Commit Graph

34784 Commits

Author SHA1 Message Date
Petr Mladek
ebb2bdcef8 kthread_worker: document CPU hotplug handling
The kthread worker API is simple.  In short, it allows to create, use, and
destroy workers.  kthread_create_worker_on_cpu() just allows to bind a
newly created worker to a given CPU.

It is up to the API user how to handle CPU hotplug.  They have to decide
how to handle pending work items, prevent queuing new ones, and restore
the functionality when the CPU goes off and on.  There are few catches:

   + The CPU affinity gets lost when it is scheduled on an offline CPU.

   + The worker might not exist when the CPU was off when the user
     created the workers.

A good practice is to implement two CPU hotplug callbacks and
destroy/create the worker when CPU goes down/up.

Mention this in the function description.

[akpm@linux-foundation.org: grammar tweaks]

Link: https://lore.kernel.org/r/20201028073031.4536-1-qiang.zhang@windriver.com
Link: https://lkml.kernel.org/r/20201102101039.19227-1-pmladek@suse.com
Reported-by: Zhang Qiang <Qiang.Zhang@windriver.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-15 12:13:36 -08:00
Rob Clark
f630c7c6f1 kthread: add kthread_work tracepoints
While migrating some code from wq to kthread_worker, I found that I missed
the execute_start/end tracepoints.  So add similar tracepoints for
kthread_work.  And for completeness, queue_work tracepoint (although this
one differs slightly from the matching workqueue tracepoint).

Link: https://lkml.kernel.org/r/20201010180323.126634-1-robdclark@gmail.com
Signed-off-by: Rob Clark <robdclark@chromium.org>
Cc: Rob Clark <robdclark@chromium.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "Peter Zijlstra (Intel)" <peterz@infradead.org>
Cc: Phil Auld <pauld@redhat.com>
Cc: Valentin Schneider <valentin.schneider@arm.com>
Cc: Thara Gopinath <thara.gopinath@linaro.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Vincent Donnefort <vincent.donnefort@arm.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Frederic Weisbecker <frederic@kernel.org>
Cc: Ilias Stamatis <stamatis.iliass@gmail.com>
Cc: Liang Chen <cl@rock-chips.com>
Cc: Ben Dooks <ben.dooks@codethink.co.uk>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: "J. Bruce Fields" <bfields@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-15 12:13:36 -08:00
Linus Torvalds
ec6f5e0e5c A set of x86 and membarrier fixes:
- Correct a few problems in the x86 and the generic membarrier
     implementation. Small corrections for assumptions about visibility
     which have turned out not to be true.
 
   - Make the PAT bits for memory encryption correct vs. 4K and 2M/1G page
     table entries as they are at a different location.
 
   - Fix a concurrency issue in the the local bandwidth readout of resource
     control leading to incorrect values
 
   - Fix the ordering of allocating a vector for an interrupt. The order
     missed to respect the provided cpumask when the first attempt of
     allocating node local in the mask fails. It then tries the node instead
     of trying the full provided mask first. This leads to erroneous error
     messages and breaking the (user) supplied affinity request. Reorder it.
 
   - Make the INT3 padding detection in optprobe work correctly.
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Merge tag 'x86-urgent-2020-12-13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 fixes from Thomas Gleixner:
 "A set of x86 and membarrier fixes:

   - Correct a few problems in the x86 and the generic membarrier
     implementation. Small corrections for assumptions about visibility
     which have turned out not to be true.

   - Make the PAT bits for memory encryption correct vs 4K and 2M/1G
     page table entries as they are at a different location.

   - Fix a concurrency issue in the the local bandwidth readout of
     resource control leading to incorrect values

   - Fix the ordering of allocating a vector for an interrupt. The order
     missed to respect the provided cpumask when the first attempt of
     allocating node local in the mask fails. It then tries the node
     instead of trying the full provided mask first. This leads to
     erroneous error messages and breaking the (user) supplied affinity
     request. Reorder it.

   - Make the INT3 padding detection in optprobe work correctly"

* tag 'x86-urgent-2020-12-13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/kprobes: Fix optprobe to detect INT3 padding correctly
  x86/apic/vector: Fix ordering in vector assignment
  x86/resctrl: Fix incorrect local bandwidth when mba_sc is enabled
  x86/mm/mem_encrypt: Fix definition of PMD_FLAGS_DEC_WP
  membarrier: Execute SYNC_CORE on the calling thread
  membarrier: Explicitly sync remote cores when SYNC_CORE is requested
  membarrier: Add an actual barrier before rseq_preempt()
  x86/membarrier: Get rid of a dubious optimization
2020-12-13 11:31:19 -08:00
Andrii Nakryiko
b7906b70a2 bpf: Fix enum names for bpf_this_cpu_ptr() and bpf_per_cpu_ptr() helpers
Remove bpf_ prefix, which causes these helpers to be reported in verifier
dump as bpf_bpf_this_cpu_ptr() and bpf_bpf_per_cpu_ptr(), respectively. Lets
fix it as long as it is still possible before UAPI freezes on these helpers.

Fixes: eaa6bcb71e ("bpf: Introduce bpf_per_cpu_ptr()")
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-11 14:19:07 -08:00
Arnd Bergmann
6e7b64b9dd elfcore: fix building with clang
kernel/elfcore.c only contains weak symbols, which triggers a bug with
clang in combination with recordmcount:

  Cannot find symbol for section 2: .text.
  kernel/elfcore.o: failed

Move the empty stubs into linux/elfcore.h as inline functions.  As only
two architectures use these, just use the architecture specific Kconfig
symbols to key off the declaration.

Link: https://lkml.kernel.org/r/20201204165742.3815221-2-arnd@kernel.org
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Nathan Chancellor <natechancellor@gmail.com>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Barret Rhoden <brho@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-11 14:02:14 -08:00
Linus Torvalds
4d31058b82 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Pull networking fixes from David Miller:

 1) IPsec compat fixes, from Dmitry Safonov.

 2) Fix memory leak in xfrm_user_policy(). Fix from Yu Kuai.

 3) Fix polling in xsk sockets by using sk_poll_wait() instead of
    datagram_poll() which keys off of sk_wmem_alloc and such which xsk
    sockets do not update. From Xuan Zhuo.

 4) Missing init of rekey_data in cfgh80211, from Sara Sharon.

 5) Fix destroy of timer before init, from Davide Caratti.

 6) Missing CRYPTO_CRC32 selects in ethernet driver Kconfigs, from Arnd
    Bergmann.

 7) Missing error return in rtm_to_fib_config() switch case, from Zhang
    Changzhong.

 8) Fix some src/dest address handling in vrf and add a testcase. From
    Stephen Suryaputra.

 9) Fix multicast handling in Seville switches driven by mscc-ocelot
    driver. From Vladimir Oltean.

10) Fix proto value passed to skb delivery demux in udp, from Xin Long.

11) HW pkt counters not reported correctly in enetc driver, from Claudiu
    Manoil.

12) Fix deadlock in bridge, from Joseph Huang.

13) Missing of_node_pur() in dpaa2 driver, fromn Christophe JAILLET.

14) Fix pid fetching in bpftool when there are a lot of results, from
    Andrii Nakryiko.

15) Fix long timeouts in nft_dynset, from Pablo Neira Ayuso.

16) Various stymmac fixes, from Fugang Duan.

17) Fix null deref in tipc, from Cengiz Can.

18) When mss is biog, coose more resonable rcvq_space in tcp, fromn Eric
    Dumazet.

19) Revert a geneve change that likely isnt necessary, from Jakub
    Kicinski.

20) Avoid premature rx buffer reuse in various Intel driversm from Björn
    Töpel.

21) retain EcT bits during TIS reflection in tcp, from Wei Wang.

22) Fix Tso deferral wrt. cwnd limiting in tcp, from Neal Cardwell.

23) MPLS_OPT_LSE_LABEL attribute is 342 ot 8 bits, from Guillaume Nault

24) Fix propagation of 32-bit signed bounds in bpf verifier and add test
    cases, from Alexei Starovoitov.

* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (81 commits)
  selftests: fix poll error in udpgro.sh
  selftests/bpf: Fix "dubious pointer arithmetic" test
  selftests/bpf: Fix array access with signed variable test
  selftests/bpf: Add test for signed 32-bit bound check bug
  bpf: Fix propagation of 32-bit signed bounds from 64-bit bounds.
  MAINTAINERS: Add entry for Marvell Prestera Ethernet Switch driver
  net: sched: Fix dump of MPLS_OPT_LSE_LABEL attribute in cls_flower
  net/mlx4_en: Handle TX error CQE
  net/mlx4_en: Avoid scheduling restart task if it is already running
  tcp: fix cwnd-limited bug for TSO deferral where we send nothing
  net: flow_offload: Fix memory leak for indirect flow block
  tcp: Retain ECT bits for tos reflection
  ethtool: fix stack overflow in ethnl_parse_bitset()
  e1000e: fix S0ix flow to allow S0i3.2 subset entry
  ice: avoid premature Rx buffer reuse
  ixgbe: avoid premature Rx buffer reuse
  i40e: avoid premature Rx buffer reuse
  igb: avoid transmit queue timeout in xdp path
  igb: use xdp_do_flush
  igb: skb add metasize for xdp
  ...
2020-12-10 15:30:13 -08:00
David S. Miller
d9838b1d39 Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf
Alexei Starovoitov says:

====================
pull-request: bpf 2020-12-10

The following pull-request contains BPF updates for your *net* tree.

We've added 21 non-merge commits during the last 12 day(s) which contain
a total of 21 files changed, 163 insertions(+), 88 deletions(-).

The main changes are:

1) Fix propagation of 32-bit signed bounds from 64-bit bounds, from Alexei.

2) Fix ring_buffer__poll() return value, from Andrii.

3) Fix race in lwt_bpf, from Cong.

4) Fix test_offload, from Toke.

5) Various xsk fixes.

Please consider pulling these changes from:

  git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf.git

Thanks a lot!

Also thanks to reporters, reviewers and testers of commits in this pull-request:

Cong Wang, Hulk Robot, Jakub Kicinski, Jean-Philippe Brucker, John
Fastabend, Magnus Karlsson, Maxim Mikityanskiy, Yonghong Song
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2020-12-10 14:29:30 -08:00
Alexei Starovoitov
b02709587e bpf: Fix propagation of 32-bit signed bounds from 64-bit bounds.
The 64-bit signed bounds should not affect 32-bit signed bounds unless the
verifier knows that upper 32-bits are either all 1s or all 0s. For example the
register with smin_value==1 doesn't mean that s32_min_value is also equal to 1,
since smax_value could be larger than 32-bit subregister can hold.
The verifier refines the smax/s32_max return value from certain helpers in
do_refine_retval_range(). Teach the verifier to recognize that smin/s32_min
value is also bounded. When both smin and smax bounds fit into 32-bit
subregister the verifier can propagate those bounds.

Fixes: 3f50f132d8 ("bpf: Verifier, do explicit ALU32 bounds tracking")
Reported-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2020-12-10 13:02:53 -08:00
Andy Lutomirski
e45cdc71d1 membarrier: Execute SYNC_CORE on the calling thread
membarrier()'s MEMBARRIER_CMD_PRIVATE_EXPEDITED_SYNC_CORE is documented as
syncing the core on all sibling threads but not necessarily the calling
thread.  This behavior is fundamentally buggy and cannot be used safely.

Suppose a user program has two threads.  Thread A is on CPU 0 and thread B
is on CPU 1.  Thread A modifies some text and calls
membarrier(MEMBARRIER_CMD_PRIVATE_EXPEDITED_SYNC_CORE).

Then thread B executes the modified code.  If, at any point after
membarrier() decides which CPUs to target, thread A could be preempted and
replaced by thread B on CPU 0.  This could even happen on exit from the
membarrier() syscall.  If this happens, thread B will end up running on CPU
0 without having synced.

In principle, this could be fixed by arranging for the scheduler to issue
sync_core_before_usermode() whenever switching between two threads in the
same mm if there is any possibility of a concurrent membarrier() call, but
this would have considerable overhead.  Instead, make membarrier() sync the
calling CPU as well.

As an optimization, this avoids an extra smp_mb() in the default
barrier-only mode and an extra rseq preempt on the caller.

Fixes: 70216e18e5 ("membarrier: Provide core serializing command, *_SYNC_CORE")
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/r/250ded637696d490c69bef1877148db86066881c.1607058304.git.luto@kernel.org
2020-12-09 09:37:43 +01:00
Andy Lutomirski
758c9373d8 membarrier: Explicitly sync remote cores when SYNC_CORE is requested
membarrier() does not explicitly sync_core() remote CPUs; instead, it
relies on the assumption that an IPI will result in a core sync.  On x86,
this may be true in practice, but it's not architecturally reliable.  In
particular, the SDM and APM do not appear to guarantee that interrupt
delivery is serializing.  While IRET does serialize, IPI return can
schedule, thereby switching to another task in the same mm that was
sleeping in a syscall.  The new task could then SYSRET back to usermode
without ever executing IRET.

Make this more robust by explicitly calling sync_core_before_usermode()
on remote cores.  (This also helps people who search the kernel tree for
instances of sync_core() and sync_core_before_usermode() -- one might be
surprised that the core membarrier code doesn't currently show up in a
such a search.)

Fixes: 70216e18e5 ("membarrier: Provide core serializing command, *_SYNC_CORE")
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/776b448d5f7bd6b12690707f5ed67bcda7f1d427.1607058304.git.luto@kernel.org
2020-12-09 09:37:43 +01:00
Andy Lutomirski
2ecedd7569 membarrier: Add an actual barrier before rseq_preempt()
It seems that most RSEQ membarrier users will expect any stores done before
the membarrier() syscall to be visible to the target task(s).  While this
is extremely likely to be true in practice, nothing actually guarantees it
by a strict reading of the x86 manuals.  Rather than providing this
guarantee by accident and potentially causing a problem down the road, just
add an explicit barrier.

Fixes: 70216e18e5 ("membarrier: Provide core serializing command, *_SYNC_CORE")
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/d3e7197e034fa4852afcf370ca49c30496e58e40.1607058304.git.luto@kernel.org
2020-12-09 09:37:43 +01:00
Linus Torvalds
cd796ed334 Fix userstacktrace option for instances
While writing an application that requires user stack trace option
 to work in instances, I found that the instance option has a bug
 that makes it a nop. The check for performing the user stack trace
 in an instance, checks the top level options (not the instance options)
 to determine if a user stack trace should be performed or not.
 
 This is not only incorrect, but also confusing for users. It confused
 me for a bit!
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Merge tag 'trace-v5.10-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fix from Steven Rostedt:
 "Fix userstacktrace option for instances

  While writing an application that requires user stack trace option to
  work in instances, I found that the instance option has a bug that
  makes it a nop. The check for performing the user stack trace in an
  instance, checks the top level options (not the instance options) to
  determine if a user stack trace should be performed or not.

  This is not only incorrect, but also confusing for users. It confused
  me for a bit!"

* tag 'trace-v5.10-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Fix userstacktrace option for instances
2020-12-07 11:20:26 -08:00
Linus Torvalds
592d9a0835 A set of updates for the interrupt subsystem:
- Make multiqueue devices which use the managed interrupt affinity
     infrastructure work on PowerPC/Pseries. PowerPC does not use the
     generic infrastructure for setting up PCI/MSI interrupts and the
     multiqueue changes failed to update the legacy PCI/MSI infrastructure.
     Make this work by passing the affinity setup information down to the
     mapping and allocation functions.
 
   - Move Jason Cooper from MAINTAINERS to CREDITS as his mail is bouncing
     and he's not reachable. We hope all is well with him and say thanks
     for his work over the years.
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Merge tag 'irq-urgent-2020-12-06' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull irq fixes from Thomas Gleixner:
 "A set of updates for the interrupt subsystem:

   - Make multiqueue devices which use the managed interrupt affinity
     infrastructure work on PowerPC/Pseries. PowerPC does not use the
     generic infrastructure for setting up PCI/MSI interrupts and the
     multiqueue changes failed to update the legacy PCI/MSI
     infrastructure. Make this work by passing the affinity setup
     information down to the mapping and allocation functions.

   - Move Jason Cooper from MAINTAINERS to CREDITS as his mail is
     bouncing and he's not reachable. We hope all is well with him and
     say thanks for his work over the years"

* tag 'irq-urgent-2020-12-06' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  powerpc/pseries: Pass MSI affinity to irq_create_mapping()
  genirq/irqdomain: Add an irq_create_mapping_affinity() function
  MAINTAINERS: Move Jason Cooper to CREDITS
2020-12-06 11:15:55 -08:00
Linus Torvalds
32f741b02f powerpc fixes for 5.10 #5
Three commits fixing possible missed TLB invalidations for multi-threaded
 processes when CPUs are hotplugged in and out.
 
 A fix for a host crash triggerable by host userspace (qemu) in KVM on Power9.
 
 A fix for a host crash in machine check handling when running HPT guests on a
 HPT host.
 
 One commit fixing potential missed TLB invalidations when using the hash MMU on
 Power9 or later.
 
 A regression fix for machines with CPUs on node 0 but no memory.
 
 Thanks to:
   Aneesh Kumar K.V, Cédric Le Goater, Greg Kurz, Milan Mohanty, Milton Miller,
   Nicholas Piggin, Paul Mackerras, Srikar Dronamraju.
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Merge tag 'powerpc-5.10-5' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Pull powerpc fixes from Michael Ellerman:
 "Some more powerpc fixes for 5.10:

   - Three commits fixing possible missed TLB invalidations for
     multi-threaded processes when CPUs are hotplugged in and out.

   - A fix for a host crash triggerable by host userspace (qemu) in KVM
     on Power9.

   - A fix for a host crash in machine check handling when running HPT
     guests on a HPT host.

   - One commit fixing potential missed TLB invalidations when using the
     hash MMU on Power9 or later.

   - A regression fix for machines with CPUs on node 0 but no memory.

  Thanks to Aneesh Kumar K.V, Cédric Le Goater, Greg Kurz, Milan
  Mohanty, Milton Miller, Nicholas Piggin, Paul Mackerras, and Srikar
  Dronamraju"

* tag 'powerpc-5.10-5' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/64s/powernv: Fix memory corruption when saving SLB entries on MCE
  KVM: PPC: Book3S HV: XIVE: Fix vCPU id sanity check
  powerpc/numa: Fix a regression on memoryless node 0
  powerpc/64s: Trim offlined CPUs from mm_cpumasks
  kernel/cpu: add arch override for clear_tasks_mm_cpumask() mm handling
  powerpc/64s/pseries: Fix hash tlbiel_all_isa300 for guest kernels
  powerpc/64s: Fix hash ISA v3.0 TLBIEL instruction generation
2020-12-05 11:16:21 -08:00
Steven Rostedt (VMware)
bcee527895 tracing: Fix userstacktrace option for instances
When the instances were able to use their own options, the userstacktrace
option was left hardcoded for the top level. This made the instance
userstacktrace option bascially into a nop, and will confuse users that set
it, but nothing happens (I was confused when it happened to me!)

Cc: stable@vger.kernel.org
Fixes: 16270145ce ("tracing: Add trace options for core options to instances")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-12-04 16:36:16 -05:00
Linus Torvalds
ef6900acc8 Tracing fixes for 5.10-rc6
- Use correct timestamp variable for ring buffer write stamp update
  - Fix up before stamp and write stamp when crossing ring buffer sub
    buffers
  - Keep a zero delta in ring buffer in slow path if cmpxchg fails
  - Fix trace_printk static buffer for archs that care
  - Fix ftrace record accounting for ftrace ops with trampolines
  - Fix DYNAMIC_FTRACE_WITH_DIRECT_CALLS dependency
  - Remove WARN_ON in hwlat tracer that triggers on something that is OK
  - Make "my_tramp" trampoline in ftrace direct sample code global
  - Fixes in the bootconfig tool for better alignment management
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Merge tag 'trace-v5.10-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fixes from Steven Rostedt:

 - Use correct timestamp variable for ring buffer write stamp update

 - Fix up before stamp and write stamp when crossing ring buffer sub
   buffers

 - Keep a zero delta in ring buffer in slow path if cmpxchg fails

 - Fix trace_printk static buffer for archs that care

 - Fix ftrace record accounting for ftrace ops with trampolines

 - Fix DYNAMIC_FTRACE_WITH_DIRECT_CALLS dependency

 - Remove WARN_ON in hwlat tracer that triggers on something that is OK

 - Make "my_tramp" trampoline in ftrace direct sample code global

 - Fixes in the bootconfig tool for better alignment management

* tag 'trace-v5.10-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  ring-buffer: Always check to put back before stamp when crossing pages
  ftrace: Fix DYNAMIC_FTRACE_WITH_DIRECT_CALLS dependency
  ftrace: Fix updating FTRACE_FL_TRAMP
  tracing: Fix alignment of static buffer
  tracing: Remove WARN_ON in start_thread()
  samples/ftrace: Mark my_tramp[12]? global
  ring-buffer: Set the right timestamp in the slow path of __rb_reserve_next()
  ring-buffer: Update write stamp with the correct ts
  docs: bootconfig: Update file format on initrd image
  tools/bootconfig: Align the bootconfig applied initrd image size to 4
  tools/bootconfig: Fix to check the write failure correctly
  tools/bootconfig: Fix errno reference after printf()
2020-12-01 15:30:18 -08:00
Steven Rostedt (VMware)
68e10d5ff5 ring-buffer: Always check to put back before stamp when crossing pages
The current ring buffer logic checks to see if the updating of the event
buffer was interrupted, and if it is, it will try to fix up the before stamp
with the write stamp to make them equal again. This logic is flawed, because
if it is not interrupted, the two are guaranteed to be different, as the
current event just updated the before stamp before allocation. This
guarantees that the next event (this one or another interrupting one) will
think it interrupted the time updates of a previous event and inject an
absolute time stamp to compensate.

The correct logic is to always update the timestamps when traversing to a
new sub buffer.

Cc: stable@vger.kernel.org
Fixes: a389d86f7f ("ring-buffer: Have nested events still record running time stamp")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-30 23:21:51 -05:00
Naveen N. Rao
49a962c075 ftrace: Fix DYNAMIC_FTRACE_WITH_DIRECT_CALLS dependency
DYNAMIC_FTRACE_WITH_DIRECT_CALLS should depend on
DYNAMIC_FTRACE_WITH_REGS since we need ftrace_regs_caller().

Link: https://lkml.kernel.org/r/fc4b257ea8689a36f086d2389a9ed989496ca63a.1606412433.git.naveen.n.rao@linux.vnet.ibm.com

Cc: stable@vger.kernel.org
Fixes: 763e34e74b ("ftrace: Add register_ftrace_direct()")
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-30 21:43:08 -05:00
Naveen N. Rao
4c75b0ff4e ftrace: Fix updating FTRACE_FL_TRAMP
On powerpc, kprobe-direct.tc triggered FTRACE_WARN_ON() in
ftrace_get_addr_new() followed by the below message:
  Bad trampoline accounting at: 000000004222522f (wake_up_process+0xc/0x20) (f0000001)

The set of steps leading to this involved:
- modprobe ftrace-direct-too
- enable_probe
- modprobe ftrace-direct
- rmmod ftrace-direct <-- trigger

The problem turned out to be that we were not updating flags in the
ftrace record properly. From the above message about the trampoline
accounting being bad, it can be seen that the ftrace record still has
FTRACE_FL_TRAMP set though ftrace-direct module is going away. This
happens because we are checking if any ftrace_ops has the
FTRACE_FL_TRAMP flag set _before_ updating the filter hash.

The fix for this is to look for any _other_ ftrace_ops that also needs
FTRACE_FL_TRAMP.

Link: https://lkml.kernel.org/r/56c113aa9c3e10c19144a36d9684c7882bf09af5.1606412433.git.naveen.n.rao@linux.vnet.ibm.com

Cc: stable@vger.kernel.org
Fixes: a124692b69 ("ftrace: Enable trampoline when rec count returns back to one")
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-30 21:43:07 -05:00
Minchan Kim
8fa655a3a0 tracing: Fix alignment of static buffer
With 5.9 kernel on ARM64, I found ftrace_dump output was broken but
it had no problem with normal output "cat /sys/kernel/debug/tracing/trace".

With investigation, it seems coping the data into temporal buffer seems to
break the align binary printf expects if the static buffer is not aligned
with 4-byte. IIUC, get_arg in bstr_printf expects that args has already
right align to be decoded and seq_buf_bprintf says ``the arguments are saved
in a 32bit word array that is defined by the format string constraints``.
So if we don't keep the align under copy to temporal buffer, the output
will be broken by shifting some bytes.

This patch fixes it.

Link: https://lkml.kernel.org/r/20201125225654.1618966-1-minchan@kernel.org

Cc: <stable@vger.kernel.org>
Fixes: 8e99cf91b9 ("tracing: Do not allocate buffer in trace_find_next_entry() in atomic")
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-30 21:43:07 -05:00
Vasily Averin
310e3a4b5a tracing: Remove WARN_ON in start_thread()
This patch reverts commit 978defee11 ("tracing: Do a WARN_ON()
 if start_thread() in hwlat is called when thread exists")

.start hook can be legally called several times if according
tracer is stopped

screen window 1
[root@localhost ~]# echo 1 > /sys/kernel/tracing/events/kmem/kfree/enable
[root@localhost ~]# echo 1 > /sys/kernel/tracing/options/pause-on-trace
[root@localhost ~]# less -F /sys/kernel/tracing/trace

screen window 2
[root@localhost ~]# cat /sys/kernel/debug/tracing/tracing_on
0
[root@localhost ~]# echo hwlat >  /sys/kernel/debug/tracing/current_tracer
[root@localhost ~]# echo 1 > /sys/kernel/debug/tracing/tracing_on
[root@localhost ~]# cat /sys/kernel/debug/tracing/tracing_on
0
[root@localhost ~]# echo 2 > /sys/kernel/debug/tracing/tracing_on

triggers warning in dmesg:
WARNING: CPU: 3 PID: 1403 at kernel/trace/trace_hwlat.c:371 hwlat_tracer_start+0xc9/0xd0

Link: https://lkml.kernel.org/r/bd4d3e70-400d-9c82-7b73-a2d695e86b58@virtuozzo.com

Cc: Ingo Molnar <mingo@redhat.com>
Cc: stable@vger.kernel.org
Fixes: 978defee11 ("tracing: Do a WARN_ON() if start_thread() in hwlat is called when thread exists")
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-30 21:43:07 -05:00
Andrea Righi
8785f51a17 ring-buffer: Set the right timestamp in the slow path of __rb_reserve_next()
In the slow path of __rb_reserve_next() a nested event(s) can happen
between evaluating the timestamp delta of the current event and updating
write_stamp via local_cmpxchg(); in this case the delta is not valid
anymore and it should be set to 0 (same timestamp as the interrupting
event), since the event that we are currently processing is not the last
event in the buffer.

Link: https://lkml.kernel.org/r/X8IVJcp1gRE+FJCJ@xps-13-7390

Cc: Ingo Molnar <mingo@redhat.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lwn.net/Articles/831207
Fixes: a389d86f7f ("ring-buffer: Have nested events still record running time stamp")
Signed-off-by: Andrea Righi <andrea.righi@canonical.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-30 15:22:05 -05:00
Steven Rostedt (VMware)
55ea4cf403 ring-buffer: Update write stamp with the correct ts
The write stamp, used to calculate deltas between events, was updated with
the stale "ts" value in the "info" structure, and not with the updated "ts"
variable. This caused the deltas between events to be inaccurate, and when
crossing into a new sub buffer, had time go backwards.

Link: https://lkml.kernel.org/r/20201124223917.795844-1-elavila@google.com

Cc: stable@vger.kernel.org
Fixes: a389d86f7f ("ring-buffer: Have nested events still record running time stamp")
Reported-by: "J. Avila" <elavila@google.com>
Tested-by: Daniel Mentz <danielmentz@google.com>
Tested-by: Will McVicker <willmcvicker@google.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-30 15:21:31 -05:00
Laurent Vivier
bb4c6910c8 genirq/irqdomain: Add an irq_create_mapping_affinity() function
There is currently no way to convey the affinity of an interrupt
via irq_create_mapping(), which creates issues for devices that
expect that affinity to be managed by the kernel.

In order to sort this out, rename irq_create_mapping() to
irq_create_mapping_affinity() with an additional affinity parameter that
can be passed down to irq_domain_alloc_descs().

irq_create_mapping() is re-implemented as a wrapper around
irq_create_mapping_affinity().

No functional change.

Fixes: e75eafb9b0 ("genirq/msi: Switch to new irq spreading infrastructure")
Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Greg Kurz <groug@kaod.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20201126082852.1178497-2-lvivier@redhat.com
2020-11-30 12:21:31 +01:00
Linus Torvalds
f91a3aa6bc Yet two more places which invoke tracing from RCU disabled regions in the
idle path. Similar to the entry path the low level idle functions have to
 be non-instrumentable.
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Merge tag 'locking-urgent-2020-11-29' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull locking fixes from Thomas Gleixner:
 "Two more places which invoke tracing from RCU disabled regions in the
  idle path.

  Similar to the entry path the low level idle functions have to be
  non-instrumentable"

* tag 'locking-urgent-2020-11-29' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  intel_idle: Fix intel_idle() vs tracing
  sched/idle: Fix arch_cpu_idle() vs tracing
2020-11-29 11:19:26 -08:00
Linus Torvalds
43d6ecd97c Urgent printk fix for 5.10
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Merge tag 'printk-for-5.10-rc6-fixup' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux

Pull printk fixes from Petr Mladek:

 - do not lose trailing newline in pr_cont() calls

 - two trivial fixes for a dead store and a config description

* tag 'printk-for-5.10-rc6-fixup' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux:
  printk: finalize records with trailing newlines
  printk: remove unneeded dead-store assignment
  init/Kconfig: Fix CPU number in LOG_CPU_MAX_BUF_SHIFT description
2020-11-27 10:38:36 -08:00
Petr Mladek
739e7116b1 Merge branch 'for-5.10-pr_cont-fixup' into for-linus 2020-11-27 13:41:23 +01:00
John Ogness
4ad9921af4 printk: finalize records with trailing newlines
Any record with a trailing newline (LOG_NEWLINE flag) cannot
be continued because the newline has been stripped and will
not be visible if the message is appended. This was already
handled correctly when committing in log_output() but was
not handled correctly when committing in log_store().

Fixes: f5f022e53b ("printk: reimplement log_cont using record extension")
Link: https://lore.kernel.org/r/20201126114836.14750-1-john.ogness@linutronix.de
Reported-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Tested-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
2020-11-27 11:58:54 +01:00
Nicholas Piggin
8ff00399b1 kernel/cpu: add arch override for clear_tasks_mm_cpumask() mm handling
powerpc/64s keeps a counter in the mm which counts bits set in
mm_cpumask as well as other things. This means it can't use generic code
to clear bits out of the mask and doesn't adjust the arch specific
counter.

Add an arch override that allows powerpc/64s to use
clear_tasks_mm_cpumask().

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201126102530.691335-4-npiggin@gmail.com
2020-11-27 00:10:39 +11:00
Peter Zijlstra
58c644ba51 sched/idle: Fix arch_cpu_idle() vs tracing
We call arch_cpu_idle() with RCU disabled, but then use
local_irq_{en,dis}able(), which invokes tracing, which relies on RCU.

Switch all arch_cpu_idle() implementations to use
raw_local_irq_{en,dis}able() and carefully manage the
lockdep,rcu,tracing state like we do in entry.

(XXX: we really should change arch_cpu_idle() to not return with
interrupts enabled)

Reported-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lkml.kernel.org/r/20201120114925.594122626@infradead.org
2020-11-24 16:47:35 +01:00
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