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2019-10-05alarmtimer: Use EOPNOTSUPP instead of ENOTSUPPThadeu Lima de Souza Cascardo
commit f18ddc13af981ce3c7b7f26925f099e7c6929aba upstream. ENOTSUPP is not supposed to be returned to userspace. This was found on an OpenPower machine, where the RTC does not support set_alarm. On that system, a clock_nanosleep(CLOCK_REALTIME_ALARM, ...) results in "524 Unknown error 524" Replace it with EOPNOTSUPP which results in the expected "95 Operation not supported" error. Fixes: 1c6b39ad3f01 (alarmtimers: Return -ENOTSUPP if no RTC device is present) Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20190903171802.28314-1-cascardo@canonical.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-10-05rcu/tree: Fix SCHED_FIFO paramsPeter Zijlstra
[ Upstream commit 130d9c331bc59a8733b47c58ef197a2b1fa3ed43 ] A rather embarrasing mistake had us call sched_setscheduler() before initializing the parameters passed to it. Fixes: 1a763fd7c633 ("rcu/tree: Call setschedule() gp ktread to SCHED_FIFO outside of atomic region") Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Paul E. McKenney <paulmck@linux.ibm.com> Cc: Juri Lelli <juri.lelli@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-10-05printk: Do not lose last line in kmsg buffer dumpVincent Whitchurch
commit c9dccacfccc72c32692eedff4a27a4b0833a2afd upstream. kmsg_dump_get_buffer() is supposed to select all the youngest log messages which fit into the provided buffer. It determines the correct start index by using msg_print_text() with a NULL buffer to calculate the size of each entry. However, when performing the actual writes, msg_print_text() only writes the entry to the buffer if the written len is lesser than the size of the buffer. So if the lengths of the selected youngest log messages happen to precisely fill up the provided buffer, the last log message is not included. We don't want to modify msg_print_text() to fill up the buffer and start returning a length which is equal to the size of the buffer, since callers of its other users, such as kmsg_dump_get_line(), depend upon the current behaviour. Instead, fix kmsg_dump_get_buffer() to compensate for this. For example, with the following two final prints: [ 6.427502] AAAAAAAAAAAAA [ 6.427769] BBBBBBBB12345 A dump of a 64-byte buffer filled by kmsg_dump_get_buffer(), before this patch: 00000000: 3c 30 3e 5b 20 20 20 20 36 2e 35 32 32 31 39 37 <0>[ 6.522197 00000010: 5d 20 41 41 41 41 41 41 41 41 41 41 41 41 41 0a ] AAAAAAAAAAAAA. 00000020: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00000030: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ After this patch: 00000000: 3c 30 3e 5b 20 20 20 20 36 2e 34 35 36 36 37 38 <0>[ 6.456678 00000010: 5d 20 42 42 42 42 42 42 42 42 31 32 33 34 35 0a ] BBBBBBBB12345. 00000020: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00000030: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ Link: http://lkml.kernel.org/r/20190711142937.4083-1-vincent.whitchurch@axis.com Fixes: e2ae715d66bf4bec ("kmsg - kmsg_dump() use iterator to receive log buffer content") To: rostedt@goodmis.org Cc: linux-kernel@vger.kernel.org Cc: <stable@vger.kernel.org> # v3.5+ Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-10-05sched/psi: Correct overly pessimistic size calculationMiles Chen
[ Upstream commit 4adcdcea717cb2d8436bef00dd689aa5bc76f11b ] When passing a equal or more then 32 bytes long string to psi_write(), psi_write() copies 31 bytes to its buf and overwrites buf[30] with '\0'. Which makes the input string 1 byte shorter than it should be. Fix it by copying sizeof(buf) bytes when nbytes >= sizeof(buf). This does not cause problems in normal use case like: "some 500000 10000000" or "full 500000 10000000" because they are less than 32 bytes in length. /* assuming nbytes == 35 */ char buf[32]; buf_size = min(nbytes, (sizeof(buf) - 1)); /* buf_size = 31 */ if (copy_from_user(buf, user_buf, buf_size)) return -EFAULT; buf[buf_size - 1] = '\0'; /* buf[30] = '\0' */ Before: %cd /proc/pressure/ %echo "123456789|123456789|123456789|1234" > memory [ 22.473497] nbytes=35,buf_size=31 [ 22.473775] 123456789|123456789|123456789| (print 30 chars) %sh: write error: Invalid argument %echo "123456789|123456789|123456789|1" > memory [ 64.916162] nbytes=32,buf_size=31 [ 64.916331] 123456789|123456789|123456789| (print 30 chars) %sh: write error: Invalid argument After: %cd /proc/pressure/ %echo "123456789|123456789|123456789|1234" > memory [ 254.837863] nbytes=35,buf_size=32 [ 254.838541] 123456789|123456789|123456789|1 (print 31 chars) %sh: write error: Invalid argument %echo "123456789|123456789|123456789|1" > memory [ 9965.714935] nbytes=32,buf_size=32 [ 9965.715096] 123456789|123456789|123456789|1 (print 31 chars) %sh: write error: Invalid argument Also remove the superfluous parentheses. Signed-off-by: Miles Chen <miles.chen@mediatek.com> Cc: <linux-mediatek@lists.infradead.org> Cc: <wsd_upstream@mediatek.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20190912103452.13281-1-miles.chen@mediatek.com Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-10-05kprobes: Prohibit probing on BUG() and WARN() addressMasami Hiramatsu
[ Upstream commit e336b4027775cb458dc713745e526fa1a1996b2a ] Since BUG() and WARN() may use a trap (e.g. UD2 on x86) to get the address where the BUG() has occurred, kprobes can not do single-step out-of-line that instruction. So prohibit probing on such address. Without this fix, if someone put a kprobe on WARN(), the kernel will crash with invalid opcode error instead of outputing warning message, because kernel can not find correct bug address. Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Acked-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Cc: David S . Miller <davem@davemloft.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Naveen N . Rao <naveen.n.rao@linux.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/156750890133.19112.3393666300746167111.stgit@devnote2 Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-10-05jump_label: Don't warn on __exit jump entriesAndrew Murray
[ Upstream commit 8f35eaa5f2de020073a48ad51112237c5932cfcc ] On architectures that discard .exit.* sections at runtime, a warning is printed for each jump label that is used within an in-kernel __exit annotated function: can't patch jump_label at ehci_hcd_cleanup+0x8/0x3c WARNING: CPU: 0 PID: 1 at kernel/jump_label.c:410 __jump_label_update+0x12c/0x138 As these functions will never get executed (they are free'd along with the rest of initmem) - we do not need to patch them and should not display any warnings. The warning is displayed because the test required to satisfy jump_entry_is_init is based on init_section_contains (__init_begin to __init_end) whereas the test in __jump_label_update is based on init_kernel_text (_sinittext to _einittext) via kernel_text_address). Fixes: 19483677684b ("jump_label: Annotate entries that operate on __init code earlier") Signed-off-by: Andrew Murray <andrew.murray@arm.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Will Deacon <will@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-10-05sched/cpufreq: Align trace event behavior of fast switchingDouglas RAILLARD
[ Upstream commit 77c84dd1881d0f0176cb678d770bfbda26c54390 ] Fast switching path only emits an event for the CPU of interest, whereas the regular path emits an event for all the CPUs that had their frequency changed, i.e. all the CPUs sharing the same policy. With the current behavior, looking at cpu_frequency event for a given CPU that is using the fast switching path will not give the correct frequency signal. Signed-off-by: Douglas RAILLARD <douglas.raillard@arm.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-10-05posix-cpu-timers: Sanitize bogus WARNONSThomas Gleixner
[ Upstream commit 692117c1f7a6770ed41dd8f277cd9fed1dfb16f1 ] Warning when p == NULL and then proceeding and dereferencing p does not make any sense as the kernel will crash with a NULL pointer dereference right away. Bailing out when p == NULL and returning an error code does not cure the underlying problem which caused p to be NULL. Though it might allow to do proper debugging. Same applies to the clock id check in set_process_cpu_timer(). Clean them up and make them return without trying to do further damage. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lkml.kernel.org/r/20190819143801.846497772@linutronix.de Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-10-05idle: Prevent late-arriving interrupts from disrupting offlinePeter Zijlstra
[ Upstream commit e78a7614f3876ac649b3df608789cb6ef74d0480 ] Scheduling-clock interrupts can arrive late in the CPU-offline process, after idle entry and the subsequent call to cpuhp_report_idle_dead(). Once execution passes the call to rcu_report_dead(), RCU is ignoring the CPU, which results in lockdep complaints when the interrupt handler uses RCU: ------------------------------------------------------------------------ ============================= WARNING: suspicious RCU usage 5.2.0-rc1+ #681 Not tainted ----------------------------- kernel/sched/fair.c:9542 suspicious rcu_dereference_check() usage! other info that might help us debug this: RCU used illegally from offline CPU! rcu_scheduler_active = 2, debug_locks = 1 no locks held by swapper/5/0. stack backtrace: CPU: 5 PID: 0 Comm: swapper/5 Not tainted 5.2.0-rc1+ #681 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS Bochs 01/01/2011 Call Trace: <IRQ> dump_stack+0x5e/0x8b trigger_load_balance+0xa8/0x390 ? tick_sched_do_timer+0x60/0x60 update_process_times+0x3b/0x50 tick_sched_handle+0x2f/0x40 tick_sched_timer+0x32/0x70 __hrtimer_run_queues+0xd3/0x3b0 hrtimer_interrupt+0x11d/0x270 ? sched_clock_local+0xc/0x74 smp_apic_timer_interrupt+0x79/0x200 apic_timer_interrupt+0xf/0x20 </IRQ> RIP: 0010:delay_tsc+0x22/0x50 Code: ff 0f 1f 80 00 00 00 00 65 44 8b 05 18 a7 11 48 0f ae e8 0f 31 48 89 d6 48 c1 e6 20 48 09 c6 eb 0e f3 90 65 8b 05 fe a6 11 48 <41> 39 c0 75 18 0f ae e8 0f 31 48 c1 e2 20 48 09 c2 48 89 d0 48 29 RSP: 0000:ffff8f92c0157ed0 EFLAGS: 00000212 ORIG_RAX: ffffffffffffff13 RAX: 0000000000000005 RBX: ffff8c861f356400 RCX: ffff8f92c0157e64 RDX: 000000321214c8cc RSI: 00000032120daa7f RDI: 0000000000260f15 RBP: 0000000000000005 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000001 R12: 0000000000000000 R13: 0000000000000000 R14: ffff8c861ee18000 R15: ffff8c861ee18000 cpuhp_report_idle_dead+0x31/0x60 do_idle+0x1d5/0x200 ? _raw_spin_unlock_irqrestore+0x2d/0x40 cpu_startup_entry+0x14/0x20 start_secondary+0x151/0x170 secondary_startup_64+0xa4/0xb0 ------------------------------------------------------------------------ This happens rarely, but can be forced by happen more often by placing delays in cpuhp_report_idle_dead() following the call to rcu_report_dead(). With this in place, the following rcutorture scenario reproduces the problem within a few minutes: tools/testing/selftests/rcutorture/bin/kvm.sh --cpus 8 --duration 5 --kconfig "CONFIG_DEBUG_LOCK_ALLOC=y CONFIG_PROVE_LOCKING=y" --configs "TREE04" This commit uses the crude but effective expedient of moving the disabling of interrupts within the idle loop to precede the cpu_is_offline() check. It also invokes tick_nohz_idle_stop_tick() instead of tick_nohz_idle_stop_tick_protected() to shut off the scheduling-clock interrupt. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@kernel.org> [ paulmck: Revert tick_nohz_idle_stop_tick_protected() removal, new callers. ] Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-10-05sched/fair: Use rq_lock/unlock in online_fair_sched_groupPhil Auld
[ Upstream commit a46d14eca7b75fffe35603aa8b81df654353d80f ] Enabling WARN_DOUBLE_CLOCK in /sys/kernel/debug/sched_features causes warning to fire in update_rq_clock. This seems to be caused by onlining a new fair sched group not using the rq lock wrappers. [] rq->clock_update_flags & RQCF_UPDATED [] WARNING: CPU: 5 PID: 54385 at kernel/sched/core.c:210 update_rq_clock+0xec/0x150 [] Call Trace: [] online_fair_sched_group+0x53/0x100 [] cpu_cgroup_css_online+0x16/0x20 [] online_css+0x1c/0x60 [] cgroup_apply_control_enable+0x231/0x3b0 [] cgroup_mkdir+0x41b/0x530 [] kernfs_iop_mkdir+0x61/0xa0 [] vfs_mkdir+0x108/0x1a0 [] do_mkdirat+0x77/0xe0 [] do_syscall_64+0x55/0x1d0 [] entry_SYSCALL_64_after_hwframe+0x44/0xa9 Using the wrappers in online_fair_sched_group instead of the raw locking removes this warning. [ tglx: Use rq_*lock_irq() ] Signed-off-by: Phil Auld <pauld@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Vincent Guittot <vincent.guittot@linaro.org> Cc: Ingo Molnar <mingo@kernel.org> Link: https://lkml.kernel.org/r/20190801133749.11033-1-pauld@redhat.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-10-05rcu: Add destroy_work_on_stack() to match INIT_WORK_ONSTACK()Paul E. McKenney
[ Upstream commit fbad01af8c3bb9618848abde8054ab7e0c2330fe ] The synchronize_rcu_expedited() function has an INIT_WORK_ONSTACK(), but lacks the corresponding destroy_work_on_stack(). This commit therefore adds destroy_work_on_stack(). Reported-by: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com> Acked-by: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-10-05rcu/tree: Call setschedule() gp ktread to SCHED_FIFO outside of atomic regionJuri Lelli
[ Upstream commit 1a763fd7c6335e3122c1cc09576ef6c99ada4267 ] sched_setscheduler() needs to acquire cpuset_rwsem, but it is currently called from an invalid (atomic) context by rcu_spawn_gp_kthread(). Fix that by simply moving sched_setscheduler_nocheck() call outside of the atomic region, as it doesn't actually require to be guarded by rcu_node lock. Suggested-by: Peter Zijlstra <peterz@infradead.org> Tested-by: Dietmar Eggemann <dietmar.eggemann@arm.com> Signed-off-by: Juri Lelli <juri.lelli@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: bristot@redhat.com Cc: claudio@evidence.eu.com Cc: lizefan@huawei.com Cc: longman@redhat.com Cc: luca.abeni@santannapisa.it Cc: mathieu.poirier@linaro.org Cc: rostedt@goodmis.org Cc: tj@kernel.org Cc: tommaso.cucinotta@santannapisa.it Link: https://lkml.kernel.org/r/20190719140000.31694-8-juri.lelli@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-10-05sched/deadline: Fix bandwidth accounting at all levels after offline migrationJuri Lelli
[ Upstream commit 59d06cea1198d665ba11f7e8c5f45b00ff2e4812 ] If a task happens to be throttled while the CPU it was running on gets hotplugged off, the bandwidth associated with the task is not correctly migrated with it when the replenishment timer fires (offline_migration). Fix things up, for this_bw, running_bw and total_bw, when replenishment timer fires and task is migrated (dl_task_offline_migration()). Tested-by: Dietmar Eggemann <dietmar.eggemann@arm.com> Signed-off-by: Juri Lelli <juri.lelli@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: bristot@redhat.com Cc: claudio@evidence.eu.com Cc: lizefan@huawei.com Cc: longman@redhat.com Cc: luca.abeni@santannapisa.it Cc: mathieu.poirier@linaro.org Cc: rostedt@goodmis.org Cc: tj@kernel.org Cc: tommaso.cucinotta@santannapisa.it Link: https://lkml.kernel.org/r/20190719140000.31694-5-juri.lelli@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-10-05sched/core: Fix CPU controller for !RT_GROUP_SCHEDJuri Lelli
[ Upstream commit a07db5c0865799ebed1f88be0df50c581fb65029 ] On !CONFIG_RT_GROUP_SCHED configurations it is currently not possible to move RT tasks between cgroups to which CPU controller has been attached; but it is oddly possible to first move tasks around and then make them RT (setschedule to FIFO/RR). E.g.: # mkdir /sys/fs/cgroup/cpu,cpuacct/group1 # chrt -fp 10 $$ # echo $$ > /sys/fs/cgroup/cpu,cpuacct/group1/tasks bash: echo: write error: Invalid argument # chrt -op 0 $$ # echo $$ > /sys/fs/cgroup/cpu,cpuacct/group1/tasks # chrt -fp 10 $$ # cat /sys/fs/cgroup/cpu,cpuacct/group1/tasks 2345 2598 # chrt -p 2345 pid 2345's current scheduling policy: SCHED_FIFO pid 2345's current scheduling priority: 10 Also, as Michal noted, it is currently not possible to enable CPU controller on unified hierarchy with !CONFIG_RT_GROUP_SCHED (if there are any kernel RT threads in root cgroup, they can't be migrated to the newly created CPU controller's root in cgroup_update_dfl_csses()). Existing code comes with a comment saying the "we don't support RT-tasks being in separate groups". Such comment is however stale and belongs to pre-RT_GROUP_SCHED times. Also, it doesn't make much sense for !RT_GROUP_ SCHED configurations, since checks related to RT bandwidth are not performed at all in these cases. Make moving RT tasks between CPU controller groups viable by removing special case check for RT (and DEADLINE) tasks. Signed-off-by: Juri Lelli <juri.lelli@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Michal Koutný <mkoutny@suse.com> Reviewed-by: Daniel Bristot de Oliveira <bristot@redhat.com> Acked-by: Tejun Heo <tj@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: lizefan@huawei.com Cc: longman@redhat.com Cc: luca.abeni@santannapisa.it Cc: rostedt@goodmis.org Link: https://lkml.kernel.org/r/20190719063455.27328-1-juri.lelli@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-10-05sched/fair: Fix imbalance due to CPU affinityVincent Guittot
[ Upstream commit f6cad8df6b30a5d2bbbd2e698f74b4cafb9fb82b ] The load_balance() has a dedicated mecanism to detect when an imbalance is due to CPU affinity and must be handled at parent level. In this case, the imbalance field of the parent's sched_group is set. The description of sg_imbalanced() gives a typical example of two groups of 4 CPUs each and 4 tasks each with a cpumask covering 1 CPU of the first group and 3 CPUs of the second group. Something like: { 0 1 2 3 } { 4 5 6 7 } * * * * But the load_balance fails to fix this UC on my octo cores system made of 2 clusters of quad cores. Whereas the load_balance is able to detect that the imbalanced is due to CPU affinity, it fails to fix it because the imbalance field is cleared before letting parent level a chance to run. In fact, when the imbalance is detected, the load_balance reruns without the CPU with pinned tasks. But there is no other running tasks in the situation described above and everything looks balanced this time so the imbalance field is immediately cleared. The imbalance field should not be cleared if there is no other task to move when the imbalance is detected. Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/1561996022-28829-1-git-send-email-vincent.guittot@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-10-05time/tick-broadcast: Fix tick_broadcast_offline() lockdep complaintPaul E. McKenney
[ Upstream commit 84ec3a0787086fcd25f284f59b3aa01fd6fc0a5d ] time/tick-broadcast: Fix tick_broadcast_offline() lockdep complaint The TASKS03 and TREE04 rcutorture scenarios produce the following lockdep complaint: WARNING: inconsistent lock state 5.2.0-rc1+ #513 Not tainted -------------------------------- inconsistent {IN-HARDIRQ-W} -> {HARDIRQ-ON-W} usage. migration/1/14 [HC0[0]:SC0[0]:HE1:SE1] takes: (____ptrval____) (tick_broadcast_lock){?...}, at: tick_broadcast_offline+0xf/0x70 {IN-HARDIRQ-W} state was registered at: lock_acquire+0xb0/0x1c0 _raw_spin_lock_irqsave+0x3c/0x50 tick_broadcast_switch_to_oneshot+0xd/0x40 tick_switch_to_oneshot+0x4f/0xd0 hrtimer_run_queues+0xf3/0x130 run_local_timers+0x1c/0x50 update_process_times+0x1c/0x50 tick_periodic+0x26/0xc0 tick_handle_periodic+0x1a/0x60 smp_apic_timer_interrupt+0x80/0x2a0 apic_timer_interrupt+0xf/0x20 _raw_spin_unlock_irqrestore+0x4e/0x60 rcu_nocb_gp_kthread+0x15d/0x590 kthread+0xf3/0x130 ret_from_fork+0x3a/0x50 irq event stamp: 171 hardirqs last enabled at (171): [<ffffffff8a201a37>] trace_hardirqs_on_thunk+0x1a/0x1c hardirqs last disabled at (170): [<ffffffff8a201a53>] trace_hardirqs_off_thunk+0x1a/0x1c softirqs last enabled at (0): [<ffffffff8a264ee0>] copy_process.part.56+0x650/0x1cb0 softirqs last disabled at (0): [<0000000000000000>] 0x0 [...] To reproduce, run the following rcutorture test: $ tools/testing/selftests/rcutorture/bin/kvm.sh --duration 5 --kconfig "CONFIG_DEBUG_LOCK_ALLOC=y CONFIG_PROVE_LOCKING=y" --configs "TASKS03 TREE04" It turns out that tick_broadcast_offline() was an innocent bystander. After all, interrupts are supposed to be disabled throughout take_cpu_down(), and therefore should have been disabled upon entry to tick_offline_cpu() and thus to tick_broadcast_offline(). This suggests that one of the CPU-hotplug notifiers was incorrectly enabling interrupts, and leaving them enabled on return. Some debugging code showed that the culprit was sched_cpu_dying(). It had irqs enabled after return from sched_tick_stop(). Which in turn had irqs enabled after return from cancel_delayed_work_sync(). Which is a wrapper around __cancel_work_timer(). Which can sleep in the case where something else is concurrently trying to cancel the same delayed work, and as Thomas Gleixner pointed out on IRC, sleeping is a decidedly bad idea when you are invoked from take_cpu_down(), regardless of the state you leave interrupts in upon return. Code inspection located no reason why the delayed work absolutely needed to be canceled from sched_tick_stop(): The work is not bound to the outgoing CPU by design, given that the whole point is to collect statistics without disturbing the outgoing CPU. This commit therefore simply drops the cancel_delayed_work_sync() from sched_tick_stop(). Instead, a new ->state field is added to the tick_work structure so that the delayed-work handler function sched_tick_remote() can avoid reposting itself. A cpu_is_offline() check is also added to sched_tick_remote() to avoid mucking with the state of an offlined CPU (though it does appear safe to do so). The sched_tick_start() and sched_tick_stop() functions also update ->state, and sched_tick_start() also schedules the delayed work if ->state indicates that it is not already in flight. Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com> [ paulmck: Apply Peter Zijlstra and Frederic Weisbecker atomics feedback. ] Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20190625165238.GJ26519@linux.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-09-14Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netLinus Torvalds
Pull networking fixes from David Miller: 1) Don't corrupt xfrm_interface parms before validation, from Nicolas Dichtel. 2) Revert use of usb-wakeup in btusb, from Mario Limonciello. 3) Block ipv6 packets in bridge netfilter if ipv6 is disabled, from Leonardo Bras. 4) IPS_OFFLOAD not honored in ctnetlink, from Pablo Neira Ayuso. 5) Missing ULP check in sock_map, from John Fastabend. 6) Fix receive statistic handling in forcedeth, from Zhu Yanjun. 7) Fix length of SKB allocated in 6pack driver, from Christophe JAILLET. 8) ip6_route_info_create() returns an error pointer, not NULL. From Maciej Żenczykowski. 9) Only add RDS sock to the hashes after rs_transport is set, from Ka-Cheong Poon. 10) Don't double clean TX descriptors in ixgbe, from Ilya Maximets. 11) Presence of transmit IPSEC offload in an SKB is not tested for correctly in ixgbe and ixgbevf. From Steffen Klassert and Jeff Kirsher. 12) Need rcu_barrier() when register_netdevice() takes one of the notifier based failure paths, from Subash Abhinov Kasiviswanathan. 13) Fix leak in sctp_do_bind(), from Mao Wenan. * git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (72 commits) cdc_ether: fix rndis support for Mediatek based smartphones sctp: destroy bucket if failed to bind addr sctp: remove redundant assignment when call sctp_get_port_local sctp: change return type of sctp_get_port_local ixgbevf: Fix secpath usage for IPsec Tx offload sctp: Fix the link time qualifier of 'sctp_ctrlsock_exit()' ixgbe: Fix secpath usage for IPsec TX offload. net: qrtr: fix memort leak in qrtr_tun_write_iter net: Fix null de-reference of device refcount ipv6: Fix the link time qualifier of 'ping_v6_proc_exit_net()' tun: fix use-after-free when register netdev failed tcp: fix tcp_ecn_withdraw_cwr() to clear TCP_ECN_QUEUE_CWR ixgbe: fix double clean of Tx descriptors with xdp ixgbe: Prevent u8 wrapping of ITR value to something less than 10us mlx4: fix spelling mistake "veify" -> "verify" net: hns3: fix spelling mistake "undeflow" -> "underflow" net: lmc: fix spelling mistake "runnin" -> "running" NFC: st95hf: fix spelling mistake "receieve" -> "receive" net/rds: An rds_sock is added too early to the hash table mac80211: Do not send Layer 2 Update frame before authorization ...
2019-09-12cgroup: freezer: fix frozen state inheritanceRoman Gushchin
If a new child cgroup is created in the frozen cgroup hierarchy (one or more of ancestor cgroups is frozen), the CGRP_FREEZE cgroup flag should be set. Otherwise if a process will be attached to the child cgroup, it won't become frozen. The problem can be reproduced with the test_cgfreezer_mkdir test. This is the output before this patch: ~/test_freezer ok 1 test_cgfreezer_simple ok 2 test_cgfreezer_tree ok 3 test_cgfreezer_forkbomb Cgroup /sys/fs/cgroup/cg_test_mkdir_A/cg_test_mkdir_B isn't frozen not ok 4 test_cgfreezer_mkdir ok 5 test_cgfreezer_rmdir ok 6 test_cgfreezer_migrate ok 7 test_cgfreezer_ptrace ok 8 test_cgfreezer_stopped ok 9 test_cgfreezer_ptraced ok 10 test_cgfreezer_vfork And with this patch: ~/test_freezer ok 1 test_cgfreezer_simple ok 2 test_cgfreezer_tree ok 3 test_cgfreezer_forkbomb ok 4 test_cgfreezer_mkdir ok 5 test_cgfreezer_rmdir ok 6 test_cgfreezer_migrate ok 7 test_cgfreezer_ptrace ok 8 test_cgfreezer_stopped ok 9 test_cgfreezer_ptraced ok 10 test_cgfreezer_vfork Reported-by: Mark Crossen <mcrossen@fb.com> Signed-off-by: Roman Gushchin <guro@fb.com> Fixes: 76f969e8948d ("cgroup: cgroup v2 freezer") Cc: Tejun Heo <tj@kernel.org> Cc: stable@vger.kernel.org # v5.2+ Signed-off-by: Tejun Heo <tj@kernel.org>
2019-09-12Merge tag 'for-linus-20190912' of ↵Linus Torvalds
gitolite.kernel.org:pub/scm/linux/kernel/git/brauner/linux Pull clone3 fix from Christian Brauner: "This is a last-minute bugfix for clone3() that should go in before we release 5.3 with clone3(). clone3() did not verify that the exit_signal argument was set to a valid signal. This can be used to cause a crash by specifying a signal greater than NSIG. e.g. -1. The commit from Eugene adds a check to copy_clone_args_from_user() to verify that the exit signal is limited by CSIGNAL as with legacy clone() and that the signal is valid. With this we don't get the legacy clone behavior were an invalid signal could be handed down and would only be detected and then ignored in do_notify_parent(). Users of clone3() will now get a proper error right when they pass an invalid exit signal. Note, that this is not a change in user-visible behavior since no kernel with clone3() has been released yet" * tag 'for-linus-20190912' of gitolite.kernel.org:pub/scm/linux/kernel/git/brauner/linux: fork: block invalid exit signals with clone3()
2019-09-12fork: block invalid exit signals with clone3()Eugene Syromiatnikov
Previously, higher 32 bits of exit_signal fields were lost when copied to the kernel args structure (that uses int as a type for the respective field). Moreover, as Oleg has noted, exit_signal is used unchecked, so it has to be checked for sanity before use; for the legacy syscalls, applying CSIGNAL mask guarantees that it is at least non-negative; however, there's no such thing is done in clone3() code path, and that can break at least thread_group_leader. This commit adds a check to copy_clone_args_from_user() to verify that the exit signal is limited by CSIGNAL as with legacy clone() and that the signal is valid. With this we don't get the legacy clone behavior were an invalid signal could be handed down and would only be detected and ignored in do_notify_parent(). Users of clone3() will now get a proper error when they pass an invalid exit signal. Note, that this is not user-visible behavior since no kernel with clone3() has been released yet. The following program will cause a splat on a non-fixed clone3() version and will fail correctly on a fixed version: #define _GNU_SOURCE #include <linux/sched.h> #include <linux/types.h> #include <sched.h> #include <stdio.h> #include <stdlib.h> #include <sys/syscall.h> #include <sys/wait.h> #include <unistd.h> int main(int argc, char *argv[]) { pid_t pid = -1; struct clone_args args = {0}; args.exit_signal = -1; pid = syscall(__NR_clone3, &args, sizeof(struct clone_args)); if (pid < 0) exit(EXIT_FAILURE); if (pid == 0) exit(EXIT_SUCCESS); wait(NULL); exit(EXIT_SUCCESS); } Fixes: 7f192e3cd316 ("fork: add clone3") Reported-by: Oleg Nesterov <oleg@redhat.com> Suggested-by: Oleg Nesterov <oleg@redhat.com> Suggested-by: Dmitry V. Levin <ldv@altlinux.org> Signed-off-by: Eugene Syromiatnikov <esyr@redhat.com> Link: https://lore.kernel.org/r/4b38fa4ce420b119a4c6345f42fe3cec2de9b0b5.1568223594.git.esyr@redhat.com [christian.brauner@ubuntu.com: simplify check and rework commit message] Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
2019-09-12Merge branch 'perf-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf fix from Ingo Molnar: "Fix an initialization bug in the hw-breakpoints, which triggered on the ARM platform" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf/hw_breakpoint: Fix arch_hw_breakpoint use-before-initialization
2019-09-12Merge branch 'irq-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull irq fix from Ingo Molnar: "Fix a race in the IRQ resend mechanism, which can result in a NULL dereference crash" * 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: genirq: Prevent NULL pointer dereference in resend_irqs()
2019-09-06perf/hw_breakpoint: Fix arch_hw_breakpoint use-before-initializationMark-PK Tsai
If we disable the compiler's auto-initialization feature, if -fplugin-arg-structleak_plugin-byref or -ftrivial-auto-var-init=pattern are disabled, arch_hw_breakpoint may be used before initialization after: 9a4903dde2c86 ("perf/hw_breakpoint: Split attribute parse and commit") On our ARM platform, the struct step_ctrl in arch_hw_breakpoint, which used to be zero-initialized by kzalloc(), may be used in arch_install_hw_breakpoint() without initialization. Signed-off-by: Mark-PK Tsai <mark-pk.tsai@mediatek.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Alix Wu <alix.wu@mediatek.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: YJ Chiang <yj.chiang@mediatek.com> Link: https://lkml.kernel.org/r/20190906060115.9460-1-mark-pk.tsai@mediatek.com [ Minor edits. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-09-05genirq: Prevent NULL pointer dereference in resend_irqs()Yunfeng Ye
The following crash was observed: Unable to handle kernel NULL pointer dereference at 0000000000000158 Internal error: Oops: 96000004 [#1] SMP pc : resend_irqs+0x68/0xb0 lr : resend_irqs+0x64/0xb0 ... Call trace: resend_irqs+0x68/0xb0 tasklet_action_common.isra.6+0x84/0x138 tasklet_action+0x2c/0x38 __do_softirq+0x120/0x324 run_ksoftirqd+0x44/0x60 smpboot_thread_fn+0x1ac/0x1e8 kthread+0x134/0x138 ret_from_fork+0x10/0x18 The reason for this is that the interrupt resend mechanism happens in soft interrupt context, which is a asynchronous mechanism versus other operations on interrupts. free_irq() does not take resend handling into account. Thus, the irq descriptor might be already freed before the resend tasklet is executed. resend_irqs() does not check the return value of the interrupt descriptor lookup and derefences the return value unconditionally. 1): __setup_irq irq_startup check_irq_resend // activate softirq to handle resend irq 2): irq_domain_free_irqs irq_free_descs free_desc call_rcu(&desc->rcu, delayed_free_desc) 3): __do_softirq tasklet_action resend_irqs desc = irq_to_desc(irq) desc->handle_irq(desc) // desc is NULL --> Ooops Fix this by adding a NULL pointer check in resend_irqs() before derefencing the irq descriptor. Fixes: a4633adcdbc1 ("[PATCH] genirq: add genirq sw IRQ-retrigger") Signed-off-by: Yunfeng Ye <yeyunfeng@huawei.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Zhiqiang Liu <liuzhiqiang26@huawei.com> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/1630ae13-5c8e-901e-de09-e740b6a426a7@huawei.com
2019-09-05bpf: fix precision tracking of stack slotsAlexei Starovoitov
The problem can be seen in the following two tests: 0: (bf) r3 = r10 1: (55) if r3 != 0x7b goto pc+0 2: (7a) *(u64 *)(r3 -8) = 0 3: (79) r4 = *(u64 *)(r10 -8) .. 0: (85) call bpf_get_prandom_u32#7 1: (bf) r3 = r10 2: (55) if r3 != 0x7b goto pc+0 3: (7b) *(u64 *)(r3 -8) = r0 4: (79) r4 = *(u64 *)(r10 -8) When backtracking need to mark R4 it will mark slot fp-8. But ST or STX into fp-8 could belong to the same block of instructions. When backtracing is done the parent state may have fp-8 slot as "unallocated stack". Which will cause verifier to warn and incorrectly reject such programs. Writes into stack via non-R10 register are rare. llvm always generates canonical stack spill/fill. For such pathological case fall back to conservative precision tracking instead of rejecting. Reported-by: syzbot+c8d66267fd2b5955287e@syzkaller.appspotmail.com Fixes: b5dc0163d8fd ("bpf: precise scalar_value tracking") Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-09-04sched/core: Fix uclamp ABI bug, clean up and robustify sched_read_attr() ABI ↵Ingo Molnar
logic and code Thadeu Lima de Souza Cascardo reported that 'chrt' broke on recent kernels: $ chrt -p $$ chrt: failed to get pid 26306's policy: Argument list too long and he has root-caused the bug to the following commit increasing sched_attr size and breaking sched_read_attr() into returning -EFBIG: a509a7cd7974 ("sched/uclamp: Extend sched_setattr() to support utilization clamping") The other, bigger bug is that the whole sched_getattr() and sched_read_attr() logic of checking non-zero bits in new ABI components is arguably broken, and pretty much any extension of the ABI will spuriously break the ABI. That's way too fragile. Instead implement the perf syscall's extensible ABI instead, which we already implement on the sched_setattr() side: - if user-attributes have the same size as kernel attributes then the logic is unchanged. - if user-attributes are larger than the kernel knows about then simply skip the extra bits, but set attr->size to the (smaller) kernel size so that tooling can (in principle) handle older kernel as well. - if user-attributes are smaller than the kernel knows about then just copy whatever user-space can accept. Also clean up the whole logic: - Simplify the code flow - there's no need for 'ret' for example. - Standardize on 'kattr/uattr' and 'ksize/usize' naming to make sure we always know which side we are dealing with. - Why is it called 'read' when what it does is to copy to user? This code is so far away from VFS read() semantics that the naming is actively confusing. Name it sched_attr_copy_to_user() instead, which mirrors other copy_to_user() functionality. - Move the attr->size assignment from the head of sched_getattr() to the sched_attr_copy_to_user() function. Nothing else within the kernel should care about the size of the structure. With these fixes the sched_getattr() syscall now nicely supports an extensible ABI in both a forward and backward compatible fashion, and will also fix the chrt bug. As an added bonus the bogus -EFBIG return is removed as well, which as Thadeu noted should have been -E2BIG to begin with. Reported-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com> Tested-by: Dietmar Eggemann <dietmar.eggemann@arm.com> Tested-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com> Acked-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Patrick Bellasi <patrick.bellasi@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: a509a7cd7974 ("sched/uclamp: Extend sched_setattr() to support utilization clamping") Link: https://lkml.kernel.org/r/20190904075532.GA26751@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-09-03sched/fair: Don't assign runtime for throttled cfs_rqLiangyan
do_sched_cfs_period_timer() will refill cfs_b runtime and call distribute_cfs_runtime to unthrottle cfs_rq, sometimes cfs_b->runtime will allocate all quota to one cfs_rq incorrectly, then other cfs_rqs attached to this cfs_b can't get runtime and will be throttled. We find that one throttled cfs_rq has non-negative cfs_rq->runtime_remaining and cause an unexpetced cast from s64 to u64 in snippet: distribute_cfs_runtime() { runtime = -cfs_rq->runtime_remaining + 1; } The runtime here will change to a large number and consume all cfs_b->runtime in this cfs_b period. According to Ben Segall, the throttled cfs_rq can have account_cfs_rq_runtime called on it because it is throttled before idle_balance, and the idle_balance calls update_rq_clock to add time that is accounted to the task. This commit prevents cfs_rq to be assgined new runtime if it has been throttled until that distribute_cfs_runtime is called. Signed-off-by: Liangyan <liangyan.peng@linux.alibaba.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Valentin Schneider <valentin.schneider@arm.com> Reviewed-by: Ben Segall <bsegall@google.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: shanpeic@linux.alibaba.com Cc: stable@vger.kernel.org Cc: xlpang@linux.alibaba.com Fixes: d3d9dc330236 ("sched: Throttle entities exceeding their allowed bandwidth") Link: https://lkml.kernel.org/r/20190826121633.6538-1-liangyan.peng@linux.alibaba.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-09-01Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netLinus Torvalds
Pull networking fixes from David Miller: 1) Fix some length checks during OGM processing in batman-adv, from Sven Eckelmann. 2) Fix regression that caused netfilter conntrack sysctls to not be per-netns any more. From Florian Westphal. 3) Use after free in netpoll, from Feng Sun. 4) Guard destruction of pfifo_fast per-cpu qdisc stats with qdisc_is_percpu_stats(), from Davide Caratti. Similar bug is fixed in pfifo_fast_enqueue(). 5) Fix memory leak in mld_del_delrec(), from Eric Dumazet. 6) Handle neigh events on internal ports correctly in nfp, from John Hurley. 7) Clear SKB timestamp in NF flow table code so that it does not confuse fq scheduler. From Florian Westphal. 8) taprio destroy can crash if it is invoked in a failure path of taprio_init(), because the list head isn't setup properly yet and the list del is unconditional. Perform the list add earlier to address this. From Vladimir Oltean. 9) Make sure to reapply vlan filters on device up, in aquantia driver. From Dmitry Bogdanov. 10) sgiseeq driver releases DMA memory using free_page() instead of dma_free_attrs(). From Christophe JAILLET. * git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (58 commits) net: seeq: Fix the function used to release some memory in an error handling path enetc: Add missing call to 'pci_free_irq_vectors()' in probe and remove functions net: bcmgenet: use ethtool_op_get_ts_info() tc-testing: don't hardcode 'ip' in nsPlugin.py net: dsa: microchip: add KSZ8563 compatibility string dt-bindings: net: dsa: document additional Microchip KSZ8563 switch net: aquantia: fix out of memory condition on rx side net: aquantia: linkstate irq should be oneshot net: aquantia: reapply vlan filters on up net: aquantia: fix limit of vlan filters net: aquantia: fix removal of vlan 0 net/sched: cbs: Set default link speed to 10 Mbps in cbs_set_port_rate taprio: Set default link speed to 10 Mbps in taprio_set_picos_per_byte taprio: Fix kernel panic in taprio_destroy net: dsa: microchip: fill regmap_config name rxrpc: Fix lack of conn cleanup when local endpoint is cleaned up [ver #2] net: stmmac: dwmac-rk: Don't fail if phy regulator is absent amd-xgbe: Fix error path in xgbe_mod_init() netfilter: nft_meta_bridge: Fix get NFT_META_BRI_IIFVPROTO in network byteorder mac80211: Correctly set noencrypt for PAE frames ...
2019-08-31Merge tag 'trace-v5.3-rc6' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing fixes from Steven Rostedt: "Small fixes and minor cleanups for tracing: - Make exported ftrace function not static - Fix NULL pointer dereference in reading probes as they are created - Fix NULL pointer dereference in k/uprobe clean up path - Various documentation fixes" * tag 'trace-v5.3-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: tracing: Correct kdoc formats ftrace/x86: Remove mcount() declaration tracing/probe: Fix null pointer dereference tracing: Make exported ftrace_set_clr_event non-static ftrace: Check for successful allocation of hash ftrace: Check for empty hash and comment the race with registering probes ftrace: Fix NULL pointer dereference in t_probe_next()
2019-08-31tracing: Correct kdoc formatsJakub Kicinski
Fix the following kdoc warnings: kernel/trace/trace.c:1579: warning: Function parameter or member 'tr' not described in 'update_max_tr_single' kernel/trace/trace.c:1579: warning: Function parameter or member 'tsk' not described in 'update_max_tr_single' kernel/trace/trace.c:1579: warning: Function parameter or member 'cpu' not described in 'update_max_tr_single' kernel/trace/trace.c:1776: warning: Function parameter or member 'type' not described in 'register_tracer' kernel/trace/trace.c:2239: warning: Function parameter or member 'task' not described in 'tracing_record_taskinfo' kernel/trace/trace.c:2239: warning: Function parameter or member 'flags' not described in 'tracing_record_taskinfo' kernel/trace/trace.c:2269: warning: Function parameter or member 'prev' not described in 'tracing_record_taskinfo_sched_switch' kernel/trace/trace.c:2269: warning: Function parameter or member 'next' not described in 'tracing_record_taskinfo_sched_switch' kernel/trace/trace.c:2269: warning: Function parameter or member 'flags' not described in 'tracing_record_taskinfo_sched_switch' kernel/trace/trace.c:3078: warning: Function parameter or member 'ip' not described in 'trace_vbprintk' kernel/trace/trace.c:3078: warning: Function parameter or member 'fmt' not described in 'trace_vbprintk' kernel/trace/trace.c:3078: warning: Function parameter or member 'args' not described in 'trace_vbprintk' Link: http://lkml.kernel.org/r/20190828052549.2472-2-jakub.kicinski@netronome.com Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-08-31tracing/probe: Fix null pointer dereferenceXinpeng Liu
BUG: KASAN: null-ptr-deref in trace_probe_cleanup+0x8d/0xd0 Read of size 8 at addr 0000000000000000 by task syz-executor.0/9746 trace_probe_cleanup+0x8d/0xd0 free_trace_kprobe.part.14+0x15/0x50 alloc_trace_kprobe+0x23e/0x250 Link: http://lkml.kernel.org/r/1565220563-980-1-git-send-email-danielliu861@gmail.com Fixes: e3dc9f898ef9c ("tracing/probe: Add trace_event_call accesses APIs") Signed-off-by: Xinpeng Liu <danielliu861@gmail.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-08-31tracing: Make exported ftrace_set_clr_event non-staticDenis Efremov
The function ftrace_set_clr_event is declared static and marked EXPORT_SYMBOL_GPL(), which is at best an odd combination. Because the function was decided to be a part of API, this commit removes the static attribute and adds the declaration to the header. Link: http://lkml.kernel.org/r/20190704172110.27041-1-efremov@linux.com Fixes: f45d1225adb04 ("tracing: Kernel access to Ftrace instances") Reviewed-by: Joe Jin <joe.jin@oracle.com> Signed-off-by: Denis Efremov <efremov@linux.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-08-30Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpfDavid S. Miller
Daniel Borkmann says: ==================== pull-request: bpf 2019-08-31 The following pull-request contains BPF updates for your *net* tree. The main changes are: 1) Fix 32-bit zero-extension during constant blinding which has been causing a regression on ppc64, from Naveen. 2) Fix a latency bug in nfp driver when updating stack index register, from Jiong. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2019-08-30ftrace: Check for successful allocation of hashNaveen N. Rao
In register_ftrace_function_probe(), we are not checking the return value of alloc_and_copy_ftrace_hash(). The subsequent call to ftrace_match_records() may end up dereferencing the same. Add a check to ensure this doesn't happen. Link: http://lkml.kernel.org/r/26e92574f25ad23e7cafa3cf5f7a819de1832cbe.1562249521.git.naveen.n.rao@linux.vnet.ibm.com Cc: stable@vger.kernel.org Fixes: 1ec3a81a0cf42 ("ftrace: Have each function probe use its own ftrace_ops") Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-08-30ftrace: Check for empty hash and comment the race with registering probesSteven Rostedt (VMware)
The race between adding a function probe and reading the probes that exist is very subtle. It needs a comment. Also, the issue can also happen if the probe has has the EMPTY_HASH as its func_hash. Cc: stable@vger.kernel.org Fixes: 7b60f3d876156 ("ftrace: Dynamically create the probe ftrace_ops for the trace_array") Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-08-30ftrace: Fix NULL pointer dereference in t_probe_next()Naveen N. Rao
LTP testsuite on powerpc results in the below crash: Unable to handle kernel paging request for data at address 0x00000000 Faulting instruction address: 0xc00000000029d800 Oops: Kernel access of bad area, sig: 11 [#1] LE SMP NR_CPUS=2048 NUMA PowerNV ... CPU: 68 PID: 96584 Comm: cat Kdump: loaded Tainted: G W NIP: c00000000029d800 LR: c00000000029dac4 CTR: c0000000001e6ad0 REGS: c0002017fae8ba10 TRAP: 0300 Tainted: G W MSR: 9000000000009033 <SF,HV,EE,ME,IR,DR,RI,LE> CR: 28022422 XER: 20040000 CFAR: c00000000029d90c DAR: 0000000000000000 DSISR: 40000000 IRQMASK: 0 ... NIP [c00000000029d800] t_probe_next+0x60/0x180 LR [c00000000029dac4] t_mod_start+0x1a4/0x1f0 Call Trace: [c0002017fae8bc90] [c000000000cdbc40] _cond_resched+0x10/0xb0 (unreliable) [c0002017fae8bce0] [c0000000002a15b0] t_start+0xf0/0x1c0 [c0002017fae8bd30] [c0000000004ec2b4] seq_read+0x184/0x640 [c0002017fae8bdd0] [c0000000004a57bc] sys_read+0x10c/0x300 [c0002017fae8be30] [c00000000000b388] system_call+0x5c/0x70 The test (ftrace_set_ftrace_filter.sh) is part of ftrace stress tests and the crash happens when the test does 'cat $TRACING_PATH/set_ftrace_filter'. The address points to the second line below, in t_probe_next(), where filter_hash is dereferenced: hash = iter->probe->ops.func_hash->filter_hash; size = 1 << hash->size_bits; This happens due to a race with register_ftrace_function_probe(). A new ftrace_func_probe is created and added into the func_probes list in trace_array under ftrace_lock. However, before initializing the filter, we drop ftrace_lock, and re-acquire it after acquiring regex_lock. If another process is trying to read set_ftrace_filter, it will be able to acquire ftrace_lock during this window and it will end up seeing a NULL filter_hash. Fix this by just checking for a NULL filter_hash in t_probe_next(). If the filter_hash is NULL, then this probe is just being added and we can simply return from here. Link: http://lkml.kernel.org/r/05e021f757625cbbb006fad41380323dbe4e3b43.1562249521.git.naveen.n.rao@linux.vnet.ibm.com Cc: stable@vger.kernel.org Fixes: 7b60f3d876156 ("ftrace: Dynamically create the probe ftrace_ops for the trace_array") Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-08-28Merge tag 'arm64-fixes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux Pull arm64 fixes from Will Deacon: "Hot on the heels of our last set of fixes are a few more for -rc7. Two of them are fixing issues with our virtual interrupt controller implementation in KVM/arm, while the other is a longstanding but straightforward kallsyms fix which was been acked by Masami and resolves an initialisation failure in kprobes observed on arm64. - Fix GICv2 emulation bug (KVM) - Fix deadlock in virtual GIC interrupt injection code (KVM) - Fix kprobes blacklist init failure due to broken kallsyms lookup" * tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: KVM: arm/arm64: vgic-v2: Handle SGI bits in GICD_I{S,C}PENDR0 as WI KVM: arm/arm64: vgic: Fix potential deadlock when ap_list is long kallsyms: Don't let kallsyms_lookup_size_offset() fail on retrieving the first symbol
2019-08-27Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netLinus Torvalds
Pull networking fixes from David Miller: 1) Use 32-bit index for tails calls in s390 bpf JIT, from Ilya Leoshkevich. 2) Fix missed EPOLLOUT events in TCP, from Eric Dumazet. Same fix for SMC from Jason Baron. 3) ipv6_mc_may_pull() should return 0 for malformed packets, not -EINVAL. From Stefano Brivio. 4) Don't forget to unpin umem xdp pages in error path of xdp_umem_reg(). From Ivan Khoronzhuk. 5) Fix sta object leak in mac80211, from Johannes Berg. 6) Fix regression by not configuring PHYLINK on CPU port of bcm_sf2 switches. From Florian Fainelli. 7) Revert DMA sync removal from r8169 which was causing regressions on some MIPS Loongson platforms. From Heiner Kallweit. 8) Use after free in flow dissector, from Jakub Sitnicki. 9) Fix NULL derefs of net devices during ICMP processing across collect_md tunnels, from Hangbin Liu. 10) proto_register() memory leaks, from Zhang Lin. 11) Set NLM_F_MULTI flag in multipart netlink messages consistently, from John Fastabend. * git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (66 commits) r8152: Set memory to all 0xFFs on failed reg reads openvswitch: Fix conntrack cache with timeout ipv4: mpls: fix mpls_xmit for iptunnel nexthop: Fix nexthop_num_path for blackhole nexthops net: rds: add service level support in rds-info net: route dump netlink NLM_F_MULTI flag missing s390/qeth: reject oversized SNMP requests sock: fix potential memory leak in proto_register() MAINTAINERS: Add phylink keyword to SFF/SFP/SFP+ MODULE SUPPORT xfrm/xfrm_policy: fix dst dev null pointer dereference in collect_md mode ipv4/icmp: fix rt dst dev null pointer dereference openvswitch: Fix log message in ovs conntrack bpf: allow narrow loads of some sk_reuseport_md fields with offset > 0 bpf: fix use after free in prog symbol exposure bpf: fix precision tracking in presence of bpf2bpf calls flow_dissector: Fix potential use-after-free on BPF_PROG_DETACH Revert "r8169: remove not needed call to dma_sync_single_for_device" ipv6: propagate ipv6_add_dev's error returns out of ipv6_find_idev net/ncsi: Fix the payload copying for the request coming from Netlink qed: Add cleanup in qed_slowpath_start() ...
2019-08-27kallsyms: Don't let kallsyms_lookup_size_offset() fail on retrieving the ↵Marc Zyngier
first symbol An arm64 kernel configured with CONFIG_KPROBES=y CONFIG_KALLSYMS=y # CONFIG_KALLSYMS_ALL is not set CONFIG_KALLSYMS_BASE_RELATIVE=y reports the following kprobe failure: [ 0.032677] kprobes: failed to populate blacklist: -22 [ 0.033376] Please take care of using kprobes. It appears that kprobe fails to retrieve the symbol at address 0xffff000010081000, despite this symbol being in System.map: ffff000010081000 T __exception_text_start This symbol is part of the first group of aliases in the kallsyms_offsets array (symbol names generated using ugly hacks in scripts/kallsyms.c): kallsyms_offsets: .long 0x1000 // do_undefinstr .long 0x1000 // efi_header_end .long 0x1000 // _stext .long 0x1000 // __exception_text_start .long 0x12b0 // do_cp15instr Looking at the implementation of get_symbol_pos(), it returns the lowest index for aliasing symbols. In this case, it return 0. But kallsyms_lookup_size_offset() considers 0 as a failure, which is obviously wrong (there is definitely a valid symbol living there). In turn, the kprobe blacklisting stops abruptly, hence the original error. A CONFIG_KALLSYMS_ALL kernel wouldn't fail as there is always some random symbols at the beginning of this array, which are never looked up via kallsyms_lookup_size_offset. Fix it by considering that get_symbol_pos() is always successful (which is consistent with the other uses of this function). Fixes: ffc5089196446 ("[PATCH] Create kallsyms_lookup_size_offset()") Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Will Deacon <will@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Signed-off-by: Will Deacon <will@kernel.org>
2019-08-26bpf: handle 32-bit zext during constant blindingNaveen N. Rao
Since BPF constant blinding is performed after the verifier pass, the ALU32 instructions inserted for doubleword immediate loads don't have a corresponding zext instruction. This is causing a kernel oops on powerpc and can be reproduced by running 'test_cgroup_storage' with bpf_jit_harden=2. Fix this by emitting BPF_ZEXT during constant blinding if prog->aux->verifier_zext is set. Fixes: a4b1d3c1ddf6cb ("bpf: verifier: insert zero extension according to analysis result") Reported-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Reviewed-by: Jiong Wang <jiong.wang@netronome.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-08-25Merge branch 'timers-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull timekeeping fix from Thomas Gleixner: "A single fix for a regression caused by the generic VDSO implementation where a math overflow causes CLOCK_BOOTTIME to become a random number generator" * 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: timekeeping/vsyscall: Prevent math overflow in BOOTTIME update
2019-08-25Merge 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: "Handle the worker management in situations where a task is scheduled out on a PI lock contention correctly and schedule a new worker if possible" * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/core: Schedule new worker even if PI-blocked
2019-08-25Merge branch 'perf-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf fixes from Thomas Gleixner: "Two small fixes for kprobes and perf: - Prevent a deadlock in kprobe_optimizer() causes by reverse lock ordering - Fix a comment typo" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: kprobes: Fix potential deadlock in kprobe_optimizer() perf/x86: Fix typo in comment
2019-08-25Merge 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: "A single fix for a imbalanced kobject operation in the irq decriptor code which was unearthed by the new warnings in the kobject code" * 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: genirq: Properly pair kobject_del() with kobject_add()
2019-08-25Merge branch 'akpm' (patches from Andrew)Linus Torvalds
Mergr misc fixes from Andrew Morton: "11 fixes" Mostly VM fixes, one psi polling fix, and one parisc build fix. * emailed patches from Andrew Morton <akpm@linux-foundation.org>: mm/kasan: fix false positive invalid-free reports with CONFIG_KASAN_SW_TAGS=y mm/zsmalloc.c: fix race condition in zs_destroy_pool mm/zsmalloc.c: migration can leave pages in ZS_EMPTY indefinitely mm, page_owner: handle THP splits correctly userfaultfd_release: always remove uffd flags and clear vm_userfaultfd_ctx psi: get poll_work to run when calling poll syscall next time mm: memcontrol: flush percpu vmevents before releasing memcg mm: memcontrol: flush percpu vmstats before releasing memcg parisc: fix compilation errrors mm, page_alloc: move_freepages should not examine struct page of reserved memory mm/z3fold.c: fix race between migration and destruction
2019-08-24Merge tag 'dma-mapping-5.3-5' of git://git.infradead.org/users/hch/dma-mappingLinus Torvalds
Pull dma-mapping fixes from Christoph Hellwig: "Two fixes for regressions in this merge window: - select the Kconfig symbols for the noncoherent dma arch helpers on arm if swiotlb is selected, not just for LPAE to not break then Xen build, that uses swiotlb indirectly through swiotlb-xen - fix the page allocator fallback in dma_alloc_contiguous if the CMA allocation fails" * tag 'dma-mapping-5.3-5' of git://git.infradead.org/users/hch/dma-mapping: dma-direct: fix zone selection after an unaddressable CMA allocation arm: select the dma-noncoherent symbols for all swiotlb builds
2019-08-24psi: get poll_work to run when calling poll syscall next timeJason Xing
Only when calling the poll syscall the first time can user receive POLLPRI correctly. After that, user always fails to acquire the event signal. Reproduce case: 1. Get the monitor code in Documentation/accounting/psi.txt 2. Run it, and wait for the event triggered. 3. Kill and restart the process. The question is why we can end up with poll_scheduled = 1 but the work not running (which would reset it to 0). And the answer is because the scheduling side sees group->poll_kworker under RCU protection and then schedules it, but here we cancel the work and destroy the worker. The cancel needs to pair with resetting the poll_scheduled flag. Link: http://lkml.kernel.org/r/1566357985-97781-1-git-send-email-joseph.qi@linux.alibaba.com Signed-off-by: Jason Xing <kerneljasonxing@linux.alibaba.com> Signed-off-by: Joseph Qi <joseph.qi@linux.alibaba.com> Reviewed-by: Caspar Zhang <caspar@linux.alibaba.com> Reviewed-by: Suren Baghdasaryan <surenb@google.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-08-23Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpfDavid S. Miller
Daniel Borkmann says: ==================== pull-request: bpf 2019-08-24 The following pull-request contains BPF updates for your *net* tree. The main changes are: 1) Fix verifier precision tracking with BPF-to-BPF calls, from Alexei. 2) Fix a use-after-free in prog symbol exposure, from Daniel. 3) Several s390x JIT fixes plus BE related fixes in BPF kselftests, from Ilya. 4) Fix memory leak by unpinning XDP umem pages in error path, from Ivan. 5) Fix a potential use-after-free on flow dissector detach, from Jakub. 6) Fix bpftool to close prog fd after showing metadata, from Quentin. 7) BPF kselftest config and TEST_PROGS_EXTENDED fixes, from Anders. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2019-08-24bpf: fix use after free in prog symbol exposureDaniel Borkmann
syzkaller managed to trigger the warning in bpf_jit_free() which checks via bpf_prog_kallsyms_verify_off() for potentially unlinked JITed BPF progs in kallsyms, and subsequently trips over GPF when walking kallsyms entries: [...] 8021q: adding VLAN 0 to HW filter on device batadv0 8021q: adding VLAN 0 to HW filter on device batadv0 WARNING: CPU: 0 PID: 9869 at kernel/bpf/core.c:810 bpf_jit_free+0x1e8/0x2a0 Kernel panic - not syncing: panic_on_warn set ... CPU: 0 PID: 9869 Comm: kworker/0:7 Not tainted 5.0.0-rc8+ #1 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events bpf_prog_free_deferred Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x113/0x167 lib/dump_stack.c:113 panic+0x212/0x40b kernel/panic.c:214 __warn.cold.8+0x1b/0x38 kernel/panic.c:571 report_bug+0x1a4/0x200 lib/bug.c:186 fixup_bug arch/x86/kernel/traps.c:178 [inline] do_error_trap+0x11b/0x200 arch/x86/kernel/traps.c:271 do_invalid_op+0x36/0x40 arch/x86/kernel/traps.c:290 invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:973 RIP: 0010:bpf_jit_free+0x1e8/0x2a0 Code: 02 4c 89 e2 83 e2 07 38 d0 7f 08 84 c0 0f 85 86 00 00 00 48 ba 00 02 00 00 00 00 ad de 0f b6 43 02 49 39 d6 0f 84 5f fe ff ff <0f> 0b e9 58 fe ff ff 48 b8 00 00 00 00 00 fc ff df 4c 89 e2 48 c1 RSP: 0018:ffff888092f67cd8 EFLAGS: 00010202 RAX: 0000000000000007 RBX: ffffc90001947000 RCX: ffffffff816e9d88 RDX: dead000000000200 RSI: 0000000000000008 RDI: ffff88808769f7f0 RBP: ffff888092f67d00 R08: fffffbfff1394059 R09: fffffbfff1394058 R10: fffffbfff1394058 R11: ffffffff89ca02c7 R12: ffffc90001947002 R13: ffffc90001947020 R14: ffffffff881eca80 R15: ffff88808769f7e8 BUG: unable to handle kernel paging request at fffffbfff400d000 #PF error: [normal kernel read fault] PGD 21ffee067 P4D 21ffee067 PUD 21ffed067 PMD 9f942067 PTE 0 Oops: 0000 [#1] PREEMPT SMP KASAN CPU: 0 PID: 9869 Comm: kworker/0:7 Not tainted 5.0.0-rc8+ #1 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events bpf_prog_free_deferred RIP: 0010:bpf_get_prog_addr_region kernel/bpf/core.c:495 [inline] RIP: 0010:bpf_tree_comp kernel/bpf/core.c:558 [inline] RIP: 0010:__lt_find include/linux/rbtree_latch.h:115 [inline] RIP: 0010:latch_tree_find include/linux/rbtree_latch.h:208 [inline] RIP: 0010:bpf_prog_kallsyms_find+0x107/0x2e0 kernel/bpf/core.c:632 Code: 00 f0 ff ff 44 38 c8 7f 08 84 c0 0f 85 fa 00 00 00 41 f6 45 02 01 75 02 0f 0b 48 39 da 0f 82 92 00 00 00 48 89 d8 48 c1 e8 03 <42> 0f b6 04 30 84 c0 74 08 3c 03 0f 8e 45 01 00 00 8b 03 48 c1 e0 [...] Upon further debugging, it turns out that whenever we trigger this issue, the kallsyms removal in bpf_prog_ksym_node_del() was /skipped/ but yet bpf_jit_free() reported that the entry is /in use/. Problem is that symbol exposure via bpf_prog_kallsyms_add() but also perf_event_bpf_event() were done /after/ bpf_prog_new_fd(). Once the fd is exposed to the public, a parallel close request came in right before we attempted to do the bpf_prog_kallsyms_add(). Given at this time the prog reference count is one, we start to rip everything underneath us via bpf_prog_release() -> bpf_prog_put(). The memory is eventually released via deferred free, so we're seeing that bpf_jit_free() has a kallsym entry because we added it from bpf_prog_load() but /after/ bpf_prog_put() from the remote CPU. Therefore, move both notifications /before/ we install the fd. The issue was never seen between bpf_prog_alloc_id() and bpf_prog_new_fd() because upon bpf_prog_get_fd_by_id() we'll take another reference to the BPF prog, so we're still holding the original reference from the bpf_prog_load(). Fixes: 6ee52e2a3fe4 ("perf, bpf: Introduce PERF_RECORD_BPF_EVENT") Fixes: 74451e66d516 ("bpf: make jited programs visible in traces") Reported-by: syzbot+bd3bba6ff3fcea7a6ec6@syzkaller.appspotmail.com Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Cc: Song Liu <songliubraving@fb.com>
2019-08-24bpf: fix precision tracking in presence of bpf2bpf callsAlexei Starovoitov
While adding extra tests for precision tracking and extra infra to adjust verifier heuristics the existing test "calls: cross frame pruning - liveness propagation" started to fail. The root cause is the same as described in verifer.c comment: * Also if parent's curframe > frame where backtracking started, * the verifier need to mark registers in both frames, otherwise callees * may incorrectly prune callers. This is similar to * commit 7640ead93924 ("bpf: verifier: make sure callees don't prune with caller differences") * For now backtracking falls back into conservative marking. Turned out though that returning -ENOTSUPP from backtrack_insn() and doing mark_all_scalars_precise() in the current parentage chain is not enough. Depending on how is_state_visited() heuristic is creating parentage chain it's possible that callee will incorrectly prune caller. Fix the issue by setting precise=true earlier and more aggressively. Before this fix the precision tracking _within_ functions that don't do bpf2bpf calls would still work. Whereas now precision tracking is completely disabled when bpf2bpf calls are present anywhere in the program. No difference in cilium tests (they don't have bpf2bpf calls). No difference in test_progs though some of them have bpf2bpf calls, but precision tracking wasn't effective there. Fixes: b5dc0163d8fd ("bpf: precise scalar_value tracking") Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>