[PATCH -perf/perf/core 1/6] perf probe: Introduce lines walker interface

Masami Hiramatsu
2011-01-13T12:51:35Z

Introduce die_walk_lines() for walking on the line list
of given die, and use it in line_range finder and probe
point finder.

Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Cc: linux-kernel@vger.kernel.org
---

tools/perf/util/probe-finder.c | 321 +++++++++++++++++++++-------------------
1 files changed, 167 insertions(+), 154 deletions(-)

diff --git a/tools/perf/util/probe-finder.c b/tools/perf/util/probe-finder.c
index ab83b6a..5926d25 100644
--- a/tools/perf/util/probe-finder.c
+++ b/tools/perf/util/probe-finder.c
@@ -458,6 +458,124 @@ static Dwarf_Die *die_find_inlinefunc(Dwarf_Die *sp_die, Dwarf_Addr addr,
return die_find_child(sp_die, __die_find_inline_cb, &addr, die_mem);
}

+/* Walker on lines (Note: line number will not be sorted) */
+typedef int (* line_walk_handler_t) (const char *fname, int lineno,
+ Dwarf_Addr addr, void *data);
+
+struct __line_walk_param {
+ line_walk_handler_t handler;
+ void *data;
+ int retval;
+};
+
+/* Walk on decl lines in given DIE */
+static int __die_walk_funclines(Dwarf_Die *sp_die,
+ line_walk_handler_t handler, void *data)
+{
+ const char *fname;
+ Dwarf_Addr addr;
+ int lineno, ret = 0;
+
+ /* Handle function declaration line */
+ fname = dwarf_decl_file(sp_die);
+ if (fname && dwarf_decl_line(sp_die, &lineno) == 0 &&
+ dwarf_entrypc(sp_die, &addr) == 0) {
+ ret = handler(fname, lineno, addr, data);
+ }
+
+ return ret;
+}
+
+static int __die_walk_culines_cb(Dwarf_Die *sp_die, void *data)
+{
+ struct __line_walk_param *lw = data;
+
+ lw->retval = __die_walk_funclines(sp_die, lw->handler, lw->data);
+ if (lw->retval != 0)
+ return DWARF_CB_ABORT;
+
+ return DWARF_CB_OK;
+}
+
+/*
+ * Walk on lines inside given PDIE. If the PDIE is subprogram, walk only on
+ * the lines inside the subprogram, otherwise PDIE must be a CU DIE.
+ */
+static int die_walk_lines(Dwarf_Die *pdie, line_walk_handler_t handler,
+ void *data)
+{
+ Dwarf_Lines *lines;
+ Dwarf_Line *line;
+ Dwarf_Addr addr;
+ const char *fname;
+ int lineno, ret = 0;
+ Dwarf_Die die_mem, *cu_die;
+ size_t nlines, i;
+
+ /* Get the CU die */
+ if (dwarf_tag(pdie) == DW_TAG_subprogram)
+ cu_die = dwarf_diecu(pdie, &die_mem, NULL, NULL);
+ else
+ cu_die = pdie;
+ if (!cu_die) {
+ pr_debug2("Failed to get CU from subprogram\n");
+ return -EINVAL;
+ }
+
+ /* Get lines list in the CU */
+ if (dwarf_getsrclines(cu_die, &lines, &nlines) != 0) {
+ pr_debug2("Failed to get source lines on this CU.\n");
+ return -ENOENT;
+ }
+ pr_debug2("Get %ld lines from this CU\n", nlines);
+
+ /* Walk on the lines on lines list */
+ for (i = 0; i < nlines; i++) {
+ line = dwarf_onesrcline(lines, i);
+ if (line == NULL ||
+ dwarf_lineno(line, &lineno) != 0 ||
+ dwarf_lineaddr(line, &addr) != 0) {
+ pr_debug2("Failed to get line info. "
+ "Possible error in debuginfo.\n");
+ continue;
+ }
+ /* Filter lines based on address */
+ if (pdie != cu_die)
+ /*
+ * Address filtering
+ * The line is included in given function, and
+ * no inline block includes it.
+ */
+ if (!dwarf_haspc(pdie, addr) ||
+ die_find_inlinefunc(pdie, addr, &die_mem))
+ continue;
+ /* Get source line */
+ fname = dwarf_linesrc(line, NULL, NULL);
+
+ ret = handler(fname, lineno, addr, data);
+ if (ret != 0)
+ return ret;
+ }
+
+ /*
+ * Dwarf lines doesn't include function declarations and inlined
+ * subroutines. We have to check functions list or given function.
+ */
+ if (pdie != cu_die)
+ ret = __die_walk_funclines(pdie, handler, data);
+ else {
+ struct __line_walk_param param = {
+ .handler = handler,
+ .data = data,
+ .retval = 0,
+ };
+ dwarf_getfuncs(cu_die, __die_walk_culines_cb, &param, 0);
+ ret = param.retval;
+ }
+
+ return ret;
+}
+
struct __find_variable_param {
const char *name;
Dwarf_Addr addr;
@@ -1050,43 +1168,26 @@ static int call_probe_finder(Dwarf_Die *sp_die, struct probe_finder *pf)
return ret;
}

-/* Find probe point from its line number */
-static int find_probe_point_by_line(struct probe_finder *pf)
+static int probe_point_line_walker(const char *fname, int lineno,
+ Dwarf_Addr addr, void *data)
{
- Dwarf_Lines *lines;
- Dwarf_Line *line;
- size_t nlines, i;
- Dwarf_Addr addr;
- int lineno;
- int ret = 0;
+ struct probe_finder *pf = data;
+ int ret;

- if (dwarf_getsrclines(&pf->cu_die, &lines, &nlines) != 0) {
- pr_warning("No source lines found.\n");
- return -ENOENT;
- }
+ if (lineno != pf->lno || strtailcmp(fname, pf->fname) != 0)
+ return 0;

- for (i = 0; i < nlines && ret == 0; i++) {
- line = dwarf_onesrcline(lines, i);
- if (dwarf_lineno(line, &lineno) != 0 ||
- lineno != pf->lno)
- continue;
+ pf->addr = addr;
+ ret = call_probe_finder(NULL, pf);

- /* TODO: Get fileno from line, but how? */
- if (strtailcmp(dwarf_linesrc(line, NULL, NULL), pf->fname) != 0)
- continue;
-
- if (dwarf_lineaddr(line, &addr) != 0) {
- pr_warning("Failed to get the address of the line.\n");
- return -ENOENT;
- }
- pr_debug("Probe line found: line[%d]:%d addr:0x%jx\n",
- (int)i, lineno, (uintmax_t)addr);
- pf->addr = addr;
+ /* Continue if no error, because the line will be in inline function */
+ return ret < 0 ?: 0;
+}

- ret = call_probe_finder(NULL, pf);
- /* Continuing, because target line might be inlined. */
- }
- return ret;
+/* Find probe point from its line number */
+static int find_probe_point_by_line(struct probe_finder *pf)
+{
+ return die_walk_lines(&pf->cu_die, probe_point_line_walker, pf);
}

/* Find lines which match lazy pattern */
@@ -1140,15 +1241,31 @@ out_close:
return nlines;
}

+static int probe_point_lazy_walker(const char *fname, int lineno,
+ Dwarf_Addr addr, void *data)
+{
+ struct probe_finder *pf = data;
+ int ret;
+
+ if (!line_list__has_line(&pf->lcache, lineno) ||
+ strtailcmp(fname, pf->fname) != 0)
+ return 0;
+
+ pr_debug("Probe line found: line:%d addr:0x%llx\n",
+ lineno, (unsigned long long)addr);
+ pf->addr = addr;
+ ret = call_probe_finder(NULL, pf);
+
+ /*
+ * Continue if no error, because the lazy pattern will match
+ * to other lines
+ */
+ return ret < 0 ?: 0;
+}
+
/* Find probe points from lazy pattern */
static int find_probe_point_lazy(Dwarf_Die *sp_die, struct probe_finder *pf)
{
- Dwarf_Lines *lines;
- Dwarf_Line *line;
- size_t nlines, i;
- Dwarf_Addr addr;
- Dwarf_Die die_mem;
- int lineno;
int ret = 0;

if (list_empty(&pf->lcache)) {
@@ -1162,45 +1279,7 @@ static int find_probe_point_lazy(Dwarf_Die *sp_die, struct probe_finder *pf)
return ret;
}

- if (dwarf_getsrclines(&pf->cu_die, &lines, &nlines) != 0) {
- pr_warning("No source lines found.\n");
- return -ENOENT;
- }
-
- for (i = 0; i < nlines && ret >= 0; i++) {
- line = dwarf_onesrcline(lines, i);
-
- if (dwarf_lineno(line, &lineno) != 0 ||
- !line_list__has_line(&pf->lcache, lineno))
- continue;
-
- /* TODO: Get fileno from line, but how? */
- if (strtailcmp(dwarf_linesrc(line, NULL, NULL), pf->fname) != 0)
- continue;
-
- if (dwarf_lineaddr(line, &addr) != 0) {
- pr_debug("Failed to get the address of line %d.\n",
- lineno);
- continue;
- }
- if (sp_die) {
- /* Address filtering 1: does sp_die include addr? */
- if (!dwarf_haspc(sp_die, addr))
- continue;
- /* Address filtering 2: No child include addr? */
- if (die_find_inlinefunc(sp_die, addr, &die_mem))
- continue;
- }
-
- pr_debug("Probe line found: line[%d]:%d addr:0x%llx\n",
- (int)i, lineno, (unsigned long long)addr);
- pf->addr = addr;
-
- ret = call_probe_finder(sp_die, pf);
- /* Continuing, because target line might be inlined. */
- }
- /* TODO: deallocate lines, but how? */
- return ret;
+ return die_walk_lines(sp_die, probe_point_lazy_walker, pf);
}

/* Callback parameter with return value */
@@ -1644,91 +1723,28 @@ static int line_range_add_line(const char *src, unsigned int lineno,
return line_list__add_line(&lr->line_list, lineno);
}

-/* Search function declaration lines */
-static int line_range_funcdecl_cb(Dwarf_Die *sp_die, void *data)
+static int line_range_walk_cb(const char *fname, int lineno,
+ Dwarf_Addr addr __used,
+ void *data)
{
- struct dwarf_callback_param *param = data;
- struct line_finder *lf = param->data;
- const char *src;
- int lineno;
-
- src = dwarf_decl_file(sp_die);
- if (src && strtailcmp(src, lf->fname) != 0)
- return DWARF_CB_OK;
+ struct line_finder *lf = data;

- if (dwarf_decl_line(sp_die, &lineno) != 0 ||
+ if ((strtailcmp(fname, lf->fname) != 0) ||
(lf->lno_s > lineno || lf->lno_e < lineno))
- return DWARF_CB_OK;
+ return 0;

- param->retval = line_range_add_line(src, lineno, lf->lr);
- if (param->retval < 0)
- return DWARF_CB_ABORT;
- return DWARF_CB_OK;
-}
+ if (line_range_add_line(fname, lineno, lf->lr) < 0)
+ return -EINVAL;

-static int find_line_range_func_decl_lines(struct line_finder *lf)
-{
- struct dwarf_callback_param param = {.data = (void *)lf, .retval = 0};
- dwarf_getfuncs(&lf->cu_die, line_range_funcdecl_cb, &param, 0);
- return param.retval;
+ return 0;
}

/* Find line range from its line number */
static int find_line_range_by_line(Dwarf_Die *sp_die, struct line_finder *lf)
{
- Dwarf_Lines *lines;
- Dwarf_Line *line;
- size_t nlines, i;
- Dwarf_Addr addr;
- int lineno, ret = 0;
- const char *src;
- Dwarf_Die die_mem;
-
- line_list__init(&lf->lr->line_list);
- if (dwarf_getsrclines(&lf->cu_die, &lines, &nlines) != 0) {
- pr_warning("No source lines found.\n");
- return -ENOENT;
- }
-
- /* Search probable lines on lines list */
- for (i = 0; i < nlines; i++) {
- line = dwarf_onesrcline(lines, i);
- if (dwarf_lineno(line, &lineno) != 0 ||
- (lf->lno_s > lineno || lf->lno_e < lineno))
- continue;
-
- if (sp_die) {
- /* Address filtering 1: does sp_die include addr? */
- if (dwarf_lineaddr(line, &addr) != 0 ||
- !dwarf_haspc(sp_die, addr))
- continue;
-
- /* Address filtering 2: No child include addr? */
- if (die_find_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;
-
- ret = line_range_add_line(src, lineno, lf->lr);
- if (ret < 0)
- return ret;
- }
+ int ret;

- /*
- * Dwarf lines doesn't include function declarations. We have to
- * check functions list or given function.
- */
- if (sp_die) {
- src = dwarf_decl_file(sp_die);
- if (src && dwarf_decl_line(sp_die, &lineno) == 0 &&
- (lf->lno_s <= lineno && lf->lno_e >= lineno))
- ret = line_range_add_line(src, lineno, lf->lr);
- } else
- ret = find_line_range_func_decl_lines(lf);
+ ret = die_walk_lines(sp_die ?: &lf->cu_die, line_range_walk_cb, lf);

/* Update status */
if (ret >= 0)
@@ -1758,9 +1774,6 @@ static int line_range_search_cb(Dwarf_Die *sp_die, void *data)
struct line_finder *lf = param->data;
struct line_range *lr = lf->lr;

- pr_debug("find (%llx) %s\n",
- (unsigned long long)dwarf_dieoffset(sp_die),
- dwarf_diename(sp_die));
if (dwarf_tag(sp_die) == DW_TAG_subprogram &&
die_compare_name(sp_die, lr->function)) {
lf->fname = dwarf_decl_file(sp_die);