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Commit 811dd2ae authored by Masami Hiramatsu's avatar Masami Hiramatsu Committed by Arnaldo Carvalho de Melo
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perf probe: Fix --line to handle aliased symbols in glibc 



Fix perf probe --line to handle aliased symbols correctly in glibc.

This makes line_range search failing back to address-based alternative
search as same as --add and --vars.

Without this patch;
  -----
  # ./perf probe -x /usr/lib64/libc-2.17.so -L malloc
  Specified source line is not found.
    Error: Failed to show lines.
  -----

With this patch;
  -----
  # ./perf probe -x /usr/lib64/libc-2.17.so -L malloc
  <__libc_malloc@/usr/src/debug/glibc-2.17-c758a686/malloc/malloc.c:0>
        0  __libc_malloc(size_t bytes)
        1  {
             mstate ar_ptr;
             void *victim;

             __malloc_ptr_t (*hook) (size_t, const __malloc_ptr_t)
        6      = force_reg (__malloc_hook);
        7    if (__builtin_expect (hook != NULL, 0))
        8      return (*hook)(bytes, RETURN_ADDRESS (0));

       10    arena_lookup(ar_ptr);

       12    arena_lock(ar_ptr, bytes);
  -----

Note that this actually shows __libc_malloc, since it is the real
instance of malloc. User can use both __libc_malloc and malloc for
--line.

Signed-off-by: default avatarMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Tested-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Naohiro Aota <naota@elisp.net>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20150306073122.6904.18540.stgit@localhost.localdomain


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 9b118aca

tools/perf/util/probe-event.c

+33 −2
Original line number Diff line number Diff line
@@ -353,6 +353,31 @@ static int get_alternative_probe_event(struct debuginfo *dinfo, 
	return ret;

}



static int get_alternative_line_range(struct debuginfo *dinfo,

				      struct line_range *lr,

				      const char *target, bool user)

{

	struct perf_probe_point pp = { 0 }, result = { 0 };

	int ret, len = 0;



	pp.function = lr->function;

	pp.file = lr->file;

	pp.line = lr->start;

	if (lr->end != INT_MAX)

		len = lr->end - lr->start;

	ret = find_alternative_probe_point(dinfo, &pp, &result,

					   target, user);

	if (!ret) {

		lr->function = result.function;

		lr->file = result.file;

		lr->start = result.line;

		if (lr->end != INT_MAX)

			lr->end = lr->start + len;

		clear_perf_probe_point(&pp);

	}

	return ret;

}



/* Open new debuginfo of given module */

static struct debuginfo *open_debuginfo(const char *module, bool silent)

{
@@ -734,7 +759,8 @@ static int _show_one_line(FILE *fp, int l, bool skip, bool show_num) 
 * Show line-range always requires debuginfo to find source file and

 * line number.

 */

static int __show_line_range(struct line_range *lr, const char *module)

static int __show_line_range(struct line_range *lr, const char *module,

			     bool user)

{

	int l = 1;

	struct int_node *ln;
@@ -750,6 +776,11 @@ static int __show_line_range(struct line_range *lr, const char *module) 
		return -ENOENT;



	ret = debuginfo__find_line_range(dinfo, lr);

	if (!ret) {	/* Not found, retry with an alternative */

		ret = get_alternative_line_range(dinfo, lr, module, user);

		if (!ret)

			ret = debuginfo__find_line_range(dinfo, lr);

	}

	debuginfo__delete(dinfo);

	if (ret == 0 || ret == -ENOENT) {

		pr_warning("Specified source line is not found.\n");
@@ -819,7 +850,7 @@ int show_line_range(struct line_range *lr, const char *module, bool user) 
	ret = init_symbol_maps(user);

	if (ret < 0)

		return ret;

	ret = __show_line_range(lr, module);

	ret = __show_line_range(lr, module, user);

	exit_symbol_maps();



	return ret;