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2018-03-24genirq: Use irqd_get_trigger_type to compare the trigger type for shared IRQsHans de Goede1-1/+3
[ Upstream commit 382bd4de61827dbaaf5fb4fb7b1f4be4a86505e7 ] When requesting a shared irq with IRQF_TRIGGER_NONE then the irqaction flags get filled with the trigger type from the irq_data: if (!(new->flags & IRQF_TRIGGER_MASK)) new->flags |= irqd_get_trigger_type(&desc->irq_data); On the first setup_irq() the trigger type in irq_data is NONE when the above code executes, then the irq is started up for the first time and then the actual trigger type gets established, but that's too late to fix up new->flags. When then a second user of the irq requests the irq with IRQF_TRIGGER_NONE its irqaction's triggertype gets set to the actual trigger type and the following check fails: if (!((old->flags ^ new->flags) & IRQF_TRIGGER_MASK)) Resulting in the request_irq failing with -EBUSY even though both users requested the irq with IRQF_SHARED | IRQF_TRIGGER_NONE Fix this by comparing the new irqaction's trigger type to the trigger type stored in the irq_data which correctly reflects the actual trigger type being used for the irq. Suggested-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Hans de Goede <hdegoede@redhat.com> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Link: http://lkml.kernel.org/r/20170415100831.17073-1-hdegoede@redhat.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-24time: Change posix clocks ops interfaces to use timespec64Deepa Dinamani1-10/+24
[ Upstream commit d340266e19ddb70dbd608f9deedcfb35fdb9d419 ] struct timespec is not y2038 safe on 32 bit machines. The posix clocks apis use struct timespec directly and through struct itimerspec. Replace the posix clock interfaces to use struct timespec64 and struct itimerspec64 instead. Also fix up their implementations accordingly. Note that the clock_getres() interface has also been changed to use timespec64 even though this particular interface is not affected by the y2038 problem. This helps verification for internal kernel code for y2038 readiness by getting rid of time_t/ timeval/ timespec. Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com> Cc: arnd@arndb.de Cc: y2038@lists.linaro.org Cc: netdev@vger.kernel.org Cc: Richard Cochran <richardcochran@gmail.com> Cc: john.stultz@linaro.org Link: http://lkml.kernel.org/r/1490555058-4603-3-git-send-email-deepa.kernel@gmail.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-22locking/locktorture: Fix num reader/writer corner casesDavidlohr Bueso1-32/+44
[ Upstream commit 2ce77d16db4240dd2e422fc0a5c26d3e2ec03446 ] Things can explode for locktorture if the user does combinations of nwriters_stress=0 nreaders_stress=0. Fix this by not assuming we always want to torture writer threads. Reported-by: Jeremy Linton <jeremy.linton@arm.com> Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Jeremy Linton <jeremy.linton@arm.com> Tested-by: Jeremy Linton <jeremy.linton@arm.com> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-22sched: Stop resched_cpu() from sending IPIs to offline CPUsPaul E. McKenney1-1/+2
[ Upstream commit a0982dfa03efca6c239c52cabebcea4afb93ea6b ] The rcutorture test suite occasionally provokes a splat due to invoking resched_cpu() on an offline CPU: WARNING: CPU: 2 PID: 8 at /home/paulmck/public_git/linux-rcu/arch/x86/kernel/smp.c:128 native_smp_send_reschedule+0x37/0x40 Modules linked in: CPU: 2 PID: 8 Comm: rcu_preempt Not tainted 4.14.0-rc4+ #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014 task: ffff902ede9daf00 task.stack: ffff96c50010c000 RIP: 0010:native_smp_send_reschedule+0x37/0x40 RSP: 0018:ffff96c50010fdb8 EFLAGS: 00010096 RAX: 000000000000002e RBX: ffff902edaab4680 RCX: 0000000000000003 RDX: 0000000080000003 RSI: 0000000000000000 RDI: 00000000ffffffff RBP: ffff96c50010fdb8 R08: 0000000000000000 R09: 0000000000000001 R10: 0000000000000000 R11: 00000000299f36ae R12: 0000000000000001 R13: ffffffff9de64240 R14: 0000000000000001 R15: ffffffff9de64240 FS: 0000000000000000(0000) GS:ffff902edfc80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000f7d4c642 CR3: 000000001e0e2000 CR4: 00000000000006e0 Call Trace: resched_curr+0x8f/0x1c0 resched_cpu+0x2c/0x40 rcu_implicit_dynticks_qs+0x152/0x220 force_qs_rnp+0x147/0x1d0 ? sync_rcu_exp_select_cpus+0x450/0x450 rcu_gp_kthread+0x5a9/0x950 kthread+0x142/0x180 ? force_qs_rnp+0x1d0/0x1d0 ? kthread_create_on_node+0x40/0x40 ret_from_fork+0x27/0x40 Code: 14 01 0f 92 c0 84 c0 74 14 48 8b 05 14 4f f4 00 be fd 00 00 00 ff 90 a0 00 00 00 5d c3 89 fe 48 c7 c7 38 89 ca 9d e8 e5 56 08 00 <0f> ff 5d c3 0f 1f 44 00 00 8b 05 52 9e 37 02 85 c0 75 38 55 48 ---[ end trace 26df9e5df4bba4ac ]--- This splat cannot be generated by expedited grace periods because they always invoke resched_cpu() on the current CPU, which is good because expedited grace periods require that resched_cpu() unconditionally succeed. However, other parts of RCU can tolerate resched_cpu() acting as a no-op, at least as long as it doesn't happen too often. This commit therefore makes resched_cpu() invoke resched_curr() only if the CPU is either online or is the current CPU. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-22sched: Stop switched_to_rt() from sending IPIs to offline CPUsPaul E. McKenney1-1/+1
[ Upstream commit 2fe2582649aa2355f79acddb86bd4d6c5363eb63 ] The rcutorture test suite occasionally provokes a splat due to invoking rt_mutex_lock() which needs to boost the priority of a task currently sitting on a runqueue that belongs to an offline CPU: WARNING: CPU: 0 PID: 12 at /home/paulmck/public_git/linux-rcu/arch/x86/kernel/smp.c:128 native_smp_send_reschedule+0x37/0x40 Modules linked in: CPU: 0 PID: 12 Comm: rcub/7 Not tainted 4.14.0-rc4+ #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014 task: ffff9ed3de5f8cc0 task.stack: ffffbbf80012c000 RIP: 0010:native_smp_send_reschedule+0x37/0x40 RSP: 0018:ffffbbf80012fd10 EFLAGS: 00010082 RAX: 000000000000002f RBX: ffff9ed3dd9cb300 RCX: 0000000000000004 RDX: 0000000080000004 RSI: 0000000000000086 RDI: 00000000ffffffff RBP: ffffbbf80012fd10 R08: 000000000009da7a R09: 0000000000007b9d R10: 0000000000000001 R11: ffffffffbb57c2cd R12: 000000000000000d R13: ffff9ed3de5f8cc0 R14: 0000000000000061 R15: ffff9ed3ded59200 FS: 0000000000000000(0000) GS:ffff9ed3dea00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000080686f0 CR3: 000000001b9e0000 CR4: 00000000000006f0 Call Trace: resched_curr+0x61/0xd0 switched_to_rt+0x8f/0xa0 rt_mutex_setprio+0x25c/0x410 task_blocks_on_rt_mutex+0x1b3/0x1f0 rt_mutex_slowlock+0xa9/0x1e0 rt_mutex_lock+0x29/0x30 rcu_boost_kthread+0x127/0x3c0 kthread+0x104/0x140 ? rcu_report_unblock_qs_rnp+0x90/0x90 ? kthread_create_on_node+0x40/0x40 ret_from_fork+0x22/0x30 Code: f0 00 0f 92 c0 84 c0 74 14 48 8b 05 34 74 c5 00 be fd 00 00 00 ff 90 a0 00 00 00 5d c3 89 fe 48 c7 c7 a0 c6 fc b9 e8 d5 b5 06 00 <0f> ff 5d c3 0f 1f 44 00 00 8b 05 a2 d1 13 02 85 c0 75 38 55 48 But the target task's priority has already been adjusted, so the only purpose of switched_to_rt() invoking resched_curr() is to wake up the CPU running some task that needs to be preempted by the boosted task. But the CPU is offline, which presumably means that the task must be migrated to some other CPU, and that this other CPU will undertake any needed preemption at the time of migration. Because the runqueue lock is held when resched_curr() is invoked, we know that the boosted task cannot go anywhere, so it is not necessary to invoke resched_curr() in this particular case. This commit therefore makes switched_to_rt() refrain from invoking resched_curr() when the target CPU is offline. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-22printk: Correctly handle preemption in console_unlock()Petr Mladek1-2/+6
[ Upstream commit 257ab443118bffc7fdcef38f49cf59be68a3e362 ] Some console drivers code calls console_conditional_schedule() that looks at @console_may_schedule. The value must be cleared when the drivers are called from console_unlock() with interrupts disabled. But rescheduling is fine when the same code is called, for example, from tty operations where the console semaphore is taken via console_lock(). This is why @console_may_schedule is cleared before calling console drivers. The original value is stored to decide if we could sleep between lines. Now, @console_may_schedule is not cleared when we call console_trylock() and jump back to the "again" goto label. This has become a problem, since the commit 6b97a20d3a7909daa066 ("printk: set may_schedule for some of console_trylock() callers"). @console_may_schedule might get enabled now. There is also the opposite problem. console_lock() can be called only from preemptive context. It can always enable scheduling in the console code. But console_trylock() is not able to detect it when CONFIG_PREEMPT_COUNT is disabled. Therefore we should use the original @console_may_schedule value after re-acquiring the console semaphore in console_unlock(). This patch solves both problems by moving the "again" goto label. Alternative solution was to clear and restore the value around call_console_drivers(). Then console_conditional_schedule() could be used also inside console_unlock(). But there was a potential race with console_flush_on_panic() as reported by Sergey Senozhatsky. That function should be called only where there is only one CPU and with interrupts disabled. But better be on the safe side because stopping CPUs might fail. Fixes: 6b97a20d3a7909 ("printk: set may_schedule for some of console_trylock() callers") Link: http://lkml.kernel.org/r/1490372045-22288-1-git-send-email-pmladek@suse.com Suggested-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jiri Slaby <jslaby@suse.cz> Cc: linux-fbdev@vger.kernel.org Cc: linux-kernel@vger.kernel.org Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-22rtmutex: Fix PI chain order integrityPeter Zijlstra2-2/+28
[ Upstream commit e0aad5b44ff5d28ac1d6ae70cdf84ca228e889dc ] rt_mutex_waiter::prio is a copy of task_struct::prio which is updated during the PI chain walk, such that the PI chain order isn't messed up by (asynchronous) task state updates. Currently rt_mutex_waiter_less() uses task state for deadline tasks; this is broken, since the task state can, as said above, change asynchronously, causing the RB tree order to change without actual tree update -> FAIL. Fix this by also copying the deadline into the rt_mutex_waiter state and updating it along with its prio field. Ideally we would also force PI chain updates whenever DL tasks update their deadline parameter, but for first approximation this is less broken than it was. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: juri.lelli@arm.com Cc: bigeasy@linutronix.de Cc: xlpang@redhat.com Cc: rostedt@goodmis.org Cc: mathieu.desnoyers@efficios.com Cc: jdesfossez@efficios.com Cc: bristot@redhat.com Link: http://lkml.kernel.org/r/20170323150216.403992539@infradead.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-22braille-console: Fix value returned by _braille_console_setupSamuel Thibault2-10/+18
[ Upstream commit 2ed2b8621be2708c0f6d61fe9841e9ad8b9753f0 ] commit bbeddf52adc1 ("printk: move braille console support into separate braille.[ch] files") introduced _braille_console_setup() to outline the braille initialization code. There was however some confusion over the value it was supposed to return. commit 2cfe6c4ac7ee ("printk: Fix return of braille_register_console()") tried to fix it but failed to. This fixes and documents the returned value according to the use in printk.c: non-zero return means a parsing error, and thus this console configuration should be ignored. Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org> Cc: Aleksey Makarov <aleksey.makarov@linaro.org> Cc: Joe Perches <joe@perches.com> Cc: Ming Lei <ming.lei@canonical.com> Cc: Steven Rostedt <rostedt@goodmis.org> Acked-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-22sysrq: Reset the watchdog timers while displaying high-resolution timersTom Hromatka1-0/+6
[ Upstream commit 0107042768658fea9f5f5a9c00b1c90f5dab6a06 ] On systems with a large number of CPUs, running sysrq-<q> can cause watchdog timeouts. There are two slow sections of code in the sysrq-<q> path in timer_list.c. 1. print_active_timers() - This function is called by print_cpu() and contains a slow goto loop. On a machine with hundreds of CPUs, this loop took approximately 100ms for the first CPU in a NUMA node. (Subsequent CPUs in the same node ran much quicker.) The total time to print all of the CPUs is ultimately long enough to trigger the soft lockup watchdog. 2. print_tickdevice() - This function outputs a large amount of textual information. This function also took approximately 100ms per CPU. Since sysrq-<q> is not a performance critical path, there should be no harm in touching the nmi watchdog in both slow sections above. Touching it in just one location was insufficient on systems with hundreds of CPUs as occasional timeouts were still observed during testing. This issue was observed on an Oracle T7 machine with 128 CPUs, but I anticipate it may affect other systems with similarly large numbers of CPUs. Signed-off-by: Tom Hromatka <tom.hromatka@oracle.com> Reviewed-by: Rob Gardner <rob.gardner@oracle.com> Signed-off-by: John Stultz <john.stultz@linaro.org> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-22timers, sched_clock: Update timeout for clock wrapDavid Engraf1-0/+5
[ Upstream commit 1b8955bc5ac575009835e371ae55e7f3af2197a9 ] The scheduler clock framework may not use the correct timeout for the clock wrap. This happens when a new clock driver calls sched_clock_register() after the kernel called sched_clock_postinit(). In this case the clock wrap timeout is too long thus sched_clock_poll() is called too late and the clock already wrapped. On my ARM system the scheduler was no longer scheduling any other task than the idle task because the sched_clock() wrapped. Signed-off-by: David Engraf <david.engraf@sysgo.com> Signed-off-by: John Stultz <john.stultz@linaro.org> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-18workqueue: Allow retrieval of current task's work structLukas Wunner1-0/+16
commit 27d4ee03078aba88c5e07dcc4917e8d01d046f38 upstream. Introduce a helper to retrieve the current task's work struct if it is a workqueue worker. This allows us to fix a long-standing deadlock in several DRM drivers wherein the ->runtime_suspend callback waits for a specific worker to finish and that worker in turn calls a function which waits for runtime suspend to finish. That function is invoked from multiple call sites and waiting for runtime suspend to finish is the correct thing to do except if it's executing in the context of the worker. Cc: Lai Jiangshan <jiangshanlai@gmail.com> Cc: Dave Airlie <airlied@redhat.com> Cc: Ben Skeggs <bskeggs@redhat.com> Cc: Alex Deucher <alexander.deucher@amd.com> Acked-by: Tejun Heo <tj@kernel.org> Reviewed-by: Lyude Paul <lyude@redhat.com> Signed-off-by: Lukas Wunner <lukas@wunner.de> Link: https://patchwork.freedesktop.org/patch/msgid/2d8f603074131eb87e588d2b803a71765bd3a2fd.1518338788.git.lukas@wunner.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-11bpf: add schedule points in percpu arrays managementEric Dumazet1-1/+4
[ upstream commit 32fff239de37ef226d5b66329dd133f64d63b22d ] syszbot managed to trigger RCU detected stalls in bpf_array_free_percpu() It takes time to allocate a huge percpu map, but even more time to free it. Since we run in process context, use cond_resched() to yield cpu if needed. Fixes: a10423b87a7e ("bpf: introduce BPF_MAP_TYPE_PERCPU_ARRAY map") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-11bpf: fix mlock precharge on arraymapsDaniel Borkmann1-11/+18
[ upstream commit 9c2d63b843a5c8a8d0559cc067b5398aa5ec3ffc ] syzkaller recently triggered OOM during percpu map allocation; while there is work in progress by Dennis Zhou to add __GFP_NORETRY semantics for percpu allocator under pressure, there seems also a missing bpf_map_precharge_memlock() check in array map allocation. Given today the actual bpf_map_charge_memlock() happens after the find_and_alloc_map() in syscall path, the bpf_map_precharge_memlock() is there to bail out early before we go and do the map setup work when we find that we hit the limits anyway. Therefore add this for array map as well. Fixes: 6c9059817432 ("bpf: pre-allocate hash map elements") Fixes: a10423b87a7e ("bpf: introduce BPF_MAP_TYPE_PERCPU_ARRAY map") Reported-by: syzbot+adb03f3f0bb57ce3acda@syzkaller.appspotmail.com Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Cc: Dennis Zhou <dennisszhou@gmail.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-11bpf: fix wrong exposure of map_flags into fdinfo for lpmDaniel Borkmann2-0/+2
[ upstream commit a316338cb71a3260201490e615f2f6d5c0d8fb2c ] 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> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-11timers: Forward timer base before migrating timersLingutla Chandrasekhar1-0/+6
commit c52232a49e203a65a6e1a670cd5262f59e9364a0 upstream. On CPU hotunplug the enqueued timers of the unplugged CPU are migrated to a live CPU. This happens from the control thread which initiated the unplug. If the CPU on which the control thread runs came out from a longer idle period then the base clock of that CPU might be stale because the control thread runs prior to any event which forwards the clock. In such a case the timers from the unplugged CPU are queued on the live CPU based on the stale clock which can cause large delays due to increased granularity of the outer timer wheels which are far away from base:;clock. But there is a worse problem than that. The following sequence of events illustrates it: - CPU0 timer1 is queued expires = 59969 and base->clk = 59131. The timer is queued at wheel level 2, with resulting expiry time = 60032 (due to level granularity). - CPU1 enters idle @60007, with next timer expiry @60020. - CPU0 is hotplugged at @60009 - CPU1 exits idle and runs the control thread which migrates the timers from CPU0 timer1 is now queued in level 0 for immediate handling in the next softirq because the requested expiry time 59969 is before CPU1 base->clk 60007 - CPU1 runs code which forwards the base clock which succeeds because the next expiring timer. which was collected at idle entry time is still set to 60020. So it forwards beyond 60007 and therefore misses to expire the migrated timer1. That timer gets expired when the wheel wraps around again, which takes between 63 and 630ms depending on the HZ setting. Address both problems by invoking forward_timer_base() for the control CPUs timer base. All other places, which might run into a similar problem (mod_timer()/add_timer_on()) already invoke forward_timer_base() to avoid that. [ tglx: Massaged comment and changelog ] Fixes: a683f390b93f ("timers: Forward the wheel clock whenever possible") Co-developed-by: Neeraj Upadhyay <neeraju@codeaurora.org> Signed-off-by: Neeraj Upadhyay <neeraju@codeaurora.org> Signed-off-by: Lingutla Chandrasekhar <clingutla@codeaurora.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Anna-Maria Gleixner <anna-maria@linutronix.de> Cc: linux-arm-msm@vger.kernel.org Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20180118115022.6368-1-clingutla@codeaurora.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-03genirq: Guard handle_bad_irq log messagesGuenter Roeck1-0/+5
[ Upstream commit 11bca0a83f83f6093d816295668e74ef24595944 ] An interrupt storm on a bad interrupt will cause the kernel log to be clogged. [ 60.089234] ->handle_irq(): ffffffffbe2f803f, [ 60.090455] 0xffffffffbf2af380 [ 60.090510] handle_bad_irq+0x0/0x2e5 [ 60.090522] ->irq_data.chip(): ffffffffbf2af380, [ 60.090553] IRQ_NOPROBE set [ 60.090584] ->handle_irq(): ffffffffbe2f803f, [ 60.090590] handle_bad_irq+0x0/0x2e5 [ 60.090596] ->irq_data.chip(): ffffffffbf2af380, [ 60.090602] 0xffffffffbf2af380 [ 60.090608] ->action(): (null) [ 60.090779] handle_bad_irq+0x0/0x2e5 This was seen when running an upstream kernel on Acer Chromebook R11. The system was unstable as result. Guard the log message with __printk_ratelimit to reduce the impact. This won't prevent the interrupt storm from happening, but at least the system remains stable. Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Dmitry Torokhov <dtor@chromium.org> Cc: Joe Perches <joe@perches.com> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Mika Westerberg <mika.westerberg@linux.intel.com> Link: https://bugzilla.kernel.org/show_bug.cgi?id=197953 Link: https://lkml.kernel.org/r/1512234784-21038-1-git-send-email-linux@roeck-us.net Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-03hrtimer: Ensure POSIX compliance (relative CLOCK_REALTIME hrtimers)Anna-Maria Gleixner1-1/+6
commit 48d0c9becc7f3c66874c100c126459a9da0fdced upstream. The POSIX specification defines that relative CLOCK_REALTIME timers are not affected by clock modifications. Those timers have to use CLOCK_MONOTONIC to ensure POSIX compliance. The introduction of the additional HRTIMER_MODE_PINNED mode broke this requirement for pinned timers. There is no user space visible impact because user space timers are not using pinned mode, but for consistency reasons this needs to be fixed. Check whether the mode has the HRTIMER_MODE_REL bit set instead of comparing with HRTIMER_MODE_ABS. Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de> Cc: Christoph Hellwig <hch@lst.de> Cc: John Stultz <john.stultz@linaro.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: keescook@chromium.org Fixes: 597d0275736d ("timers: Framework for identifying pinned timers") Link: http://lkml.kernel.org/r/20171221104205.7269-7-anna-maria@linutronix.de Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Mike Galbraith <efault@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-28mm: Fix devm_memremap_pages() collision handlingJan H. Schönherr1-5/+8
commit 77dd66a3c67c93ab401ccc15efff25578be281fd upstream. If devm_memremap_pages() detects a collision while adding entries to the radix-tree, we call pgmap_radix_release(). Unfortunately, the function removes *all* entries for the range -- including the entries that caused the collision in the first place. Modify pgmap_radix_release() to take an additional argument to indicate where to stop, so that only newly added entries are removed from the tree. Cc: <stable@vger.kernel.org> Fixes: 9476df7d80df ("mm: introduce find_dev_pagemap()") Signed-off-by: Jan H. Schönherr <jschoenh@amazon.de> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-25kcov: detect double association with a single taskDmitry Vyukov1-2/+2
commit a77660d231f8b3d84fd23ed482e0964f7aa546d6 upstream. Currently KCOV_ENABLE does not check if the current task is already associated with another kcov descriptor. As the result it is possible to associate a single task with more than one kcov descriptor, which later leads to a memory leak of the old descriptor. This relation is really meant to be one-to-one (task has only one back link). Extend validation to detect such misuse. Link: http://lkml.kernel.org/r/20180122082520.15716-1-dvyukov@google.com Fixes: 5c9a8750a640 ("kernel: add kcov code coverage") Signed-off-by: Dmitry Vyukov <dvyukov@google.com> Reported-by: Shankara Pailoor <sp3485@columbia.edu> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: syzbot <syzkaller@googlegroups.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>
2018-02-25blktrace: fix unlocked registration of tracepointsJens Axboe1-10/+22
commit a6da0024ffc19e0d47712bb5ca4fd083f76b07df upstream. We need to ensure that tracepoints are registered and unregistered with the users of them. The existing atomic count isn't enough for that. Add a lock around the tracepoints, so we serialize access to them. This fixes cases where we have multiple users setting up and tearing down tracepoints, like this: CPU: 0 PID: 2995 Comm: syzkaller857118 Not tainted 4.14.0-rc5-next-20171018+ #36 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:16 [inline] dump_stack+0x194/0x257 lib/dump_stack.c:52 panic+0x1e4/0x41c kernel/panic.c:183 __warn+0x1c4/0x1e0 kernel/panic.c:546 report_bug+0x211/0x2d0 lib/bug.c:183 fixup_bug+0x40/0x90 arch/x86/kernel/traps.c:177 do_trap_no_signal arch/x86/kernel/traps.c:211 [inline] do_trap+0x260/0x390 arch/x86/kernel/traps.c:260 do_error_trap+0x120/0x390 arch/x86/kernel/traps.c:297 do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:310 invalid_op+0x18/0x20 arch/x86/entry/entry_64.S:905 RIP: 0010:tracepoint_add_func kernel/tracepoint.c:210 [inline] RIP: 0010:tracepoint_probe_register_prio+0x397/0x9a0 kernel/tracepoint.c:283 RSP: 0018:ffff8801d1d1f6c0 EFLAGS: 00010293 RAX: ffff8801d22e8540 RBX: 00000000ffffffef RCX: ffffffff81710f07 RDX: 0000000000000000 RSI: ffffffff85b679c0 RDI: ffff8801d5f19818 RBP: ffff8801d1d1f7c8 R08: ffffffff81710c10 R09: 0000000000000004 R10: ffff8801d1d1f6b0 R11: 0000000000000003 R12: ffffffff817597f0 R13: 0000000000000000 R14: 00000000ffffffff R15: ffff8801d1d1f7a0 tracepoint_probe_register+0x2a/0x40 kernel/tracepoint.c:304 register_trace_block_rq_insert include/trace/events/block.h:191 [inline] blk_register_tracepoints+0x1e/0x2f0 kernel/trace/blktrace.c:1043 do_blk_trace_setup+0xa10/0xcf0 kernel/trace/blktrace.c:542 blk_trace_setup+0xbd/0x180 kernel/trace/blktrace.c:564 sg_ioctl+0xc71/0x2d90 drivers/scsi/sg.c:1089 vfs_ioctl fs/ioctl.c:45 [inline] do_vfs_ioctl+0x1b1/0x1520 fs/ioctl.c:685 SYSC_ioctl fs/ioctl.c:700 [inline] SyS_ioctl+0x8f/0xc0 fs/ioctl.c:691 entry_SYSCALL_64_fastpath+0x1f/0xbe RIP: 0033:0x444339 RSP: 002b:00007ffe05bb5b18 EFLAGS: 00000206 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00000000006d66c0 RCX: 0000000000444339 RDX: 000000002084cf90 RSI: 00000000c0481273 RDI: 0000000000000009 RBP: 0000000000000082 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: ffffffffffffffff R13: 00000000c0481273 R14: 0000000000000000 R15: 0000000000000000 since we can now run these in parallel. Ensure that the exported helpers for doing this are grabbing the queue trace mutex. Reported-by: Steven Rostedt <rostedt@goodmis.org> Tested-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-22mm: Fix memory size alignment in devm_memremap_pages_release()Jan H. Schönherr1-1/+2
commit 10a0cd6e4932b5078215b1ec2c896597eec0eff9 upstream. The functions devm_memremap_pages() and devm_memremap_pages_release() use different ways to calculate the section-aligned amount of memory. The latter function may use an incorrect size if the memory region is small but straddles a section border. Use the same code for both. Cc: <stable@vger.kernel.org> Fixes: 5f29a77cd957 ("mm: fix mixed zone detection in devm_memremap_pages") Signed-off-by: Jan H. Schönherr <jschoenh@amazon.de> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-17ftrace: Remove incorrect setting of glob search fieldSteven Rostedt (VMware)1-1/+0
commit 7b6586562708d2b3a04fe49f217ddbadbbbb0546 upstream. __unregister_ftrace_function_probe() will incorrectly parse the glob filter because it resets the search variable that was setup by filter_parse_regex(). Al Viro reported this: After that call of filter_parse_regex() we could have func_g.search not equal to glob only if glob started with '!' or '*'. In the former case we would've buggered off with -EINVAL (not = 1). In the latter we would've set func_g.search equal to glob + 1, calculated the length of that thing in func_g.len and proceeded to reset func_g.search back to glob. Suppose the glob is e.g. *foo*. We end up with func_g.type = MATCH_MIDDLE_ONLY; func_g.len = 3; func_g.search = "*foo"; Feeding that to ftrace_match_record() will not do anything sane - we will be looking for names containing "*foo" (->len is ignored for that one). Link: http://lkml.kernel.org/r/20180127031706.GE13338@ZenIV.linux.org.uk Fixes: 3ba009297149f ("ftrace: Introduce ftrace_glob structure") Reviewed-by: Dmitry Safonov <0x7f454c46@gmail.com> Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org> Reported-by: Al Viro <viro@ZenIV.linux.org.uk> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-17kernel/relay.c: revert "kernel/relay.c: fix potential memory leak"Eric Biggers1-1/+0
commit a1be1f3931bfe0a42b46fef77a04593c2b136e7f upstream. This reverts commit ba62bafe942b ("kernel/relay.c: fix potential memory leak"). This commit introduced a double free bug, because 'chan' is already freed by the line: kref_put(&chan->kref, relay_destroy_channel); This bug was found by syzkaller, using the BLKTRACESETUP ioctl. Link: http://lkml.kernel.org/r/20180127004759.101823-1-ebiggers3@gmail.com Fixes: ba62bafe942b ("kernel/relay.c: fix potential memory leak") Signed-off-by: Eric Biggers <ebiggers@google.com> Reported-by: syzbot <syzkaller@googlegroups.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Zhouyi Zhou <yizhouzhou@ict.ac.cn> Cc: Jens Axboe <axboe@kernel.dk> 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>
2018-02-17kernel/async.c: revert "async: simplify lowest_in_progress()"Rasmus Villemoes1-8/+12
commit 4f7e988e63e336827f4150de48163bed05d653bd upstream. This reverts commit 92266d6ef60c ("async: simplify lowest_in_progress()") which was simply wrong: In the case where domain is NULL, we now use the wrong offsetof() in the list_first_entry macro, so we don't actually fetch the ->cookie value, but rather the eight bytes located sizeof(struct list_head) further into the struct async_entry. On 64 bit, that's the data member, while on 32 bit, that's a u64 built from func and data in some order. I think the bug happens to be harmless in practice: It obviously only affects callers which pass a NULL domain, and AFAICT the only such caller is async_synchronize_full() -> async_synchronize_full_domain(NULL) -> async_synchronize_cookie_domain(ASYNC_COOKIE_MAX, NULL) and the ASYNC_COOKIE_MAX means that in practice we end up waiting for the async_global_pending list to be empty - but it would break if somebody happened to pass (void*)-1 as the data element to async_schedule, and of course also if somebody ever does a async_synchronize_cookie_domain(, NULL) with a "finite" cookie value. Maybe the "harmless in practice" means this isn't -stable material. But I'm not completely confident my quick git grep'ing is enough, and there might be affected code in one of the earlier kernels that has since been removed, so I'll leave the decision to the stable guys. Link: http://lkml.kernel.org/r/20171128104938.3921-1-linux@rasmusvillemoes.dk Fixes: 92266d6ef60c "async: simplify lowest_in_progress()" Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Acked-by: Tejun Heo <tj@kernel.org> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Adam Wallis <awallis@codeaurora.org> Cc: Lai Jiangshan <laijs@cn.fujitsu.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>
2018-02-17sched/rt: Up the root domain ref count when passing it around via IPIsSteven Rostedt (VMware)3-2/+22
commit 364f56653708ba8bcdefd4f0da2a42904baa8eeb upstream. When issuing an IPI RT push, where an IPI is sent to each CPU that has more than one RT task scheduled on it, it references the root domain's rto_mask, that contains all the CPUs within the root domain that has more than one RT task in the runable state. The problem is, after the IPIs are initiated, the rq->lock is released. This means that the root domain that is associated to the run queue could be freed while the IPIs are going around. Add a sched_get_rd() and a sched_put_rd() that will increment and decrement the root domain's ref count respectively. This way when initiating the IPIs, the scheduler will up the root domain's ref count before releasing the rq->lock, ensuring that the root domain does not go away until the IPI round is complete. Reported-by: Pavan Kondeti <pkondeti@codeaurora.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: 4bdced5c9a292 ("sched/rt: Simplify the IPI based RT balancing logic") Link: http://lkml.kernel.org/r/CAEU1=PkiHO35Dzna8EQqNSKW1fr1y1zRQ5y66X117MG06sQtNA@mail.gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-17sched/rt: Use container_of() to get root domain in rto_push_irq_work_func()Steven Rostedt (VMware)1-7/+8
commit ad0f1d9d65938aec72a698116cd73a980916895e upstream. When the rto_push_irq_work_func() is called, it looks at the RT overloaded bitmask in the root domain via the runqueue (rq->rd). The problem is that during CPU up and down, nothing here stops rq->rd from changing between taking the rq->rd->rto_lock and releasing it. That means the lock that is released is not the same lock that was taken. Instead of using this_rq()->rd to get the root domain, as the irq work is part of the root domain, we can simply get the root domain from the irq work that is passed to the routine: container_of(work, struct root_domain, rto_push_work) This keeps the root domain consistent. Reported-by: Pavan Kondeti <pkondeti@codeaurora.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: 4bdced5c9a292 ("sched/rt: Simplify the IPI based RT balancing logic") Link: http://lkml.kernel.org/r/CAEU1=PkiHO35Dzna8EQqNSKW1fr1y1zRQ5y66X117MG06sQtNA@mail.gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-17posix-timer: Properly check sigevent->sigev_notifyThomas Gleixner1-15/+19
commit cef31d9af908243421258f1df35a4a644604efbe upstream. timer_create() specifies via sigevent->sigev_notify the signal delivery for the new timer. The valid modes are SIGEV_NONE, SIGEV_SIGNAL, SIGEV_THREAD and (SIGEV_SIGNAL | SIGEV_THREAD_ID). The sanity check in good_sigevent() is only checking the valid combination for the SIGEV_THREAD_ID bit, i.e. SIGEV_SIGNAL, but if SIGEV_THREAD_ID is not set it accepts any random value. This has no real effects on the posix timer and signal delivery code, but it affects show_timer() which handles the output of /proc/$PID/timers. That function uses a string array to pretty print sigev_notify. The access to that array has no bound checks, so random sigev_notify cause access beyond the array bounds. Add proper checks for the valid notify modes and remove the SIGEV_THREAD_ID masking from various code pathes as SIGEV_NONE can never be set in combination with SIGEV_THREAD_ID. Reported-by: Eric Biggers <ebiggers3@gmail.com> Reported-by: Dmitry Vyukov <dvyukov@google.com> Reported-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: John Stultz <john.stultz@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-13module/retpoline: Warn about missing retpoline in moduleAndi Kleen1-0/+11
(cherry picked from commit caf7501a1b4ec964190f31f9c3f163de252273b8) There's a risk that a kernel which has full retpoline mitigations becomes vulnerable when a module gets loaded that hasn't been compiled with the right compiler or the right option. To enable detection of that mismatch at module load time, add a module info string "retpoline" at build time when the module was compiled with retpoline support. This only covers compiled C source, but assembler source or prebuilt object files are not checked. If a retpoline enabled kernel detects a non retpoline protected module at load time, print a warning and report it in the sysfs vulnerability file. [ tglx: Massaged changelog ] Signed-off-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: David Woodhouse <dwmw2@infradead.org> Cc: gregkh@linuxfoundation.org Cc: torvalds@linux-foundation.org Cc: jeyu@kernel.org Cc: arjan@linux.intel.com Link: https://lkml.kernel.org/r/20180125235028.31211-1-andi@firstfloor.org Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-31bpf: reject stores into ctx via st and xaddDaniel Borkmann1-0/+19
[ upstream commit f37a8cb84cce18762e8f86a70bd6a49a66ab964c ] Alexei found that verifier does not reject stores into context via BPF_ST instead of BPF_STX. And while looking at it, we also should not allow XADD variant of BPF_STX. The context rewriter is only assuming either BPF_LDX_MEM- or BPF_STX_MEM-type operations, thus reject anything other than that so that assumptions in the rewriter properly hold. Add test cases as well for BPF selftests. Fixes: d691f9e8d440 ("bpf: allow programs to write to certain skb fields") Reported-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-31bpf: fix 32-bit divide by zeroAlexei Starovoitov1-0/+18
[ upstream commit 68fda450a7df51cff9e5a4d4a4d9d0d5f2589153 ] due to some JITs doing if (src_reg == 0) check in 64-bit mode for div/mod operations mask upper 32-bits of src register before doing the check Fixes: 622582786c9e ("net: filter: x86: internal BPF JIT") Fixes: 7a12b5031c6b ("sparc64: Add eBPF JIT.") Reported-by: syzbot+48340bb518e88849e2e3@syzkaller.appspotmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-31bpf: fix divides by zeroEric Dumazet1-2/+2
[ upstream commit c366287ebd698ef5e3de300d90cd62ee9ee7373e ] Divides by zero are not nice, lets avoid them if possible. Also do_div() seems not needed when dealing with 32bit operands, but this seems a minor detail. Fixes: bd4cf0ed331a ("net: filter: rework/optimize internal BPF interpreter's instruction set") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-31bpf: arsh is not supported in 32 bit alu thus reject itDaniel Borkmann1-0/+5
[ upstream commit 7891a87efc7116590eaba57acc3c422487802c6f ] The following snippet was throwing an 'unknown opcode cc' warning in BPF interpreter: 0: (18) r0 = 0x0 2: (7b) *(u64 *)(r10 -16) = r0 3: (cc) (u32) r0 s>>= (u32) r0 4: (95) exit Although a number of JITs do support BPF_ALU | BPF_ARSH | BPF_{K,X} generation, not all of them do and interpreter does neither. We can leave existing ones and implement it later in bpf-next for the remaining ones, but reject this properly in verifier for the time being. Fixes: 17a5267067f3 ("bpf: verifier (add verifier core)") Reported-by: syzbot+93c4904c5c70348a6890@syzkaller.appspotmail.com Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-31bpf: introduce BPF_JIT_ALWAYS_ON configAlexei Starovoitov1-0/+18
[ upstream commit 290af86629b25ffd1ed6232c4e9107da031705cb ] The BPF interpreter has been used as part of the spectre 2 attack CVE-2017-5715. A quote from goolge project zero blog: "At this point, it would normally be necessary to locate gadgets in the host kernel code that can be used to actually leak data by reading from an attacker-controlled location, shifting and masking the result appropriately and then using the result of that as offset to an attacker-controlled address for a load. But piecing gadgets together and figuring out which ones work in a speculation context seems annoying. So instead, we decided to use the eBPF interpreter, which is built into the host kernel - while there is no legitimate way to invoke it from inside a VM, the presence of the code in the host kernel's text section is sufficient to make it usable for the attack, just like with ordinary ROP gadgets." To make attacker job harder introduce BPF_JIT_ALWAYS_ON config option that removes interpreter from the kernel in favor of JIT-only mode. So far eBPF JIT is supported by: x64, arm64, arm32, sparc64, s390, powerpc64, mips64 The start of JITed program is randomized and code page is marked as read-only. In addition "constant blinding" can be turned on with net.core.bpf_jit_harden v2->v3: - move __bpf_prog_ret0 under ifdef (Daniel) v1->v2: - fix init order, test_bpf and cBPF (Daniel's feedback) - fix offloaded bpf (Jakub's feedback) - add 'return 0' dummy in case something can invoke prog->bpf_func - retarget bpf tree. For bpf-next the patch would need one extra hunk. It will be sent when the trees are merged back to net-next Considered doing: int bpf_jit_enable __read_mostly = BPF_EBPF_JIT_DEFAULT; but it seems better to land the patch as-is and in bpf-next remove bpf_jit_enable global variable from all JITs, consolidate in one place and remove this jit_init() function. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-31bpf: fix bpf_tail_call() x64 JITAlexei Starovoitov1-1/+1
[ upstream commit 90caccdd8cc0215705f18b92771b449b01e2474a ] - bpf prog_array just like all other types of bpf array accepts 32-bit index. Clarify that in the comment. - fix x64 JIT of bpf_tail_call which was incorrectly loading 8 instead of 4 bytes - tighten corresponding check in the interpreter to stay consistent The JIT bug can be triggered after introduction of BPF_F_NUMA_NODE flag in commit 96eabe7a40aa in 4.14. Before that the map_flags would stay zero and though JIT code is wrong it will check bounds correctly. Hence two fixes tags. All other JITs don't have this problem. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Fixes: 96eabe7a40aa ("bpf: Allow selecting numa node during map creation") Fixes: b52f00e6a715 ("x86: bpf_jit: implement bpf_tail_call() helper") Acked-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Martin KaFai Lau <kafai@fb.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-31hrtimer: Reset hrtimer cpu base proper on CPU hotplugThomas Gleixner1-0/+3