[PATCH v3 03/13] perf report: create real callchain entries for inlined frames

Milian Wolff
2017-09-06T13:59:06Z

The inlined frames use a fake symbol that is maintained by
inline_node which in turn is maintained by the dso->inlines tree.
This tree is always sorted by name. All other entries of the symbol
beside the function name are unused for inline frames. The advantage
of this approach is that all existing users of the callchain API can
now transparently display inlined frames without having to patch
their code.

Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Yao Jin <yao.jin@linux.intel.com>
Signed-off-by: Milian Wolff <milian.wolff@kdab.com>
---
tools/perf/util/dso.c | 2 +
tools/perf/util/dso.h | 1 +
tools/perf/util/machine.c | 37 +++++++++
tools/perf/util/srcline.c | 186 ++++++++++++++++++++++++++++++++++++----------
tools/perf/util/srcline.h | 19 ++++-
tools/perf/util/symbol.h | 1 +
6 files changed, 203 insertions(+), 43 deletions(-)

diff --git a/tools/perf/util/dso.c b/tools/perf/util/dso.c
index b9e087fb8247..72e6e390fd26 100644
--- a/tools/perf/util/dso.c
+++ b/tools/perf/util/dso.c
@@ -9,6 +9,7 @@
#include "compress.h"
#include "path.h"
#include "symbol.h"
+#include "srcline.h"
#include "dso.h"
#include "machine.h"
#include "auxtrace.h"
@@ -1233,6 +1234,7 @@ void dso__delete(struct dso *dso)
dso->long_name);
for (i = 0; i < MAP__NR_TYPES; ++i)
symbols__delete(&dso->symbols[i]);
+ inlines__tree_delete(&dso->inlined_nodes);

if (dso->short_name_allocated) {
zfree((char **)&dso->short_name);
diff --git a/tools/perf/util/dso.h b/tools/perf/util/dso.h
index f886141678eb..7d1e2b3c1f10 100644
--- a/tools/perf/util/dso.h
+++ b/tools/perf/util/dso.h
@@ -141,6 +141,7 @@ struct dso {
struct rb_root *root; /* root of rbtree that rb_node is in */
struct rb_root symbols[MAP__NR_TYPES];
struct rb_root symbol_names[MAP__NR_TYPES];
+ struct rb_root inlined_nodes;
struct {
u64 addr;
struct symbol *symbol;
diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c
index 5c8286a7d7d6..206526d3b509 100644
--- a/tools/perf/util/machine.c
+++ b/tools/perf/util/machine.c
@@ -2079,6 +2079,40 @@ static int thread__resolve_callchain_sample(struct thread *thread,
return 0;
}

+static int append_inlines(struct callchain_cursor *cursor,
+ struct map *map, struct symbol *sym, u64 ip)
+{
+ struct inline_node *inline_node;
+ struct inline_list *ilist;
+ u64 addr;
+
+ if (!symbol_conf.inline_name || !map || !sym)
+ return 1;
+
+ addr = map__rip_2objdump(map, ip);
+
+ inline_node = inlines__tree_find(&map->dso->inlined_nodes, addr);
+ if (!inline_node) {
+ inline_node = dso__parse_addr_inlines(map->dso, addr, sym);
+ if (!inline_node)
+ return 1;
+
+ inlines__tree_insert(&map->dso->inlined_nodes, inline_node);
+ }
+
+ list_for_each_entry(ilist, &inline_node->val, list) {
+ int ret = callchain_cursor_append(cursor, ip, map,
+ ilist->symbol, false,
+ NULL, 0, 0, 0,
+ ilist->srcline);
+
+ if (ret != 0)
+ return ret;
+ }
+
+ return 0;
+}
+
static int unwind_entry(struct unwind_entry *entry, void *arg)
{
struct callchain_cursor *cursor = arg;
@@ -2087,6 +2121,9 @@ static int unwind_entry(struct unwind_entry *entry, void *arg)
if (symbol_conf.hide_unresolved && entry->sym == NULL)
return 0;

+ if (append_inlines(cursor, entry->map, entry->sym, entry->ip) == 0)
+ return 0;
+
srcline = callchain_srcline(entry->map, entry->sym, entry->ip);
return callchain_cursor_append(cursor, entry->ip,
entry->map, entry->sym,
diff --git a/tools/perf/util/srcline.c b/tools/perf/util/srcline.c
index ed8e8d2de942..87f148c0d094 100644
--- a/tools/perf/util/srcline.c
+++ b/tools/perf/util/srcline.c
@@ -33,28 +33,17 @@ 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)
+static int inline_list__append(struct symbol *symbol, char *srcline,
+ struct inline_node *node)
{
struct inline_list *ilist;
- char *demangled;

ilist = zalloc(sizeof(*ilist));
if (ilist == NULL)
return -1;

- ilist->filename = filename;
- ilist->line_nr = line_nr;
-
- if (dso != NULL) {
- demangled = dso__demangle_sym(dso, 0, funcname);
- if (demangled == NULL) {
- ilist->funcname = funcname;
- } else {
- ilist->funcname = demangled;
- free(funcname);
- }
- }
+ ilist->symbol = symbol;
+ ilist->srcline = srcline;

if (callchain_param.order == ORDER_CALLEE)
list_add_tail(&ilist->list, &node->val);
@@ -64,6 +53,30 @@ static int inline_list__append(char *filename, char *funcname, int line_nr,
return 0;
}

+// basename version that takes a const input string
+static const char *gnu_basename(const char *path)
+{
+ const char *base = strrchr(path, '/');
+
+ return base ? base + 1 : path;
+}
+
+static char *srcline_from_fileline(const char *file, unsigned int line)
+{
+ char *srcline;
+
+ if (!file)
+ return NULL;
+
+ if (!srcline_full_filename)
+ file = gnu_basename(file);
+
+ if (asprintf(&srcline, "%s:%u", file, line) < 0)
+ return NULL;
+
+ return srcline;
+}
+
#ifdef HAVE_LIBBFD_SUPPORT

/*
@@ -206,19 +219,58 @@ static void addr2line_cleanup(struct a2l_data *a2l)

#define MAX_INLINE_NEST 1024

+static struct symbol *new_inline_sym(struct dso *dso,
+ struct symbol *base_sym,
+ const char *funcname)
+{
+ struct symbol *inline_sym;
+ char *demangled = NULL;
+
+ if (dso) {
+ demangled = dso__demangle_sym(dso, 0, funcname);
+ if (demangled)
+ funcname = demangled;
+ }
+
+ if (strcmp(funcname, base_sym->name) == 0) {
+ // reuse the real, existing symbol
+ inline_sym = base_sym;
+ // ensure that we don't alias an inlined symbol, which could
+ // lead to double frees in inline_node__delete
+ assert(!base_sym->inlined);
+ } else {
+ // create a fake symbol for the inline frame
+ inline_sym = symbol__new(base_sym ? base_sym->start : 0,
+ base_sym ? base_sym->end : 0,
+ base_sym ? base_sym->binding : 0,
+ funcname);
+ if (inline_sym)
+ inline_sym->inlined = 1;
+ }
+
+ free(demangled);
+
+ return inline_sym;
+}
+
static int inline_list__append_dso_a2l(struct dso *dso,
- struct inline_node *node)
+ struct inline_node *node,
+ struct symbol *sym)
{
struct a2l_data *a2l = dso->a2l;
- char *funcname = a2l->funcname ? strdup(a2l->funcname) : NULL;
- char *filename = a2l->filename ? strdup(a2l->filename) : NULL;
+ struct symbol *inline_sym = new_inline_sym(dso, sym, a2l->funcname);
+ char *srcline = NULL;
+
+ if (a2l->filename)
+ srcline = srcline_from_fileline(a2l->filename, a2l->line);

- return inline_list__append(filename, funcname, a2l->line, node, dso);
+ return inline_list__append(inline_sym, srcline, node);
}

static int addr2line(const char *dso_name, u64 addr,
char **file, unsigned int *line, struct dso *dso,
- bool unwind_inlines, struct inline_node *node)
+ bool unwind_inlines, struct inline_node *node,
+ struct symbol *sym)
{
int ret = 0;
struct a2l_data *a2l = dso->a2l;
@@ -244,7 +296,7 @@ static int addr2line(const char *dso_name, u64 addr,
if (unwind_inlines) {
int cnt = 0;

- if (node && inline_list__append_dso_a2l(dso, node))
+ if (node && inline_list__append_dso_a2l(dso, node, sym))
return 0;

while (bfd_find_inliner_info(a2l->abfd, &a2l->filename,
@@ -255,7 +307,7 @@ static int addr2line(const char *dso_name, u64 addr,
a2l->filename = NULL;

if (node != NULL) {
- if (inline_list__append_dso_a2l(dso, node))
+ if (inline_list__append_dso_a2l(dso, node, sym))
return 0;
// found at least one inline frame
ret = 1;
@@ -287,7 +339,7 @@ void dso__free_a2l(struct dso *dso)
}

static struct inline_node *addr2inlines(const char *dso_name, u64 addr,
- struct dso *dso)
+ struct dso *dso, struct symbol *sym)
{
struct inline_node *node;

@@ -300,7 +352,7 @@ static struct inline_node *addr2inlines(const char *dso_name, u64 addr,
INIT_LIST_HEAD(&node->val);
node->addr = addr;

- if (!addr2line(dso_name, addr, NULL, NULL, dso, TRUE, node))
+ if (!addr2line(dso_name, addr, NULL, NULL, dso, TRUE, node, sym))
goto out_free_inline_node;

if (list_empty(&node->val))
@@ -340,7 +392,8 @@ 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,
- struct inline_node *node __maybe_unused)
+ struct inline_node *node __maybe_unused,
+ struct symbol *sym __maybe_unused)
{
FILE *fp;
char cmd[PATH_MAX];
@@ -380,7 +433,7 @@ 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)
+ struct dso *dso __maybe_unused, struct symbol *sym)
{
FILE *fp;
char cmd[PATH_MAX];
@@ -408,13 +461,15 @@ static struct inline_node *addr2inlines(const char *dso_name, u64 addr,
node->addr = addr;

while (getline(&filename, &len, fp) != -1) {
+ char *srcline;
+
if (filename_split(filename, &line_nr) != 1) {
free(filename);
goto out;
}

- if (inline_list__append(filename, NULL, line_nr, node,
- NULL) != 0)
+ srcline = srcline_from_fileline(filename, line_nr);
+ if (inline_list__append(sym, srcline, node) != 0)
goto out;

filename = NULL;
@@ -454,19 +509,18 @@ 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, NULL))
+ if (!addr2line(dso_name, addr, &file, &line, dso,
+ unwind_inlines, NULL, sym))
goto out;

- if (asprintf(&srcline, "%s:%u",
- srcline_full_filename ? file : basename(file),
- line) < 0) {
- free(file);
+ srcline = srcline_from_fileline(file, line);
+ free(file);
+
+ if (!srcline)
goto out;
- }

dso->a2l_fails = 0;

- free(file);
return srcline;

out:
@@ -500,7 +554,8 @@ char *get_srcline(struct dso *dso, u64 addr, struct symbol *sym,
return __get_srcline(dso, addr, sym, show_sym, show_addr, false);
}

-struct inline_node *dso__parse_addr_inlines(struct dso *dso, u64 addr)
+struct inline_node *dso__parse_addr_inlines(struct dso *dso, u64 addr,
+ struct symbol *sym)
{
const char *dso_name;

@@ -508,7 +563,7 @@ struct inline_node *dso__parse_addr_inlines(struct dso *dso, u64 addr)
if (dso_name == NULL)
return NULL;

- return addr2inlines(dso_name, addr, dso);
+ return addr2inlines(dso_name, addr, dso, sym);
}

void inline_node__delete(struct inline_node *node)
@@ -517,10 +572,63 @@ void inline_node__delete(struct inline_node *node)

list_for_each_entry_safe(ilist, tmp, &node->val, list) {
list_del_init(&ilist->list);
- zfree(&ilist->filename);
- zfree(&ilist->funcname);
+ zfree(&ilist->srcline);
+ // only the inlined symbols are owned by the list
+ if (ilist->symbol && ilist->symbol->inlined)
+ symbol__delete(ilist->symbol);
free(ilist);
}

free(node);
}
+
+void inlines__tree_insert(struct rb_root *tree, struct inline_node *inlines)
+{
+ struct rb_node **p = &tree->rb_node;
+ struct rb_node *parent = NULL;
+ const u64 addr = inlines->addr;
+ struct inline_node *i;
+
+ while (*p != NULL) {
+ parent = *p;
+ i = rb_entry(parent, struct inline_node, rb_node);
+ if (addr < i->addr)
+ p = &(*p)->rb_left;
+ else
+ p = &(*p)->rb_right;
+ }
+ rb_link_node(&inlines->rb_node, parent, p);
+ rb_insert_color(&inlines->rb_node, tree);
+}
+
+struct inline_node *inlines__tree_find(struct rb_root *tree, u64 addr)
+{
+ struct rb_node *n = tree->rb_node;
+
+ while (n) {
+ struct inline_node *i = rb_entry(n, struct inline_node,
+ rb_node);
+
+ if (addr < i->addr)
+ n = n->rb_left;
+ else if (addr > i->addr)
+ n = n->rb_right;
+ else
+ return i;
+ }
+
+ return NULL;
+}
+
+void inlines__tree_delete(struct rb_root *tree)
+{
+ struct inline_node *pos;
+ struct rb_node *next = rb_first(tree);
+
+ while (next) {
+ pos = rb_entry(next, struct inline_node, rb_node);
+ next = rb_next(&pos->rb_node);
+ rb_erase(&pos->rb_node, tree);
+ inline_node__delete(pos);
+ }
+}
diff --git a/tools/perf/util/srcline.h b/tools/perf/util/srcline.h
index 7b52ba88676e..0d2aca92e8c7 100644
--- a/tools/perf/util/srcline.h
+++ b/tools/perf/util/srcline.h
@@ -2,6 +2,7 @@
#define PERF_SRCLINE_H

#include <linux/list.h>
+#include <linux/rbtree.h>
#include <linux/types.h>

struct dso;
@@ -17,18 +18,28 @@ void free_srcline(char *srcline);
#define SRCLINE_UNKNOWN ((char *) "??:0")

struct inline_list {
- char *filename;
- char *funcname;
- unsigned int line_nr;
+ struct symbol *symbol;
+ char *srcline;
struct list_head list;
};

struct inline_node {
u64 addr;
struct list_head val;
+ struct rb_node rb_node;
};

-struct inline_node *dso__parse_addr_inlines(struct dso *dso, u64 addr);
+// parse inlined frames for the given address
+struct inline_node *dso__parse_addr_inlines(struct dso *dso, u64 addr,
+ struct symbol *sym);
+// free resources associated to the inline node list
void inline_node__delete(struct inline_node *node);

+// insert the inline node list into the DSO, which will take ownership
+void inlines__tree_insert(struct rb_root *tree, struct inline_node *inlines);
+// find previously inserted inline node list
+struct inline_node *inlines__tree_find(struct rb_root *tree, u64 addr);
+// delete all nodes within the tree of inline_node s
+void inlines__tree_delete(struct rb_root *tree);
+
#endif /* PERF_SRCLINE_H */
diff --git a/tools/perf/util/symbol.h b/tools/perf/util/symbol.h
index 2bd6a1f01a1c..8f072c28b6d3 100644
--- a/tools/perf/util/symbol.h
+++ b/tools/perf/util/symbol.h
@@ -59,6 +59,7 @@ struct symbol {
u8 binding;
u8 idle:1;
u8 ignore:1;
+ u8 inlined:1;
u8 arch_sym;
char name[0];
};
--
2.14.1