user/sven/linux.git/kernel, branch v3.18.67

pids: make task_tgid_nr_ns() safe

2017-08-25T00:00:10Z

commit dd1c1f2f2028a7b851f701fc6a8ebe39dcb95e7c upstream. This was reported many times, and this was even mentioned in commit 52ee2dfdd4f5 ("pids: refactor vnr/nr_ns helpers to make them safe") but somehow nobody bothered to fix the obvious problem: task_tgid_nr_ns() is not safe because task->group_leader points to nowhere after the exiting task passes exit_notify(), rcu_read_lock() can not help. We really need to change __unhash_process() to nullify group_leader, parent, and real_parent, but this needs some cleanups. Until then we can turn task_tgid_nr_ns() into another user of __task_pid_nr_ns() and fix the problem. Reported-by: Troy Kensinger Signed-off-by: Oleg Nesterov Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

audit: Fix use after free in audit_remove_watch_rule()

2017-08-25T00:00:10Z

commit d76036ab47eafa6ce52b69482e91ca3ba337d6d6 upstream. audit_remove_watch_rule() drops watch's reference to parent but then continues to work with it. That is not safe as parent can get freed once we drop our reference. The following is a trivial reproducer: mount -o loop image /mnt touch /mnt/file auditctl -w /mnt/file -p wax umount /mnt auditctl -D Grab our own reference in audit_remove_watch_rule() earlier to make sure mark does not get freed under us. Reported-by: Tony Jones Signed-off-by: Jan Kara Tested-by: Tony Jones Signed-off-by: Paul Moore Signed-off-by: Greg Kroah-Hartman

workqueue: implicit ordered attribute should be overridable

2017-08-11T16:30:16Z

commit 0a94efb5acbb6980d7c9ab604372d93cd507e4d8 upstream. 5c0338c68706 ("workqueue: restore WQ_UNBOUND/max_active==1 to be ordered") automatically enabled ordered attribute for unbound workqueues w/ max_active == 1. Because ordered workqueues reject max_active and some attribute changes, this implicit ordered mode broke cases where the user creates an unbound workqueue w/ max_active == 1 and later explicitly changes the related attributes. This patch distinguishes explicit and implicit ordered setting and overrides from attribute changes if implict. Signed-off-by: Tejun Heo Fixes: 5c0338c68706 ("workqueue: restore WQ_UNBOUND/max_active==1 to be ordered") Cc: Holger Hoffstätte Signed-off-by: Greg Kroah-Hartman

signal: protect SIGNAL_UNKILLABLE from unintentional clearing.

2017-08-11T16:30:16Z

[ Upstream commit 2d39b3cd34e6d323720d4c61bd714f5ae202c022 ] Since commit 00cd5c37afd5 ("ptrace: permit ptracing of /sbin/init") we can now trace init processes. init is initially protected with SIGNAL_UNKILLABLE which will prevent fatal signals such as SIGSTOP, but there are a number of paths during tracing where SIGNAL_UNKILLABLE can be implicitly cleared. This can result in init becoming stoppable/killable after tracing. For example, running: while true; do kill -STOP 1; done & strace -p 1 and then stopping strace and the kill loop will result in init being left in state TASK_STOPPED. Sending SIGCONT to init will resume it, but init will now respond to future SIGSTOP signals rather than ignoring them. Make sure that when setting SIGNAL_STOP_CONTINUED/SIGNAL_STOP_STOPPED that we don't clear SIGNAL_UNKILLABLE. Link: http://lkml.kernel.org/r/20170104122017.25047-1-jamie.iles@oracle.com Signed-off-by: Jamie Iles Acked-by: Oleg Nesterov Cc: Alexander Viro Cc: Ingo Molnar Cc: Peter Zijlstra Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

workqueue: restore WQ_UNBOUND/max_active==1 to be ordered

2017-08-11T16:30:13Z

commit 5c0338c68706be53b3dc472e4308961c36e4ece1 upstream. The combination of WQ_UNBOUND and max_active == 1 used to imply ordered execution. After NUMA affinity 4c16bd327c74 ("workqueue: implement NUMA affinity for unbound workqueues"), this is no longer true due to per-node worker pools. While the right way to create an ordered workqueue is alloc_ordered_workqueue(), the documentation has been misleading for a long time and people do use WQ_UNBOUND and max_active == 1 for ordered workqueues which can lead to subtle bugs which are very difficult to trigger. It's unlikely that we'd see noticeable performance impact by enforcing ordering on WQ_UNBOUND / max_active == 1 workqueues. Let's automatically set __WQ_ORDERED for those workqueues. Signed-off-by: Tejun Heo Reported-by: Christoph Hellwig Reported-by: Alexei Potashnik Fixes: 4c16bd327c74 ("workqueue: implement NUMA affinity for unbound workqueues") Signed-off-by: Greg Kroah-Hartman

alarmtimer: don't rate limit one-shot timers

2017-07-27T22:03:29Z

Commit ff86bf0c65f1 ("alarmtimer: Rate limit periodic intervals") sets a minimum bound on the alarm timer interval. This minimum bound shouldn't be applied if the interval is 0. Otherwise, one-shot timers will be converted into periodic ones. Fixes: ff86bf0c65f1 ("alarmtimer: Rate limit periodic intervals") Reported-by: Ben Fennema Signed-off-by: Greg Hackmann Cc: stable@vger.kernel.org Cc: John Stultz Reviewed-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman

tracing: Fix kmemleak in instance_rmdir

2017-07-27T22:03:29Z

commit db9108e054700c96322b0f0028546aa4e643cf0b upstream. Hit the kmemleak when executing instance_rmdir, it forgot releasing mem of tracing_cpumask. With this fix, the warn does not appear any more. unreferenced object 0xffff93a8dfaa7c18 (size 8): comm "mkdir", pid 1436, jiffies 4294763622 (age 9134.308s) hex dump (first 8 bytes): ff ff ff ff ff ff ff ff ........ backtrace: [] kmemleak_alloc+0x4a/0xa0 [] __kmalloc_node+0xf1/0x280 [] alloc_cpumask_var_node+0x23/0x30 [] alloc_cpumask_var+0xe/0x10 [] instance_mkdir+0x90/0x240 [] tracefs_syscall_mkdir+0x40/0x70 [] vfs_mkdir+0x109/0x1b0 [] SyS_mkdir+0xd0/0x100 [] do_syscall_64+0x67/0x150 [] return_from_SYSCALL_64+0x0/0x6a [] 0xffffffffffffffff Link: http://lkml.kernel.org/r/1500546969-12594-1-git-send-email-chuhu@redhat.com Fixes: ccfe9e42e451 ("tracing: Make tracing_cpumask available for all instances") Signed-off-by: Chunyu Hu Signed-off-by: Steven Rostedt (VMware) Signed-off-by: Greg Kroah-Hartman

Revert "perf/core: Drop kernel samples even though :u is specified"

2017-07-27T22:03:28Z

commit 6a8a75f3235724c5941a33e287b2f98966ad14c5 upstream. This reverts commit cc1582c231ea041fbc68861dfaf957eaf902b829. This commit introduced a regression that broke rr-project, which uses sampling events to receive a signal on overflow (but does not care about the contents of the sample). These signals are critical to the correct operation of rr. There's been some back and forth about how to fix it - but to not keep applications in limbo queue up a revert. Reported-by: Kyle Huey Acked-by: Kyle Huey Acked-by: Peter Zijlstra Cc: Jin Yao Cc: Vince Weaver Cc: Linus Torvalds Cc: Will Deacon Cc: Arnaldo Carvalho de Melo Cc: Alexander Shishkin Cc: Stephane Eranian Cc: Namhyung Kim Cc: Jiri Olsa Link: http://lkml.kernel.org/r/20170628105600.GC5981@leverpostej Signed-off-by: Ingo Molnar Signed-off-by: Greg Kroah-Hartman

tracing: Use SOFTIRQ_OFFSET for softirq dectection for more accurate results

2017-07-21T06:12:23Z

commit c59f29cb144a6a0dfac16ede9dc8eafc02dc56ca upstream. The 's' flag is supposed to indicate that a softirq is running. This can be detected by testing the preempt_count with SOFTIRQ_OFFSET. The current code tests the preempt_count with SOFTIRQ_MASK, which would be true even when softirqs are disabled but not serving a softirq. Link: http://lkml.kernel.org/r/1481300417-3564-1-git-send-email-pkondeti@codeaurora.org Signed-off-by: Pavankumar Kondeti Signed-off-by: Steven Rostedt Signed-off-by: Amit Pundir Signed-off-by: Greg Kroah-Hartman

sched/topology: Fix overlapping sched_group_mask

2017-07-21T06:12:23Z

commit 73bb059f9b8a00c5e1bf2f7ca83138c05d05e600 upstream. The point of sched_group_mask is to select those CPUs from sched_group_cpus that can actually arrive at this balance domain. The current code gets it wrong, as can be readily demonstrated with a topology like: node 0 1 2 3 0: 10 20 30 20 1: 20 10 20 30 2: 30 20 10 20 3: 20 30 20 10 Where (for example) domain 1 on CPU1 ends up with a mask that includes CPU0: [] CPU1 attaching sched-domain: [] domain 0: span 0-2 level NUMA [] groups: 1 (mask: 1), 2, 0 [] domain 1: span 0-3 level NUMA [] groups: 0-2 (mask: 0-2) (cpu_capacity: 3072), 0,2-3 (cpu_capacity: 3072) This causes sched_balance_cpu() to compute the wrong CPU and consequently should_we_balance() will terminate early resulting in missed load-balance opportunities. The fixed topology looks like: [] CPU1 attaching sched-domain: [] domain 0: span 0-2 level NUMA [] groups: 1 (mask: 1), 2, 0 [] domain 1: span 0-3 level NUMA [] groups: 0-2 (mask: 1) (cpu_capacity: 3072), 0,2-3 (cpu_capacity: 3072) (note: this relies on OVERLAP domains to always have children, this is true because the regular topology domains are still here -- this is before degenerate trimming) Debugged-by: Lauro Ramos Venancio Signed-off-by: Peter Zijlstra (Intel) Cc: Linus Torvalds Cc: Mike Galbraith Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-kernel@vger.kernel.org Fixes: e3589f6c81e4 ("sched: Allow for overlapping sched_domain spans") Signed-off-by: Ingo Molnar Signed-off-by: Greg Kroah-Hartman