perf report: Find the inline stack for a given address

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 <yao.jin@linux.intel.com>
Tested-by: Milian Wolff <milian.wolff@kdab.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@intel.com>
Link: http://lkml.kernel.org/r/1490474069-15823-3-git-send-email-yao.jin@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

5 files changed, 192 insertions, 5 deletions

diff --git a/tools/perf/util/srcline.c b/tools/perf/util/srcline.c
index 2953c9fecb30..3ce28f702b36 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 +31,34 @@ 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
 
 /*
@@ -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;
@@ -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) {
@@ -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)
@@ -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];
@@ -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 */
 
 /*
@@ -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",
@@ -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);
+}
diff --git a/tools/perf/util/symbol-elf.c b/tools/perf/util/symbol-elf.c
index 0e660dba58ad..d1a40bb642ff 100644
--- a/tools/perf/util/symbol-elf.c
+++ b/tools/perf/util/symbol-elf.c
@@ -390,6 +390,11 @@ out_elf_end:
         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-minimal.c b/tools/perf/util/symbol-minimal.c
index 11cdde980545..870ef0f0659c 100644
--- a/tools/perf/util/symbol-minimal.c
+++ b/tools/perf/util/symbol-minimal.c
@@ -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;
+}
diff --git a/tools/perf/util/symbol.h b/tools/perf/util/symbol.h
index 9222c7e702f3..e36213ccfcf7 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 b2cfa47990dc..cc0700d6fef0 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 */