Allow the per-CPU min heap storage to have sufficient space for per-cgroup
iterators.
Based-on-work-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ian Rogers <irogers@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lkml.kernel.org/r/20200214075133.181299-6-irogers@google.com

The storage required for visit_groups_merge's min heap needs to vary in
order to support more iterators, such as when multiple nested cgroups'
events are being visited. This change allows for 2 iterators and doesn't
support growth.
Based-on-work-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ian Rogers <irogers@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lkml.kernel.org/r/20200214075133.181299-5-irogers@google.com

visit_groups_merge will pick the next event based on when it was
inserted in to the context (perf_event group_index). Events may be per CPU
or for any CPU, but in the future we'd also like to have per cgroup events
to avoid searching all events for the events to schedule for a cgroup.
Introduce a min heap for the events that maintains a property that the
earliest inserted event is always at the 0th element. Initialize the heap
with per-CPU and any-CPU events for the context.
Based-on-work-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ian Rogers <irogers@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lkml.kernel.org/r/20200214075133.181299-4-irogers@google.com

Supports push, pop and converting an array into a heap. If the sense of
the compare function is inverted then it can provide a max-heap.
Based-on-work-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ian Rogers <irogers@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lkml.kernel.org/r/20200214075133.181299-3-irogers@google.com

Move perf_cgroup_connect() after perf_event_alloc(), such that we can
find/use the PMU's cpu context.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ian Rogers <irogers@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lkml.kernel.org/r/20200214075133.181299-2-irogers@google.com

We can deduce the ctx and cpuctx from the event, no need to pass them
along. Remove the structure and pass in can_add_hw directly.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

Less is more; unify the two very nearly identical function.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

Signed-off-by: Ingo Molnar <mingo@kernel.org>

Merge tag 'perf-urgent-for-mingo-5.6-20200303' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/urgent

Pull perf/urgent fixes from Arnaldo Carvalho de Melo:

perf symbols:

  Arnaldo Carvalho de Melo:

  - Don't try to find a vmlinux file when looking for kernel modules,
    fixing symbol resolution in systems with compressed kernel modules.

perf env:

  Arnaldo Carvalho de Melo:

  - Do not return pointers to local variables, fixing valid warning from
    gcc 10 for corner case that stops the build due to -Werror.

perf tests:

  Arnaldo Carvalho de Melo:

  - Make global variable static in the bp_account entry to fix build
    with gcc 10.

perf parse-events:

  Arnaldo Carvalho de Melo:

  - Use asprintf() instead of strncpy() to read tracepoint files, addressing
    compiler warning that stops the build as we use -Werror.

perf bench:

  Arnaldo Carvalho de Melo:

  - Share some global variables to fix build with gcc 10.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

Pull cifs fixes from Steve French:
 "Five small cifs/smb3 fixes, two for stable (one for a reconnect
  problem and the other fixes a use case when renaming an open file)"

* tag '5.6-rc4-smb3-fixes' of git://git.samba.org/sfrench/cifs-2.6:
  cifs: Use #define in cifs_dbg
  cifs: fix rename() by ensuring source handle opened with DELETE bit
  cifs: add missing mount option to /proc/mounts
  cifs: fix potential mismatch of UNC paths
  cifs: don't leak -EAGAIN for stat() during reconnect

The dso->kernel value is now set to everything that is in
machine->kmaps, but that was being used to decide if vmlinux lookup is
needed, which ended up making that lookup be made for kernel modules,
that now have dso->kernel set, leading to these kinds of warnings when
running on a machine with compressed kernel modules, like fedora:31:

  [root@five ~]# perf record -F 10000 -a sleep 2
  [ perf record: Woken up 1 times to write data ]
  lzma: fopen failed on vmlinux: 'No such file or directory'
  lzma: fopen failed on /boot/vmlinux: 'No such file or directory'
  lzma: fopen failed on /boot/vmlinux-5.5.5-200.fc31.x86_64: 'No such file or directory'
  lzma: fopen failed on /usr/lib/debug/boot/vmlinux-5.5.5-200.fc31.x86_64: 'No such file or directory'
  lzma: fopen failed on /lib/modules/5.5.5-200.fc31.x86_64/build/vmlinux: 'No such file or directory'
  lzma: fopen failed on vmlinux: 'No such file or directory'
  lzma: fopen failed on /boot/vmlinux: 'No such file or directory'
  lzma: fopen failed on /boot/vmlinux-5.5.5-200.fc31.x86_64: 'No such file or directory'
  lzma: fopen failed on /usr/lib/debug/boot/vmlinux-5.5.5-200.fc31.x86_64: 'No such file or directory'
  lzma: fopen failed on /lib/modules/5.5.5-200.fc31.x86_64/build/vmlinux: 'No such file or directory'
  lzma: fopen failed on vmlinux: 'No such file or directory'
  lzma: fopen failed on /boot/vmlinux: 'No such file or directory'
  lzma: fopen failed on /boot/vmlinux-5.5.5-200.fc31.x86_64: 'No such file or directory'
  lzma: fopen failed on /usr/lib/debug/boot/vmlinux-5.5.5-200.fc31.x86_64: 'No such file or directory'
  lzma: fopen failed on /lib/modules/5.5.5-200.fc31.x86_64/build/vmlinux: 'No such file or directory'
  lzma: fopen failed on vmlinux: 'No such file or directory'
  lzma: fopen failed on /boot/vmlinux: 'No such file or directory'
  lzma: fopen failed on /boot/vmlinux-5.5.5-200.fc31.x86_64: 'No such file or directory'
  lzma: fopen failed on /usr/lib/debug/boot/vmlinux-5.5.5-200.fc31.x86_64: 'No such file or directory'
  lzma: fopen failed on /lib/modules/5.5.5-200.fc31.x86_64/build/vmlinux: 'No such file or directory'
  lzma: fopen failed on vmlinux: 'No such file or directory'
  lzma: fopen failed on /boot/vmlinux: 'No such file or directory'
  lzma: fopen failed on /boot/vmlinux-5.5.5-200.fc31.x86_64: 'No such file or directory'
  lzma: fopen failed on /usr/lib/debug/boot/vmlinux-5.5.5-200.fc31.x86_64: 'No such file or directory'
  lzma: fopen failed on /lib/modules/5.5.5-200.fc31.x86_64/build/vmlinux: 'No such file or directory'
  [ perf record: Captured and wrote 1.024 MB perf.data (1366 samples) ]
  [root@five ~]#

This happens when collecting the buildid, when we find samples for
kernel modules, fix it by checking if the looked up DSO is a kernel
module by other means.

Fixes: 02213cec ("perf maps: Mark module DSOs with kernel type")
Tested-by: Jiri Olsa <jolsa@redhat.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Kim Phillips <kim.phillips@amd.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Link: http://lore.kernel.org/lkml/20200302191007.GD10335@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Noticed with gcc 10 (fedora rawhide) that those variables were not being
declared as static, so end up with:

  ld: /tmp/build/perf/bench/epoll-wait.o:/git/perf/tools/perf/bench/epoll-wait.c:93: multiple definition of `end'; /tmp/build/perf/bench/futex-hash.o:/git/perf/tools/perf/bench/futex-hash.c:40: first defined here
  ld: /tmp/build/perf/bench/epoll-wait.o:/git/perf/tools/perf/bench/epoll-wait.c:93: multiple definition of `start'; /tmp/build/perf/bench/futex-hash.o:/git/perf/tools/perf/bench/futex-hash.c:40: first defined here
  ld: /tmp/build/perf/bench/epoll-wait.o:/git/perf/tools/perf/bench/epoll-wait.c:93: multiple definition of `runtime'; /tmp/build/perf/bench/futex-hash.o:/git/perf/tools/perf/bench/futex-hash.c:40: first defined here
  ld: /tmp/build/perf/bench/epoll-ctl.o:/git/perf/tools/perf/bench/epoll-ctl.c:38: multiple definition of `end'; /tmp/build/perf/bench/futex-hash.o:/git/perf/tools/perf/bench/futex-hash.c:40: first defined here
  ld: /tmp/build/perf/bench/epoll-ctl.o:/git/perf/tools/perf/bench/epoll-ctl.c:38: multiple definition of `start'; /tmp/build/perf/bench/futex-hash.o:/git/perf/tools/perf/bench/futex-hash.c:40: first defined here
  ld: /tmp/build/perf/bench/epoll-ctl.o:/git/perf/tools/perf/bench/epoll-ctl.c:38: multiple definition of `runtime'; /tmp/build/perf/bench/futex-hash.o:/git/perf/tools/perf/bench/futex-hash.c:40: first defined here
  make[4]: *** [/git/perf/tools/build/Makefile.build:145: /tmp/build/perf/bench/perf-in.o] Error 1

Prefix those with bench__ and add them to bench/bench.h, so that we can
share those on the tools needing to access those variables from signal
handlers.
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lore.kernel.org/lkml/20200303155811.GD13702@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Make the code more compact by using asprintf() instead of malloc()+strncpy() which also uses
less memory and avoids these warnings with gcc 10:

    CC       /tmp/build/perf/util/cloexec.o
  In file included from /usr/include/string.h:495,
                   from util/parse-events.h:12,
                   from util/parse-events.c:18:
  In function ‘strncpy’,
      inlined from ‘tracepoint_id_to_path’ at util/parse-events.c:271:5:
  /usr/include/bits/string_fortified.h:106:10: error: ‘__builtin_strncpy’ offset [275, 511] from the object at ‘sys_dirent’ is out of the bounds of referenced subobject ‘d_name’ with type ‘char[256]’ at offset 19 [-Werror=array-bounds]
    106 |   return __builtin___strncpy_chk (__dest, __src, __len, __bos (__dest));
        |          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  In file included from /usr/include/dirent.h:61,
                   from util/parse-events.c:5:
  util/parse-events.c: In function ‘tracepoint_id_to_path’:
  /usr/include/bits/dirent.h:33:10: note: subobject ‘d_name’ declared here
     33 |     char d_name[256];  /* We must not include limits.h! */
        |          ^~~~~~
  In file included from /usr/include/string.h:495,
                   from util/parse-events.h:12,
                   from util/parse-events.c:18:
  In function ‘strncpy’,
      inlined from ‘tracepoint_id_to_path’ at util/parse-events.c:273:5:
  /usr/include/bits/string_fortified.h:106:10: error: ‘__builtin_strncpy’ offset [275, 511] from the object at ‘evt_dirent’ is out of the bounds of referenced subobject ‘d_name’ with type ‘char[256]’ at offset 19 [-Werror=array-bounds]
    106 |   return __builtin___strncpy_chk (__dest, __src, __len, __bos (__dest));
        |          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  In file included from /usr/include/dirent.h:61,
                   from util/parse-events.c:5:
  util/parse-events.c: In function ‘tracepoint_id_to_path’:
  /usr/include/bits/dirent.h:33:10: note: subobject ‘d_name’ declared here
     33 |     char d_name[256];  /* We must not include limits.h! */
        |          ^~~~~~
    CC       /tmp/build/perf/util/call-path.o

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lore.kernel.org/lkml/20200302145535.GA28183@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

It is possible to return a pointer to a local variable when looking up
the architecture name for the running system and no normalization is
done on that value, i.e. we may end up returning the uts.machine local
variable.

While this doesn't happen on most arches, as normalization takes place,
lets fix this by making that a static variable and optimize it a bit by
not always running uname(), only the first time.

Noticed in fedora rawhide running with:

  [perfbuilder@a5ff49d6e6e4 ~]$ gcc --version
  gcc (GCC) 10.0.1 20200216 (Red Hat 10.0.1-0.8)
Reported-by: Jiri Olsa <jolsa@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

To fix the build with newer gccs, that without this patch exit with:

    LD       /tmp/build/perf/tests/perf-in.o
  ld: /tmp/build/perf/tests/bp_account.o:/git/perf/tools/perf/tests/bp_account.c:22: multiple definition of `the_var'; /tmp/build/perf/tests/bp_signal.o:/git/perf/tools/perf/tests/bp_signal.c:38: first defined here
  make[4]: *** [/git/perf/tools/build/Makefile.build:145: /tmp/build/perf/tests/perf-in.o] Error 1

First noticed in fedora:rawhide/32 with:

  [perfbuilder@a5ff49d6e6e4 ~]$ gcc --version
  gcc (GCC) 10.0.1 20200216 (Red Hat 10.0.1-0.8)
Reported-by: Jiri Olsa <jolsa@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Pull x86 fixes from Ingo Molnar:
 "Misc fixes: a pkeys fix for a bug that triggers with weird BIOS
  settings, and two Xen PV fixes: a paravirt interface fix, and
  pagetable dumping fix"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/mm: Fix dump_pagetables with Xen PV
  x86/ioperm: Add new paravirt function update_io_bitmap()
  x86/pkeys: Manually set X86_FEATURE_OSPKE to preserve existing changes

Pull scheduler fix from Ingo Molnar:
 "Fix a scheduler statistics bug"

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/fair: Fix statistics for find_idlest_group()

Pull perf fixes from Ingo Molnar:
 "No kernel side changes, all tooling fixes plus two tooling cleanups
  that were committed late in the merge window alongside the perf
  annotate fixes, delayed by Arnaldo's European trip"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (23 commits)
  perf annotate: Fix segfault with source toggle
  perf annotate: Align struct annotate_args
  perf annotate: Simplify disasm_line allocation and freeing code
  perf annotate: Remove privsize from symbol__annotate() args
  perf probe: Check return value of strlist__add() for -ENOMEM
  perf config: Document missing config options
  perf annotate: Fix perf config option description
  perf annotate: Prefer cmdline option over default config
  perf annotate: Make perf config effective
  perf config: Introduce perf_config_u8()
  perf annotate: Fix --show-nr-samples for tui/stdio2
  perf annotate: Fix --show-total-period for tui/stdio2
  perf annotate/tui: Re-render title bar after switching back from script browser
  tools headers UAPI: Update tools's copy of kvm.h headers
  tools arch x86: Sync the msr-index.h copy with the kernel sources
  perf arch powerpc: Sync powerpc syscall.tbl with the kernel sources
  perf auxtrace: Add auxtrace_record__read_finish()
  perf arm-spe: Fix endless record after being terminated
  perf cs-etm: Fix endless record after being terminated
  perf intel-bts: Fix endless record after being terminated
  ...

Pull EFI fixes from Ingo Molnar:
 "Three fixes to EFI mixed boot mode, mostly related to x86-64 vmap
  stacks activated years ago, bug-fixed recently for EFI, which had
  knock-on effects of various 1:1 mapping assumptions in mixed mode.

  There's also a READ_ONCE() fix for reading an mmap-ed EFI firmware
  data field only once, out of caution"

* 'efi-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  efi: READ_ONCE rng seed size before munmap
  efi/x86: Handle by-ref arguments covering multiple pages in mixed mode
  efi/x86: Remove support for EFI time and counter services in mixed mode
  efi/x86: Align GUIDs to their size in the mixed mode runtime wrapper

Pull ext4 fixes from Ted Ts'o:
 "Two more bug fixes (including a regression) for 5.6"

* tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
  ext4: potential crash on allocation error in ext4_alloc_flex_bg_array()
  jbd2: fix data races at struct journal_head

Pull KVM fixes from Paolo Bonzini:
 "More bugfixes, including a few remaining "make W=1" issues such as too
  large frame sizes on some configurations.

  On the ARM side, the compiler was messing up shadow stacks between EL1
  and EL2 code, which is easily fixed with __always_inline"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: VMX: check descriptor table exits on instruction emulation
  kvm: x86: Limit the number of "kvm: disabled by bios" messages
  KVM: x86: avoid useless copy of cpufreq policy
  KVM: allow disabling -Werror
  KVM: x86: allow compiling as non-module with W=1
  KVM: Pre-allocate 1 cpumask variable per cpu for both pv tlb and pv ipis
  KVM: Introduce pv check helpers
  KVM: let declaration of kvm_get_running_vcpus match implementation
  KVM: SVM: allocate AVIC data structures based on kvm_amd module parameter
  arm64: Ask the compiler to __always_inline functions used by KVM at HYP
  KVM: arm64: Define our own swab32() to avoid a uapi static inline
  KVM: arm64: Ask the compiler to __always_inline functions used at HYP
  kvm: arm/arm64: Fold VHE entry/exit work into kvm_vcpu_run_vhe()
  KVM: arm/arm64: Fix up includes for trace.h

KVM emulates UMIP on hardware that doesn't support it by setting the
'descriptor table exiting' VM-execution control and performing
instruction emulation. When running nested, this emulation is broken as
KVM refuses to emulate L2 instructions by default.

Correct this regression by allowing the emulation of descriptor table
instructions if L1 hasn't requested 'descriptor table exiting'.

Fixes: 07721fee ("KVM: nVMX: Don't emulate instructions in guest mode")
Reported-by: Jan Kiszka <jan.kiszka@web.de>
Cc: stable@vger.kernel.org
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Jim Mattson <jmattson@google.com>
Signed-off-by: Oliver Upton <oupton@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Pull i2c fixes from Wolfram Sang:
 "I2C has three driver bugfixes for you. We agreed on the Mac regression
  to go in via I2C"

* 'i2c/for-current-fixed' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
  macintosh: therm_windtunnel: fix regression when instantiating devices
  i2c: altera: Fix potential integer overflow
  i2c: jz4780: silence log flood on txabrt

If sbi->s_flex_groups_allocated is zero and the first allocation fails
then this code will crash.  The problem is that "i--" will set "i" to
-1 but when we compare "i >= sbi->s_flex_groups_allocated" then the -1
is type promoted to unsigned and becomes UINT_MAX.  Since UINT_MAX
is more than zero, the condition is true so we call kvfree(new_groups[-1]).
The loop will carry on freeing invalid memory until it crashes.

Fixes: 7c990728 ("ext4: fix potential race between s_flex_groups online resizing and access")
Reviewed-by: Suraj Jitindar Singh <surajjs@amazon.com>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: stable@kernel.org
Link: https://lore.kernel.org/r/20200228092142.7irbc44yaz3by7nb@kili.mountainSigned-off-by: Theodore Ts'o <tytso@mit.edu>

Removing attach_adapter from this driver caused a regression for at
least some machines. Those machines had the sensors described in their
DT, too, so they didn't need manual creation of the sensor devices. The
old code worked, though, because manual creation came first. Creation of
DT devices then failed later and caused error logs, but the sensors
worked nonetheless because of the manually created devices.

When removing attach_adaper, manual creation now comes later and loses
the race. The sensor devices were already registered via DT, yet with
another binding, so the driver could not be bound to it.

This fix refactors the code to remove the race and only manually creates
devices if there are no DT nodes present. Also, the DT binding is updated
to match both, the DT and manually created devices. Because we don't
know which device creation will be used at runtime, the code to start
the kthread is moved to do_probe() which will be called by both methods.

Fixes: 3e7bed52 ("macintosh: therm_windtunnel: drop using attach_adapter")
Link: https://bugzilla.kernel.org/show_bug.cgi?id=201723Reported-by: Erhard Furtner <erhard_f@mailbox.org>
Tested-by: Erhard Furtner <erhard_f@mailbox.org>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Cc: stable@kernel.org # v4.19+

journal_head::b_transaction and journal_head::b_next_transaction could
be accessed concurrently as noticed by KCSAN,

 LTP: starting fsync04
 /dev/zero: Can't open blockdev
 EXT4-fs (loop0): mounting ext3 file system using the ext4 subsystem
 EXT4-fs (loop0): mounted filesystem with ordered data mode. Opts: (null)
 ==================================================================
 BUG: KCSAN: data-race in __jbd2_journal_refile_buffer [jbd2] / jbd2_write_access_granted [jbd2]

 write to 0xffff99f9b1bd0e30 of 8 bytes by task 25721 on cpu 70:
  __jbd2_journal_refile_buffer+0xdd/0x210 [jbd2]
  __jbd2_journal_refile_buffer at fs/jbd2/transaction.c:2569
  jbd2_journal_commit_transaction+0x2d15/0x3f20 [jbd2]
  (inlined by) jbd2_journal_commit_transaction at fs/jbd2/commit.c:1034
  kjournald2+0x13b/0x450 [jbd2]
  kthread+0x1cd/0x1f0
  ret_from_fork+0x27/0x50

 read to 0xffff99f9b1bd0e30 of 8 bytes by task 25724 on cpu 68:
  jbd2_write_access_granted+0x1b2/0x250 [jbd2]
  jbd2_write_access_granted at fs/jbd2/transaction.c:1155
  jbd2_journal_get_write_access+0x2c/0x60 [jbd2]
  __ext4_journal_get_write_access+0x50/0x90 [ext4]
  ext4_mb_mark_diskspace_used+0x158/0x620 [ext4]
  ext4_mb_new_blocks+0x54f/0xca0 [ext4]
  ext4_ind_map_blocks+0xc79/0x1b40 [ext4]
  ext4_map_blocks+0x3b4/0x950 [ext4]
  _ext4_get_block+0xfc/0x270 [ext4]
  ext4_get_block+0x3b/0x50 [ext4]
  __block_write_begin_int+0x22e/0xae0
  __block_write_begin+0x39/0x50
  ext4_write_begin+0x388/0xb50 [ext4]
  generic_perform_write+0x15d/0x290
  ext4_buffered_write_iter+0x11f/0x210 [ext4]
  ext4_file_write_iter+0xce/0x9e0 [ext4]
  new_sync_write+0x29c/0x3b0
  __vfs_write+0x92/0xa0
  vfs_write+0x103/0x260
  ksys_write+0x9d/0x130
  __x64_sys_write+0x4c/0x60
  do_syscall_64+0x91/0xb05
  entry_SYSCALL_64_after_hwframe+0x49/0xbe

 5 locks held by fsync04/25724:
  #0: ffff99f9911093f8 (sb_writers#13){.+.+}, at: vfs_write+0x21c/0x260
  #1: ffff99f9db4c0348 (&sb->s_type->i_mutex_key#15){+.+.}, at: ext4_buffered_write_iter+0x65/0x210 [ext4]
  #2: ffff99f5e7dfcf58 (jbd2_handle){++++}, at: start_this_handle+0x1c1/0x9d0 [jbd2]
  #3: ffff99f9db4c0168 (&ei->i_data_sem){++++}, at: ext4_map_blocks+0x176/0x950 [ext4]
  #4: ffffffff99086b40 (rcu_read_lock){....}, at: jbd2_write_access_granted+0x4e/0x250 [jbd2]
 irq event stamp: 1407125
 hardirqs last  enabled at (1407125): [<ffffffff980da9b7>] __find_get_block+0x107/0x790
 hardirqs last disabled at (1407124): [<ffffffff980da8f9>] __find_get_block+0x49/0x790
 softirqs last  enabled at (1405528): [<ffffffff98a0034c>] __do_softirq+0x34c/0x57c
 softirqs last disabled at (1405521): [<ffffffff97cc67a2>] irq_exit+0xa2/0xc0

 Reported by Kernel Concurrency Sanitizer on:
 CPU: 68 PID: 25724 Comm: fsync04 Tainted: G L 5.6.0-rc2-next-20200221+ #7
 Hardware name: HPE ProLiant DL385 Gen10/ProLiant DL385 Gen10, BIOS A40 07/10/2019

The plain reads are outside of jh->b_state_lock critical section which result
in data races. Fix them by adding pairs of READ|WRITE_ONCE().
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Qian Cai <cai@lca.pw>
Link: https://lore.kernel.org/r/20200222043111.2227-1-cai@lca.pwSigned-off-by: Theodore Ts'o <tytso@mit.edu>

Pull SCSI fixes from James Bottomley:
 "Four small fixes.

  Three are in drivers for fairly obvious bugs. The fourth is a set of
  regressions introduced by the compat_ioctl changes because some of the
  compat updates wrongly replaced .ioctl instead of .compat_ioctl"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  scsi: compat_ioctl: cdrom: Replace .ioctl with .compat_ioctl in four appropriate places
  scsi: zfcp: fix wrong data and display format of SFP+ temperature
  scsi: sd_sbc: Fix sd_zbc_report_zones()
  scsi: libfc: free response frame from GPN_ID

Commit 2ae27137 ("x86: mm: convert dump_pagetables to use
walk_page_range") broke Xen PV guests as the hypervisor reserved hole in
the memory map was not taken into account.

Fix that by starting the kernel range only at GUARD_HOLE_END_ADDR.

Fixes: 2ae27137 ("x86: mm: convert dump_pagetables to use walk_page_range")
Reported-by: Julien Grall <julien@xen.org>
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Julien Grall <julien@xen.org>
Link: https://lkml.kernel.org/r/20200221103851.7855-1-jgross@suse.com

Commit 111e7b15 ("x86/ioperm: Extend IOPL config to control ioperm()
as well") reworked the iopl syscall to use I/O bitmaps.

Unfortunately this broke Xen PV domains using that syscall as there is
currently no I/O bitmap support in PV domains.

Add I/O bitmap support via a new paravirt function update_io_bitmap which
Xen PV domains can use to update their I/O bitmaps via a hypercall.

Fixes: 111e7b15 ("x86/ioperm: Extend IOPL config to control ioperm() as well")
Reported-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Cc: <stable@vger.kernel.org> # 5.5
Link: https://lkml.kernel.org/r/20200218154712.25490-1-jgross@suse.com

Merge tag 'perf-urgent-for-mingo-5.6-20200228' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/urgent

Pull perf/urgent fixes from Arnaldo Carvalho de Melo:

perf annotate:

  Ravi Bangoria:

  - Fix segfault with source toggle.

  - Fix --show-total-period and --show-nr-samples for tui/stdio2.

  - Fix handling of settings in ~/.perfconfig versus the ones passed
    in the command line

  - Re-render title bar after switching back from script browser.

  - Fix options man page, document some missing ones.

perf probe:

  He Zhe:

  - Check return value of strlist__add() for -ENOMEM.

tools UAPI:

  Arnaldo Carvalho de Melo:

  - Sync x86's msr-index.h copy with the kernel sources.

  - Update tools's copy of x86's kvm.h headers.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

Pull PCI fixes from Bjorn Helgaas:

 - Fix build issue on 32-bit ARM with old compilers (Marek Szyprowski)

 - Update MAINTAINERS for recent Cadence driver file move (Lukas
   Bulwahn)

* tag 'pci-v5.6-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci:
  MAINTAINERS: Correct Cadence PCI driver path
  PCI: brcmstb: Fix build on 32bit ARM platforms with older compilers

Pull block fixes from Jens Axboe:

 - Passthrough insertion fix (Ming)

 - Kill off some unused arguments (John)

 - blktrace RCU fix (Jan)

 - Dead fields removal for null_blk (Dongli)

 - NVMe polled IO fix (Bijan)

* tag 'block-5.6-2020-02-28' of git://git.kernel.dk/linux-block:
  nvme-pci: Hold cq_poll_lock while completing CQEs
  blk-mq: Remove some unused function arguments
  null_blk: remove unused fields in 'nullb_cmd'
  blktrace: Protect q->blk_trace with RCU
  blk-mq: insert passthrough request into hctx->dispatch directly

Pull io_uring fixes from Jens Axboe:

 - Fix for a race with IOPOLL used with SQPOLL (Xiaoguang)

 - Only show ->fdinfo if procfs is enabled (Tobias)

 - Fix for a chain with multiple personalities in the SQEs

 - Fix for a missing free of personality idr on exit

 - Removal of the spin-for-work optimization

 - Fix for next work lookup on request completion

 - Fix for non-vec read/write result progation in case of links

 - Fix for a fileset references on switch

 - Fix for a recvmsg/sendmsg 32-bit compatability mode

* tag 'io_uring-5.6-2020-02-28' of git://git.kernel.dk/linux-block:
  io_uring: fix 32-bit compatability with sendmsg/recvmsg
  io_uring: define and set show_fdinfo only if procfs is enabled
  io_uring: drop file set ref put/get on switch
  io_uring: import_single_range() returns 0/-ERROR
  io_uring: pick up link work on submit reference drop
  io-wq: ensure work->task_pid is cleared on init
  io-wq: remove spin-for-work optimization
  io_uring: fix poll_list race for SETUP_IOPOLL|SETUP_SQPOLL
  io_uring: fix personality idr leak
  io_uring: handle multiple personalities in link chains

Pull NVMe fix from Keith.

* 'nvme-5.6-rc4' of git://git.infradead.org/nvme:
  nvme-pci: Hold cq_poll_lock while completing CQEs

Pull ACPI fixes from Rafael Wysocki:
 "Fix a couple of configuration issues in the ACPI watchdog (WDAT)
  driver (Mika Westerberg) and make it possible to disable that driver
  at boot time in case it still does not work as expected (Jean
  Delvare)"

* tag 'acpi-5.6-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  ACPI: watchdog: Set default timeout in probe
  ACPI: watchdog: Fix gas->access_width usage
  ACPICA: Introduce ACPI_ACCESS_BYTE_WIDTH() macro
  ACPI: watchdog: Allow disabling WDAT at boot

Pull power management fixes from Rafael Wysocki:
 "Fix a recent cpufreq initialization regression (Rafael Wysocki),
  revert a devfreq commit that made incompatible changes and broke user
  land on some systems (Orson Zhai), drop a stale reference to a
  document that has gone away recently (Jonathan Neuschäfer), and fix a
  typo in a hibernation code comment (Alexandre Belloni)"

* tag 'pm-5.6-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  cpufreq: Fix policy initialization for internal governor drivers
  Revert "PM / devfreq: Modify the device name as devfreq(X) for sysfs"
  PM / hibernate: fix typo "reserverd_size" -> "reserved_size"
  Documentation: power: Drop reference to interface.rst

Pull zonefs fixes from Damien Le Moal:
 "Two fixes in here:

   - Revert the initial decision to silently ignore IOCB_NOWAIT for
     asynchronous direct IOs to sequential zone files. Instead, return
     an error to the user to signal that the feature is not supported
     (from Christoph)

   - A fix to zonefs Kconfig to select FS_IOMAP to avoid build failures
     if no other file system already selected this option (from
     Johannes)"

* tag 'zonefs-5.6-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/dlemoal/zonefs:
  zonefs: select FS_IOMAP
  zonefs: fix IOCB_NOWAIT handling

Merge tag 'kvmarm-fixes-5.6-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD

KVM/arm fixes for 5.6, take #1

- Fix compilation on 32bit
- Move  VHE guest entry/exit into the VHE-specific entry code
- Make sure all functions called by the non-VHE HYP code is tagged as __always_inline

In older version of systemd(219), at boot time, udevadm is called with :
	/usr/bin/udevadm trigger --type=devices --action=add"

This program generates an echo "add" in /sys/devices/system/cpu/cpu<x>/uevent,
leading to the "kvm: disabled by bios" message in case of your Bios disabled
the virtualization extensions.

On a modern system running up to 256 CPU threads, this pollutes the Kernel logs.

This patch offers to ratelimit this message to avoid any userspace program triggering
this uevent printing this message too often.

This patch is only a workaround but greatly reduce the pollution without
breaking the current behavior of printing a message if some try to instantiate
KVM on a system that doesn't support it.

Note that recent versions of systemd (>239) do not have trigger this behavior.

This patch will be useful at least for some using older systemd with recent Kernels.
Signed-off-by: Erwan Velu <e.velu@criteo.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>