replenishment: <idle>-0 [003] 13322.614495: sched_switch: swapper/3:0 [120] R ==> f:11295 [-1] Running for 490277 ms: f-11295 [003] 13323.104772: sched_switch: f:11295 [-1] R ==> swapper/3:0 [120] Hence, in the first period, the task runs 2 * runtime, and that is a bug. During the first replenishment, the next deadline is set one period away. So the runtime / period starts to be respected. However, as the second replenishment took place in the wrong instant, the next replenishment will also be held in a wrong instant of time. Rather than occurring in the nth period away from the first activation, it is taking place in the (nth period - relative deadline). Signed-off-by: Daniel Bristot de Oliveira <bristot@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Luca Abeni <luca.abeni@santannapisa.it> Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Reviewed-by: Juri Lelli <juri.lelli@arm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Romulo Silva de Oliveira <romulo.deoliveira@ufsc.br> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tommaso Cucinotta <tommaso.cucinotta@sssup.it> Link: http://lkml.kernel.org/r/ac50d89887c25285b47465638354b63362f8adff.1488392936.git.bristot@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-16locking/rwsem: Fix down_write_killable() for CONFIG_RWSEM_GENERIC_SPINLOCK=yNiklas Cassel1-5/+11
We hang if SIGKILL has been sent, but the task is stuck in down_read() (after do_exit()), even though no task is doing down_write() on the rwsem in question: INFO: task libupnp:21868 blocked for more than 120 seconds. libupnp D 0 21868 1 0x08100008 ... Call Trace: __schedule() schedule() __down_read() do_exit() do_group_exit() __wake_up_parent() This bug has already been fixed for CONFIG_RWSEM_XCHGADD_ALGORITHM=y in the following commit: 04cafed7fc19 ("locking/rwsem: Fix down_write_killable()") ... however, this bug also exists for CONFIG_RWSEM_GENERIC_SPINLOCK=y. Signed-off-by: Niklas Cassel <niklas.cassel@axis.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: <mhocko@suse.com> Cc: <stable@vger.kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Niklas Cassel <niklass@axis.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: d47996082f52 ("locking/rwsem: Introduce basis for down_write_killable()") Link: http://lkml.kernel.org/r/1487981873-12649-1-git-send-email-niklass@axis.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-16sched/loadavg: Use {READ,WRITE}_ONCE() for sample windowMatt Fleming1-7/+11
'calc_load_update' is accessed without any kind of locking and there's a clear assumption in the code that only a single value is read or written. Make this explicit by using READ_ONCE() and WRITE_ONCE(), and avoid unintentionally seeing multiple values, or having the load/stores split. Technically the loads in calc_global_*() don't require this since those are the only functions that update 'calc_load_update', but I've added the READ_ONCE() for consistency. Suggested-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Mike Galbraith <umgwanakikbuti@gmail.com> Cc: Morten Rasmussen <morten.rasmussen@arm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vincent Guittot <vincent.guittot@linaro.org> Link: http://lkml.kernel.org/r/20170217120731.11868-3-matt@codeblueprint.co.uk Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-16sched/loadavg: Avoid loadavg spikes caused by delayed NO_HZ accountingMatt Fleming1-2/+2
If we crossed a sample window while in NO_HZ we will add LOAD_FREQ to the pending sample window time on exit, setting the next update not one window into the future, but two. This situation on exiting NO_HZ is described by: this_rq->calc_load_update < jiffies < calc_load_update In this scenario, what we should be doing is: this_rq->calc_load_update = calc_load_update [ next window ] But what we actually do is: this_rq->calc_load_update = calc_load_update + LOAD_FREQ [ next+1 window ] This has the effect of delaying load average updates for potentially up to ~9seconds. This can result in huge spikes in the load average values due to per-cpu uninterruptible task counts being out of sync when accumulated across all CPUs. It's safe to update the per-cpu active count if we wake between sample windows because any load that we left in 'calc_load_idle' will have been zero'd when the idle load was folded in calc_global_load(). This issue is easy to reproduce before, commit 9d89c257dfb9 ("sched/fair: Rewrite runnable load and utilization average tracking") just by forking short-lived process pipelines built from ps(1) and grep(1) in a loop. I'm unable to reproduce the spikes after that commit, but the bug still seems to be present from code review. Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Mike Galbraith <umgwanakikbuti@gmail.com> Cc: Morten Rasmussen <morten.rasmussen@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vincent Guittot <vincent.guittot@linaro.org> Fixes: commit 5167e8d ("sched/nohz: Rewrite and fix load-avg computation -- again") Link: http://lkml.kernel.org/r/20170217120731.11868-2-matt@codeblueprint.co.uk Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-16sched/deadline: Add missing update_rq_clock() in dl_task_timer()Wanpeng Li1-0/+1
The following warning can be triggered by hot-unplugging the CPU on which an active SCHED_DEADLINE task is running on: ------------[ cut here ]------------ WARNING: CPU: 7 PID: 0 at kernel/sched/sched.h:833 replenish_dl_entity+0x71e/0xc40 rq->clock_update_flags < RQCF_ACT_SKIP CPU: 7 PID: 0 Comm: swapper/7 Tainted: G B 4.11.0-rc1+ #24 Hardware name: LENOVO ThinkCentre M8500t-N000/SHARKBAY, BIOS FBKTC1AUS 02/16/2016 Call Trace: <IRQ> dump_stack+0x85/0xc4 __warn+0x172/0x1b0 warn_slowpath_fmt+0xb4/0xf0 ? __warn+0x1b0/0x1b0 ? debug_check_no_locks_freed+0x2c0/0x2c0 ? cpudl_set+0x3d/0x2b0 replenish_dl_entity+0x71e/0xc40 enqueue_task_dl+0x2ea/0x12e0 ? dl_task_timer+0x777/0x990 ? __hrtimer_run_queues+0x270/0xa50 dl_task_timer+0x316/0x990 ? enqueue_task_dl+0x12e0/0x12e0 ? enqueue_task_dl+0x12e0/0x12e0 __hrtimer_run_queues+0x270/0xa50 ? hrtimer_cancel+0x20/0x20 ? hrtimer_interrupt+0x119/0x600 hrtimer_interrupt+0x19c/0x600 ? trace_hardirqs_off+0xd/0x10 local_apic_timer_interrupt+0x74/0xe0 smp_apic_timer_interrupt+0x76/0xa0 apic_timer_interrupt+0x93/0xa0 The DL task will be migrated to a suitable later deadline rq once the DL timer fires and currnet rq is offline. The rq clock of the new rq should be updated. This patch fixes it by updating the rq clock after holding the new rq's rq lock. Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Matt Fleming <matt@codeblueprint.co.uk> Cc: Juri Lelli <juri.lelli@arm.com> 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> Link: http://lkml.kernel.org/r/1488865888-15894-1-git-send-email-wanpeng.li@hotmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-15Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netLinus Torvalds2-39/+86
Pull networking fixes from David Miller: 1) Ensure that mtu is at least IPV6_MIN_MTU in ipv6 VTI tunnel driver, from Steffen Klassert. 2) Fix crashes when user tries to get_next_key on an LPM bpf map, from Alexei Starovoitov. 3) Fix detection of VLAN fitlering feature for bnx2x VF devices, from Michal Schmidt. 4) We can get a divide by zero when TCP socket are morphed into listening state, fix from Eric Dumazet. 5) Fix socket refcounting bugs in skb_complete_wifi_ack() and skb_complete_tx_timestamp(). From Eric Dumazet. 6) Use after free in dccp_feat_activate_values(), also from Eric Dumazet. 7) Like bonding team needs to use ETH_MAX_MTU as netdev->max_mtu, from Jarod Wilson. 8) Fix use after free in vrf_xmit(), from David Ahern. 9) Don't do UDP Fragmentation Offload on IPComp ipsec packets, from Alexey Kodanev. 10) Properly check napi_complete_done() return value in order to decide whether to re-enable IRQs or not in amd-xgbe driver, from Thomas Lendacky. 11) Fix double free of hwmon device in marvell phy driver, from Andrew Lunn. 12) Don't crash on malformed netlink attributes in act_connmark, from Etienne Noss. 13) Don't remove routes with a higher metric in ipv6 ECMP route replace, from Sabrina Dubroca. 14) Don't write into a cloned SKB in ipv6 fragmentation handling, from Florian Westphal. 15) Fix routing redirect races in dccp and tcp, basically the ICMP handler can't modify the socket's cached route in it's locked by the user at this moment. From Jon Maxwell. * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (108 commits) qed: Enable iSCSI Out-of-Order qed: Correct out-of-bound access in OOO history qed: Fix interrupt flags on Rx LL2 qed: Free previous connections when releasing iSCSI qed: Fix mapping leak on LL2 rx flow qed: Prevent creation of too-big u32-chains qed: Align CIDs according to DORQ requirement mlxsw: reg: Fix SPVMLR max record count mlxsw: reg: Fix SPVM max record count net: Resend IGMP memberships upon peer notification. dccp: fix memory leak during tear-down of unsuccessful connection request tun: fix premature POLLOUT notification on tun devices dccp/tcp: fix routing redirect race ucc/hdlc: fix two little issue vxlan: fix ovs support net: use net->count to check whether a netns is alive or not bridge: drop netfilter fake rtable unconditionally ipv6: avoid write to a possibly cloned skb net: wimax/i2400m: fix NULL-deref at probe isdn/gigaset: fix NULL-deref at probe ...
2017-03-15Merge branch 'for-4.11-fixes' of ↵Linus Torvalds2-2/+2
git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup Pull cgroup fixes from Tejun Heo: "Three cgroup fixes. Nothing critical: - the pids controller could trigger suspicious RCU warning spuriously. Fixed. - in the debug controller, %p -> %pK to protect kernel pointer from getting exposed. - documentation formatting fix" * 'for-4.11-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: cgroups: censor kernel pointer in debug files cgroup/pids: remove spurious suspicious RCU usage warning cgroup: Fix indenting in PID controller documentation
2017-03-15Merge branch 'for-4.11-fixes' of ↵Linus Torvalds1-0/+1
git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq Pull workqueue fix from Tejun Heo: "If a delayed work is queued with NULL @wq, workqueue code explodes after the timer expires at which point it's difficult to tell who the culprit was. This actually happened and the offender was net/smc this time. Add an explicit sanity check for it in the queueing path" * 'for-4.11-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq: workqueue: trigger WARN if queue_delayed_work() is called with NULL @wq
2017-03-14futex: Add missing error handling to FUTEX_REQUEUE_PIPeter Zijlstra1-0/+2
Thomas spotted that fixup_pi_state_owner() can return errors and we fail to unlock the rt_mutex in that case. Reported-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Darren Hart <dvhart@linux.intel.com> Cc: juri.lelli@arm.com Cc: bigeasy@linutronix.de Cc: xlpang@redhat.com Cc: rostedt@goodmis.org Cc: mathieu.desnoyers@efficios.com Cc: jdesfossez@efficios.com Cc: dvhart@infradead.org Cc: bristot@redhat.com Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/20170304093558.867401760@infradead.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2017-03-14futex: Fix potential use-after-free in FUTEX_REQUEUE_PIPeter Zijlstra1-9/+11
While working on the futex code, I stumbled over this potential use-after-free scenario. Dmitry triggered it later with syzkaller. pi_mutex is a pointer into pi_state, which we drop the reference on in unqueue_me_pi(). So any access to that pointer after that is bad. Since other sites already do rt_mutex_unlock() with hb->lock held, see for example futex_lock_pi(), simply move the unlock before unqueue_me_pi(). Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Darren Hart <dvhart@linux.intel.com> Cc: juri.lelli@arm.com Cc: bigeasy@linutronix.de Cc: xlpang@redhat.com Cc: rostedt@goodmis.org Cc: mathieu.desnoyers@efficios.com Cc: jdesfossez@efficios.com Cc: dvhart@infradead.org Cc: bristot@redhat.com Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/20170304093558.801744246@infradead.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2017-03-14cpu/hotplug: Serialize callback invocations properSebastian Andrzej Siewior1-14/+14
The setup/remove_state/instance() functions in the hotplug core code are serialized against concurrent CPU hotplug, but unfortunately not serialized against themself. As a consequence a concurrent invocation of these function results in corruption of the callback machinery because two instances try to invoke callbacks on remote cpus at the same time. This results in missing callback invocations and initiator threads waiting forever on the completion. The obvious solution to replace get_cpu_online() with cpu_hotplug_begin() is not possible because at least one callsite calls into these functions from a get_online_cpu() locked region. Extend the protection scope of the cpuhp_state_mutex from solely protecting the state arrays to cover the callback invocation machinery as well. Fixes: 5b7aa87e0482 ("cpu/hotplug: Implement setup/removal interface") Reported-and-tested-by: Bart Van Assche <Bart.VanAssche@sandisk.com> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: hpa@zytor.com Cc: mingo@kernel.org Cc: akpm@linux-foundation.org Cc: torvalds@linux-foundation.org Link: http://lkml.kernel.org/r/20170314150645.g4tdyoszlcbajmna@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2017-03-13Merge branch 'x86-urgent-for-linus' of ↵Linus Torvalds2-9/+5
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fixes from Thomas Gleixner: - a fix for the kexec/purgatory regression which was introduced in the merge window via an innocent sparse fix. We could have reverted that commit, but on deeper inspection it turned out that the whole machinery is neither documented nor robust. So a proper cleanup was done instead - the fix for the TLB flush issue which was discovered recently - a simple typo fix for a reboot quirk * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/tlb: Fix tlb flushing when lguest clears PGE kexec, x86/purgatory: Unbreak it and clean it up x86/reboot/quirks: Fix typo in ASUS EeeBook X205TA reboot quirk
2017-03-10kexec, x86/purgatory: Unbreak it and clean it upThomas Gleixner2-9/+5
The purgatory code defines global variables which are referenced via a symbol lookup in the kexec code (core and arch). A recent commit addressing sparse warnings made these static and thereby broke kexec_file. Why did this happen? Simply because the whole machinery is undocumented and lacks any form of forward declarations. The variable names are unspecific and lack a prefix, so adding forward declarations creates shadow variables in the core code. Aside of that the code relies on magic constants and duplicate struct definitions with no way to ensure that these things stay in sync. The section placement of the purgatory variables happened by chance and not by design. Unbreak kexec and cleanup the mess: - Add proper forward declarations and document the usage - Use common struct definition - Use the proper common defines instead of magic constants - Add a purgatory_ prefix to have a proper name space - Use ARRAY_SIZE() instead of a homebrewn reimplementation - Add proper sections to the purgatory variables [ From Mike ] Fixes: 72042a8c7b01 ("x86/purgatory: Make functions and variables static") Reported-by: Mike Galbraith <<efault@gmx.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Nicholas Mc Guire <der.herr@hofr.at> Cc: Borislav Petkov <bp@alien8.de> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: "Tobin C. Harding" <me@tobin.cc> Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1703101315140.3681@nanos Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2017-03-10Merge branch 'akpm' (patches from Andrew)Linus Torvalds4-4/+3
Merge fixes from Andrew Morton: "26 fixes" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (26 commits) userfaultfd: remove wrong comment from userfaultfd_ctx_get() fat: fix using uninitialized fields of fat_inode/fsinfo_inode sh: cayman: IDE support fix kasan: fix races in quarantine_remove_cache() kasan: resched in quarantine_remove_cache() mm: do not call mem_cgroup_free() from within mem_cgroup_alloc() thp: fix another corner case of munlock() vs. THPs rmap: fix NULL-pointer dereference on THP munlocking mm/memblock.c: fix memblock_next_valid_pfn() userfaultfd: selftest: vm: allow to build in vm/ directory userfaultfd: non-cooperative: userfaultfd_remove revalidate vma in MADV_DONTNEED userfaultfd: non-cooperative: fix fork fctx->new memleak mm/cgroup: avoid panic when init with low memory drivers/md/bcache/util.h: remove duplicate inclusion of blkdev.h mm/vmstats: add thp_split_pud event for clarity include/linux/fs.h: fix unsigned enum warning with gcc-4.2 userfaultfd: non-cooperative: release all ctx in dup_userfaultfd_complete userfaultfd: non-cooperative: robustness check userfaultfd: non-cooperative: rollback userfaultfd_exit x86, mm: unify exit paths in gup_pte_range() ...
2017-03-10userfaultfd: non-cooperative: rollback userfaultfd_exitAndrea Arcangeli1-1/+0
Patch series "userfaultfd non-cooperative further update for 4.11 merge window". Unfortunately I noticed one relevant bug in userfaultfd_exit while doing more testing. I've been doing testing before and this was also tested by kbuild bot and exercised by the selftest, but this bug never reproduced before. I dropped userfaultfd_exit as result. I dropped it because of implementation difficulty in receiving signals in __mmput and because I think -ENOSPC as result from the background UFFDIO_COPY should be enough already. Before I decided to remove userfaultfd_exit, I noticed userfaultfd_exit wasn't exercised by the selftest and when I tried to exercise it, after moving it to a more correct place in __mmput where it would make more sense and where the vma list is stable, it resulted in the event_wait_completion in D state. So then I added the second patch to be sure even if we call userfaultfd_event_wait_completion too late during task exit(), we won't risk to generate tasks in D state. The same check exists in handle_userfault() for the same reason, except it makes a difference there, while here is just a robustness check and it's run under WARN_ON_ONCE. While looking at the userfaultfd_event_wait_completion() function I looked back at its callers too while at it and I think it's not ok to stop executing dup_fctx on the fcs list because we relay on userfaultfd_event_wait_completion to execute userfaultfd_ctx_put(fctx->orig) which is paired against userfaultfd_ctx_get(fctx->orig) in dup_userfault just before list_add(fcs). This change only takes care of fctx->orig but this area also needs further review looking for similar problems in fctx->new. The only patch that is urgent is the first because it's an use after free during a SMP race condition that affects all processes if CONFIG_USERFAULTFD=y. Very hard to reproduce though and probably impossible without SLUB poisoning enabled. This patch (of 3): I once reproduced this oops with the userfaultfd selftest, it's not easily reproducible and it requires SLUB poisoning to reproduce. general protection fault: 0000 [#1] SMP Modules linked in: CPU: 2 PID: 18421 Comm: userfaultfd Tainted: G ------------ T 3.10.0+ #15 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.10.1-0-g8891697-prebuilt.qemu-project.org 04/01/2014 task: ffff8801f83b9440 ti: ffff8801f833c000 task.ti: ffff8801f833c000 RIP: 0010:[<ffffffff81451299>] [<ffffffff81451299>] userfaultfd_exit+0x29/0xa0 RSP: 0018:ffff8801f833fe80 EFLAGS: 00010202 RAX: ffff8801f833ffd8 RBX: 6b6b6b6b6b6b6b6b RCX: ffff8801f83b9440 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8800baf18600 RBP: ffff8801f833fee8 R08: 0000000000000000 R09: 0000000000000001 R10: 0000000000000000 R11: ffffffff8127ceb3 R12: 0000000000000000 R13: ffff8800baf186b0 R14: ffff8801f83b99f8 R15: 00007faed746c700 FS: 0000000000000000(0000) GS:ffff88023fc80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b CR2: 00007faf0966f028 CR3: 0000000001bc6000 CR4: 00000000000006e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: do_exit+0x297/0xd10 SyS_exit+0x17/0x20 tracesys+0xdd/0xe2 Code: 00 00 66 66 66 66 90 55 48 89 e5 41 54 53 48 83 ec 58 48 8b 1f 48 85 db 75 11 eb 73 66 0f 1f 44 00 00 48 8b 5b 10 48 85 db 74 64 <4c> 8b a3 b8 00 00 00 4d 85 e4 74 eb 41 f6 84 24 2c 01 00 00 80 RIP [<ffffffff81451299>] userfaultfd_exit+0x29/0xa0 RSP <ffff8801f833fe80> ---[ end trace 9fecd6dcb442846a ]--- In the debugger I located the "mm" pointer in the stack and walking mm->mmap->vm_next through the end shows the vma->vm_next list is fully consistent and it is null terminated list as expected. So this has to be an SMP race condition where userfaultfd_exit was running while the vma list was being modified by another CPU. When userfaultfd_exit() run one of the ->vm_next pointers pointed to SLAB_POISON (RBX is the vma pointer and is 0x6b6b..). The reason is that it's not running in __mmput but while there are still other threads running and it's not holding the mmap_sem (it can't as it has to wait the even to be received by the manager). So this is an use after free that was happening for all processes. One more implementation problem aside from the race condition: userfaultfd_exit has really to check a flag in mm->flags before walking the vma or it's going to slowdown the exit() path for regular tasks. One more implementation problem: at that point signals can't be delivered so it would also create a task in D state if the manager doesn't read the event. The major design issue: it overall looks superfluous as the manager can check for -ENOSPC in the background transfer: if (mmget_not_zero(ctx->mm)) { [..] } else { return -ENOSPC; } It's safer to roll it back and re-introduce it later if at all. [rppt@linux.vnet.ibm.com: documentation fixup after removal of UFFD_EVENT_EXIT] Link: http://lkml.kernel.org/r/1488345437-4364-1-git-send-email-rppt@linux.vnet.ibm.com Link: http://lkml.kernel.org/r/20170224181957.19736-2-aarcange@redhat.com Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com> Acked-by: Mike Rapoport <rppt@linux.vnet.ibm.com> Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Hillf Danton <hillf.zj@alibaba-inc.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-03-10scripts/spelling.txt: add "overide" pattern and fix typo instancesMasahiro Yamada1-1/+1
Fix typos and add the following to the scripts/spelling.txt: overide||override While we are here, fix the doubled "address" in the touched line Documentation/devicetree/bindings/regulator/ti-abb-regulator.txt. Also, fix the comment block style in the touched hunks in drivers/media/dvb-frontends/drx39xyj/drx_driver.h. Link: http://lkml.kernel.org/r/1481573103-11329-21-git-send-email-yamada.masahiro@socionext.com Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-03-10scripts/spelling.txt: add "disble(d)" pattern and fix typo instancesMasahiro Yamada2-2/+2
Fix typos and add the following to the scripts/spelling.txt: disble||disable disbled||disabled I kept the TSL2563_INT_DISBLED in /drivers/iio/light/tsl2563.c untouched. The macro is not referenced at all, but this commit is touching only comment blocks just in case. Link: http://lkml.kernel.org/r/1481573103-11329-20-git-send-email-yamada.masahiro@socionext.com Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-03-10Merge tag 'pm-4.11-rc2' of ↵Linus Torvalds1-10/+9
git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull power management fixes from Rafael Wysocki: "These fix several issues in the intel_pstate driver and one issue in the schedutil cpufreq governor, clean up that governor a bit and hook up existing code for disabling cpufreq to a new kernel command line option. Specifics: - Three fixes for intel_pstate problems related to the passive mode (in which it acts as a regular cpufreq scaling driver), two for the handling of global P-state limits and one for the handling of the cpu_frequency tracepoint in that mode (Rafael Wysocki). - Three fixes for the handling of P-state limits in intel_pstate in the active mode (Rafael Wysocki). - Introduction of a new cpufreq.off=1 kernel command line argument that will disable cpufreq entirely if passed to the kernel and is simply hooked up to the existing code used by Xen (Len Brown). - Fix for the schedutil cpufreq governor to prevent it from using stale raw frequency values in configurations with mutiple CPUs sharing one policy object and a cleanup for it reducing its overhead slightly (Viresh Kumar)" * tag 'pm-4.11-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: cpufreq: intel_pstate: Do not reinit performance limits in ->setpolicy cpufreq: intel_pstate: Fix intel_pstate_verify_policy() cpufreq: intel_pstate: Fix global settings in active mode cpufreq: Add the "cpufreq.off=1" cmdline option cpufreq: schedutil: Pass sg_policy to get_next_freq() cpufreq: schedutil: move cached_raw_freq to struct sugov_policy cpufreq: intel_pstate: Avoid triggering cpu_frequency tracepoint unnecessarily cpufreq: intel_pstate: Fix intel_cpufreq_verify_policy() cpufreq: intel_pstate: Do not use performance_limits in passive mode
2017-03-10bpf: convert htab map to hlist_nullsAlexei Starovoitov1-34/+60
when all map elements are pre-allocated one cpu can delete and reuse htab_elem while another cpu is still walking the hlist. In such case the lookup may miss the element. Convert hlist to hlist_nulls to avoid such scenario. When bucket lock is taken there is no need to take such precautions, so only convert map_lookup and map_get_next to nulls. The race window is extremely small and only reproducible with explicit udelay() inside lookup_nulls_elem_raw() Similar to hlist add hlist_nulls_for_each_entry_safe() and hlist_nulls_entry_safe() helpers. Fixes: 6c9059817432 ("bpf: pre-allocate hash map elements") Reported-by: Jonathan Perry <jonperry@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-10bpf: fix struct htab_elem layoutAlexei Starovoitov1-5/+20
when htab_elem is removed from the bucket list the htab_elem.hash_node.next field should not be overridden too early otherwise we have a tiny race window between lookup and delete. The bug was discovered by manual code analysis and reproducible only with explicit udelay() in lookup_elem_raw(). Fixes: 6c9059817432 ("bpf: pre-allocate hash map elements") Reported-by: Jonathan Perry <jonperry@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-08sched/headers: fix up header file dependency on <linux/sched/signal.h>Linus Torvalds1-0/+39
The scheduler header file split and cleanups ended up exposing a few nasty header file dependencies, and in particular it showed how we in <linux/wait.h> ended up depending on "signal_pending()", which now comes from <linux/sched/signal.h>. That's a very subtle and annoying dependency, which already caused a semantic merge conflict (see commit e58bc927835a "Pull overlayfs updates from Miklos Szeredi", which added that fixup in the merge commit). It turns out that we can avoid this dependency _and_ improve code generation by moving the guts of the fairly nasty helper #define __wait_event_interruptible_locked() to out-of-line code. The code that includes the signal_pending() check is all in the slow-path where we actually go to sleep waiting for the event anyway, so using a helper function is the right thing to do. Using a helper function is also what we already did for the non-locked versions, see the "__wait_event*()" macros and the "prepare_to_wait*()" set of helper functions. We might want to try to unify all these macro games, we have a _lot_ of subtly different wait-event loops. But this is the minimal patch to fix the annoying header dependency. Acked-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-03-08Merge branch 'timers-urgent-for-linus' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull timer fixes from Ingo Molnar: "This includes a fix for lockups caused by incorrect nsecs related cleanup, and a capabilities check fix for timerfd" * 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: jiffies: Revert bogus conversion of NSEC_PER_SEC to TICK_NSEC timerfd: Only check CAP_WAKE_ALARM when it is needed
2017-03-08Merge branch 'sched-urgent-for-linus' of ↵Linus Torvalds3-4/+14
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler fixes from Ingo Molnar: "A fix for KVM's scheduler clock which (erroneously) was always marked unstable, a fix for RT/DL load balancing, plus latency fixes" * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/clock, x86/tsc: Rework the x86 'unstable' sched_clock() interface sched/core: Fix pick_next_task() for RT,DL sched/fair: Make select_idle_cpu() more aggressive
2017-03-08Merge branch 'perf-urgent-for-linus' of ↵Linus Torvalds4-12/+12
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf fixes from Ingo Molnar: "This includes a fix for a crash if certain special addresses are kprobed, plus does a rename of two Kconfig variables that were a minor misnomer" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf/core: Rename CONFIG_[UK]PROBE_EVENT to CONFIG_[UK]PROBE_EVENTS kprobes/x86: Fix kernel panic when certain exception-handling addresses are probed
2017-03-08Merge branch 'locking-urgent-for-linus' of ↵Linus Torvalds2-5/+12
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull locking fixes from Ingo Molnar: - Change the new refcount_t warnings from WARN() to WARN_ONCE() - two ww_mutex fixes - plus a new lockdep self-consistency check for a bug that triggered in practice * 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: locking/ww_mutex: Adjust the lock number for stress test locking/lockdep: Add nest_lock integrity test locking/ww_mutex: Replace cpu_relax() with cond_resched() for tests locking/refcounts: Change WARN() to WARN_ONCE()
2017-03-07Merge branch 'for-linus' of ↵Linus Torvalds1-7/+11
git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace Pull namespace fix from Eric Biederman: "This fixes a race between put_ucounts and get_ucounts that can cause a use after free. The fix works by simplifying the code and so there is not even a temptation to be clever and play spinlock vs atomic reference games" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: ucount: Remove the atomicity from ucount->count
2017-03-07Merge tag 'trace-v4.11-rc1' of ↵Linus Torvalds1-5/+18
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing fixes from Steven Rostedt: "There was some breakage with the changes for jump labels in the 4.11 merge window: - powerpc broke as jump labels uses the two LSB bits as flags in initialization. A check was added to make sure that all jump label entries were 4 bytes aligned, but powerpc didn't work that way for modules. Adding an alignment in the module linker script appeared to be the best solution. - Jump labels also added an anonymous union to access those LSB bits as a normal long. But because this structure had static initialization, it broke older compilers that could not statically initialize anonymous unions without brackets. - The command line parameter for setting function graph filter broke the "EMPTY_HASH" descriptor by modifying it instead of creating a new hash to hold the entries. - The command line parameter ftrace_graph_max_depth was added to allow its setting at boot time. It uses existing code and only the command line hook was added. This is not really a fix, but as it uses existing code without affecting anything else, I added it to this release. It was ready before the merge window closed, but I wanted to let it sit in linux-next for a couple of days first" * tag 'trace-v4.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: ftrace/graph: Add ftrace_graph_max_depth kernel parameter tracing: Add #undef to fix compile error jump_label: Add comment about initialization order for anonymous unions jump_label: Fix anonymous union initialization module: set __jump_table alignment to 8 ftrace/graph: Do not modify the EMPTY_HASH for the function_graph filter tracing: Fix code comment for ftrace_ops_get_func()
2017-03-07jiffies: Revert bogus conversion of NSEC_PER_SEC to TICK_NSECFrederic Weisbecker1-1/+1
commit 93825f2ec736 converted NSEC_PER_SEC to TICK_NSEC because the author confused NSEC_PER_JIFFY with NSEC_PER_SEC. As a result, the calculation of refined jiffies got broken, triggering lockups. Fixes: 93825f2ec736 ("jiffies: Reuse TICK_NSEC instead of NSEC_PER_JIFFY") Reported-and-tested-by: Meelis Roos <mroos@linux.ee> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1488880534-3777-1-git-send-email-fweisbec@gmail.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2017-03-07ucount: Remove the atomicity from ucount->countEric W. Biederman1-7/+11
Always increment/decrement ucount->count under the ucounts_lock. The increments are there already and moving the decrements there means the locking logic of the code is simpler. This simplification in the locking logic fixes a race between put_ucounts and get_ucounts that could result in a use-after-free because the count could go zero then be found by get_ucounts and then be freed by put_ucounts. A bug presumably this one was found by a combination of syzkaller and KASAN. JongWhan Kim reported the syzkaller failure and Dmitry Vyukov spotted the race in the code. Cc: stable@vger.kernel.org Fixes: f6b2db1a3e8d ("userns: Make the count of user namespaces per user") Reported-by: JongHwan Kim <zzoru007@gmail.com> Reported-by: Dmitry Vyukov <dvyukov@google.com> Reviewed-by: Andrei Vagin <avagin@gmail.com> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2017-03-06workqueue: trigger WARN if queue_delayed_work() is called with NULL @wqTejun Heo1-0/+1
If queue_delayed_work() gets called with NULL @wq, the kernel will oops asynchronuosly on timer expiration which isn't too helpful in tracking down the offender. This actually happened with smc. __queue_delayed_work() already does several input sanity checks synchronously. Add NULL @wq check. Reported-by: Dave Jones <davej@codemonkey.org.uk> Link: http://lkml.kernel.org/r/20170227171439.jshx3qplflyrgcv7@codemonkey.org.uk Signed-off-by: Tejun Heo <tj@kernel.org>
2017-03-06cgroups: censor kernel pointer in debug filesKees Cook1-1/+1
As found in grsecurity, this avoids exposing a kernel pointer through the cgroup debug entries. Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Tejun Heo <tj@kernel.org>
2017-03-06cgroup/pids: remove spurious suspicious RCU usage warningTejun Heo1-1/+1
pids_can_fork() is special in that the css association is guaranteed to be stable throughout the function and thus doesn't need RCU protection around task_css access. When determining the css to charge the pid, task_css_check() is used to override the RCU sanity check. While adding a warning message on fork rejection from pids limit, 135b8b37bd91 ("cgroup: Add pids controller event when fork fails because of pid limit") incorrectly added a task_css access which is neither RCU protected or explicitly annotated. This triggers the following suspicious RCU usage warning when RCU debugging is enabled. cgroup: fork rejected by pids controller in =============================== [ ERR: suspicious RCU usage. ] 4.10.0-work+ #1 Not tainted ------------------------------- ./include/linux/cgroup.h:435 suspicious rcu_dereference_check() usage! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 0 1 lock held by bash/1748: #0: (&cgroup_threadgroup_rwsem){+++++.}, at: [<ffffffff81052c96>] _do_fork+0xe6/0x6e0 stack backtrace: CPU: 3 PID: 1748 Comm: bash Not tainted 4.10.0-work+ #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.9.3-1.fc25 04/01/2014 Call Trace: dump_stack+0x68/0x93 lockdep_rcu_suspicious+0xd7/0x110 pids_can_fork+0x1c7/0x1d0 cgroup_can_fork+0x67/0xc0 copy_process.part.58+0x1709/0x1e90 _do_fork+0xe6/0x6e0 SyS_clone+0x19/0x20 do_syscall_64+0x5c/0x140 entry_SYSCALL64_slow_path+0x25/0x25 RIP: 0033:0x7f7853fab93a RSP: 002b:00007ffc12d05c90 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f7853fab93a RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 00007ffc12d05cc0 R08: 0000000000000000 R09: 00007f78548db700 R10: 00007f78548db9d0 R11: 0000000000000246 R12: 00000000000006d4 R13: 0000000000000001 R14: 0000000000000000 R15: 000055e3ebe2c04d /asdf There's no reason to dereference task_css again here when the associated css is already available. Fix it by replacing the task_cgroup() call with css->cgroup. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Mike Galbraith <efault@gmx.de> Fixes: 135b8b37bd91 ("cgroup: Add pids controller event when fork fails because of pid limit") Cc: Kenny Yu <kennyyu@fb.com> Cc: stable@vger.kernel.org # v4.8+ Signed-off-by: Tejun Heo <tj@kernel.org>
2017-03-06bpf: add get_next_key callback to LPM mapAlexei Starovoitov1-0/+6
map_get_next_key callback is mandatory. Supply dummy handler. Fixes: b95a5c4db09b ("bpf: add a longest prefix match trie map implementation") Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-06cpufreq: schedutil: Pass sg_policy to get_next_freq()Viresh Kumar1-6/+5
get_next_freq() uses sg_cpu only to get sg_policy, which the callers of get_next_freq() already have. Pass sg_policy instead of sg_cpu to get_next_freq(), to make it more efficient. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2017-03-06cpufreq: schedutil: move cached_raw_freq to struct sugov_policyViresh Kumar1-4/+4
cached_raw_freq applies to the entire cpufreq policy and not individual CPUs. Apart from wasting per-cpu memory, it is actually wrong to keep it in struct sugov_cpu as we may end up comparing next_freq with a stale cached_raw_freq of a random CPU. Move cached_raw_freq to struct sugov_policy. Fixes: 5cbea46984d6 (cpufreq: schedutil: map raw required frequency to driver frequency) Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2017-03-05Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netLinus Torvalds1-1/+1
Pull networking fixes from David Miller: 1) Fix double-free in batman-adv, from Sven Eckelmann. 2) Fix packet stats for fast-RX path, from Joannes Berg. 3) Netfilter's ip_route_me_harder() doesn't handle request sockets properly, fix from Florian Westphal. 4) Fix sendmsg deadlock in rxrpc, from David Howells. 5) Add missing RCU locking to transport hashtable scan, from Xin Long. 6) Fix potential packet loss in mlxsw driver, from Ido Schimmel. 7) Fix race in NAPI handling between poll handlers and busy polling, from Eric Dumazet. 8) TX path in vxlan and geneve need proper RCU locking, from Jakub Kicinski. 9) SYN processing in DCCP and TCP need to disable BH, from Eric Dumazet. 10) Properly handle net_enable_timestamp() being invoked from IRQ context, also from Eric Dumazet. 11) Fix crash on device-tree systems in xgene driver, from Alban Bedel. 12) Do not call sk_free() on a locked socket, from Arnaldo Carvalho de Melo. 13) Fix use-after-free in netvsc driver, from Dexuan Cui. 14) Fix max MTU setting in bonding driver, from WANG Cong. 15) xen-netback hash table can be allocated from softirq context, so use GFP_ATOMIC. From Anoob Soman. 16) Fix MAC address change bug in bgmac driver, from Hari Vyas. 17) strparser needs to destroy strp_wq on module exit, from WANG Cong. * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (69 commits) strparser: destroy workqueue on module exit sfc: fix IPID endianness in TSOv2 sfc: avoid max() in array size rds: remove unnecessary returned value check rxrpc: Fix potential NULL-pointer exception nfp: correct DMA direction in XDP DMA sync nfp: don't tell FW about the reserved buffer space net: ethernet: bgmac: mac address change bug net: ethernet: bgmac: init sequence bug xen-netback: don't vfree() queues under spinlock xen-netback: keep a local pointer for vif in backend_disconnect() netfilter: nf_tables: don't call nfnetlink_set_err() if nfnetlink_send() fails netfilter: nft_set_rbtree: incorrect assumption on lower interval lookups netfilter: nf_conntrack_sip: fix wrong memory initialisation can: flexcan: fix typo in comment can: usb_8dev: Fix memory leak of priv->cmd_msg_buffer can: gs_usb: fix coding style can: gs_usb: Don't use stack memory for USB transfers ixgbe: Limit use of 2K buffers on architectures with 256B or larger cache lines ixgbe: update the rss key on h/w, when ethtool ask for it ...
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