Commit Graph

34753 Commits

Author SHA1 Message Date
Linus Torvalds f4b936f5d6 A couple of scheduler fixes:
- Make the conditional update of the overutilized state work correctly by
    caching the relevant flags state before overwriting them and checking
    them afterwards.
 
  - Fix a data race in the wakeup path which caused loadavg on ARM64
    platforms to become a random number generator.
 
  - Fix the ordering of the iowaiter accounting operations so it can't be
    decremented before it is incremented.
 
  - Fix a bug in the deadline scheduler vs. priority inheritance when a
    non-deadline task A has inherited the parameters of a deadline task B
    and then blocks on a non-deadline task C.
 
    The second inheritance step used the static deadline parameters of task
    A, which are usually 0, instead of further propagating task B's
    parameters. The zero initialized parameters trigger a bug in the
    deadline scheduler.
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Merge tag 'sched-urgent-2020-11-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull scheduler fixes from Thomas Gleixner:
 "A couple of scheduler fixes:

   - Make the conditional update of the overutilized state work
     correctly by caching the relevant flags state before overwriting
     them and checking them afterwards.

   - Fix a data race in the wakeup path which caused loadavg on ARM64
     platforms to become a random number generator.

   - Fix the ordering of the iowaiter accounting operations so it can't
     be decremented before it is incremented.

   - Fix a bug in the deadline scheduler vs. priority inheritance when a
     non-deadline task A has inherited the parameters of a deadline task
     B and then blocks on a non-deadline task C.

     The second inheritance step used the static deadline parameters of
     task A, which are usually 0, instead of further propagating task
     B's parameters. The zero initialized parameters trigger a bug in
     the deadline scheduler"

* tag 'sched-urgent-2020-11-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/deadline: Fix priority inheritance with multiple scheduling classes
  sched: Fix rq->nr_iowait ordering
  sched: Fix data-race in wakeup
  sched/fair: Fix overutilized update in enqueue_task_fair()
2020-11-22 13:26:07 -08:00
Linus Torvalds 855cf1ee47 A single fix for lockdep which makes the recursion protection cover graph
lock/unlock.
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Merge tag 'locking-urgent-2020-11-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull locking fix from Thomas Gleixner:
 "A single fix for lockdep which makes the recursion protection cover
  graph lock/unlock"

* tag 'locking-urgent-2020-11-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  lockdep: Put graph lock/unlock under lock_recursion protection
2020-11-22 13:19:53 -08:00
Linus Torvalds ea0ab64306 seccomp fixes for v5.10-rc5
- Fix typos in seccomp selftests on powerpc and sh (Kees Cook)
 
 - Fix PF_SUPERPRIV audit marking in seccomp and ptrace (Mickaël Salaün)
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Merge tag 'seccomp-v5.10-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull seccomp fixes from Kees Cook:
 "This gets the seccomp selftests running again on powerpc and sh, and
  fixes an audit reporting oversight noticed in both seccomp and ptrace.

   - Fix typos in seccomp selftests on powerpc and sh (Kees Cook)

   - Fix PF_SUPERPRIV audit marking in seccomp and ptrace (Mickaël
     Salaün)"

* tag 'seccomp-v5.10-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  selftests/seccomp: sh: Fix register names
  selftests/seccomp: powerpc: Fix typo in macro variable name
  seccomp: Set PF_SUPERPRIV when checking capability
  ptrace: Set PF_SUPERPRIV when checking capability
2020-11-21 10:24:05 -08:00
Linus Torvalds 4d02da974e Networking fixes for 5.10-rc5, including fixes from the WiFi (mac80211),
can and bpf (including the strncpy_from_user fix).
 
 Current release - regressions:
 
  - mac80211: fix memory leak of filtered powersave frames
 
  - mac80211: free sta in sta_info_insert_finish() on errors to avoid
              sleeping in atomic context
 
  - netlabel: fix an uninitialized variable warning added in -rc4
 
 Previous release - regressions:
 
  - vsock: forward all packets to the host when no H2G is registered,
            un-breaking AWS Nitro Enclaves
 
  - net: Exempt multicast addresses from five-second neighbor lifetime
         requirement, decreasing the chances neighbor tables fill up
 
  - net/tls: fix corrupted data in recvmsg
 
  - qed: fix ILT configuration of SRC block
 
  - can: m_can: process interrupt only when not runtime suspended
 
 Previous release - always broken:
 
  - page_frag: Recover from memory pressure by not recycling pages
               allocating from the reserves
 
  - strncpy_from_user: Mask out bytes after NUL terminator
 
  - ip_tunnels: Set tunnel option flag only when tunnel metadata is
                present, always setting it confuses Open vSwitch
 
  - bpf, sockmap:
    - Fix partial copy_page_to_iter so progress can still be made
    - Fix socket memory accounting and obeying SO_RCVBUF
 
  - net: Have netpoll bring-up DSA management interface
 
  - net: bridge: add missing counters to ndo_get_stats64 callback
 
  - tcp: brr: only postpone PROBE_RTT if RTT is < current min_rtt
 
  - enetc: Workaround MDIO register access HW bug
 
  - net/ncsi: move netlink family registration to a subsystem init,
              instead of tying it to driver probe
 
  - net: ftgmac100: unregister NC-SI when removing driver to avoid crash
 
  - lan743x: prevent interrupt storm on open
 
  - lan743x: fix freeing skbs in the wrong context
 
  - net/mlx5e: Fix socket refcount leak on kTLS RX resync
 
  - net: dsa: mv88e6xxx: Avoid VLAN database corruption on 6097
 
  - fix 21 unset return codes and other mistakes on error paths,
    mostly detected by the Hulk Robot
 
 Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Merge tag 'net-5.10-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

Pull networking fixes from Jakub Kicinski:
 "Networking fixes for 5.10-rc5, including fixes from the WiFi
  (mac80211), can and bpf (including the strncpy_from_user fix).

  Current release - regressions:

   - mac80211: fix memory leak of filtered powersave frames

   - mac80211: free sta in sta_info_insert_finish() on errors to avoid
     sleeping in atomic context

   - netlabel: fix an uninitialized variable warning added in -rc4

  Previous release - regressions:

   - vsock: forward all packets to the host when no H2G is registered,
     un-breaking AWS Nitro Enclaves

   - net: Exempt multicast addresses from five-second neighbor lifetime
     requirement, decreasing the chances neighbor tables fill up

   - net/tls: fix corrupted data in recvmsg

   - qed: fix ILT configuration of SRC block

   - can: m_can: process interrupt only when not runtime suspended

  Previous release - always broken:

   - page_frag: Recover from memory pressure by not recycling pages
     allocating from the reserves

   - strncpy_from_user: Mask out bytes after NUL terminator

   - ip_tunnels: Set tunnel option flag only when tunnel metadata is
     present, always setting it confuses Open vSwitch

   - bpf, sockmap:
      - Fix partial copy_page_to_iter so progress can still be made
      - Fix socket memory accounting and obeying SO_RCVBUF

   - net: Have netpoll bring-up DSA management interface

   - net: bridge: add missing counters to ndo_get_stats64 callback

   - tcp: brr: only postpone PROBE_RTT if RTT is < current min_rtt

   - enetc: Workaround MDIO register access HW bug

   - net/ncsi: move netlink family registration to a subsystem init,
     instead of tying it to driver probe

   - net: ftgmac100: unregister NC-SI when removing driver to avoid
     crash

   - lan743x:
      - prevent interrupt storm on open
      - fix freeing skbs in the wrong context

   - net/mlx5e: Fix socket refcount leak on kTLS RX resync

   - net: dsa: mv88e6xxx: Avoid VLAN database corruption on 6097

   - fix 21 unset return codes and other mistakes on error paths, mostly
     detected by the Hulk Robot"

* tag 'net-5.10-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (115 commits)
  fail_function: Remove a redundant mutex unlock
  selftest/bpf: Test bpf_probe_read_user_str() strips trailing bytes after NUL
  lib/strncpy_from_user.c: Mask out bytes after NUL terminator.
  net/smc: fix direct access to ib_gid_addr->ndev in smc_ib_determine_gid()
  net/smc: fix matching of existing link groups
  ipv6: Remove dependency of ipv6_frag_thdr_truncated on ipv6 module
  libbpf: Fix VERSIONED_SYM_COUNT number parsing
  net/mlx4_core: Fix init_hca fields offset
  atm: nicstar: Unmap DMA on send error
  page_frag: Recover from memory pressure
  net: dsa: mv88e6xxx: Wait for EEPROM done after HW reset
  mlxsw: core: Use variable timeout for EMAD retries
  mlxsw: Fix firmware flashing
  net: Have netpoll bring-up DSA management interface
  atl1e: fix error return code in atl1e_probe()
  atl1c: fix error return code in atl1c_probe()
  ah6: fix error return code in ah6_input()
  net: usb: qmi_wwan: Set DTR quirk for MR400
  can: m_can: process interrupt only when not runtime suspended
  can: flexcan: flexcan_chip_start(): fix erroneous flexcan_transceiver_enable() during bus-off recovery
  ...
2020-11-19 13:33:16 -08:00
Jakub Kicinski e6ea60bac1 Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf
Alexei Starovoitov says:

====================
1) libbpf should not attempt to load unused subprogs, from Andrii.

2) Make strncpy_from_user() mask out bytes after NUL terminator, from Daniel.

3) Relax return code check for subprograms in the BPF verifier, from Dmitrii.

4) Fix several sockmap issues, from John.

* https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf:
  fail_function: Remove a redundant mutex unlock
  selftest/bpf: Test bpf_probe_read_user_str() strips trailing bytes after NUL
  lib/strncpy_from_user.c: Mask out bytes after NUL terminator.
  libbpf: Fix VERSIONED_SYM_COUNT number parsing
  bpf, sockmap: Avoid failures from skb_to_sgvec when skb has frag_list
  bpf, sockmap: Handle memory acct if skb_verdict prog redirects to self
  bpf, sockmap: Avoid returning unneeded EAGAIN when redirecting to self
  bpf, sockmap: Use truesize with sk_rmem_schedule()
  bpf, sockmap: Ensure SO_RCVBUF memory is observed on ingress redirect
  bpf, sockmap: Fix partial copy_page_to_iter so progress can still be made
  selftests/bpf: Fix error return code in run_getsockopt_test()
  bpf: Relax return code check for subprograms
  tools, bpftool: Add missing close before bpftool net attach exit
  MAINTAINERS/bpf: Update Andrii's entry.
  selftests/bpf: Fix unused attribute usage in subprogs_unused test
  bpf: Fix unsigned 'datasec_id' compared with zero in check_pseudo_btf_id
  bpf: Fix passing zero to PTR_ERR() in bpf_btf_printf_prepare
  libbpf: Don't attempt to load unused subprog as an entry-point BPF program
====================

Link: https://lore.kernel.org/r/20201119200721.288-1-alexei.starovoitov@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-11-19 12:26:10 -08:00
Luo Meng 2801a5da5b fail_function: Remove a redundant mutex unlock
Fix a mutex_unlock() issue where before copy_from_user() is
not called mutex_locked.

Fixes: 4b1a29a7f5 ("error-injection: Support fault injection framework")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Luo Meng <luomeng12@huawei.com>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Link: https://lore.kernel.org/bpf/160570737118.263807.8358435412898356284.stgit@devnote2
2020-11-19 11:58:16 -08:00
Daniel Xu 6fa6d28051 lib/strncpy_from_user.c: Mask out bytes after NUL terminator.
do_strncpy_from_user() may copy some extra bytes after the NUL
terminator into the destination buffer. This usually does not matter for
normal string operations. However, when BPF programs key BPF maps with
strings, this matters a lot.

A BPF program may read strings from user memory by calling the
bpf_probe_read_user_str() helper which eventually calls
do_strncpy_from_user(). The program can then key a map with the
destination buffer. BPF map keys are fixed-width and string-agnostic,
meaning that map keys are treated as a set of bytes.

The issue is when do_strncpy_from_user() overcopies bytes after the NUL
terminator, it can result in seemingly identical strings occupying
multiple slots in a BPF map. This behavior is subtle and totally
unexpected by the user.

This commit masks out the bytes following the NUL while preserving
long-sized stride in the fast path.

Fixes: 6ae08ae3de ("bpf: Add probe_read_{user, kernel} and probe_read_{user, kernel}_str helpers")
Signed-off-by: Daniel Xu <dxu@dxuuu.xyz>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/21efc982b3e9f2f7b0379eed642294caaa0c27a7.1605642949.git.dxu@dxuuu.xyz
2020-11-19 11:56:16 -08:00
Mickaël Salaün fb14528e44 seccomp: Set PF_SUPERPRIV when checking capability
Replace the use of security_capable(current_cred(), ...) with
ns_capable_noaudit() which set PF_SUPERPRIV.

Since commit 98f368e9e2 ("kernel: Add noaudit variant of
ns_capable()"), a new ns_capable_noaudit() helper is available.  Let's
use it!

Cc: Jann Horn <jannh@google.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Tyler Hicks <tyhicks@linux.microsoft.com>
Cc: Will Drewry <wad@chromium.org>
Cc: stable@vger.kernel.org
Fixes: e2cfabdfd0 ("seccomp: add system call filtering using BPF")
Signed-off-by: Mickaël Salaün <mic@linux.microsoft.com>
Reviewed-by: Jann Horn <jannh@google.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20201030123849.770769-3-mic@digikod.net
2020-11-17 12:53:22 -08:00
Mickaël Salaün cf23705244 ptrace: Set PF_SUPERPRIV when checking capability
Commit 69f594a389 ("ptrace: do not audit capability check when outputing
/proc/pid/stat") replaced the use of ns_capable() with
has_ns_capability{,_noaudit}() which doesn't set PF_SUPERPRIV.

Commit 6b3ad6649a ("ptrace: reintroduce usage of subjective credentials in
ptrace_has_cap()") replaced has_ns_capability{,_noaudit}() with
security_capable(), which doesn't set PF_SUPERPRIV neither.

Since commit 98f368e9e2 ("kernel: Add noaudit variant of ns_capable()"), a
new ns_capable_noaudit() helper is available.  Let's use it!

As a result, the signature of ptrace_has_cap() is restored to its original one.

Cc: Christian Brauner <christian.brauner@ubuntu.com>
Cc: Eric Paris <eparis@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Serge E. Hallyn <serge@hallyn.com>
Cc: Tyler Hicks <tyhicks@linux.microsoft.com>
Cc: stable@vger.kernel.org
Fixes: 6b3ad6649a ("ptrace: reintroduce usage of subjective credentials in ptrace_has_cap()")
Fixes: 69f594a389 ("ptrace: do not audit capability check when outputing /proc/pid/stat")
Signed-off-by: Mickaël Salaün <mic@linux.microsoft.com>
Reviewed-by: Jann Horn <jannh@google.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20201030123849.770769-2-mic@digikod.net
2020-11-17 12:53:22 -08:00
Linus Torvalds 9dacf44c38 Merge branch 'urgent-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu
Pull RCU fix from Paul McKenney:
 "A single commit that fixes a bug that was introduced a couple of merge
  windows ago, but which rather more recently converged to an
  agreed-upon fix. The bug is that interrupts can be incorrectly enabled
  while holding an irq-disabled spinlock. This can of course result in
  self-deadlocks.

  The bug is a bit difficult to trigger. It requires that a preempted
  task be blocking a preemptible-RCU grace period long enough to trigger
  an RCU CPU stall warning. In addition, an interrupt must occur at just
  the right time, and that interrupt's handler must acquire that same
  irq-disabled spinlock. Still, a deadlock is a deadlock.

  Furthermore, we do now have a fix, and that fix survives kernel test
  robot, -next, and rcutorture testing. It has also been verified by
  Sebastian as fixing the bug. Therefore..."

* 'urgent-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu:
  rcu: Don't invoke try_invoke_on_locked_down_task() with irqs disabled
2020-11-17 10:31:56 -08:00
Boqun Feng 43be4388e9 lockdep: Put graph lock/unlock under lock_recursion protection
A warning was hit when running xfstests/generic/068 in a Hyper-V guest:

[...] ------------[ cut here ]------------
[...] DEBUG_LOCKS_WARN_ON(lockdep_hardirqs_enabled())
[...] WARNING: CPU: 2 PID: 1350 at kernel/locking/lockdep.c:5280 check_flags.part.0+0x165/0x170
[...] ...
[...] Workqueue: events pwq_unbound_release_workfn
[...] RIP: 0010:check_flags.part.0+0x165/0x170
[...] ...
[...] Call Trace:
[...]  lock_is_held_type+0x72/0x150
[...]  ? lock_acquire+0x16e/0x4a0
[...]  rcu_read_lock_sched_held+0x3f/0x80
[...]  __send_ipi_one+0x14d/0x1b0
[...]  hv_send_ipi+0x12/0x30
[...]  __pv_queued_spin_unlock_slowpath+0xd1/0x110
[...]  __raw_callee_save___pv_queued_spin_unlock_slowpath+0x11/0x20
[...]  .slowpath+0x9/0xe
[...]  lockdep_unregister_key+0x128/0x180
[...]  pwq_unbound_release_workfn+0xbb/0xf0
[...]  process_one_work+0x227/0x5c0
[...]  worker_thread+0x55/0x3c0
[...]  ? process_one_work+0x5c0/0x5c0
[...]  kthread+0x153/0x170
[...]  ? __kthread_bind_mask+0x60/0x60
[...]  ret_from_fork+0x1f/0x30

The cause of the problem is we have call chain lockdep_unregister_key()
-> <irq disabled by raw_local_irq_save()> lockdep_unlock() ->
arch_spin_unlock() -> __pv_queued_spin_unlock_slowpath() -> pv_kick() ->
__send_ipi_one() -> trace_hyperv_send_ipi_one().

Although this particular warning is triggered because Hyper-V has a
trace point in ipi sending, but in general arch_spin_unlock() may call
another function having a trace point in it, so put the arch_spin_lock()
and arch_spin_unlock() after lock_recursion protection to fix this
problem and avoid similiar problems.

Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20201113110512.1056501-1-boqun.feng@gmail.com
2020-11-17 13:15:35 +01:00
Juri Lelli 2279f540ea sched/deadline: Fix priority inheritance with multiple scheduling classes
Glenn reported that "an application [he developed produces] a BUG in
deadline.c when a SCHED_DEADLINE task contends with CFS tasks on nested
PTHREAD_PRIO_INHERIT mutexes.  I believe the bug is triggered when a CFS
task that was boosted by a SCHED_DEADLINE task boosts another CFS task
(nested priority inheritance).

 ------------[ cut here ]------------
 kernel BUG at kernel/sched/deadline.c:1462!
 invalid opcode: 0000 [#1] PREEMPT SMP
 CPU: 12 PID: 19171 Comm: dl_boost_bug Tainted: ...
 Hardware name: ...
 RIP: 0010:enqueue_task_dl+0x335/0x910
 Code: ...
 RSP: 0018:ffffc9000c2bbc68 EFLAGS: 00010002
 RAX: 0000000000000009 RBX: ffff888c0af94c00 RCX: ffffffff81e12500
 RDX: 000000000000002e RSI: ffff888c0af94c00 RDI: ffff888c10b22600
 RBP: ffffc9000c2bbd08 R08: 0000000000000009 R09: 0000000000000078
 R10: ffffffff81e12440 R11: ffffffff81e1236c R12: ffff888bc8932600
 R13: ffff888c0af94eb8 R14: ffff888c10b22600 R15: ffff888bc8932600
 FS:  00007fa58ac55700(0000) GS:ffff888c10b00000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 00007fa58b523230 CR3: 0000000bf44ab003 CR4: 00000000007606e0
 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
 PKRU: 55555554
 Call Trace:
  ? intel_pstate_update_util_hwp+0x13/0x170
  rt_mutex_setprio+0x1cc/0x4b0
  task_blocks_on_rt_mutex+0x225/0x260
  rt_spin_lock_slowlock_locked+0xab/0x2d0
  rt_spin_lock_slowlock+0x50/0x80
  hrtimer_grab_expiry_lock+0x20/0x30
  hrtimer_cancel+0x13/0x30
  do_nanosleep+0xa0/0x150
  hrtimer_nanosleep+0xe1/0x230
  ? __hrtimer_init_sleeper+0x60/0x60
  __x64_sys_nanosleep+0x8d/0xa0
  do_syscall_64+0x4a/0x100
  entry_SYSCALL_64_after_hwframe+0x49/0xbe
 RIP: 0033:0x7fa58b52330d
 ...
 ---[ end trace 0000000000000002 ]—

He also provided a simple reproducer creating the situation below:

 So the execution order of locking steps are the following
 (N1 and N2 are non-deadline tasks. D1 is a deadline task. M1 and M2
 are mutexes that are enabled * with priority inheritance.)

 Time moves forward as this timeline goes down:

 N1              N2               D1
 |               |                |
 |               |                |
 Lock(M1)        |                |
 |               |                |
 |             Lock(M2)           |
 |               |                |
 |               |              Lock(M2)
 |               |                |
 |             Lock(M1)           |
 |             (!!bug triggered!) |

Daniel reported a similar situation as well, by just letting ksoftirqd
run with DEADLINE (and eventually block on a mutex).

Problem is that boosted entities (Priority Inheritance) use static
DEADLINE parameters of the top priority waiter. However, there might be
cases where top waiter could be a non-DEADLINE entity that is currently
boosted by a DEADLINE entity from a different lock chain (i.e., nested
priority chains involving entities of non-DEADLINE classes). In this
case, top waiter static DEADLINE parameters could be null (initialized
to 0 at fork()) and replenish_dl_entity() would hit a BUG().

Fix this by keeping track of the original donor and using its parameters
when a task is boosted.

Reported-by: Glenn Elliott <glenn@aurora.tech>
Reported-by: Daniel Bristot de Oliveira <bristot@redhat.com>
Signed-off-by: Juri Lelli <juri.lelli@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Daniel Bristot de Oliveira <bristot@redhat.com>
Link: https://lkml.kernel.org/r/20201117061432.517340-1-juri.lelli@redhat.com
2020-11-17 13:15:28 +01:00
Peter Zijlstra ec618b84f6 sched: Fix rq->nr_iowait ordering
schedule()				ttwu()
    deactivate_task();			  if (p->on_rq && ...) // false
					    atomic_dec(&task_rq(p)->nr_iowait);
    if (prev->in_iowait)
      atomic_inc(&rq->nr_iowait);

Allows nr_iowait to be decremented before it gets incremented,
resulting in more dodgy IO-wait numbers than usual.

Note that because we can now do ttwu_queue_wakelist() before
p->on_cpu==0, we lose the natural ordering and have to further delay
the decrement.

Fixes: c6e7bd7afa ("sched/core: Optimize ttwu() spinning on p->on_cpu")
Reported-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Link: https://lkml.kernel.org/r/20201117093829.GD3121429@hirez.programming.kicks-ass.net
2020-11-17 13:15:28 +01:00
Quentin Perret 8e1ac4299a sched/fair: Fix overutilized update in enqueue_task_fair()
enqueue_task_fair() attempts to skip the overutilized update for new
tasks as their util_avg is not accurate yet. However, the flag we check
to do so is overwritten earlier on in the function, which makes the
condition pretty much a nop.

Fix this by saving the flag early on.

Fixes: 2802bf3cd9 ("sched/fair: Add over-utilization/tipping point indicator")
Reported-by: Rick Yiu <rickyiu@google.com>
Signed-off-by: Quentin Perret <qperret@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Link: https://lkml.kernel.org/r/20201112111201.2081902-1-qperret@google.com
2020-11-17 13:15:27 +01:00
Linus Torvalds 64b609d6a6 A set of fixes for perf:
- A set of commits which reduce the stack usage of various perf event
    handling functions which allocated large data structs on stack causing
    stack overflows in the worst case.
 
  - Use the proper mechanism for detecting soft interrupts in the recursion
    protection.
 
  - Make the resursion protection simpler and more robust.
 
  - Simplify the scheduling of event groups to make the code more robust and
    prepare for fixing the issues vs. scheduling of exclusive event groups.
 
  - Prevent event multiplexing and rotation for exclusive event groups
 
  - Correct the perf event attribute exclusive semantics to take pinned
    events, e.g. the PMU watchdog, into account
 
  - Make the anythread filtering conditional for Intel's generic PMU
    counters as it is not longer guaranteed to be supported on newer
    CPUs. Check the corresponding CPUID leaf to make sure.
 
  - Fixup a duplicate initialization in an array which was probably cause by
    the usual copy & paste - forgot to edit mishap.
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Merge tag 'perf-urgent-2020-11-15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull perf fixes from Thomas Gleixner:
 "A set of fixes for perf:

    - A set of commits which reduce the stack usage of various perf
      event handling functions which allocated large data structs on
      stack causing stack overflows in the worst case

    - Use the proper mechanism for detecting soft interrupts in the
      recursion protection

    - Make the resursion protection simpler and more robust

    - Simplify the scheduling of event groups to make the code more
      robust and prepare for fixing the issues vs. scheduling of
      exclusive event groups

    - Prevent event multiplexing and rotation for exclusive event groups

    - Correct the perf event attribute exclusive semantics to take
      pinned events, e.g. the PMU watchdog, into account

    - Make the anythread filtering conditional for Intel's generic PMU
      counters as it is not longer guaranteed to be supported on newer
      CPUs. Check the corresponding CPUID leaf to make sure

    - Fixup a duplicate initialization in an array which was probably
      caused by the usual 'copy & paste - forgot to edit' mishap"

* tag 'perf-urgent-2020-11-15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/x86/intel/uncore: Fix Add BW copypasta
  perf/x86/intel: Make anythread filter support conditional
  perf: Tweak perf_event_attr::exclusive semantics
  perf: Fix event multiplexing for exclusive groups
  perf: Simplify group_sched_in()
  perf: Simplify group_sched_out()
  perf/x86: Make dummy_iregs static
  perf/arch: Remove perf_sample_data::regs_user_copy
  perf: Optimize get_recursion_context()
  perf: Fix get_recursion_context()
  perf/x86: Reduce stack usage for x86_pmu::drain_pebs()
  perf: Reduce stack usage of perf_output_begin()
2020-11-15 09:46:36 -08:00
Linus Torvalds d0a37fd57f A set of scheduler fixes:
- Address a load balancer regression by making the load balancer use the
    same logic as the wakeup path to spread tasks in the LLC domain.
 
  - Prefer the CPU on which a task run last over the local CPU in the fast
    wakeup path for asymmetric CPU capacity systems to align with the
    symmetric case. This ensures more locality and prevents massive
    migration overhead on those asymetric systems
 
  - Fix a memory corruption bug in the scheduler debug code caused by
    handing a modified buffer pointer to kfree().
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Merge tag 'sched-urgent-2020-11-15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull scheduler fixes from Thomas Gleixner:
 "A set of scheduler fixes:

   - Address a load balancer regression by making the load balancer use
     the same logic as the wakeup path to spread tasks in the LLC domain

   - Prefer the CPU on which a task run last over the local CPU in the
     fast wakeup path for asymmetric CPU capacity systems to align with
     the symmetric case. This ensures more locality and prevents massive
     migration overhead on those asymetric systems

   - Fix a memory corruption bug in the scheduler debug code caused by
     handing a modified buffer pointer to kfree()"

* tag 'sched-urgent-2020-11-15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/debug: Fix memory corruption caused by multiple small reads of flags
  sched/fair: Prefer prev cpu in asymmetric wakeup path
  sched/fair: Ensure tasks spreading in LLC during LB
2020-11-15 09:39:35 -08:00
Linus Torvalds 259c2fbef8 Two fixes for the locking subsystem:
- Prevent an unconditional interrupt enable in a futex helper function
     which can be called from contexts which expect interrupts to stay
     disabled across the call.
 
   - Don't modify lockdep chain keys in the validation process as that
     causes chain inconsistency.
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Merge tag 'locking-urgent-2020-11-15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull locking fixes from Thomas Gleixner:
 "Two fixes for the locking subsystem:

   - Prevent an unconditional interrupt enable in a futex helper
     function which can be called from contexts which expect interrupts
     to stay disabled across the call

   - Don't modify lockdep chain keys in the validation process as that
     causes chain inconsistency"

* tag 'locking-urgent-2020-11-15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  lockdep: Avoid to modify chain keys in validate_chain()
  futex: Don't enable IRQs unconditionally in put_pi_state()
2020-11-15 09:25:43 -08:00
Christophe Leroy 2f31ad64a9 panic: don't dump stack twice on warn
Before commit 3f388f2863 ("panic: dump registers on panic_on_warn"),
__warn() was calling show_regs() when regs was not NULL, and show_stack()
otherwise.

After that commit, show_stack() is called regardless of whether
show_regs() has been called or not, leading to duplicated Call Trace:

  ------------[ cut here ]------------
  WARNING: CPU: 0 PID: 1 at arch/powerpc/mm/nohash/8xx.c:186 mmu_mark_initmem_nx+0x24/0x94
  CPU: 0 PID: 1 Comm: swapper Not tainted 5.10.0-rc2-s3k-dev-01375-gf46ec0d3ecbd-dirty #4092
  NIP:  c00128b4 LR: c0010228 CTR: 00000000
  REGS: c9023e40 TRAP: 0700   Not tainted  (5.10.0-rc2-s3k-dev-01375-gf46ec0d3ecbd-dirty)
  MSR:  00029032 <EE,ME,IR,DR,RI>  CR: 24000424  XER: 00000000

  GPR00: c0010228 c9023ef8 c2100000 0074c000 ffffffff 00000000 c2151000 c07b3880
  GPR08: ff000900 0074c000 c8000000 c33b53a8 24000822 00000000 c0003a20 00000000
  GPR16: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
  GPR24: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00800000
  NIP [c00128b4] mmu_mark_initmem_nx+0x24/0x94
  LR [c0010228] free_initmem+0x20/0x58
  Call Trace:
    free_initmem+0x20/0x58
    kernel_init+0x1c/0x114
    ret_from_kernel_thread+0x14/0x1c
  Instruction dump:
  7d291850 7d234b78 4e800020 9421ffe0 7c0802a6 bfc10018 3fe0c060 3bff0000
  3fff4080 3bffffff 90010024 57ff0010 <0fe00000> 392001cd 7c3e0b78 953e0008
  CPU: 0 PID: 1 Comm: swapper Not tainted 5.10.0-rc2-s3k-dev-01375-gf46ec0d3ecbd-dirty #4092
  Call Trace:
    __warn+0x8c/0xd8 (unreliable)
    report_bug+0x11c/0x154
    program_check_exception+0x1dc/0x6e0
    ret_from_except_full+0x0/0x4
  --- interrupt: 700 at mmu_mark_initmem_nx+0x24/0x94
      LR = free_initmem+0x20/0x58
    free_initmem+0x20/0x58
    kernel_init+0x1c/0x114
    ret_from_kernel_thread+0x14/0x1c
  ---[ end trace 31702cd2a9570752 ]---

Only call show_stack() when regs is NULL.

Fixes: 3f388f2863 ("panic: dump registers on panic_on_warn")
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexey Kardashevskiy <aik@ozlabs.ru>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Link: https://lkml.kernel.org/r/e8c055458b080707f1bc1a98ff8bea79d0cec445.1604748361.git.christophe.leroy@csgroup.eu
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-11-14 11:26:04 -08:00
Santosh Sivaraj e7e046155a kernel/watchdog: fix watchdog_allowed_mask not used warning
Define watchdog_allowed_mask only when SOFTLOCKUP_DETECTOR is enabled.

Fixes: 7feeb9cd4f ("watchdog/sysctl: Clean up sysctl variable name space")
Signed-off-by: Santosh Sivaraj <santosh@fossix.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20201106015025.1281561-1-santosh@fossix.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-11-14 11:26:03 -08:00
Matteo Croce df5b0ab3e0 reboot: fix overflow parsing reboot cpu number
Limit the CPU number to num_possible_cpus(), because setting it to a
value lower than INT_MAX but higher than NR_CPUS produces the following
error on reboot and shutdown:

    BUG: unable to handle page fault for address: ffffffff90ab1bb0
    #PF: supervisor read access in kernel mode
    #PF: error_code(0x0000) - not-present page
    PGD 1c09067 P4D 1c09067 PUD 1c0a063 PMD 0
    Oops: 0000 [#1] SMP
    CPU: 1 PID: 1 Comm: systemd-shutdow Not tainted 5.9.0-rc8-kvm #110
    Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-2.fc32 04/01/2014
    RIP: 0010:migrate_to_reboot_cpu+0xe/0x60
    Code: ea ea 00 48 89 fa 48 c7 c7 30 57 f1 81 e9 fa ef ff ff 66 2e 0f 1f 84 00 00 00 00 00 53 8b 1d d5 ea ea 00 e8 14 33 fe ff 89 da <48> 0f a3 15 ea fc bd 00 48 89 d0 73 29 89 c2 c1 e8 06 65 48 8b 3c
    RSP: 0018:ffffc90000013e08 EFLAGS: 00010246
    RAX: ffff88801f0a0000 RBX: 0000000077359400 RCX: 0000000000000000
    RDX: 0000000077359400 RSI: 0000000000000002 RDI: ffffffff81c199e0
    RBP: ffffffff81c1e3c0 R08: ffff88801f41f000 R09: ffffffff81c1e348
    R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
    R13: 00007f32bedf8830 R14: 00000000fee1dead R15: 0000000000000000
    FS:  00007f32bedf8980(0000) GS:ffff88801f480000(0000) knlGS:0000000000000000
    CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
    CR2: ffffffff90ab1bb0 CR3: 000000001d057000 CR4: 00000000000006a0
    DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
    DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
    Call Trace:
      __do_sys_reboot.cold+0x34/0x5b
      do_syscall_64+0x2d/0x40

Fixes: 1b3a5d02ee ("reboot: move arch/x86 reboot= handling to generic kernel")
Signed-off-by: Matteo Croce <mcroce@microsoft.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Fabian Frederick <fabf@skynet.be>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Kees Cook <keescook@chromium.org>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Robin Holt <robinmholt@gmail.com>
Cc: <stable@vger.kernel.org>
Link: https://lkml.kernel.org/r/20201103214025.116799-3-mcroce@linux.microsoft.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-11-14 11:26:03 -08:00
Matteo Croce 8b92c4ff44 Revert "kernel/reboot.c: convert simple_strtoul to kstrtoint"
Patch series "fix parsing of reboot= cmdline", v3.

The parsing of the reboot= cmdline has two major errors:

 - a missing bound check can crash the system on reboot

 - parsing of the cpu number only works if specified last

Fix both.

This patch (of 2):

This reverts commit 616feab753.

kstrtoint() and simple_strtoul() have a subtle difference which makes
them non interchangeable: if a non digit character is found amid the
parsing, the former will return an error, while the latter will just
stop parsing, e.g.  simple_strtoul("123xyx") = 123.

The kernel cmdline reboot= argument allows to specify the CPU used for
rebooting, with the syntax `s####` among the other flags, e.g.
"reboot=warm,s31,force", so if this flag is not the last given, it's
silently ignored as well as the subsequent ones.

Fixes: 616feab753 ("kernel/reboot.c: convert simple_strtoul to kstrtoint")
Signed-off-by: Matteo Croce <mcroce@microsoft.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Robin Holt <robinmholt@gmail.com>
Cc: Fabian Frederick <fabf@skynet.be>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: <stable@vger.kernel.org>
Link: https://lkml.kernel.org/r/20201103214025.116799-2-mcroce@linux.microsoft.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-11-14 11:26:03 -08:00
Dmitrii Banshchikov f782e2c300 bpf: Relax return code check for subprograms
Currently verifier enforces return code checks for subprograms in the
same manner as it does for program entry points. This prevents returning
arbitrary scalar values from subprograms. Scalar type of returned values
is checked by btf_prepare_func_args() and hence it should be safe to
allow only scalars for now. Relax return code checks for subprograms and
allow any correct scalar values.

Fixes: 51c39bb1d5 (bpf: Introduce function-by-function verification)
Signed-off-by: Dmitrii Banshchikov <me@ubique.spb.ru>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20201113171756.90594-1-me@ubique.spb.ru
2020-11-14 08:17:27 -08:00
Linus Torvalds 88b31f07f3 arm64 fixes for -rc4
- Spectre/Meltdown safelisting for some Qualcomm KRYO cores
 
 - Fix RCU splat when failing to online a CPU due to a feature mismatch
 
 - Fix a recently introduced sparse warning in kexec()
 
 - Fix handling of CPU erratum 1418040 for late CPUs
 
 - Ensure hot-added memory falls within linear-mapped region
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Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull arm64 fixes from Will Deacon:

 - Spectre/Meltdown safelisting for some Qualcomm KRYO cores

 - Fix RCU splat when failing to online a CPU due to a feature mismatch

 - Fix a recently introduced sparse warning in kexec()

 - Fix handling of CPU erratum 1418040 for late CPUs

 - Ensure hot-added memory falls within linear-mapped region

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: cpu_errata: Apply Erratum 845719 to KRYO2XX Silver
  arm64: proton-pack: Add KRYO2XX silver CPUs to spectre-v2 safe-list
  arm64: kpti: Add KRYO2XX gold/silver CPU cores to kpti safelist
  arm64: Add MIDR value for KRYO2XX gold/silver CPU cores
  arm64/mm: Validate hotplug range before creating linear mapping
  arm64: smp: Tell RCU about CPUs that fail to come online
  arm64: psci: Avoid printing in cpu_psci_cpu_die()
  arm64: kexec_file: Fix sparse warning
  arm64: errata: Fix handling of 1418040 with late CPU onlining
2020-11-13 09:23:10 -08:00
Linus Torvalds db7c953555 Networking fixes for 5.10-rc4, including fixes from the bpf subtree.
Current release - regressions:
 
  - arm64: dts: fsl-ls1028a-kontron-sl28: specify in-band mode for ENETC
 
 Current release - bugs in new features:
 
  - mptcp: provide rmem[0] limit offset to fix oops
 
 Previous release - regressions:
 
  - IPv6: Set SIT tunnel hard_header_len to zero to fix path MTU
    calculations
 
  - lan743x: correctly handle chips with internal PHY
 
  - bpf: Don't rely on GCC __attribute__((optimize)) to disable GCSE
 
  - mlx5e: Fix VXLAN port table synchronization after function reload
 
 Previous release - always broken:
 
  - bpf: Zero-fill re-used per-cpu map element
 
  - net: udp: fix out-of-order packets when forwarding with UDP GSO
              fraglists turned on
    - fix UDP header access on Fast/frag0 UDP GRO
    - fix IP header access and skb lookup on Fast/frag0 UDP GRO
 
  - ethtool: netlink: add missing netdev_features_change() call
 
  - net: Update window_clamp if SOCK_RCVBUF is set
 
  - igc: Fix returning wrong statistics
 
  - ch_ktls: fix multiple leaks and corner cases in Chelsio TLS offload
 
  - tunnels: Fix off-by-one in lower MTU bounds for ICMP/ICMPv6 replies
 
  - r8169: disable hw csum for short packets on all chip versions
 
  - vrf: Fix fast path output packet handling with async Netfilter rules
 
 Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Merge tag 'net-5.10-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

Pull networking fixes from Jakub Kicinski:
 "Current release - regressions:

   - arm64: dts: fsl-ls1028a-kontron-sl28: specify in-band mode for
     ENETC

  Current release - bugs in new features:

   - mptcp: provide rmem[0] limit offset to fix oops

  Previous release - regressions:

   - IPv6: Set SIT tunnel hard_header_len to zero to fix path MTU
     calculations

   - lan743x: correctly handle chips with internal PHY

   - bpf: Don't rely on GCC __attribute__((optimize)) to disable GCSE

   - mlx5e: Fix VXLAN port table synchronization after function reload

  Previous release - always broken:

   - bpf: Zero-fill re-used per-cpu map element

   - fix out-of-order UDP packets when forwarding with UDP GSO fraglists
     turned on:
       - fix UDP header access on Fast/frag0 UDP GRO
       - fix IP header access and skb lookup on Fast/frag0 UDP GRO

   - ethtool: netlink: add missing netdev_features_change() call

   - net: Update window_clamp if SOCK_RCVBUF is set

   - igc: Fix returning wrong statistics

   - ch_ktls: fix multiple leaks and corner cases in Chelsio TLS offload

   - tunnels: Fix off-by-one in lower MTU bounds for ICMP/ICMPv6 replies

   - r8169: disable hw csum for short packets on all chip versions

   - vrf: Fix fast path output packet handling with async Netfilter
     rules"

* tag 'net-5.10-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (65 commits)
  lan743x: fix use of uninitialized variable
  net: udp: fix IP header access and skb lookup on Fast/frag0 UDP GRO
  net: udp: fix UDP header access on Fast/frag0 UDP GRO
  devlink: Avoid overwriting port attributes of registered port
  vrf: Fix fast path output packet handling with async Netfilter rules
  cosa: Add missing kfree in error path of cosa_write
  net: switch to the kernel.org patchwork instance
  ch_ktls: stop the txq if reaches threshold
  ch_ktls: tcb update fails sometimes
  ch_ktls/cxgb4: handle partial tag alone SKBs
  ch_ktls: don't free skb before sending FIN
  ch_ktls: packet handling prior to start marker
  ch_ktls: Correction in middle record handling
  ch_ktls: missing handling of header alone
  ch_ktls: Correction in trimmed_len calculation
  cxgb4/ch_ktls: creating skbs causes panic
  ch_ktls: Update cheksum information
  ch_ktls: Correction in finding correct length
  cxgb4/ch_ktls: decrypted bit is not enough
  net/x25: Fix null-ptr-deref in x25_connect
  ...
2020-11-12 14:02:04 -08:00
Linus Torvalds fcfb67918c Power management fixes for 5.10-rc4.
Make the intel_pstate driver behave as expected when it operates in
 the passive mode with HWP enabled and the "powersave" governor on
 top of it.
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Merge tag 'pm-5.10-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull power management fixes from Rafael Wysocki:
 "Make the intel_pstate driver behave as expected when it operates in
  the passive mode with HWP enabled and the 'powersave' governor on top
  of it"

* tag 'pm-5.10-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  cpufreq: intel_pstate: Take CPUFREQ_GOV_STRICT_TARGET into account
  cpufreq: Add strict_target to struct cpufreq_policy
  cpufreq: Introduce CPUFREQ_GOV_STRICT_TARGET
  cpufreq: Introduce governor flags
2020-11-12 11:03:38 -08:00
Linus Torvalds 3d5e28bff7 Merge branch 'stable/for-linus-5.10-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/swiotlb
Pull swiotlb fixes from Konrad Rzeszutek Wilk:
 "Two tiny fixes for issues that make drivers under Xen unhappy under
  certain conditions"

* 'stable/for-linus-5.10-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/swiotlb:
  swiotlb: remove the tbl_dma_addr argument to swiotlb_tbl_map_single
  swiotlb: fix "x86: Don't panic if can not alloc buffer for swiotlb"
2020-11-11 14:15:06 -08:00
Kaixu Xia f16e631333 bpf: Fix unsigned 'datasec_id' compared with zero in check_pseudo_btf_id
The unsigned variable datasec_id is assigned a return value from the call
to check_pseudo_btf_id(), which may return negative error code.

This fixes the following coccicheck warning:

  ./kernel/bpf/verifier.c:9616:5-15: WARNING: Unsigned expression compared with zero: datasec_id > 0

Fixes: eaa6bcb71e ("bpf: Introduce bpf_per_cpu_ptr()")
Reported-by: Tosk Robot <tencent_os_robot@tencent.com>
Signed-off-by: Kaixu Xia <kaixuxia@tencent.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Cc: Hao Luo <haoluo@google.com>
Link: https://lore.kernel.org/bpf/1605071026-25906-1-git-send-email-kaixuxia@tencent.com
2020-11-11 10:50:22 +01:00
Paul E. McKenney c583bcb8f5 rcu: Don't invoke try_invoke_on_locked_down_task() with irqs disabled
The try_invoke_on_locked_down_task() function requires that
interrupts be enabled, but it is called with interrupts disabled from
rcu_print_task_stall(), resulting in an "IRQs not enabled as expected"
diagnostic.  This commit therefore updates rcu_print_task_stall()
to accumulate a list of the first few tasks while holding the current
leaf rcu_node structure's ->lock, then releases that lock and only then
uses try_invoke_on_locked_down_task() to attempt to obtain per-task
detailed information.  Of course, as soon as ->lock is released, the
task might exit, so the get_task_struct() function is used to prevent
the task structure from going away in the meantime.

Link: https://lore.kernel.org/lkml/000000000000903d5805ab908fc4@google.com/
Fixes: 5bef8da66a ("rcu: Add per-task state to RCU CPU stall warnings")
Reported-by: syzbot+cb3b69ae80afd6535b0e@syzkaller.appspotmail.com
Reported-by: syzbot+f04854e1c5c9e913cc27@syzkaller.appspotmail.com
Tested-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-11-10 17:10:38 -08:00
Linus Torvalds eccc876724 Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull core dump fix from Al Viro:
 "Fix for multithreaded coredump playing fast and loose with getting
  registers of secondary threads; if a secondary gets caught in the
  middle of exit(2), the conditition it will be stopped in for dumper to
  examine might be unusual enough for things to go wrong.

  Quite a few architectures are fine with that, but some are not."

* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  don't dump the threads that had been already exiting when zapped.
2020-11-10 10:33:55 -08:00
Colin Ian King 8d4d9c7b43 sched/debug: Fix memory corruption caused by multiple small reads of flags
Reading /proc/sys/kernel/sched_domain/cpu*/domain0/flags mutliple times
with small reads causes oopses with slub corruption issues because the kfree is
free'ing an offset from a previous allocation. Fix this by adding in a new
pointer 'buf' for the allocation and kfree and use the temporary pointer tmp
to handle memory copies of the buf offsets.

Fixes: 5b9f8ff7b3 ("sched/debug: Output SD flag names rather than their values")
Reported-by: Jeff Bastian <jbastian@redhat.com>
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Link: https://lkml.kernel.org/r/20201029151103.373410-1-colin.king@canonical.com
2020-11-10 18:38:49 +01:00
Vincent Guittot b4c9c9f156 sched/fair: Prefer prev cpu in asymmetric wakeup path
During fast wakeup path, scheduler always check whether local or prev
cpus are good candidates for the task before looking for other cpus in
the domain. With commit b7a331615d ("sched/fair: Add asymmetric CPU
capacity wakeup scan") the heterogenous system gains a dedicated path
but doesn't try to reuse prev cpu whenever possible. If the previous
cpu is idle and belong to the LLC domain, we should check it 1st
before looking for another cpu because it stays one of the best
candidate and this also stabilizes task placement on the system.

This change aligns asymmetric path behavior with symmetric one and reduces
cases where the task migrates across all cpus of the sd_asym_cpucapacity
domains at wakeup.

This change does not impact normal EAS mode but only the overloaded case or
when EAS is not used.

- On hikey960 with performance governor (EAS disable)

./perf bench sched pipe -T -l 50000
             mainline           w/ patch
# migrations   999364                  0
ops/sec        149313(+/-0.28%)   182587(+/- 0.40) +22%

- On hikey with performance governor

./perf bench sched pipe -T -l 50000
             mainline           w/ patch
# migrations        0                  0
ops/sec         47721(+/-0.76%)    47899(+/- 0.56) +0.4%

According to test on hikey, the patch doesn't impact symmetric system
compared to current implementation (only tested on arm64)

Also read the uclamped value of task's utilization at most twice instead
instead each time we compare task's utilization with cpu's capacity.

Fixes: b7a331615d ("sched/fair: Add asymmetric CPU capacity wakeup scan")
Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Link: https://lkml.kernel.org/r/20201029161824.26389-1-vincent.guittot@linaro.org
2020-11-10 18:38:48 +01:00
Vincent Guittot 16b0a7a1a0 sched/fair: Ensure tasks spreading in LLC during LB
schbench shows latency increase for 95 percentile above since:
  commit 0b0695f2b3 ("sched/fair: Rework load_balance()")

Align the behavior of the load balancer with the wake up path, which tries
to select an idle CPU which belongs to the LLC for a waking task.

calculate_imbalance() will use nr_running instead of the spare
capacity when CPUs share resources (ie cache) at the domain level. This
will ensure a better spread of tasks on idle CPUs.

Running schbench on a hikey (8cores arm64) shows the problem:

tip/sched/core :
schbench -m 2 -t 4 -s 10000 -c 1000000 -r 10
Latency percentiles (usec)
	50.0th: 33
	75.0th: 45
	90.0th: 51
	95.0th: 4152
	*99.0th: 14288
	99.5th: 14288
	99.9th: 14288
	min=0, max=14276

tip/sched/core + patch :
schbench -m 2 -t 4 -s 10000 -c 1000000 -r 10
Latency percentiles (usec)
	50.0th: 34
	75.0th: 47
	90.0th: 52
	95.0th: 78
	*99.0th: 94
	99.5th: 94
	99.9th: 94
	min=0, max=94

Fixes: 0b0695f2b3 ("sched/fair: Rework load_balance()")
Reported-by: Chris Mason <clm@fb.com>
Suggested-by: Rik van Riel <riel@surriel.com>
Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Rik van Riel <riel@surriel.com>
Tested-by: Rik van Riel <riel@surriel.com>
Link: https://lkml.kernel.org/r/20201102102457.28808-1-vincent.guittot@linaro.org
2020-11-10 18:38:48 +01:00
Boqun Feng d61fc96a37 lockdep: Avoid to modify chain keys in validate_chain()
Chris Wilson reported a problem spotted by check_chain_key(): a chain
key got changed in validate_chain() because we modify the ->read in
validate_chain() to skip checks for dependency adding, and ->read is
taken into calculation for chain key since commit f611e8cf98
("lockdep: Take read/write status in consideration when generate
chainkey").

Fix this by avoiding to modify ->read in validate_chain() based on two
facts: a) since we now support recursive read lock detection, there is
no need to skip checks for dependency adding for recursive readers, b)
since we have a), there is only one case left (nest_lock) where we want
to skip checks in validate_chain(), we simply remove the modification
for ->read and rely on the return value of check_deadlock() to skip the
dependency adding.

Reported-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20201102053743.450459-1-boqun.feng@gmail.com
2020-11-10 18:38:38 +01:00
Rafael J. Wysocki 9a2a9ebc0a cpufreq: Introduce governor flags
A new cpufreq governor flag will be added subsequently, so replace
the bool dynamic_switching fleid in struct cpufreq_governor with a
flags field and introduce CPUFREQ_GOV_DYNAMIC_SWITCHING to set for
the "dynamic switching" governors instead of it.

No intentional functional impact.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2020-11-10 18:31:17 +01:00
Will Deacon 04e613ded8 arm64: smp: Tell RCU about CPUs that fail to come online
Commit ce3d31ad3c ("arm64/smp: Move rcu_cpu_starting() earlier") ensured
that RCU is informed early about incoming CPUs that might end up calling
into printk() before they are online. However, if such a CPU fails the
early CPU feature compatibility checks in check_local_cpu_capabilities(),
then it will be powered off or parked without informing RCU, leading to
an endless stream of stalls:

  | rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
  | rcu:	2-O...: (0 ticks this GP) idle=002/1/0x4000000000000000 softirq=0/0 fqs=2593
  | (detected by 0, t=5252 jiffies, g=9317, q=136)
  | Task dump for CPU 2:
  | task:swapper/2       state:R  running task     stack:    0 pid:    0 ppid:     1 flags:0x00000028
  | Call trace:
  | ret_from_fork+0x0/0x30

Ensure that the dying CPU invokes rcu_report_dead() prior to being powered
off or parked.

Cc: Qian Cai <cai@redhat.com>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Reviewed-by: Paul E. McKenney <paulmck@kernel.org>
Suggested-by: Qian Cai <cai@redhat.com>
Link: https://lore.kernel.org/r/20201105222242.GA8842@willie-the-truck
Link: https://lore.kernel.org/r/20201106103602.9849-3-will@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
2020-11-10 13:11:44 +00:00
Wang Qing abbaa433de bpf: Fix passing zero to PTR_ERR() in bpf_btf_printf_prepare
There is a bug when passing zero to PTR_ERR() and return.
Fix the smatch error.

Fixes: c4d0bfb450 ("bpf: Add bpf_snprintf_btf helper")
Signed-off-by: Wang Qing <wangqing@vivo.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yhs@fb.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/1604735144-686-1-git-send-email-wangqing@vivo.com
2020-11-09 22:37:19 +01:00
Peter Zijlstra 1908dc9117 perf: Tweak perf_event_attr::exclusive semantics
Currently perf_event_attr::exclusive can be used to ensure an
event(group) is the sole group scheduled on the PMU. One consequence
is that when you have a pinned event (say the watchdog) you can no
longer have regular exclusive event(group)s.

Inspired by the fact that !pinned events are considered less strict,
allow !pinned,exclusive events to share the PMU with pinned,!exclusive
events.

Pinned,exclusive is still fully exclusive.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20201029162902.105962225@infradead.org
2020-11-09 18:12:36 +01:00
Peter Zijlstra 2714c3962f perf: Fix event multiplexing for exclusive groups
Commit 9e6302056f ("perf: Use hrtimers for event multiplexing")
placed the hrtimer (re)start call in the wrong place.  Instead of
capturing all scheduling failures, it only considered the PMU failure.

The result is that groups using perf_event_attr::exclusive are no
longer rotated.

Fixes: 9e6302056f ("perf: Use hrtimers for event multiplexing")
Reported-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20201029162902.038667689@infradead.org
2020-11-09 18:12:36 +01:00
Peter Zijlstra 251ff2d493 perf: Simplify group_sched_in()
Collate the error paths. Code duplication only leads to divergence and
extra bugs.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20201029162901.972161394@infradead.org
2020-11-09 18:12:35 +01:00
Peter Zijlstra 8c7855d829 perf: Simplify group_sched_out()
Since event_sched_out() clears cpuctx->exclusive upon removal of an
exclusive event (and only group leaders can be exclusive), there is no
point in group_sched_out() trying to do it too. It is impossible for
cpuctx->exclusive to still be set here.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20201029162901.904060564@infradead.org
2020-11-09 18:12:35 +01:00
Peter Zijlstra 76a4efa809 perf/arch: Remove perf_sample_data::regs_user_copy
struct perf_sample_data lives on-stack, we should be careful about it's
size. Furthermore, the pt_regs copy in there is only because x86_64 is a
trainwreck, solve it differently.

Reported-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Steven Rostedt <rostedt@goodmis.org>
Link: https://lkml.kernel.org/r/20201030151955.258178461@infradead.org
2020-11-09 18:12:34 +01:00
Peter Zijlstra 09da9c8125 perf: Optimize get_recursion_context()
"Look ma, no branches!"

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Link: https://lkml.kernel.org/r/20201030151955.187580298@infradead.org
2020-11-09 18:12:34 +01:00
Peter Zijlstra ce0f17fc93 perf: Fix get_recursion_context()
One should use in_serving_softirq() to detect SoftIRQ context.

Fixes: 96f6d44443 ("perf_counter: avoid recursion")
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20201030151955.120572175@infradead.org
2020-11-09 18:12:34 +01:00
Peter Zijlstra 267fb27352 perf: Reduce stack usage of perf_output_begin()
__perf_output_begin() has an on-stack struct perf_sample_data in the
unlikely case it needs to generate a LOST record. However, every call
to perf_output_begin() must already have a perf_sample_data on-stack.

Reported-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20201030151954.985416146@infradead.org
2020-11-09 18:12:33 +01:00
Dan Carpenter 1e106aa350 futex: Don't enable IRQs unconditionally in put_pi_state()
The exit_pi_state_list() function calls put_pi_state() with IRQs disabled
and is not expecting that IRQs will be enabled inside the function.

Use the _irqsave() variant so that IRQs are restored to the original state
instead of being enabled unconditionally.

Fixes: 153fbd1226 ("futex: Fix more put_pi_state() vs. exit_pi_state_list() races")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20201106085205.GA1159983@mwanda
2020-11-09 14:30:30 +01:00
Eddy Wu b4e00444ca fork: fix copy_process(CLONE_PARENT) race with the exiting ->real_parent
current->group_leader->exit_signal may change during copy_process() if
current->real_parent exits.

Move the assignment inside tasklist_lock to avoid the race.

Signed-off-by: Eddy Wu <eddy_wu@trendmicro.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-11-08 11:18:39 -08:00
Linus Torvalds 100e38914a A single fix for the perf core plugging a memory leak in the address filter
parser.
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Merge tag 'perf-urgent-2020-11-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull perf fix from Thomas Gleixner:
 "A single fix for the perf core plugging a memory leak in the address
  filter parser"

* tag 'perf-urgent-2020-11-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/core: Fix a memory leak in perf_event_parse_addr_filter()
2020-11-08 10:05:10 -08:00
Linus Torvalds aaaaa7ecdc A single fix for the futex code where an intermediate state in the
underlying RT mutex was not handled correctly and triggering a BUG()
 instead of treating it as another variant of retry condition.
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Merge tag 'locking-urgent-2020-11-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull futex fix from Thomas Gleixner:
 "A single fix for the futex code where an intermediate state in the
  underlying RT mutex was not handled correctly and triggering a BUG()
  instead of treating it as another variant of retry condition"

* tag 'locking-urgent-2020-11-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  futex: Handle transient "ownerless" rtmutex state correctly
2020-11-08 09:56:37 -08:00
Linus Torvalds 15a9844458 A set of fixes for interrupt chip drivers:
- Fix the fallout of the IPI as interrupt conversion in Kconfig and the
    BCM2836 interrupt chip driver/
 
  - Fixes for interrupt affinity setting and the handling of hierarchical
    irq domains in the SiFive PLIC driver.
 
  - Make the unmapped event handling in the TI SCI driver work correctly.
 
  - A few minor fixes and cleanups in various chip drivers and Kconfig.
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Merge tag 'irq-urgent-2020-11-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull irq fixes from Thomas Gleixner:
 "A set of fixes for interrupt chip drivers:

   - Fix the fallout of the IPI as interrupt conversion in Kconfig and
     the BCM2836 interrupt chip driver

   - Fixes for interrupt affinity setting and the handling of
     hierarchical irq domains in the SiFive PLIC driver

   - Make the unmapped event handling in the TI SCI driver work
     correctly

   - A few minor fixes and cleanups in various chip drivers and Kconfig"

* tag 'irq-urgent-2020-11-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  dt-bindings: irqchip: ti, sci-inta: Fix diagram indentation for unmapped events
  irqchip/ti-sci-inta: Add support for unmapped event handling
  dt-bindings: irqchip: ti, sci-inta: Update for unmapped event handling
  irqchip/renesas-intc-irqpin: Merge irlm_bit and needs_irlm
  irqchip/sifive-plic: Fix chip_data access within a hierarchy
  irqchip/sifive-plic: Fix broken irq_set_affinity() callback
  irqchip/stm32-exti: Add all LP timer exti direct events support
  irqchip/bcm2836: Fix missing __init annotation
  irqchip/mips: Drop selection of IRQ_DOMAIN_HIERARCHY
  irqchip/mst: Make mst_intc_of_init static
  irqchip/mst: MST_IRQ should depend on ARCH_MEDIATEK or ARCH_MSTARV7
  genirq: Let GENERIC_IRQ_IPI select IRQ_DOMAIN_HIERARCHY
2020-11-08 09:52:57 -08:00
Linus Torvalds 6a8d0d283d A single fix for the generic entry code to correct the wrong assumption
that the lockdep interrupt state needs not to be established before calling
 the RCU check.
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Merge tag 'core-urgent-2020-11-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull entry code fix from Thomas Gleixner:
 "A single fix for the generic entry code to correct the wrong
  assumption that the lockdep interrupt state needs not to be
  established before calling the RCU check"

* tag 'core-urgent-2020-11-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  entry: Fix the incorrect ordering of lockdep and RCU check
2020-11-08 09:51:28 -08:00