When perf_event_attr.mmap_data is set the kernel will generate
PERF_RECORD_MMAP events when non-exec (data, SysV mem) mmaps are
created, so we need to synthesize from /proc/pid/maps for existing
threads, as we do for exec mmaps.

Right now just 'perf record' does it, but any other tool that uses
perf_event__synthesize_thread(s|map) can request it.
Reported-by: NDon Zickus <dzickus@redhat.com>
Tested-by: NDon Zickus <dzickus@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Bill Gray <bgray@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Joe Mario <jmario@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Richard Fowles <rfowles@redhat.com>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-ihwzraikx23ian9txinogvv2@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

This way we can later delimit a lifecycle for the COMM and map a hist to
a precise COMM:timeslice couple.

PERF_RECORD_COMM and PERF_RECORD_FORK events that don't have
PERF_SAMPLE_TIME samples can only send 0 value as a timestamp and thus
should overwrite any previous COMM on a given thread because there is no
sensible way to keep track of all the comms lifecycles in a thread
without time informations.
Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
Tested-by: NJiri Olsa <jolsa@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-6tyow99vgmmtt9qwr2u2lqd7@git.kernel.org
[ Made it cope with PERF_RECORD_MMAP2 ]
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

The tail position of the event buffer should only be modified after
actually use that event.

If not the event buffer could be invalid before use, and segment fault
occurs when invoking perf top -G.
Signed-off-by: NZhouyi Zhou <yizhouzhou@ict.ac.cn>
Cc: David Ahern <dsahern@gmail.com>
Cc: Zhouyi Zhou <yizhouzhou@ict.ac.cn>
Link: http://lkml.kernel.org/r/1382600613-32177-1-git-send-email-zhouzhouyi@gmail.com
[ Simplified the logic using exit gotos and renamed write_tail method to mmap_consume ]
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Add a new parameter for 'pid' to machine__findnew_thread().
Change callers to pass 'pid' when it is known.

Note that callers sometimes want to find the main thread
which has the memory maps.  The main thread has tid == pid
so the usage in that case is:

	machine__findnew_thread(machine, pid, pid)

whereas the usage to find the specific thread is:

	machine__findnew_thread(machine, pid, tid)
Signed-off-by: NAdrian Hunter <adrian.hunter@intel.com>
Acked-by: NDavid Ahern <dsahern@gmail.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1377591794-30553-2-git-send-email-adrian.hunter@intel.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Commit b55ae0a9 added code-reading.c which fails to compile on Fedora 16
with compiler version:
$ gcc --version
gcc (GCC) 4.6.3 20120306 (Red Hat 4.6.3-2)

Failure message is:

tests/code-reading.c: In function ‘do_sort_something’:
tests/code-reading.c:305:13: error: stack protector not protecting local variables: variable length buffer [-Werror=stack-protector]
cc1: all warnings being treated as errors
make: *** [/tmp/junk/tests/code-reading.o] Error 1
make: *** Waiting for unfinished jobs....

v2: as Adrian noticed changed sizeof to ARRAY_SIZE
Signed-off-by: NDavid Ahern <dsahern@gmail.com>
Acked-by: NAdrian Hunter <adrian.hunter@intel.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lkml.kernel.org/r/1376454732-83728-1-git-send-email-dsahern@gmail.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Now that the symbol filter is recorded on the machine there is no need
to pass it to thread__find_addr_map().  So remove it.
Signed-off-by: NAdrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1375961547-30267-9-git-send-email-adrian.hunter@intel.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Make the "object code reading" test attempt to read from kcore.

The test uses objdump which struggles with kcore. i.e.  doesn't always
work, sometimes takes a long time.  The test has been made to work
around those issues.
Signed-off-by: NAdrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1375875537-4509-10-git-send-email-adrian.hunter@intel.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

In order to use kernel maps to read object code, those maps must be
adjusted to map to the dso file offset.  Because lazy-initialization is
used, that is not done until symbols are loaded.  However the maps are
first used by thread__find_addr_map() before symbols are loaded.  So
this patch changes thread__find_addr() to "load" kernel maps before
using them.
Signed-off-by: NAdrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1375875537-4509-3-git-send-email-adrian.hunter@intel.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Using the information in mmap events, perf tools can read object code
associated with sampled addresses.  A test is added that compares bytes
read by perf with the same bytes read using objdump.
Signed-off-by: NAdrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1375875537-4509-2-git-send-email-adrian.hunter@intel.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>