[PATCH v3 2.6.39-rc1-tip 23/26] 23: perf: show possible probes in a given executable file or library.

[Srikar Dronamraju <srikar at linux dot vnet dot ibm dot com>]

Enhances -F/--funcs option of "perf probe" to list possible probe points in
an executable file or library. A new option -e/--exe specifies the path of
the executable or library.


Show last 10 functions in /bin/zsh.

# perf probe -F -u -e /bin/zsh | tail
zstrtol
ztrcmp
ztrdup
ztrduppfx
ztrftime
ztrlen
ztrncpy
ztrsub
zwarn
zwarnnam

Show first 10 functions in /lib/libc.so.6

# perf probe -u -F -e /lib/libc.so.6 | head
_IO_adjust_column
_IO_adjust_wcolumn
_IO_default_doallocate
_IO_default_finish
_IO_default_pbackfail
_IO_default_uflow
_IO_default_xsgetn
_IO_default_xsputn
_IO_do_write@@GLIBC_2.2.5
_IO_doallocbuf

Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
---
 tools/perf/builtin-probe.c    |    9 +++++--
 tools/perf/util/probe-event.c |   56 +++++++++++++++++++++++++++++++----------
 tools/perf/util/probe-event.h |    4 +--
 tools/perf/util/symbol.c      |    8 ++++++
 tools/perf/util/symbol.h      |    1 +
 5 files changed, 61 insertions(+), 17 deletions(-)

diff --git a/tools/perf/builtin-probe.c b/tools/perf/builtin-probe.c
index 98db08f..6ceebea 100644
--- a/tools/perf/builtin-probe.c
+++ b/tools/perf/builtin-probe.c
@@ -57,6 +57,7 @@ static struct {
 	bool show_ext_vars;
 	bool show_funcs;
 	bool mod_events;
+	bool uprobes;
 	int nevents;
 	struct perf_probe_event events[MAX_PROBES];
 	struct strlist *dellist;
@@ -249,6 +250,10 @@ static const struct option options[] = {
 		 "Set how many probe points can be found for a probe."),
 	OPT_BOOLEAN('F', "funcs", &params.show_funcs,
 		    "Show potential probe-able functions."),
+	OPT_BOOLEAN('u', "uprobe", &params.uprobes,
+		    "user space probe events"),
+	OPT_STRING('e', "exe", &params.target,
+		   "executable", "userspace executable or library"),
 	OPT_CALLBACK('\0', "filter", NULL,
 		     "[!]FILTER", "Set a filter (with --vars/funcs only)\n"
 		     "\t\t\t(default: \"" DEFAULT_VAR_FILTER "\" for --vars,\n"
@@ -327,8 +332,8 @@ int cmd_probe(int argc, const char **argv, const char *prefix __used)
 		if (!params.filter)
 			params.filter = strfilter__new(DEFAULT_FUNC_FILTER,
 						       NULL);
-		ret = show_available_funcs(params.target,
-					   params.filter);
+		ret = show_available_funcs(params.target, params.filter,
+					params.uprobes);
 		strfilter__delete(params.filter);
 		if (ret < 0)
 			pr_err("  Error: Failed to show functions."
diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
index 09c53c1..cf77feb 100644
--- a/tools/perf/util/probe-event.c
+++ b/tools/perf/util/probe-event.c
@@ -47,6 +47,7 @@
 #include "trace-event.h"	/* For __unused */
 #include "probe-event.h"
 #include "probe-finder.h"
+#include "session.h"
 
 #define MAX_CMDLEN 256
 #define MAX_PROBE_ARGS 128
@@ -1963,6 +1964,7 @@ int del_perf_probe_events(struct strlist *dellist)
 
 	return ret;
 }
+
 /* TODO: don't use a global variable for filter ... */
 static struct strfilter *available_func_filter;
 
@@ -1979,30 +1981,58 @@ static int filter_available_functions(struct map *map __unused,
 	return 1;
 }
 
-int show_available_funcs(const char *elfobject, struct strfilter *_filter)
+static int __show_available_funcs(struct map *map)
+{
+	if (map__load(map, filter_available_functions)) {
+		pr_err("Failed to load map.\n");
+		return -EINVAL;
+	}
+	if (!dso__sorted_by_name(map->dso, map->type))
+		dso__sort_by_name(map->dso, map->type);
+
+	dso__fprintf_symbols_by_name(map->dso, map->type, stdout);
+	return 0;
+}
+
+static int available_kernel_funcs(const char *module)
 {
 	struct map *map;
 	int ret;
 
-	setup_pager();
-
 	ret = init_vmlinux();
 	if (ret < 0)
 		return ret;
 
-	map = kernel_get_module_map(elfobject);
+	map = kernel_get_module_map(module);
 	if (!map) {
-		pr_err("Failed to find %s map.\n", (elfobject) ? : "kernel");
+		pr_err("Failed to find %s map.\n", (module) ? : "kernel");
 		return -EINVAL;
 	}
+	return __show_available_funcs(map);
+}
+
+int show_available_funcs(const char *elfobject, struct strfilter *_filter,
+					bool user)
+{
+	struct map *map;
+	int ret;
+
+	setup_pager();
 	available_func_filter = _filter;
-	if (map__load(map, filter_available_functions)) {
-		pr_err("Failed to load map.\n");
-		return -EINVAL;
-	}
-	if (!dso__sorted_by_name(map->dso, map->type))
-		dso__sort_by_name(map->dso, map->type);
 
-	dso__fprintf_symbols_by_name(map->dso, map->type, stdout);
-	return 0;
+	if (!user)
+		return available_kernel_funcs(elfobject);
+
+	symbol_conf.try_vmlinux_path = false;
+	symbol_conf.sort_by_name = true;
+	ret = symbol__init();
+	if (ret < 0) {
+		pr_err("Failed to init symbol map.\n");
+		return ret;
+	}
+	map = dso__new_map(elfobject);
+	ret = __show_available_funcs(map);
+	dso__delete(map->dso);
+	map__delete(map);
+	return ret;
 }
diff --git a/tools/perf/util/probe-event.h b/tools/perf/util/probe-event.h
index 3434fc9..4c24a85 100644
--- a/tools/perf/util/probe-event.h
+++ b/tools/perf/util/probe-event.h
@@ -128,8 +128,8 @@ extern int show_line_range(struct line_range *lr, const char *module);
 extern int show_available_vars(struct perf_probe_event *pevs, int npevs,
 			       int max_probe_points, const char *module,
 			       struct strfilter *filter, bool externs);
-extern int show_available_funcs(const char *module, struct strfilter *filter);
-
+extern int show_available_funcs(const char *module, struct strfilter *filter,
+				bool user);
 
 /* Maximum index number of event-name postfix */
 #define MAX_EVENT_INDEX	1024
diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index f06c10f..eefeab4 100644
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -2606,3 +2606,11 @@ int machine__load_vmlinux_path(struct machine *self, enum map_type type,
 
 	return ret;
 }
+
+struct map *dso__new_map(const char *name)
+{
+	struct dso *dso = dso__new(name);
+	struct map *map = map__new2(0, dso, MAP__FUNCTION);
+
+	return map;
+}
diff --git a/tools/perf/util/symbol.h b/tools/perf/util/symbol.h
index 713b0b4..3838909 100644
--- a/tools/perf/util/symbol.h
+++ b/tools/perf/util/symbol.h
@@ -211,6 +211,7 @@ char dso__symtab_origin(const struct dso *self);
 void dso__set_long_name(struct dso *self, char *name);
 void dso__set_build_id(struct dso *self, void *build_id);
 void dso__read_running_kernel_build_id(struct dso *self, struct machine *machine);
+struct map *dso__new_map(const char *name);
 struct symbol *dso__find_symbol(struct dso *self, enum map_type type, u64 addr);
 struct symbol *dso__find_symbol_by_name(struct dso *self, enum map_type type,
 					const char *name);