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

[Arnaldo Carvalho de Melo <acme@kernel.org>]

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@linux.intel.com>
> Tested-by: Milian Wolff <milian.wolff@kdab.com>
> ---
>  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