perf maps: Lookup maps in both intitial mountns and inner mountns.

If a process is in a mountns and has symbols in /tmp/perf-<pid>.map,
look first in the namespace using the tgid for the pidns that the
process might be in.  If the map isn't found there, try looking in the
mountns where perf is running, and use the tgid that's appropriate for
perf's pid namespace.  If all else fails, use the original pid.

This allows us to locate a symbol map file in the mount namespace, if it
was generated there.  However, we also try the tool's /tmp in case it's
there instead.

Signed-off-by: Krister Johansen <kjlx@templeofstupid.com>
Tested-by: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas-Mich Richter <tmricht@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/1499305693-1599-3-git-send-email-kjlx@templeofstupid.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c
index 2e9eb6aa3ce2..246b441110a1 100644
--- a/tools/perf/util/machine.c
+++ b/tools/perf/util/machine.c
@@ -1392,7 +1392,7 @@ int machine__process_mmap2_event(struct machine *machine,
 
         map = map__new(machine, event->mmap2.start,
                         event->mmap2.len, event->mmap2.pgoff,
-                        event->mmap2.pid, event->mmap2.maj,
+                        event->mmap2.maj,
                         event->mmap2.min, event->mmap2.ino,
                         event->mmap2.ino_generation,
                         event->mmap2.prot,
@@ -1450,7 +1450,7 @@ int machine__process_mmap_event(struct machine *machine, union perf_event *event
 
         map = map__new(machine, event->mmap.start,
                         event->mmap.len, event->mmap.pgoff,
-                        event->mmap.pid, 0, 0, 0, 0, 0, 0,
+                        0, 0, 0, 0, 0, 0,
                         event->mmap.filename,
                         type, thread);