[PATCH v2 2/5] perf report: Find the inline stack for a given address

Jin Yao
2016-12-07T05:31:40Z

It would be useful for perf to support a mode to query the
inline stack for a given callgraph address. This would simplify
finding the right code in code that does a lot of inlining.

The srcline.c has contained the code which supports to translate
the address to filename:line_nr. This patch just extends the
function to let it support getting the inline stacks.

It introduces the inline_list which will store the inline
function result (format is filename:line_nr).

Signed-off-by: Jin Yao <yao.jin@linux.intel.com>
---
tools/perf/util/srcline.c | 139 ++++++++++++++++++++++++++++++++++++++++++++--
tools/perf/util/util.h | 14 +++++
2 files changed, 148 insertions(+), 5 deletions(-)

diff --git a/tools/perf/util/srcline.c b/tools/perf/util/srcline.c
index 2953c9f..84be07d 100644
--- a/tools/perf/util/srcline.c
+++ b/tools/perf/util/srcline.c
@@ -30,6 +30,22 @@ static const char *dso__name(struct dso *dso)
return dso_name;
}

+static int inline_list__append(char *filename, int line_nr,
+ struct inline_node *node)
+{
+ struct inline_list *ilist;
+
+ ilist = zalloc(sizeof(*ilist));
+ if (ilist == NULL)
+ return -1;
+
+ ilist->filename = filename;
+ ilist->line_nr = line_nr;
+ list_add_tail(&ilist->list, &node->val);
+
+ return 0;
+}
+
#ifdef HAVE_LIBBFD_SUPPORT

/*
@@ -171,7 +187,7 @@ static void addr2line_cleanup(struct a2l_data *a2l)

static int addr2line(const char *dso_name, u64 addr,
char **file, unsigned int *line, struct dso *dso,
- bool unwind_inlines)
+ bool unwind_inlines, struct inline_node *node)
{
int ret = 0;
struct a2l_data *a2l = dso->a2l;
@@ -196,8 +212,14 @@ static int addr2line(const char *dso_name, u64 addr,

while (bfd_find_inliner_info(a2l->abfd, &a2l->filename,
&a2l->funcname, &a2l->line) &&
- cnt++ < MAX_INLINE_NEST)
- ;
+ cnt++ < MAX_INLINE_NEST) {
+
+ if (node != NULL) {
+ if (inline_list__append(strdup(a2l->filename),
+ a2l->line, node) != 0)
+ return 0;
+ }
+ }
}

if (a2l->found && a2l->filename) {
@@ -223,6 +245,35 @@ void dso__free_a2l(struct dso *dso)
dso->a2l = NULL;
}

+static struct inline_node *addr2inlines(const char *dso_name, u64 addr,
+ struct dso *dso)
+{
+ char *file = NULL;
+ unsigned int line = 0;
+ struct inline_node *node;
+
+ node = zalloc(sizeof(*node));
+ if (node == NULL) {
+ perror("not enough memory for the inline node");
+ return NULL;
+ }
+
+ INIT_LIST_HEAD(&node->val);
+ node->addr = addr;
+
+ if (!addr2line(dso_name, addr, &file, &line, dso, TRUE, node)) {
+ inline_node__free(node);
+ return NULL;
+ }
+
+ if (list_empty(&node->val)) {
+ inline_node__free(node);
+ return NULL;
+ }
+
+ return node;
+}
+
#else /* HAVE_LIBBFD_SUPPORT */

static int filename_split(char *filename, unsigned int *line_nr)
@@ -249,7 +300,8 @@ static int filename_split(char *filename, unsigned int *line_nr)
static int addr2line(const char *dso_name, u64 addr,
char **file, unsigned int *line_nr,
struct dso *dso __maybe_unused,
- bool unwind_inlines __maybe_unused)
+ bool unwind_inlines __maybe_unused,
+ struct inline_node *node __maybe_unused)
{
FILE *fp;
char cmd[PATH_MAX];
@@ -288,6 +340,57 @@ void dso__free_a2l(struct dso *dso __maybe_unused)
{
}

+static struct inline_node *addr2inlines(const char *dso_name, u64 addr,
+ struct dso *dso __maybe_unused)
+{
+ FILE *fp;
+ char cmd[PATH_MAX];
+ struct inline_node *node;
+ char *filename = NULL;
+ size_t len;
+ unsigned int line_nr = 0;
+
+ scnprintf(cmd, sizeof(cmd), "addr2line -e %s -i %016"PRIx64,
+ dso_name, addr);
+
+ fp = popen(cmd, "r");
+ if (fp == NULL) {
+ pr_err("popen failed for %s\n", dso_name);
+ return NULL;
+ }
+
+ node = zalloc(sizeof(*node));
+ if (node == NULL) {
+ perror("not enough memory for the inline node");
+ goto out;
+ }
+
+ INIT_LIST_HEAD(&node->val);
+ node->addr = addr;
+
+ while (getline(&filename, &len, fp) != -1) {
+ if (filename_split(filename, &line_nr) != 1) {
+ free(filename);
+ goto out;
+ }
+
+ if (inline_list__append(filename, line_nr, node) != 0)
+ goto out;
+
+ filename = NULL;
+ }
+
+out:
+ pclose(fp);
+
+ if (list_empty(&node->val)) {
+ inline_node__free(node);
+ return NULL;
+ }
+
+ return node;
+}
+
#endif /* HAVE_LIBBFD_SUPPORT */

/*
@@ -311,7 +414,7 @@ char *__get_srcline(struct dso *dso, u64 addr, struct symbol *sym,
if (dso_name == NULL)
goto out;

- if (!addr2line(dso_name, addr, &file, &line, dso, unwind_inlines))
+ if (!addr2line(dso_name, addr, &file, &line, dso, unwind_inlines, NULL))
goto out;

if (asprintf(&srcline, "%s:%u",
@@ -351,3 +454,29 @@ char *get_srcline(struct dso *dso, u64 addr, struct symbol *sym,
{
return __get_srcline(dso, addr, sym, show_sym, false);
}
+
+struct inline_node *inline__node(struct dso *dso, u64 addr)
+{
+ const char *dso_name;
+
+ dso_name = dso__name(dso);
+ if (dso_name == NULL)
+ return NULL;
+
+ return addr2inlines(dso_name, addr, dso);
+}
+
+void inline_node__free(struct inline_node *node)
+{
+ struct inline_list *ilist, *tmp;
+
+ list_for_each_entry_safe(ilist, tmp, &node->val, list) {
+ list_del(&ilist->list);
+ if (ilist->filename != NULL)
+ free(ilist->filename);
+
+ free(ilist);
+ }
+
+ free(node);
+}
diff --git a/tools/perf/util/util.h b/tools/perf/util/util.h
index 1d639e3..74b7db0 100644
--- a/tools/perf/util/util.h
+++ b/tools/perf/util/util.h
@@ -363,4 +363,18 @@ int is_printable_array(char *p, unsigned int len);

int timestamp__scnprintf_usec(u64 timestamp, char *buf, size_t sz);

+struct inline_list {
+ char *filename;
+ unsigned int line_nr;
+ struct list_head list;
+};
+
+struct inline_node {
+ u64 addr;
+ struct list_head val;
+};
+
+struct inline_node *inline__node(struct dso *dso, u64 addr);
+void inline_node__free(struct inline_node *node);
+
#endif /* GIT_COMPAT_UTIL_H */
--
2.7.4