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2013-10-13irq: Force hardirq exit's softirq processing on its own stackFrederic Weisbecker
commit ded797547548a5b8e7b92383a41e4c0e6b0ecb7f upstream. The commit facd8b80c67a3cf64a467c4a2ac5fb31f2e6745b ("irq: Sanitize invoke_softirq") converted irq exit calls of do_softirq() to __do_softirq() on all architectures, assuming it was only used there for its irq disablement properties. But as a side effect, the softirqs processed in the end of the hardirq are always called on the inline current stack that is used by irq_exit() instead of the softirq stack provided by the archs that override do_softirq(). The result is mostly safe if the architecture runs irq_exit() on a separate irq stack because then softirqs are processed on that same stack that is near empty at this stage (assuming hardirq aren't nesting). Otherwise irq_exit() runs in the task stack and so does the softirq too. The interrupted call stack can be randomly deep already and the softirq can dig through it even further. To add insult to the injury, this softirq can be interrupted by a new hardirq, maximizing the chances for a stack overrun as reported in powerpc for example: do_IRQ: stack overflow: 1920 CPU: 0 PID: 1602 Comm: qemu-system-ppc Not tainted 3.10.4-300.1.fc19.ppc64p7 #1 Call Trace: [c0000000050a8740] .show_stack+0x130/0x200 (unreliable) [c0000000050a8810] .dump_stack+0x28/0x3c [c0000000050a8880] .do_IRQ+0x2b8/0x2c0 [c0000000050a8930] hardware_interrupt_common+0x154/0x180 --- Exception: 501 at .cp_start_xmit+0x3a4/0x820 [8139cp] LR = .cp_start_xmit+0x390/0x820 [8139cp] [c0000000050a8d40] .dev_hard_start_xmit+0x394/0x640 [c0000000050a8e00] .sch_direct_xmit+0x110/0x260 [c0000000050a8ea0] .dev_queue_xmit+0x260/0x630 [c0000000050a8f40] .br_dev_queue_push_xmit+0xc4/0x130 [bridge] [c0000000050a8fc0] .br_dev_xmit+0x198/0x270 [bridge] [c0000000050a9070] .dev_hard_start_xmit+0x394/0x640 [c0000000050a9130] .dev_queue_xmit+0x428/0x630 [c0000000050a91d0] .ip_finish_output+0x2a4/0x550 [c0000000050a9290] .ip_local_out+0x50/0x70 [c0000000050a9310] .ip_queue_xmit+0x148/0x420 [c0000000050a93b0] .tcp_transmit_skb+0x4e4/0xaf0 [c0000000050a94a0] .__tcp_ack_snd_check+0x7c/0xf0 [c0000000050a9520] .tcp_rcv_established+0x1e8/0x930 [c0000000050a95f0] .tcp_v4_do_rcv+0x21c/0x570 [c0000000050a96c0] .tcp_v4_rcv+0x734/0x930 [c0000000050a97a0] .ip_local_deliver_finish+0x184/0x360 [c0000000050a9840] .ip_rcv_finish+0x148/0x400 [c0000000050a98d0] .__netif_receive_skb_core+0x4f8/0xb00 [c0000000050a99d0] .netif_receive_skb+0x44/0x110 [c0000000050a9a70] .br_handle_frame_finish+0x2bc/0x3f0 [bridge] [c0000000050a9b20] .br_nf_pre_routing_finish+0x2ac/0x420 [bridge] [c0000000050a9bd0] .br_nf_pre_routing+0x4dc/0x7d0 [bridge] [c0000000050a9c70] .nf_iterate+0x114/0x130 [c0000000050a9d30] .nf_hook_slow+0xb4/0x1e0 [c0000000050a9e00] .br_handle_frame+0x290/0x330 [bridge] [c0000000050a9ea0] .__netif_receive_skb_core+0x34c/0xb00 [c0000000050a9fa0] .netif_receive_skb+0x44/0x110 [c0000000050aa040] .napi_gro_receive+0xe8/0x120 [c0000000050aa0c0] .cp_rx_poll+0x31c/0x590 [8139cp] [c0000000050aa1d0] .net_rx_action+0x1dc/0x310 [c0000000050aa2b0] .__do_softirq+0x158/0x330 [c0000000050aa3b0] .irq_exit+0xc8/0x110 [c0000000050aa430] .do_IRQ+0xdc/0x2c0 [c0000000050aa4e0] hardware_interrupt_common+0x154/0x180 --- Exception: 501 at .bad_range+0x1c/0x110 LR = .get_page_from_freelist+0x908/0xbb0 [c0000000050aa7d0] .list_del+0x18/0x50 (unreliable) [c0000000050aa850] .get_page_from_freelist+0x908/0xbb0 [c0000000050aa9e0] .__alloc_pages_nodemask+0x21c/0xae0 [c0000000050aaba0] .alloc_pages_vma+0xd0/0x210 [c0000000050aac60] .handle_pte_fault+0x814/0xb70 [c0000000050aad50] .__get_user_pages+0x1a4/0x640 [c0000000050aae60] .get_user_pages_fast+0xec/0x160 [c0000000050aaf10] .__gfn_to_pfn_memslot+0x3b0/0x430 [kvm] [c0000000050aafd0] .kvmppc_gfn_to_pfn+0x64/0x130 [kvm] [c0000000050ab070] .kvmppc_mmu_map_page+0x94/0x530 [kvm] [c0000000050ab190] .kvmppc_handle_pagefault+0x174/0x610 [kvm] [c0000000050ab270] .kvmppc_handle_exit_pr+0x464/0x9b0 [kvm] [c0000000050ab320] kvm_start_lightweight+0x1ec/0x1fc [kvm] [c0000000050ab4f0] .kvmppc_vcpu_run_pr+0x168/0x3b0 [kvm] [c0000000050ab9c0] .kvmppc_vcpu_run+0xc8/0xf0 [kvm] [c0000000050aba50] .kvm_arch_vcpu_ioctl_run+0x5c/0x1a0 [kvm] [c0000000050abae0] .kvm_vcpu_ioctl+0x478/0x730 [kvm] [c0000000050abc90] .do_vfs_ioctl+0x4ec/0x7c0 [c0000000050abd80] .SyS_ioctl+0xd4/0xf0 [c0000000050abe30] syscall_exit+0x0/0x98 Since this is a regression, this patch proposes a minimalistic and low-risk solution by blindly forcing the hardirq exit processing of softirqs on the softirq stack. This way we should reduce significantly the opportunities for task stack overflow dug by softirqs. Longer term solutions may involve extending the hardirq stack coverage to irq_exit(), etc... Reported-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@au1.ibm.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul Mackerras <paulus@au1.ibm.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: James E.J. Bottomley <jejb@parisc-linux.org> Cc: Helge Deller <deller@gmx.de> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: David S. Miller <davem@davemloft.net> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-13kernel/kmod.c: check for NULL in call_usermodehelper_exec()Tetsuo Handa
commit 4c1c7be95c345cf2ad537a0c48e9aeadc7304527 upstream. If /proc/sys/kernel/core_pattern contains only "|", a NULL pointer dereference happens upon core dump because argv_split("") returns argv[0] == NULL. This bug was once fixed by commit 264b83c07a84 ("usermodehelper: check subprocess_info->path != NULL") but was by error reintroduced by commit 7f57cfa4e2aa ("usermodehelper: kill the sub_info->path[0] check"). This bug seems to exist since 2.6.19 (the version which core dump to pipe was added). Depending on kernel version and config, some side effect might happen immediately after this oops (e.g. kernel panic with 2.6.32-358.18.1.el6). Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Acked-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-05irq: Always define devm_{request_threaded,free}_irq()Ben Hutchings
This is only needed for 3.11, as s390 has now been changed to use the generic IRQ code upstream. These functions are currently defined only if CONFIG_GENERIC_HARDIRQS is enabled. But they are still needed on s390 which has its own IRQ management. References: https://buildd.debian.org/status/fetch.php?pkg=linux&arch=s390&ver=3.11%7Erc4-1%7Eexp1&stamp=1376009959 Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2013-10-05kernel/reboot.c: re-enable the function of variable reboot_defaultChuansheng Liu
commit e2f0b88e84eed9cf9797f0a88c8012ee0b885a6d upstream. Commit 1b3a5d02ee07 ("reboot: move arch/x86 reboot= handling to generic kernel") did some cleanup for reboot= command line, but it made the reboot_default inoperative. The default value of variable reboot_default should be 1, and if command line reboot= is not set, system will use the default reboot mode. [akpm@linux-foundation.org: fix comment layout] Signed-off-by: Li Fei <fei.li@intel.com> Signed-off-by: liu chuansheng <chuansheng.liu@intel.com> Acked-by: Robin Holt <robinmholt@linux.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-01audit: fix endless wait in audit_log_start()Konstantin Khlebnikov
commit 8ac1c8d5deba65513b6a82c35e89e73996c8e0d6 upstream. After commit 829199197a43 ("kernel/audit.c: avoid negative sleep durations") audit emitters will block forever if userspace daemon cannot handle backlog. After the timeout the waiting loop turns into busy loop and runs until daemon dies or returns back to work. This is a minimal patch for that bug. Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org> Cc: Luiz Capitulino <lcapitulino@redhat.com> Cc: Richard Guy Briggs <rgb@redhat.com> Cc: Eric Paris <eparis@redhat.com> Cc: Chuck Anderson <chuck.anderson@oracle.com> Cc: Dan Duval <dan.duval@oracle.com> Cc: Dave Kleikamp <dave.kleikamp@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Jonghwan Choi <jhbird.choi@samsung.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-01sched/fair: Fix small race where child->se.parent,cfs_rq might point to ↵Daisuke Nishimura
invalid ones commit 6c9a27f5da9609fca46cb2b183724531b48f71ad upstream. There is a small race between copy_process() and cgroup_attach_task() where child->se.parent,cfs_rq points to invalid (old) ones. parent doing fork() | someone moving the parent to another cgroup -------------------------------+--------------------------------------------- copy_process() + dup_task_struct() -> parent->se is copied to child->se. se.parent,cfs_rq of them point to old ones. cgroup_attach_task() + cgroup_task_migrate() -> parent->cgroup is updated. + cpu_cgroup_attach() + sched_move_task() + task_move_group_fair() +- set_task_rq() -> se.parent,cfs_rq of parent are updated. + cgroup_fork() -> parent->cgroup is copied to child->cgroup. (*1) + sched_fork() + task_fork_fair() -> se.parent,cfs_rq of child are accessed while they point to old ones. (*2) In the worst case, this bug can lead to "use-after-free" and cause a panic, because it's new cgroup's refcount that is incremented at (*1), so the old cgroup(and related data) can be freed before (*2). In fact, a panic caused by this bug was originally caught in RHEL6.4. BUG: unable to handle kernel NULL pointer dereference at (null) IP: [<ffffffff81051e3e>] sched_slice+0x6e/0xa0 [...] Call Trace: [<ffffffff81051f25>] place_entity+0x75/0xa0 [<ffffffff81056a3a>] task_fork_fair+0xaa/0x160 [<ffffffff81063c0b>] sched_fork+0x6b/0x140 [<ffffffff8106c3c2>] copy_process+0x5b2/0x1450 [<ffffffff81063b49>] ? wake_up_new_task+0xd9/0x130 [<ffffffff8106d2f4>] do_fork+0x94/0x460 [<ffffffff81072a9e>] ? sys_wait4+0xae/0x100 [<ffffffff81009598>] sys_clone+0x28/0x30 [<ffffffff8100b393>] stub_clone+0x13/0x20 [<ffffffff8100b072>] ? system_call_fastpath+0x16/0x1b Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/039601ceae06$733d3130$59b79390$@mxp.nes.nec.co.jp Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-01sched/cputime: Do not scale when utime == 0Stanislaw Gruszka
commit 5a8e01f8fa51f5cbce8f37acc050eb2319d12956 upstream. scale_stime() silently assumes that stime < rtime, otherwise when stime == rtime and both values are big enough (operations on them do not fit in 32 bits), the resulting scaling stime can be bigger than rtime. In consequence utime = rtime - stime results in negative value. User space visible symptoms of the bug are overflowed TIME values on ps/top, for example: $ ps aux | grep rcu root 8 0.0 0.0 0 0 ? S 12:42 0:00 [rcuc/0] root 9 0.0 0.0 0 0 ? S 12:42 0:00 [rcub/0] root 10 62422329 0.0 0 0 ? R 12:42 21114581:37 [rcu_preempt] root 11 0.1 0.0 0 0 ? S 12:42 0:02 [rcuop/0] root 12 62422329 0.0 0 0 ? S 12:42 21114581:35 [rcuop/1] root 10 62422329 0.0 0 0 ? R 12:42 21114581:37 [rcu_preempt] or overflowed utime values read directly from /proc/$PID/stat Reference: https://lkml.org/lkml/2013/8/20/259 Reported-and-tested-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com> Cc: stable@vger.kernel.org Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Borislav Petkov <bp@alien8.de> Link: http://lkml.kernel.org/r/20130904131602.GC2564@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-01timekeeping: Fix HRTICK related deadlock from ntp lock changesJohn Stultz
commit 7bd36014460f793c19e7d6c94dab67b0afcfcb7f upstream. Gerlando Falauto reported that when HRTICK is enabled, it is possible to trigger system deadlocks. These were hard to reproduce, as HRTICK has been broken in the past, but seemed to be connected to the timekeeping_seq lock. Since seqlock/seqcount's aren't supported w/ lockdep, I added some extra spinlock based locking and triggered the following lockdep output: [ 15.849182] ntpd/4062 is trying to acquire lock: [ 15.849765] (&(&pool->lock)->rlock){..-...}, at: [<ffffffff810aa9b5>] __queue_work+0x145/0x480 [ 15.850051] [ 15.850051] but task is already holding lock: [ 15.850051] (timekeeper_lock){-.-.-.}, at: [<ffffffff810df6df>] do_adjtimex+0x7f/0x100 <snip> [ 15.850051] Chain exists of: &(&pool->lock)->rlock --> &p->pi_lock --> timekeeper_lock [ 15.850051] Possible unsafe locking scenario: [ 15.850051] [ 15.850051] CPU0 CPU1 [ 15.850051] ---- ---- [ 15.850051] lock(timekeeper_lock); [ 15.850051] lock(&p->pi_lock); [ 15.850051] lock(timekeeper_lock); [ 15.850051] lock(&(&pool->lock)->rlock); [ 15.850051] [ 15.850051] *** DEADLOCK *** The deadlock was introduced by 06c017fdd4dc48451a ("timekeeping: Hold timekeepering locks in do_adjtimex and hardpps") in 3.10 This patch avoids this deadlock, by moving the call to schedule_delayed_work() outside of the timekeeper lock critical section. Reported-by: Gerlando Falauto <gerlando.falauto@keymile.com> Tested-by: Lin Ming <minggr@gmail.com> Signed-off-by: John Stultz <john.stultz@linaro.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Link: http://lkml.kernel.org/r/1378943457-27314-1-git-send-email-john.stultz@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-09-26pidns: fix vfork() after unshare(CLONE_NEWPID)Oleg Nesterov
commit e79f525e99b04390ca4d2366309545a836c03bf1 upstream. Commit 8382fcac1b81 ("pidns: Outlaw thread creation after unshare(CLONE_NEWPID)") nacks CLONE_VM if the forking process unshared pid_ns, this obviously breaks vfork: int main(void) { assert(unshare(CLONE_NEWUSER | CLONE_NEWPID) == 0); assert(vfork() >= 0); _exit(0); return 0; } fails without this patch. Change this check to use CLONE_SIGHAND instead. This also forbids CLONE_THREAD automatically, and this is what the comment implies. We could probably even drop CLONE_SIGHAND and use CLONE_THREAD, but it would be safer to not do this. The current check denies CLONE_SIGHAND implicitely and there is no reason to change this. Eric said "CLONE_SIGHAND is fine. CLONE_THREAD would be even better. Having shared signal handling between two different pid namespaces is the case that we are fundamentally guarding against." Signed-off-by: Oleg Nesterov <oleg@redhat.com> Reported-by: Colin Walters <walters@redhat.com> Acked-by: Andy Lutomirski <luto@amacapital.net> Reviewed-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-09-26pidns: Fix hang in zap_pid_ns_processes by sending a potentially extra wakeupEric W. Biederman
commit a606488513543312805fab2b93070cefe6a3016c upstream. Serge Hallyn <serge.hallyn@ubuntu.com> writes: > Since commit af4b8a83add95ef40716401395b44a1b579965f4 it's been > possible to get into a situation where a pidns reaper is > <defunct>, reparented to host pid 1, but never reaped. How to > reproduce this is documented at > > https://bugs.launchpad.net/ubuntu/+source/lxc/+bug/1168526 > (and see > https://bugs.launchpad.net/ubuntu/+source/lxc/+bug/1168526/comments/13) > In short, run repeated starts of a container whose init is > > Process.exit(0); > > sysrq-t when such a task is playing zombie shows: > > [ 131.132978] init x ffff88011fc14580 0 2084 2039 0x00000000 > [ 131.132978] ffff880116e89ea8 0000000000000002 ffff880116e89fd8 0000000000014580 > [ 131.132978] ffff880116e89fd8 0000000000014580 ffff8801172a0000 ffff8801172a0000 > [ 131.132978] ffff8801172a0630 ffff88011729fff0 ffff880116e14650 ffff88011729fff0 > [ 131.132978] Call Trace: > [ 131.132978] [<ffffffff816f6159>] schedule+0x29/0x70 > [ 131.132978] [<ffffffff81064591>] do_exit+0x6e1/0xa40 > [ 131.132978] [<ffffffff81071eae>] ? signal_wake_up_state+0x1e/0x30 > [ 131.132978] [<ffffffff8106496f>] do_group_exit+0x3f/0xa0 > [ 131.132978] [<ffffffff810649e4>] SyS_exit_group+0x14/0x20 > [ 131.132978] [<ffffffff8170102f>] tracesys+0xe1/0xe6 > > Further debugging showed that every time this happened, zap_pid_ns_processes() > started with nr_hashed being 3, while we were expecting it to drop to 2. > Any time it didn't happen, nr_hashed was 1 or 2. So the reaper was > waiting for nr_hashed to become 2, but free_pid() only wakes the reaper > if nr_hashed hits 1. The issue is that when the task group leader of an init process exits before other tasks of the init process when the init process finally exits it will be a secondary task sleeping in zap_pid_ns_processes and waiting to wake up when the number of hashed pids drops to two. This case waits forever as free_pid only sends a wake up when the number of hashed pids drops to 1. To correct this the simple strategy of sending a possibly unncessary wake up when the number of hashed pids drops to 2 is adopted. Sending one extraneous wake up is relatively harmless, at worst we waste a little cpu time in the rare case when a pid namespace appropaches exiting. We can detect the case when the pid namespace drops to just two pids hashed race free in free_pid. Dereferencing pid_ns->child_reaper with the pidmap_lock held is safe without out the tasklist_lock because it is guaranteed that the detach_pid will be called on the child_reaper before it is freed and detach_pid calls __change_pid which calls free_pid which takes the pidmap_lock. __change_pid only calls free_pid if this is the last use of the pid. For a thread that is not the thread group leader the threads pid will only ever have one user because a threads pid is not allowed to be the pid of a process, of a process group or a session. For a thread that is a thread group leader all of the other threads of that process will be reaped before it is allowed for the thread group leader to be reaped ensuring there will only be one user of the threads pid as a process pid. Furthermore because the thread is the init process of a pid namespace all of the other processes in the pid namespace will have also been already freed leading to the fact that the pid will not be used as a session pid or a process group pid for any other running process. Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Tested-by: Serge Hallyn <serge.hallyn@canonical.com> Reported-by: Serge Hallyn <serge.hallyn@ubuntu.com> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-09-26uprobes: Fix utask->depth accounting in handle_trampoline()Oleg Nesterov
commit 878b5a6efd38030c7a90895dc8346e8fb1e09b4c upstream. Currently utask->depth is simply the number of allocated/pending return_instance's in uprobe_task->return_instances list. handle_trampoline() should decrement this counter every time we handle/free an instance, but due to typo it does this only if ->chained == T. This means that in the likely case this counter is never decremented and the probed task can't report more than MAX_URETPROBE_DEPTH events. Reported-by: Mikhail Kulemin <Mikhail.Kulemin@ru.ibm.com> Reported-by: Hemant Kumar Shaw <hkshaw@linux.vnet.ibm.com> Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Anton Arapov <anton@redhat.com> Cc: masami.hiramatsu.pt@hitachi.com Cc: srikar@linux.vnet.ibm.com Cc: systemtap@sourceware.org Link: http://lkml.kernel.org/r/20130911154726.GA8093@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-08-30Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netLinus Torvalds
Pull networking fixes from David Miller: 1) There was a simplification in the ipv6 ndisc packet sending attempted here, which avoided using memory accounting on the per-netns ndisc socket for sending NDISC packets. It did fix some important issues, but it causes regressions so it gets reverted here too. Specifically, the problem with this change is that the IPV6 output path really depends upon there being a valid skb->sk attached. The reason we want to do this change in some form when we figure out how to do it right, is that if a device goes down the ndisc_sk socket send queue will fill up and block NDISC packets that we want to send to other devices too. That's really bad behavior. Hopefully Thomas can come up with a better version of this change. 2) Fix a severe TCP performance regression by reverting a change made to dev_pick_tx() quite some time ago. From Eric Dumazet. 3) TIPC returns wrongly signed error codes, fix from Erik Hugne. 4) Fix OOPS when doing IPSEC over ipv4 tunnels due to orphaning the skb->sk too early. Fix from Li Hongjun. 5) RAW ipv4 sockets can use the wrong routing key during lookup, from Chris Clark. 6) Similar to #1 revert an older change that tried to use plain alloc_skb() for SYN/ACK TCP packets, this broke the netfilter owner mark which needs to see the skb->sk for such frames. From Phil Oester. 7) BNX2x driver bug fixes from Ariel Elior and Yuval Mintz, specifically in the handling of virtual functions. 8) IPSEC path error propagations to sockets is not done properly when we have v4 in v6, and v6 in v4 type rules. Fix from Hannes Frederic Sowa. 9) Fix missing channel context release in mac80211, from Johannes Berg. 10) Fix network namespace handing wrt. SCM_RIGHTS, from Andy Lutomirski. 11) Fix usage of bogus NAPI weight in jme, netxen, and ps3_gelic drivers. From Michal Schmidt. 12) Hopefully a complete and correct fix for the genetlink dump locking and module reference counting. From Pravin B Shelar. 13) sk_busy_loop() must do a cpu_relax(), from Eliezer Tamir. 14) Fix handling of timestamp offset when restoring a snapshotted TCP socket. From Andrew Vagin. * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (44 commits) net: fec: fix time stamping logic after napi conversion net: bridge: convert MLDv2 Query MRC into msecs_to_jiffies for max_delay mISDN: return -EINVAL on error in dsp_control_req() net: revert 8728c544a9c ("net: dev_pick_tx() fix") Revert "ipv6: Don't depend on per socket memory for neighbour discovery messages" ipv4 tunnels: fix an oops when using ipip/sit with IPsec tipc: set sk_err correctly when connection fails tcp: tcp_make_synack() should use sock_wmalloc bridge: separate querier and query timer into IGMP/IPv4 and MLD/IPv6 ones ipv6: Don't depend on per socket memory for neighbour discovery messages ipv4: sendto/hdrincl: don't use destination address found in header tcp: don't apply tsoffset if rcv_tsecr is zero tcp: initialize rcv_tstamp for restored sockets net: xilinx: fix memleak net: usb: Add HP hs2434 device to ZLP exception table net: add cpu_relax to busy poll loop net: stmmac: fixed the pbl setting with DT genl: Hold reference on correct module while netlink-dump. genl: Fix genl dumpit() locking. xfrm: Fix potential null pointer dereference in xdst_queue_output ...
2013-08-29Merge branch 'for-3.11-fixes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup Pull cgroup fix from Tejun Heo: "During the percpu reference counting update which was merged during v3.11-rc1, the cgroup destruction path was updated so that a cgroup in the process of dying may linger on the children list, which was necessary as the cgroup should still be included in child/descendant iteration while percpu ref is being killed. Unfortunately, I forgot to update cgroup destruction path accordingly and cgroup destruction may fail spuriously with -EBUSY due to lingering dying children even when there's no live child left - e.g. "rmdir parent/child parent" will usually fail. This can be easily fixed by iterating through the children list to verify that there's no live child left. While this is very late in the release cycle, this bug is very visible to userland and I believe the fix is relatively safe. Thanks Hugh for spotting and providing fix for the issue" * 'for-3.11-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: cgroup: fix rmdir EBUSY regression in 3.11
2013-08-29cgroup: fix rmdir EBUSY regression in 3.11Hugh Dickins
On 3.11-rc we are seeing cgroup directories left behind when they should have been removed. Here's a trivial reproducer: cd /sys/fs/cgroup/memory mkdir parent parent/child; rmdir parent/child parent rmdir: failed to remove `parent': Device or resource busy It's because cgroup_destroy_locked() (step 1 of destruction) leaves cgroup on parent's children list, letting cgroup_offline_fn() (step 2 of destruction) remove it; but step 2 is run by work queue, which may not yet have removed the children when parent destruction checks the list. Fix that by checking through a non-empty list of children: if every one of them has already been marked CGRP_DEAD, then it's safe to proceed: those children are invisible to userspace, and should not obstruct rmdir. (I didn't see any reason to keep the cgrp->children checks under the unrelated css_set_lock, so moved them out.) tj: Flattened nested ifs a bit and updated comment so that it's correct on both for-3.11-fixes and for-3.12. Signed-off-by: Hugh Dickins <hughd@google.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2013-08-29workqueue: cond_resched() after processing each work itemTejun Heo
If !PREEMPT, a kworker running work items back to back can hog CPU. This becomes dangerous when a self-requeueing work item which is waiting for something to happen races against stop_machine. Such self-requeueing work item would requeue itself indefinitely hogging the kworker and CPU it's running on while stop_machine would wait for that CPU to enter stop_machine while preventing anything else from happening on all other CPUs. The two would deadlock. Jamie Liu reports that this deadlock scenario exists around scsi_requeue_run_queue() and libata port multiplier support, where one port may exclude command processing from other ports. With the right timing, scsi_requeue_run_queue() can end up requeueing itself trying to execute an IO which is asked to be retried while another device has an exclusive access, which in turn can't make forward progress due to stop_machine. Fix it by invoking cond_resched() after executing each work item. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Jamie Liu <jamieliu@google.com> References: http://thread.gmane.org/gmane.linux.kernel/1552567 Cc: stable@vger.kernel.org -- kernel/workqueue.c | 9 +++++++++ 1 file changed, 9 insertions(+)
2013-08-28timer_list: correct the iterator for timer_listNathan Zimmer
Correct an issue with /proc/timer_list reported by Holger. When reading from the proc file with a sufficiently small buffer, 2k so not really that small, there was one could get hung trying to read the file a chunk at a time. The timer_list_start function failed to account for the possibility that the offset was adjusted outside the timer_list_next. Signed-off-by: Nathan Zimmer <nzimmer@sgi.com> Reported-by: Holger Hans Peter Freyther <holger@freyther.de> Cc: John Stultz <john.stultz@linaro.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Berke Durak <berke.durak@xiphos.com> Cc: Jeff Layton <jlayton@redhat.com> Tested-by: Al Viro <viro@zeniv.linux.org.uk> Cc: <stable@vger.kernel.org> # 3.10.x Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-08-27Rename nsproxy.pid_ns to nsproxy.pid_ns_for_childrenAndy Lutomirski
nsproxy.pid_ns is *not* the task's pid namespace. The name should clarify that. This makes it more obvious that setns on a pid namespace is weird -- it won't change the pid namespace shown in procfs. Signed-off-by: Andy Lutomirski <luto@amacapital.net> Reviewed-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-08-23Merge branch 'for-3.11-fixes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup Pull cgroup fix from Tejun Heo: "A late fix for cgroup. This fixes a behavior regression visible to userland which was created by a commit merged during -rc1. While the behavior change isn't too likely to be noticeable, the fix is relatively low risk and we'll need to backport it through -stable anyway if the bug gets released" * 'for-3.11-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: cpuset: fix a regression in validating config change
2013-08-21cpuset: fix a regression in validating config changeLi Zefan
It's not allowed to clear masks of a cpuset if there're tasks in it, but it's broken: # mkdir /cgroup/sub # echo 0 > /cgroup/sub/cpuset.cpus # echo 0 > /cgroup/sub/cpuset.mems # echo $$ > /cgroup/sub/tasks # echo > /cgroup/sub/cpuset.cpus (should fail) This bug was introduced by commit 88fa523bff295f1d60244a54833480b02f775152 ("cpuset: allow to move tasks to empty cpusets"). tj: Dropped temp bool variables and nestes the conditionals directly. Signed-off-by: Li Zefan <lizefan@huawei.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2013-08-19Merge branch 'timers-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull timer fixes from Ingo Molnar: "Three small fixlets" * 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: nohz: fix compile warning in tick_nohz_init() nohz: Do not warn about unstable tsc unless user uses nohz_full sched_clock: Fix integer overflow
2013-08-19kernel: fix new kernel-doc warning in wait.cRandy Dunlap
Fix new kernel-doc warnings in kernel/wait.c: Warning(kernel/wait.c:374): No description found for parameter 'p' Warning(kernel/wait.c:374): Excess function parameter 'word' description in 'wake_up_atomic_t' Warning(kernel/wait.c:374): Excess function parameter 'bit' description in 'wake_up_atomic_t' Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: David Howells <dhowells@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-08-18Merge branch 'for-3.11-fixes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup Pull cgroup fix from Tejun Heo: "This contains one patch to fix the return value of cpuset's cgroups interface function, which used to always return -ENODEV for the writes on the 'memory_pressure_enabled' file" * 'for-3.11-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: cpuset: fix the return value of cpuset_write_u64()
2013-08-16Merge tag 'pm-3.11-rc6' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull power management fix from Rafael Wysocki: "The removal of delayed_work_pending() checks from kernel/power/qos.c done in 3.9 introduced a deadlock in pm_qos_work_fn(). Fix from Stephen Boyd" * tag 'pm-3.11-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: PM / QoS: Fix workqueue deadlock when using pm_qos_update_request_timeout()
2013-08-14Merge branch 'akpm' (patches from Andrew Morton)Linus Torvalds
Merge a bunch of fixes from Andrew Morton. * emailed patches from Andrew Morton <akpm@linux-foundation.org>: fs/proc/task_mmu.c: fix buffer overflow in add_page_map() arch: *: Kconfig: add "kernel/Kconfig.freezer" to "arch/*/Kconfig" ocfs2: fix null pointer dereference in ocfs2_dir_foreach_blk_id() x86 get_unmapped_area(): use proper mmap base for bottom-up direction ocfs2: fix NULL pointer dereference in ocfs2_duplicate_clusters_by_page ocfs2: Revert 40bd62e to avoid regression in extended allocation drivers/rtc/rtc-stmp3xxx.c: provide timeout for potentially endless loop polling a HW bit hugetlb: fix lockdep splat caused by pmd sharing aoe: adjust ref of head for compound page tails microblaze: fix clone syscall mm: save soft-dirty bits on file pages mm: save soft-dirty bits on swapped pages memcg: don't initialize kmem-cache destroying work for root caches
2013-08-13microblaze: fix clone syscallMichal Simek
Fix inadvertent breakage in the clone syscall ABI for Microblaze that was introduced in commit f3268edbe6fe ("microblaze: switch to generic fork/vfork/clone"). The Microblaze syscall ABI for clone takes the parent tid address in the 4th argument; the third argument slot is used for the stack size. The incorrectly-used CLONE_BACKWARDS type assigned parent tid to the 3rd slot. This commit restores the original ABI so that existing userspace libc code will work correctly. All kernel versions from v3.8-rc1 were affected. Signed-off-by: Michal Simek <michal.simek@xilinx.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-08-13Merge branch 'sched-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler fixes from Ingo Molnar: "Docbook fixes that make 99% of the diffstat, plus a oneliner fix" * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched: Ensure update_cfs_shares() is called for parents of continuously-running tasks sched: Fix some kernel-doc warnings
2013-08-14PM / QoS: Fix workqueue deadlock when using pm_qos_update_request_timeout()Stephen Boyd
pm_qos_update_request_timeout() updates a qos and then schedules a delayed work item to bring the qos back down to the default after the timeout. When the work item runs, pm_qos_work_fn() will call pm_qos_update_request() and deadlock because it tries to cancel itself via cancel_delayed_work_sync(). Future callers of that qos will also hang waiting to cancel the work that is canceling itself. Let's extract the little bit of code that does the real work of pm_qos_update_request() and call it from the work function so that we don't deadlock. Before ed1ac6e (PM: don't use [delayed_]work_pending()) this didn't happen because the work function wouldn't try to cancel itself. Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> Reviewed-by: Tejun Heo <tj@kernel.org> Cc: 3.9+ <stable@vger.kernel.org> # 3.9+ Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-08-13sched: fix the theoretical signal_wake_up() vs schedule() raceOleg Nesterov
This is only theoretical, but after try_to_wake_up(p) was changed to check p->state under p->pi_lock the code like __set_current_state(TASK_INTERRUPTIBLE); schedule(); can miss a signal. This is the special case of wait-for-condition, it relies on try_to_wake_up/schedule interaction and thus it does not need mb() between __set_current_state() and if(signal_pending). However, this __set_current_state() can move into the critical section protected by rq->lock, now that try_to_wake_up() takes another lock we need to ensure that it can't be reordered with "if (signal_pending(current))" check inside that section. The patch is actually one-liner, it simply adds smp_wmb() before spin_lock_irq(rq->lock). This is what try_to_wake_up() already does by the same reason. We turn this wmb() into the new helper, smp_mb__before_spinlock(), for better documentation and to allow the architectures to change the default implementation. While at it, kill smp_mb__after_lock(), it has no callers. Perhaps we can also add smp_mb__before/after_spinunlock() for prepare_to_wait(). Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-08-13cpuset: fix the return value of cpuset_write_u64()Li Zefan
Writing to this file always returns -ENODEV: # echo 1 > cpuset.memory_pressure_enabled -bash: echo: write error: No such device Signed-off-by: Li Zefan <lizefan@huawei.com> Cc: <stable@vger.kernel.org> # 3.9+ Signed-off-by: Tejun Heo <tj@kernel.org>
2013-08-12Merge branch 'core-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull w/w mutex deadlock injection fix from Ingo Molnar. This bug made the CONFIG_DEBUG_WW_MUTEX_SLOWPATH=y option largely useless, but wouldn't affect normal users. * 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: mutex: Fix w/w mutex deadlock injection
2013-08-12Merge branch 'fortglx/3.11/time' of ↵Ingo Molnar
git://git.linaro.org/people/jstultz/linux into timers/urgent Pull small fix for v3.11 from John Stultz. Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-08-08userns: limit the maximum depth of user_namespace->parent chainOleg Nesterov
Ensure that user_namespace->parent chain can't grow too much. Currently we use the hardroded 32 as limit. Reported-by: Andy Lutomirski <luto@amacapital.net> Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-08-07Merge tag 'trace-fixes-3.11-rc3' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing fixes from Steven Rostedt: "Oleg Nesterov has been working hard in closing all the holes that can lead to race conditions between deleting an event and accessing an event debugfs file. This included a fix to the debugfs system (acked by Greg Kroah-Hartman). We think that all the holes have been patched and hopefully we don't find more. I haven't marked all of them for stable because I need to examine them more to figure out how far back some of the changes need to go. Along the way, some other fixes have been made. Alexander Z Lam fixed some logic where the wrong buffer was being modifed. Andrew Vagin found a possible corruption for machines that actually allocate cpumask, as a reference to one was being zeroed out by mistake. Dhaval Giani found a bad prototype when tracing is not configured. And I not only had some changes to help Oleg, but also finally fixed a long standing bug that Dave Jones and others have been hitting, where a module unload and reload can cause the function tracing accounting to get screwed up" * tag 'trace-fixes-3.11-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: tracing: Fix reset of time stamps during trace_clock changes tracing: Make TRACE_ITER_STOP_ON_FREE stop the correct buffer tracing: Fix trace_dump_stack() proto when CONFIG_TRACING is not set tracing: Fix fields of struct trace_iterator that are zeroed by mistake tracing/uprobes: Fail to unregister if probe event files are in use tracing/kprobes: Fail to unregister if probe event files are in use tracing: Add comment to describe special break case in probe_remove_event_call() tracing: trace_remove_event_call() should fail if call/file is in use debugfs: debugfs_remove_recursive() must not rely on list_empty(d_subdirs) ftrace: Check module functions being traced on reload ftrace: Consolidate some duplicate code for updating ftrace ops tracing: Change remove_event_file_dir() to clear "d_subdirs"->i_private tracing: Introduce remove_event_file_dir() tracing: Change f_start() to take event_mutex and verify i_private != NULL tracing: Change event_filter_read/write to verify i_private != NULL tracing: Change event_enable/disable_read() to verify i_private != NULL tracing: Turn event/id->i_private into call->event.type
2013-08-06Merge branch 'for-3.11-fixes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup Pull cgroup fix from Tejun Heo: "Fix for a minor memory leak bug in the cgroup init failure path" * 'for-3.11-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: cgroup: fix a leak when percpu_ref_init() fails
2013-08-06Merge branch 'for-3.11-fixes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq Pull two workqueue fixes from Tejun Heo: "A lockdep notation update so that nested work_on_cpu() invocations don't lead to spurious lockdep warnings and fix for an unbound attr bug which made what's shown in sysfs deviate from the actual ones. Both patches have pretty limited scope" * 'for-3.11-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq: workqueue: copy workqueue_attrs with all fields workqueue: allow work_on_cpu() to be called recursively
2013-08-06printk: Fix return of braille_register_console()Steven Rostedt
Some of my configs I test with have CONFIG_A11Y_BRAILLE_CONSOLE set. When I started testing against v3.11-rc4 my console went bonkers. Using ktest to bisect the issue, it came down to: commit bbeddf52a "printk: move braille console support into separate braille.[ch] files" Looking into the patch I found the problem. It's with the return of braille_register_console(). As anything other than NULL is considered a failure. But for those of us that have CONFIG_A11Y_BRAILLE_CONSOLE set but do not define a "brl" or "brl=" on the command line, we still may want a console that those with sight can still use. Return NULL (success) if "brl" or "brl=" is not on the console line. Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Acked-by: Joe Perches <joe@perches.com> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-08-06Revert "ptrace: PTRACE_DETACH should do flush_ptrace_hw_breakpoint(child)"Oleg Nesterov
This reverts commit fab840fc2d542fabcab903db8e03589a6702ba5f. This commit even has the test-case to prove that the tracee can be killed by SIGTRAP if the debugger does not remove the breakpoints before PTRACE_DETACH. However, this is exactly what wineserver deliberately does, set_thread_context() calls PTRACE_ATTACH + PTRACE_DETACH just for PTRACE_POKEUSER(DR*) in between. So we should revert this fix and document that PTRACE_DETACH should keep the breakpoints. Reported-by: Felipe Contreras <felipe.contreras@gmail.com> Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-08-06userns: unshare_userns(&cred) should not populate cred on failureOleg Nesterov
unshare_userns(new_cred) does *new_cred = prepare_creds() before create_user_ns() which can fail. However, the caller expects that it doesn't need to take care of new_cred if unshare_userns() fails. We could change the single caller, sys_unshare(), but I think it would be more clean to avoid the side effects on failure, so with this patch unshare_userns() does put_cred() itself and initializes *new_cred only if create_user_ns() succeeeds. Cc: stable@vger.kernel.org Signed-off-by: Oleg Nesterov <oleg@redhat.com> Reviewed-by: Andy Lutomirski <luto@amacapital.net> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-08-02tracing: Fix reset of time stamps during trace_clock changesAlexander Z Lam
Fixed two issues with changing the timestamp clock with trace_clock: - The global buffer was reset on instance clock changes. Change this to pass the correct per-instance buffer - ftrace_now() is used to set buf->time_start in tracing_reset_online_cpus(). This was incorrect because ftrace_now() used the global buffer's clock to return the current time. Change this to use buffer_ftrace_now() which returns the current time for the correct per-instance buffer. Also removed tracing_reset_current() because it is not used anywhere Link: http://lkml.kernel.org/r/1375493777-17261-2-git-send-email-azl@google.com Cc: Vaibhav Nagarnaik <vnagarnaik@google.com> Cc: David Sharp <dhsharp@google.com> Cc: Alexander Z Lam <lambchop468@gmail.com> Cc: stable@vger.kernel.org # 3.10 Signed-off-by: Alexander Z Lam <azl@google.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-08-02tracing: Make TRACE_ITER_STOP_ON_FREE stop the correct bufferAlexander Z Lam
Releasing the free_buffer file in an instance causes the global buffer to be stopped when TRACE_ITER_STOP_ON_FREE is enabled. Operate on the correct buffer. Link: http://lkml.kernel.org/r/1375493777-17261-1-git-send-email-azl@google.com Cc: Vaibhav Nagarnaik <vnagarnaik@google.com> Cc: David Sharp <dhsharp@google.com> Cc: Alexander Z Lam <lambchop468@gmail.com> Cc: stable@vger.kernel.org # 3.10 Signed-off-by: Alexander Z Lam <azl@google.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-08-02tracing: Fix fields of struct trace_iterator that are zeroed by mistakeAndrew Vagin
tracing_read_pipe zeros all fields bellow "seq". The declaration contains a comment about that, but it doesn't help. The first field is "snapshot", it's true when current open file is snapshot. Looks obvious, that it should not be zeroed. The second field is "started". It was converted from cpumask_t to cpumask_var_t (v2.6.28-4983-g4462344), in other words it was converted from cpumask to pointer on cpumask. Currently the reference on "started" memory is lost after the first read from tracing_read_pipe and a proper object will never be freed. The "started" is never dereferenced for trace_pipe, because trace_pipe can't have the TRACE_FILE_ANNOTATE options. Link: http://lkml.kernel.org/r/1375463803-3085183-1-git-send-email-avagin@openvz.org Cc: stable@vger.kernel.org # 2.6.30 Signed-off-by: Andrew Vagin <avagin@openvz.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-08-02Merge tag 'pm+acpi-3.11-rc4' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull ACPI and power management fixes from Rafael Wysocki: - Revert two cpuidle commits added during the 3.8 development cycle that turn out to have introduced a significant performance regression as requested by Jeremy Eder. - The recent patches that made the freezer less heavy-weight introduced a regression causing user-space-driven hibernation using the ioctl() interface to block indefinitely when the hibernate process executes try_to_freeze(). Fix from Colin Cross addresses this by adding a process flag to mark the hibernate/suspend process to inform the freezer that that process should be ignored. - One of the recent cpufreq reverts uncovered a problem in the core causing the cpufreq driver module refcount to become negative after a system suspend-resume cycle. Fix from Rafael J Wysocki. - The evaluation of the ACPI battery _BIX method has never worked correctly, because the commit that added support for it forgot to take the "Revision" field in the return package into account. As a result, the reading of battery info doesn't work at all on some systems, which is addressed by a fix from Lan Tianyu. * tag 'pm+acpi-3.11-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: freezer: set PF_SUSPEND_TASK flag on tasks that call freeze_processes ACPI / battery: Fix parsing _BIX return value cpufreq: Fix cpufreq driver module refcount balance after suspend/resume Revert "cpuidle: Quickly notice prediction failure for repeat mode" Revert "cpuidle: Quickly notice prediction failure in general case"
2013-08-01tracing/uprobes: Fail to unregister if probe event files are in useSteven Rostedt (Red Hat)
Uprobes suffer the same problem that kprobes have. There's a race between writing to the "enable" file and removing the probe. The probe checks for it being in use and if it is not, goes about deleting the probe and the event that represents it. But the problem with that is, after it checks if it is in use it can be enabled, and the deletion of the event (access to the probe) will fail, as it is in use. But the uprobe will still be deleted. This is a problem as the event can reference the uprobe that was deleted. The fix is to remove the event first, and check to make sure the event removal succeeds. Then it is safe to remove the probe. When the event exists, either ftrace or perf can enable the probe and prevent the event from being removed. Link: http://lkml.kernel.org/r/20130704034038.991525256@goodmis.org Acked-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-08-01workqueue: copy workqueue_attrs with all fieldsShaohua Li
$echo '0' > /sys/bus/workqueue/devices/xxx/numa $cat /sys/bus/workqueue/devices/xxx/numa I got 1. It should be 0, the reason is copy_workqueue_attrs() called in apply_workqueue_attrs() doesn't copy no_numa field. Fix it by making copy_workqueue_attrs() copy ->no_numa too. This would also make get_unbound_pool() set a pool's ->no_numa attribute according to the workqueue attributes used when the pool was created. While harmelss, as ->no_numa isn't a pool attribute, this is a bit confusing. Clear it explicitly. tj: Updated description and comments a bit. Signed-off-by: Shaohua Li <shli@fusionio.com> Signed-off-by: Tejun Heo <tj@kernel.org> Cc: stable@vger.kernel.org
2013-07-31tracing/kprobes: Fail to unregister if probe event files are in useSteven Rostedt (Red Hat)
When a probe is being removed, it cleans up the event files that correspond to the probe. But there is a race between writing to one of these files and deleting the probe. This is especially true for the "enable" file. CPU 0 CPU 1 ----- ----- fd = open("enable",O_WRONLY); probes_open() release_all_trace_probes() unregister_trace_probe() if (trace_probe_is_enabled(tp)) return -EBUSY write(fd, "1", 1) __ftrace_set_clr_event() call->class->reg() (kprobe_register) enable_trace_probe(tp) __unregister_trace_probe(tp); list_del(&tp->list) unregister_probe_event(tp) <-- fails! free_trace_probe(tp) write(fd, "0", 1) __ftrace_set_clr_event() call->class->unreg (kprobe_register) disable_trace_probe(tp) <-- BOOM! A test program was written that used two threads to simulate the above scenario adding a nanosleep() interval to change the timings and after several thousand runs, it was able to trigger this bug and crash: BUG: unable to handle kernel paging request at 00000005000000f9 IP: [<ffffffff810dee70>] probes_open+0x3b/0xa7 PGD 7808a067 PUD 0 Oops: 0000 [#1] PREEMPT SMP Dumping ftrace buffer: --------------------------------- Modules linked in: ipt_MASQUERADE sunrpc ip6t_REJECT nf_conntrack_ipv6 CPU: 1 PID: 2070 Comm: test-kprobe-rem Not tainted 3.11.0-rc3-test+ #47 Hardware name: To Be Filled By O.E.M. To Be Filled By O.E.M./To be filled by O.E.M., BIOS SDBLI944.86P 05/08/2007 task: ffff880077756440 ti: ffff880076e52000 task.ti: ffff880076e52000 RIP: 0010:[<ffffffff810dee70>] [<ffffffff810dee70>] probes_open+0x3b/0xa7 RSP: 0018:ffff880076e53c38 EFLAGS: 00010203 RAX: 0000000500000001 RBX: ffff88007844f440 RCX: 0000000000000003 RDX: 0000000000000003 RSI: 0000000000000003 RDI: ffff880076e52000 RBP: ffff880076e53c58 R08: ffff880076e53bd8 R09: 0000000000000000 R10: ffff880077756440 R11: 0000000000000006 R12: ffffffff810dee35 R13: ffff880079250418 R14: 0000000000000000 R15: ffff88007844f450 FS: 00007f87a276f700(0000) GS:ffff88007d480000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b CR2: 00000005000000f9 CR3: 0000000077262000 CR4: 00000000000007e0 Stack: ffff880076e53c58 ffffffff81219ea0 ffff88007844f440 ffffffff810dee35 ffff880076e53ca8 ffffffff81130f78 ffff8800772986c0 ffff8800796f93a0 ffffffff81d1b5d8 ffff880076e53e04 0000000000000000 ffff88007844f440 Call Trace: [<ffffffff81219ea0>] ? security_file_open+0x2c/0x30 [<ffffffff810dee35>] ? unregister_trace_probe+0x4b/0x4b [<ffffffff81130f78>] do_dentry_open+0x162/0x226 [<ffffffff81131186>] finish_open+0x46/0x54 [<ffffffff8113f30b>] do_last+0x7f6/0x996 [<ffffffff8113cc6f>] ? inode_permission+0x42/0x44 [<ffffffff8113f6dd>] path_openat+0x232/0x496 [<ffffffff8113fc30>] do_filp_open+0x3a/0x8a [<ffffffff8114ab32>] ? __alloc_fd+0x168/0x17a [<ffffffff81131f4e>] do_sys_open+0x70/0x102 [<ffffffff8108f06e>] ? trace_hardirqs_on_caller+0x160/0x197 [<ffffffff81131ffe>] SyS_open+0x1e/0x20 [<ffffffff81522742>] system_call_fastpath+0x16/0x1b Code: e5 41 54 53 48 89 f3 48 83 ec 10 48 23 56 78 48 39 c2 75 6c 31 f6 48 c7 RIP [<ffffffff810dee70>] probes_open+0x3b/0xa7 RSP <ffff880076e53c38> CR2: 00000005000000f9 ---[ end trace 35f17d68fc569897 ]--- The unregister_trace_probe() must be done first, and if it fails it must fail the removal of the kprobe. Several changes have already been made by Oleg Nesterov and Masami Hiramatsu to allow moving the unregister_probe_event() before the removal of the probe and exit the function if it fails. This prevents the tp structure from being used after it is freed. Link: http://lkml.kernel.org/r/20130704034038.819592356@goodmis.org Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-07-31Merge branch 'akpm' (patches from Andrew Morton)Linus Torvalds
Merge more patches from Andrew Morton: "A bunch of fixes. Plus Joe's printk move and rework. It's not a -rc3 thing but now would be a nice time to offload it, while things are quiet. I've been sitting on it all for a couple of weeks, no issues" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: vmpressure: make sure there are no events queued after memcg is offlined vmpressure: do not check for pending work to prevent from new work vmpressure: change vmpressure::sr_lock to spinlock printk: rename struct log to struct printk_log printk: use pointer for console_cmdline indexing printk: move braille console support into separate braille.[ch] files printk: add console_cmdline.h printk: move to separate directory for easier modification drivers/rtc/rtc-twl.c: fix: rtcX/wakealarm attribute isn't created mm: zbud: fix condition check on allocation size thp, mm: avoid PageUnevictable on active/inactive lru lists mm/swap.c: clear PageActive before adding pages onto unevictable list arch/x86/platform/ce4100/ce4100.c: include reboot.h mm: sched: numa: fix NUMA balancing when !SCHED_DEBUG rapidio: fix use after free in rio_unregister_scan() .gitignore: ignore *.lz4 files MAINTAINERS: dynamic debug: Jason's not there... dmi_scan: add comments on dmi_present() and the loop in dmi_scan_machine() ocfs2/refcounttree: add the missing NULL check of the return value of find_or_create_page() mm: mempolicy: fix mbind_range() && vma_adjust() interaction
2013-07-31printk: rename struct log to struct printk_logJoe Perches
Rename the struct to enable moving portions of printk.c to separate files. The rename changes output of /proc/vmcoreinfo. Signed-off-by: Joe Perches <joe@perches.com> Cc: Samuel Thibault <samuel.thibault@ens-lyon.org> Cc: Ming Lei <ming.lei@canonical.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-31printk: use pointer for console_cmdline indexingJoe Perches
Make the code a bit more compact by always using a pointer for the active console_cmdline. Move overly indented code to correct indent level. Signed-off-by: Joe Perches <joe@perches.com> Cc: Samuel Thibault <samuel.thibault@ens-lyon.org> Cc: Ming Lei <ming.lei@canonical.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-31printk: move braille console support into separate braille.[ch] filesJoe Perches
Create files with prototypes and static inlines for braille support. Make braille_console functions return 1 on success. Corrected CONFIG_A11Y_BRAILLE_CONSOLE=n _braille_console_setup return value to NULL. Signed-off-by: Joe Perches <joe@perches.com> Reviewed-by: Samuel Thibault <samuel.thibault@ens-lyon.org> Cc: Ming Lei <ming.lei@canonical.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-31printk: add console_cmdline.hJoe Perches
Add an include file for the console_cmdline struct so that the braille console driver can be separated. Signed-off-by: Joe Perches <joe@perches.com> Cc: Samuel Thibault <samuel.thibault@ens-lyon.org> Cc: Ming Lei <ming.lei@canonical.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>