[PATCHv11 2.6.36-rc2-tip 12/15] 12: perf: show possible probes in a given file.

From: Srikar Dronamraju
Date: Wed Aug 25 2010 - 09:48:41 EST


Introduces -S/--show_functions option for perf-probe.
This lists function names in a File. If no file is specified, then lists
functions in the current running kernel.

Signed-off-by: Srikar Dronamraju <srikar@xxxxxxxxxxxxxxxxxx>
---

Changelog from V10: As suggested by Arnaldo, filtering is now
based on sym.binding.

Changelog from V9: Filter labels, weak, and local binding functions
from listing as suggested by Christoph Hellwig.

Show last 10 functions in /bin/zsh.

# perf probe -S -D /bin/zsh | tail
zstrtol
ztrcmp
ztrdup
ztrduppfx
ztrftime
ztrlen
ztrncpy
ztrsub
zwarn
zwarnnam

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

# perf probe -S -D /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

Show last 10 functions in kernel.

# perf probe -S | tail
zlib_inflateInit2
zlib_inflateReset
zlib_inflate_blob
zlib_inflate_table
zlib_inflate_workspacesize
zone_pcp_update
zone_reclaim
zone_reclaimable_pages
zone_statistics
zone_watermark_ok

tools/perf/builtin-probe.c | 43 ++++++++++++++++++++++++
tools/perf/util/probe-event.c | 72 +++++++++++++++++++++++++++++++++++++++++
tools/perf/util/probe-event.h | 1 +
tools/perf/util/symbol.c | 8 +++++
tools/perf/util/symbol.h | 1 +
5 files changed, 124 insertions(+), 1 deletions(-)

diff --git a/tools/perf/builtin-probe.c b/tools/perf/builtin-probe.c
index 199d5e1..fa63245 100644
--- a/tools/perf/builtin-probe.c
+++ b/tools/perf/builtin-probe.c
@@ -50,9 +50,11 @@ static struct {
bool list_events;
bool force_add;
bool show_lines;
+ bool list_functions;
int nevents;
struct perf_probe_event events[MAX_PROBES];
struct strlist *dellist;
+ struct strlist *limitlist;
struct line_range line_range;
int max_probe_points;
} params;
@@ -132,6 +134,19 @@ static int opt_show_lines(const struct option *opt __used,
}
#endif

+static int opt_limit_dsos(const struct option *opt __used,
+ const char *str, int unset __used)
+{
+ if (str) {
+ if (!params.limitlist)
+ params.limitlist = strlist__new(true, NULL);
+ if (!params.limitlist)
+ return -1;
+ strlist__add(params.limitlist, str);
+ }
+ return 0;
+}
+
static const char * const probe_usage[] = {
"perf probe [<options>] 'PROBEDEF' ['PROBEDEF' ...]",
"perf probe [<options>] --add 'PROBEDEF' [--add 'PROBEDEF' ...]",
@@ -188,6 +203,10 @@ static const struct option options[] = {
OPT__DRY_RUN(&probe_event_dry_run),
OPT_INTEGER('\0', "max-probes", &params.max_probe_points,
"Set how many probe points can be found for a probe."),
+ OPT_BOOLEAN('S', "show_functions", &params.list_functions,
+ "Show potential probes."),
+ OPT_CALLBACK('D', "limit_dsos", NULL, "DSO",
+ "Limit Dsos.", opt_limit_dsos),
OPT_END()
};

@@ -213,7 +232,7 @@ int cmd_probe(int argc, const char **argv, const char *prefix __used)
params.max_probe_points = MAX_PROBES;

if ((!params.nevents && !params.dellist && !params.list_events &&
- !params.show_lines))
+ !params.show_lines && !params.list_functions))
usage_with_options(probe_usage, options);

if (params.list_events) {
@@ -225,12 +244,34 @@ int cmd_probe(int argc, const char **argv, const char *prefix __used)
pr_err(" Error: Don't use --list with --line.\n");
usage_with_options(probe_usage, options);
}
+ if (params.list_functions) {
+ pr_warning(" Error: Don't use --list with"
+ " --show_functions.\n");
+ usage_with_options(probe_usage, options);
+ }
ret = show_perf_probe_events();
if (ret < 0)
pr_err(" Error: Failed to show event list. (%d)\n",
ret);
return ret;
}
+ if (params.list_functions) {
+ if (params.nevents != 0 || params.dellist) {
+ pr_err(" Error: Don't use --show_functions with"
+ " --add/--del.\n");
+ usage_with_options(probe_usage, options);
+ }
+ if (params.show_lines) {
+ pr_err(" Error: Don't use --show_functions with"
+ " --line.\n");
+ usage_with_options(probe_usage, options);
+ }
+ ret = show_possible_probes(params.limitlist);
+ if (ret < 0)
+ pr_err(" Error: Failed to show possible"
+ " probes (%d).\n", ret);
+ return ret;
+ }

#ifdef DWARF_SUPPORT
if (params.show_lines) {
diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
index e72f05c..2efbe4b 100644
--- a/tools/perf/util/probe-event.c
+++ b/tools/perf/util/probe-event.c
@@ -31,6 +31,7 @@
#include <string.h>
#include <stdarg.h>
#include <limits.h>
+#include <gelf.h>

#undef _GNU_SOURCE
#include "util.h"
@@ -46,6 +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
@@ -1752,3 +1754,73 @@ int del_perf_probe_events(struct strlist *dellist)
return ret;
}

+/*
+ * If a symbol corresponds to a function with global binding return 0.
+ * For all others return 1.
+ */
+static int filter_non_global_functions(struct map *map __unused,
+ struct symbol *sym)
+{
+ if (sym->binding != STB_GLOBAL)
+ return 1;
+
+ return 0;
+}
+
+static int print_list_available_symbols(struct map *map,
+ const char *name __unused)
+{
+ if (map__load(map, filter_non_global_functions) < 0)
+ return -EINVAL;
+ if (!dso__sorted_by_name(map->dso, map->type))
+ dso__sort_by_name(map->dso, map->type);
+
+ dso__fprintf_symbols(map->dso, map->type, stdout);
+ return 0;
+}
+
+int show_possible_probes(struct strlist *limitlist)
+{
+ struct str_node *ent;
+ struct map *map = NULL;
+ char *str;
+ int ret = -EINVAL;
+
+ if (!limitlist) { /* Show functions in kernel */
+ ret = init_vmlinux();
+ if (ret < 0)
+ return ret;
+ return print_list_available_symbols(
+ machine.vmlinux_maps[MAP__FUNCTION], NULL);
+ }
+
+ symbol_conf.try_vmlinux_path = false;
+ symbol_conf.sort_by_name = true;
+ ret = symbol__init();
+ if (ret < 0) {
+ pr_debug("Failed to init symbol map.\n");
+ return ret;
+ }
+
+ strlist__for_each(ent, limitlist) {
+ str = strdup(ent->s);
+ if (!str) {
+ ret = -ENOMEM;
+ goto out_delete;
+ }
+
+ map = dso__new_map(str);
+ ret = print_list_available_symbols(map, NULL);
+ if (ret)
+ pr_warning("No Symbols in dso %s.\n", str);
+
+ dso__delete(map->dso);
+ map__delete(map);
+ free(str);
+ }
+
+out_delete:
+ if (ret)
+ pr_warning("Failed to list available probes.\n");
+ return ret;
+}
diff --git a/tools/perf/util/probe-event.h b/tools/perf/util/probe-event.h
index 5af3924..fcd0f08 100644
--- a/tools/perf/util/probe-event.h
+++ b/tools/perf/util/probe-event.h
@@ -115,6 +115,7 @@ extern int add_perf_probe_events(struct perf_probe_event *pevs, int npevs,
extern int del_perf_probe_events(struct strlist *dellist);
extern int show_perf_probe_events(void);
extern int show_line_range(struct line_range *lr);
+extern int show_possible_probes(struct strlist *availlist);


/* Maximum index number of event-name postfix */
diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index ca22032..385f0a4 100644
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -2464,3 +2464,11 @@ int machine__load_vmlinux_path(struct machine *self, enum map_type type,

return ret;
}
+
+struct map *dso__new_map(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 72ef973..52a8126 100644
--- a/tools/perf/util/symbol.h
+++ b/tools/perf/util/symbol.h
@@ -202,6 +202,7 @@ 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(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);
--
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