Commit 75186a9b authored Aug 12, 2015 by Masami Hiramatsu Committed by Arnaldo Carvalho de Melo Aug 12, 2015

perf probe: Fix to show lines of sys_ functions correctly



"perf probe --lines sys_poll" shows only the first line of sys_poll,
because the SYSCALL_DEFINE macro:

  ----
  SYSCALL_DEFINE*(foo,...)
  {
    body;
  }
  ----

  is expanded as below (on debuginfo)

  ----

  static inline int SYSC_foo(...)
  {
    body;
  }
  int SyS_foo(...) <- is an alias of sys_foo.
  {
    return SYSC_foo(...);
  }
  ----

So, "perf probe --lines sys_foo" decodes SyS_foo function and it also skips
inlined functions(SYSC_foo) inside the target function because those functions
are usually defined somewhere else.

To fix this issue, this fix checks whether the inlined function is defined at
the same point of the target function, and if so, it doesn't skip the inline
function.

Reported-by: Arnaldo Carvalho de Melo <acme@kernel.org>
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>
Link: http://lkml.kernel.org/r/20150812012406.11811.94691.stgit@localhost.localdomain


Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

parent 63ab1749

tools/perf/util/dwarf-aux.c

+13 −5

Original line number	Diff line number	Diff line
		@@ -734,15 +734,18 @@ int die_walk_lines(Dwarf_Die rt_die, line_walk_callback_t callback, void data)
		Dwarf_Lines *lines;
		Dwarf_Line *line;
		Dwarf_Addr addr;
		const char *fname;
		const char fname, decf = NULL;
		int lineno, ret = 0;
		int decl = 0, inl;
		Dwarf_Die die_mem, *cu_die;
		size_t nlines, i;

		/* Get the CU die */
		if (dwarf_tag(rt_die) != DW_TAG_compile_unit)
		if (dwarf_tag(rt_die) != DW_TAG_compile_unit) {
		cu_die = dwarf_diecu(rt_die, &die_mem, NULL, NULL);
		else
		dwarf_decl_line(rt_die, &decl);
		decf = dwarf_decl_file(rt_die);
		} else
		cu_die = rt_die;
		if (!cu_die) {
		pr_debug2("Failed to get CU from given DIE.\n");
		@@ -773,9 +776,14 @@ int die_walk_lines(Dwarf_Die rt_die, line_walk_callback_t callback, void data)
		* The line is included in given function, and
		* no inline block includes it.
		*/
		if (!dwarf_haspc(rt_die, addr) \|\|
		die_find_inlinefunc(rt_die, addr, &die_mem))
		if (!dwarf_haspc(rt_die, addr))
		continue;
		if (die_find_inlinefunc(rt_die, addr, &die_mem)) {
		dwarf_decl_line(&die_mem, &inl);
		if (inl != decl \|\|
		decf != dwarf_decl_file(&die_mem))
		continue;
		}
		/* Get source line */
		fname = dwarf_linesrc(line, NULL, NULL);

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