[linux-2.6-block.git] / tools / perf / builtin-ftrace.c

/*
 * builtin-ftrace.c
 *
 * Copyright (c) 2013  LG Electronics,  Namhyung Kim <namhyung@kernel.org>
 *
 * Released under the GPL v2.
 */

#include "builtin.h"
#include "perf.h"

#include <errno.h>
#include <unistd.h>
#include <signal.h>
#include <fcntl.h>
#include <poll.h>

#include "debug.h"
#include <subcmd/parse-options.h>
#include <api/fs/tracing_path.h>
#include "evlist.h"
#include "target.h"
#include "cpumap.h"
#include "thread_map.h"
#include "util/config.h"


#define DEFAULT_TRACER  "function_graph"

struct perf_ftrace {
	struct perf_evlist	*evlist;
	struct target		target;
	const char		*tracer;
	struct list_head	filters;
	struct list_head	notrace;
	struct list_head	graph_funcs;
	struct list_head	nograph_funcs;
	int			graph_depth;
};

struct filter_entry {
	struct list_head	list;
	char			name[];
};

static bool done;

static void sig_handler(int sig __maybe_unused)
{
	done = true;
}

/*
 * perf_evlist__prepare_workload will send a SIGUSR1 if the fork fails, since
 * we asked by setting its exec_error to the function below,
 * ftrace__workload_exec_failed_signal.
 *
 * XXX We need to handle this more appropriately, emitting an error, etc.
 */
static void ftrace__workload_exec_failed_signal(int signo __maybe_unused,
						siginfo_t *info __maybe_unused,
						void *ucontext __maybe_unused)
{
	/* workload_exec_errno = info->si_value.sival_int; */
	done = true;
}

static int __write_tracing_file(const char *name, const char *val, bool append)
{
	char *file;
	int fd, ret = -1;
	ssize_t size = strlen(val);
	int flags = O_WRONLY;
	char errbuf[512];
	char *val_copy;

	file = get_tracing_file(name);
	if (!file) {
		pr_debug("cannot get tracing file: %s\n", name);
		return -1;
	}

	if (append)
		flags |= O_APPEND;
	else
		flags |= O_TRUNC;

	fd = open(file, flags);
	if (fd < 0) {
		pr_debug("cannot open tracing file: %s: %s\n",
			 name, str_error_r(errno, errbuf, sizeof(errbuf)));
		goto out;
	}

	/*
	 * Copy the original value and append a '\n'. Without this,
	 * the kernel can hide possible errors.
	 */
	val_copy = strdup(val);
	if (!val_copy)
		goto out_close;
	val_copy[size] = '\n';

	if (write(fd, val_copy, size + 1) == size + 1)
		ret = 0;
	else
		pr_debug("write '%s' to tracing/%s failed: %s\n",
			 val, name, str_error_r(errno, errbuf, sizeof(errbuf)));

	free(val_copy);
out_close:
	close(fd);
out:
	put_tracing_file(file);
	return ret;
}

static int write_tracing_file(const char *name, const char *val)
{
	return __write_tracing_file(name, val, false);
}

static int append_tracing_file(const char *name, const char *val)
{
	return __write_tracing_file(name, val, true);
}

static int reset_tracing_cpu(void);
static void reset_tracing_filters(void);

static int reset_tracing_files(struct perf_ftrace *ftrace __maybe_unused)
{
	if (write_tracing_file("tracing_on", "0") < 0)
		return -1;

	if (write_tracing_file("current_tracer", "nop") < 0)
		return -1;

	if (write_tracing_file("set_ftrace_pid", " ") < 0)
		return -1;

	if (reset_tracing_cpu() < 0)
		return -1;

	if (write_tracing_file("max_graph_depth", "0") < 0)
		return -1;

	reset_tracing_filters();
	return 0;
}

static int set_tracing_pid(struct perf_ftrace *ftrace)
{
	int i;
	char buf[16];

	if (target__has_cpu(&ftrace->target))
		return 0;

	for (i = 0; i < thread_map__nr(ftrace->evlist->threads); i++) {
		scnprintf(buf, sizeof(buf), "%d",
			  ftrace->evlist->threads->map[i]);
		if (append_tracing_file("set_ftrace_pid", buf) < 0)
			return -1;
	}
	return 0;
}

static int set_tracing_cpumask(struct cpu_map *cpumap)
{
	char *cpumask;
	size_t mask_size;
	int ret;
	int last_cpu;

	last_cpu = cpu_map__cpu(cpumap, cpumap->nr - 1);
	mask_size = (last_cpu + 3) / 4 + 1;
	mask_size += last_cpu / 32; /* ',' is needed for every 32th cpus */

	cpumask = malloc(mask_size);
	if (cpumask == NULL) {
		pr_debug("failed to allocate cpu mask\n");
		return -1;
	}

	cpu_map__snprint_mask(cpumap, cpumask, mask_size);

	ret = write_tracing_file("tracing_cpumask", cpumask);

	free(cpumask);
	return ret;
}

static int set_tracing_cpu(struct perf_ftrace *ftrace)
{
	struct cpu_map *cpumap = ftrace->evlist->cpus;

	if (!target__has_cpu(&ftrace->target))
		return 0;

	return set_tracing_cpumask(cpumap);
}

static int reset_tracing_cpu(void)
{
	struct cpu_map *cpumap = cpu_map__new(NULL);
	int ret;

	ret = set_tracing_cpumask(cpumap);
	cpu_map__put(cpumap);
	return ret;
}

static int __set_tracing_filter(const char *filter_file, struct list_head *funcs)
{
	struct filter_entry *pos;

	list_for_each_entry(pos, funcs, list) {
		if (append_tracing_file(filter_file, pos->name) < 0)
			return -1;
	}

	return 0;
}

static int set_tracing_filters(struct perf_ftrace *ftrace)
{
	int ret;

	ret = __set_tracing_filter("set_ftrace_filter", &ftrace->filters);
	if (ret < 0)
		return ret;

	ret = __set_tracing_filter("set_ftrace_notrace", &ftrace->notrace);
	if (ret < 0)
		return ret;

	ret = __set_tracing_filter("set_graph_function", &ftrace->graph_funcs);
	if (ret < 0)
		return ret;

	/* old kernels do not have this filter */
	__set_tracing_filter("set_graph_notrace", &ftrace->nograph_funcs);

	return ret;
}

static void reset_tracing_filters(void)
{
	write_tracing_file("set_ftrace_filter", " ");
	write_tracing_file("set_ftrace_notrace", " ");
	write_tracing_file("set_graph_function", " ");
	write_tracing_file("set_graph_notrace", " ");
}

static int set_tracing_depth(struct perf_ftrace *ftrace)
{
	char buf[16];

	if (ftrace->graph_depth == 0)
		return 0;

	if (ftrace->graph_depth < 0) {
		pr_err("invalid graph depth: %d\n", ftrace->graph_depth);
		return -1;
	}

	snprintf(buf, sizeof(buf), "%d", ftrace->graph_depth);

	if (write_tracing_file("max_graph_depth", buf) < 0)
		return -1;

	return 0;
}

static int __cmd_ftrace(struct perf_ftrace *ftrace, int argc, const char **argv)
{
	char *trace_file;
	int trace_fd;
	char buf[4096];
	struct pollfd pollfd = {
		.events = POLLIN,
	};

	if (geteuid() != 0) {
		pr_err("ftrace only works for root!\n");
		return -1;
	}

	signal(SIGINT, sig_handler);
	signal(SIGUSR1, sig_handler);
	signal(SIGCHLD, sig_handler);
	signal(SIGPIPE, sig_handler);

	if (reset_tracing_files(ftrace) < 0) {
		pr_err("failed to reset ftrace\n");
		goto out;
	}

	/* reset ftrace buffer */
	if (write_tracing_file("trace", "0") < 0)
		goto out;

	if (argc && perf_evlist__prepare_workload(ftrace->evlist,
				&ftrace->target, argv, false,
				ftrace__workload_exec_failed_signal) < 0) {
		goto out;
	}

	if (set_tracing_pid(ftrace) < 0) {
		pr_err("failed to set ftrace pid\n");
		goto out_reset;
	}

	if (set_tracing_cpu(ftrace) < 0) {
		pr_err("failed to set tracing cpumask\n");
		goto out_reset;
	}

	if (set_tracing_filters(ftrace) < 0) {
		pr_err("failed to set tracing filters\n");
		goto out_reset;
	}

	if (set_tracing_depth(ftrace) < 0) {
		pr_err("failed to set graph depth\n");
		goto out_reset;
	}

	if (write_tracing_file("current_tracer", ftrace->tracer) < 0) {
		pr_err("failed to set current_tracer to %s\n", ftrace->tracer);
		goto out_reset;
	}

	setup_pager();

	trace_file = get_tracing_file("trace_pipe");
	if (!trace_file) {
		pr_err("failed to open trace_pipe\n");
		goto out_reset;
	}

	trace_fd = open(trace_file, O_RDONLY);

	put_tracing_file(trace_file);

	if (trace_fd < 0) {
		pr_err("failed to open trace_pipe\n");
		goto out_reset;
	}

	fcntl(trace_fd, F_SETFL, O_NONBLOCK);
	pollfd.fd = trace_fd;

	if (write_tracing_file("tracing_on", "1") < 0) {
		pr_err("can't enable tracing\n");
		goto out_close_fd;
	}

	perf_evlist__start_workload(ftrace->evlist);

	while (!done) {
		if (poll(&pollfd, 1, -1) < 0)
			break;

		if (pollfd.revents & POLLIN) {
			int n = read(trace_fd, buf, sizeof(buf));
			if (n < 0)
				break;
			if (fwrite(buf, n, 1, stdout) != 1)
				break;
		}
	}

	write_tracing_file("tracing_on", "0");

	/* read remaining buffer contents */
	while (true) {
		int n = read(trace_fd, buf, sizeof(buf));
		if (n <= 0)
			break;
		if (fwrite(buf, n, 1, stdout) != 1)
			break;
	}

out_close_fd:
	close(trace_fd);
out_reset:
	reset_tracing_files(ftrace);
out:
	return done ? 0 : -1;
}

static int perf_ftrace_config(const char *var, const char *value, void *cb)
{
	struct perf_ftrace *ftrace = cb;

	if (!strstarts(var, "ftrace."))
		return 0;

	if (strcmp(var, "ftrace.tracer"))
		return -1;

	if (!strcmp(value, "function_graph") ||
	    !strcmp(value, "function")) {
		ftrace->tracer = value;
		return 0;
	}

	pr_err("Please select \"function_graph\" (default) or \"function\"\n");
	return -1;
}

static int parse_filter_func(const struct option *opt, const char *str,
			     int unset __maybe_unused)
{
	struct list_head *head = opt->value;
	struct filter_entry *entry;

	entry = malloc(sizeof(*entry) + strlen(str) + 1);
	if (entry == NULL)
		return -ENOMEM;

	strcpy(entry->name, str);
	list_add_tail(&entry->list, head);

	return 0;
}

static void delete_filter_func(struct list_head *head)
{
	struct filter_entry *pos, *tmp;

	list_for_each_entry_safe(pos, tmp, head, list) {
		list_del(&pos->list);
		free(pos);
	}
}

int cmd_ftrace(int argc, const char **argv)
{
	int ret;
	struct perf_ftrace ftrace = {
		.tracer = DEFAULT_TRACER,
		.target = { .uid = UINT_MAX, },
	};
	const char * const ftrace_usage[] = {
		"perf ftrace [<options>] [<command>]",
		"perf ftrace [<options>] -- <command> [<options>]",
		NULL
	};
	const struct option ftrace_options[] = {
	OPT_STRING('t', "tracer", &ftrace.tracer, "tracer",
		   "tracer to use: function_graph(default) or function"),
	OPT_STRING('p', "pid", &ftrace.target.pid, "pid",
		   "trace on existing process id"),
	OPT_INCR('v', "verbose", &verbose,
		 "be more verbose"),
	OPT_BOOLEAN('a', "all-cpus", &ftrace.target.system_wide,
		    "system-wide collection from all CPUs"),
	OPT_STRING('C', "cpu", &ftrace.target.cpu_list, "cpu",
		    "list of cpus to monitor"),
	OPT_CALLBACK('T', "trace-funcs", &ftrace.filters, "func",
		     "trace given functions only", parse_filter_func),
	OPT_CALLBACK('N', "notrace-funcs", &ftrace.notrace, "func",
		     "do not trace given functions", parse_filter_func),
	OPT_CALLBACK('G', "graph-funcs", &ftrace.graph_funcs, "func",
		     "Set graph filter on given functions", parse_filter_func),
	OPT_CALLBACK('g', "nograph-funcs", &ftrace.nograph_funcs, "func",
		     "Set nograph filter on given functions", parse_filter_func),
	OPT_INTEGER('D', "graph-depth", &ftrace.graph_depth,
		    "Max depth for function graph tracer"),
	OPT_END()
	};

	INIT_LIST_HEAD(&ftrace.filters);
	INIT_LIST_HEAD(&ftrace.notrace);
	INIT_LIST_HEAD(&ftrace.graph_funcs);
	INIT_LIST_HEAD(&ftrace.nograph_funcs);

	ret = perf_config(perf_ftrace_config, &ftrace);
	if (ret < 0)
		return -1;

	argc = parse_options(argc, argv, ftrace_options, ftrace_usage,
			    PARSE_OPT_STOP_AT_NON_OPTION);
	if (!argc && target__none(&ftrace.target))
		usage_with_options(ftrace_usage, ftrace_options);

	ret = target__validate(&ftrace.target);
	if (ret) {
		char errbuf[512];

		target__strerror(&ftrace.target, ret, errbuf, 512);
		pr_err("%s\n", errbuf);
		goto out_delete_filters;
	}

	ftrace.evlist = perf_evlist__new();
	if (ftrace.evlist == NULL) {
		ret = -ENOMEM;
		goto out_delete_filters;
	}

	ret = perf_evlist__create_maps(ftrace.evlist, &ftrace.target);
	if (ret < 0)
		goto out_delete_evlist;

	ret = __cmd_ftrace(&ftrace, argc, argv);

out_delete_evlist:
	perf_evlist__delete(ftrace.evlist);

out_delete_filters:
	delete_filter_func(&ftrace.filters);
	delete_filter_func(&ftrace.notrace);
	delete_filter_func(&ftrace.graph_funcs);
	delete_filter_func(&ftrace.nograph_funcs);

	return ret;
}
Commit	Line	Data
d01f4e8d NK	1	/*
	2	* builtin-ftrace.c
	3	*
	4	* Copyright (c) 2013 LG Electronics, Namhyung Kim <namhyung@kernel.org>
	5	*
	6	* Released under the GPL v2.
	7	*/
	8
	9	#include "builtin.h"
	10	#include "perf.h"
	11
a43783ae	12	#include <errno.h>
d01f4e8d NK	13	#include <unistd.h>
d01f4e8d NK	14	#include <signal.h>
a9af6be5	15	#include <fcntl.h>
4208735d	16	#include <poll.h>
d01f4e8d NK	17
	18	#include "debug.h"
	19	#include <subcmd/parse-options.h>
20a9ed28	20	#include <api/fs/tracing_path.h>
d01f4e8d NK	21	#include "evlist.h"
d01f4e8d NK	22	#include "target.h"
dc231032	23	#include "cpumap.h"
d01f4e8d	24	#include "thread_map.h"
b05d1093	25	#include "util/config.h"
d01f4e8d NK	26
	27
	28	#define DEFAULT_TRACER "function_graph"
	29
	30	struct perf_ftrace {
78b83e8b NK	31	struct perf_evlist *evlist;
	32	struct target target;
	33	const char *tracer;
	34	struct list_head filters;
	35	struct list_head notrace;
	36	struct list_head graph_funcs;
	37	struct list_head nograph_funcs;
1096c35a	38	int graph_depth;
78b83e8b NK	39	};
	40
	41	struct filter_entry {
	42	struct list_head list;
	43	char name[];
d01f4e8d NK	44	};
	45
	46	static bool done;
	47
	48	static void sig_handler(int sig __maybe_unused)
	49	{
	50	done = true;
	51	}
	52
	53	/*
	54	* perf_evlist__prepare_workload will send a SIGUSR1 if the fork fails, since
	55	* we asked by setting its exec_error to the function below,
	56	* ftrace__workload_exec_failed_signal.
	57	*
	58	* XXX We need to handle this more appropriately, emitting an error, etc.
	59	*/
	60	static void ftrace__workload_exec_failed_signal(int signo __maybe_unused,
	61	siginfo_t *info __maybe_unused,
	62	void *ucontext __maybe_unused)
	63	{
	64	/* workload_exec_errno = info->si_value.sival_int; */
	65	done = true;
	66	}
	67
a9af6be5	68	static int __write_tracing_file(const char name, const char val, bool append)
d01f4e8d NK	69	{
	70	char *file;
	71	int fd, ret = -1;
	72	ssize_t size = strlen(val);
a9af6be5	73	int flags = O_WRONLY;
e7bd9ba2	74	char errbuf[512];
63cd02d8	75	char *val_copy;
d01f4e8d NK	76
	77	file = get_tracing_file(name);
	78	if (!file) {
	79	pr_debug("cannot get tracing file: %s\n", name);
	80	return -1;
	81	}
	82
a9af6be5 NK	83	if (append)
	84	flags \|= O_APPEND;
	85	else
	86	flags \|= O_TRUNC;
	87
	88	fd = open(file, flags);
d01f4e8d	89	if (fd < 0) {
e7bd9ba2 NK	90	pr_debug("cannot open tracing file: %s: %s\n",
e7bd9ba2 NK	91	name, str_error_r(errno, errbuf, sizeof(errbuf)));
d01f4e8d NK	92	goto out;
	93	}
	94
63cd02d8 CD	95	/*
	96	* Copy the original value and append a '\n'. Without this,
	97	* the kernel can hide possible errors.
	98	*/
	99	val_copy = strdup(val);
	100	if (!val_copy)
	101	goto out_close;
	102	val_copy[size] = '\n';
	103
	104	if (write(fd, val_copy, size + 1) == size + 1)
d01f4e8d NK	105	ret = 0;
d01f4e8d NK	106	else
e7bd9ba2 NK	107	pr_debug("write '%s' to tracing/%s failed: %s\n",
e7bd9ba2 NK	108	val, name, str_error_r(errno, errbuf, sizeof(errbuf)));
d01f4e8d	109
63cd02d8 CD	110	free(val_copy);
63cd02d8 CD	111	out_close:
d01f4e8d NK	112	close(fd);
	113	out:
	114	put_tracing_file(file);
	115	return ret;
	116	}
	117
a9af6be5 NK	118	static int write_tracing_file(const char name, const char val)
	119	{
	120	return __write_tracing_file(name, val, false);
	121	}
	122
	123	static int append_tracing_file(const char name, const char val)
	124	{
	125	return __write_tracing_file(name, val, true);
	126	}
	127
dc231032	128	static int reset_tracing_cpu(void);
78b83e8b	129	static void reset_tracing_filters(void);
dc231032	130
d01f4e8d NK	131	static int reset_tracing_files(struct perf_ftrace *ftrace __maybe_unused)
	132	{
	133	if (write_tracing_file("tracing_on", "0") < 0)
	134	return -1;
	135
	136	if (write_tracing_file("current_tracer", "nop") < 0)
	137	return -1;
	138
	139	if (write_tracing_file("set_ftrace_pid", " ") < 0)
	140	return -1;
	141
dc231032 NK	142	if (reset_tracing_cpu() < 0)
	143	return -1;
	144
1096c35a NK	145	if (write_tracing_file("max_graph_depth", "0") < 0)
	146	return -1;
	147
78b83e8b	148	reset_tracing_filters();
d01f4e8d NK	149	return 0;
	150	}
	151
a9af6be5 NK	152	static int set_tracing_pid(struct perf_ftrace *ftrace)
	153	{
	154	int i;
	155	char buf[16];
	156
	157	if (target__has_cpu(&ftrace->target))
	158	return 0;
	159
	160	for (i = 0; i < thread_map__nr(ftrace->evlist->threads); i++) {
	161	scnprintf(buf, sizeof(buf), "%d",
	162	ftrace->evlist->threads->map[i]);
	163	if (append_tracing_file("set_ftrace_pid", buf) < 0)
	164	return -1;
	165	}
	166	return 0;
	167	}
	168
dc231032 NK	169	static int set_tracing_cpumask(struct cpu_map *cpumap)
	170	{
	171	char *cpumask;
	172	size_t mask_size;
	173	int ret;
	174	int last_cpu;
	175
	176	last_cpu = cpu_map__cpu(cpumap, cpumap->nr - 1);
	177	mask_size = (last_cpu + 3) / 4 + 1;
	178	mask_size += last_cpu / 32; /* ',' is needed for every 32th cpus */
	179
	180	cpumask = malloc(mask_size);
	181	if (cpumask == NULL) {
	182	pr_debug("failed to allocate cpu mask\n");
	183	return -1;
	184	}
	185
	186	cpu_map__snprint_mask(cpumap, cpumask, mask_size);
	187
	188	ret = write_tracing_file("tracing_cpumask", cpumask);
	189
	190	free(cpumask);
	191	return ret;
	192	}
	193
	194	static int set_tracing_cpu(struct perf_ftrace *ftrace)
	195	{
	196	struct cpu_map *cpumap = ftrace->evlist->cpus;
	197
	198	if (!target__has_cpu(&ftrace->target))
	199	return 0;
	200
	201	return set_tracing_cpumask(cpumap);
	202	}
	203
	204	static int reset_tracing_cpu(void)
	205	{
	206	struct cpu_map *cpumap = cpu_map__new(NULL);
	207	int ret;
	208
	209	ret = set_tracing_cpumask(cpumap);
	210	cpu_map__put(cpumap);
	211	return ret;
	212	}
	213
78b83e8b NK	214	static int __set_tracing_filter(const char filter_file, struct list_head funcs)
	215	{
	216	struct filter_entry *pos;
	217
	218	list_for_each_entry(pos, funcs, list) {
	219	if (append_tracing_file(filter_file, pos->name) < 0)
	220	return -1;
	221	}
	222
	223	return 0;
	224	}
	225
	226	static int set_tracing_filters(struct perf_ftrace *ftrace)
	227	{
	228	int ret;
	229
	230	ret = __set_tracing_filter("set_ftrace_filter", &ftrace->filters);
	231	if (ret < 0)
	232	return ret;
	233
	234	ret = __set_tracing_filter("set_ftrace_notrace", &ftrace->notrace);
	235	if (ret < 0)
	236	return ret;
	237
	238	ret = __set_tracing_filter("set_graph_function", &ftrace->graph_funcs);
	239	if (ret < 0)
	240	return ret;
	241
	242	/* old kernels do not have this filter */
	243	__set_tracing_filter("set_graph_notrace", &ftrace->nograph_funcs);
	244
	245	return ret;
	246	}
	247
	248	static void reset_tracing_filters(void)
	249	{
	250	write_tracing_file("set_ftrace_filter", " ");
	251	write_tracing_file("set_ftrace_notrace", " ");
	252	write_tracing_file("set_graph_function", " ");
	253	write_tracing_file("set_graph_notrace", " ");
	254	}
	255
1096c35a NK	256	static int set_tracing_depth(struct perf_ftrace *ftrace)
	257	{
	258	char buf[16];
	259
	260	if (ftrace->graph_depth == 0)
	261	return 0;
	262
	263	if (ftrace->graph_depth < 0) {
	264	pr_err("invalid graph depth: %d\n", ftrace->graph_depth);
	265	return -1;
	266	}
	267
	268	snprintf(buf, sizeof(buf), "%d", ftrace->graph_depth);
	269
	270	if (write_tracing_file("max_graph_depth", buf) < 0)
	271	return -1;
	272
	273	return 0;
	274	}
	275
d01f4e8d NK	276	static int __cmd_ftrace(struct perf_ftrace ftrace, int argc, const char *argv)
	277	{
	278	char *trace_file;
	279	int trace_fd;
d01f4e8d NK	280	char buf[4096];
	281	struct pollfd pollfd = {
	282	.events = POLLIN,
	283	};
	284
	285	if (geteuid() != 0) {
	286	pr_err("ftrace only works for root!\n");
	287	return -1;
	288	}
	289
d01f4e8d NK	290	signal(SIGINT, sig_handler);
	291	signal(SIGUSR1, sig_handler);
	292	signal(SIGCHLD, sig_handler);
58335964	293	signal(SIGPIPE, sig_handler);
d01f4e8d	294
63cd02d8 CD	295	if (reset_tracing_files(ftrace) < 0) {
63cd02d8 CD	296	pr_err("failed to reset ftrace\n");
a9af6be5	297	goto out;
63cd02d8	298	}
d01f4e8d NK	299
	300	/* reset ftrace buffer */
	301	if (write_tracing_file("trace", "0") < 0)
	302	goto out;
	303
a9af6be5 NK	304	if (argc && perf_evlist__prepare_workload(ftrace->evlist,
	305	&ftrace->target, argv, false,
	306	ftrace__workload_exec_failed_signal) < 0) {
d01f4e8d NK	307	goto out;
	308	}
	309
a9af6be5 NK	310	if (set_tracing_pid(ftrace) < 0) {
	311	pr_err("failed to set ftrace pid\n");
	312	goto out_reset;
d01f4e8d NK	313	}
d01f4e8d NK	314
dc231032 NK	315	if (set_tracing_cpu(ftrace) < 0) {
	316	pr_err("failed to set tracing cpumask\n");
	317	goto out_reset;
	318	}
	319
78b83e8b NK	320	if (set_tracing_filters(ftrace) < 0) {
	321	pr_err("failed to set tracing filters\n");
	322	goto out_reset;
	323	}
	324
1096c35a NK	325	if (set_tracing_depth(ftrace) < 0) {
	326	pr_err("failed to set graph depth\n");
	327	goto out_reset;
	328	}
	329
a9af6be5 NK	330	if (write_tracing_file("current_tracer", ftrace->tracer) < 0) {
	331	pr_err("failed to set current_tracer to %s\n", ftrace->tracer);
	332	goto out_reset;
d01f4e8d NK	333	}
d01f4e8d NK	334
29681bc5 NK	335	setup_pager();
29681bc5 NK	336
d01f4e8d NK	337	trace_file = get_tracing_file("trace_pipe");
	338	if (!trace_file) {
	339	pr_err("failed to open trace_pipe\n");
a9af6be5	340	goto out_reset;
d01f4e8d NK	341	}
	342
	343	trace_fd = open(trace_file, O_RDONLY);
	344
	345	put_tracing_file(trace_file);
	346
	347	if (trace_fd < 0) {
	348	pr_err("failed to open trace_pipe\n");
a9af6be5	349	goto out_reset;
d01f4e8d NK	350	}
	351
	352	fcntl(trace_fd, F_SETFL, O_NONBLOCK);
	353	pollfd.fd = trace_fd;
	354
	355	if (write_tracing_file("tracing_on", "1") < 0) {
	356	pr_err("can't enable tracing\n");
	357	goto out_close_fd;
	358	}
	359
	360	perf_evlist__start_workload(ftrace->evlist);
	361
	362	while (!done) {
	363	if (poll(&pollfd, 1, -1) < 0)
	364	break;
	365
	366	if (pollfd.revents & POLLIN) {
	367	int n = read(trace_fd, buf, sizeof(buf));
	368	if (n < 0)
	369	break;
	370	if (fwrite(buf, n, 1, stdout) != 1)
	371	break;
	372	}
	373	}
	374
	375	write_tracing_file("tracing_on", "0");
	376
	377	/* read remaining buffer contents */
	378	while (true) {
	379	int n = read(trace_fd, buf, sizeof(buf));
	380	if (n <= 0)
	381	break;
	382	if (fwrite(buf, n, 1, stdout) != 1)
	383	break;
	384	}
	385
	386	out_close_fd:
	387	close(trace_fd);
a9af6be5	388	out_reset:
d01f4e8d	389	reset_tracing_files(ftrace);
a9af6be5	390	out:
d01f4e8d NK	391	return done ? 0 : -1;
	392	}
	393
b05d1093 TS	394	static int perf_ftrace_config(const char var, const char value, void *cb)
	395	{
	396	struct perf_ftrace *ftrace = cb;
	397
8e99b6d4	398	if (!strstarts(var, "ftrace."))
b05d1093 TS	399	return 0;
	400
	401	if (strcmp(var, "ftrace.tracer"))
	402	return -1;
	403
	404	if (!strcmp(value, "function_graph") \|\|
	405	!strcmp(value, "function")) {
	406	ftrace->tracer = value;
	407	return 0;
	408	}
	409
	410	pr_err("Please select \"function_graph\" (default) or \"function\"\n");
	411	return -1;
	412	}
	413
78b83e8b NK	414	static int parse_filter_func(const struct option opt, const char str,
	415	int unset __maybe_unused)
	416	{
	417	struct list_head *head = opt->value;
	418	struct filter_entry *entry;
	419
	420	entry = malloc(sizeof(*entry) + strlen(str) + 1);
	421	if (entry == NULL)
	422	return -ENOMEM;
	423
	424	strcpy(entry->name, str);
	425	list_add_tail(&entry->list, head);
	426
	427	return 0;
	428	}
	429
	430	static void delete_filter_func(struct list_head *head)
	431	{
	432	struct filter_entry pos, tmp;
	433
	434	list_for_each_entry_safe(pos, tmp, head, list) {
	435	list_del(&pos->list);
	436	free(pos);
	437	}
	438	}
	439
b0ad8ea6	440	int cmd_ftrace(int argc, const char **argv)
d01f4e8d NK	441	{
	442	int ret;
	443	struct perf_ftrace ftrace = {
bf062bd2	444	.tracer = DEFAULT_TRACER,
d01f4e8d NK	445	.target = { .uid = UINT_MAX, },
	446	};
	447	const char * const ftrace_usage[] = {
a9af6be5	448	"perf ftrace [<options>] [<command>]",
d01f4e8d NK	449	"perf ftrace [<options>] -- <command> [<options>]",
	450	NULL
	451	};
	452	const struct option ftrace_options[] = {
	453	OPT_STRING('t', "tracer", &ftrace.tracer, "tracer",
ec347870	454	"tracer to use: function_graph(default) or function"),
a9af6be5 NK	455	OPT_STRING('p', "pid", &ftrace.target.pid, "pid",
a9af6be5 NK	456	"trace on existing process id"),
d01f4e8d NK	457	OPT_INCR('v', "verbose", &verbose,
d01f4e8d NK	458	"be more verbose"),
dc231032 NK	459	OPT_BOOLEAN('a', "all-cpus", &ftrace.target.system_wide,
	460	"system-wide collection from all CPUs"),
	461	OPT_STRING('C', "cpu", &ftrace.target.cpu_list, "cpu",
	462	"list of cpus to monitor"),
78b83e8b NK	463	OPT_CALLBACK('T', "trace-funcs", &ftrace.filters, "func",
	464	"trace given functions only", parse_filter_func),
	465	OPT_CALLBACK('N', "notrace-funcs", &ftrace.notrace, "func",
	466	"do not trace given functions", parse_filter_func),
	467	OPT_CALLBACK('G', "graph-funcs", &ftrace.graph_funcs, "func",
	468	"Set graph filter on given functions", parse_filter_func),
	469	OPT_CALLBACK('g', "nograph-funcs", &ftrace.nograph_funcs, "func",
	470	"Set nograph filter on given functions", parse_filter_func),
1096c35a NK	471	OPT_INTEGER('D', "graph-depth", &ftrace.graph_depth,
1096c35a NK	472	"Max depth for function graph tracer"),
d01f4e8d NK	473	OPT_END()
	474	};
	475
78b83e8b NK	476	INIT_LIST_HEAD(&ftrace.filters);
	477	INIT_LIST_HEAD(&ftrace.notrace);
	478	INIT_LIST_HEAD(&ftrace.graph_funcs);
	479	INIT_LIST_HEAD(&ftrace.nograph_funcs);
	480
b05d1093 TS	481	ret = perf_config(perf_ftrace_config, &ftrace);
	482	if (ret < 0)
	483	return -1;
	484
d01f4e8d NK	485	argc = parse_options(argc, argv, ftrace_options, ftrace_usage,
d01f4e8d NK	486	PARSE_OPT_STOP_AT_NON_OPTION);
a9af6be5	487	if (!argc && target__none(&ftrace.target))
d01f4e8d NK	488	usage_with_options(ftrace_usage, ftrace_options);
d01f4e8d NK	489
a9af6be5 NK	490	ret = target__validate(&ftrace.target);
	491	if (ret) {
	492	char errbuf[512];
	493
	494	target__strerror(&ftrace.target, ret, errbuf, 512);
	495	pr_err("%s\n", errbuf);
78b83e8b	496	goto out_delete_filters;
a9af6be5 NK	497	}
a9af6be5 NK	498
d01f4e8d	499	ftrace.evlist = perf_evlist__new();
78b83e8b NK	500	if (ftrace.evlist == NULL) {
	501	ret = -ENOMEM;
	502	goto out_delete_filters;
	503	}
d01f4e8d NK	504
	505	ret = perf_evlist__create_maps(ftrace.evlist, &ftrace.target);
	506	if (ret < 0)
	507	goto out_delete_evlist;
	508
d01f4e8d NK	509	ret = __cmd_ftrace(&ftrace, argc, argv);
	510
	511	out_delete_evlist:
	512	perf_evlist__delete(ftrace.evlist);
	513
78b83e8b NK	514	out_delete_filters:
	515	delete_filter_func(&ftrace.filters);
	516	delete_filter_func(&ftrace.notrace);
	517	delete_filter_func(&ftrace.graph_funcs);
	518	delete_filter_func(&ftrace.nograph_funcs);
	519
d01f4e8d NK	520	return ret;
d01f4e8d NK	521	}