Merge tag 'perf-core-for-mingo-4.11-20170126' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/core

Pull the latest perf/core updates from Arnaldo Carvalho de Melo:

New features:

 - Introduce 'perf ftrace' a perf front end to the kernel's ftrace
   function and function_graph tracer, defaulting to the "function_graph"
   tracer, more work will be done in reviving this effort, forward porting
   it from its initial patch submission (Namhyung Kim)

 - Add 'e' and 'c' hotkeys to expand/collapse call chains for a single
   hist entry in the 'perf report' and 'perf top' TUI (Jiri Olsa)

Fixes:

 - Fix wrong register name for arm64, used in 'perf probe' (He Kuang)

 - Fix map offsets in relocation in libbpf (Joe Stringer)

 - Fix looking up dwarf unwind stack info (Matija Glavinic Pecotic)

Infrastructure changes:

 - libbpf prog functions sync with what is exported via uapi (Joe Stringer)

Trivial changes:

 - Remove unnecessary checks and assignments in 'perf probe's
   try_to_find_absolute_address() (Markus Elfring)

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

9 files changed, 211 insertions, 40 deletions

diff --git a/tools/perf/util/dso.c b/tools/perf/util/dso.c
index d2c6cdd9d42b..28d41e709128 100644
--- a/tools/perf/util/dso.c
+++ b/tools/perf/util/dso.c
@@ -9,6 +9,13 @@
 #include "debug.h"
 #include "vdso.h"
 
+static const char * const debuglink_paths[] = {
+	"%.0s%s",
+	"%s/%s",
+	"%s/.debug/%s",
+	"/usr/lib/debug%s/%s"
+};
+
 char dso__symtab_origin(const struct dso *dso)
 {
 	static const char origin[] = {
@@ -44,24 +51,43 @@ int dso__read_binary_type_filename(const struct dso *dso,
 	size_t len;
 
 	switch (type) {
-	case DSO_BINARY_TYPE__DEBUGLINK: {
-		char *debuglink;
+	case DSO_BINARY_TYPE__DEBUGLINK:
+	{
+		const char *last_slash;
+		char dso_dir[PATH_MAX];
+		char symfile[PATH_MAX];
+		unsigned int i;
 
 		len = __symbol__join_symfs(filename, size, dso->long_name);
-		debuglink = filename + len;
-		while (debuglink != filename && *debuglink != '/')
-			debuglink--;
-		if (*debuglink == '/')
-			debuglink++;
+		last_slash = filename + len;
+		while (last_slash != filename && *last_slash != '/')
+			last_slash--;
 
-		ret = -1;
-		if (!is_regular_file(filename))
+		strncpy(dso_dir, filename, last_slash - filename);
+		dso_dir[last_slash-filename] = '\0';
+
+		if (!is_regular_file(filename)) {
+			ret = -1;
+			break;
+		}
+
+		ret = filename__read_debuglink(filename, symfile, PATH_MAX);
+		if (ret)
 			break;
 
-		ret = filename__read_debuglink(filename, debuglink,
-					       size - (debuglink - filename));
+		/* Check predefined locations where debug file might reside */
+		ret = -1;
+		for (i = 0; i < ARRAY_SIZE(debuglink_paths); i++) {
+			snprintf(filename, size,
+					debuglink_paths[i], dso_dir, symfile);
+			if (is_regular_file(filename)) {
+				ret = 0;
+				break;
+			}
 		}
+
 		break;
+	}
 	case DSO_BINARY_TYPE__BUILD_ID_CACHE:
 		if (dso__build_id_filename(dso, filename, size) == NULL)
 			ret = -1;
diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
index 00fd8a8850d3..c567d9f0aa92 100644
--- a/tools/perf/util/header.c
+++ b/tools/perf/util/header.c
@@ -2803,8 +2803,10 @@ static int perf_evsel__prepare_tracepoint_event(struct perf_evsel *evsel,
 	}
 
 	event = pevent_find_event(pevent, evsel->attr.config);
-	if (event == NULL)
+	if (event == NULL) {
+		pr_debug("cannot find event format for %d\n", (int)evsel->attr.config);
 		return -1;
+	}
 
 	if (!evsel->name) {
 		snprintf(bf, sizeof(bf), "%s:%s", event->system, event->name);
diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
index 6a6f44dd594b..2c1bca240597 100644
--- a/tools/perf/util/probe-event.c
+++ b/tools/perf/util/probe-event.c
@@ -3023,20 +3023,17 @@ static int try_to_find_absolute_address(struct perf_probe_event *pev,
 
 	tev->nargs = pev->nargs;
 	tev->args = zalloc(sizeof(struct probe_trace_arg) * tev->nargs);
-	if (!tev->args) {
-		err = -ENOMEM;
+	if (!tev->args)
 		goto errout;
-	}
+
 	for (i = 0; i < tev->nargs; i++)
 		copy_to_probe_trace_arg(&tev->args[i], &pev->args[i]);
 
 	return 1;
 
 errout:
-	if (*tevs) {
-		clear_probe_trace_events(*tevs, 1);
-		*tevs = NULL;
-	}
+	clear_probe_trace_events(*tevs, 1);
+	*tevs = NULL;
 	return err;
 }
 
diff --git a/tools/perf/util/scripting-engines/trace-event-perl.c b/tools/perf/util/scripting-engines/trace-event-perl.c
index e55a132f69b7..014ecd6f67c4 100644
--- a/tools/perf/util/scripting-engines/trace-event-perl.c
+++ b/tools/perf/util/scripting-engines/trace-event-perl.c
@@ -350,8 +350,10 @@ static void perl_process_tracepoint(struct perf_sample *sample,
 	if (evsel->attr.type != PERF_TYPE_TRACEPOINT)
 		return;
 
-	if (!event)
-		die("ug! no event found for type %" PRIu64, (u64)evsel->attr.config);
+	if (!event) {
+		pr_debug("ug! no event found for type %" PRIu64, (u64)evsel->attr.config);
+		return;
+	}
 
 	pid = raw_field_value(event, "common_pid", data);
 
diff --git a/tools/perf/util/trace-event-info.c b/tools/perf/util/trace-event-info.c
index d995743cb673..ceb0e2720223 100644
--- a/tools/perf/util/trace-event-info.c
+++ b/tools/perf/util/trace-event-info.c
@@ -42,7 +42,7 @@
 #include "evsel.h"
 #include "debug.h"
 
-#define VERSION "0.5"
+#define VERSION "0.6"
 
 static int output_fd;
 
@@ -379,6 +379,34 @@ out:
 	return err;
 }
 
+static int record_saved_cmdline(void)
+{
+	unsigned int size;
+	char *path;
+	struct stat st;
+	int ret, err = 0;
+
+	path = get_tracing_file("saved_cmdlines");
+	if (!path) {
+		pr_debug("can't get tracing/saved_cmdline");
+		return -ENOMEM;
+	}
+
+	ret = stat(path, &st);
+	if (ret < 0) {
+		/* not found */
+		size = 0;
+		if (write(output_fd, &size, 8) != 8)
+			err = -EIO;
+		goto out;
+	}
+	err = record_file(path, 8);
+
+out:
+	put_tracing_file(path);
+	return err;
+}
+
 static void
 put_tracepoints_path(struct tracepoint_path *tps)
 {
@@ -539,6 +567,9 @@ struct tracing_data *tracing_data_get(struct list_head *pattrs,
 	if (err)
 		goto out;
 	err = record_ftrace_printk();
+	if (err)
+		goto out;
+	err = record_saved_cmdline();
 
 out:
 	/*
diff --git a/tools/perf/util/trace-event-parse.c b/tools/perf/util/trace-event-parse.c
index 33b52eaa39db..de0078e21408 100644
--- a/tools/perf/util/trace-event-parse.c
+++ b/tools/perf/util/trace-event-parse.c
@@ -160,6 +160,23 @@ void parse_ftrace_printk(struct pevent *pevent,
 	}
 }
 
+void parse_saved_cmdline(struct pevent *pevent,
+			 char *file, unsigned int size __maybe_unused)
+{
+	char *comm;
+	char *line;
+	char *next = NULL;
+	int pid;
+
+	line = strtok_r(file, "\n", &next);
+	while (line) {
+		sscanf(line, "%d %ms", &pid, &comm);
+		pevent_register_comm(pevent, comm, pid);
+		free(comm);
+		line = strtok_r(NULL, "\n", &next);
+	}
+}
+
 int parse_ftrace_file(struct pevent *pevent, char *buf, unsigned long size)
 {
 	return pevent_parse_event(pevent, buf, size, "ftrace");
diff --git a/tools/perf/util/trace-event-read.c b/tools/perf/util/trace-event-read.c
index b67a0ccf5ab9..27420159bf69 100644
--- a/tools/perf/util/trace-event-read.c
+++ b/tools/perf/util/trace-event-read.c
@@ -260,39 +260,53 @@ static int read_header_files(struct pevent *pevent)
 
 static int read_ftrace_file(struct pevent *pevent, unsigned long long size)
 {
+	int ret;
 	char *buf;
 
 	buf = malloc(size);
-	if (buf == NULL)
+	if (buf == NULL) {
+		pr_debug("memory allocation failure\n");
 		return -1;
+	}
 
-	if (do_read(buf, size) < 0) {
-		free(buf);
-		return -1;
+	ret = do_read(buf, size);
+	if (ret < 0) {
+		pr_debug("error reading ftrace file.\n");
+		goto out;
 	}
 
-	parse_ftrace_file(pevent, buf, size);
+	ret = parse_ftrace_file(pevent, buf, size);
+	if (ret < 0)
+		pr_debug("error parsing ftrace file.\n");
+out:
 	free(buf);
-	return 0;
+	return ret;
 }
 
 static int read_event_file(struct pevent *pevent, char *sys,
 			    unsigned long long size)
 {
+	int ret;
 	char *buf;
 
 	buf = malloc(size);
-	if (buf == NULL)
+	if (buf == NULL) {
+		pr_debug("memory allocation failure\n");
 		return -1;
+	}
 
-	if (do_read(buf, size) < 0) {
+	ret = do_read(buf, size);
+	if (ret < 0) {
 		free(buf);
-		return -1;
+		goto out;
 	}
 
-	parse_event_file(pevent, buf, size, sys);
+	ret = parse_event_file(pevent, buf, size, sys);
+	if (ret < 0)
+		pr_debug("error parsing event file.\n");
+out:
 	free(buf);
-	return 0;
+	return ret;
 }
 
 static int read_ftrace_files(struct pevent *pevent)
@@ -341,6 +355,36 @@ static int read_event_files(struct pevent *pevent)
 	return 0;
 }
 
+static int read_saved_cmdline(struct pevent *pevent)
+{
+	unsigned long long size;
+	char *buf;
+	int ret;
+
+	/* it can have 0 size */
+	size = read8(pevent);
+	if (!size)
+		return 0;
+
+	buf = malloc(size + 1);
+	if (buf == NULL) {
+		pr_debug("memory allocation failure\n");
+		return -1;
+	}
+
+	ret = do_read(buf, size);
+	if (ret < 0) {
+		pr_debug("error reading saved cmdlines\n");
+		goto out;
+	}
+
+	parse_saved_cmdline(pevent, buf, size);
+	ret = 0;
+out:
+	free(buf);
+	return ret;
+}
+
 ssize_t trace_report(int fd, struct trace_event *tevent, bool __repipe)
 {
 	char buf[BUFSIZ];
@@ -379,10 +423,11 @@ ssize_t trace_report(int fd, struct trace_event *tevent, bool __repipe)
 		return -1;
 	if (show_version)
 		printf("version = %s\n", version);
-	free(version);
 
-	if (do_read(buf, 1) < 0)
+	if (do_read(buf, 1) < 0) {
+		free(version);
 		return -1;
+	}
 	file_bigendian = buf[0];
 	host_bigendian = bigendian();
 
@@ -423,6 +468,11 @@ ssize_t trace_report(int fd, struct trace_event *tevent, bool __repipe)
 	err = read_ftrace_printk(pevent);
 	if (err)
 		goto out;
+	if (atof(version) >= 0.6) {
+		err = read_saved_cmdline(pevent);
+		if (err)
+			goto out;
+	}
 
 	size = trace_data_size;
 	repipe = false;
@@ -438,5 +488,6 @@ ssize_t trace_report(int fd, struct trace_event *tevent, bool __repipe)
 out:
 	if (pevent)
 		trace_event__cleanup(tevent);
+	free(version);
 	return size;
 }
diff --git a/tools/perf/util/trace-event.h b/tools/perf/util/trace-event.h
index b0af9c81bb0d..1fbc044f9eb0 100644
--- a/tools/perf/util/trace-event.h
+++ b/tools/perf/util/trace-event.h
@@ -42,6 +42,7 @@ raw_field_value(struct event_format *event, const char *name, void *data);
 
 void parse_proc_kallsyms(struct pevent *pevent, char *file, unsigned int size);
 void parse_ftrace_printk(struct pevent *pevent, char *file, unsigned int size);
+void parse_saved_cmdline(struct pevent *pevent, char *file, unsigned int size);
 
 ssize_t trace_report(int fd, struct trace_event *tevent, bool repipe);
 
diff --git a/tools/perf/util/unwind-libunwind-local.c b/tools/perf/util/unwind-libunwind-local.c
index 6fec84dff3f7..bfb9b7987692 100644
--- a/tools/perf/util/unwind-libunwind-local.c
+++ b/tools/perf/util/unwind-libunwind-local.c
@@ -35,6 +35,7 @@
 #include "util.h"
 #include "debug.h"
 #include "asm/bug.h"
+#include "dso.h"
 
 extern int
 UNW_OBJ(dwarf_search_unwind_table) (unw_addr_space_t as,
@@ -297,15 +298,58 @@ static int read_unwind_spec_debug_frame(struct dso *dso,
 	int fd;
 	u64 ofs = dso->data.debug_frame_offset;
 
+	/* debug_frame can reside in:
+	 *  - dso
+	 *  - debug pointed by symsrc_filename
+	 *  - gnu_debuglink, which doesn't necessary
+	 *    has to be pointed by symsrc_filename
+	 */
 	if (ofs == 0) {
 		fd = dso__data_get_fd(dso, machine);
-		if (fd < 0)
-			return -EINVAL;
+		if (fd >= 0) {
+			ofs = elf_section_offset(fd, ".debug_frame");
+			dso__data_put_fd(dso);
+		}
+
+		if (ofs <= 0) {
+			fd = open(dso->symsrc_filename, O_RDONLY);
+			if (fd >= 0) {
+				ofs = elf_section_offset(fd, ".debug_frame");
+				close(fd);
+			}
+		}
+
+		if (ofs <= 0) {
+			char *debuglink = malloc(PATH_MAX);
+			int ret = 0;
+
+			ret = dso__read_binary_type_filename(
+				dso, DSO_BINARY_TYPE__DEBUGLINK,
+				machine->root_dir, debuglink, PATH_MAX);
+			if (!ret) {
+				fd = open(debuglink, O_RDONLY);
+				if (fd >= 0) {
+					ofs = elf_section_offset(fd,
+							".debug_frame");
+					close(fd);
+				}
+			}
+			if (ofs > 0) {
+				if (dso->symsrc_filename != NULL) {
+					pr_warning(
+						"%s: overwrite symsrc(%s,%s)\n",
+							__func__,
+							dso->symsrc_filename,
+							debuglink);
+					free(dso->symsrc_filename);
+				}
+				dso->symsrc_filename = debuglink;
+			} else {
+				free(debuglink);
+			}
+		}
 
-		/* Check the .debug_frame section for unwinding info */
-		ofs = elf_section_offset(fd, ".debug_frame");
 		dso->data.debug_frame_offset = ofs;
-		dso__data_put_fd(dso);
 	}
 
 	*offset = ofs;