[PATCH v4 2/5] perf report: Find the inline stack for a given address

From: Jin Yao
Date: Fri Mar 03 2017 - 01:38:09 EST


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 (filename:line_nr and funcname).

Signed-off-by: Jin Yao <yao.jin@xxxxxxxxxxxxxxx>
Tested-by: Milian Wolff <milian.wolff@xxxxxxxx>
---
tools/perf/util/srcline.c | 169 +++++++++++++++++++++++++++++++++++++++++--
tools/perf/util/symbol-elf.c | 5 ++
tools/perf/util/symbol.h | 2 +
tools/perf/util/util.h | 16 ++++
4 files changed, 187 insertions(+), 5 deletions(-)

diff --git a/tools/perf/util/srcline.c b/tools/perf/util/srcline.c
index 2953c9f..f9d4b47 100644
--- a/tools/perf/util/srcline.c
+++ b/tools/perf/util/srcline.c
@@ -7,6 +7,7 @@
#include "util/dso.h"
#include "util/util.h"
#include "util/debug.h"
+#include "util/callchain.h"

#include "symbol.h"

@@ -30,6 +31,41 @@ static const char *dso__name(struct dso *dso)
return dso_name;
}

+static int inline_list__append(char *filename, char *funcname, int line_nr,
+ struct inline_node *node, struct dso *dso)
+{
+ struct inline_list *ilist;
+ char *demangled;
+
+ ilist = zalloc(sizeof(*ilist));
+ if (ilist == NULL)
+ return -1;
+
+ ilist->filename = filename;
+ ilist->line_nr = line_nr;
+
+ demangled = dso__demangle_sym(dso, 0, funcname);
+ if (demangled == NULL) {
+ ilist->funcname = funcname;
+ } else {
+ ilist->funcname = demangled;
+ if (funcname != NULL)
+ free(funcname);
+ }
+
+ list_add_tail(&ilist->list, &node->val);
+
+ return 0;
+}
+
+static void inline_list__reverse(struct inline_node *node)
+{
+ struct inline_list *ilist, *n;
+
+ list_for_each_entry_safe_reverse(ilist, n, &node->val, list)
+ list_move_tail(&ilist->list, &node->val);
+}
+
#ifdef HAVE_LIBBFD_SUPPORT

/*
@@ -171,7 +207,7 @@ 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 +232,21 @@ 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),
+ strdup(a2l->funcname),
+ a2l->line, node,
+ dso) != 0)
+ return 0;
+ }
+ }
+
+ if ((node != NULL) &&
+ (callchain_param.order != ORDER_CALLEE)) {
+ inline_list__reverse(node);
+ }
}

if (a2l->found && a2l->filename) {
@@ -223,6 +272,35 @@ 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))
+ goto out_free_inline_node;
+
+ if (list_empty(&node->val))
+ goto out_free_inline_node;
+
+ return node;
+
+out_free_inline_node:
+ inline_node__delete(node);
+ return NULL;
+}
+
#else /* HAVE_LIBBFD_SUPPORT */

static int filename_split(char *filename, unsigned int *line_nr)
@@ -249,7 +327,8 @@ 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 +367,57 @@ 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, NULL, line_nr, node) != 0)
+ goto out;
+
+ filename = NULL;
+ }
+
+out:
+ pclose(fp);
+
+ if (list_empty(&node->val)) {
+ inline_node__delete(node);
+ return NULL;
+ }
+
+ return node;
+}
+
#endif /* HAVE_LIBBFD_SUPPORT */

/*
@@ -311,7 +441,7 @@ 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 +481,32 @@ char *get_srcline(struct dso *dso, u64 addr, struct symbol *sym,
{
return __get_srcline(dso, addr, sym, show_sym, false);
}
+
+struct inline_node *dso__parse_addr_inlines(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__delete(struct inline_node *node)
+{
+ struct inline_list *ilist, *tmp;
+
+ list_for_each_entry_safe(ilist, tmp, &node->val, list) {
+ list_del_init(&ilist->list);
+ if (ilist->filename != NULL)
+ free(ilist->filename);
+
+ if (ilist->funcname != NULL)
+ free(ilist->funcname);
+
+ free(ilist);
+ }
+
+ free(node);
+}
diff --git a/tools/perf/util/symbol-elf.c b/tools/perf/util/symbol-elf.c
index 4e59dde..3a1dda3 100644
--- a/tools/perf/util/symbol-elf.c
+++ b/tools/perf/util/symbol-elf.c
@@ -390,6 +390,11 @@ int dso__synthesize_plt_symbols(struct dso *dso, struct symsrc *ss, struct map *
return 0;
}

+char *dso__demangle_sym(struct dso *dso, int kmodule, char *elf_name)
+{
+ return demangle_sym(dso, kmodule, elf_name);
+}
+
/*
* Align offset to 4 bytes as needed for note name and descriptor data.
*/
diff --git a/tools/perf/util/symbol.h b/tools/perf/util/symbol.h
index 6c358b7..8adf045 100644
--- a/tools/perf/util/symbol.h
+++ b/tools/perf/util/symbol.h
@@ -305,6 +305,8 @@ int dso__load_sym(struct dso *dso, struct map *map, struct symsrc *syms_ss,
int dso__synthesize_plt_symbols(struct dso *dso, struct symsrc *ss,
struct map *map);

+char *dso__demangle_sym(struct dso *dso, int kmodule, char *elf_name);
+
void __symbols__insert(struct rb_root *symbols, struct symbol *sym, bool kernel);
void symbols__insert(struct rb_root *symbols, struct symbol *sym);
void symbols__fixup_duplicate(struct rb_root *symbols);
diff --git a/tools/perf/util/util.h b/tools/perf/util/util.h
index b2cfa47..cc0700d 100644
--- a/tools/perf/util/util.h
+++ b/tools/perf/util/util.h
@@ -364,4 +364,20 @@ int is_printable_array(char *p, unsigned int len);
int timestamp__scnprintf_usec(u64 timestamp, char *buf, size_t sz);

int unit_number__scnprintf(char *buf, size_t size, u64 n);
+
+struct inline_list {
+ char *filename;
+ char *funcname;
+ unsigned int line_nr;
+ struct list_head list;
+};
+
+struct inline_node {
+ u64 addr;
+ struct list_head val;
+};
+
+struct inline_node *dso__parse_addr_inlines(struct dso *dso, u64 addr);
+void inline_node__delete(struct inline_node *node);
+
#endif /* GIT_COMPAT_UTIL_H */
--
2.7.4