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2017-06-18Merge branch 'timers-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull timer fixes from Thomas Gleixner: "Three fixlets for timers: - Two hot-fixes for the alarmtimer based posix timers, which prevent a nasty DOS by self rescheduling timers. The proper cleanup of that mess is queued for 4.13 - Make a function static" * 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: tick/broadcast: Make tick_broadcast_setup_oneshot() static alarmtimer: Rate limit periodic intervals alarmtimer: Prevent overflow of relative timers
2017-06-18Merge branch 'sched-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler fixes from Thomas Gleixner: "Two small fixes for the schedulre core: - Use the proper switch_mm() variant in idle_task_exit() because that code is not called with interrupts disabled. - Fix a confusing typo in a printk" * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/core: Idle_task_exit() shouldn't use switch_mm_irqs_off() sched/fair: Fix typo in printk message
2017-06-18Merge branch 'irq-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull irq fix from Thomas Gleixner: "Add a missing resource release to an error path" * 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: genirq: Release resources in __setup_irq() error path
2017-06-15Merge branches 'pm-cpufreq', 'pm-cpuidle' and 'pm-devfreq'Rafael J. Wysocki
* pm-cpufreq: cpufreq: conservative: Allow down_threshold to take values from 1 to 10 Revert "cpufreq: schedutil: Reduce frequencies slower" * pm-cpuidle: cpuidle: dt: Add missing 'of_node_put()' * pm-devfreq: PM / devfreq: exynos-ppmu: Staticize event list PM / devfreq: exynos-ppmu: Handle return value of clk_prepare_enable PM / devfreq: exynos-nocp: Handle return value of clk_prepare_enable
2017-06-13genirq: Release resources in __setup_irq() error pathHeiner Kallweit
In case __irq_set_trigger() fails the resources requested via irq_request_resources() are not released. Add the missing release call into the error handling path. Fixes: c1bacbae8192 ("genirq: Provide irq_request/release_resources chip callbacks") Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/655538f5-cb20-a892-ff15-fbd2dd1fa4ec@gmail.com
2017-06-12tick/broadcast: Make tick_broadcast_setup_oneshot() staticStephen Boyd
This function isn't used outside of tick-broadcast.c, so let's mark it static. Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> Link: http://lkml.kernel.org/r/20170608063603.13276-1-sboyd@codeaurora.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2017-06-12Revert "cpufreq: schedutil: Reduce frequencies slower"Rafael J. Wysocki
Revert commit 39b64aa1c007 (cpufreq: schedutil: Reduce frequencies slower) that introduced unintentional changes in behavior leading to adverse effects on some systems. Reported-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2017-06-11sched/core: Idle_task_exit() shouldn't use switch_mm_irqs_off()Andy Lutomirski
idle_task_exit() can be called with IRQs on x86 on and therefore should use switch_mm(), not switch_mm_irqs_off(). This doesn't seem to cause any problems right now, but it will confuse my upcoming TLB flush changes. Nonetheless, I think it should be backported because it's trivial. There won't be any meaningful performance impact because idle_task_exit() is only used when offlining a CPU. Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@suse.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org Fixes: f98db6013c55 ("sched/core: Add switch_mm_irqs_off() and use it in the scheduler") Link: http://lkml.kernel.org/r/ca3d1a9fa93a0b49f5a8ff729eda3640fb6abdf9.1497034141.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-06-11sched/fair: Fix typo in printk messageMarcin Nowakowski
'schedstats' kernel parameter should be set to enable/disable, so correct the printk hint saying that it should be set to 'enable' rather than 'enabled' to enable scheduler tracepoints. Signed-off-by: Marcin Nowakowski <marcin.nowakowski@imgtec.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1496995229-31245-1-git-send-email-marcin.nowakowski@imgtec.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-06-10Merge branch 'smp-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull CPU hotplug fix from Ingo Molnar: "An error handling corner case fix" * 'smp-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: cpu/hotplug: Drop the device lock on error
2017-06-10Merge branch 'rcu-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull RCU fixes from Ingo Molnar: "Fix an SRCU bug affecting KVM IRQ injection" * 'rcu-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: srcu: Allow use of Classic SRCU from both process and interrupt context srcu: Allow use of Tiny/Tree SRCU from both process and interrupt context
2017-06-10Merge branch 'perf-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf fixes from Ingo Molnar: "This is mostly tooling fixes, plus an instruction pointer filtering fix. It's more fixes than usual - Arnaldo got back from a longer vacation and there was a backlog" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (27 commits) perf symbols: Kill dso__build_id_is_kmod() perf symbols: Keep DSO->symtab_type after decompress perf tests: Decompress kernel module before objdump perf tools: Consolidate error path in __open_dso() perf tools: Decompress kernel module when reading DSO data perf annotate: Use dso__decompress_kmodule_path() perf tools: Introduce dso__decompress_kmodule_{fd,path} perf tools: Fix a memory leak in __open_dso() perf annotate: Fix symbolic link of build-id cache perf/core: Drop kernel samples even though :u is specified perf script python: Remove dups in documentation examples perf script python: Updated trace_unhandled() signature perf script python: Fix wrong code snippets in documentation perf script: Fix documentation errors perf script: Fix outdated comment for perf-trace-python perf probe: Fix examples section of documentation perf report: Ensure the perf DSO mapping matches what libdw sees perf report: Include partial stacks unwound with libdw perf annotate: Add missing powerpc triplet perf test: Disable breakpoint signal tests for powerpc ...
2017-06-09Merge branch 'rcu/urgent' of ↵Ingo Molnar
git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into rcu/urgent Pull RCU fix from Paul E. McKenney: " This series enables srcu_read_lock() and srcu_read_unlock() to be used from interrupt handlers, which fixes a bug in KVM's use of SRCU in delivery of interrupts to guest OSes. " Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-06-08Merge tag 'pm-4.12-rc5' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull power management fixes from Rafael Wysocki: "These revert one problematic commit related to system sleep and fix one recent intel_pstate regression. Specifics: - Revert a recent commit that attempted to avoid spurious wakeups from suspend-to-idle via ACPI SCI, but introduced regressions on some systems (Rafael Wysocki). We will get back to the problem it tried to address in the next cycle. - Fix a possible division by 0 during intel_pstate initialization due to a missing check (Rafael Wysocki)" * tag 'pm-4.12-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: Revert "ACPI / sleep: Ignore spurious SCI wakeups from suspend-to-idle" cpufreq: intel_pstate: Avoid division by 0 in min_perf_pct_min()
2017-06-09Merge branches 'intel_pstate' and 'pm-sleep'Rafael J. Wysocki
* intel_pstate: cpufreq: intel_pstate: Avoid division by 0 in min_perf_pct_min() * pm-sleep: Revert "ACPI / sleep: Ignore spurious SCI wakeups from suspend-to-idle"
2017-06-08Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk Pull printk fix from Petr Mladek: "This reverts a fix added into 4.12-rc1. It caused the kernel log to be printed on another console when two consoles of the same type were defined, e.g. console=ttyS0 console=ttyS1. This configuration was never supported by kernel itself, but it started to make sense with systemd. In other words, the commit broke userspace" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk: Revert "printk: fix double printing with earlycon"
2017-06-08srcu: Allow use of Classic SRCU from both process and interrupt contextPaolo Bonzini
Linu Cherian reported a WARN in cleanup_srcu_struct() when shutting down a guest running iperf on a VFIO assigned device. This happens because irqfd_wakeup() calls srcu_read_lock(&kvm->irq_srcu) in interrupt context, while a worker thread does the same inside kvm_set_irq(). If the interrupt happens while the worker thread is executing __srcu_read_lock(), updates to the Classic SRCU ->lock_count[] field or the Tree SRCU ->srcu_lock_count[] field can be lost. The docs say you are not supposed to call srcu_read_lock() and srcu_read_unlock() from irq context, but KVM interrupt injection happens from (host) interrupt context and it would be nice if SRCU supported the use case. KVM is using SRCU here not really for the "sleepable" part, but rather due to its IPI-free fast detection of grace periods. It is therefore not desirable to switch back to RCU, which would effectively revert commit 719d93cd5f5c ("kvm/irqchip: Speed up KVM_SET_GSI_ROUTING", 2014-01-16). However, the docs are overly conservative. You can have an SRCU instance only has users in irq context, and you can mix process and irq context as long as process context users disable interrupts. In addition, __srcu_read_unlock() actually uses this_cpu_dec() on both Tree SRCU and Classic SRCU. For those two implementations, only srcu_read_lock() is unsafe. When Classic SRCU's __srcu_read_unlock() was changed to use this_cpu_dec(), in commit 5a41344a3d83 ("srcu: Simplify __srcu_read_unlock() via this_cpu_dec()", 2012-11-29), __srcu_read_lock() did two increments. Therefore it kept __this_cpu_inc(), with preempt_disable/enable in the caller. Tree SRCU however only does one increment, so on most architectures it is more efficient for __srcu_read_lock() to use this_cpu_inc(), and any performance differences appear to be down in the noise. Cc: stable@vger.kernel.org Fixes: 719d93cd5f5c ("kvm/irqchip: Speed up KVM_SET_GSI_ROUTING") Reported-by: Linu Cherian <linuc.decode@gmail.com> Suggested-by: Linu Cherian <linuc.decode@gmail.com> Cc: kvm@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2017-06-08srcu: Allow use of Tiny/Tree SRCU from both process and interrupt contextPaolo Bonzini
Linu Cherian reported a WARN in cleanup_srcu_struct() when shutting down a guest running iperf on a VFIO assigned device. This happens because irqfd_wakeup() calls srcu_read_lock(&kvm->irq_srcu) in interrupt context, while a worker thread does the same inside kvm_set_irq(). If the interrupt happens while the worker thread is executing __srcu_read_lock(), updates to the Classic SRCU ->lock_count[] field or the Tree SRCU ->srcu_lock_count[] field can be lost. The docs say you are not supposed to call srcu_read_lock() and srcu_read_unlock() from irq context, but KVM interrupt injection happens from (host) interrupt context and it would be nice if SRCU supported the use case. KVM is using SRCU here not really for the "sleepable" part, but rather due to its IPI-free fast detection of grace periods. It is therefore not desirable to switch back to RCU, which would effectively revert commit 719d93cd5f5c ("kvm/irqchip: Speed up KVM_SET_GSI_ROUTING", 2014-01-16). However, the docs are overly conservative. You can have an SRCU instance only has users in irq context, and you can mix process and irq context as long as process context users disable interrupts. In addition, __srcu_read_unlock() actually uses this_cpu_dec() on both Tree SRCU and Classic SRCU. For those two implementations, only srcu_read_lock() is unsafe. When Classic SRCU's __srcu_read_unlock() was changed to use this_cpu_dec(), in commit 5a41344a3d83 ("srcu: Simplify __srcu_read_unlock() via this_cpu_dec()", 2012-11-29), __srcu_read_lock() did two increments. Therefore it kept __this_cpu_inc(), with preempt_disable/enable in the caller. Tree SRCU however only does one increment, so on most architectures it is more efficient for __srcu_read_lock() to use this_cpu_inc(), and any performance differences appear to be down in the noise. Unlike Classic and Tree SRCU, Tiny SRCU does increments and decrements on a single variable. Therefore, as Peter Zijlstra pointed out, Tiny SRCU's implementation already supports mixed-context use of srcu_read_lock() and srcu_read_unlock(), at least as long as uses of srcu_read_lock() and srcu_read_unlock() in each handler are nested and paired properly. In other words, it is still illegal to (say) invoke srcu_read_lock() in an interrupt handler and to invoke the matching srcu_read_unlock() in a softirq handler. Therefore, the only change required for Tiny SRCU is to its comments. Fixes: 719d93cd5f5c ("kvm/irqchip: Speed up KVM_SET_GSI_ROUTING") Reported-by: Linu Cherian <linuc.decode@gmail.com> Suggested-by: Linu Cherian <linuc.decode@gmail.com> Cc: kvm@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Tested-by: Paolo Bonzini <pbonzini@redhat.com>
2017-06-08Revert "printk: fix double printing with earlycon"Petr Mladek
This reverts commit cf39bf58afdaabc0b86f141630fb3fd18190294e. The commit regression to users that define both console=ttyS1 and console=ttyS0 on the command line, see https://lkml.kernel.org/r/20170509082915.GA13236@bistromath.localdomain The kernel log messages always appeared only on one serial port. It is even documented in Documentation/admin-guide/serial-console.rst: "Note that you can only define one console per device type (serial, video)." The above mentioned commit changed the order in which the command line parameters are searched. As a result, the kernel log messages go to the last mentioned ttyS* instead of the first one. We long thought that using two console=ttyS* on the command line did not make sense. But then we realized that console= parameters were handled also by systemd, see http://0pointer.de/blog/projects/serial-console.html "By default systemd will instantiate one serial-getty@.service on the main kernel console, if it is not a virtual terminal." where "[4] If multiple kernel consoles are used simultaneously, the main console is the one listed first in /sys/class/tty/console/active, which is the last one listed on the kernel command line." This puts the original report into another light. The system is running in qemu. The first serial port is used to store the messages into a file. The second one is used to login to the system via a socket. It depends on systemd and the historic kernel behavior. By other words, systemd causes that it makes sense to define both console=ttyS1 console=ttyS0 on the command line. The kernel fix caused regression related to userspace (systemd) and need to be reverted. In addition, it went out that the fix helped only partially. The messages still were duplicated when the boot console was removed early by late_initcall(printk_late_init). Then the entire log was replayed when the same console was registered as a normal one. Link: 20170606160339.GC7604@pathway.suse.cz Cc: Aleksey Makarov <aleksey.makarov@linaro.org> Cc: Sabrina Dubroca <sd@queasysnail.net> Cc: Sudeep Holla <sudeep.holla@arm.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Peter Hurley <peter@hurleysoftware.com> Cc: Jiri Slaby <jslaby@suse.com> Cc: Robin Murphy <robin.murphy@arm.com>, Cc: Steven Rostedt <rostedt@goodmis.org> Cc: "Nair, Jayachandran" <Jayachandran.Nair@cavium.com> Cc: linux-serial@vger.kernel.org Cc: linux-kernel@vger.kernel.org Reported-by: Sabrina Dubroca <sd@queasysnail.net> Acked-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
2017-06-08perf/core: Drop kernel samples even though :u is specifiedJin Yao
When doing sampling, for example: perf record -e cycles:u ... On workloads that do a lot of kernel entry/exits we see kernel samples, even though :u is specified. This is due to skid existing. This might be a security issue because it can leak kernel addresses even though kernel sampling support is disabled. The patch drops the kernel samples if exclude_kernel is specified. For example, test on Haswell desktop: perf record -e cycles:u <mgen> perf report --stdio Before patch applied: 99.77% mgen mgen [.] buf_read 0.20% mgen mgen [.] rand_buf_init 0.01% mgen [kernel.vmlinux] [k] apic_timer_interrupt 0.00% mgen mgen [.] last_free_elem 0.00% mgen libc-2.23.so [.] __random_r 0.00% mgen libc-2.23.so [.] _int_malloc 0.00% mgen mgen [.] rand_array_init 0.00% mgen [kernel.vmlinux] [k] page_fault 0.00% mgen libc-2.23.so [.] __random 0.00% mgen libc-2.23.so [.] __strcasestr 0.00% mgen ld-2.23.so [.] strcmp 0.00% mgen ld-2.23.so [.] _dl_start 0.00% mgen libc-2.23.so [.] sched_setaffinity@@GLIBC_2.3.4 0.00% mgen ld-2.23.so [.] _start We can see kernel symbols apic_timer_interrupt and page_fault. After patch applied: 99.79% mgen mgen [.] buf_read 0.19% mgen mgen [.] rand_buf_init 0.00% mgen libc-2.23.so [.] __random_r 0.00% mgen mgen [.] rand_array_init 0.00% mgen mgen [.] last_free_elem 0.00% mgen libc-2.23.so [.] vfprintf 0.00% mgen libc-2.23.so [.] rand 0.00% mgen libc-2.23.so [.] __random 0.00% mgen libc-2.23.so [.] _int_malloc 0.00% mgen libc-2.23.so [.] _IO_doallocbuf 0.00% mgen ld-2.23.so [.] do_lookup_x 0.00% mgen ld-2.23.so [.] open_verify.constprop.7 0.00% mgen ld-2.23.so [.] _dl_important_hwcaps 0.00% mgen libc-2.23.so [.] sched_setaffinity@@GLIBC_2.3.4 0.00% mgen ld-2.23.so [.] _start There are only userspace symbols. Signed-off-by: Jin Yao <yao.jin@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: <stable@vger.kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: acme@kernel.org Cc: jolsa@kernel.org Cc: kan.liang@intel.com Cc: mark.rutland@arm.com Cc: will.deacon@arm.com Cc: yao.jin@intel.com Link: http://lkml.kernel.org/r/1495706947-3744-1-git-send-email-yao.jin@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-06-07Revert "ACPI / sleep: Ignore spurious SCI wakeups from suspend-to-idle"Rafael J. Wysocki
Revert commit eed4d47efe95 (ACPI / sleep: Ignore spurious SCI wakeups from suspend-to-idle) as it turned out to be premature and triggered a number of different issues on various systems. That includes, but is not limited to, premature suspend-to-RAM aborts on Dell XPS 13 (9343) reported by Dominik. The issue the commit in question attempted to address is real and will need to be taken care of going forward, but evidently more work is needed for this purpose. Reported-by: Dominik Brodowski <linux@dominikbrodowski.net> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2017-06-05Merge branch 'for-4.12-fixes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup Pull cgroup fixes from Tejun Heo: "Two cgroup fixes. One to address RCU delay of cpuset removal affecting userland visible behaviors. The other fixes a race condition between controller disable and cgroup removal" * 'for-4.12-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: cpuset: consider dying css as offline cgroup: Prevent kill_css() from being called more than once
2017-06-04alarmtimer: Rate limit periodic intervalsThomas Gleixner
The alarmtimer code has another source of potentially rearming itself too fast. Interval timers with a very samll interval have a similar CPU hog effect as the previously fixed overflow issue. The reason is that alarmtimers do not implement the normal protection against this kind of problem which the other posix timer use: timer expires -> queue signal -> deliver signal -> rearm timer This scheme brings the rearming under scheduler control and prevents permanently firing timers which hog the CPU. Bringing this scheme to the alarm timer code is a major overhaul because it lacks all the necessary mechanisms completely. So for a quick fix limit the interval to one jiffie. This is not problematic in practice as alarmtimers are usually backed by an RTC for suspend which have 1 second resolution. It could be therefor argued that the resolution of this clock should be set to 1 second in general, but that's outside the scope of this fix. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Kostya Serebryany <kcc@google.com> Cc: syzkaller <syzkaller@googlegroups.com> Cc: John Stultz <john.stultz@linaro.org> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/20170530211655.896767100@linutronix.de
2017-06-04alarmtimer: Prevent overflow of relative timersThomas Gleixner
Andrey reported a alartimer related RCU stall while fuzzing the kernel with syzkaller. The reason for this is an overflow in ktime_add() which brings the resulting time into negative space and causes immediate expiry of the timer. The following rearm with a small interval does not bring the timer back into positive space due to the same issue. This results in a permanent firing alarmtimer which hogs the CPU. Use ktime_add_safe() instead which detects the overflow and clamps the result to KTIME_SEC_MAX. Reported-by: Andrey Konovalov <andreyknvl@google.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Kostya Serebryany <kcc@google.com> Cc: syzkaller <syzkaller@googlegroups.com> Cc: John Stultz <john.stultz@linaro.org> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/20170530211655.802921648@linutronix.de
2017-06-03cpu/hotplug: Drop the device lock on errorSebastian Andrzej Siewior
If a custom CPU target is specified and that one is not available _or_ can't be interrupted then the code returns to userland without dropping a lock as notices by lockdep: |echo 133 > /sys/devices/system/cpu/cpu7/hotplug/target | ================================================ | [ BUG: lock held when returning to user space! ] | ------------------------------------------------ | bash/503 is leaving the kernel with locks still held! | 1 lock held by bash/503: | #0: (device_hotplug_lock){+.+...}, at: [<ffffffff815b5650>] lock_device_hotplug_sysfs+0x10/0x40 So release the lock then. Fixes: 757c989b9994 ("cpu/hotplug: Make target state writeable") Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/20170602142714.3ogo25f2wbq6fjpj@linutronix.de
2017-06-02Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jikos/livepatching Pull livepatching fix from Jiri Kosina: "Kconfig dependency fix for livepatching infrastructure from Miroslav Benes" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/livepatching: livepatch: Make livepatch dependent on !TRIM_UNUSED_KSYMS
2017-05-27Merge branch 'timers-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull timer fixlet from Thomas Gleixner: "Silence dmesg spam by making the posix cpu timer printks depend on print_fatal_signals" * 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: posix-timers: Make signal printks conditional
2017-05-27Merge branch 'locking-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull locking fix from Thomas Gleixner: "A fix for a state leak which was introduced in the recent rework of futex/rtmutex interaction" * 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: futex,rt_mutex: Fix rt_mutex_cleanup_proxy_lock()
2017-05-27Merge branch 'core-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull kthread fix from Thomas Gleixner: "A single fix which prevents a use after free when kthread fork fails" * 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: kthread: Fix use-after-free if kthread fork fails
2017-05-27Merge tag 'trace-v4.12-rc2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull ftrace fixes from Steven Rostedt: "There's been a few memory issues found with ftrace. One was simply a memory leak where not all was being freed that should have been in releasing a file pointer on set_graph_function. Then Thomas found that the ftrace trampolines were marked for read/write as well as execute. To shrink the possible attack surface, he added calls to set them to ro. Which also uncovered some other issues with freeing module allocated memory that had its permissions changed. Kprobes had a similar issue which is fixed and a selftest was added to trigger that issue again" * tag 'trace-v4.12-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: x86/ftrace: Make sure that ftrace trampolines are not RWX x86/mm/ftrace: Do not bug in early boot on irqs_disabled in cpu_flush_range() selftests/ftrace: Add a testcase for many kprobe events kprobes/x86: Fix to set RWX bits correctly before releasing trampoline ftrace: Fix memory leak in ftrace_graph_release()
2017-05-26kprobes/x86: Fix to set RWX bits correctly before releasing trampolineMasami Hiramatsu
Fix kprobes to set(recover) RWX bits correctly on trampoline buffer before releasing it. Releasing readonly page to module_memfree() crash the kernel. Without this fix, if kprobes user register a bunch of kprobes in function body (since kprobes on function entry usually use ftrace) and unregister it, kernel hits a BUG and crash. Link: http://lkml.kernel.org/r/149570868652.3518.14120169373590420503.stgit@devbox Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Fixes: d0381c81c2f7 ("kprobes/x86: Set kprobes pages read-only") Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-05-26ftrace: Fix memory leak in ftrace_graph_release()Luis Henriques
ftrace_hash is being kfree'ed in ftrace_graph_release(), however the ->buckets field is not. This results in a memory leak that is easily captured by kmemleak: unreferenced object 0xffff880038afe000 (size 8192): comm "trace-cmd", pid 238, jiffies 4294916898 (age 9.736s) hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace: [<ffffffff815f561e>] kmemleak_alloc+0x4e/0xb0 [<ffffffff8113964d>] __kmalloc+0x12d/0x1a0 [<ffffffff810bf6d1>] alloc_ftrace_hash+0x51/0x80 [<ffffffff810c0523>] __ftrace_graph_open.isra.39.constprop.46+0xa3/0x100 [<ffffffff810c05e8>] ftrace_graph_open+0x68/0xa0 [<ffffffff8114003d>] do_dentry_open.isra.1+0x1bd/0x2d0 [<ffffffff81140df7>] vfs_open+0x47/0x60 [<ffffffff81150f95>] path_openat+0x2a5/0x1020 [<ffffffff81152d6a>] do_filp_open+0x8a/0xf0 [<ffffffff811411df>] do_sys_open+0x12f/0x200 [<ffffffff811412ce>] SyS_open+0x1e/0x20 [<ffffffff815fa6e0>] entry_SYSCALL_64_fastpath+0x13/0x94 [<ffffffffffffffff>] 0xffffffffffffffff Link: http://lkml.kernel.org/r/20170525152038.7661-1-lhenriques@suse.com Cc: stable@vger.kernel.org Fixes: b9b0c831bed2 ("ftrace: Convert graph filter to use hash tables") Signed-off-by: Luis Henriques <lhenriques@suse.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-05-27livepatch: Make livepatch dependent on !TRIM_UNUSED_KSYMSMiroslav Benes
If TRIM_UNUSED_KSYMS is enabled, all unneeded exported symbols are made unexported. Two-pass build of the kernel is done to find out which symbols are needed based on a configuration. This effectively complicates things for out-of-tree modules. Livepatch exports functions to (un)register and enable/disable a live patch. The only in-tree module which uses these functions is a sample in samples/livepatch/. If the sample is disabled, the functions are trimmed and out-of-tree live patches cannot be built. Note that live patches are intended to be built out-of-tree. Suggested-by: Michal Marek <mmarek@suse.com> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Acked-by: Jessica Yu <jeyu@redhat.com> Signed-off-by: Miroslav Benes <mbenes@suse.cz> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2017-05-26Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netLinus Torvalds
Pull networking fixes from David Miller: 1) Fix state pruning in bpf verifier wrt. alignment, from Daniel Borkmann. 2) Handle non-linear SKBs properly in SCTP ICMP parsing, from Davide Caratti. 3) Fix bit field definitions for rss_hash_type of descriptors in mlx5 driver, from Jesper Brouer. 4) Defer slave->link updates until bonding is ready to do a full commit to the new settings, from Nithin Sujir. 5) Properly reference count ipv4 FIB metrics to avoid use after free situations, from Eric Dumazet and several others including Cong Wang and Julian Anastasov. 6) Fix races in llc_ui_bind(), from Lin Zhang. 7) Fix regression of ESP UDP encapsulation for TCP packets, from Steffen Klassert. 8) Fix mdio-octeon driver Kconfig deps, from Randy Dunlap. 9) Fix regression in setting DSCP on ipv6/GRE encapsulation, from Peter Dawson. * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (43 commits) ipv4: add reference counting to metrics net: ethernet: ax88796: don't call free_irq without request_irq first ip6_tunnel, ip6_gre: fix setting of DSCP on encapsulated packets sctp: fix ICMP processing if skb is non-linear net: llc: add lock_sock in llc_ui_bind to avoid a race condition bonding: Don't update slave->link until ready to commit test_bpf: Add a couple of tests for BPF_JSGE. bpf: add various verifier test cases bpf: fix wrong exposure of map_flags into fdinfo for lpm bpf: add bpf_clone_redirect to bpf_helper_changes_pkt_data bpf: properly reset caller saved regs after helper call and ld_abs/ind bpf: fix incorrect pruning decision when alignment must be tracked arp: fixed -Wuninitialized compiler warning tcp: avoid fastopen API to be used on AF_UNSPEC net: move somaxconn init from sysctl code net: fix potential null pointer dereference geneve: fix fill_info when using collect_metadata virtio-net: enable TSO/checksum offloads for Q-in-Q vlans be2net: Fix offload features for Q-in-Q packets vlan: Fix tcp checksum offloads in Q-in-Q vlans ...
2017-05-25bpf: fix wrong exposure of map_flags into fdinfo for lpmDaniel Borkmann
trie_alloc() always needs to have BPF_F_NO_PREALLOC passed in via attr->map_flags, since it does not support preallocation yet. We check the flag, but we never copy the flag into trie->map.map_flags, which is later on exposed into fdinfo and used by loaders such as iproute2. Latter uses this in bpf_map_selfcheck_pinned() to test whether a pinned map has the same spec as the one from the BPF obj file and if not, bails out, which is currently the case for lpm since it exposes always 0 as flags. Also copy over flags in array_map_alloc() and stack_map_alloc(). They always have to be 0 right now, but we should make sure to not miss to copy them over at a later point in time when we add actual flags for them to use. Fixes: b95a5c4db09b ("bpf: add a longest prefix match trie map implementation") Reported-by: Jarno Rajahalme <jarno@covalent.io> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-05-25bpf: properly reset caller saved regs after helper call and ld_abs/indDaniel Borkmann
Currently, after performing helper calls, we clear all caller saved registers, that is r0 - r5 and fill r0 depending on struct bpf_func_proto specification. The way we reset these regs can affect pruning decisions in later paths, since we only reset register's imm to 0 and type to NOT_INIT. However, we leave out clearing of other variables such as id, min_value, max_value, etc, which can later on lead to pruning mismatches due to stale data. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-05-25bpf: fix incorrect pruning decision when alignment must be trackedDaniel Borkmann
Currently, when we enforce alignment tracking on direct packet access, the verifier lets the following program pass despite doing a packet write with unaligned access: 0: (61) r2 = *(u32 *)(r1 +76) 1: (61) r3 = *(u32 *)(r1 +80) 2: (61) r7 = *(u32 *)(r1 +8) 3: (bf) r0 = r2 4: (07) r0 += 14 5: (25) if r7 > 0x1 goto pc+4 R0=pkt(id=0,off=14,r=0) R1=ctx R2=pkt(id=0,off=0,r=0) R3=pkt_end R7=inv,min_value=0,max_value=1 R10=fp 6: (2d) if r0 > r3 goto pc+1 R0=pkt(id=0,off=14,r=14) R1=ctx R2=pkt(id=0,off=0,r=14) R3=pkt_end R7=inv,min_value=0,max_value=1 R10=fp 7: (63) *(u32 *)(r0 -4) = r0 8: (b7) r0 = 0 9: (95) exit from 6 to 8: R0=pkt(id=0,off=14,r=0) R1=ctx R2=pkt(id=0,off=0,r=0) R3=pkt_end R7=inv,min_value=0,max_value=1 R10=fp 8: (b7) r0 = 0 9: (95) exit from 5 to 10: R0=pkt(id=0,off=14,r=0) R1=ctx R2=pkt(id=0,off=0,r=0) R3=pkt_end R7=inv,min_value=2 R10=fp 10: (07) r0 += 1 11: (05) goto pc-6 6: safe <----- here, wrongly found safe processed 15 insns However, if we enforce a pruning mismatch by adding state into r8 which is then being mismatched in states_equal(), we find that for the otherwise same program, the verifier detects a misaligned packet access when actually walking that path: 0: (61) r2 = *(u32 *)(r1 +76) 1: (61) r3 = *(u32 *)(r1 +80) 2: (61) r7 = *(u32 *)(r1 +8) 3: (b7) r8 = 1 4: (bf) r0 = r2 5: (07) r0 += 14 6: (25) if r7 > 0x1 goto pc+4 R0=pkt(id=0,off=14,r=0) R1=ctx R2=pkt(id=0,off=0,r=0) R3=pkt_end R7=inv,min_value=0,max_value=1 R8=imm1,min_value=1,max_value=1,min_align=1 R10=fp 7: (2d) if r0 > r3 goto pc+1 R0=pkt(id=0,off=14,r=14) R1=ctx R2=pkt(id=0,off=0,r=14) R3=pkt_end R7=inv,min_value=0,max_value=1 R8=imm1,min_value=1,max_value=1,min_align=1 R10=fp 8: (63) *(u32 *)(r0 -4) = r0 9: (b7) r0 = 0 10: (95) exit from 7 to 9: R0=pkt(id=0,off=14,r=0) R1=ctx R2=pkt(id=0,off=0,r=0) R3=pkt_end R7=inv,min_value=0,max_value=1 R8=imm1,min_value=1,max_value=1,min_align=1 R10=fp 9: (b7) r0 = 0 10: (95) exit from 6 to 11: R0=pkt(id=0,off=14,r=0) R1=ctx R2=pkt(id=0,off=0,r=0) R3=pkt_end R7=inv,min_value=2 R8=imm1,min_value=1,max_value=1,min_align=1 R10=fp 11: (07) r0 += 1 12: (b7) r8 = 0 13: (05) goto pc-7 <----- mismatch due to r8 7: (2d) if r0 > r3 goto pc+1 R0=pkt(id=0,off=15,r=15) R1=ctx R2=pkt(id=0,off=0,r=15) R3=pkt_end R7=inv,min_value=2 R8=imm0,min_value=0,max_value=0,min_align=2147483648 R10=fp 8: (63) *(u32 *)(r0 -4) = r0 misaligned packet access off 2+15+-4 size 4 The reason why we fail to see it in states_equal() is that the third test in compare_ptrs_to_packet() ... if (old->off <= cur->off && old->off >= old->range && cur->off >= cur->range) return true; ... will let the above pass. The situation we run into is that old->off <= cur->off (14 <= 15), meaning that prior walked paths went with smaller offset, which was later used in the packet access after successful packet range check and found to be safe already. For example: Given is R0=pkt(id=0,off=0,r=0). Adding offset 14 as in above program to it, results in R0=pkt(id=0,off=14,r=0) before the packet range test. Now, testing this against R3=pkt_end with 'if r0 > r3 goto out' will transform R0 into R0=pkt(id=0,off=14,r=14) for the case when we're within bounds. A write into the packet at offset *(u32 *)(r0 -4), that is, 2 + 14 -4, is valid and aligned (2 is for NET_IP_ALIGN). After processing this with all fall-through paths, we later on check paths from branches. When the above skb->mark test is true, then we jump near the end of the program, perform r0 += 1, and jump back to the 'if r0 > r3 goto out' test we've visited earlier already. This time, R0 is of type R0=pkt(id=0,off=15,r=0), and we'll prune that part because this time we'll have a larger safe packet range, and we already found that with off=14 all further insn were already safe, so it's safe as well with a larger off. However, the problem is that the subsequent write into the packet with 2 + 15 -4 is then unaligned, and not caught by the alignment tracking. Note that min_align, aux_off, and aux_off_align were all 0 in this example. Since we cannot tell at this time what kind of packet access was performed in the prior walk and what minimal requirements it has (we might do so in the future, but that requires more complexity), fix it to disable this pruning case for strict alignment for now, and let the verifier do check such paths instead. With that applied, the test cases pass and reject the program due to misalignment. Fixes: d1174416747d ("bpf: Track alignment of register values in the verifier.") Reference: http://patchwork.ozlabs.org/patch/761909/ Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-05-24cpuset: consider dying css as offlineTejun Heo
In most cases, a cgroup controller don't care about the liftimes of cgroups. For the controller, a css becomes online when ->css_online() is called on it and offline when ->css_offline() is called. However, cpuset is special in that the user interface it exposes cares whether certain cgroups exist or not. Combined with the RCU delay between cgroup removal and css offlining, this can lead to user visible behavior oddities where operations which should succeed after cgroup removals fail for some time period. The effects of cgroup removals are delayed when seen from userland. This patch adds css_is_dying() which tests whether offline is pending and updates is_cpuset_online() so that the function returns false also while offline is pending. This gets rid of the userland visible delays. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Daniel Jordan <daniel.m.jordan@oracle.com> Link: http://lkml.kernel.org/r/327ca1f5-7957-fbb9-9e5f-9ba149d40ba2@oracle.com Cc: stable@vger.kernel.org Signed-off-by: Tejun Heo <tj@kernel.org>
2017-05-24Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace Pull ptrace fix from Eric Biederman: "This fixes a brown paper bag bug. When I fixed the ptrace interaction with user namespaces I added a new field ptracer_cred in struct_task and I failed to properly initialize it on fork. This dangling pointer wound up breaking runing setuid applications run from the enlightenment window manager. As this is the worst sort of bug. A regression breaking user space for no good reason let's get this fixed" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: ptrace: Properly initialize ptracer_cred on fork
2017-05-23posix-timers: Make signal printks conditionalThomas Gleixner
A recent commit added extra printks for CPU/RT limits. This can result in excessive spam in dmesg. Make the printks conditional on print_fatal_signals. Fixes: e7ea7c9806a2 ("rlimits: Print more information when CPU/RT limits are exceeded") Reported-by: Dave Jones <davej@codemonkey.org.uk> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Arun Raghavan <arun@arunraghavan.net>
2017-05-23ptrace: Properly initialize ptracer_cred on forkEric W. Biederman
When I introduced ptracer_cred I failed to consider the weirdness of fork where the task_struct copies the old value by default. This winds up leaving ptracer_cred set even when a process forks and the child process does not wind up being ptraced. Because ptracer_cred is not set on non-ptraced processes whose parents were ptraced this has broken the ability of the enlightenment window manager to start setuid children. Fix this by properly initializing ptracer_cred in ptrace_init_task This must be done with a little bit of care to preserve the current value of ptracer_cred when ptrace carries through fork. Re-reading the ptracer_cred from the ptracing process at this point is inconsistent with how PT_PTRACE_CAP has been maintained all of these years. Tested-by: Takashi Iwai <tiwai@suse.de> Fixes: 64b875f7ac8a ("ptrace: Capture the ptracer's creds not PT_PTRACE_CAP") Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2017-05-22Merge tag 'pm-4.12-rc3' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull power management fixes from Rafael Wysocki: "These fix RTC wakeup from suspend-to-idle broken recently, fix CPU idleness detection condition in the schedutil cpufreq governor, fix a cpufreq driver build failure, fix an error code path in the power capping framework, clean up the hibernate core and update the intel_pstate documentation. Specifics: - Fix RTC wakeup from suspend-to-idle broken by the recent rework of ACPI wakeup handling (Rafael Wysocki). - Update intel_pstate driver documentation to reflect the current code and explain how it works in more detail (Rafael Wysocki). - Fix an issue related to CPU idleness detection on systems with shared cpufreq policies in the schedutil governor (Juri Lelli). - Fix a possible build issue in the dbx500 cpufreq driver (Arnd Bergmann). - Fix a function in the power capping framework core to return an error code instead of 0 when there's an error (Dan Carpenter). - Clean up variable definition in the hibernation core (Pushkar Jambhlekar)" * tag 'pm-4.12-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: cpufreq: dbx500: add a Kconfig symbol PM / hibernate: Declare variables as static PowerCap: Fix an error code in powercap_register_zone() RTC: rtc-cmos: Fix wakeup from suspend-to-idle PM / wakeup: Fix up wakeup_source_report_event() cpufreq: intel_pstate: Document the current behavior and user interface cpufreq: schedutil: use now as reference when aggregating shared policy requests
2017-05-22kthread: Fix use-after-free if kthread fork failsVegard Nossum
If a kthread forks (e.g. usermodehelper since commit 1da5c46fa965) but fails in copy_process() between calling dup_task_struct() and setting p->set_child_tid, then the value of p->set_child_tid will be inherited from the parent and get prematurely freed by free_kthread_struct(). kthread() - worker_thread() - process_one_work() | - call_usermodehelper_exec_work() | - kernel_thread() | - _do_fork() | - copy_process() | - dup_task_struct() | - arch_dup_task_struct() | - tsk->set_child_tid = current->set_child_tid // implied | - ... | - goto bad_fork_* | - ... | - free_task(tsk) | - free_kthread_struct(tsk) | - kfree(tsk->set_child_tid) - ... - schedule() - __schedule() - wq_worker_sleeping() - kthread_data(task)->flags // UAF The problem started showing up with commit 1da5c46fa965 since it reused ->set_child_tid for the kthread worker data. A better long-term solution might be to get rid of the ->set_child_tid abuse. The comment in set_kthread_struct() also looks slightly wrong. Debugged-by: Jamie Iles <jamie.iles@oracle.com> Fixes: 1da5c46fa965 ("kthread: Make struct kthread kmalloc'ed") Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com> Acked-by: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Jamie Iles <jamie.iles@oracle.com> Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/20170509073959.17858-1-vegard.nossum@oracle.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2017-05-22futex,rt_mutex: Fix rt_mutex_cleanup_proxy_lock()Peter Zijlstra
Markus reported that the glibc/nptl/tst-robustpi8 test was failing after commit: cfafcd117da0 ("futex: Rework futex_lock_pi() to use rt_mutex_*_proxy_lock()") The following trace shows the problem: ld-linux-x86-64-2161 [019] .... 410.760971: SyS_futex: 00007ffbeb76b028: 80000875 op=FUTEX_LOCK_PI ld-linux-x86-64-2161 [019] ...1 410.760972: lock_pi_update_atomic: 00007ffbeb76b028: curval=80000875 uval=80000875 newval=80000875 ret=0 ld-linux-x86-64-2165 [011] .... 410.760978: SyS_futex: 00007ffbeb76b028: 80000875 op=FUTEX_UNLOCK_PI ld-linux-x86-64-2165 [011] d..1 410.760979: do_futex: 00007ffbeb76b028: curval=80000875 uval=80000875 newval=80000871 ret=0 ld-linux-x86-64-2165 [011] .... 410.760980: SyS_futex: 00007ffbeb76b028: 80000871 ret=0000 ld-linux-x86-64-2161 [019] .... 410.760980: SyS_futex: 00007ffbeb76b028: 80000871 ret=ETIMEDOUT Task 2165 does an UNLOCK_PI, assigning the lock to the waiter task 2161 which then returns with -ETIMEDOUT. That wrecks the lock state, because now the owner isn't aware it acquired the lock and removes the pending robust list entry. If 2161 is killed, the robust list will not clear out this futex and the subsequent acquire on this futex will then (correctly) result in -ESRCH which is unexpected by glibc, triggers an internal assertion and dies. Task 2161 Task 2165 rt_mutex_wait_proxy_lock() timeout(); /* T2161 is still queued in the waiter list */ return -ETIMEDOUT; futex_unlock_pi() spin_lock(hb->lock); rtmutex_unlock() remove_rtmutex_waiter(T2161); mark_lock_available(); /* Make the next waiter owner of the user space side */ futex_uval = 2161; spin_unlock(hb->lock); spin_lock(hb->lock); rt_mutex_cleanup_proxy_lock() if (rtmutex_owner() !== current) ... return FAIL; .... return -ETIMEOUT; This means that rt_mutex_cleanup_proxy_lock() needs to call try_to_take_rt_mutex() so it can take over the rtmutex correctly which was assigned by the waker. If the rtmutex is owned by some other task then this call is harmless and just confirmes that the waiter is not able to acquire it. While there, fix what looks like a merge error which resulted in rt_mutex_cleanup_proxy_lock() having two calls to fixup_rt_mutex_waiters() and rt_mutex_wait_proxy_lock() not having any. Both should have one, since both potentially touch the waiter list. Fixes: 38d589f2fd08 ("futex,rt_mutex: Restructure rt_mutex_finish_proxy_lock()") Reported-by: Markus Trippelsdorf <markus@trippelsdorf.de> Bug-Spotted-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Florian Weimer <fweimer@redhat.com> Cc: Darren Hart <dvhart@infradead.org> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Markus Trippelsdorf <markus@trippelsdorf.de> Link: http://lkml.kernel.org/r/20170519154850.mlomgdsd26drq5j6@hirez.programming.kicks-ass.net Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2017-05-22Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netLinus Torvalds
Pull networking fixes from David Miller: "Mostly netfilter bug fixes in here, but we have some bits elsewhere as well. 1) Don't do SNAT replies for non-NATed connections in IPVS, from Julian Anastasov. 2) Don't delete conntrack helpers while they are still in use, from Liping Zhang. 3) Fix zero padding in xtables's xt_data_to_user(), from Willem de Bruijn. 4) Add proper RCU protection to nf_tables_dump_set() because we cannot guarantee that we hold the NFNL_SUBSYS_NFTABLES lock. From Liping Zhang. 5) Initialize rcv_mss in tcp_disconnect(), from Wei Wang. 6) smsc95xx devices can't handle IPV6 checksums fully, so don't advertise support for offloading them. From Nisar Sayed. 7) Fix out-of-bounds access in __ip6_append_data(), from Eric Dumazet. 8) Make atl2_probe() propagate the error code properly on failures, from Alexey Khoroshilov. 9) arp_target[] in bond_check_params() is used uninitialized. This got changes from a global static to a local variable, which is how this mistake happened. Fix from Jarod Wilson. 10) Fix fallout from unnecessary NULL check removal in cls_matchall, from Jiri Pirko. This is definitely brown paper bag territory..." * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (26 commits) net: sched: cls_matchall: fix null pointer dereference vsock: use new wait API for vsock_stream_sendmsg() bonding: fix randomly populated arp target array net: Make IP alignment calulations clearer. bonding: fix accounting of active ports in 3ad net: atheros: atl2: don't return zero on failure path in atl2_probe() ipv6: fix out of bound writes in __ip6_append_data() bridge: start hello_timer when enabling KERNEL_STP in br_stp_start smsc95xx: Support only IPv4 TCP/UDP csum offload arp: always override existing neigh entries with gratuitous ARP arp: postpone addr_type calculation to as late as possible arp: decompose is_garp logic into a separate function arp: fixed error in a comment tcp: initialize rcv_mss to TCP_MIN_MSS instead of 0 netfilter: xtables: fix build failure from COMPAT_XT_ALIGN outside CONFIG_COMPAT ebtables: arpreply: Add the standard target sanity check netfilter: nf_tables: revisit chain/object refcounting from elements netfilter: nf_tables: missing sanitization in data from userspace netfilter: nf_tables: can't assume lock is acquired when dumping set elems netfilter: synproxy: fix conntrackd interaction ...
2017-05-22Merge branches 'pm-sleep' and 'powercap'Rafael J. Wysocki
* pm-sleep: PM / hibernate: Declare variables as static RTC: rtc-cmos: Fix wakeup from suspend-to-idle PM / wakeup: Fix up wakeup_source_report_event() * powercap: PowerCap: Fix an error code in powercap_register_zone()
2017-05-22Merge branches 'intel_pstate', 'pm-cpufreq' and 'pm-cpufreq-sched'Rafael J. Wysocki
* intel_pstate: cpufreq: intel_pstate: Document the current behavior and user interface * pm-cpufreq: cpufreq: dbx500: add a Kconfig symbol * pm-cpufreq-sched: cpufreq: schedutil: use now as reference when aggregating shared policy requests
2017-05-22net: Make IP alignment calulations clearer.David S. Miller
The assignmnet: ip_align = strict ? 2 : NET_IP_ALIGN; in compare_pkt_ptr_alignment() trips up Coverity because we can only get to this code when strict is true, therefore ip_align will always be 2 regardless of NET_IP_ALIGN's value. So just assign directly to '2' and explain the situation in the comment above. Reported-by: "Gustavo A. R. Silva" <garsilva@embeddedor.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-05-21Merge branch 'sched-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler fix from Thomas Gleixner: "A single scheduler fix: Prevent idle task from ever being preempted. That makes sure that synchronize_rcu_tasks() which is ignoring idle task does not pretend that no task is stuck in preempted state. If that happens and idle was preempted on a ftrace trampoline the machine crashes due to inconsistent state" * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/core: Call __schedule() from do_idle() without enabling preemption
2017-05-21Merge branch 'irq-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull irq fixes from Thomas Gleixner: "A set of small fixes for the irq subsystem: - Cure a data ordering problem with chained interrupts - Three small fixlets for the mbigen irq chip" * 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: genirq: Fix chained interrupt data ordering irqchip/mbigen: Fix the clear register offset calculation irqchip/mbigen: Fix potential NULL dereferencing irqchip/mbigen: Fix memory mapping code