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perf report: Find the inline stack for a given address
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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).

If BFD lib is not supported, the result is only filename:line_nr.

Signed-off-by: Yao Jin <[email protected]>
Tested-by: Milian Wolff <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Kan Liang <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
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Jin Yao authored and acmel committed Mar 27, 2017
1 parent 5580338 commit a64489c
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Showing 5 changed files with 192 additions and 5 deletions.
167 changes: 162 additions & 5 deletions tools/perf/util/srcline.c
Original file line number Diff line number Diff line change
Expand Up @@ -7,6 +7,7 @@
#include "util/dso.h"
#include "util/util.h"
#include "util/debug.h"
#include "util/callchain.h"

#include "symbol.h"

Expand All @@ -30,6 +31,34 @@ 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;

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

list_add_tail(&ilist->list, &node->val);

return 0;
}

#ifdef HAVE_LIBBFD_SUPPORT

/*
Expand Down Expand Up @@ -169,9 +198,17 @@ static void addr2line_cleanup(struct a2l_data *a2l)

#define MAX_INLINE_NEST 1024

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);
}

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;
Expand All @@ -196,8 +233,21 @@ 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) {
Expand All @@ -223,6 +273,35 @@ 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)
Expand All @@ -249,7 +328,8 @@ 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];
Expand Down Expand Up @@ -288,6 +368,58 @@ 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,
NULL) != 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 */

/*
Expand All @@ -311,7 +443,7 @@ 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",
Expand Down Expand Up @@ -351,3 +483,28 @@ 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);
zfree(&ilist->filename);
zfree(&ilist->funcname);
free(ilist);
}

free(node);
}
5 changes: 5 additions & 0 deletions tools/perf/util/symbol-elf.c
Original file line number Diff line number Diff line change
Expand Up @@ -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.
*/
Expand Down
7 changes: 7 additions & 0 deletions tools/perf/util/symbol-minimal.c
Original file line number Diff line number Diff line change
Expand Up @@ -373,3 +373,10 @@ int kcore_copy(const char *from_dir __maybe_unused,
void symbol__elf_init(void)
{
}

char *dso__demangle_sym(struct dso *dso __maybe_unused,
int kmodule __maybe_unused,
char *elf_name __maybe_unused)
{
return NULL;
}
2 changes: 2 additions & 0 deletions tools/perf/util/symbol.h
Original file line number Diff line number Diff line change
Expand Up @@ -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);
Expand Down
16 changes: 16 additions & 0 deletions tools/perf/util/util.h
Original file line number Diff line number Diff line change
Expand Up @@ -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 */

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