We were still using the pathname found on the MMAP event, that could not
be the one we used when recording, so use the build-id cache for that,
only falling back to use the pathname in the MMAP event if no build-ids
are available.

With this we now also are able to do secure, seamless offline annotation.

Example:

[root@doppio linux-2.6-tip]# perf report -g none -v 2> /dev/null | head -10
     8.12%     Xorg  /usr/lib64/libpixman-1.so.0.14.0       0x0000000000026d02 B [.] pixman_rasterize_edges
     4.68%  firefox  /usr/lib64/xulrunner-1.9.1/libxul.so   0x00000000005dbdba B [.] 0x000000005dbdba
     3.70%  swapper  /lib/modules/2.6.34-rc6/build/vmlinux  0xffffffff81022cea ! [k] read_hpet
     2.96%     init  /lib/modules/2.6.34-rc6/build/vmlinux  0xffffffff81022cea ! [k] read_hpet
     2.73%  swapper  /lib/modules/2.6.34-rc6/build/vmlinux  0xffffffff8100a738 ! [k] mwait_idle_with_hints
[root@doppio linux-2.6-tip]# perf annotate -v pixman_rasterize_edges 2>&1 | grep Executing
Executing: objdump --start-address=0x000000371ce26670 --stop-address=0x000000371ce2709f -dS /root/.debug/.build-id/bd/6ac5199137aaeb279f864717d8d061477466c1|grep -v /root/.debug/.build-id/bd/6ac5199137aaeb279f864717d8d061477466c1|expand
[root@doppio linux-2.6-tip]# perf buildid-list | grep libpixman-1.so.0.14.0
bd6ac5199137aaeb279f864717d8d061477466c1 /usr/lib64/libpixman-1.so.0.14.0
[root@doppio linux-2.6-tip]#
Reported-by: Stephane Eranian <eranian@google.com>
Cc: Frédéric Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stephane Eranian <eranian@google.com>
Cc: Tom Zanussi <tzanussi@gmail.com>
LKML-Reference: <new-submission>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>