Commit 161a26b0 authored by Masami Hiramatsu's avatar Masami Hiramatsu Committed by Ingo Molnar
Browse files

perf probe: Check function address range strictly in line finder 



Check (inlined) function address range strictly for
improving output of probe-able lines of inline functions.

Without this change, perf probe --line <function> sometimes
showed other inline function bodies too, because it didn't
filter out inlined functions.

Signed-off-by: default avatarMasami Hiramatsu <mhiramat@redhat.com>
Cc: systemtap <systemtap@sources.redhat.com>
Cc: DLE <dle-develop@lists.sourceforge.net>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: K.Prasad <prasad@linux.vnet.ibm.com>
Cc: Ulrich Drepper <drepper@redhat.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
LKML-Reference: <20100225133557.6725.20697.stgit@localhost6.localdomain6>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent e92b85e1

tools/perf/util/probe-finder.c

+53 −21
Original line number Diff line number Diff line
@@ -161,6 +161,31 @@ static Dwarf_Die *die_get_real_subprogram(Dwarf_Die *cu_die, Dwarf_Addr addr, 
		return die_mem;

}



/* Similar to dwarf_getfuncs, but returns inlined_subroutine if exists. */

static Dwarf_Die *die_get_inlinefunc(Dwarf_Die *sp_die, Dwarf_Addr addr,

				     Dwarf_Die *die_mem)

{

	Dwarf_Die child_die;

	int ret;



	ret = dwarf_child(sp_die, die_mem);

	if (ret != 0)

		return NULL;



	do {

		if (dwarf_tag(die_mem) == DW_TAG_inlined_subroutine &&

		    dwarf_haspc(die_mem, addr))

			return die_mem;



		if (die_get_inlinefunc(die_mem, addr, &child_die)) {

			memcpy(die_mem, &child_die, sizeof(Dwarf_Die));

			return die_mem;

		}

	} while (dwarf_siblingof(die_mem, die_mem) == 0);



	return NULL;

}



/* Compare diename and tname */

static bool die_compare_name(Dwarf_Die *dw_die, const char *tname)

{
@@ -534,7 +559,7 @@ found: 
}



/* Find line range from its line number */

static void find_line_range_by_line(struct line_finder *lf)

static void find_line_range_by_line(Dwarf_Die *sp_die, struct line_finder *lf)

{

	Dwarf_Lines *lines;

	Dwarf_Line *line;
@@ -543,6 +568,7 @@ static void find_line_range_by_line(struct line_finder *lf) 
	int lineno;

	int ret;

	const char *src;

	Dwarf_Die die_mem;



	INIT_LIST_HEAD(&lf->lr->line_list);

	ret = dwarf_getsrclines(&lf->cu_die, &lines, &nlines);
@@ -550,22 +576,28 @@ static void find_line_range_by_line(struct line_finder *lf) 


	for (i = 0; i < nlines; i++) {

		line = dwarf_onesrcline(lines, i);

		dwarf_lineno(line, &lineno);

		ret = dwarf_lineno(line, &lineno);

		DIE_IF(ret != 0);

		if (lf->lno_s > lineno || lf->lno_e < lineno)

			continue;



		if (sp_die) {

			/* Address filtering 1: does sp_die include addr? */

			ret = dwarf_lineaddr(line, &addr);

			DIE_IF(ret != 0);

			if (!dwarf_haspc(sp_die, addr))

				continue;



			/* Address filtering 2: No child include addr? */

			if (die_get_inlinefunc(sp_die, addr, &die_mem))

				continue;

		}



		/* TODO: Get fileno from line, but how? */

		src = dwarf_linesrc(line, NULL, NULL);

		if (strtailcmp(src, lf->fname) != 0)

			continue;



		/* Filter line in the function address range */

		if (lf->addr_s && lf->addr_e) {

			ret = dwarf_lineaddr(line, &addr);

			DIE_IF(ret != 0);

			if (lf->addr_s > addr || lf->addr_e <= addr)

				continue;

		}

		/* Copy real path */

		if (!lf->lr->path)

			lf->lr->path = strdup(src);
@@ -580,24 +612,20 @@ static void find_line_range_by_line(struct line_finder *lf) 
	}

}



static int line_range_inline_cb(Dwarf_Die *in_die, void *data)

{

	find_line_range_by_line(in_die, (struct line_finder *)data);

	return DWARF_CB_ABORT;	/* No need to find other instances */

}



/* Search function from function name */

static int line_range_search_cb(Dwarf_Die *sp_die, void *data)

{

	struct line_finder *lf = (struct line_finder *)data;

	struct line_range *lr = lf->lr;

	int ret;



	if (dwarf_tag(sp_die) == DW_TAG_subprogram &&

	    die_compare_name(sp_die, lr->function) == 0) {

		/* Get the address range of this function */

		ret = dwarf_highpc(sp_die, &lf->addr_e);

		if (ret == 0)

			ret = dwarf_lowpc(sp_die, &lf->addr_s);

		if (ret != 0) {

			lf->addr_s = 0;

			lf->addr_e = 0;

		}



		lf->fname = dwarf_decl_file(sp_die);

		dwarf_decl_line(sp_die, &lr->offset);

		pr_debug("fname: %s, lineno:%d\n", lf->fname, lr->offset);
@@ -608,7 +636,11 @@ static int line_range_search_cb(Dwarf_Die *sp_die, void *data) 
			lf->lno_e = lr->offset + lr->end;

		lr->start = lf->lno_s;

		lr->end = lf->lno_e;

		find_line_range_by_line(lf);

		if (dwarf_func_inline(sp_die))

			dwarf_func_inline_instances(sp_die,

						    line_range_inline_cb, lf);

		else

			find_line_range_by_line(sp_die, lf);

		return 1;

	}

	return 0;
@@ -660,7 +692,7 @@ int find_line_range(int fd, struct line_range *lr) 
					lf.lno_e = INT_MAX;

				else

					lf.lno_e = lr->end;

				find_line_range_by_line(&lf);

				find_line_range_by_line(NULL, &lf);

			}

		}

		off = noff;

tools/perf/util/probe-finder.h

+0 −2
Original line number Diff line number Diff line
@@ -82,8 +82,6 @@ struct line_finder { 
	const char		*fname;		/* File name */

	int			lno_s;		/* Start line number */

	int			lno_e;		/* End line number */

	Dwarf_Addr		addr_s;		/* Start address */

	Dwarf_Addr		addr_e;		/* End address */

	Dwarf_Die		cu_die;		/* Current CU */

	int			found;

};

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