We already were able to ask for callchains for a specific event:

  # trace -e nanosleep --call dwarf --event sched:sched_switch/call-graph=fp/ usleep 1

This would enable tracing just the "nanosleep" syscall, with callchains
at syscall exit and would ask the kernel for frame pointer callchains to
be enabled for the "sched:sched_switch" tracepoint event, its just that
we were not resolving the callchain and printing it in 'perf trace', do
it:

  # trace -e nanosleep --call dwarf --event sched:sched_switch/call-graph=fp/ usleep 1
     0.425 ( 0.013 ms): usleep/6718 nanosleep(rqtp: 0x7ffcc1d16e20) ...
     0.425 (         ): sched:sched_switch:usleep:6718 [120] S ==> swapper/2:0 [120])
                                       __schedule+0xfe200402 ([kernel.kallsyms])
                                       schedule+0xfe200035 ([kernel.kallsyms])
                                       do_nanosleep+0xfe20006f ([kernel.kallsyms])
                                       hrtimer_nanosleep+0xfe2000dc ([kernel.kallsyms])
                                       sys_nanosleep+0xfe20007a ([kernel.kallsyms])
                                       do_syscall_64+0xfe200062 ([kernel.kallsyms])
                                       return_from_SYSCALL_64+0xfe200000 ([kernel.kallsyms])
                                       __nanosleep+0xffff008b8cbe2010 (/usr/lib64/libc-2.22.so)
     0.486 ( 0.073 ms): usleep/6718  ... [continued]: nanosleep()) = 0
                                       __nanosleep+0x10 (/usr/lib64/libc-2.22.so)
                                       usleep+0x34 (/usr/lib64/libc-2.22.so)
                                       main+0x1eb (/usr/bin/usleep)
                                       __libc_start_main+0xf0 (/usr/lib64/libc-2.22.so)
                                       _start+0x29 (/usr/bin/usleep)
  #

Pretty compact, huh? DWARF callchains for raw_syscalls:sys_exit + frame
pointer callchains for a tracepoint, if your hardware supports LBR, go
wild with /call-graph=lbr/, guess the next step is to lift this from
'perf script':

  -F, --fields <str>    comma separated output fields prepend with 'type:'. Valid types: hw,sw,trace,raw.
                        Fields: comm,tid,pid,time,cpu,event,trace,ip,sym,dso,addr,symoff,period,iregs,brstack,brstacksym,flags

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-2e7yiv5hqdm8jywlmfivvx2v@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

The new sanity check introduced by:

  26657848 ("perf/core: Verify we have a single perf_hw_context PMU")

... triggered on the AMD uncore driver.

Uncore PMUs are per node, they cannot have per-task counters. Fix it.
Reported-by: Borislav Petkov <bp@suse.de>
Reported-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: acme@redhat.com
Cc: alexander.shishkin@linux.intel.com
Cc: eranian@google.com
Cc: jolsa@redhat.com
Cc: linux-tip-commits@vger.kernel.org
Cc: vincent.weaver@maine.edu
Link: http://lkml.kernel.org/r/20160404140208.GA3448@twins.programming.kicks-ass.netSigned-off-by: Ingo Molnar <mingo@kernel.org>

At the moment, initialization path is using test_cpu_cap(&boot_cpu_data),
to detect PT, which is just open coding boot_cpu_has(). Use the latter
instead.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Acked-by: Borislav Petkov <bp@suse.de>
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: eranian@google.com
Cc: vince@deater.net
Link: http://lkml.kernel.org/r/1459953307-14372-1-git-send-email-alexander.shishkin@linux.intel.comSigned-off-by: Ingo Molnar <mingo@kernel.org>

The uprobe_xol_ops structures are never modified, so declare them as const.

Done with the help of Coccinelle.
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: kernel-janitors@vger.kernel.org
Link: http://lkml.kernel.org/r/1460200649-32526-1-git-send-email-Julia.Lawall@lip6.frSigned-off-by: Ingo Molnar <mingo@kernel.org>

Merge tag 'perf-core-for-mingo-20160411' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/core

Pull perf/core improvements from Arnaldo Carvalho de Melo:

User visible changes:

- Automagically create a 'bpf-output' event, easing the setup of BPF
  C "scripts" that produce output via the perf ring buffer. Now it is
  just a matter of calling any perf tool, such as 'trace', with a C
  source file that references the __bpf_stdout__ output channel and
  that channel will be created and connected to the script:

  # trace -e nanosleep --event test_bpf_stdout.c usleep 1
    0.013 ( 0.013 ms): usleep/2818 nanosleep(rqtp: 0x7ffcead45f40                                        ) ...
    0.013 (         ): __bpf_stdout__:Raise a BPF event!..)
    0.015 (         ): perf_bpf_probe:func_begin:(ffffffff81112460))
    0.261 (         ): __bpf_stdout__:Raise a BPF event!..)
    0.262 (         ): perf_bpf_probe:func_end:(ffffffff81112460 <- ffffffff81003d92))
    0.264 ( 0.264 ms): usleep/2818  ... [continued]: nanosleep()) = 0
  #

  Further work is needed to reduce the number of lines in a perf bpf C source
  file, this being the part where we greatly reduce the command line setup (Wang Nan)

- 'perf trace' now supports callchains, with 'trace --call-graph dwarf' using
  libunwind, just like 'perf top', to ask the kernel for stack dumps for CFI
  processing. This reduces the overhead by asking just for userspace callchains
  and also only for the syscall exit tracepoint (raw_syscalls:sys_exit)
  (Milian Wolff, Arnaldo Carvalho de Melo)

  Try it with, for instance:

     # perf trace --call dwarf ping 127.0.0.1

  An excerpt of a system wide 'perf trace --call dwarf" session is at:

   https://fedorapeople.org/~acme/perf/perf-trace--call-graph-dwarf--all-cpus.txt

  You may need to bump the number of mmap pages, using -m/--mmap-pages,
  but on a Broadwell machine the defaults allowed system wide tracing to
  work without losing that many records, experiment with just some
  syscalls, like:

    # perf trace --call dwarf -e nanosleep,futex

  All the targets available for 'perf record', 'perf top' (--pid, --tid, --cpu,
  etc) should work. Also --duration may be interesting to try.

  To get filenames from in various syscalls pointer args (open, ettc), add this
  to the mix:

  # perf probe 'vfs_getname=getname_flags:72 pathname=filename:string'

  Making this work is next in line:

     # trace --call dwarf --ev sched:sched_switch/call-graph=fp/ usleep 1

  I.e. honouring per-tracepoint callchains in 'perf trace' in addition to
  in raw_syscalls:sys_exit.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

Merge tag 'perf-core-for-mingo-20160408' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/core

Pull perf/core improvements and fixes from Arnaldo Carvalho de Melo:

User visible changes:

- Beautify more syscall arguments in 'perf trace', using the type column in
  tracepoint /format fields to attach, for instance, a pid_t resolver to the
  thread COMM, also attach a mode_t beautifier in the same fashion
  (Arnaldo Carvalho de Melo)

- Build the syscall table id <-> name resolver using the same .tbl file
  used in the kernel to generate headers, to avoid the delay in getting
  new syscalls supported in the audit-libs external dependency, done so
  far only for x86_64 (Arnaldo Carvalho de Melo)

- Improve the documentation of event specifications (Andi Kleen)

- Process update events in 'perf script', fixing up this use case:

    # perf stat -a -I 1000 -e cycles record | perf script -s script.py

- Shared object symbol adjustment fixes, fixing symbol resolution in
  Android (Wang Nan)

Infrastructure changes:

- Add dedicated unwind addr_space member into thread struct, to allow
  tools to use thread->priv, noticed while working on having callchains
  in 'perf trace' (Jiri Olsa)

Build fixes:

- Fix the build in Ubuntu 12.04 (Arnaldo Carvalho de Melo, Vinson Lee)
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

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

Instead of having "[unknown]" as the name used for unresolved symbols,
use the address in the callchain, in hexadecimal form:

  28.801 ( 0.007 ms): qemu-system-x8/10065 ppoll(ufds: 0x55c98b39e400, nfds: 72, tsp: 0x7fffe4e4fe60, sigsetsize: 8) = 0 Timeout
                                     ppoll+0x91 (/usr/lib64/libc-2.22.so)
                                     [0x337309] (/usr/bin/qemu-system-x86_64)
                                     [0x336ab4] (/usr/bin/qemu-system-x86_64)
                                     main+0x1724 (/usr/bin/qemu-system-x86_64)
                                     __libc_start_main+0xf0 (/usr/lib64/libc-2.22.so)
                                     [0xc59a9] (/usr/bin/qemu-system-x86_64)
  35.265 (14.805 ms): gnome-shell/2287  ... [continued]: poll()) = 1
                                     [0xf6fdd] (/usr/lib64/libc-2.22.so)
                                     g_main_context_iterate.isra.29+0x17c (/usr/lib64/libglib-2.0.so.0.4600.2)
                                     g_main_loop_run+0xc2 (/usr/lib64/libglib-2.0.so.0.4600.2)
                                     meta_run+0x2c (/usr/lib64/libmutter.so.0.0.0)
                                     main+0x3f7 (/usr/bin/gnome-shell)
                                     __libc_start_main+0xf0 (/usr/lib64/libc-2.22.so)
                                     [0x2909] (/usr/bin/gnome-shell)
Suggested-by: Milian Wolff <milian.wolff@kdab.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-fja1ods5vqpg42mdz09xcz3r@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

The fprintf_sym() and fprintf_callchain() methods now allow users to
change the existing behaviour of showing "[unknown]" as the name of
unresolved symbols to instead show "[0x123456]", i.e. its address.

The current patch doesn't change tools to use this facility, the results
from 'perf trace' and 'perf script' cotinue like:

70.109 ( 0.001 ms): qemu-system-x8/10153 poll(ufds: 0x7f2d93ffe870, nfds: 1) = 0 Timeout
                                   [unknown] (/usr/lib64/libc-2.22.so)
                                   [unknown] (/usr/lib64/libspice-server.so.1.10.0)
                                   [unknown] (/usr/lib64/libspice-server.so.1.10.0)
                                   [unknown] (/usr/lib64/libspice-server.so.1.10.0)
                                   start_thread+0xca (/usr/lib64/libpthread-2.22.so)
                                   __clone+0x6d (/usr/lib64/libc-2.22.so)

The next patch will make 'perf trace' use the new formatting.
Suggested-by: Milian Wolff <milian.wolff@kdab.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-fja1ods5vqpg42mdz09xcz3r@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

We don't need the callchains at the syscall enter tracepoint, just when
finishing it at syscall exit, so reduce the overhead by asking for
callchains just at syscall exit.
Suggested-by: Milian Wolff <milian.wolff@kdab.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-fja1ods5vqpg42mdz09xcz3r@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

The rename is for consistency with the parameter name.

Make it public for fine grained control of which evsels should have
callchains enabled, like, for instance, will be done in the next
changesets in 'perf trace', to enable callchains just on the
"raw_syscalls:sys_exit" tracepoint.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-og8vup111rn357g4yagus3ao@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

For fiddling with sample_type fields in all evsels in an evlist.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-dg6yavctt0hzl2tsgfb43qsr@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Instead receive a callchain_param pointer to configure callchain
aspects, not doing so if NULL is passed.

This will allow fine grained control over which evsels in an evlist
gets callchains enabled.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-2mupip6khc92mh5x4nw9to82@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

The kernel parts are not that useful:

  # trace -m 512 -e nanosleep --call dwarf  usleep 1
     0.065 ( 0.065 ms): usleep/18732 nanosleep(rqtp: 0x7ffc4ee4e200) = 0
                                       syscall_slow_exit_work ([kernel.kallsyms])
                                       do_syscall_64 ([kernel.kallsyms])
                                       return_from_SYSCALL_64 ([kernel.kallsyms])
                                       __nanosleep (/usr/lib64/libc-2.22.so)
                                       usleep (/usr/lib64/libc-2.22.so)
                                       main (/usr/bin/usleep)
                                       __libc_start_main (/usr/lib64/libc-2.22.so)
                                       _start (/usr/bin/usleep)
  #

So lets just use perf_event_attr.exclude_callchain_kernel to avoid
collecting it in the ring buffer:

  # trace -m 512 -e nanosleep --call dwarf  usleep 1
     0.063 ( 0.063 ms): usleep/19212 nanosleep(rqtp: 0x7ffc3df10fb0) = 0
                                       __nanosleep (/usr/lib64/libc-2.22.so)
                                       usleep (/usr/lib64/libc-2.22.so)
                                       main (/usr/bin/usleep)
                                       __libc_start_main (/usr/lib64/libc-2.22.so)
                                       _start (/usr/bin/usleep)
  #

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-qctu3gqhpim0dfbcp9d86c91@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

In 'perf trace' we're just interested in printing callchains, and we
don't want to use the symbol_conf.use_callchain, so move the callchain
part to a new method.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-kcn3romzivcpxb3u75s9nz33@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

As it receives a FILE, and its more than just the IP, which can even be
requested not to be printed.

For consistency with other similar methods in tools/perf/, name it as
perf_evsel__fprintf_sym() and make it return the number of bytes
printed, just like 'fprintf(3)'

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-84gawlqa3lhk63nf0t9vnqnn@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Now, one can print the call chain for every encountered sys_exit event,
e.g.:

    $ perf trace -e nanosleep --call-graph dwarf path/to/ex_sleep
    1005.757 (1000.090 ms): ex_sleep/13167 nanosleep(...) = 0
                                             syscall_slow_exit_work ([kernel.kallsyms])
                                             syscall_return_slowpath ([kernel.kallsyms])
                                             int_ret_from_sys_call ([kernel.kallsyms])
                                             __nanosleep (/usr/lib/libc-2.23.so)
                                             [unknown] (/usr/lib/libQt5Core.so.5.6.0)
                                             QThread::sleep (/usr/lib/libQt5Core.so.5.6.0)
                                             main (path/to/ex_sleep)
                                             __libc_start_main (/usr/lib/libc-2.23.so)
                                             _start (path/to/ex_sleep)

Note that it is advised to increase the number of mmap pages to prevent
event losses when using this new feature. Often, adding `-m 10M` to the
`perf trace` invocation is enough.

This feature is also available in strace when built with libunwind via
`strace -k`. Performance wise, this solution is much better:

    $ time find path/to/linux &> /dev/null

    real    0m0.051s
    user    0m0.013s
    sys     0m0.037s

    $ time perf trace -m 800M --call-graph dwarf find path/to/linux &> /dev/null

    real    0m2.624s
    user    0m1.203s
    sys     0m1.333s

    $ time strace -k find path/to/linux  &> /dev/null

    real    0m35.398s
    user    0m10.403s
    sys     0m23.173s

Note that it is currently not possible to configure the print output.
Adding such a feature, similar to what is available in `perf script` via
its `--fields` knob can be added later on.
Signed-off-by: Milian Wolff <milian.wolff@kdab.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
LPU-Reference: 1460115255-17648-1-git-send-email-milian.wolff@kdab.com
[ Split from a larger patch, do not print the IP, left align,
  remove dup call symbol__init(), added man page entry ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

For callchains, etc where we want it to align just below the syscall
name, for instance, in 'perf trace'

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-uk9ekchd67651c625ltaur5y@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

As this function will be used in 'perf trace'.

Cc: Jiri Olsa <jolsa@kernel.org>
Link: http://lkml.kernel.org/n/tip-8x297v9utnxq77onikevvlse@git.kernel.org
[ Split from a larger patch ]
Signed-off-by: Milian Wolff <milian.wolff@kdab.com>

This patch removes the need to set a bpf-output event in cmdline.  By
referencing a map named '__bpf_stdout__', perf automatically creates an
event for it.

For example:

  # perf record -e ./test_bpf_trace.c usleep 100000
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.012 MB perf.data (2 samples) ]
  # perf script
           usleep  4639 [000] 261895.307826:        0            __bpf_stdout__:  ffffffff810eb9a1 ...
       BPF output: 0000: 52 61 69 73 65 20 61 20  Raise a
                   0008: 42 50 46 20 65 76 65 6e  BPF even
                   0010: 74 21 00 00              t!..
       BPF string: "Raise a BPF event!"

           usleep  4639 [000] 261895.407883:        0            __bpf_stdout__:  ffffffff8105d609 ...
       BPF output: 0000: 52 61 69 73 65 20 61 20  Raise a
                   0008: 42 50 46 20 65 76 65 6e  BPF even
                   0010: 74 21 00 00              t!..
       BPF string: "Raise a BPF event!"

  perf record -e ./test_bpf_trace.c usleep 100000

  equals to:

  perf record -e bpf-output/no-inherit=1,name=__bpf_stdout__/ \
              -e ./test_bpf_trace.c/map:__bpf_stdout__.event=__bpf_stdout__/ \
              usleep 100000

Where test_bpf_trace.c is:

  /************************ BEGIN **************************/
  #include <uapi/linux/bpf.h>
  struct bpf_map_def {
         unsigned int type;
         unsigned int key_size;
         unsigned int value_size;
         unsigned int max_entries;
  };
  #define SEC(NAME) __attribute__((section(NAME), used))
  static u64 (*ktime_get_ns)(void) =
         (void *)BPF_FUNC_ktime_get_ns;
  static int (*trace_printk)(const char *fmt, int fmt_size, ...) =
         (void *)BPF_FUNC_trace_printk;
  static int (*get_smp_processor_id)(void) =
         (void *)BPF_FUNC_get_smp_processor_id;
  static int (*perf_event_output)(void *, struct bpf_map_def *, int, void *, unsigned long) =
         (void *)BPF_FUNC_perf_event_output;

  struct bpf_map_def SEC("maps") __bpf_stdout__ = {
         .type = BPF_MAP_TYPE_PERF_EVENT_ARRAY,
         .key_size = sizeof(int),
         .value_size = sizeof(u32),
         .max_entries = __NR_CPUS__,
  };

  static inline int __attribute__((always_inline))
  func(void *ctx, int type)
  {
	char output_str[] = "Raise a BPF event!";
	char err_str[] = "BAD %d\n";
	int err;

        err = perf_event_output(ctx, &__bpf_stdout__, get_smp_processor_id(),
			        &output_str, sizeof(output_str));
	if (err)
		trace_printk(err_str, sizeof(err_str), err);
        return 1;
  }
  SEC("func_begin=sys_nanosleep")
  int func_begin(void *ctx) {return func(ctx, 1);}
  SEC("func_end=sys_nanosleep%return")
  int func_end(void *ctx) { return func(ctx, 2);}
  char _license[] SEC("license") = "GPL";
  int _version SEC("version") = LINUX_VERSION_CODE;
  /************************* END ***************************/

Committer note:

Testing with 'perf trace':

  # trace -e nanosleep --ev test_bpf_stdout.c usleep 1
     0.007 ( 0.007 ms): usleep/729 nanosleep(rqtp: 0x7ffc5bbc5fe0) ...
     0.007 (         ): __bpf_stdout__:Raise a BPF event!..)
     0.008 (         ): perf_bpf_probe:func_begin:(ffffffff81112460))
     0.069 (         ): __bpf_stdout__:Raise a BPF event!..)
     0.070 (         ): perf_bpf_probe:func_end:(ffffffff81112460 <- ffffffff81003d92))
     0.072 ( 0.072 ms): usleep/729  ... [continued]: nanosleep()) = 0
  #
Suggested-and-Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1460128045-97310-5-git-send-email-wangnan0@huawei.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

This patch allows cloning bpf-output event configuration among multiple
bpf scripts. If there exist a map named '__bpf_output__' and not
configured using 'map:__bpf_output__.event=', this patch clones the
configuration of another '__bpf_stdout__' map. For example, following
command:

  # perf trace --ev bpf-output/no-inherit,name=evt/ \
               --ev ./test_bpf_trace.c/map:__bpf_stdout__.event=evt/ \
               --ev ./test_bpf_trace2.c usleep 100000

equals to:

  # perf trace --ev bpf-output/no-inherit,name=evt/ \
               --ev ./test_bpf_trace.c/map:__bpf_stdout__.event=evt/  \
               --ev ./test_bpf_trace2.c/map:__bpf_stdout__.event=evt/ \
               usleep 100000
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Suggested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1460128045-97310-4-git-send-email-wangnan0@huawei.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Pull ARM fixes from Russell King:
 "A couple of small fixes, and wiring up the new syscalls which appeared
  during the merge window"

* 'fixes' of git://ftp.arm.linux.org.uk/~rmk/linux-arm:
  ARM: 8550/1: protect idiv patching against undefined gcc behavior
  ARM: wire up preadv2 and pwritev2 syscalls
  ARM: SMP enable of cache maintanence broadcast

Pull MMC fixes from Ulf Hansson:
 "Here are a couple of mmc fixes intended for v4.6 rc3:

  MMC host:
   - sdhci: Fix regression setting power on Trats2 board
   - sdhci-pci: Add support and PCI IDs for more Broxton host controllers"

* tag 'mmc-v4.6-rc1' of git://git.linaro.org/people/ulf.hansson/mmc:
  mmc: sdhci-pci: Add support and PCI IDs for more Broxton host controllers
  mmc: sdhci: Fix regression setting power on Trats2 board

Pull i2c fixes from Wolfram Sang:
 "Some bugfixes from I2C:

   - fix a uevent triggered boot problem by removing a useless debug
     print

   - fix sysfs-attributes of the new i2c-demux-pinctrl driver to follow
     standard kernel behaviour

   - fix a potential division-by-zero error (needed two takes)"

* 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
  i2c: jz4780: really prevent potential division by zero
  Revert "i2c: jz4780: prevent potential division by zero"
  i2c: jz4780: prevent potential division by zero
  i2c: mux: demux-pinctrl: Update docs to new sysfs-attributes
  i2c: mux: demux-pinctrl: Clean up sysfs attributes
  i2c: prevent endless uevent loop with CONFIG_I2C_DEBUG_CORE

This reverts commit 1028b55b.

It's broken: it makes ext4 return an error at an invalid point, causing
the readdir wrappers to write the the position of the last successful
directory entry into the position field, which means that the next
readdir will now return that last successful entry _again_.

You can only return fatal errors (that terminate the readdir directory
walk) from within the filesystem readdir functions, the "normal" errors
(that happen when the readdir buffer fills up, for example) happen in
the iterorator where we know the position of the actual failing entry.

I do have a very different patch that does the "signal_pending()"
handling inside the iterator function where it is allowable, but while
that one passes all the sanity checks, I screwed up something like four
times while emailing it out, so I'm not going to commit it today.

So my track record is not good enough, and the stars will have to align
better before that one gets committed.  And it would be good to get some
review too, of course, since celestial alignments are always an iffy
debugging model.

IOW, let's just revert the commit that caused the problem for now.
Reported-by: Greg Thelen <gthelen@google.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull parisc fixes from Helge Deller:
 "Since commit 0de79858 ("parisc: Use generic extable search and
  sort routines") module loading is boken on parisc, because the parisc
  module loader wasn't prepared for the new R_PARISC_PCREL32 relocations.

  In addition, due to that breakage, Mikulas Patocka noticed that
  handling exceptions from modules probably never worked on parisc.  It
  was just masked by the fact that exceptions from modules don't happen
  during normal use.

  This patch series fixes those issues and survives the tests of the
  lib/test_user_copy kernel module test.  Some patches are tagged for
  stable"

* 'parisc-4.6-3' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
  parisc: Update comment regarding relative extable support
  parisc: Unbreak handling exceptions from kernel modules
  parisc: Fix kernel crash with reversed copy_from_user()
  parisc: Avoid function pointers for kernel exception routines
  parisc: Handle R_PARISC_PCREL32 relocations in kernel modules

Pull libnvdimm fixes from Dan Williams:
 "Three fixes, the first two are tagged for -stable:

   - The ndctl utility/library gained expanded unit tests illuminating a
     long standing bug in the libnvdimm SMART data retrieval
     implementation.

     It has been broken since its initial implementation, now fixed.

   - Another one line fix for the detection of stale info blocks.

     Without this change userspace can get into a situation where it is
     unable to reconfigure a namespace.

   - Fix the badblock initialization path in the presence of the new (in
     v4.6-rc1) section alignment workarounds.

     Without this change badblocks will be reported at the wrong offset.

  These have received a build success report from the kbuild robot and
  have appeared in -next with no reported issues"

* 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
  libnvdimm, pfn: fix nvdimm_namespace_add_poison() vs section alignment
  libnvdimm, pfn: fix uuid validation
  libnvdimm: fix smart data retrieval

Pull GPIO fixes from Linus Walleij:
 "Here is a set of four GPIO fixes.  The two fixes to the core are
  serious as they are regressing minor architectures.

  Core fixes:

   - Defer GPIO device setup until after gpiolib is initialized.

     It turns out that a few very tightly integrated GPIO platform
     drivers initialize so early (befor core_initcall()) so that the
     gpiolib isn't even initialized itself.  That limits what the
     library can do, and we cannot reference uninitialized fields until
     later.

     Defer some of the initialization until right after the gpiolib is
     initialized in these (rare) cases.

   - As a consequence: do not use devm_* resources when allocating the
     states in the initial set-up of the gpiochip.

  Driver fixes:

   - In ACPI retrieveal: ignore GpioInt when looking for output GPIOs.

   - Fix legacy builds on the PXA without a backing pin controller.

   - Use correct datatype on pca953x register writes"

* tag 'gpio-v4.6-3' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio:
  gpio: pca953x: Use correct u16 value for register word write
  gpiolib: Defer gpio device setup until after gpiolib initialization
  gpiolib: Do not use devm functions when registering gpio chip
  gpio: pxa: fix legacy non pinctrl aware builds
  gpio / ACPI: ignore GpioInt() GPIOs when requesting GPIO_OUT_*

Pull tty fixes from Greg KH:
 "Here are two tty fixes for issues found.

  One was due to a merge error in 4.6-rc1, and the other a regression
  fix for UML consoles that broke in 4.6-rc1.

  Both have been in linux-next for a while"

* tag 'tty-4.6-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
  tty: Fix merge of "tty: Refactor tty_open()"
  tty: Fix UML console breakage

Pull USB fixes from Greg KH:
 "Here are some USB fixes and new device ids for 4.6-rc3.

  Nothing major, the normal USB gadget fixes and usb-serial driver ids,
  along with some other fixes mixed in.  All except the USB serial ids
  have been tested in linux-next, the id additions should be fine as
  they are 'trivial'"

* tag 'usb-4.6-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb: (25 commits)
  USB: option: add "D-Link DWM-221 B1" device id
  USB: serial: cp210x: Adding GE Healthcare Device ID
  USB: serial: ftdi_sio: Add support for ICP DAS I-756xU devices
  usb: dwc3: keystone: drop dma_mask configuration
  usb: gadget: udc-core: remove manual dma configuration
  usb: dwc3: pci: add ID for one more Intel Broxton platform
  usb: renesas_usbhs: fix to avoid using a disabled ep in usbhsg_queue_done()
  usb: dwc2: do not override forced dr_mode in gadget setup
  usb: gadget: f_midi: unlock on error
  USB: digi_acceleport: do sanity checking for the number of ports
  USB: cypress_m8: add endpoint sanity check
  USB: mct_u232: add sanity checking in probe
  usb: fix regression in SuperSpeed endpoint descriptor parsing
  USB: usbip: fix potential out-of-bounds write
  usb: renesas_usbhs: disable TX IRQ before starting TX DMAC transfer
  usb: renesas_usbhs: avoid NULL pointer derefernce in usbhsf_pkt_handler()
  usb: gadget: f_midi: Fixed a bug when buflen was smaller than wMaxPacketSize
  usb: phy: qcom-8x16: fix regulator API abuse
  usb: ch9: Fix SSP Device Cap wFunctionalitySupport type
  usb: gadget: composite: Access SSP Dev Cap fields properly
  ...

Pull staging and IIO driver fixes from Greg KH:
 "Here are some IIO driver fixes, along with two staging driver fixes
  for 4.6-rc3.

  One staging driver patch reverts the deletion of a driver that
  happened in 4.6-rc1.  We thought that laptop.org was dead, but it's
  still alive and kicking, and has users that were mad we broke their
  hardware by deleting a driver for their machines.  So that driver is
  added back and everyone is happy again.

  All of these have been in linux-next for a while with no reported
  issues"

* tag 'staging-4.6-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging:
  Revert "Staging: olpc_dcon: Remove obsolete driver"
  staging/rdma/hfi1: select CRC32
  iio: gyro: bmg160: fix buffer read values
  iio: gyro: bmg160: fix endianness when reading axes
  iio: accel: bmc150: fix endianness when reading axes
  iio: st_magn: always define ST_MAGN_TRIGGER_SET_STATE
  iio: fix config watermark initial value
  iio: health: max30100: correct FIFO check condition
  iio: imu: Fix inv_mpu6050 dependencies
  iio: adc: Fix build error of missing devm_ioremap_resource on UM
  iio: light: apds9960: correct FIFO check condition
  iio: adc: max1363: correct reference voltage
  iio: adc: max1363: add missing adc to max1363_id

Pull SCSI fixes from James Bottomley:
 "This is a set of eight fixes.

  Two are trivial gcc-6 updates (brace additions and unused variable
  removal).  There's a couple of cxlflash regressions, a correction for
  sd being overly chatty on revalidation (causing excess log increases).
  A VPD issue which could crash USB devices because they seem very
  intolerant to VPD inquiries, an ALUA deadlock fix and a mpt3sas buffer
  overrun fix"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  scsi: Do not attach VPD to devices that don't support it
  sd: Fix excessive capacity printing on devices with blocks bigger than 512 bytes
  scsi_dh_alua: Fix a recently introduced deadlock
  scsi: Declare local symbols static
  cxlflash: Move to exponential back-off when cmd_room is not available
  cxlflash: Fix regression issue with re-ordering patch
  mpt3sas: Don't overreach ioc->reply_post[] during initialization
  aacraid: add missing curly braces

Pull MD fixes from Shaohua Li:
 "This update mainly fixes bugs:

   - fix error handling (Guoqing)
   - fix a crash when a disk is hotremoved (me)
   - fix a dead loop (Wei Fang)"

* tag 'md/4.6-rc2-fix' of git://git.kernel.org/pub/scm/linux/kernel/git/shli/md:
  md/bitmap: clear bitmap if bitmap_create failed
  MD: add rdev reference for super write
  md: fix a trivial typo in comments
  md:raid1: fix a dead loop when read from a WriteMostly disk

Pull power management and ACPI fixes from Rafael Wysocki:
 "Fixes for some issues discovered after recent changes and for some
  that have just been found lately regardless of those changes
  (intel_pstate, intel_idle, PM core, mailbox/pcc, turbostat) plus
  support for some new CPU models (intel_idle, Intel RAPL driver,
  turbostat) and documentation updates (intel_pstate, PM core).

  Specifics:

   - intel_pstate fixes for two issues exposed by the recent switch over
     from using timers and for one issue introduced during the 4.4 cycle
     plus new comments describing data structures used by the driver
     (Rafael Wysocki, Srinivas Pandruvada).

   - intel_idle fixes related to CPU offline/online (Richard Cochran).

   - intel_idle support (new CPU IDs and state definitions mostly) for
     Skylake-X and Kabylake processors (Len Brown).

   - PCC mailbox driver fix for an out-of-bounds memory access that may
     cause the kernel to panic() (Shanker Donthineni).

   - New (missing) CPU ID for one apparently overlooked Haswell model in
     the Intel RAPL power capping driver (Srinivas Pandruvada).

   - Fix for the PM core's wakeup IRQs framework to make it work after
     wakeup settings reconfiguration from sysfs (Grygorii Strashko).

   - Runtime PM documentation update to make it describe what needs to
     be done during device removal more precisely (Krzysztof Kozlowski).

   - Stale comment removal cleanup in the cpufreq-dt driver (Viresh
     Kumar).

   - turbostat utility fixes and support for Broxton, Skylake-X and
     Kabylake processors (Len Brown)"

* tag 'pm+acpi-4.6-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (28 commits)
  PM / wakeirq: fix wakeirq setting after wakup re-configuration from sysfs
  tools/power turbostat: work around RC6 counter wrap
  tools/power turbostat: initial KBL support
  tools/power turbostat: initial SKX support
  tools/power turbostat: decode BXT TSC frequency via CPUID
  tools/power turbostat: initial BXT support
  tools/power turbostat: print IRTL MSRs
  tools/power turbostat: SGX state should print only if --debug
  intel_idle: Add KBL support
  intel_idle: Add SKX support
  intel_idle: Clean up all registered devices on exit.
  intel_idle: Propagate hot plug errors.
  intel_idle: Don't overreact to a cpuidle registration failure.
  intel_idle: Setup the timer broadcast only on successful driver load.
  intel_idle: Avoid a double free of the per-CPU data.
  intel_idle: Fix dangling registration on error path.
  intel_idle: Fix deallocation order on the driver exit path.
  intel_idle: Remove redundant initialization calls.
  intel_idle: Fix a helper function's return value.
  intel_idle: remove useless return from void function.
  ...

Pull networking fixes from David Miller:

 1) Stale SKB data pointer access across pskb_may_pull() calls in L2TP,
    from Haishuang Yan.

 2) Fix multicast frame handling in mac80211 AP code, from Felix
    Fietkau.

 3) mac80211 station hashtable insert errors not handled properly, fix
    from Johannes Berg.

 4) Fix TX descriptor count limit handling in e1000, from Alexander
    Duyck.

 5) Revert a buggy netdev refcount fix in netpoll, from Bjorn Helgaas.

 6) Must assign rtnl_link_ops of the device before registering it, fix
    in ip6_tunnel from Thadeu Lima de Souza Cascardo.

 7) Memory leak fix in tc action net exit, from WANG Cong.

 8) Add missing AF_KCM entries to name tables, from Dexuan Cui.

 9) Fix regression in GRE handling of csums wrt.  FOU, from Alexander
    Duyck.

10) Fix memory allocation alignment and congestion map corruption in
    RDS, from Shamir Rabinovitch.

11) Fix default qdisc regression in tuntap driver, from Jason Wang.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (44 commits)
  bridge, netem: mark mailing lists as moderated
  tuntap: restore default qdisc
  mpls: find_outdev: check for err ptr in addition to NULL check
  ipv6: Count in extension headers in skb->network_header
  RDS: fix congestion map corruption for PAGE_SIZE > 4k
  RDS: memory allocated must be align to 8
  GRE: Disable segmentation offloads w/ CSUM and we are encapsulated via FOU
  net: add the AF_KCM entries to family name tables
  MAINTAINERS: intel-wired-lan list is moderated
  lib/test_bpf: Add additional BPF_ADD tests
  lib/test_bpf: Add test to check for result of 32-bit add that overflows
  lib/test_bpf: Add tests for unsigned BPF_JGT
  lib/test_bpf: Fix JMP_JSET tests
  VSOCK: Detach QP check should filter out non matching QPs.
  stmmac: fix adjust link call in case of a switch is attached
  af_packet: tone down the Tx-ring unsupported spew.
  net_sched: fix a memory leak in tc action
  samples/bpf: Enable powerpc support
  samples/bpf: Use llc in PATH, rather than a hardcoded value
  samples/bpf: Fix build breakage with map_perf_test_user.c
  ...

Pull btrfs fixes from Chris Mason:
 "These are bug fixes, including a really old fsync bug, and a few trace
  points to help us track down problems in the quota code"

* 'for-linus-4.6' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  Btrfs: fix file/data loss caused by fsync after rename and new inode
  btrfs: Reset IO error counters before start of device replacing
  btrfs: Add qgroup tracing
  Btrfs: don't use src fd for printk
  btrfs: fallback to vmalloc in btrfs_compare_tree
  btrfs: handle non-fatal errors in btrfs_qgroup_inherit()
  btrfs: Output more info for enospc_debug mount option
  Btrfs: fix invalid reference in replace_path
  Btrfs: Improve FL_KEEP_SIZE handling in fallocate

Pull orangefs fixes from Mike Marshall:
 "Orangefs cleanups and a strncpy vulnerability fix.

  Cleanups:
   - remove an unused variable from orangefs_readdir.
   - clean up printk wrapper used for ofs "gossip" debugging.
   - clean up truncate ctime and mtime setting in inode.c
   - remove a useless null check found by coccinelle.
   - optimize some memcpy/memset boilerplate code.
   - remove some useless sanity checks from xattr.c

  Fix:
   - fix a potential strncpy vulnerability"

* tag 'for-linus-4.6-ofs1' of git://git.kernel.org/pub/scm/linux/kernel/git/hubcap/linux:
  orangefs: remove unused variable
  orangefs: Add KERN_<LEVEL> to gossip_<level> macros
  orangefs: strncpy -> strscpy
  orangefs: clean up truncate ctime and mtime setting
  Orangefs: fix ifnullfree.cocci warnings
  Orangefs: optimize boilerplate code.
  Orangefs: xattr.c cleanup

Pull IOMMU fixes from Joerg Roedel:

 - compile-time fixes (warnings and failures)

 - a bug in iommu core code which could cause the group->domain pointer
   to be falsly cleared

 - fix in scatterlist handling of the ARM common DMA-API code

 - stall detection fix for the Rockchip IOMMU driver

* tag 'iommu-fixes-v4.6-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu:
  iommu/vt-d: Silence an uninitialized variable warning
  iommu/rockchip: Fix "is stall active" check
  iommu: Don't overwrite domain pointer when there is no default_domain
  iommu/dma: Restore scatterlist offsets correctly
  iommu: provide of_xlate pointer unconditionally

Make sure we avoid a division-by-zero OOPS in case clock-frequency is
set too low in DT. Add missing '\n' while we are here.
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Acked-by: Axel Lin <axel.lin@ingics.com>