When record__mmap_read() requires data more than the size of ring
buffer, drop those data to avoid accessing invalid memory.

This can happen when reading from overwritable ring buffer, which
should be avoided. However, check this for robustness.
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1463987628-163563-3-git-send-email-wangnan0@huawei.comSigned-off-by: He Kuang <hekuang@huawei.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf_evlist__toggle_{pause,resume}() are introduced to pause/resume
events in an evlist. Utilize PERF_EVENT_IOC_PAUSE_OUTPUT ioctl.

Following commits use them to ensure overwrite ring buffer is paused
before reading.
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1463987628-163563-2-git-send-email-wangnan0@huawei.comSigned-off-by: He Kuang <hekuang@huawei.com>
[ Return -1, like all other ioctl() usage in evlist.c, rename 'pause'
  arg to avoid breaking the build on ubuntu 12.04 and other old systems ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Auto-attach the ptr->name beautifier to syscall args "filename", "path"
and "pathname" if they are of type "const char *".

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-jxii4qmcgoppftv0zdvml9d7@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Noticed when the 'setsockopt' 'fd' arg wasn't being formatted via
the SCA_FD beautifier, so just remove the setting of "fd" args to
SCA_FD and do it when reading the syscall info, like we do for
args of type "pid_t", i.e. "fd" as the name should be enough as
the decision to use the SFA_FD beautifier. For odd cases we can
just do it explicitely.

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-0qissgetiuqmqyj4b6ancmpn@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Add "srcline_from" and "srcline_to" branch sort keys that allow to show
the source lines of a branch.

That makes it much easier to track down where particular branches happen
in the program, for example to examine branch mispredictions, or to
associate it with cycle counts:

  % perf record -b -e cycles:p ./tcall
  % perf report --sort srcline_from,srcline_to,mispredict
  ...
    15.10%  tcall.c:18       tcall.c:10       N
    14.83%  tcall.c:11       tcall.c:5        N
    14.12%  tcall.c:7        tcall.c:12       N
    14.04%  tcall.c:12       tcall.c:5        N
    12.42%  tcall.c:17       tcall.c:18       N
    12.39%  tcall.c:7        tcall.c:13       N
    12.27%  tcall.c:13       tcall.c:17       N
  ...

  % perf report --sort srcline_from,srcline_to,cycles
  ...
    17.12%  tcall.c:18       tcall.c:11       1
    17.01%  tcall.c:12       tcall.c:6        1
    16.98%  tcall.c:11       tcall.c:6        1
    15.91%  tcall.c:17       tcall.c:18       1
     6.38%  tcall.c:7        tcall.c:17       7
     4.80%  tcall.c:7        tcall.c:12       8
     4.21%  tcall.c:7        tcall.c:17       8
     2.67%  tcall.c:7        tcall.c:12       7
     2.62%  tcall.c:7        tcall.c:12       10
     2.10%  tcall.c:7        tcall.c:17       9
     1.58%  tcall.c:7        tcall.c:12       6
     1.44%  tcall.c:7        tcall.c:12       5
     1.38%  tcall.c:7        tcall.c:12       9
     1.06%  tcall.c:7        tcall.c:17       13
     1.05%  tcall.c:7        tcall.c:12       4
     1.01%  tcall.c:7        tcall.c:17       6

Open issues:

- Some kernel symbols get misresolved.
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Link: http://lkml.kernel.org/r/1463775308-32748-1-git-send-email-andi@firstfloor.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Add a fd field into struct perf_mmap so that perf can track the mmap fd.

This feature will be used for toggling overwrite ring buffers.
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1463762315-155689-3-git-send-email-wangnan0@huawei.comSigned-off-by: He Kuang <hekuang@huawei.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Add 'overwrite' attribute to evsel to mark whether this event is
overwritable. The following commits will support syntax like:

  # perf record -e cycles/overwrite/ ...

An overwritable evsel requires kernel support for the
perf_event_attr.write_backward ring buffer feature.

Add it to perf_missing_feature.
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1463762315-155689-2-git-send-email-wangnan0@huawei.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Merge tag 'perf-core-for-mingo-20160520' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/urgent

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

User visible changes:

- We should not use the current value of the kernel.perf_event_max_stack as the
  default value for --max-stack in tools that can process perf.data files, they
  will only match if that sysctl wasn't changed from its default value at the
  time the perf.data file was recorded, fix it.

  This fixes a bug where a 'perf record -a --call-graph dwarf ; perf report'
  produces a glibc invalid free backtrace (Arnaldo Carvalho de Melo)

- Provide a better warning when running 'perf trace' on a system where the
  kernel.kptr_restrict is set to 1, similar to the one produced by 'perf record',
  noticed on ubuntu 16.04 where this is the default kptr_restrict setting.
  (Arnaldo Carvalho de Melo)

- Fix ordering of instructions in the annotation code, noticed when annotating
  ARM binaries, now that table is auto-ordered at first use, to avoid more such
  problems (Chris Ryder)

- Set buildid dir under symfs when --symfs is provided (He Kuang)

- Fix the 'exit_group()' syscall output in 'perf trace' (Arnaldo Carvalho de Melo)

- Only auto set call-graph to "dwarf" in 'perf trace' when syscalls are being
  traced (Arnaldo Carvalho de Melo)
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

This patch moves the reference of buildid dir to 'symfs/.debug' and
skips the local buildid dir when '--symfs' is given, so that every
single file opened by perf is relative to symfs directory now.
Signed-off-by: He Kuang <hekuang@huawei.com>
Acked-by: David Ahern <dsahern@gmail.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ekaterina Tumanova <tumanova@linux.vnet.ibm.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Kan Liang <kan.liang@intel.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/1463658462-85131-2-git-send-email-hekuang@huawei.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

When --min-stack or --max-stack is passwd but --no-syscalls is also in
effect, there is no point in automatically setting '--call-graph dwarf'.

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-pq922i7h9wef0pho1dqpttvn@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Currently the list of instructions recognised by perf annotate has to be
explicitly written in sorted order. This makes it easy to make mistakes
when adding new instructions. Sort the list of instructions on first
access.
Signed-off-by: Chris Ryder <chris.ryder@arm.com>
Acked-by: Pawel Moll <pawel.moll@arm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Link: http://lkml.kernel.org/r/4268febaf32f47f322c166fb2fe98cfec7041e11.1463676839.git.chris.ryder@arm.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

The ARM blt and bls instructions are not correctly identified when
parsing assembly because the list of recognised instructions must be
sorted by name. Swap the ordering of blt and bls.
Signed-off-by: Chris Ryder <chris.ryder@arm.com>
Acked-by: Pawel Moll <pawel.moll@arm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Link: http://lkml.kernel.org/r/560e196b7c79b7ff853caae13d8719a31479cb1a.1463676839.git.chris.ryder@arm.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

We cannot limit processing stacks from the current value of the sysctl,
as we may be processing perf.data files, possibly from other machines.

Instead use the old PERF_MAX_STACK_DEPTH, the sysctl default, that can
be overriden using --max-stack or equivalent.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jiri Olsa <jolsa@redhat.com>
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>
Fixes: 4cb93446 ("perf tools: Set the maximum allowed stack from /proc/sys/kernel/perf_event_max_stack")
Link: http://lkml.kernel.org/n/tip-eqeutsr7n7wy0c36z24ytvii@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

As thread__resolve_callchain_sample can be used for handling perf.data
files, that could've been recorded with a large max_stack sysctl setting
than what the system used for analysis has set.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jiri Olsa <jolsa@redhat.com>
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/n/tip-2995bt2g5yq2m05vga4kip6m@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

This doesn't return, so there is no raw_syscalls:sys_exit for it, add
the ending ')', without any return value, since it is void.
Reported-by: Ingo Molnar <mingo@kernel.org>
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-vh2mii0g4qlveuc4joufbipu@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Its now there, no need to have it too.

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-y18oeou494uy11im7u9to0dx@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Hook into the libtraceevent plugin kernel symbol resolver to warn the
user that that can't happen with kptr_restrict=1.

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-9gc412xx1gl0lvqj1d1xwlyb@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

This means the user can't access /proc/kallsyms, for instance, because
/proc/sys/kernel/kptr_restrict is set to 1.

Instead leave the ref_reloc_sym as NULL and code using it will cope.

This allows 'perf trace' to work on such systems for !root, the only
issue would be when trying to resolve kernel symbols, which happens,
for instance, in some libtracevent plugins.  A warning for that case
will be provided in the next patch in this series.

Noticed in Ubuntu 16.04, that comes with kptr_restrict=1.
Reported-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-knpu3z4iyp2dxpdfm798fac4@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Remove an extraneous space to fix up indentation. Trivial and no
functional change
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bp@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1463503215-18339-1-git-send-email-colin.king@canonical.comSigned-off-by: Ingo Molnar <mingo@kernel.org>

Merge tag 'perf-core-for-mingo-20160516' 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:

- Honour the kernel.perf_event_max_stack knob more precisely by not counting
  PERF_CONTEXT_{KERNEL,USER} when deciding when to stop adding entries to
  the perf_sample->ip_callchain[] array (Arnaldo Carvalho de Melo)

- Fix identation of 'stalled-backend-cycles' in 'perf stat' (Namhyung Kim)

- Update runtime using 'cpu-clock' event in 'perf stat' (Namhyung Kim)

- Use 'cpu-clock' for cpu targets in 'perf stat' (Namhyung Kim)

- Avoid fractional digits for integer scales in 'perf stat' (Andi Kleen)

- Store vdso buildid unconditionally, as it appears in callchains and
  we're not checking those when creating the build-id table, so we
  end up not being able to resolve VDSO symbols when doing analysis
  on a different machine than the one where recording was done, possibly
  of a different arch even (arm -> x86_64) (He Kuang)

Infrastructure changes:

- Generalize max_stack sysctl handler, will be used for configuring
  multiple kernel knobs related to callchains (Arnaldo Carvalho de Melo)

Cleanups:

- Introduce DSO__NAME_KALLSYMS and DSO__NAME_KCORE, to stop using
  open coded strings (Masami Hiramatsu)
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

The move of the x86 perf implementation forgot to update the MAINTAINERS
F(ile) pattern.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Borislav Petkov <bp@suse.de>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: fa9cbf32 ("perf/x86: Move perf_event.c ............... => x86/events/core.c")
Link: http://lkml.kernel.org/r/20160519103019.GJ3206@twins.programming.kicks-ass.netSigned-off-by: Ingo Molnar <mingo@kernel.org>

When booting with nr_cpus=1, uncore_pci_probe tries to init the PCI/uncore
also for the other packages and fails with warning when they are not found.

The warning is bogus because it's correct to fail here for packages which are
not initialized. Remove it and return silently.

Fixes: cf6d445f "perf/x86/uncore: Track packages, not per CPU data"
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: stable@vger.kernel.org
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

The perf_sample->ip_callchain->nr value includes all the entries in the
ip_callchain->ip[] array, real addresses and PERF_CONTEXT_{KERNEL,USER,etc},
while what the user expects is that what is in the kernel.perf_event_max_stack
sysctl or in the upcoming per event perf_event_attr.sample_max_stack knob be
honoured in terms of IP addresses in the stack trace.

So match the kernel support and validate chain->nr taking into account
both kernel.perf_event_max_stack and kernel.perf_event_max_contexts_per_stack.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jiri Olsa <jolsa@redhat.com>
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/n/tip-mgx0jpzfdq4uq4abfa40byu0@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

The perf_sample->ip_callchain->nr value includes all the entries in the
ip_callchain->ip[] array, real addresses and PERF_CONTEXT_{KERNEL,USER,etc},
while what the user expects is that what is in the kernel.perf_event_max_stack
sysctl or in the upcoming per event perf_event_attr.sample_max_stack knob be
honoured in terms of IP addresses in the stack trace.

So allocate a bunch of extra entries for contexts, and do the accounting
via perf_callchain_entry_ctx struct members.

A new sysctl, kernel.perf_event_max_contexts_per_stack is also
introduced for investigating possible bugs in the callchain
implementation by some arch.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jiri Olsa <jolsa@redhat.com>
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/n/tip-3b4wnqk340c4sg4gwkfdi9yk@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

We need have different helpers to account how many contexts we have in
the sample and for real addresses, so do it now as a prep patch, to
ease review.

Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/n/tip-q964tnyuqrxw5gld18vizs3c@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

We will use it to count how many addresses are in the entry->ip[] array,
excluding PERF_CONTEXT_{KERNEL,USER,etc} entries, so that we can really
return the number of entries specified by the user via the relevant
sysctl, kernel.perf_event_max_contexts, or via the per event
perf_event_attr.sample_max_stack knob.

This way we keep the perf_sample->ip_callchain->nr meaning, that is the
number of entries, be it real addresses or PERF_CONTEXT_ entries, while
honouring the max_stack knobs, i.e. the end result will be max_stack
entries if we have at least that many entries in a given stack trace.

Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/n/tip-s8teto51tdqvlfhefndtat9r@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

This makes perf_callchain_{user,kernel}() receive the max stack
as context for the perf_callchain_entry, instead of accessing
the global sysctl_perf_event_max_stack.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.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/n/tip-kolmn1yo40p7jhswxwrc7rrd@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

So that it can be used for other stack related knobs, such as the
upcoming one to tweak the max number of of contexts per stack sample.

In all those cases we can only change the value if there are no perf
sessions collecting stacks, so they need to grab that mutex, etc.

Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/n/tip-8t3fk94wuzp8m2z1n4gc0s17@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Instead of using a raw string, use DSO__NAME_KALLSYMS and
DSO__NAME_KCORE macros for kallsyms and kcore.
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.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/20160515031935.4017.50971.stgit@devboxSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Currently 'perf stat' always counts task-clock event by default.  But
it's somewhat confusing for system-wide targets (especially with 'sleep
N' as the 'sleep' task just sleeps and doesn't use cputime).  Changing
to cpu-clock event instead for that case makes more sense IMHO.

Before:
  # perf stat -a sleep 0.1

   Performance counter stats for 'system wide':

        403.038603      task-clock (msec)     #    4.001 CPUs utilized
               150      context-switches      #    0.372 K/sec
                 7      cpu-migrations        #    0.017 K/sec
                71      page-faults           #    0.176 K/sec
        23,705,169      cycles                #    0.059 GHz
        15,888,166      instructions          #    0.67  insn per cycle
         3,326,078      branches              #    8.253 M/sec
            87,643      branch-misses         #    2.64% of all branches

       0.100737009 seconds time elapsed

  #

After:

  # perf stat -a sleep 0.1

   Performance counter stats for 'system wide':

        404.271182      cpu-clock (msec)      #    4.000 CPUs utilized
               143      context-switches      #    0.354 K/sec
                13      cpu-migrations        #    0.032 K/sec
                73      page-faults           #    0.181 K/sec
        22,119,220      cycles                #    0.055 GHz
        13,622,065      instructions          #    0.62  insn per cycle
         2,918,769      branches              #    7.220 M/sec
            85,033      branch-misses         #    2.91% of all branches

       0.101073089 seconds time elapsed

  #
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1463119263-5569-3-git-send-email-namhyung@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Currently only the task-clock event updates the runtime_nsec so it
cannot show the metric when using cpu-clock events.  However cpu clock
works basically same as task-clock, so no need to not update the runtime
IMHO.

Before:

  # perf stat -a -e cpu-clock,context-switches,page-faults,cycles sleep 0.1

    Performance counter stats for 'system wide':

         1217.759506      cpu-clock (msec)
                  93      context-switches
                  61      page-faults
          18,958,022      cycles

         0.101393794 seconds time elapsed

After:

   Performance counter stats for 'system wide':

         1220.471884      cpu-clock (msec)          #   12.013 CPUs utilized
                 118      context-switches          #    0.097 K/sec
                  59      page-faults               #    0.048 K/sec
          17,941,247      cycles                    #    0.015 GHz

         0.101594777 seconds time elapsed
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1463119263-5569-2-git-send-email-namhyung@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

The commit 140aeadc ("perf stat: Abstract stat metrics printing")
changed how shadow metrics are printed, but it missed to update the
width of the stalled backend cycles event to 7.2% like others.  This
resulted in misaligned output like below:

  Performance counter stats for 'pwd':

          0.638313      task-clock (msec)         #    0.567 CPUs utilized
                 0      context-switches          #    0.000 K/sec
                 0      cpu-migrations            #    0.000 K/sec
                54      page-faults               #    0.085 M/sec
           885,600      cycles                    #    1.387 GHz
           558,438      stalled-cycles-frontend   #   63.06% frontend cycles idle
           431,355      stalled-cycles-backend    #  48.71% backend cycles idle
           674,956      instructions              #    0.76  insn per cycle
                                                  #    0.83  stalled cycles per insn
           130,380      branches                  #  204.257 M/sec
     <not counted>      branch-misses

       0.001125426 seconds time elapsed
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Fixes: 140aeadc ("perf stat: Abstract stat metrics printing")
Link: http://lkml.kernel.org/r/1463119263-5569-1-git-send-email-namhyung@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

When unwinding callchains on a different machine, vdso info should be
available so the unwind process won't be interrupted if address falls
into vdso region. But in most cases, the addresses of sample events are
not in vdso range, the buildid of a zero hit vdso won't be stored into
perf.data.

This patch stores vdso buildid regardless of whether the vdso is hit or
not.
Signed-off-by: He Kuang <hekuang@huawei.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Ekaterina Tumanova <tumanova@linux.vnet.ibm.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Kan Liang <kan.liang@intel.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/1463042596-61703-3-git-send-email-hekuang@huawei.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

When the scaling factor is a full integer don't display fractional
digits. This avoids unnecessary .00 output for topdown metrics with
scale factors.

v2: Remove redundant check.
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1462489447-31832-7-git-send-email-andi@firstfloor.org
[ Rename 'round' to 'stat_round' as 'round' is defined in math.h,
  included by this patch, and this breaks the build on ubuntu 12.04 ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Pull x86 platform updates from Ingo Molnar:
 "The main change is the addition of SGI/UV4 support"

* 'x86-platform-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (22 commits)
  x86/platform/UV: Fix incorrect nodes and pnodes for cpuless and memoryless nodes
  x86/platform/UV: Remove Obsolete GRU MMR address translation
  x86/platform/UV: Update physical address conversions for UV4
  x86/platform/UV: Build GAM reference tables
  x86/platform/UV: Support UV4 socket address changes
  x86/platform/UV: Add obtaining GAM Range Table from UV BIOS
  x86/platform/UV: Add UV4 addressing discovery function
  x86/platform/UV: Fold blade info into per node hub info structs
  x86/platform/UV: Allocate common per node hub info structs on local node
  x86/platform/UV: Move blade local processor ID to the per cpu info struct
  x86/platform/UV: Move scir info to the per cpu info struct
  x86/platform/UV: Create per cpu info structs to replace per hub info structs
  x86/platform/UV: Update MMIOH setup function to work for both UV3 and UV4
  x86/platform/UV: Clean up redunduncies after merge of UV4 MMR definitions
  x86/platform/UV: Add UV4 Specific MMR definitions
  x86/platform/UV: Prep for UV4 MMR updates
  x86/platform/UV: Add UV MMR Illegal Access Function
  x86/platform/UV: Add UV4 Specific Defines
  x86/platform/UV: Add UV Architecture Defines
  x86/platform/UV: Add Initial UV4 definitions
  ...

Pull x86 debug cleanup from Ingo Molnar:
 "A printk() output simplification"

* 'x86-debug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/dumpstack: Combine some printk()s

Pull x86 cleanup from Ingo Molnar:
 "Inline optimizations"

* 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86: Fix non-static inlines

Pull x86-64 defconfig update from Ingo Molnar:
 "Small defconfig addition"

[ I'm not actually convinced our defconfig is sensible, but whatever ]

* 'x86-build-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/build/defconfig/64: Enable CONFIG_E1000E=y

Pull x86 boot updates from Ingo Molnar:
 "The biggest changes in this cycle were:

   - prepare for more KASLR related changes, by restructuring, cleaning
     up and fixing the existing boot code.  (Kees Cook, Baoquan He,
     Yinghai Lu)

   - simplifly/concentrate subarch handling code, eliminate
     paravirt_enabled() usage.  (Luis R Rodriguez)"

* 'x86-boot-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (50 commits)
  x86/KASLR: Clarify purpose of each get_random_long()
  x86/KASLR: Add virtual address choosing function
  x86/KASLR: Return earliest overlap when avoiding regions
  x86/KASLR: Add 'struct slot_area' to manage random_addr slots
  x86/boot: Add missing file header comments
  x86/KASLR: Initialize mapping_info every time
  x86/boot: Comment what finalize_identity_maps() does
  x86/KASLR: Build identity mappings on demand
  x86/boot: Split out kernel_ident_mapping_init()
  x86/boot: Clean up indenting for asm/boot.h
  x86/KASLR: Improve comments around the mem_avoid[] logic
  x86/boot: Simplify pointer casting in choose_random_location()
  x86/KASLR: Consolidate mem_avoid[] entries
  x86/boot: Clean up pointer casting
  x86/boot: Warn on future overlapping memcpy() use
  x86/boot: Extract error reporting functions
  x86/boot: Correctly bounds-check relocations
  x86/KASLR: Clean up unused code from old 'run_size' and rename it to 'kernel_total_size'
  x86/boot: Fix "run_size" calculation
  x86/boot: Calculate decompression size during boot not build
  ...

Pull x86 asm updates from Ingo Molnar:
 "The main changes in this cycle were:

   - MSR access API fixes and enhancements (Andy Lutomirski)

   - early exception handling improvements (Andy Lutomirski)

   - user-space FS/GS prctl usage fixes and improvements (Andy
     Lutomirski)

   - Remove the cpu_has_*() APIs and replace them with equivalents
     (Borislav Petkov)

   - task switch micro-optimization (Brian Gerst)

   - 32-bit entry code simplification (Denys Vlasenko)

   - enhance PAT handling in enumated CPUs (Toshi Kani)

  ... and lots of other cleanups/fixlets"

* 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (70 commits)
  x86/arch_prctl/64: Restore accidentally removed put_cpu() in ARCH_SET_GS
  x86/entry/32: Remove asmlinkage_protect()
  x86/entry/32: Remove GET_THREAD_INFO() from entry code
  x86/entry, sched/x86: Don't save/restore EFLAGS on task switch
  x86/asm/entry/32: Simplify pushes of zeroed pt_regs->REGs
  selftests/x86/ldt_gdt: Test set_thread_area() deletion of an active segment
  x86/tls: Synchronize segment registers in set_thread_area()
  x86/asm/64: Rename thread_struct's fs and gs to fsbase and gsbase
  x86/arch_prctl/64: Remove FSBASE/GSBASE < 4G optimization
  x86/segments/64: When load_gs_index fails, clear the base
  x86/segments/64: When loadsegment(fs, ...) fails, clear the base
  x86/asm: Make asm/alternative.h safe from assembly
  x86/asm: Stop depending on ptrace.h in alternative.h
  x86/entry: Rename is_{ia32,x32}_task() to in_{ia32,x32}_syscall()
  x86/asm: Make sure verify_cpu() has a good stack
  x86/extable: Add a comment about early exception handlers
  x86/msr: Set the return value to zero when native_rdmsr_safe() fails
  x86/paravirt: Make "unsafe" MSR accesses unsafe even if PARAVIRT=y
  x86/paravirt: Add paravirt_{read,write}_msr()
  x86/msr: Carry on after a non-"safe" MSR access fails
  ...