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2019-02-01Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpfDavid S. Miller7-30/+50
Alexei Starovoitov says: ==================== pull-request: bpf 2019-01-31 The following pull-request contains BPF updates for your *net* tree. The main changes are: 1) disable preemption in sender side of socket filters, from Alexei. 2) fix two potential deadlocks in syscall bpf lookup and prog_register, from Martin and Alexei. 3) fix BTF to allow typedef on func_proto, from Yonghong. 4) two bpftool fixes, from Jiri and Paolo. ==================== Signed-off-by: David S. Miller <[email protected]>
2019-01-31bpf: Fix syscall's stackmap lookup potential deadlockMartin KaFai Lau1-2/+10
The map_lookup_elem used to not acquiring spinlock in order to optimize the reader. It was true until commit 557c0c6e7df8 ("bpf: convert stackmap to pre-allocation") The syscall's map_lookup_elem(stackmap) calls bpf_stackmap_copy(). bpf_stackmap_copy() may find the elem no longer needed after the copy is done. If that is the case, pcpu_freelist_push() saves this elem for reuse later. This push requires a spinlock. If a tracing bpf_prog got run in the middle of the syscall's map_lookup_elem(stackmap) and this tracing bpf_prog is calling bpf_get_stackid(stackmap) which also requires the same pcpu_freelist's spinlock, it may end up with a dead lock situation as reported by Eric Dumazet in https://patchwork.ozlabs.org/patch/1030266/ The situation is the same as the syscall's map_update_elem() which needs to acquire the pcpu_freelist's spinlock and could race with tracing bpf_prog. Hence, this patch fixes it by protecting bpf_stackmap_copy() with this_cpu_inc(bpf_prog_active) to prevent tracing bpf_prog from running. A later syscall's map_lookup_elem commit f1a2e44a3aec ("bpf: add queue and stack maps") also acquires a spinlock and races with tracing bpf_prog similarly. Hence, this patch is forward looking and protects the majority of the map lookups. bpf_map_offload_lookup_elem() is the exception since it is for network bpf_prog only (i.e. never called by tracing bpf_prog). Fixes: 557c0c6e7df8 ("bpf: convert stackmap to pre-allocation") Reported-by: Eric Dumazet <[email protected]> Acked-by: Alexei Starovoitov <[email protected]> Signed-off-by: Martin KaFai Lau <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]> Signed-off-by: Daniel Borkmann <[email protected]>
2019-01-31bpf: fix potential deadlock in bpf_prog_registerAlexei Starovoitov1-12/+2
Lockdep found a potential deadlock between cpu_hotplug_lock, bpf_event_mutex, and cpuctx_mutex: [ 13.007000] WARNING: possible circular locking dependency detected [ 13.007587] 5.0.0-rc3-00018-g2fa53f892422-dirty #477 Not tainted [ 13.008124] ------------------------------------------------------ [ 13.008624] test_progs/246 is trying to acquire lock: [ 13.009030] 0000000094160d1d (tracepoints_mutex){+.+.}, at: tracepoint_probe_register_prio+0x2d/0x300 [ 13.009770] [ 13.009770] but task is already holding lock: [ 13.010239] 00000000d663ef86 (bpf_event_mutex){+.+.}, at: bpf_probe_register+0x1d/0x60 [ 13.010877] [ 13.010877] which lock already depends on the new lock. [ 13.010877] [ 13.011532] [ 13.011532] the existing dependency chain (in reverse order) is: [ 13.012129] [ 13.012129] -> #4 (bpf_event_mutex){+.+.}: [ 13.012582] perf_event_query_prog_array+0x9b/0x130 [ 13.013016] _perf_ioctl+0x3aa/0x830 [ 13.013354] perf_ioctl+0x2e/0x50 [ 13.013668] do_vfs_ioctl+0x8f/0x6a0 [ 13.014003] ksys_ioctl+0x70/0x80 [ 13.014320] __x64_sys_ioctl+0x16/0x20 [ 13.014668] do_syscall_64+0x4a/0x180 [ 13.015007] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 13.015469] [ 13.015469] -> #3 (&cpuctx_mutex){+.+.}: [ 13.015910] perf_event_init_cpu+0x5a/0x90 [ 13.016291] perf_event_init+0x1b2/0x1de [ 13.016654] start_kernel+0x2b8/0x42a [ 13.016995] secondary_startup_64+0xa4/0xb0 [ 13.017382] [ 13.017382] -> #2 (pmus_lock){+.+.}: [ 13.017794] perf_event_init_cpu+0x21/0x90 [ 13.018172] cpuhp_invoke_callback+0xb3/0x960 [ 13.018573] _cpu_up+0xa7/0x140 [ 13.018871] do_cpu_up+0xa4/0xc0 [ 13.019178] smp_init+0xcd/0xd2 [ 13.019483] kernel_init_freeable+0x123/0x24f [ 13.019878] kernel_init+0xa/0x110 [ 13.020201] ret_from_fork+0x24/0x30 [ 13.020541] [ 13.020541] -> #1 (cpu_hotplug_lock.rw_sem){++++}: [ 13.021051] static_key_slow_inc+0xe/0x20 [ 13.021424] tracepoint_probe_register_prio+0x28c/0x300 [ 13.021891] perf_trace_event_init+0x11f/0x250 [ 13.022297] perf_trace_init+0x6b/0xa0 [ 13.022644] perf_tp_event_init+0x25/0x40 [ 13.023011] perf_try_init_event+0x6b/0x90 [ 13.023386] perf_event_alloc+0x9a8/0xc40 [ 13.023754] __do_sys_perf_event_open+0x1dd/0xd30 [ 13.024173] do_syscall_64+0x4a/0x180 [ 13.024519] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 13.024968] [ 13.024968] -> #0 (tracepoints_mutex){+.+.}: [ 13.025434] __mutex_lock+0x86/0x970 [ 13.025764] tracepoint_probe_register_prio+0x2d/0x300 [ 13.026215] bpf_probe_register+0x40/0x60 [ 13.026584] bpf_raw_tracepoint_open.isra.34+0xa4/0x130 [ 13.027042] __do_sys_bpf+0x94f/0x1a90 [ 13.027389] do_syscall_64+0x4a/0x180 [ 13.027727] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 13.028171] [ 13.028171] other info that might help us debug this: [ 13.028171] [ 13.028807] Chain exists of: [ 13.028807] tracepoints_mutex --> &cpuctx_mutex --> bpf_event_mutex [ 13.028807] [ 13.029666] Possible unsafe locking scenario: [ 13.029666] [ 13.030140] CPU0 CPU1 [ 13.030510] ---- ---- [ 13.030875] lock(bpf_event_mutex); [ 13.031166] lock(&cpuctx_mutex); [ 13.031645] lock(bpf_event_mutex); [ 13.032135] lock(tracepoints_mutex); [ 13.032441] [ 13.032441] *** DEADLOCK *** [ 13.032441] [ 13.032911] 1 lock held by test_progs/246: [ 13.033239] #0: 00000000d663ef86 (bpf_event_mutex){+.+.}, at: bpf_probe_register+0x1d/0x60 [ 13.033909] [ 13.033909] stack backtrace: [ 13.034258] CPU: 1 PID: 246 Comm: test_progs Not tainted 5.0.0-rc3-00018-g2fa53f892422-dirty #477 [ 13.034964] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.0-2.el7 04/01/2014 [ 13.035657] Call Trace: [ 13.035859] dump_stack+0x5f/0x8b [ 13.036130] print_circular_bug.isra.37+0x1ce/0x1db [ 13.036526] __lock_acquire+0x1158/0x1350 [ 13.036852] ? lock_acquire+0x98/0x190 [ 13.037154] lock_acquire+0x98/0x190 [ 13.037447] ? tracepoint_probe_register_prio+0x2d/0x300 [ 13.037876] __mutex_lock+0x86/0x970 [ 13.038167] ? tracepoint_probe_register_prio+0x2d/0x300 [ 13.038600] ? tracepoint_probe_register_prio+0x2d/0x300 [ 13.039028] ? __mutex_lock+0x86/0x970 [ 13.039337] ? __mutex_lock+0x24a/0x970 [ 13.039649] ? bpf_probe_register+0x1d/0x60 [ 13.039992] ? __bpf_trace_sched_wake_idle_without_ipi+0x10/0x10 [ 13.040478] ? tracepoint_probe_register_prio+0x2d/0x300 [ 13.040906] tracepoint_probe_register_prio+0x2d/0x300 [ 13.041325] bpf_probe_register+0x40/0x60 [ 13.041649] bpf_raw_tracepoint_open.isra.34+0xa4/0x130 [ 13.042068] ? __might_fault+0x3e/0x90 [ 13.042374] __do_sys_bpf+0x94f/0x1a90 [ 13.042678] do_syscall_64+0x4a/0x180 [ 13.042975] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 13.043382] RIP: 0033:0x7f23b10a07f9 [ 13.045155] RSP: 002b:00007ffdef42fdd8 EFLAGS: 00000202 ORIG_RAX: 0000000000000141 [ 13.045759] RAX: ffffffffffffffda RBX: 00007ffdef42ff70 RCX: 00007f23b10a07f9 [ 13.046326] RDX: 0000000000000070 RSI: 00007ffdef42fe10 RDI: 0000000000000011 [ 13.046893] RBP: 00007ffdef42fdf0 R08: 0000000000000038 R09: 00007ffdef42fe10 [ 13.047462] R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000 [ 13.048029] R13: 0000000000000016 R14: 00007f23b1db4690 R15: 0000000000000000 Since tracepoints_mutex will be taken in tracepoint_probe_register/unregister() there is no need to take bpf_event_mutex too. bpf_event_mutex is protecting modifications to prog array used in kprobe/perf bpf progs. bpf_raw_tracepoints don't need to take this mutex. Fixes: c4f6699dfcb8 ("bpf: introduce BPF_RAW_TRACEPOINT") Acked-by: Martin KaFai Lau <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]> Signed-off-by: Daniel Borkmann <[email protected]>
2019-01-31bpf: fix lockdep false positive in percpu_freelistAlexei Starovoitov3-14/+35
Lockdep warns about false positive: [ 12.492084] 00000000e6b28347 (&head->lock){+...}, at: pcpu_freelist_push+0x2a/0x40 [ 12.492696] but this lock was taken by another, HARDIRQ-safe lock in the past: [ 12.493275] (&rq->lock){-.-.} [ 12.493276] [ 12.493276] [ 12.493276] and interrupts could create inverse lock ordering between them. [ 12.493276] [ 12.494435] [ 12.494435] other info that might help us debug this: [ 12.494979] Possible interrupt unsafe locking scenario: [ 12.494979] [ 12.495518] CPU0 CPU1 [ 12.495879] ---- ---- [ 12.496243] lock(&head->lock); [ 12.496502] local_irq_disable(); [ 12.496969] lock(&rq->lock); [ 12.497431] lock(&head->lock); [ 12.497890] <Interrupt> [ 12.498104] lock(&rq->lock); [ 12.498368] [ 12.498368] *** DEADLOCK *** [ 12.498368] [ 12.498837] 1 lock held by dd/276: [ 12.499110] #0: 00000000c58cb2ee (rcu_read_lock){....}, at: trace_call_bpf+0x5e/0x240 [ 12.499747] [ 12.499747] the shortest dependencies between 2nd lock and 1st lock: [ 12.500389] -> (&rq->lock){-.-.} { [ 12.500669] IN-HARDIRQ-W at: [ 12.500934] _raw_spin_lock+0x2f/0x40 [ 12.501373] scheduler_tick+0x4c/0xf0 [ 12.501812] update_process_times+0x40/0x50 [ 12.502294] tick_periodic+0x27/0xb0 [ 12.502723] tick_handle_periodic+0x1f/0x60 [ 12.503203] timer_interrupt+0x11/0x20 [ 12.503651] __handle_irq_event_percpu+0x43/0x2c0 [ 12.504167] handle_irq_event_percpu+0x20/0x50 [ 12.504674] handle_irq_event+0x37/0x60 [ 12.505139] handle_level_irq+0xa7/0x120 [ 12.505601] handle_irq+0xa1/0x150 [ 12.506018] do_IRQ+0x77/0x140 [ 12.506411] ret_from_intr+0x0/0x1d [ 12.506834] _raw_spin_unlock_irqrestore+0x53/0x60 [ 12.507362] __setup_irq+0x481/0x730 [ 12.507789] setup_irq+0x49/0x80 [ 12.508195] hpet_time_init+0x21/0x32 [ 12.508644] x86_late_time_init+0xb/0x16 [ 12.509106] start_kernel+0x390/0x42a [ 12.509554] secondary_startup_64+0xa4/0xb0 [ 12.510034] IN-SOFTIRQ-W at: [ 12.510305] _raw_spin_lock+0x2f/0x40 [ 12.510772] try_to_wake_up+0x1c7/0x4e0 [ 12.511220] swake_up_locked+0x20/0x40 [ 12.511657] swake_up_one+0x1a/0x30 [ 12.512070] rcu_process_callbacks+0xc5/0x650 [ 12.512553] __do_softirq+0xe6/0x47b [ 12.512978] irq_exit+0xc3/0xd0 [ 12.513372] smp_apic_timer_interrupt+0xa9/0x250 [ 12.513876] apic_timer_interrupt+0xf/0x20 [ 12.514343] default_idle+0x1c/0x170 [ 12.514765] do_idle+0x199/0x240 [ 12.515159] cpu_startup_entry+0x19/0x20 [ 12.515614] start_kernel+0x422/0x42a [ 12.516045] secondary_startup_64+0xa4/0xb0 [ 12.516521] INITIAL USE at: [ 12.516774] _raw_spin_lock_irqsave+0x38/0x50 [ 12.517258] rq_attach_root+0x16/0xd0 [ 12.517685] sched_init+0x2f2/0x3eb [ 12.518096] start_kernel+0x1fb/0x42a [ 12.518525] secondary_startup_64+0xa4/0xb0 [ 12.518986] } [ 12.519132] ... key at: [<ffffffff82b7bc28>] __key.71384+0x0/0x8 [ 12.519649] ... acquired at: [ 12.519892] pcpu_freelist_pop+0x7b/0xd0 [ 12.520221] bpf_get_stackid+0x1d2/0x4d0 [ 12.520563] ___bpf_prog_run+0x8b4/0x11a0 [ 12.520887] [ 12.521008] -> (&head->lock){+...} { [ 12.521292] HARDIRQ-ON-W at: [ 12.521539] _raw_spin_lock+0x2f/0x40 [ 12.521950] pcpu_freelist_push+0x2a/0x40 [ 12.522396] bpf_get_stackid+0x494/0x4d0 [ 12.522828] ___bpf_prog_run+0x8b4/0x11a0 [ 12.523296] INITIAL USE at: [ 12.523537] _raw_spin_lock+0x2f/0x40 [ 12.523944] pcpu_freelist_populate+0xc0/0x120 [ 12.524417] htab_map_alloc+0x405/0x500 [ 12.524835] __do_sys_bpf+0x1a3/0x1a90 [ 12.525253] do_syscall_64+0x4a/0x180 [ 12.525659] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 12.526167] } [ 12.526311] ... key at: [<ffffffff838f7668>] __key.13130+0x0/0x8 [ 12.526812] ... acquired at: [ 12.527047] __lock_acquire+0x521/0x1350 [ 12.527371] lock_acquire+0x98/0x190 [ 12.527680] _raw_spin_lock+0x2f/0x40 [ 12.527994] pcpu_freelist_push+0x2a/0x40 [ 12.528325] bpf_get_stackid+0x494/0x4d0 [ 12.528645] ___bpf_prog_run+0x8b4/0x11a0 [ 12.528970] [ 12.529092] [ 12.529092] stack backtrace: [ 12.529444] CPU: 0 PID: 276 Comm: dd Not tainted 5.0.0-rc3-00018-g2fa53f892422 #475 [ 12.530043] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.0-2.el7 04/01/2014 [ 12.530750] Call Trace: [ 12.530948] dump_stack+0x5f/0x8b [ 12.531248] check_usage_backwards+0x10c/0x120 [ 12.531598] ? ___bpf_prog_run+0x8b4/0x11a0 [ 12.531935] ? mark_lock+0x382/0x560 [ 12.532229] mark_lock+0x382/0x560 [ 12.532496] ? print_shortest_lock_dependencies+0x180/0x180 [ 12.532928] __lock_acquire+0x521/0x1350 [ 12.533271] ? find_get_entry+0x17f/0x2e0 [ 12.533586] ? find_get_entry+0x19c/0x2e0 [ 12.533902] ? lock_acquire+0x98/0x190 [ 12.534196] lock_acquire+0x98/0x190 [ 12.534482] ? pcpu_freelist_push+0x2a/0x40 [ 12.534810] _raw_spin_lock+0x2f/0x40 [ 12.535099] ? pcpu_freelist_push+0x2a/0x40 [ 12.535432] pcpu_freelist_push+0x2a/0x40 [ 12.535750] bpf_get_stackid+0x494/0x4d0 [ 12.536062] ___bpf_prog_run+0x8b4/0x11a0 It has been explained that is a false positive here: https://lkml.org/lkml/2018/7/25/756 Recap: - stackmap uses pcpu_freelist - The lock in pcpu_freelist is a percpu lock - stackmap is only used by tracing bpf_prog - A tracing bpf_prog cannot be run if another bpf_prog has already been running (ensured by the percpu bpf_prog_active counter). Eric pointed out that this lockdep splats stops other legit lockdep splats in selftests/bpf/test_progs.c. Fix this by calling local_irq_save/restore for stackmap. Another false positive had also been worked around by calling local_irq_save in commit 89ad2fa3f043 ("bpf: fix lockdep splat"). That commit added unnecessary irq_save/restore to fast path of bpf hash map. irqs are already disabled at that point, since htab is holding per bucket spin_lock with irqsave. Let's reduce overhead for htab by introducing __pcpu_freelist_push/pop function w/o irqsave and convert pcpu_freelist_push/pop to irqsave to be used elsewhere (right now only in stackmap). It stops lockdep false positive in stackmap with a bit of acceptable overhead. Fixes: 557c0c6e7df8 ("bpf: convert stackmap to pre-allocation") Reported-by: Naresh Kamboju <[email protected]> Reported-by: Eric Dumazet <[email protected]> Acked-by: Martin KaFai Lau <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]> Signed-off-by: Daniel Borkmann <[email protected]>
2019-01-31bpf: run bpf programs with preemption disabledAlexei Starovoitov1-1/+1
Disabled preemption is necessary for proper access to per-cpu maps from BPF programs. But the sender side of socket filters didn't have preemption disabled: unix_dgram_sendmsg->sk_filter->sk_filter_trim_cap->bpf_prog_run_save_cb->BPF_PROG_RUN and a combination of af_packet with tun device didn't disable either: tpacket_snd->packet_direct_xmit->packet_pick_tx_queue->ndo_select_queue-> tun_select_queue->tun_ebpf_select_queue->bpf_prog_run_clear_cb->BPF_PROG_RUN Disable preemption before executing BPF programs (both classic and extended). Reported-by: Jann Horn <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]> Acked-by: Song Liu <[email protected]> Signed-off-by: Daniel Borkmann <[email protected]>
2019-01-29bpf: btf: allow typedef func_protoYonghong Song1-1/+2
Current implementation does not allow typedef func_proto. But it is actually allowed. -bash-4.4$ cat t.c typedef int (f) (int); f *g; -bash-4.4$ clang -O2 -g -c -target bpf t.c -Xclang -target-feature -Xclang +dwarfris -bash-4.4$ pahole -JV t.o File t.o: [1] PTR (anon) type_id=2 [2] TYPEDEF f type_id=3 [3] FUNC_PROTO (anon) return=4 args=(4 (anon)) [4] INT int size=4 bit_offset=0 nr_bits=32 encoding=SIGNED -bash-4.4$ This patch related btf verifier to allow such (typedef func_proto) patterns. Fixes: 2667a2626f4d ("bpf: btf: Add BTF_KIND_FUNC and BTF_KIND_FUNC_PROTO") Acked-by: Martin KaFai Lau <[email protected]> Signed-off-by: Yonghong Song <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]>
2019-01-27Merge branch 'timers-urgent-for-linus' of ↵Linus Torvalds1-0/+1
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull timer fix from Thomas Glexiner: "A single regression fix to address the unintended breakage of posix cpu timers. This is caused by a new sanity check in the common code, which fails for posix cpu timers under certain conditions because the posix cpu timer code never updates the variable which is checked" * 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: posix-cpu-timers: Unbreak timer rearming
2019-01-27Merge branch 'locking-urgent-for-linus' of ↵Linus Torvalds4-11/+34
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull locking fixes from Thomas Gleixner: "A small series of fixes which all address possible missed wakeups: - Document and fix the wakeup ordering of wake_q - Add the missing barrier in rcuwait_wake_up(), which was documented in the comment but missing in the code - Fix the possible missed wakeups in the rwsem and futex code" * 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: locking/rwsem: Fix (possible) missed wakeup futex: Fix (possible) missed wakeup sched/wake_q: Fix wakeup ordering for wake_q sched/wake_q: Document wake_q_add() sched/wait: Fix rcuwait_wake_up() ordering
2019-01-27Merge branch 'irq-urgent-for-linus' of ↵Linus Torvalds2-1/+4
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull irq fixes from Thomas Gleixner: "A small set of fixes for the interrupt subsystem: - Fix a double increment in the irq descriptor allocator which resulted in a sanity check only being done for every second affinity mask - Add a missing device tree translation in the stm32-exti driver. Without that the interrupt association is completely wrong. - Initialize the mutex in the GIC-V3 MBI driver - Fix the alignment for aliasing devices in the GIC-V3-ITS driver so multi MSI allocations work correctly - Ensure that the initial affinity of a interrupt is not empty at startup time. - Drop bogus include in the madera irq chip driver - Fix KernelDoc regression" * 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: irqchip/gic-v3-its: Align PCI Multi-MSI allocation on their size genirq/irqdesc: Fix double increment in alloc_descs() genirq: Fix the kerneldoc comment for struct irq_affinity_desc irqchip/madera: Drop GPIO includes irqchip/gic-v3-mbi: Fix uninitialized mbi_lock irqchip/stm32-exti: Add domain translate function genirq: Make sure the initial affinity is not empty
2019-01-21locking/rwsem: Fix (possible) missed wakeupXie Yongji1-2/+9
Because wake_q_add() can imply an immediate wakeup (cmpxchg failure case), we must not rely on the wakeup being delayed. However, commit: e38513905eea ("locking/rwsem: Rework zeroing reader waiter->task") relies on exactly that behaviour in that the wakeup must not happen until after we clear waiter->task. [ peterz: Added changelog. ] Signed-off-by: Xie Yongji <[email protected]> Signed-off-by: Zhang Yu <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Fixes: e38513905eea ("locking/rwsem: Rework zeroing reader waiter->task") Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2019-01-21futex: Fix (possible) missed wakeupPeter Zijlstra1-5/+8
We must not rely on wake_q_add() to delay the wakeup; in particular commit: 1d0dcb3ad9d3 ("futex: Implement lockless wakeups") moved wake_q_add() before smp_store_release(&q->lock_ptr, NULL), which could result in futex_wait() waking before observing ->lock_ptr == NULL and going back to sleep again. Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Fixes: 1d0dcb3ad9d3 ("futex: Implement lockless wakeups") Signed-off-by: Ingo Molnar <[email protected]>
2019-01-21sched/wake_q: Fix wakeup ordering for wake_qPeter Zijlstra1-3/+4
Notable cmpxchg() does not provide ordering when it fails, however wake_q_add() requires ordering in this specific case too. Without this it would be possible for the concurrent wakeup to not observe our prior state. Andrea Parri provided: C wake_up_q-wake_q_add { int next = 0; int y = 0; } P0(int *next, int *y) { int r0; /* in wake_up_q() */ WRITE_ONCE(*next, 1); /* node->next = NULL */ smp_mb(); /* implied by wake_up_process() */ r0 = READ_ONCE(*y); } P1(int *next, int *y) { int r1; /* in wake_q_add() */ WRITE_ONCE(*y, 1); /* wake_cond = true */ smp_mb__before_atomic(); r1 = cmpxchg_relaxed(next, 1, 2); } exists (0:r0=0 /\ 1:r1=0) This "exists" clause cannot be satisfied according to the LKMM: Test wake_up_q-wake_q_add Allowed States 3 0:r0=0; 1:r1=1; 0:r0=1; 1:r1=0; 0:r0=1; 1:r1=1; No Witnesses Positive: 0 Negative: 3 Condition exists (0:r0=0 /\ 1:r1=0) Observation wake_up_q-wake_q_add Never 0 3 Reported-by: Yongji Xie <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: Davidlohr Bueso <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Waiman Long <[email protected]> Cc: Will Deacon <[email protected]> Signed-off-by: Ingo Molnar <[email protected]>
2019-01-21sched/wake_q: Document wake_q_add()Peter Zijlstra1-0/+12
The only guarantee provided by wake_q_add() is that a wakeup will happen after it, it does _NOT_ guarantee the wakeup will be delayed until the matching wake_up_q(). If wake_q_add() fails the cmpxchg() a concurrent wakeup is pending and that can happen at any time after the cmpxchg(). This means we should not rely on the wakeup happening at wake_q_up(), but should be ready for wake_q_add() to issue the wakeup. The delay; if provided (most likely); should only result in more efficient behaviour. Reported-by: Yongji Xie <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: Davidlohr Bueso <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Waiman Long <[email protected]> Cc: Will Deacon <[email protected]> Signed-off-by: Ingo Molnar <[email protected]>
2019-01-21sched/wait: Fix rcuwait_wake_up() orderingPrateek Sood1-1/+1
For some peculiar reason rcuwait_wake_up() has the right barrier in the comment, but not in the code. This mistake has been observed to cause a deadlock in the following situation: P1 P2 percpu_up_read() percpu_down_write() rcu_sync_is_idle() // false rcu_sync_enter() ... __percpu_up_read() [S] ,- __this_cpu_dec(*sem->read_count) | smp_rmb(); [L] | task = rcu_dereference(w->task) // NULL | | [S] w->task = current | smp_mb(); | [L] readers_active_check() // fail `-> <store happens here> Where the smp_rmb() (obviously) fails to constrain the store. [ peterz: Added changelog. ] Signed-off-by: Prateek Sood <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Reviewed-by: Andrea Parri <[email protected]> Acked-by: Davidlohr Bueso <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Fixes: 8f95c90ceb54 ("sched/wait, RCU: Introduce rcuwait machinery") Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2019-01-21Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netLinus Torvalds4-5/+24
Pull networking fixes from David Miller: 1) Fix endless loop in nf_tables, from Phil Sutter. 2) Fix cross namespace ip6_gre tunnel hash list corruption, from Olivier Matz. 3) Don't be too strict in phy_start_aneg() otherwise we might not allow restarting auto negotiation. From Heiner Kallweit. 4) Fix various KMSAN uninitialized value cases in tipc, from Ying Xue. 5) Memory leak in act_tunnel_key, from Davide Caratti. 6) Handle chip errata of mv88e6390 PHY, from Andrew Lunn. 7) Remove linear SKB assumption in fou/fou6, from Eric Dumazet. 8) Missing udplite rehash callbacks, from Alexey Kodanev. 9) Log dirty pages properly in vhost, from Jason Wang. 10) Use consume_skb() in neigh_probe() as this is a normal free not a drop, from Yang Wei. Likewise in macvlan_process_broadcast(). 11) Missing device_del() in mdiobus_register() error paths, from Thomas Petazzoni. 12) Fix checksum handling of short packets in mlx5, from Cong Wang. * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (96 commits) bpf: in __bpf_redirect_no_mac pull mac only if present virtio_net: bulk free tx skbs net: phy: phy driver features are mandatory isdn: avm: Fix string plus integer warning from Clang net/mlx5e: Fix cb_ident duplicate in indirect block register net/mlx5e: Fix wrong (zero) TX drop counter indication for representor net/mlx5e: Fix wrong error code return on FEC query failure net/mlx5e: Force CHECKSUM_UNNECESSARY for short ethernet frames tools: bpftool: Cleanup license mess bpf: fix inner map masking to prevent oob under speculation bpf: pull in pkt_sched.h header for tooling to fix bpftool build selftests: forwarding: Add a test case for externally learned FDB entries selftests: mlxsw: Test FDB offload indication mlxsw: spectrum_switchdev: Do not treat static FDB entries as sticky net: bridge: Mark FDB entries that were added by user as such mlxsw: spectrum_fid: Update dummy FID index mlxsw: pci: Return error on PCI reset timeout mlxsw: pci: Increase PCI SW reset timeout mlxsw: pci: Ring CQ's doorbell before RDQ's MAINTAINERS: update email addresses of liquidio driver maintainers ...
2019-01-18bpf: fix inner map masking to prevent oob under speculationDaniel Borkmann1-2/+15
During review I noticed that inner meta map setup for map in map is buggy in that it does not propagate all needed data from the reference map which the verifier is later accessing. In particular one such case is index masking to prevent out of bounds access under speculative execution due to missing the map's unpriv_array/index_mask field propagation. Fix this such that the verifier is generating the correct code for inlined lookups in case of unpriviledged use. Before patch (test_verifier's 'map in map access' dump): # bpftool prog dump xla id 3 0: (62) *(u32 *)(r10 -4) = 0 1: (bf) r2 = r10 2: (07) r2 += -4 3: (18) r1 = map[id:4] 5: (07) r1 += 272 | 6: (61) r0 = *(u32 *)(r2 +0) | 7: (35) if r0 >= 0x1 goto pc+6 | Inlined map in map lookup 8: (54) (u32) r0 &= (u32) 0 | with index masking for 9: (67) r0 <<= 3 | map->unpriv_array. 10: (0f) r0 += r1 | 11: (79) r0 = *(u64 *)(r0 +0) | 12: (15) if r0 == 0x0 goto pc+1 | 13: (05) goto pc+1 | 14: (b7) r0 = 0 | 15: (15) if r0 == 0x0 goto pc+11 16: (62) *(u32 *)(r10 -4) = 0 17: (bf) r2 = r10 18: (07) r2 += -4 19: (bf) r1 = r0 20: (07) r1 += 272 | 21: (61) r0 = *(u32 *)(r2 +0) | Index masking missing (!) 22: (35) if r0 >= 0x1 goto pc+3 | for inner map despite 23: (67) r0 <<= 3 | map->unpriv_array set. 24: (0f) r0 += r1 | 25: (05) goto pc+1 | 26: (b7) r0 = 0 | 27: (b7) r0 = 0 28: (95) exit After patch: # bpftool prog dump xla id 1 0: (62) *(u32 *)(r10 -4) = 0 1: (bf) r2 = r10 2: (07) r2 += -4 3: (18) r1 = map[id:2] 5: (07) r1 += 272 | 6: (61) r0 = *(u32 *)(r2 +0) | 7: (35) if r0 >= 0x1 goto pc+6 | Same inlined map in map lookup 8: (54) (u32) r0 &= (u32) 0 | with index masking due to 9: (67) r0 <<= 3 | map->unpriv_array. 10: (0f) r0 += r1 | 11: (79) r0 = *(u64 *)(r0 +0) | 12: (15) if r0 == 0x0 goto pc+1 | 13: (05) goto pc+1 | 14: (b7) r0 = 0 | 15: (15) if r0 == 0x0 goto pc+12 16: (62) *(u32 *)(r10 -4) = 0 17: (bf) r2 = r10 18: (07) r2 += -4 19: (bf) r1 = r0 20: (07) r1 += 272 | 21: (61) r0 = *(u32 *)(r2 +0) | 22: (35) if r0 >= 0x1 goto pc+4 | Now fixed inlined inner map 23: (54) (u32) r0 &= (u32) 0 | lookup with proper index masking 24: (67) r0 <<= 3 | for map->unpriv_array. 25: (0f) r0 += r1 | 26: (05) goto pc+1 | 27: (b7) r0 = 0 | 28: (b7) r0 = 0 29: (95) exit Fixes: b2157399cc98 ("bpf: prevent out-of-bounds speculation") Signed-off-by: Daniel Borkmann <[email protected]> Acked-by: Martin KaFai Lau <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]>
2019-01-18genirq/irqdesc: Fix double increment in alloc_descs()Huacai Chen1-1/+1
The recent rework of alloc_descs() introduced a double increment of the loop counter. As a consequence only every second affinity mask is validated. Remove it. [ tglx: Massaged changelog ] Fixes: c410abbbacb9 ("genirq/affinity: Add is_managed to struct irq_affinity_desc") Signed-off-by: Huacai Chen <[email protected]> Signed-off-by: Thomas Gleixner <[email protected]> Cc: Fuxin Zhang <[email protected]> Cc: Zhangjin Wu <[email protected]> Cc: Huacai Chen <[email protected]> Cc: Dou Liyang <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2019-01-18Merge branch 'stable/for-linus-5.0' of ↵Linus Torvalds1-0/+2
git://git.kernel.org/pub/scm/linux/kernel/git/konrad/swiotlb Pull swiotlb fix from Konrad Rzeszutek Wilk: "A tiny fix for v5.0-rc2: This fixes an issue with GPU cards not working anymore with the DMA mapping work Christopher did - as the SWIOTLB is initialized first and then free'd (as IOMMU is available) but we forgot to clear our start and end entries which are used and BOOM" * 'stable/for-linus-5.0' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/swiotlb: swiotlb: clear io_tlb_start and io_tlb_end in swiotlb_exit
2019-01-17bpf: Annotate implicit fall through in cgroup_dev_func_protoMathieu Malaterre1-0/+1
There is a plan to build the kernel with -Wimplicit-fallthrough and this place in the code produced a warnings (W=1). This commit removes the following warning: kernel/bpf/cgroup.c:719:6: warning: this statement may fall through [-Wimplicit-fallthrough=] Signed-off-by: Mathieu Malaterre <[email protected]> Signed-off-by: Daniel Borkmann <[email protected]>
2019-01-17bpf: Make function btf_name_offset_valid staticMathieu Malaterre1-1/+1
Initially in commit 69b693f0aefa ("bpf: btf: Introduce BPF Type Format (BTF)") the function 'btf_name_offset_valid' was introduced as static function it was later on changed to a non-static one, and then finally in commit 23127b33ec80 ("bpf: Create a new btf_name_by_offset() for non type name use case") the function prototype was removed. Revert back to original implementation and make the function static. Remove warning triggered with W=1: kernel/bpf/btf.c:470:6: warning: no previous prototype for 'btf_name_offset_valid' [-Wmissing-prototypes] Fixes: 23127b33ec80 ("bpf: Create a new btf_name_by_offset() for non type name use case") Signed-off-by: Mathieu Malaterre <[email protected]> Acked-by: Martin KaFai Lau <[email protected]> Signed-off-by: Daniel Borkmann <[email protected]>
2019-01-17bpf: zero out build_id for BPF_STACK_BUILD_ID_IPStanislav Fomichev1-0/+2
When returning BPF_STACK_BUILD_ID_IP from stack_map_get_build_id_offset, make sure that build_id field is empty. Since we are using percpu free list, there is a possibility that we might reuse some previous bpf_stack_build_id with non-zero build_id. Fixes: 615755a77b24 ("bpf: extend stackmap to save binary_build_id+offset instead of address") Acked-by: Song Liu <[email protected]> Signed-off-by: Stanislav Fomichev <[email protected]> Signed-off-by: Daniel Borkmann <[email protected]>
2019-01-17bpf: don't assume build-id length is always 20 bytesStanislav Fomichev1-2/+5
Build-id length is not fixed to 20, it can be (`man ld` /--build-id): * 128-bit (uuid) * 160-bit (sha1) * any length specified in ld --build-id=0xhexstring To fix the issue of missing BPF_STACK_BUILD_ID_VALID for shorter build-ids, assume that build-id is somewhere in the range of 1 .. 20. Set the remaining bytes to zero. v2: * don't introduce new "len = min(BPF_BUILD_ID_SIZE, nhdr->n_descsz)", we already know that nhdr->n_descsz <= BPF_BUILD_ID_SIZE if we enter this 'if' condition Fixes: 615755a77b24 ("bpf: extend stackmap to save binary_build_id+offset instead of address") Acked-by: Song Liu <[email protected]> Signed-off-by: Stanislav Fomichev <[email protected]> Signed-off-by: Daniel Borkmann <[email protected]>
2019-01-16swiotlb: clear io_tlb_start and io_tlb_end in swiotlb_exitChristoph Hellwig1-0/+2
Otherwise is_swiotlb_buffer will return false positives when we first initialize a swiotlb buffer, but then free it because we have an IOMMU available. Fixes: 55897af63091 ("dma-direct: merge swiotlb_dma_ops into the dma_direct code") Reported-by: Sibren Vasse <[email protected]> Signed-off-by: Christoph Hellwig <[email protected]> Tested-by: Sibren Vasse <[email protected]> Signed-off-by: Konrad Rzeszutek Wilk <[email protected]>
2019-01-15seccomp: fix UAF in user-trap codeTycho Andersen1-0/+4
On the failure path, we do an fput() of the listener fd if the filter fails to install (e.g. because of a TSYNC race that's lost, or if the thread is killed, etc.). fput() doesn't actually release the fd, it just ads it to a work queue. Then the thread proceeds to free the filter, even though the listener struct file has a reference to it. To fix this, on the failure path let's set the private data to null, so we know in ->release() to ignore the filter. Reported-by: [email protected] Fixes: 6a21cc50f0c7 ("seccomp: add a return code to trap to userspace") Signed-off-by: Tycho Andersen <[email protected]> Acked-by: Kees Cook <[email protected]> Signed-off-by: James Morris <[email protected]>
2019-01-16Merge tag 'trace-v5.0-rc1' of ↵Linus Torvalds1-3/+9
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing fix from Steven Rostedt: "Andrea Righi fixed a NULL pointer dereference in trace_kprobe_create() It is possible to trigger a NULL pointer dereference by writing an incorrectly formatted string to the krpobe_events file" * tag 'trace-v5.0-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: tracing/kprobes: Fix NULL pointer dereference in trace_kprobe_create()
2019-01-16Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netLinus Torvalds5-22/+88
Pull networking fixes from David Miller: 1) Fix regression in multi-SKB responses to RTM_GETADDR, from Arthur Gautier. 2) Fix ipv6 frag parsing in openvswitch, from Yi-Hung Wei. 3) Unbounded recursion in ipv4 and ipv6 GUE tunnels, from Stefano Brivio. 4) Use after free in hns driver, from Yonglong Liu. 5) icmp6_send() needs to handle the case of NULL skb, from Eric Dumazet. 6) Missing rcu read lock in __inet6_bind() when operating on mapped addresses, from David Ahern. 7) Memory leak in tipc-nl_compat_publ_dump(), from Gustavo A. R. Silva. 8) Fix PHY vs r8169 module loading ordering issues, from Heiner Kallweit. 9) Fix bridge vlan memory leak, from Ido Schimmel. 10) Dev refcount leak in AF_PACKET, from Jason Gunthorpe. 11) Infoleak in ipv6_local_error(), flow label isn't completely initialized. From Eric Dumazet. 12) Handle mv88e6390 errata, from Andrew Lunn. 13) Making vhost/vsock CID hashing consistent, from Zha Bin. 14) Fix lack of UMH cleanup when it unexpectedly exits, from Taehee Yoo. 15) Bridge forwarding must clear skb->tstamp, from Paolo Abeni. * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (87 commits) bnxt_en: Fix context memory allocation. bnxt_en: Fix ring checking logic on 57500 chips. mISDN: hfcsusb: Use struct_size() in kzalloc() net: clear skb->tstamp in bridge forwarding path net: bpfilter: disallow to remove bpfilter module while being used net: bpfilter: restart bpfilter_umh when error occurred net: bpfilter: use cleanup callback to release umh_info umh: add exit routine for UMH process isdn: i4l: isdn_tty: Fix some concurrency double-free bugs vhost/vsock: fix vhost vsock cid hashing inconsistent net: stmmac: Prevent RX starvation in stmmac_napi_poll() net: stmmac: Fix the logic of checking if RX Watchdog must be enabled net: stmmac: Check if CBS is supported before configuring net: stmmac: dwxgmac2: Only clear interrupts that are active net: stmmac: Fix PCI module removal leak tools/bpf: fix bpftool map dump with bitfields tools/bpf: test btf bitfield with >=256 struct member offset bpf: fix bpffs bitfield pretty print net: ethernet: mediatek: fix warning in phy_start_aneg tcp: change txhash on SYN-data timeout ...
2019-01-15tracing/kprobes: Fix NULL pointer dereference in trace_kprobe_create()Andrea Righi1-3/+9
It is possible to trigger a NULL pointer dereference by writing an incorrectly formatted string to krpobe_events (trying to create a kretprobe omitting the symbol). Example: echo "r:event_1 " >> /sys/kernel/debug/tracing/kprobe_events That triggers this: BUG: unable to handle kernel NULL pointer dereference at 0000000000000000 #PF error: [normal kernel read fault] PGD 0 P4D 0 Oops: 0000 [#1] SMP PTI CPU: 6 PID: 1757 Comm: bash Not tainted 5.0.0-rc1+ #125 Hardware name: Dell Inc. XPS 13 9370/0F6P3V, BIOS 1.5.1 08/09/2018 RIP: 0010:kstrtoull+0x2/0x20 Code: 28 00 00 00 75 17 48 83 c4 18 5b 41 5c 5d c3 b8 ea ff ff ff eb e1 b8 de ff ff ff eb da e8 d6 36 bb ff 66 0f 1f 44 00 00 31 c0 <80> 3f 2b 55 48 89 e5 0f 94 c0 48 01 c7 e8 5c ff ff ff 5d c3 66 2e RSP: 0018:ffffb5d482e57cb8 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffffffff82b12720 RDX: ffffb5d482e57cf8 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffb5d482e57d70 R08: ffffa0c05e5a7080 R09: ffffa0c05e003980 R10: 0000000000000000 R11: 0000000040000000 R12: ffffa0c04fe87b08 R13: 0000000000000001 R14: 000000000000000b R15: ffffa0c058d749e1 FS: 00007f137c7f7740(0000) GS:ffffa0c05e580000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 0000000497d46004 CR4: 00000000003606e0 Call Trace: ? trace_kprobe_create+0xb6/0x840 ? _cond_resched+0x19/0x40 ? _cond_resched+0x19/0x40 ? __kmalloc+0x62/0x210 ? argv_split+0x8f/0x140 ? trace_kprobe_create+0x840/0x840 ? trace_kprobe_create+0x840/0x840 create_or_delete_trace_kprobe+0x11/0x30 trace_run_command+0x50/0x90 trace_parse_run_command+0xc1/0x160 probes_write+0x10/0x20 __vfs_write+0x3a/0x1b0 ? apparmor_file_permission+0x1a/0x20 ? security_file_permission+0x31/0xf0 ? _cond_resched+0x19/0x40 vfs_write+0xb1/0x1a0 ksys_write+0x55/0xc0 __x64_sys_write+0x1a/0x20 do_syscall_64+0x5a/0x120 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Fix by doing the proper argument checks in trace_kprobe_create(). Cc: Ingo Molnar <[email protected]> Link: https://lore.kernel.org/lkml/[email protected] Link: http://lkml.kernel.org/r/20190111060113.GA22841@xps-13 Fixes: 6212dd29683e ("tracing/kprobes: Use dyn_event framework for kprobe events") Acked-by: Masami Hiramatsu <[email protected]> Signed-off-by: Andrea Righi <[email protected]> Signed-off-by: Masami Hiramatsu <[email protected]> Signed-off-by: Steven Rostedt (VMware) <[email protected]>
2019-01-15posix-cpu-timers: Unbreak timer rearmingThomas Gleixner1-0/+1
The recent commit which prevented a division by 0 issue in the alarm timer code broke posix CPU timers as an unwanted side effect. The reason is that the common rearm code checks for timer->it_interval being 0 now. What went unnoticed is that the posix cpu timer setup does not initialize timer->it_interval as it stores the interval in CPU timer specific storage. The reason for the separate storage is historical as the posix CPU timers always had a 64bit nanoseconds representation internally while timer->it_interval is type ktime_t which used to be a modified timespec representation on 32bit machines. Instead of reverting the offending commit and fixing the alarmtimer issue in the alarmtimer code, store the interval in timer->it_interval at CPU timer setup time so the common code check works. This also repairs the existing inconistency of the posix CPU timer code which kept a single shot timer armed despite of the interval being 0. The separate storage can be removed in mainline, but that needs to be a separate commit as the current one has to be backported to stable kernels. Fixes: 0e334db6bb4b ("posix-timers: Fix division by zero bug") Reported-by: H.J. Lu <[email protected]> Signed-off-by: Thomas Gleixner <[email protected]> Cc: John Stultz <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: [email protected] Link: https://lkml.kernel.org/r/[email protected]
2019-01-15genirq: Make sure the initial affinity is not emptySrinivas Ramana1-0/+3
If all CPUs in the irq_default_affinity mask are offline when an interrupt is initialized then irq_setup_affinity() can set an empty affinity mask for a newly allocated interrupt. Fix this by falling back to cpu_online_mask in case the resulting affinity mask is zero. Signed-off-by: Srinivas Ramana <[email protected]> Signed-off-by: Thomas Gleixner <[email protected]> Cc: [email protected] Link: https://lkml.kernel.org/r/[email protected]
2019-01-14kernel/sys.c: Clarify that UNAME26 does not generate unique versions anymoreJonathan Neuschäfer1-1/+2
UNAME26 is a mechanism to report Linux's version as 2.6.x, for compatibility with old/broken software. Due to the way it is implemented, it would have to be updated after 5.0, to keep the resulting versions unique. Linus Torvalds argued: "Do we actually need this? I'd rather let it bitrot, and just let it return random versions. It will just start again at 2.4.60, won't it? Anybody who uses UNAME26 for a 5.x kernel might as well think it's still 4.x. The user space is so old that it can't possibly care about differences between 4.x and 5.x, can it? The only thing that matters is that it shows "2.4.<largeenough>", which it will do regardless" Signed-off-by: Jonathan Neuschäfer <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2019-01-11umh: add exit routine for UMH processTaehee Yoo2-2/+32
A UMH process which is created by the fork_usermode_blob() such as bpfilter needs to release members of the umh_info when process is terminated. But the do_exit() does not release members of the umh_info. hence module which uses UMH needs own code to detect whether UMH process is terminated or not. But this implementation needs extra code for checking the status of UMH process. it eventually makes the code more complex. The new PF_UMH flag is added and it is used to identify UMH processes. The exit_umh() does not release members of the umh_info. Hence umh_info->cleanup callback should release both members of the umh_info and the private data. Suggested-by: David S. Miller <[email protected]> Signed-off-by: Taehee Yoo <[email protected]> Signed-off-by: David S. Miller <[email protected]>
2019-01-11bpf: fix bpffs bitfield pretty printYonghong Song1-6/+6
Commit 9d5f9f701b18 ("bpf: btf: fix struct/union/fwd types with kind_flag") introduced kind_flag and used bitfield_size in the btf_member to directly pretty print member values. The commit contained a bug where the incorrect parameters could be passed to function btf_bitfield_seq_show(). The bits_offset parameter in the function expects a value less than 8. Instead, the member offset in the structure is passed. The below is btf_bitfield_seq_show() func signature: void btf_bitfield_seq_show(void *data, u8 bits_offset, u8 nr_bits, struct seq_file *m) both bits_offset and nr_bits are u8 type. If the bitfield member offset is greater than 256, incorrect value will be printed. This patch fixed the issue by calculating correct proper data offset and bits_offset similar to non kind_flag case. Fixes: 9d5f9f701b18 ("bpf: btf: fix struct/union/fwd types with kind_flag") Acked-by: Martin KaFai Lau <[email protected]> Signed-off-by: Yonghong Song <[email protected]> Signed-off-by: Daniel Borkmann <[email protected]>
2019-01-10bpf: fix panic in stack_map_get_build_id() on i386 and arm32Song Liu1-1/+2
As Naresh reported, test_stacktrace_build_id() causes panic on i386 and arm32 systems. This is caused by page_address() returns NULL in certain cases. This patch fixes this error by using kmap_atomic/kunmap_atomic instead of page_address. Fixes: 615755a77b24 (" bpf: extend stackmap to save binary_build_id+offset instead of address") Reported-by: Naresh Kamboju <[email protected]> Signed-off-by: Song Liu <[email protected]> Signed-off-by: Daniel Borkmann <[email protected]>
2019-01-08Merge branch 'akpm' (patches from Andrew)Linus Torvalds1-0/+1
Merge misc fixes from Andrew Morton: "14 fixes" * emailed patches from Andrew Morton <[email protected]>: mm, page_alloc: do not wake kswapd with zone lock held hugetlbfs: revert "use i_mmap_rwsem for more pmd sharing synchronization" hugetlbfs: revert "Use i_mmap_rwsem to fix page fault/truncate race" mm: page_mapped: don't assume compound page is huge or THP mm/memory.c: initialise mmu_notifier_range correctly tools/vm/page_owner: use page_owner_sort in the use example kasan: fix krealloc handling for tag-based mode kasan: make tag based mode work with CONFIG_HARDENED_USERCOPY kasan, arm64: use ARCH_SLAB_MINALIGN instead of manual aligning mm, memcg: fix reclaim deadlock with writeback mm/usercopy.c: no check page span for stack objects slab: alien caches must not be initialized if the allocation of the alien cache failed fork, memcg: fix cached_stacks case zram: idle writeback fixes and cleanup
2019-01-08fork, memcg: fix cached_stacks caseShakeel Butt1-0/+1
Commit 5eed6f1dff87 ("fork,memcg: fix crash in free_thread_stack on memcg charge fail") fixes a crash caused due to failed memcg charge of the kernel stack. However the fix misses the cached_stacks case which this patch fixes. So, the same crash can happen if the memcg charge of a cached stack is failed. Link: http://lkml.kernel.org/r/[email protected] Fixes: 5eed6f1dff87 ("fork,memcg: fix crash in free_thread_stack on memcg charge fail") Signed-off-by: Shakeel Butt <[email protected]> Acked-by: Michal Hocko <[email protected]> Acked-by: Rik van Riel <[email protected]> Cc: Rik van Riel <[email protected]> Cc: Roman Gushchin <[email protected]> Cc: Johannes Weiner <[email protected]> Cc: Tejun Heo <[email protected]> Cc: <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2019-01-08fork: record start_time lateDavid Herrmann1-2/+11
This changes the fork(2) syscall to record the process start_time after initializing the basic task structure but still before making the new process visible to user-space. Technically, we could record the start_time anytime during fork(2). But this might lead to scenarios where a start_time is recorded long before a process becomes visible to user-space. For instance, with userfaultfd(2) and TLS, user-space can delay the execution of fork(2) for an indefinite amount of time (and will, if this causes network access, or similar). By recording the start_time late, it much closer reflects the point in time where the process becomes live and can be observed by other processes. Lastly, this makes it much harder for user-space to predict and control the start_time they get assigned. Previously, user-space could fork a process and stall it in copy_thread_tls() before its pid is allocated, but after its start_time is recorded. This can be misused to later-on cycle through PIDs and resume the stalled fork(2) yielding a process that has the same pid and start_time as a process that existed before. This can be used to circumvent security systems that identify processes by their pid+start_time combination. Even though user-space was always aware that start_time recording is flaky (but several projects are known to still rely on start_time-based identification), changing the start_time to be recorded late will help mitigate existing attacks and make it much harder for user-space to control the start_time a process gets assigned. Reported-by: Jann Horn <[email protected]> Signed-off-by: Tom Gundersen <[email protected]> Signed-off-by: David Herrmann <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2019-01-06Merge tag 'kbuild-v4.21-3' of ↵Linus Torvalds7-18/+18
git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull more Kbuild updates from Masahiro Yamada: - improve boolinit.cocci and use_after_iter.cocci semantic patches - fix alignment for kallsyms - move 'asm goto' compiler test to Kconfig and clean up jump_label CONFIG option - generate asm-generic wrappers automatically if arch does not implement mandatory UAPI headers - remove redundant generic-y defines - misc cleanups * tag 'kbuild-v4.21-3' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: kconfig: rename generated .*conf-cfg to *conf-cfg kbuild: remove unnecessary stubs for archheader and archscripts kbuild: use assignment instead of define ... endef for filechk_* rules arch: remove redundant UAPI generic-y defines kbuild: generate asm-generic wrappers if mandatory headers are missing arch: remove stale comments "UAPI Header export list" riscv: remove redundant kernel-space generic-y kbuild: change filechk to surround the given command with { } kbuild: remove redundant target cleaning on failure kbuild: clean up rule_dtc_dt_yaml kbuild: remove UIMAGE_IN and UIMAGE_OUT jump_label: move 'asm goto' support test to Kconfig kallsyms: lower alignment on ARM scripts: coccinelle: boolinit: drop warnings on named constants scripts: coccinelle: check for redeclaration kconfig: remove unused "file" field of yylval union nds32: remove redundant kernel-space generic-y nios2: remove unneeded HAS_DMA define
2019-01-06Merge tag 'dma-mapping-4.21-1' of git://git.infradead.org/users/hch/dma-mappingLinus Torvalds4-117/+11
Pull dma-mapping fixes from Christoph Hellwig: "Fix various regressions introduced in this cycles: - fix dma-debug tracking for the map_page / map_single consolidatation - properly stub out DMA mapping symbols for !HAS_DMA builds to avoid link failures - fix AMD Gart direct mappings - setup the dma address for no kernel mappings using the remap allocator" * tag 'dma-mapping-4.21-1' of git://git.infradead.org/users/hch/dma-mapping: dma-direct: fix DMA_ATTR_NO_KERNEL_MAPPING for remapped allocations x86/amd_gart: fix unmapping of non-GART mappings dma-mapping: remove a few unused exports dma-mapping: properly stub out the DMA API for !CONFIG_HAS_DMA dma-mapping: remove dmam_{declare,release}_coherent_memory dma-mapping: implement dmam_alloc_coherent using dmam_alloc_attrs dma-mapping: implement dma_map_single_attrs using dma_map_page_attrs
2019-01-05bpf: fix sanitation of alu op with pointer / scalar type from different pathsDaniel Borkmann1-13/+48
While 979d63d50c0c ("bpf: prevent out of bounds speculation on pointer arithmetic") took care of rejecting alu op on pointer when e.g. pointer came from two different map values with different map properties such as value size, Jann reported that a case was not covered yet when a given alu op is used in both "ptr_reg += reg" and "numeric_reg += reg" from different branches where we would incorrectly try to sanitize based on the pointer's limit. Catch this corner case and reject the program instead. Fixes: 979d63d50c0c ("bpf: prevent out of bounds speculation on pointer arithmetic") Reported-by: Jann Horn <[email protected]> Signed-off-by: Daniel Borkmann <[email protected]> Acked-by: Alexei Starovoitov <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]>
2019-01-06kbuild: change filechk to surround the given command with { }Masahiro Yamada1-1/+5
filechk_* rules often consist of multiple 'echo' lines. They must be surrounded with { } or ( ) to work correctly. Otherwise, only the string from the last 'echo' would be written into the target. Let's take care of that in the 'filechk' in scripts/Kbuild.include to clean up filechk_* rules. Signed-off-by: Masahiro Yamada <[email protected]>
2019-01-06jump_label: move 'asm goto' support test to KconfigMasahiro Yamada6-17/+13
Currently, CONFIG_JUMP_LABEL just means "I _want_ to use jump label". The jump label is controlled by HAVE_JUMP_LABEL, which is defined like this: #if defined(CC_HAVE_ASM_GOTO) && defined(CONFIG_JUMP_LABEL) # define HAVE_JUMP_LABEL #endif We can improve this by testing 'asm goto' support in Kconfig, then make JUMP_LABEL depend on CC_HAS_ASM_GOTO. Ugly #ifdef HAVE_JUMP_LABEL will go away, and CONFIG_JUMP_LABEL will match to the real kernel capability. Signed-off-by: Masahiro Yamada <[email protected]> Acked-by: Michael Ellerman <[email protected]> (powerpc) Tested-by: Sedat Dilek <[email protected]>
2019-01-05Merge branch 'akpm' (patches from Andrew)Linus Torvalds10-21/+52
Merge more updates from Andrew Morton: - procfs updates - various misc bits - lib/ updates - epoll updates - autofs - fatfs - a few more MM bits * emailed patches from Andrew Morton <[email protected]>: (58 commits) mm/page_io.c: fix polled swap page in checkpatch: add Co-developed-by to signature tags docs: fix Co-Developed-by docs drivers/base/platform.c: kmemleak ignore a known leak fs: don't open code lru_to_page() fs/: remove caller signal_pending branch predictions mm/: remove caller signal_pending branch predictions arch/arc/mm/fault.c: remove caller signal_pending_branch predictions kernel/sched/: remove caller signal_pending branch predictions kernel/locking/mutex.c: remove caller signal_pending branch predictions mm: select HAVE_MOVE_PMD on x86 for faster mremap mm: speed up mremap by 20x on large regions mm: treewide: remove unused address argument from pte_alloc functions initramfs: cleanup incomplete rootfs scripts/gdb: fix lx-version string output kernel/kcov.c: mark write_comp_data() as notrace kernel/sysctl: add panic_print into sysctl panic: add options to print system info when panic happens bfs: extra sanity checking and static inode bitmap exec: separate MM_ANONPAGES and RLIMIT_STACK accounting ...
2019-01-05dma-direct: fix DMA_ATTR_NO_KERNEL_MAPPING for remapped allocationsChristoph Hellwig1-6/+7
We need to return a dma_addr_t even if we don't have a kernel mapping. Do so by consolidating the phys_to_dma call in a single place and jump to it from all the branches that return successfully. Fixes: bfd56cd60521 ("dma-mapping: support highmem in the generic remap allocator") Reported-by: Liviu Dudau <[email protected] Signed-off-by: Christoph Hellwig <[email protected]> Tested-by: Liviu Dudau <[email protected]>
2019-01-04kernel/sched/: remove caller signal_pending branch predictionsDavidlohr Bueso3-3/+3
This is already done for us internally by the signal machinery. Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Davidlohr Bueso <[email protected]> Reviewed-by: Andrew Morton <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Ingo Molnar <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2019-01-04kernel/locking/mutex.c: remove caller signal_pending branch predictionsDavidlohr Bueso1-1/+1
This is already done for us internally by the signal machinery. Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Davidlohr Bueso <[email protected]> Reviewed-by: Andrew Morton <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Ingo Molnar <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2019-01-04kernel/kcov.c: mark write_comp_data() as notraceAnders Roxell1-1/+1
Since __sanitizer_cov_trace_const_cmp4 is marked as notrace, the function called from __sanitizer_cov_trace_const_cmp4 shouldn't be traceable either. ftrace_graph_caller() gets called every time func write_comp_data() gets called if it isn't marked 'notrace'. This is the backtrace from gdb: #0 ftrace_graph_caller () at ../arch/arm64/kernel/entry-ftrace.S:179 #1 0xffffff8010201920 in ftrace_caller () at ../arch/arm64/kernel/entry-ftrace.S:151 #2 0xffffff8010439714 in write_comp_data (type=5, arg1=0, arg2=0, ip=18446743524224276596) at ../kernel/kcov.c:116 #3 0xffffff8010439894 in __sanitizer_cov_trace_const_cmp4 (arg1=<optimized out>, arg2=<optimized out>) at ../kernel/kcov.c:188 #4 0xffffff8010201874 in prepare_ftrace_return (self_addr=18446743524226602768, parent=0xffffff801014b918, frame_pointer=18446743524223531344) at ./include/generated/atomic-instrumented.h:27 #5 0xffffff801020194c in ftrace_graph_caller () at ../arch/arm64/kernel/entry-ftrace.S:182 Rework so that write_comp_data() that are called from __sanitizer_cov_trace_*_cmp*() are marked as 'notrace'. Commit 903e8ff86753 ("kernel/kcov.c: mark funcs in __sanitizer_cov_trace_pc() as notrace") missed to mark write_comp_data() as 'notrace'. When that patch was created gcc-7 was used. In lib/Kconfig.debug config KCOV_ENABLE_COMPARISONS depends on $(cc-option,-fsanitize-coverage=trace-cmp) That code path isn't hit with gcc-7. However, it were that with gcc-8. Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Anders Roxell <[email protected]> Signed-off-by: Arnd Bergmann <[email protected]> Co-developed-by: Arnd Bergmann <[email protected]> Acked-by: Steven Rostedt (VMware) <[email protected]> Cc: Will Deacon <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2019-01-04kernel/sysctl: add panic_print into sysctlFeng Tang3-1/+9
So that we can also runtime chose to print out the needed system info for panic, other than setting the kernel cmdline. Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Feng Tang <[email protected]> Suggested-by: Steven Rostedt <[email protected]> Acked-by: Steven Rostedt (VMware) <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: John Stultz <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Kees Cook <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2019-01-04panic: add options to print system info when panic happensFeng Tang1-0/+28
Kernel panic issues are always painful to debug, partially because it's not easy to get enough information of the context when panic happens. And we have ramoops and kdump for that, while this commit tries to provide a easier way to show the system info by adding a cmdline parameter, referring some idea from sysrq handler. Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Feng Tang <[email protected]> Reviewed-by: Kees Cook <[email protected]> Acked-by: Steven Rostedt (VMware) <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: John Stultz <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Steven Rostedt <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2019-01-04fork: fix some -Wmissing-prototypes warningsYi Wang1-5/+0
We get a warning when building kernel with W=1: kernel/fork.c:167:13: warning: no previous prototype for `arch_release_thread_stack' [-Wmissing-prototypes] kernel/fork.c:779:13: warning: no previous prototype for `fork_init' [-Wmissing-prototypes] Add the missing declaration in head file to fix this. Also, remove arch_release_thread_stack() completely because no arch seems to implement it since bb9d81264 (arch: remove tile port). Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Yi Wang <[email protected]> Acked-by: Michal Hocko <[email protected]> Acked-by: Mike Rapoport <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2019-01-04kernel/hung_task.c: break RCU locks based on jiffiesTetsuo Handa1-4/+4
check_hung_uninterruptible_tasks() is currently calling rcu_lock_break() for every 1024 threads. But check_hung_task() is very slow if printk() was called, and is very fast otherwise. If many threads within some 1024 threads called printk(), the RCU grace period might be extended enough to trigger RCU stall warnings. Therefore, calling rcu_lock_break() for every some fixed jiffies will be safer. Link: http://lkml.kernel.org/r/1544800658-11423-1-git-send-email-penguin-kernel@I-love.SAKURA.ne.jp Signed-off-by: Tetsuo Handa <[email protected]> Acked-by: Paul E. McKenney <[email protected]> Cc: Petr Mladek <[email protected]> Cc: Sergey Senozhatsky <[email protected]> Cc: Dmitry Vyukov <[email protected]> Cc: "Rafael J. Wysocki" <[email protected]> Cc: Vitaly Kuznetsov <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
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