In preparation for moving clockid validation into jit_process().

Previously a return value of zero meant the processing had been done and
non-zero meant either the processing was not done (i.e. not the jitdump
file mmap event) or an error occurred.

Change it so that zero means the processing was not done, one means the
processing was done and successful, and negative values are an error.
Signed-off-by: NAdrian Hunter <adrian.hunter@intel.com>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.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>
Link: http://lkml.kernel.org/r/1457005856-6143-5-git-send-email-adrian.hunter@intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

This patch adds source line information support to perf for jitted code.

The source line info must be emitted by the runtime, such as JVMTI.

Perf injects extract the source line info from the jitdump file and adds
the corresponding .debug_lines section in the ELF image generated for
each jitted function.

The source line enables matching any address in the profile with a
source file and line number.

The improvement is visible in perf annotate with the source code
displayed alongside the assembly code.

The dwarf code leverages the support from OProfile which is also
released under GPLv2.  Copyright 2007 OProfile authors.
Signed-off-by: NStephane Eranian <eranian@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Carl Love <cel@us.ibm.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: John McCutchan <johnmccutchan@google.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Pawel Moll <pawel.moll@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sonny Rao <sonnyrao@chromium.org>
Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/1448874143-7269-5-git-send-email-eranian@google.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

This patch adds a --jit/-j option to perf inject.

This options injects MMAP records into the perf.data file to cover the
jitted code mmaps. It also emits ELF images for each function in the
jidump file.  Those images are created where the jitdump file is.  The
MMAP records point to that location as well.

Typical flow:

  $ perf record -k mono -- java -agentpath:libpjvmti.so java_class
  $ perf inject --jit -i perf.data -o perf.data.jitted
  $ perf report -i perf.data.jitted

Note that jitdump.h support is not limited to Java, it works with any
jitted environment modified to emit the jitdump file format, include
those where code can be jitted multiple times and moved around.

The jitdump.h format is adapted from the Oprofile project.

The genelf.c (ELF binary generation) depends on MD5 hash encoding for
the buildid. To enable this, libssl-dev must be installed. If not, then
genelf.c defaults to using urandom to generate the buildid, which is not
ideal.  The Makefile auto-detects the presence on libssl-dev.

This version mmaps the jitdump file to create a marker MMAP record in
the perf.data file. The marker is used to detect jitdump and cause perf
inject to inject the jitted mmaps and generate ELF images for jitted
functions.

In V8, the following fixes and changes were made among other things:

  -  the jidump header format include a new flags field to be used
     to carry information about the configuration of the runtime agent.
     Contributed by: Adrian Hunter <adrian.hunter@intel.com>

  - Fix mmap pgoff: MMAP event pgoff must be the offset within the ELF file
    at which the code resides.
    Contributed by: Adrian Hunter <adrian.hunter@intel.com>

  - Fix ELF virtual addresses: perf tools expect the ELF virtual addresses of dynamic
    objects to match the file offset.
    Contributed by: Adrian Hunter <adrian.hunter@intel.com>

  - JIT MMAP injection does not obey finished_round semantics. JIT MMAP injection injects all
    MMAP events in one go, so it does not obey finished_round semantics, so drop the
    finished_round events from the output perf.data file.
    Contributed by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: NStephane Eranian <eranian@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Carl Love <cel@us.ibm.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: John McCutchan <johnmccutchan@google.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Pawel Moll <pawel.moll@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sonny Rao <sonnyrao@chromium.org>
Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/1448874143-7269-3-git-send-email-eranian@google.com
[ Moved inject.build_ids ordering bits to a separate patch, fixed the NO_LIBELF=1 build ]
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>