Re: [PATCH v5 2/5] perf report: Find the inline stack for a given address

From: Arnaldo Carvalho de Melo
Date: Fri Mar 24 2017 - 14:37:55 EST


Em Fri, Mar 17, 2017 at 05:42:24AM +0800, Jin Yao escreveu:
> 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);

free() can be fed NULL, I'll simplify this thus

> + }
> +
> + 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