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An ipvlan bug fix in 'net' conflicted with the abstraction away
of the IPV6 specific support in 'net-next'.
Similarly, a bug fix for mlx5 in 'net' conflicted with the flow
action conversion in 'net-next'.
Signed-off-by: David S. Miller <davem@davemloft.net>
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Pull networking fixes from David Miller:
"This pull request is dedicated to the upcoming snowpocalypse parts 2
and 3 in the Pacific Northwest:
1) Drop profiles are broken because some drivers use dev_kfree_skb*
instead of dev_consume_skb*, from Yang Wei.
2) Fix IWLWIFI kconfig deps, from Luca Coelho.
3) Fix percpu maps updating in bpftool, from Paolo Abeni.
4) Missing station release in batman-adv, from Felix Fietkau.
5) Fix some networking compat ioctl bugs, from Johannes Berg.
6) ucc_geth must reset the BQL queue state when stopping the device,
from Mathias Thore.
7) Several XDP bug fixes in virtio_net from Toshiaki Makita.
8) TSO packets must be sent always on queue 0 in stmmac, from Jose
Abreu.
9) Fix socket refcounting bug in RDS, from Eric Dumazet.
10) Handle sparse cpu allocations in bpf selftests, from Martynas
Pumputis.
11) Make sure mgmt frames have enough tailroom in mac80211, from Felix
Feitkau.
12) Use safe list walking in sctp_sendmsg() asoc list traversal, from
Greg Kroah-Hartman.
13) Make DCCP's ccid_hc_[rt]x_parse_options always check for NULL
ccid, from Eric Dumazet.
14) Need to reload WoL password into bcmsysport device after deep
sleeps, from Florian Fainelli.
15) Remove filter from mask before freeing in cls_flower, from Petr
Machata.
16) Missing release and use after free in error paths of s390 qeth
code, from Julian Wiedmann.
17) Fix lockdep false positive in dsa code, from Marc Zyngier.
18) Fix counting of ATU violations in mv88e6xxx, from Andrew Lunn.
19) Fix EQ firmware assert in qed driver, from Manish Chopra.
20) Don't default Caivum PTP to Y in kconfig, from Bjorn Helgaas"
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (116 commits)
net: dsa: b53: Fix for failure when irq is not defined in dt
sit: check if IPv6 enabled before calling ip6_err_gen_icmpv6_unreach()
geneve: should not call rt6_lookup() when ipv6 was disabled
net: Don't default Cavium PTP driver to 'y'
net: broadcom: replace dev_kfree_skb_irq by dev_consume_skb_irq for drop profiles
net: via-velocity: replace dev_kfree_skb_irq by dev_consume_skb_irq for drop profiles
net: tehuti: replace dev_kfree_skb_irq by dev_consume_skb_irq for drop profiles
net: sun: replace dev_kfree_skb_irq by dev_consume_skb_irq for drop profiles
net: fsl_ucc_hdlc: replace dev_kfree_skb_irq by dev_consume_skb_irq for drop profiles
net: fec_mpc52xx: replace dev_kfree_skb_irq by dev_consume_skb_irq for drop profiles
net: smsc: epic100: replace dev_kfree_skb_irq by dev_consume_skb_irq for drop profiles
net: dscc4: replace dev_kfree_skb_irq by dev_consume_skb_irq for drop profiles
net: tulip: de2104x: replace dev_kfree_skb_irq by dev_consume_skb_irq for drop profiles
net: defxx: replace dev_kfree_skb_irq by dev_consume_skb_irq for drop profiles
net/mlx5e: Don't overwrite pedit action when multiple pedit used
net/mlx5e: Update hw flows when encap source mac changed
qed*: Advance drivers version to 8.37.0.20
qed: Change verbosity for coalescing message.
qede: Fix system crash on configuring channels.
qed: Consider TX tcs while deriving the max num_queues for PF.
...
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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 <davem@davemloft.net>
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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 <eric.dumazet@gmail.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
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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 <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
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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 <naresh.kamboju@linaro.org>
Reported-by: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
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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 <jannh@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
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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 <kafai@fb.com>
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core
Pull driver core fixes from Greg KH:
"Here are some driver core fixes for 5.0-rc6.
Well, not so much "driver core" as "debugfs". There's a lot of
outstanding debugfs cleanup patches coming in through different
subsystem trees, and in that process the debugfs core was found that
it really should return errors when something bad happens, to prevent
random files from showing up in the root of debugfs afterward. So
debugfs was fixed up to handle this properly, and then two fixes for
the relay and blk-mq code was needed as it was making invalid
assumptions about debugfs return values.
There's also a cacheinfo fix in here that resolves a tiny issue.
All of these have been in linux-next for over a week with no reported
problems"
* tag 'driver-core-5.0-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
blk-mq: protect debugfs_create_files() from failures
relay: check return of create_buf_file() properly
debugfs: debugfs_lookup() should return NULL if not found
debugfs: return error values, not NULL
debugfs: fix debugfs_rename parameter checking
cacheinfo: Keep the old value if of_property_read_u32 fails
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If create_buf_file() returns an error, don't try to reference it later
as a valid dentry pointer.
This problem was exposed when debugfs started to return errors instead
of just NULL for some calls when they do not succeed properly.
Also, the check for WARN_ON(dentry) was just wrong :)
Reported-by: Kees Cook <keescook@chromium.org>
Reported-and-tested-by: syzbot+16c3a70e1e9b29346c43@syzkaller.appspotmail.com
Reported-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: David Rientjes <rientjes@google.com>
Fixes: ff9fb72bc077 ("debugfs: return error values, not NULL")
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing fixes from Steven Rostedt:
"This has two fixes for uprobe code.
- Cut and paste fix to have uprobe printks say "uprobe" and not
"kprobe"
- Add terminating '\0' byte when copying function arguments"
* tag 'trace-v5.0-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
tracing/uprobes: Fix output for multiple string arguments
tracing: uprobes: Fix typo in pr_fmt string
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When printing multiple uprobe arguments as strings the output for the
earlier arguments would also include all later string arguments.
This is best explained in an example:
Consider adding a uprobe to a function receiving two strings as
parameters which is at offset 0xa0 in strlib.so and we want to print
both parameters when the uprobe is hit (on x86_64):
$ echo 'p:func /lib/strlib.so:0xa0 +0(%di):string +0(%si):string' > \
/sys/kernel/debug/tracing/uprobe_events
When the function is called as func("foo", "bar") and we hit the probe,
the trace file shows a line like the following:
[...] func: (0x7f7e683706a0) arg1="foobar" arg2="bar"
Note the extra "bar" printed as part of arg1. This behaviour stacks up
for additional string arguments.
The strings are stored in a dynamically growing part of the uprobe
buffer by fetch_store_string() after copying them from userspace via
strncpy_from_user(). The return value of strncpy_from_user() is then
directly used as the required size for the string. However, this does
not take the terminating null byte into account as the documentation
for strncpy_from_user() cleary states that it "[...] returns the
length of the string (not including the trailing NUL)" even though the
null byte will be copied to the destination.
Therefore, subsequent calls to fetch_store_string() will overwrite
the terminating null byte of the most recently fetched string with
the first character of the current string, leading to the
"accumulation" of strings in earlier arguments in the output.
Fix this by incrementing the return value of strncpy_from_user() by
one if we did not hit the maximum buffer size.
Link: http://lkml.kernel.org/r/20190116141629.5752-1-andreas.ziegler@fau.de
Cc: Ingo Molnar <mingo@redhat.com>
Cc: stable@vger.kernel.org
Fixes: 5baaa59ef09e ("tracing/probes: Implement 'memory' fetch method for uprobes")
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Andreas Ziegler <andreas.ziegler@fau.de>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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The subsystem-specific message prefix for uprobes was also
"trace_kprobe: " instead of "trace_uprobe: " as described in
the original commit message.
Link: http://lkml.kernel.org/r/20190117133023.19292-1-andreas.ziegler@fau.de
Cc: Ingo Molnar <mingo@redhat.com>
Cc: stable@vger.kernel.org
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Fixes: 7257634135c24 ("tracing/probe: Show subsystem name in messages")
Signed-off-by: Andreas Ziegler <andreas.ziegler@fau.de>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull cpu hotplug fixes from Thomas Gleixner:
"Two fixes for the cpu hotplug machinery:
- Replace the overly clever 'SMT disabled by BIOS' detection logic as
it breaks KVM scenarios and prevents speculation control updates
when the Hyperthreads are brought online late after boot.
- Remove a redundant invocation of the speculation control update
function"
* 'smp-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
cpu/hotplug: Fix "SMT disabled by BIOS" detection for KVM
x86/speculation: Remove redundant arch_smt_update() invocation
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With the following commit:
73d5e2b47264 ("cpu/hotplug: detect SMT disabled by BIOS")
... the hotplug code attempted to detect when SMT was disabled by BIOS,
in which case it reported SMT as permanently disabled. However, that
code broke a virt hotplug scenario, where the guest is booted with only
primary CPU threads, and a sibling is brought online later.
The problem is that there doesn't seem to be a way to reliably
distinguish between the HW "SMT disabled by BIOS" case and the virt
"sibling not yet brought online" case. So the above-mentioned commit
was a bit misguided, as it permanently disabled SMT for both cases,
preventing future virt sibling hotplugs.
Going back and reviewing the original problems which were attempted to
be solved by that commit, when SMT was disabled in BIOS:
1) /sys/devices/system/cpu/smt/control showed "on" instead of
"notsupported"; and
2) vmx_vm_init() was incorrectly showing the L1TF_MSG_SMT warning.
I'd propose that we instead consider #1 above to not actually be a
problem. Because, at least in the virt case, it's possible that SMT
wasn't disabled by BIOS and a sibling thread could be brought online
later. So it makes sense to just always default the smt control to "on"
to allow for that possibility (assuming cpuid indicates that the CPU
supports SMT).
The real problem is #2, which has a simple fix: change vmx_vm_init() to
query the actual current SMT state -- i.e., whether any siblings are
currently online -- instead of looking at the SMT "control" sysfs value.
So fix it by:
a) reverting the original "fix" and its followup fix:
73d5e2b47264 ("cpu/hotplug: detect SMT disabled by BIOS")
bc2d8d262cba ("cpu/hotplug: Fix SMT supported evaluation")
and
b) changing vmx_vm_init() to query the actual current SMT state --
instead of the sysfs control value -- to determine whether the L1TF
warning is needed. This also requires the 'sched_smt_present'
variable to exported, instead of 'cpu_smt_control'.
Fixes: 73d5e2b47264 ("cpu/hotplug: detect SMT disabled by BIOS")
Reported-by: Igor Mammedov <imammedo@redhat.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Joe Mario <jmario@redhat.com>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: kvm@vger.kernel.org
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/e3a85d585da28cc333ecbc1e78ee9216e6da9396.1548794349.git.jpoimboe@redhat.com
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With commit a74cfffb03b7 ("x86/speculation: Rework SMT state change"),
arch_smt_update() is invoked from each individual CPU hotplug function.
Therefore the extra arch_smt_update() call in the sysfs SMT control is
redundant.
Fixes: a74cfffb03b7 ("x86/speculation: Rework SMT state change")
Signed-off-by: Zhenzhong Duan <zhenzhong.duan@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: <konrad.wilk@oracle.com>
Cc: <dwmw@amazon.co.uk>
Cc: <bp@suse.de>
Cc: <srinivas.eeda@oracle.com>
Cc: <peterz@infradead.org>
Cc: <hpa@zytor.com>
Link: https://lkml.kernel.org/r/e2e064f2-e8ef-42ca-bf4f-76b612964752@default
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf fixes from Thomas Gleixner:
"A pile of perf updates:
- Fix broken sanity check in the /proc/sys/kernel/perf_cpu_time_max_percent
write handler
- Cure a perf script crash which caused by an unitinialized data
structure
- Highlight the hottest instruction in perf top and not a random one
- Cure yet another clang issue when building perf python
- Handle topology entries with no CPU correctly in the tools
- Handle perf data which contains both tracepoints and performance
counter entries correctly.
- Add a missing NULL pointer check in perf ordered_events_free()"
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf script: Fix crash when processing recorded stat data
perf top: Fix wrong hottest instruction highlighted
perf tools: Handle TOPOLOGY headers with no CPU
perf python: Remove -fstack-clash-protection when building with some clang versions
perf core: Fix perf_proc_update_handler() bug
perf script: Fix crash with printing mixed trace point and other events
perf ordered_events: Fix crash in ordered_events__free
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git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/urgent
Pull perf/urgent fixes from Arnaldo Carvalho de Melo:
Kernel:
Stephane Eranian:
- Fix perf_proc_update_handler() bug.
perf script:
Andi Kleen:
- Fix crash with printing mixed trace point and other events.
Tony Jones:
- Fix crash when processing recorded stat data.
perf top:
He Kuang:
- Fix wrong hottest instruction highlighted.
perf python:
Arnaldo Carvalho de Melo:
- Remove -fstack-clash-protection when building with some clang versions.
perf ordered_events:
Jiri Olsa:
- Fix out of buffers crash in ordered_events__free().
perf cpu_map:
Stephane Eranian:
- Handle TOPOLOGY headers with no CPU.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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The perf_proc_update_handler() handles /proc/sys/kernel/perf_event_max_sample_rate
syctl variable. When the PMU IRQ handler timing monitoring is disabled, i.e,
when /proc/sys/kernel/perf_cpu_time_max_percent is equal to 0 or 100,
then no modification to sysctl_perf_event_sample_rate is allowed to prevent
possible hang from wrong values.
The problem is that the test to prevent modification is made after the
sysctl variable is modified in perf_proc_update_handler().
You get an error:
$ echo 10001 >/proc/sys/kernel/perf_event_max_sample_rate
echo: write error: invalid argument
But the value is still modified causing all sorts of inconsistencies:
$ cat /proc/sys/kernel/perf_event_max_sample_rate
10001
This patch fixes the problem by moving the parsing of the value after
the test.
Committer testing:
# echo 100 > /proc/sys/kernel/perf_cpu_time_max_percent
# echo 10001 > /proc/sys/kernel/perf_event_max_sample_rate
-bash: echo: write error: Invalid argument
# cat /proc/sys/kernel/perf_event_max_sample_rate
10001
#
Signed-off-by: Stephane Eranian <eranian@google.com>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Reviewed-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1547169436-6266-1-git-send-email-eranian@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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psi has provisions to shut off the periodic aggregation worker when
there is a period of no task activity - and thus no data that needs
aggregating. However, while developing psi monitoring, Suren noticed
that the aggregation clock currently won't stay shut off for good.
Debugging this revealed a flaw in the idle design: an aggregation run
will see no task activity and decide to go to sleep; shortly thereafter,
the kworker thread that executed the aggregation will go idle and cause
a scheduling change, during which the psi callback will kick the
!pending worker again. This will ping-pong forever, and is equivalent
to having no shut-off logic at all (but with more code!)
Fix this by exempting aggregation workers from psi's clock waking logic
when the state change is them going to sleep. To do this, tag workers
with the last work function they executed, and if in psi we see a worker
going to sleep after aggregating psi data, we will not reschedule the
aggregation work item.
What if the worker is also executing other items before or after?
Any psi state times that were incurred by work items preceding the
aggregation work will have been collected from the per-cpu buckets
during the aggregation itself. If there are work items following the
aggregation work, the worker's last_func tag will be overwritten and the
aggregator will be kept alive to process this genuine new activity.
If the aggregation work is the last thing the worker does, and we decide
to go idle, the brief period of non-idle time incurred between the
aggregation run and the kworker's dequeue will be stranded in the
per-cpu buckets until the clock is woken by later activity. But that
should not be a problem. The buckets can hold 4s worth of time, and
future activity will wake the clock with a 2s delay, giving us 2s worth
of data we can leave behind when disabling aggregation. If it takes a
worker more than two seconds to go idle after it finishes its last work
item, we likely have bigger problems in the system, and won't notice one
sample that was averaged with a bogus per-CPU weight.
Link: http://lkml.kernel.org/r/20190116193501.1910-1-hannes@cmpxchg.org
Fixes: eb414681d5a0 ("psi: pressure stall information for CPU, memory, and IO")
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reported-by: Suren Baghdasaryan <surenb@google.com>
Acked-by: Tejun Heo <tj@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Currently, exit_ptrace() adds all ptraced tasks in a dead list, then
zap_pid_ns_processes() waits on all tasks in a current pidns, and only
then are tasks from the dead list released.
zap_pid_ns_processes() can get stuck on waiting tasks from the dead
list. In this case, we will have one unkillable process with one or
more dead children.
Thanks to Oleg for the advice to release tasks in find_child_reaper().
Link: http://lkml.kernel.org/r/20190110175200.12442-1-avagin@gmail.com
Fixes: 7c8bd2322c7f ("exit: ptrace: shift "reap dead" code from exit_ptrace() to forget_original_parent()")
Signed-off-by: Andrei Vagin <avagin@gmail.com>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Introduce BPF_F_LOCK flag for map_lookup and map_update syscall commands
and for map_update() helper function.
In all these cases take a lock of existing element (which was provided
in BTF description) before copying (in or out) the rest of map value.
Implementation details that are part of uapi:
Array:
The array map takes the element lock for lookup/update.
Hash:
hash map also takes the lock for lookup/update and tries to avoid the bucket lock.
If old element exists it takes the element lock and updates the element in place.
If element doesn't exist it allocates new one and inserts into hash table
while holding the bucket lock.
In rare case the hashmap has to take both the bucket lock and the element lock
to update old value in place.
Cgroup local storage:
It is similar to array. update in place and lookup are done with lock taken.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
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Allow 'struct bpf_spin_lock' to reside inside cgroup local storage.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
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Introduce 'struct bpf_spin_lock' and bpf_spin_lock/unlock() helpers to let
bpf program serialize access to other variables.
Example:
struct hash_elem {
int cnt;
struct bpf_spin_lock lock;
};
struct hash_elem * val = bpf_map_lookup_elem(&hash_map, &key);
if (val) {
bpf_spin_lock(&val->lock);
val->cnt++;
bpf_spin_unlock(&val->lock);
}
Restrictions and safety checks:
- bpf_spin_lock is only allowed inside HASH and ARRAY maps.
- BTF description of the map is mandatory for safety analysis.
- bpf program can take one bpf_spin_lock at a time, since two or more can
cause dead locks.
- only one 'struct bpf_spin_lock' is allowed per map element.
It drastically simplifies implementation yet allows bpf program to use
any number of bpf_spin_locks.
- when bpf_spin_lock is taken the calls (either bpf2bpf or helpers) are not allowed.
- bpf program must bpf_spin_unlock() before return.
- bpf program can access 'struct bpf_spin_lock' only via
bpf_spin_lock()/bpf_spin_unlock() helpers.
- load/store into 'struct bpf_spin_lock lock;' field is not allowed.
- to use bpf_spin_lock() helper the BTF description of map value must be
a struct and have 'struct bpf_spin_lock anyname;' field at the top level.
Nested lock inside another struct is not allowed.
- syscall map_lookup doesn't copy bpf_spin_lock field to user space.
- syscall map_update and program map_update do not update bpf_spin_lock field.
- bpf_spin_lock cannot be on the stack or inside networking packet.
bpf_spin_lock can only be inside HASH or ARRAY map value.
- bpf_spin_lock is available to root only and to all program types.
- bpf_spin_lock is not allowed in inner maps of map-in-map.
- ld_abs is not allowed inside spin_lock-ed region.
- tracing progs and socket filter progs cannot use bpf_spin_lock due to
insufficient preemption checks
Implementation details:
- cgroup-bpf class of programs can nest with xdp/tc programs.
Hence bpf_spin_lock is equivalent to spin_lock_irqsave.
Other solutions to avoid nested bpf_spin_lock are possible.
Like making sure that all networking progs run with softirq disabled.
spin_lock_irqsave is the simplest and doesn't add overhead to the
programs that don't use it.
- arch_spinlock_t is used when its implemented as queued_spin_lock
- archs can force their own arch_spinlock_t
- on architectures where queued_spin_lock is not available and
sizeof(arch_spinlock_t) != sizeof(__u32) trivial lock is used.
- presence of bpf_spin_lock inside map value could have been indicated via
extra flag during map_create, but specifying it via BTF is cleaner.
It provides introspection for map key/value and reduces user mistakes.
Next steps:
- allow bpf_spin_lock in other map types (like cgroup local storage)
- introduce BPF_F_LOCK flag for bpf_map_update() syscall and helper
to request kernel to grab bpf_spin_lock before rewriting the value.
That will serialize access to map elements.
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
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Building with W=1 reveals some bitrot:
CC kernel/bpf/cgroup.o
kernel/bpf/cgroup.c:238: warning: Function parameter or member 'flags' not described in '__cgroup_bpf_attach'
kernel/bpf/cgroup.c:367: warning: Function parameter or member 'unused_flags' not described in '__cgroup_bpf_detach'
Add a kerneldoc line for 'flags'.
Fixing the warning for 'unused_flags' is best approached by
removing the unused parameter on the function call.
Signed-off-by: Valdis Kletnieks <valdis.kletnieks@vt.edu>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
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Over the years, the function signature has changed, but the
kerneldoc block hasn't.
Signed-off-by: Valdis Kletnieks <valdis.kletnieks@vt.edu>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
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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
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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 <hjl.tools@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20190111133500.840117406@linutronix.de
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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
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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 <xieyongji@baidu.com>
Signed-off-by: Zhang Yu <zhangyu31@baidu.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>
Fixes: e38513905eea ("locking/rwsem: Rework zeroing reader waiter->task")
Link: https://lkml.kernel.org/r/1543495830-2644-1-git-send-email-xieyongji@baidu.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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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) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: 1d0dcb3ad9d3 ("futex: Implement lockless wakeups")
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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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 <elohimes@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Waiman Long <longman@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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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 <elohimes@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Waiman Long <longman@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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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
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| [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 <prsood@codeaurora.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Andrea Parri <andrea.parri@amarulasolutions.com>
Acked-by: Davidlohr Bueso <dbueso@suse.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: 8f95c90ceb54 ("sched/wait, RCU: Introduce rcuwait machinery")
Link: https://lkml.kernel.org/r/1543590656-7157-1-git-send-email-prsood@codeaurora.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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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
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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 <chenhc@lemote.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Fuxin Zhang <zhangfx@lemote.com>
Cc: Zhangjin Wu <wuzhangjin@gmail.com>
Cc: Huacai Chen <chenhuacai@gmail.com>
Cc: Dou Liyang <douliyangs@gmail.com>
Link: https://lkml.kernel.org/r/1547694009-16261-1-git-send-email-chenhc@lemote.com
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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 <sramana@codeaurora.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-arm-msm@vger.kernel.org
Link: https://lkml.kernel.org/r/1545312957-8504-1-git-send-email-sramana@codeaurora.org
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Daniel Borkmann says:
====================
pull-request: bpf-next 2019-01-29
The following pull-request contains BPF updates for your *net-next* tree.
The main changes are:
1) Teach verifier dead code removal, this also allows for optimizing /
removing conditional branches around dead code and to shrink the
resulting image. Code store constrained architectures like nfp would
have hard time doing this at JIT level, from Jakub.
2) Add JMP32 instructions to BPF ISA in order to allow for optimizing
code generation for 32-bit sub-registers. Evaluation shows that this
can result in code reduction of ~5-20% compared to 64 bit-only code
generation. Also add implementation for most JITs, from Jiong.
3) Add support for __int128 types in BTF which is also needed for
vmlinux's BTF conversion to work, from Yonghong.
4) Add a new command to bpftool in order to dump a list of BPF-related
parameters from the system or for a specific network device e.g. in
terms of available prog/map types or helper functions, from Quentin.
5) Add AF_XDP sock_diag interface for querying sockets from user
space which provides information about the RX/TX/fill/completion
rings, umem, memory usage etc, from Björn.
6) Add skb context access for skb_shared_info->gso_segs field, from Eric.
7) Add support for testing flow dissector BPF programs by extending
existing BPF_PROG_TEST_RUN infrastructure, from Stanislav.
8) Split BPF kselftest's test_verifier into various subgroups of tests
in order better deal with merge conflicts in this area, from Jakub.
9) Add support for queue/stack manipulations in bpftool, from Stanislav.
10) Document BTF, from Yonghong.
11) Dump supported ELF section names in libbpf on program load
failure, from Taeung.
12) Silence a false positive compiler warning in verifier's BTF
handling, from Peter.
13) Fix help string in bpftool's feature probing, from Prashant.
14) Remove duplicate includes in BPF kselftests, from Yue.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
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This patch adds JIT blinds support for JMP32.
Like BPF_JMP_REG/IMM, JMP32 version are needed for building raw bpf insn.
They are added to both include/linux/filter.h and
tools/include/linux/filter.h.
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Jiong Wang <jiong.wang@netronome.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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This patch implements interpreting new JMP32 instructions.
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Jiong Wang <jiong.wang@netronome.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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This patch teaches disassembler about JMP32. There are two places to
update:
- Class 0x6 now used by BPF_JMP32, not "unused".
- BPF_JMP32 need to show comparison operands properly.
The disassemble format is to add an extra "(32)" before the operands if
it is a sub-register. A better disassemble format for both JMP32 and
ALU32 just show the register prefix as "w" instead of "r", this is the
format using by LLVM assembler.
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Jiong Wang <jiong.wang@netronome.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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This patch teach verifier about the new BPF_JMP32 instruction class.
Verifier need to treat it similar as the existing BPF_JMP class.
A BPF_JMP32 insn needs to go through all checks that have been done on
BPF_JMP.
Also, verifier is doing runtime optimizations based on the extra info
conditional jump instruction could offer, especially when the comparison is
between constant and register that the value range of the register could be
improved based on the comparison results. These code are updated
accordingly.
Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Jiong Wang <jiong.wang@netronome.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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The current min/max code does both signed and unsigned comparisons against
the input argument "val" which is "u64" and there is explicit type casting
when the comparison is signed.
As we will need slightly more complexer type casting when JMP32 introduced,
it is better to host the signed type casting. This makes the code more
clean with ignorable runtime overhead.
Also, code for J*GE/GT/LT/LE and JEQ/JNE are very similar, this patch
combine them.
The main purpose for this refactor is to make sure the min/max code will
still be readable and with minimum code duplication after JMP32 introduced.
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Jiong Wang <jiong.wang@netronome.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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Let offload JITs know when instructions are replaced and optimized
out, so they can update their state appropriately. The optimizations
are best effort, if JIT returns an error from any callback verifier
will stop notifying it as state may now be out of sync, but the
verifier continues making progress.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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The communication between the verifier and advanced JITs is based
on instruction indexes. We have to keep them stable throughout
the optimizations otherwise referring to a particular instruction
gets messy quickly.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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Unconditional branches by 0 instructions are basically noops
but they can result from earlier optimizations, e.g. a conditional
jumps which would never be taken or a conditional jump around
dead code.
Remove those branches.
v0.2:
- s/opt_remove_dead_branches/opt_remove_nops/ (Jiong).
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Jiong Wang <jiong.wang@netronome.com>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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Instead of overwriting dead code with jmp -1 instructions
remove it completely for root. Adjust verifier state and
line info appropriately.
v2:
- adjust func_info (Alexei);
- make sure first instruction retains line info (Alexei).
v4: (Yonghong)
- remove unnecessary if (!insn to remove) checks;
- always keep last line info if first live instruction lacks one.
v5: (Martin Lau)
- improve and clarify comments.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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Loading programs with dead code becomes more and more
common, as people begin to patch constants at load time.
Turn conditional jumps to unconditional ones, to avoid
potential branch misprediction penalty.
This optimization is enabled for privileged users only.
For branches which just fall through we could just mark
them as not seen and have dead code removal take care of
them, but that seems less clean.
v0.2:
- don't call capable(CAP_SYS_ADMIN) twice (Jiong).
v3:
- fix GCC warning;
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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In preparation for code removal change parameters to branch
and call adjustment functions to be more universal. The
current parameters assume we are patching a single instruction
with a longer set.
A diagram may help reading the change, this is for the patch
single case, patching instruction 1 with a replacement of 4:
____
0 |____|
1 |____| <-- pos ^
2 | | <-- end old ^ |
3 | | | delta | len
4 |____| | | (patch region)
5 | | <-- end new v v
6 |____|
end_old = pos + 1
end_new = pos + delta + 1
If we are before the patch region - curr variable and the target
are fully in old coordinates (hence comparing against end_old).
If we are after the region curr is in new coordinates (hence
the comparison to end_new) but target is in mixed coordinates,
so we just check if it falls before end_new, and if so it needs
the adjustment.
Note that we will not fix up branches which land in removed region
in case of removal, which should be okay, as we are only going to
remove dead code.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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