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perf probe: Allow weak symbols to be probed 

It currently prevents adding probes in weak symbols.  But there're cases
that given name is an only weak symbol so that we cannot add probe.

  $ perf probe -x /usr/lib/libc.so.6 -a calloc
  Failed to find symbol calloc in /usr/lib/libc-2.21.so
    Error: Failed to add events.

  $ nm /usr/lib/libc.so.6 | grep calloc
  000000000007b1f0 t __calloc
  000000000007b1f0 T __libc_calloc
  000000000007b1f0 W calloc

This change will result in duplicate probes when strong and weak symbols
co-exist in a binary.  But I think it's not a big problem since probes
at the weak symbol will never be hit anyway.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Naohiro Aota <naota@elisp.net>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20150306073129.6904.41078.stgit@localhost.localdomain
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Namhyung Kim 2015-03-06 16:31:29 +09:00 committed by Arnaldo Carvalho de Melo
parent 680d926a8c
commit e578da3b20
1 changed files with 4 additions and 8 deletions
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12
tools/perf/util/probe-event.c
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@ -310,10 +310,8 @@ static int find_alternative_probe_point(struct debuginfo *dinfo,
/* Find the address of given function */
map__for_each_symbol_by_name(map, pp->function, sym) {
if (sym->binding == STB_GLOBAL || sym->binding == STB_LOCAL) {
address = sym->start;
break;
}
address = sym->start;
break;
}
if (!address) {
ret = -ENOENT;
@ -2485,8 +2483,7 @@ static int find_probe_functions(struct map *map, char *name)
struct symbol *sym;
map__for_each_symbol_by_name(map, name, sym) {
if (sym->binding == STB_GLOBAL || sym->binding == STB_LOCAL)
found++;
found++;
}
return found;
@ -2846,8 +2843,7 @@ static struct strfilter *available_func_filter;
static int filter_available_functions(struct map *map __maybe_unused,
struct symbol *sym)
{
if ((sym->binding == STB_GLOBAL || sym->binding == STB_LOCAL) &&
strfilter__compare(available_func_filter, sym->name))
if (strfilter__compare(available_func_filter, sym->name))
return 0;
return 1;
}