linux/tools
Masami Hiramatsu 576b523721 perf probe: Fix probing symbols with optimization suffix
Fix perf probe to probe on some symbols which have some optimzation
suffixes, e.g. ".part", ".isra", and ".constprop".

To fix this issue, instead of using the DIE name, perf probe uses the
symbol name found by dwfl_module_addrsym().

This also involves a perf probe --vars operation update which now shows
the symbol name instead of the DIE name.

Without this patch, putting a probe on an inlined function which was
compiled with a suffixed symbol will fail like this:

  $ perf probe -v getname_flags
  probe-definition(0): getname_flags
  symbol:getname_flags file:(null) line:0 offset:0 return:0 lazy:(null)
  0 arguments
  Looking at the vmlinux_path (6 entries long)
  Using /lib/modules/3.11.0+/build/vmlinux for symbols
  found inline addr: 0xffffffff8119bb70
  Probe point found: getname_flags+0
  found inline addr: 0xffffffff8119bcb6
  Probe point found: getname+6
  found inline addr: 0xffffffff811a06a6
  Probe point found: user_path_at_empty+6
  find 3 probe_trace_events.
  Opening /sys/kernel/debug//tracing/kprobe_events write=1
  Added new events:
  Writing event: p:probe/getname_flags getname_flags+0
  Failed to write event: No such file or directory
    Error: Failed to add events. (-1)

Because the debuginfo knows only the original (non suffix) symbol name,
it uses the original symbol for probe address but the kernel (kallsyms)
knows only suffixed symbol.  Then, the kernel rejects that original
symbol.

This patch uses dwfl_module_addrsym() to get the correct (suffixed)
symbol from symtab when a probe point is found.

Reported-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20130925131616.31632.46658.stgit@udc4-manage.rcp.hitachi.co.jp
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2013-09-25 12:27:31 -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 probing symbols with optimization suffix 2013-09-25 12:27:31 -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