linux/tools
Masami Hiramatsu e08cfd4bda perf probe: Fix to find line information for probe list
Fix to find the correct (as much as possible) line information for
listing probes. Without this fix, perf probe --list action will show
incorrect line information as below;

  probe:getname_flags  (on getname_flags@ksrc/linux-3/fs/namei.c)
  probe:getname_flags_1 (on getname:-89@x86/include/asm/current.h)
  probe:getname_flags_2 (on user_path_at_empty:-2054@x86/include/asm/current.h)

The minus line number is obviously wrong, and current.h is not related
to the probe point. Deeper investigation discovered that there were 2
issues related to this bug, and minor typos too.

The 1st issue is the rack of considering about nested inlined functions,
which causes the wrong (relative) line number.

The 2nd issue is that the dwarf line info is not correct at those
points. It points 14th line of current.h.

Since it seems that the line info includes somewhat unreliable
information, this fixes perf to try to find correct line information
from both of debuginfo and line info as below.

1) Probe address is the entry of a function instance

  In this case, the line is set as the function declared line.

2) Probe address is the entry of an expanded inline function block

  In this case, the line is set as the function call-site line.
  This means that the line number is relative from the entry line
  of caller function (which can be an inlined function if nested)

3) Probe address is inside a function instance or an expanded
   inline function block

  In this case, perf probe queries the line number from lineinfo
  and verify the function declared file is same as the file name
  queried from lineinfo.

  If the file name is different, it is a failure case. The probe
  address is shown as symbol+offset.

4) Probe address is not in the any function instance

  This is a failure case, the probe address is shown as
  symbol+offset.

With this fix, perf probe -l shows correct probe lines as below;

  probe:getname_flags  (on getname_flags@ksrc/linux-3/fs/namei.c)
  probe:getname_flags_1 (on getname:2@ksrc/linux-3/fs/namei.c)
  probe:getname_flags_2 (on user_path_at_empty:4@ksrc/linux-3/fs/namei.c)

Changes at v2:
 - Fix typos in the function comments. (Thanks to Namhyung Kim)
 - Use die_find_top_inlinefunc instead of die_find_inlinefunc_next.

Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20130930092144.1693.11058.stgit@udc4-manage.rcp.hitachi.co.jp
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2013-10-04 15:16:05 -03:00
..
cgroup cgroups: fix cgroup_event_listener error handling 2013-01-08 10:00:44 -08:00
firewire tools/firewire: nosy-dump: check for allocation failure 2012-12-02 20:10:18 +01:00
hv Tools: hv: use full nlmsghdr in netlink_send 2013-08-12 15:44:57 -07:00
include/tools tools/include: use stdint types for user-space byteshift headers 2013-07-03 16:02:28 +02:00
lguest tools/lguest: offer VIRTIO_F_ANY_LAYOUT for net device. 2013-07-15 11:18:32 +09:30
lib tools lib lk: Uninclude linux/magic.h in debugfs.c 2013-09-19 15:08:53 -03:00
net filter: add minimal BPF JIT image disassembler 2013-03-21 11:35:41 -04:00
nfsd NFSD: Added fault injection script 2011-11-07 21:10:47 -05:00
perf perf probe: Fix to find line information for probe list 2013-10-04 15:16:05 -03:00
power cpupower: Add Haswell family 0x45 specific idle monitor to show PC8,9,10 states 2013-07-05 01:52:19 +02:00
scripts tools: Get only verbose output with V=1 2013-07-08 17:31:34 -03:00
testing selftests: Add test of PMU instruction counting on powerpc 2013-08-14 14:57:10 +10:00
usb tools: usb: ffs-test: Fix build failure 2013-03-07 12:23:17 +08:00
virtio virtio tools: add .gitignore 2013-07-15 11:18:31 +09:30
vm tools/vm: Switch to liblk library 2013-03-15 13:06:01 -03:00
Makefile Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2013-05-01 14:08:52 -07:00