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: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Tested-by: Arnaldo 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: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Masami Hiramatsu 2015-03-06 16:31:22 +09:00 committed by Arnaldo Carvalho de Melo
parent 9b118acae3
commit 811dd2ae7c

View File

@ -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;