When the kernel allows tweaking perf_event_max_stack and the event being
setup has PERF_SAMPLE_CALLCHAIN in its perf_event_attr.sample_type, tell
the user that tweaking /proc/sys/kernel/perf_event_max_stack may solve
the problem.

Before:

  # echo 32000 > /proc/sys/kernel/perf_event_max_stack
  # perf record -g usleep 1
  Error:
  The sys_perf_event_open() syscall returned with 12 (Cannot allocate memory) for event (cycles:ppp).
  /bin/dmesg may provide additional information.
  No CONFIG_PERF_EVENTS=y kernel support configured?

  #

After:

  # echo 64000 > /proc/sys/kernel/perf_event_max_stack
  # perf record -g usleep 1
  Error:
  Not enough memory to setup event with callchain.
  Hint: Try tweaking /proc/sys/kernel/perf_event_max_stack
  Hint: Current value: 64000
  #
Suggested-by: NDavid Ahern <dsahern@gmail.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Frederic Weisbecker <fweisbec@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-ebv0orelj1s1ye857vhb82ov@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Coverity flagged this under CID 1354884 as a sizeof mismatch, it turns
out that the argument "attr" passed to syscall should have been a
pointer to attr in the first place.

Reported-by: coverity (CID 1354884)
Signed-off-by: NFlorian Fainelli <f.fainelli@gmail.com>
Acked-by: NAlexei Starovoitov <ast@kernel.org>
Acked-by: NWang Nan <wangnan0@huawei.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Fixes: 8f9e05fb ("perf tools: Fix PowerPC native building")
Link: http://lkml.kernel.org/r/1461551694-5512-3-git-send-email-f.fainelli@gmail.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Assigning "attr" to "attr" does not have any effect, but was caught by
Coverity, so let's remove this.

Reported-by: coverity (CID 1354720)
Signed-off-by: NFlorian Fainelli <f.fainelli@gmail.com>
Tested-by: NWang Nan <wangnan0@huawei.com>
Acked-by: NAlexei Starovoitov <ast@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Fixes: 1b76c13e ("bpf tools: Introduce 'bpf' library and add bpf feature check")
Link: http://lkml.kernel.org/r/1461551694-5512-2-git-send-email-f.fainelli@gmail.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Skylake processor supports a new set of RAPL registers for controlling
entire SoC instead of just CPU package. This is useful for thermal
and power control when source of power/thermal is not just CPU/GPU.
This change adds a new platform domain (AKA PSys) to the current
power capping Intel RAPL driver.

PSys also supports PL1 (long term) and PL2 (short term) control like
package domain. This also follows same MSRs for energy and time
units as package domain.

Unlike package domain, PSys support requires more than just processor
level implementation. The other parts in the system need additional
implementation, which OEMs needs to support. So not all Skylake
systems will support PSys.
Signed-off-by: NSrinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: bp@alien8.de
Cc: hpa@zytor.com
Cc: jacob.jun.pan@linux.intel.com
Cc: rjw@rjwysocki.net
Link: http://lkml.kernel.org/r/1460930581-29748-3-git-send-email-srinivas.pandruvada@linux.intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

 Conflicts:
	arch/x86/events/intel/pt.c
Signed-off-by: NIngo Molnar <mingo@kernel.org>

This patch fixes a bug which was introduced by:

 b16a5b52 ("perf/x86: Add option to disable reading branch flags/cycles")

In this patch, lbr_sel_mask is used to mask the lbr_select. But LBR_SEL_MASK
doesn't include the bit for LBR_CALL_STACK. So LBR call stack will never be
set in lbr_select.

This patch corrects the LBR_SEL_MASK by including all valid bits in
LBR_SELECT. Also, the LBR_CALL_STACK bit is different as other bit in
LBR_SELECT. It does not operate in suppress mode, so it needs to be
specially handled in intel_pmu_setup_hw_lbr_filter.
Signed-off-by: NKan Liang <kan.liang@intel.com>
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Link: http://lkml.kernel.org/r/1461231010-4399-1-git-send-email-kan.liang@intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

Some versions of Intel PT do not support tracing across VMXON, more
specifically, VMXON will clear TraceEn control bit and any attempt to
set it before VMXOFF will throw a #GP, which in the current state of
things will crash the kernel. Namely:

  $ perf record -e intel_pt// kvm -nographic

on such a machine will kill it.

To avoid this, notify the intel_pt driver before VMXON and after
VMXOFF so that it knows when not to enable itself.
Signed-off-by: NAlexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: hpa@zytor.com
Link: http://lkml.kernel.org/r/87oa9dwrfk.fsf@ashishki-desk.ger.corp.intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

Jann reported that the ptrace_may_access() check in
find_lively_task_by_vpid() is racy against exec().

Specifically:

  perf_event_open()		execve()

  ptrace_may_access()
				commit_creds()
  ...				if (get_dumpable() != SUID_DUMP_USER)
				  perf_event_exit_task();
  perf_install_in_context()

would result in installing a counter across the creds boundary.

Fix this by wrapping lots of perf_event_open() in cred_guard_mutex.
This should be fine as perf_event_exit_task() is already called with
cred_guard_mutex held, so all perf locks already nest inside it.
Reported-by: NJann Horn <jannh@google.com>
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: NIngo Molnar <mingo@kernel.org>

The entry for PERF_COUNT_HW_REF_CPU_CYCLES is not used on AMD, but is
referenced by filter_events() which expects undefined events to have a
value of 0.

Found via KASAN:

  UBSAN: Undefined behaviour in arch/x86/events/amd/core.c:132:30
  index 9 is out of range for type 'u64 [9]'
  UBSAN: Undefined behaviour in arch/x86/events/amd/core.c:132:9
  load of address ffffffff81c021c8 with insufficient space for an object of type 'const u64'
Signed-off-by: NAdam Borowski <kilobyte@angband.pl>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Link: http://lkml.kernel.org/r/1461749731-30979-1-git-send-email-kilobyte@angband.plSigned-off-by: NIngo Molnar <mingo@kernel.org>

Merge tag 'perf-core-for-mingo-20160427' 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:

- perf trace --pf maj/min/all works with --call-graph: (Arnaldo Carvalho de Melo)

  Tracing write syscalls and major page faults with callchains while starting
  firefox, limiting the stack to 5 frames:

 # perf trace -e write --pf maj --max-stack 5 firefox
   589.549 ( 0.014 ms): firefox/15377 write(fd: 4, buf: 0x7fff80acc898, count: 151) = 151
                                       [0xfaed] (/usr/lib64/libpthread-2.22.so)
                                       fire_glxtest_process+0x5c (/usr/lib64/firefox/libxul.so)
                                       InstallGdkErrorHandler+0x41 (/usr/lib64/firefox/libxul.so)
                                       XREMain::XRE_mainInit+0x12c (/usr/lib64/firefox/libxul.so)
                                       XREMain::XRE_main+0x1e4 (/usr/lib64/firefox/libxul.so)
   760.704 ( 0.000 ms): firefox/15332 majfault [gtk_tree_view_accessible_get_type+0x0] => /usr/lib64/libgtk-3.so.0.1800.9@0xa0850 (x.)
                                       gtk_tree_view_accessible_get_type+0x0 (/usr/lib64/libgtk-3.so.0.1800.9)
                                       gtk_tree_view_class_intern_init+0x1a54 (/usr/lib64/libgtk-3.so.0.1800.9)
                                       g_type_class_ref+0x6dd (/usr/lib64/libgobject-2.0.so.0.4600.2)
                                       [0x115378] (/usr/lib64/libgnutls.so.30.6.3)

  This automagically selects "--call-graph dwarf", use "--call-graph fp" on systems
  where -fno-omit-frame-pointer was used to built the components of interest, to
  incur in less overhead, or tune "--call-graph dwarf" appropriately, see 'perf record --help'.

- Allow /proc/sys/kernel/perf_event_max_stack, that defaults to the old hard coded value
  of PERF_MAX_STACK_DEPTH (127), useful for huge callstacks for things like Groovy, Ruby, etc,
  and also to reduce overhead by limiting it to a smaller value, upcoming work will allow
  this to be done per-event (Arnaldo Carvalho de Melo)

- Make 'perf trace --min-stack' be honoured by --pf and --event (Arnaldo Carvalho de Melo)

- Make 'perf evlist -v' decode perf_event_attr->branch_sample_type (Arnaldo Carvalho de Melo)

   # perf record --call lbr usleep 1
   # perf evlist -v
   cycles:ppp: ... sample_type: IP|TID|TIME|CALLCHAIN|PERIOD|BRANCH_STACK, ...
            branch_sample_type: USER|CALL_STACK|NO_FLAGS|NO_CYCLES
   #

- Clear dummy entry accumulated period, fixing such 'perf top/report' output
  as: (Kan Liang)

    4769.98%  0.01%  0.00%  0.01%  tchain_edit  [kernel] [k] update_fast_timekeeper

- System calls with pid_t arguments gets them augmented with the COMM event
  more thoroughly:

  # trace -e perf_event_open perf stat -e cycles -p 15608
   6.876 ( 0.014 ms): perf_event_open(attr_uptr: 0x2ae20d8, pid: 15608 (hexchat), cpu: -1, group_fd: -1, flags: FD_CLOEXEC) = 3
   6.882 ( 0.005 ms): perf_event_open(attr_uptr: 0x2ae20d8, pid: 15639 (gmain), cpu: -1, group_fd: -1, flags: FD_CLOEXEC) = 4
   6.889 ( 0.005 ms): perf_event_open(attr_uptr: 0x2ae20d8, pid: 15640 (gdbus), cpu: -1, group_fd: -1, flags: FD_CLOEXEC) = 5
                                                            ^^^^^^^^^^^^^^^^^^
   ^C

- Fix offline module name mismatch issue in 'perf probe' (Ravi Bangoria)

- Fix module probe issue if no dwarf support in (Ravi Bangoria)

Assorted fixes:

- Fix off-by-one in write_buildid() (Andrey Ryabinin)

- Fix segfault when printing callchains in 'perf script' (Chris Phlipot)

- Replace assignment with comparison on assert check in 'perf test' entry (Colin Ian King)

- Fix off-by-one comparison in intel-pt code (Colin Ian King)

- Close target file on error path in 'perf probe' (Masami Hiramatsu)

- Set default kprobe group name if not given in 'perf probe' (Masami Hiramatsu)

- Avoid partial perf_event_header reads (Wang Nan)

Infrastructure changes:

- Update x86's syscall_64.tbl copy, adding preadv2 & pwritev2 (Arnaldo Carvalho de Melo)

- Make the x86 clean quiet wrt syscall table removal (Jiri Olsa)

Cleanups:

- Simplify wrapper for LOCK_PI in 'perf bench futex' (Davidlohr Bueso)

- Remove duplicate const qualifier (Eric Engestrom)
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: NIngo Molnar <mingo@kernel.org>

There is an upper limit to what tooling considers a valid callchain,
and it was tied to the hardcoded value in the kernel,
PERF_MAX_STACK_DEPTH (127), now that this can be tuned via a sysctl,
make it read it and use that as the upper limit, falling back to
PERF_MAX_STACK_DEPTH for kernels where this sysctl isn't present.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@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-yjqsd30nnkogvj5oyx9ghir9@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

The default remains 127, which is good for most cases, and not even hit
most of the time, but then for some cases, as reported by Brendan, 1024+
deep frames are appearing on the radar for things like groovy, ruby.

And in some workloads putting a _lower_ cap on this may make sense. One
that is per event still needs to be put in place tho.

The new file is:

  # cat /proc/sys/kernel/perf_event_max_stack
  127

Chaging it:

  # echo 256 > /proc/sys/kernel/perf_event_max_stack
  # cat /proc/sys/kernel/perf_event_max_stack
  256

But as soon as there is some event using callchains we get:

  # echo 512 > /proc/sys/kernel/perf_event_max_stack
  -bash: echo: write error: Device or resource busy
  #

Because we only allocate the callchain percpu data structures when there
is a user, which allows for changing the max easily, its just a matter
of having no callchain users at that point.
Reported-and-Tested-by: NBrendan Gregg <brendan.d.gregg@gmail.com>
Reviewed-by: NFrederic Weisbecker <fweisbec@gmail.com>
Acked-by: NAlexei Starovoitov <ast@kernel.org>
Acked-by: NDavid Ahern <dsahern@gmail.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: Wang Nan <wangnan0@huawei.com>
Cc: Zefan Li <lizefan@huawei.com>
Link: http://lkml.kernel.org/r/20160426002928.GB16708@kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Propagate the error instead.

Cc: David Ahern <dsahern@gmail.com>
Cc: Hitoshi Mitake <mitake@dcl.info.waseda.ac.jp>
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-z6erjg35d1gekevwujoa0223@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Introduced in commit 4babf2c5 ("x86: wire up preadv2 and pwritev2").

This will make 'perf trace' aware of them.

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-vojoylgce2cetsy36446s5ny@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Perf is not able to register probe in kernel module when dwarf supprt
is not there(and so it goes for symtab). Perf passes full path of
module where only module name is required which is causing the problem.
This patch fixes this issue.

Before applying patch:

  $ dpkg -s libdw-dev
  dpkg-query: package 'libdw-dev' is not installed and no information is...

  $ sudo ./perf probe -m /linux/samples/kprobes/kprobe_example.ko kprobe_init
  Added new event:
    probe:kprobe_init (on kprobe_init in /linux/samples/kprobes/kprobe_example.ko)

  You can now use it in all perf tools, such as:

  perf record -e probe:kprobe_init -aR sleep 1

  $ sudo cat /sys/kernel/debug/tracing/kprobe_events
  p:probe/kprobe_init /linux/samples/kprobes/kprobe_example.ko:kprobe_init

  $ sudo ./perf record -a -e probe:kprobe_init
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.105 MB perf.data ]

  $ sudo ./perf script 	# No output here

After applying patch:

  $ sudo ./perf probe -m /linux/samples/kprobes/kprobe_example.ko kprobe_init
  Added new event:
    probe:kprobe_init    (on kprobe_init in kprobe_example)

  You can now use it in all perf tools, such as:

  perf record -e probe:kprobe_init -aR sleep 1

  $ sudo cat /sys/kernel/debug/tracing/kprobe_events
  p:probe/kprobe_init kprobe_example:kprobe_init

  $ sudo ./perf record -a -e probe:kprobe_init
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.105 MB perf.data (2 samples) ]

  $ sudo ./perf script
  insmod 13990 [002]  5961.216833: probe:kprobe_init: ...
  insmod 13995 [002]  5962.889384: probe:kprobe_init: ...
Signed-off-by: NRavi Bangoria <ravi.bangoria@linux.vnet.ibm.com>
Acked-by: NMasami Hiramatsu <mhiramat@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/1461680741-12517-1-git-send-email-ravi.bangoria@linux.vnet.ibm.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Perf can add a probe on kernel module which has not been loaded yet.

The current implementation finds the module name from path. But if the
filename is different from the actual module name then perf fails to
register a probe while loading module because of mismatch in the names.

For example, samples/kobject/kobject-example.ko is loaded as
kobject_example.

Before applying patch:

  $ sudo ./perf probe -m /linux/samples/kobject/kobject-example.ko foo_show
    Added new event:
      probe:foo_show       (on foo_show in kobject-example)

    You can now use it in all perf tools, such as:

    perf record -e probe:foo_show -aR sleep 1

  $ cat /sys/kernel/debug/tracing/kprobe_events
    p:probe/foo_show kobject-example:foo_show

  $ insmod kobject-example.ko

  $ lsmod
    Module                  Size  Used by
    kobject_example        16384  0

  Generate read to /sys/kernel/kobject_example/foo while recording data
  with below command
  $ sudo ./perf record -e probe:foo_show -a
    [ perf record: Woken up 1 times to write data ]
    [ perf record: Captured and wrote 0.093 MB perf.data ]

  $./perf report --stdio -F overhead,comm,dso,sym
    Error:
    The perf.data.old file has no samples!

After applying patch:

  $ sudo ./perf probe -m /linux/samples/kobject/kobject-example.ko foo_show
    Added new event:
      probe:foo_show       (on foo_show in kobject_example)

    You can now use it in all perf tools, such as:

    perf record -e probe:foo_show -aR sleep 1

  $ sudo cat /sys/kernel/debug/tracing/kprobe_events
    p:probe/foo_show kobject_example:foo_show

  $ insmod kobject-example.ko

  $ lsmod
    Module                  Size  Used by
    kobject_example        16384  0

  Generate read to /sys/kernel/kobject_example/foo while recording data
  with below command
  $ sudo ./perf record -e probe:foo_show -a
    [ perf record: Woken up 1 times to write data ]
    [ perf record: Captured and wrote 0.097 MB perf.data (8 samples) ]

  $ sudo ./perf report  --stdio -F overhead,comm,dso,sym
    ...
    # Samples: 8  of event 'probe:foo_show'
    # Event count (approx.): 8
    #
    # Overhead  Command  Shared Object      Symbol
    # ........  .......  .................  ............
    #
       100.00%  cat      [kobject_example]  [k] foo_show
Signed-off-by: NRavi Bangoria <ravi.bangoria@linux.vnet.ibm.com>
Acked-by: NMasami Hiramatsu <mhiramat@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/1461680741-12517-2-git-send-email-ravi.bangoria@linux.vnet.ibm.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

We get notifications for threads that gets created while we're tracing,
but for preexisting threads we may end not having synthesized them, like
when tracing a 'perf trace' session that will use '--pid' to trace some
other thread.

And besides we should probably stop synthesizing those records and
instead read thread information in a lazy way, i.e. just when we need,
like done in this patch:

Now the 'pid_t' argument in 'perf_event_open' gets translated to a COMM:

  # perf trace -e perf_event_open perf stat -e cycles -p 31601
     0.027 ( 0.027 ms): perf/23393 perf_event_open(attr_uptr: 0x2fdd0d8, pid: 31601 (abrt-dump-journ), cpu: -1, group_fd: -1, flags: FD_CLOEXEC)
                                                                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
= 3
^C

And in other syscalls containing pid_t without thread->comm_set at the
time of the formatting.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
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-ioeps6dlwst17d6oozc9shtk@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Will be used for lazy comm loading in 'perf trace'.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
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-7ogbkuoka1y2qsmcckqxvl5m@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

To read things like /proc/self/comm.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
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-ztpkbmseidt0hq2psr46o0h9@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Leave it alone so that it ends up assigned to SCA_PID via its type,
'pid_t', that will look up the pid on the machine thread rb_tree and
possibly find its COMM.

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-r7dujgmhtxxfajuunpt1bkuo@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

To reduce the size of builtin-trace.c.

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-8r3gmymyn3r0ynt4yuzspp9g@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Set kprobe group name as "probe" if it is not given.
Signed-off-by: NMasami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: NMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>
Cc: Hemant Kumar <hemant@linux.vnet.ibm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20160426090413.11891.95640.stgit@devboxSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Since other methods return 0 if succeeded (or filedesc), let
probe_file__add_event() return 0 instead of the length of written bytes.
Signed-off-by: NMasami Hiramatsu <mhiramat@kernel.org>
Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>
Cc: Hemant Kumar <hemant@linux.vnet.ibm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20160426090303.11891.18232.stgit@devboxSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

As a utility function, add lsdir() which reads given directory and store
entry name into a strlist.  lsdir accepts a filter function so that user
can filter out unneeded entries.
Signed-off-by: NMasami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: NMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>
Cc: Hemant Kumar <hemant@linux.vnet.ibm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20160426090242.11891.79014.stgit@devbox
[ Do not use the 'dirname' it is used in some distros ]
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Fix a bug to close target elf file in get_text_start_address().
Signed-off-by: NMasami Hiramatsu <mhiramat@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20160426064737.1443.44093.stgit@devboxSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Don't read broken data after 'head' pointer.

Following commits will feed perf_evlist__mmap_read() with some 'head'
pointers not maintained by kernel. If 'head' pointer breaks an event, we
should avoid reading from the broken event. This can happen in backward
ring buffer.

For example:

                              old     head
                                |     |
                                V     V
     +---+------+----------+----+-----+--+
     |..E|D....D|C........C|B..B|A....|E.|
     +---+------+----------+----+-----+--+

'old' pointer points to the beginning of 'A' and trying read from it,
but 'A' has been overwritten. In this case, don't try to read from 'A',
simply return NULL.
Signed-off-by: NWang Nan <wangnan0@huawei.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1461637738-62722-2-git-send-email-wangnan0@huawei.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

The accumulated period for dummy entry should also be 0.  Otherwise, the
total overhead could be overcounted.

  $ perf record -e '{LLC-load-misses,cpu/instructions/}' --call-graph=lbr ./tchain
  $ perf report --stdio
  # To display the perf.data header info, please use --header/--header-only options.
  #
  # Total Lost Samples: 0
  #
  # Samples: 21K of event 'anon group { LLC-load-misses, cpu/instructions/ }'
  # Event count (approx.): 16313667937
  #
  #         Children              Self  Command      Shared Object     Symbol
  # ................  ................  ...........  ................  ............................
  #
    4769.98%   0.01%     0.00%   0.01%  tchain_edit  [kernel.vmlinux]  [k] update_fast_timekeeper
    4356.18%   0.01%     0.00%   0.01%  tchain_edit  [kernel.vmlinux]  [k] trigger_load_balance
    3181.12%   0.01%     0.00%   0.01%  tchain_edit  [kernel.vmlinux]  [k] irq_work_tick
    1592.37%   0.00%     0.00%   0.00%  tchain_edit  [kernel.vmlinux]  [k] cpu_needs_another_gp
Signed-off-by: NKan Liang <kan.liang@intel.com>
Acked-by: NJiri Olsa <jolsa@kernel.org>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/r/1461565689-5862-1-git-send-email-kan.liang@intel.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

The check for the maximum code is off-by-one; the current comparison of
a code that is INTEL_PT_ERR_MAX will cause the strlcpy to perform an out
of bounds array access on the intel_pt_err_msgs array.

Fix this with a >= comparison.
Signed-off-by: NColin Ian King <colin.king@canonical.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1461524203-10224-1-git-send-email-colin.king@canonical.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Given that the 'val' parameter is ignored for FUTEX_LOCK_PI, get rid of
the bogus deadlock detection flag in the wrapper code and avoid the
extra argument, making it resemble its unlock counterpart. And if
nothing else, we already only pass 0 anyway.
Signed-off-by: NDavidlohr Bueso <dbueso@suse.de>
Cc: Davidlohr Bueso <dbueso@suse.de>
Link: http://lkml.kernel.org/r/1461208447-29328-1-git-send-email-dave@stgolabs.netSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

The current assert check is checking an assignment, which will always be
true.  Instead, the assert should be checking if scale is equal to 0.122
Signed-off-by: NColin Ian King <colin.king@canonical.com>
Reviewed-by: NMasami Hiramatsu <mhiramat@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1461419154-16918-1-git-send-email-colin.king@canonical.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Signed-off-by: NEric Engestrom <eric.engestrom@imgtec.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1461577678-29517-1-git-send-email-eric.engestrom@imgtec.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Fix perf_clean target to follow the same logic as perf target.

Fixes the following make invokation:

  $ cd <kernelsrc> && make tools/perf_clean
Reported-by: NTJ <linux@iam.tj>
Signed-off-by: NJiri Olsa <jolsa@kernel.org>
Tested-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=116411
Link: http://lkml.kernel.org/r/1461615438-27894-2-git-send-email-jolsa@kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Turn current clean output:

  $ make clean
  rm -f arch/x86/include/generated/asm/syscalls_64.c
    CLEAN    libbpf
    CLEAN    libapi

into:

  $ make clean
    CLEAN    x86
    CLEAN    libapi
    CLEAN    libbpf
Signed-off-by: NJiri Olsa <jolsa@kernel.org>
Tested-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: TJ <linux@iam.tj>
Link: http://lkml.kernel.org/r/1461615438-27894-1-git-send-email-jolsa@kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

While trying to use --call-graph lbr in 'perf trace', since we only are
interested in the callchain for userspace, up to the callchain, I found
that 'perf evlist' is not decoding the branch_sample_type field, fix it.

Before:

  # perf record --call-graph lbr usleep 1
  # perf evlist -v
  cycles:ppp: size: 112, { sample_period, sample_freq }: 4000,
  sample_type: IP|TID|TIME|CALLCHAIN|CPU|PERIOD|BRANCH_STACK,
  disabled: 1, inherit: 1, mmap: 1, comm: 1, freq: 1, task: 1,
  precise_ip: 3, sample_id_all: 1, exclude_guest: 1, mmap2: 1,
  comm_exec: 1, branch_sample_type: 51201
                ^^^^^^^^^^^^^^^^^^^^^^^^^

After:

  # perf evlist -v
  cycles:ppp: size: 112, { sample_period, sample_freq }: 4000,
  sample_type: IP|TID|TIME|CALLCHAIN|CPU|PERIOD|BRANCH_STACK,
  disabled: 1, inherit: 1, mmap: 1, comm: 1, freq: 1, task: 1,
  precise_ip: 3, sample_id_all: 1, exclude_guest: 1, mmap2: 1,
  comm_exec: 1, branch_sample_type: USER|CALL_STACK|NO_FLAGS|NO_CYCLES
                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

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-hozai7974u0ulgx13k96fcaw@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

To check deeply nested page fault callchains.

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-wuji34xx003kr88nmqt6jkgf@git.kernel.orgSigned-off-by: NArnaldo 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: 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-shj0fazntmskhjild5i6x73l@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

This fixes a bug caused by an unitialized callchain cursor. The crash
frist appeared in:

6f736735 ("perf evsel: Require that callchains be resolved before
calling fprintf_{sym,callchain}")

The callchain cursor is a struct that contains pointers, that when
uninitialized will cause unpredictable behavior (usually a crash)
when trying to append to the callchain.

The existing implementation has the following issues:

1. The callchain cursor used is not initialized, resulting in
	unpredictable behavior when used.
2. The cursor is declared on the stack. Even if it is properly initalized,
	the implmentation will leak memory when the function returns,
	since all the references to the callchain_nodes allocated by
	callchain_cursor_append will be lost when the cursor goes out of
	scope.
3. Storing the cursor on the stack is inefficient. Even if memory is
	properly freed when it goes out of scope, a performance penalty
	will be incurred due to reallocation of callchain nodes.
	callchain_cursor_append is designed to avoid these reallocations
	when an existing cursor is reused.

This patch fixes the crash by replacing cursor_callchain with a reference
to the global callchain_cursor which also resolves all 3 issues mentioned
above.

How to reproduce the crash:

  $ perf record --call-graph=dwarf stress -t 1 -c 1
  $ perf script > /dev/null
  Segfault
Signed-off-by: NChris Phlipot <cphlipot0@gmail.com>
Tested-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Fixes: 6f736735 ("perf evsel: Require that callchains be resolved before calling fprintf_{sym,callchain}")
Link: http://lkml.kernel.org/r/1461119531-2529-1-git-send-email-cphlipot0@gmail.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Forgot about page faults, a software event, when adding support for callchains,
fix it:

  # trace --no-syscalls --pf maj --call dwarf
     0.000 ( 0.000 ms): Xorg/2068 majfault [sfbSegment1+0x0] => /usr/lib64/xorg/modules/drivers/intel_drv.so@0x11b490 (x.)
                                       sfbSegment1+0x0 (/usr/lib64/xorg/modules/drivers/intel_drv.so)
                                       fbPolySegment32+0x361 (/usr/lib64/xorg/modules/drivers/intel_drv.so)
                                       sna_poly_segment+0x743 (/usr/lib64/xorg/modules/drivers/intel_drv.so)
                                       damagePolySegment+0x77 (/usr/libexec/Xorg)
                                       ProcPolySegment+0xe7 (/usr/libexec/Xorg)
                                       Dispatch+0x25f (/usr/libexec/Xorg)
                                       dix_main+0x3c3 (/usr/libexec/Xorg)
                                       __libc_start_main+0xf0 (/usr/lib64/libc-2.22.so)
                                       _start+0x29 (/usr/libexec/Xorg)
     0.257 ( 0.000 ms): Xorg/2068 majfault [miZeroClipLine+0x0] => /usr/libexec/Xorg@0x18e830 (x.)
                                       miZeroClipLine+0x0 (/usr/libexec/Xorg)
                                       _fbSegment+0x2c0 (/usr/lib64/xorg/modules/drivers/intel_drv.so)
                                       sfbSegment1+0x67 (/usr/lib64/xorg/modules/drivers/intel_drv.so)
                                       fbPolySegment32+0x361 (/usr/lib64/xorg/modules/drivers/intel_drv.so)
                                       sna_poly_segment+0x743 (/usr/lib64/xorg/modules/drivers/intel_drv.so)
                                       damagePolySegment+0x77 (/usr/libexec/Xorg)
                                       ProcPolySegment+0xe7 (/usr/libexec/Xorg)
                                       Dispatch+0x25f (/usr/libexec/Xorg)
                                       dix_main+0x3c3 (/usr/libexec/Xorg)
                                       __libc_start_main+0xf0 (/usr/lib64/libc-2.22.so)
                                       _start+0x29 (/usr/libexec/Xorg)
^C#

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-8h6ssirw5z15qyhy2lwd6f89@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Prep work for next patches, where we'll need access to the created
evsels, to possibly configure callchains.

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-2pcgsgnkgellhlcao4aub8tu@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

write_buildid() increments 'name_len' with intention to take into
account trailing zero byte. However, 'name_len' was already incremented
in machine__write_buildid_table() before.  So this leads to
out-of-bounds read in do_write():

  $ ./perf record sleep 0
  [ perf record: Woken up 1 times to write data ]
  =================================================================
  ==15899==ERROR: AddressSanitizer: global-buffer-overflow on address 0x00000099fc92 at pc 0x7f1aa9c7eab5 bp 0x7fff940f84d0 sp 0x7fff940f7c78
  READ of size 19 at 0x00000099fc92 thread T0
      #0 0x7f1aa9c7eab4  (/usr/lib/gcc/x86_64-pc-linux-gnu/5.3.0/libasan.so.2+0x44ab4)
      #1 0x649c5b in do_write util/header.c:67
      #2 0x649c5b in write_padded util/header.c:82
      #3 0x57e8bc in write_buildid util/build-id.c:239
      #4 0x57e8bc in machine__write_buildid_table util/build-id.c:278
  ...

  0x00000099fc92 is located 0 bytes to the right of global variable '*.LC99' defined in 'util/symbol.c' (0x99fc80) of size 18
    '*.LC99' is ascii string '[kernel.kallsyms]'
  ...

  Shadow bytes around the buggy address:
    0x00008012bf80: f9 f9 f9 f9 00 00 00 00 00 00 03 f9 f9 f9 f9 f9
  =>0x00008012bf90: 00 00[02]f9 f9 f9 f9 f9 00 00 00 00 00 05 f9 f9
    0x00008012bfa0: f9 f9 f9 f9 00 03 f9 f9 f9 f9 f9 f9 00 00 00 00
Signed-off-by: NAndrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1461053847-5633-1-git-send-email-aryabinin@virtuozzo.com
[ Remove the off-by one at the origin, to keep len(s) == strlen(s) assumption ]
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>