[people/arne_f/kernel.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];

	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;
	}

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

	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 / 4 + 2; /* one more byte for EOS */
	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)
		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];
d01f4e8d NK	75
	76	file = get_tracing_file(name);
	77	if (!file) {
	78	pr_debug("cannot get tracing file: %s\n", name);
	79	return -1;
	80	}
	81
a9af6be5 NK	82	if (append)
	83	flags \|= O_APPEND;
	84	else
	85	flags \|= O_TRUNC;
	86
	87	fd = open(file, flags);
d01f4e8d	88	if (fd < 0) {
e7bd9ba2 NK	89	pr_debug("cannot open tracing file: %s: %s\n",
e7bd9ba2 NK	90	name, str_error_r(errno, errbuf, sizeof(errbuf)));
d01f4e8d NK	91	goto out;
	92	}
	93
	94	if (write(fd, val, size) == size)
	95	ret = 0;
	96	else
e7bd9ba2 NK	97	pr_debug("write '%s' to tracing/%s failed: %s\n",
e7bd9ba2 NK	98	val, name, str_error_r(errno, errbuf, sizeof(errbuf)));
d01f4e8d NK	99
	100	close(fd);
	101	out:
	102	put_tracing_file(file);
	103	return ret;
	104	}
	105
a9af6be5 NK	106	static int write_tracing_file(const char name, const char val)
	107	{
	108	return __write_tracing_file(name, val, false);
	109	}
	110
	111	static int append_tracing_file(const char name, const char val)
	112	{
	113	return __write_tracing_file(name, val, true);
	114	}
	115
dc231032	116	static int reset_tracing_cpu(void);
78b83e8b	117	static void reset_tracing_filters(void);
dc231032	118
d01f4e8d NK	119	static int reset_tracing_files(struct perf_ftrace *ftrace __maybe_unused)
	120	{
	121	if (write_tracing_file("tracing_on", "0") < 0)
	122	return -1;
	123
	124	if (write_tracing_file("current_tracer", "nop") < 0)
	125	return -1;
	126
	127	if (write_tracing_file("set_ftrace_pid", " ") < 0)
	128	return -1;
	129
dc231032 NK	130	if (reset_tracing_cpu() < 0)
	131	return -1;
	132
1096c35a NK	133	if (write_tracing_file("max_graph_depth", "0") < 0)
	134	return -1;
	135
78b83e8b	136	reset_tracing_filters();
d01f4e8d NK	137	return 0;
	138	}
	139
a9af6be5 NK	140	static int set_tracing_pid(struct perf_ftrace *ftrace)
	141	{
	142	int i;
	143	char buf[16];
	144
	145	if (target__has_cpu(&ftrace->target))
	146	return 0;
	147
	148	for (i = 0; i < thread_map__nr(ftrace->evlist->threads); i++) {
	149	scnprintf(buf, sizeof(buf), "%d",
	150	ftrace->evlist->threads->map[i]);
	151	if (append_tracing_file("set_ftrace_pid", buf) < 0)
	152	return -1;
	153	}
	154	return 0;
	155	}
	156
dc231032 NK	157	static int set_tracing_cpumask(struct cpu_map *cpumap)
	158	{
	159	char *cpumask;
	160	size_t mask_size;
	161	int ret;
	162	int last_cpu;
	163
	164	last_cpu = cpu_map__cpu(cpumap, cpumap->nr - 1);
5411aefc	165	mask_size = last_cpu / 4 + 2; /* one more byte for EOS */
dc231032 NK	166	mask_size += last_cpu / 32; /* ',' is needed for every 32th cpus */
	167
	168	cpumask = malloc(mask_size);
	169	if (cpumask == NULL) {
	170	pr_debug("failed to allocate cpu mask\n");
	171	return -1;
	172	}
	173
	174	cpu_map__snprint_mask(cpumap, cpumask, mask_size);
	175
	176	ret = write_tracing_file("tracing_cpumask", cpumask);
	177
	178	free(cpumask);
	179	return ret;
	180	}
	181
	182	static int set_tracing_cpu(struct perf_ftrace *ftrace)
	183	{
	184	struct cpu_map *cpumap = ftrace->evlist->cpus;
	185
	186	if (!target__has_cpu(&ftrace->target))
	187	return 0;
	188
	189	return set_tracing_cpumask(cpumap);
	190	}
	191
	192	static int reset_tracing_cpu(void)
	193	{
	194	struct cpu_map *cpumap = cpu_map__new(NULL);
	195	int ret;
	196
	197	ret = set_tracing_cpumask(cpumap);
	198	cpu_map__put(cpumap);
	199	return ret;
	200	}
	201
78b83e8b NK	202	static int __set_tracing_filter(const char filter_file, struct list_head funcs)
	203	{
	204	struct filter_entry *pos;
	205
	206	list_for_each_entry(pos, funcs, list) {
	207	if (append_tracing_file(filter_file, pos->name) < 0)
	208	return -1;
	209	}
	210
	211	return 0;
	212	}
	213
	214	static int set_tracing_filters(struct perf_ftrace *ftrace)
	215	{
	216	int ret;
	217
	218	ret = __set_tracing_filter("set_ftrace_filter", &ftrace->filters);
	219	if (ret < 0)
	220	return ret;
	221
	222	ret = __set_tracing_filter("set_ftrace_notrace", &ftrace->notrace);
	223	if (ret < 0)
	224	return ret;
	225
	226	ret = __set_tracing_filter("set_graph_function", &ftrace->graph_funcs);
	227	if (ret < 0)
	228	return ret;
	229
	230	/* old kernels do not have this filter */
	231	__set_tracing_filter("set_graph_notrace", &ftrace->nograph_funcs);
	232
	233	return ret;
	234	}
	235
	236	static void reset_tracing_filters(void)
	237	{
	238	write_tracing_file("set_ftrace_filter", " ");
	239	write_tracing_file("set_ftrace_notrace", " ");
	240	write_tracing_file("set_graph_function", " ");
	241	write_tracing_file("set_graph_notrace", " ");
	242	}
	243
1096c35a NK	244	static int set_tracing_depth(struct perf_ftrace *ftrace)
	245	{
	246	char buf[16];
	247
	248	if (ftrace->graph_depth == 0)
	249	return 0;
	250
	251	if (ftrace->graph_depth < 0) {
	252	pr_err("invalid graph depth: %d\n", ftrace->graph_depth);
	253	return -1;
	254	}
	255
	256	snprintf(buf, sizeof(buf), "%d", ftrace->graph_depth);
	257
	258	if (write_tracing_file("max_graph_depth", buf) < 0)
	259	return -1;
	260
	261	return 0;
	262	}
	263
d01f4e8d NK	264	static int __cmd_ftrace(struct perf_ftrace ftrace, int argc, const char *argv)
	265	{
	266	char *trace_file;
	267	int trace_fd;
d01f4e8d NK	268	char buf[4096];
	269	struct pollfd pollfd = {
	270	.events = POLLIN,
	271	};
	272
	273	if (geteuid() != 0) {
	274	pr_err("ftrace only works for root!\n");
	275	return -1;
	276	}
	277
d01f4e8d NK	278	signal(SIGINT, sig_handler);
	279	signal(SIGUSR1, sig_handler);
	280	signal(SIGCHLD, sig_handler);
58335964	281	signal(SIGPIPE, sig_handler);
d01f4e8d	282
a9af6be5 NK	283	if (reset_tracing_files(ftrace) < 0)
a9af6be5 NK	284	goto out;
d01f4e8d NK	285
	286	/* reset ftrace buffer */
	287	if (write_tracing_file("trace", "0") < 0)
	288	goto out;
	289
a9af6be5 NK	290	if (argc && perf_evlist__prepare_workload(ftrace->evlist,
	291	&ftrace->target, argv, false,
	292	ftrace__workload_exec_failed_signal) < 0) {
d01f4e8d NK	293	goto out;
	294	}
	295
a9af6be5 NK	296	if (set_tracing_pid(ftrace) < 0) {
	297	pr_err("failed to set ftrace pid\n");
	298	goto out_reset;
d01f4e8d NK	299	}
d01f4e8d NK	300
dc231032 NK	301	if (set_tracing_cpu(ftrace) < 0) {
	302	pr_err("failed to set tracing cpumask\n");
	303	goto out_reset;
	304	}
	305
78b83e8b NK	306	if (set_tracing_filters(ftrace) < 0) {
	307	pr_err("failed to set tracing filters\n");
	308	goto out_reset;
	309	}
	310
1096c35a NK	311	if (set_tracing_depth(ftrace) < 0) {
	312	pr_err("failed to set graph depth\n");
	313	goto out_reset;
	314	}
	315
a9af6be5 NK	316	if (write_tracing_file("current_tracer", ftrace->tracer) < 0) {
	317	pr_err("failed to set current_tracer to %s\n", ftrace->tracer);
	318	goto out_reset;
d01f4e8d NK	319	}
d01f4e8d NK	320
29681bc5 NK	321	setup_pager();
29681bc5 NK	322
d01f4e8d NK	323	trace_file = get_tracing_file("trace_pipe");
	324	if (!trace_file) {
	325	pr_err("failed to open trace_pipe\n");
a9af6be5	326	goto out_reset;
d01f4e8d NK	327	}
	328
	329	trace_fd = open(trace_file, O_RDONLY);
	330
	331	put_tracing_file(trace_file);
	332
	333	if (trace_fd < 0) {
	334	pr_err("failed to open trace_pipe\n");
a9af6be5	335	goto out_reset;
d01f4e8d NK	336	}
	337
	338	fcntl(trace_fd, F_SETFL, O_NONBLOCK);
	339	pollfd.fd = trace_fd;
	340
	341	if (write_tracing_file("tracing_on", "1") < 0) {
	342	pr_err("can't enable tracing\n");
	343	goto out_close_fd;
	344	}
	345
	346	perf_evlist__start_workload(ftrace->evlist);
	347
	348	while (!done) {
	349	if (poll(&pollfd, 1, -1) < 0)
	350	break;
	351
	352	if (pollfd.revents & POLLIN) {
	353	int n = read(trace_fd, buf, sizeof(buf));
	354	if (n < 0)
	355	break;
	356	if (fwrite(buf, n, 1, stdout) != 1)
	357	break;
	358	}
	359	}
	360
	361	write_tracing_file("tracing_on", "0");
	362
	363	/* read remaining buffer contents */
	364	while (true) {
	365	int n = read(trace_fd, buf, sizeof(buf));
	366	if (n <= 0)
	367	break;
	368	if (fwrite(buf, n, 1, stdout) != 1)
	369	break;
	370	}
	371
	372	out_close_fd:
	373	close(trace_fd);
a9af6be5	374	out_reset:
d01f4e8d	375	reset_tracing_files(ftrace);
a9af6be5	376	out:
d01f4e8d NK	377	return done ? 0 : -1;
	378	}
	379
b05d1093 TS	380	static int perf_ftrace_config(const char var, const char value, void *cb)
	381	{
	382	struct perf_ftrace *ftrace = cb;
	383
8e99b6d4	384	if (!strstarts(var, "ftrace."))
b05d1093 TS	385	return 0;
	386
	387	if (strcmp(var, "ftrace.tracer"))
	388	return -1;
	389
	390	if (!strcmp(value, "function_graph") \|\|
	391	!strcmp(value, "function")) {
	392	ftrace->tracer = value;
	393	return 0;
	394	}
	395
	396	pr_err("Please select \"function_graph\" (default) or \"function\"\n");
	397	return -1;
	398	}
	399
78b83e8b NK	400	static int parse_filter_func(const struct option opt, const char str,
	401	int unset __maybe_unused)
	402	{
	403	struct list_head *head = opt->value;
	404	struct filter_entry *entry;
	405
	406	entry = malloc(sizeof(*entry) + strlen(str) + 1);
	407	if (entry == NULL)
	408	return -ENOMEM;
	409
	410	strcpy(entry->name, str);
	411	list_add_tail(&entry->list, head);
	412
	413	return 0;
	414	}
	415
	416	static void delete_filter_func(struct list_head *head)
	417	{
	418	struct filter_entry pos, tmp;
	419
	420	list_for_each_entry_safe(pos, tmp, head, list) {
	421	list_del(&pos->list);
	422	free(pos);
	423	}
	424	}
	425
b0ad8ea6	426	int cmd_ftrace(int argc, const char **argv)
d01f4e8d NK	427	{
	428	int ret;
	429	struct perf_ftrace ftrace = {
bf062bd2	430	.tracer = DEFAULT_TRACER,
d01f4e8d NK	431	.target = { .uid = UINT_MAX, },
	432	};
	433	const char * const ftrace_usage[] = {
a9af6be5	434	"perf ftrace [<options>] [<command>]",
d01f4e8d NK	435	"perf ftrace [<options>] -- <command> [<options>]",
	436	NULL
	437	};
	438	const struct option ftrace_options[] = {
	439	OPT_STRING('t', "tracer", &ftrace.tracer, "tracer",
ec347870	440	"tracer to use: function_graph(default) or function"),
a9af6be5 NK	441	OPT_STRING('p', "pid", &ftrace.target.pid, "pid",
a9af6be5 NK	442	"trace on existing process id"),
d01f4e8d NK	443	OPT_INCR('v', "verbose", &verbose,
d01f4e8d NK	444	"be more verbose"),
dc231032 NK	445	OPT_BOOLEAN('a', "all-cpus", &ftrace.target.system_wide,
	446	"system-wide collection from all CPUs"),
	447	OPT_STRING('C', "cpu", &ftrace.target.cpu_list, "cpu",
	448	"list of cpus to monitor"),
78b83e8b NK	449	OPT_CALLBACK('T', "trace-funcs", &ftrace.filters, "func",
	450	"trace given functions only", parse_filter_func),
	451	OPT_CALLBACK('N', "notrace-funcs", &ftrace.notrace, "func",
	452	"do not trace given functions", parse_filter_func),
	453	OPT_CALLBACK('G', "graph-funcs", &ftrace.graph_funcs, "func",
	454	"Set graph filter on given functions", parse_filter_func),
	455	OPT_CALLBACK('g', "nograph-funcs", &ftrace.nograph_funcs, "func",
	456	"Set nograph filter on given functions", parse_filter_func),
1096c35a NK	457	OPT_INTEGER('D', "graph-depth", &ftrace.graph_depth,
1096c35a NK	458	"Max depth for function graph tracer"),
d01f4e8d NK	459	OPT_END()
	460	};
	461
78b83e8b NK	462	INIT_LIST_HEAD(&ftrace.filters);
	463	INIT_LIST_HEAD(&ftrace.notrace);
	464	INIT_LIST_HEAD(&ftrace.graph_funcs);
	465	INIT_LIST_HEAD(&ftrace.nograph_funcs);
	466
b05d1093 TS	467	ret = perf_config(perf_ftrace_config, &ftrace);
	468	if (ret < 0)
	469	return -1;
	470
d01f4e8d NK	471	argc = parse_options(argc, argv, ftrace_options, ftrace_usage,
d01f4e8d NK	472	PARSE_OPT_STOP_AT_NON_OPTION);
a9af6be5	473	if (!argc && target__none(&ftrace.target))
d01f4e8d NK	474	usage_with_options(ftrace_usage, ftrace_options);
d01f4e8d NK	475
a9af6be5 NK	476	ret = target__validate(&ftrace.target);
	477	if (ret) {
	478	char errbuf[512];
	479
	480	target__strerror(&ftrace.target, ret, errbuf, 512);
	481	pr_err("%s\n", errbuf);
78b83e8b	482	goto out_delete_filters;
a9af6be5 NK	483	}
a9af6be5 NK	484
d01f4e8d	485	ftrace.evlist = perf_evlist__new();
78b83e8b NK	486	if (ftrace.evlist == NULL) {
	487	ret = -ENOMEM;
	488	goto out_delete_filters;
	489	}
d01f4e8d NK	490
	491	ret = perf_evlist__create_maps(ftrace.evlist, &ftrace.target);
	492	if (ret < 0)
	493	goto out_delete_evlist;
	494
d01f4e8d NK	495	ret = __cmd_ftrace(&ftrace, argc, argv);
	496
	497	out_delete_evlist:
	498	perf_evlist__delete(ftrace.evlist);
	499
78b83e8b NK	500	out_delete_filters:
	501	delete_filter_func(&ftrace.filters);
	502	delete_filter_func(&ftrace.notrace);
	503	delete_filter_func(&ftrace.graph_funcs);
	504	delete_filter_func(&ftrace.nograph_funcs);
	505
d01f4e8d NK	506	return ret;
d01f4e8d NK	507	}