[mirror_ubuntu-jammy-kernel.git] / tools / perf / builtin-ftrace.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * builtin-ftrace.c
 *
 * Copyright (c) 2013  LG Electronics,  Namhyung Kim <namhyung@kernel.org>
 */

#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 perf_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 perf_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 perf_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_init(&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
1c6bec5b	1	// SPDX-License-Identifier: GPL-2.0-only
d01f4e8d NK	2	/*
	3	* builtin-ftrace.c
	4	*
	5	* Copyright (c) 2013 LG Electronics, Namhyung Kim <namhyung@kernel.org>
d01f4e8d NK	6	*/
	7
	8	#include "builtin.h"
	9	#include "perf.h"
	10
a43783ae	11	#include <errno.h>
d01f4e8d NK	12	#include <unistd.h>
d01f4e8d NK	13	#include <signal.h>
a9af6be5	14	#include <fcntl.h>
4208735d	15	#include <poll.h>
d01f4e8d NK	16
	17	#include "debug.h"
	18	#include <subcmd/parse-options.h>
20a9ed28	19	#include <api/fs/tracing_path.h>
d01f4e8d NK	20	#include "evlist.h"
d01f4e8d NK	21	#include "target.h"
dc231032	22	#include "cpumap.h"
d01f4e8d	23	#include "thread_map.h"
b05d1093	24	#include "util/config.h"
d01f4e8d NK	25
	26
	27	#define DEFAULT_TRACER "function_graph"
	28
	29	struct perf_ftrace {
78b83e8b NK	30	struct perf_evlist *evlist;
	31	struct target target;
	32	const char *tracer;
	33	struct list_head filters;
	34	struct list_head notrace;
	35	struct list_head graph_funcs;
	36	struct list_head nograph_funcs;
1096c35a	37	int graph_depth;
78b83e8b NK	38	};
	39
	40	struct filter_entry {
	41	struct list_head list;
	42	char name[];
d01f4e8d NK	43	};
	44
	45	static bool done;
	46
	47	static void sig_handler(int sig __maybe_unused)
	48	{
	49	done = true;
	50	}
	51
	52	/*
	53	* perf_evlist__prepare_workload will send a SIGUSR1 if the fork fails, since
	54	* we asked by setting its exec_error to the function below,
	55	* ftrace__workload_exec_failed_signal.
	56	*
	57	* XXX We need to handle this more appropriately, emitting an error, etc.
	58	*/
	59	static void ftrace__workload_exec_failed_signal(int signo __maybe_unused,
	60	siginfo_t *info __maybe_unused,
	61	void *ucontext __maybe_unused)
	62	{
	63	/* workload_exec_errno = info->si_value.sival_int; */
	64	done = true;
	65	}
	66
a9af6be5	67	static int __write_tracing_file(const char name, const char val, bool append)
d01f4e8d NK	68	{
	69	char *file;
	70	int fd, ret = -1;
	71	ssize_t size = strlen(val);
a9af6be5	72	int flags = O_WRONLY;
e7bd9ba2	73	char errbuf[512];
63cd02d8	74	char *val_copy;
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
63cd02d8 CD	94	/*
	95	* Copy the original value and append a '\n'. Without this,
	96	* the kernel can hide possible errors.
	97	*/
	98	val_copy = strdup(val);
	99	if (!val_copy)
	100	goto out_close;
	101	val_copy[size] = '\n';
	102
	103	if (write(fd, val_copy, size + 1) == size + 1)
d01f4e8d NK	104	ret = 0;
d01f4e8d NK	105	else
e7bd9ba2 NK	106	pr_debug("write '%s' to tracing/%s failed: %s\n",
e7bd9ba2 NK	107	val, name, str_error_r(errno, errbuf, sizeof(errbuf)));
d01f4e8d	108
63cd02d8 CD	109	free(val_copy);
63cd02d8 CD	110	out_close:
d01f4e8d NK	111	close(fd);
	112	out:
	113	put_tracing_file(file);
	114	return ret;
	115	}
	116
a9af6be5 NK	117	static int write_tracing_file(const char name, const char val)
	118	{
	119	return __write_tracing_file(name, val, false);
	120	}
	121
	122	static int append_tracing_file(const char name, const char val)
	123	{
	124	return __write_tracing_file(name, val, true);
	125	}
	126
dc231032	127	static int reset_tracing_cpu(void);
78b83e8b	128	static void reset_tracing_filters(void);
dc231032	129
d01f4e8d NK	130	static int reset_tracing_files(struct perf_ftrace *ftrace __maybe_unused)
	131	{
	132	if (write_tracing_file("tracing_on", "0") < 0)
	133	return -1;
	134
	135	if (write_tracing_file("current_tracer", "nop") < 0)
	136	return -1;
	137
	138	if (write_tracing_file("set_ftrace_pid", " ") < 0)
	139	return -1;
	140
dc231032 NK	141	if (reset_tracing_cpu() < 0)
	142	return -1;
	143
1096c35a NK	144	if (write_tracing_file("max_graph_depth", "0") < 0)
	145	return -1;
	146
78b83e8b	147	reset_tracing_filters();
d01f4e8d NK	148	return 0;
	149	}
	150
a9af6be5 NK	151	static int set_tracing_pid(struct perf_ftrace *ftrace)
	152	{
	153	int i;
	154	char buf[16];
	155
	156	if (target__has_cpu(&ftrace->target))
	157	return 0;
	158
	159	for (i = 0; i < thread_map__nr(ftrace->evlist->threads); i++) {
	160	scnprintf(buf, sizeof(buf), "%d",
	161	ftrace->evlist->threads->map[i]);
	162	if (append_tracing_file("set_ftrace_pid", buf) < 0)
	163	return -1;
	164	}
	165	return 0;
	166	}
	167
f854839b	168	static int set_tracing_cpumask(struct perf_cpu_map *cpumap)
dc231032 NK	169	{
	170	char *cpumask;
	171	size_t mask_size;
	172	int ret;
	173	int last_cpu;
	174
	175	last_cpu = cpu_map__cpu(cpumap, cpumap->nr - 1);
	176	mask_size = (last_cpu + 3) / 4 + 1;
	177	mask_size += last_cpu / 32; /* ',' is needed for every 32th cpus */
	178
	179	cpumask = malloc(mask_size);
	180	if (cpumask == NULL) {
	181	pr_debug("failed to allocate cpu mask\n");
	182	return -1;
	183	}
	184
	185	cpu_map__snprint_mask(cpumap, cpumask, mask_size);
	186
	187	ret = write_tracing_file("tracing_cpumask", cpumask);
	188
	189	free(cpumask);
	190	return ret;
	191	}
	192
	193	static int set_tracing_cpu(struct perf_ftrace *ftrace)
	194	{
f854839b	195	struct perf_cpu_map *cpumap = ftrace->evlist->cpus;
dc231032 NK	196
	197	if (!target__has_cpu(&ftrace->target))
	198	return 0;
	199
	200	return set_tracing_cpumask(cpumap);
	201	}
	202
	203	static int reset_tracing_cpu(void)
	204	{
f854839b	205	struct perf_cpu_map *cpumap = cpu_map__new(NULL);
dc231032 NK	206	int ret;
	207
	208	ret = set_tracing_cpumask(cpumap);
	209	cpu_map__put(cpumap);
	210	return ret;
	211	}
	212
78b83e8b NK	213	static int __set_tracing_filter(const char filter_file, struct list_head funcs)
	214	{
	215	struct filter_entry *pos;
	216
	217	list_for_each_entry(pos, funcs, list) {
	218	if (append_tracing_file(filter_file, pos->name) < 0)
	219	return -1;
	220	}
	221
	222	return 0;
	223	}
	224
	225	static int set_tracing_filters(struct perf_ftrace *ftrace)
	226	{
	227	int ret;
	228
	229	ret = __set_tracing_filter("set_ftrace_filter", &ftrace->filters);
	230	if (ret < 0)
	231	return ret;
	232
	233	ret = __set_tracing_filter("set_ftrace_notrace", &ftrace->notrace);
	234	if (ret < 0)
	235	return ret;
	236
	237	ret = __set_tracing_filter("set_graph_function", &ftrace->graph_funcs);
	238	if (ret < 0)
	239	return ret;
	240
	241	/* old kernels do not have this filter */
	242	__set_tracing_filter("set_graph_notrace", &ftrace->nograph_funcs);
	243
	244	return ret;
	245	}
	246
	247	static void reset_tracing_filters(void)
	248	{
	249	write_tracing_file("set_ftrace_filter", " ");
	250	write_tracing_file("set_ftrace_notrace", " ");
	251	write_tracing_file("set_graph_function", " ");
	252	write_tracing_file("set_graph_notrace", " ");
	253	}
	254
1096c35a NK	255	static int set_tracing_depth(struct perf_ftrace *ftrace)
	256	{
	257	char buf[16];
	258
	259	if (ftrace->graph_depth == 0)
	260	return 0;
	261
	262	if (ftrace->graph_depth < 0) {
	263	pr_err("invalid graph depth: %d\n", ftrace->graph_depth);
	264	return -1;
	265	}
	266
	267	snprintf(buf, sizeof(buf), "%d", ftrace->graph_depth);
	268
	269	if (write_tracing_file("max_graph_depth", buf) < 0)
	270	return -1;
	271
	272	return 0;
	273	}
	274
d01f4e8d NK	275	static int __cmd_ftrace(struct perf_ftrace ftrace, int argc, const char *argv)
	276	{
	277	char *trace_file;
	278	int trace_fd;
d01f4e8d NK	279	char buf[4096];
	280	struct pollfd pollfd = {
	281	.events = POLLIN,
	282	};
	283
	284	if (geteuid() != 0) {
	285	pr_err("ftrace only works for root!\n");
	286	return -1;
	287	}
	288
d01f4e8d NK	289	signal(SIGINT, sig_handler);
	290	signal(SIGUSR1, sig_handler);
	291	signal(SIGCHLD, sig_handler);
58335964	292	signal(SIGPIPE, sig_handler);
d01f4e8d	293
63cd02d8 CD	294	if (reset_tracing_files(ftrace) < 0) {
63cd02d8 CD	295	pr_err("failed to reset ftrace\n");
a9af6be5	296	goto out;
63cd02d8	297	}
d01f4e8d NK	298
	299	/* reset ftrace buffer */
	300	if (write_tracing_file("trace", "0") < 0)
	301	goto out;
	302
a9af6be5 NK	303	if (argc && perf_evlist__prepare_workload(ftrace->evlist,
	304	&ftrace->target, argv, false,
	305	ftrace__workload_exec_failed_signal) < 0) {
d01f4e8d NK	306	goto out;
	307	}
	308
a9af6be5 NK	309	if (set_tracing_pid(ftrace) < 0) {
	310	pr_err("failed to set ftrace pid\n");
	311	goto out_reset;
d01f4e8d NK	312	}
d01f4e8d NK	313
dc231032 NK	314	if (set_tracing_cpu(ftrace) < 0) {
	315	pr_err("failed to set tracing cpumask\n");
	316	goto out_reset;
	317	}
	318
78b83e8b NK	319	if (set_tracing_filters(ftrace) < 0) {
	320	pr_err("failed to set tracing filters\n");
	321	goto out_reset;
	322	}
	323
1096c35a NK	324	if (set_tracing_depth(ftrace) < 0) {
	325	pr_err("failed to set graph depth\n");
	326	goto out_reset;
	327	}
	328
a9af6be5 NK	329	if (write_tracing_file("current_tracer", ftrace->tracer) < 0) {
	330	pr_err("failed to set current_tracer to %s\n", ftrace->tracer);
	331	goto out_reset;
d01f4e8d NK	332	}
d01f4e8d NK	333
29681bc5 NK	334	setup_pager();
29681bc5 NK	335
d01f4e8d NK	336	trace_file = get_tracing_file("trace_pipe");
	337	if (!trace_file) {
	338	pr_err("failed to open trace_pipe\n");
a9af6be5	339	goto out_reset;
d01f4e8d NK	340	}
	341
	342	trace_fd = open(trace_file, O_RDONLY);
	343
	344	put_tracing_file(trace_file);
	345
	346	if (trace_fd < 0) {
	347	pr_err("failed to open trace_pipe\n");
a9af6be5	348	goto out_reset;
d01f4e8d NK	349	}
	350
	351	fcntl(trace_fd, F_SETFL, O_NONBLOCK);
	352	pollfd.fd = trace_fd;
	353
	354	if (write_tracing_file("tracing_on", "1") < 0) {
	355	pr_err("can't enable tracing\n");
	356	goto out_close_fd;
	357	}
	358
	359	perf_evlist__start_workload(ftrace->evlist);
	360
	361	while (!done) {
	362	if (poll(&pollfd, 1, -1) < 0)
	363	break;
	364
	365	if (pollfd.revents & POLLIN) {
	366	int n = read(trace_fd, buf, sizeof(buf));
	367	if (n < 0)
	368	break;
	369	if (fwrite(buf, n, 1, stdout) != 1)
	370	break;
	371	}
	372	}
	373
	374	write_tracing_file("tracing_on", "0");
	375
	376	/* read remaining buffer contents */
	377	while (true) {
	378	int n = read(trace_fd, buf, sizeof(buf));
	379	if (n <= 0)
	380	break;
	381	if (fwrite(buf, n, 1, stdout) != 1)
	382	break;
	383	}
	384
	385	out_close_fd:
	386	close(trace_fd);
a9af6be5	387	out_reset:
d01f4e8d	388	reset_tracing_files(ftrace);
a9af6be5	389	out:
d01f4e8d NK	390	return done ? 0 : -1;
	391	}
	392
b05d1093 TS	393	static int perf_ftrace_config(const char var, const char value, void *cb)
	394	{
	395	struct perf_ftrace *ftrace = cb;
	396
8e99b6d4	397	if (!strstarts(var, "ftrace."))
b05d1093 TS	398	return 0;
	399
	400	if (strcmp(var, "ftrace.tracer"))
	401	return -1;
	402
	403	if (!strcmp(value, "function_graph") \|\|
	404	!strcmp(value, "function")) {
	405	ftrace->tracer = value;
	406	return 0;
	407	}
	408
	409	pr_err("Please select \"function_graph\" (default) or \"function\"\n");
	410	return -1;
	411	}
	412
78b83e8b NK	413	static int parse_filter_func(const struct option opt, const char str,
	414	int unset __maybe_unused)
	415	{
	416	struct list_head *head = opt->value;
	417	struct filter_entry *entry;
	418
	419	entry = malloc(sizeof(*entry) + strlen(str) + 1);
	420	if (entry == NULL)
	421	return -ENOMEM;
	422
	423	strcpy(entry->name, str);
	424	list_add_tail(&entry->list, head);
	425
	426	return 0;
	427	}
	428
	429	static void delete_filter_func(struct list_head *head)
	430	{
	431	struct filter_entry pos, tmp;
	432
	433	list_for_each_entry_safe(pos, tmp, head, list) {
e56fbc9d	434	list_del_init(&pos->list);
78b83e8b NK	435	free(pos);
	436	}
	437	}
	438
b0ad8ea6	439	int cmd_ftrace(int argc, const char **argv)
d01f4e8d NK	440	{
	441	int ret;
	442	struct perf_ftrace ftrace = {
bf062bd2	443	.tracer = DEFAULT_TRACER,
d01f4e8d NK	444	.target = { .uid = UINT_MAX, },
	445	};
	446	const char * const ftrace_usage[] = {
a9af6be5	447	"perf ftrace [<options>] [<command>]",
d01f4e8d NK	448	"perf ftrace [<options>] -- <command> [<options>]",
	449	NULL
	450	};
	451	const struct option ftrace_options[] = {
	452	OPT_STRING('t', "tracer", &ftrace.tracer, "tracer",
ec347870	453	"tracer to use: function_graph(default) or function"),
a9af6be5 NK	454	OPT_STRING('p', "pid", &ftrace.target.pid, "pid",
a9af6be5 NK	455	"trace on existing process id"),
d01f4e8d NK	456	OPT_INCR('v', "verbose", &verbose,
d01f4e8d NK	457	"be more verbose"),
dc231032 NK	458	OPT_BOOLEAN('a', "all-cpus", &ftrace.target.system_wide,
	459	"system-wide collection from all CPUs"),
	460	OPT_STRING('C', "cpu", &ftrace.target.cpu_list, "cpu",
	461	"list of cpus to monitor"),
78b83e8b NK	462	OPT_CALLBACK('T', "trace-funcs", &ftrace.filters, "func",
	463	"trace given functions only", parse_filter_func),
	464	OPT_CALLBACK('N', "notrace-funcs", &ftrace.notrace, "func",
	465	"do not trace given functions", parse_filter_func),
	466	OPT_CALLBACK('G', "graph-funcs", &ftrace.graph_funcs, "func",
	467	"Set graph filter on given functions", parse_filter_func),
	468	OPT_CALLBACK('g', "nograph-funcs", &ftrace.nograph_funcs, "func",
	469	"Set nograph filter on given functions", parse_filter_func),
1096c35a NK	470	OPT_INTEGER('D', "graph-depth", &ftrace.graph_depth,
1096c35a NK	471	"Max depth for function graph tracer"),
d01f4e8d NK	472	OPT_END()
	473	};
	474
78b83e8b NK	475	INIT_LIST_HEAD(&ftrace.filters);
	476	INIT_LIST_HEAD(&ftrace.notrace);
	477	INIT_LIST_HEAD(&ftrace.graph_funcs);
	478	INIT_LIST_HEAD(&ftrace.nograph_funcs);
	479
b05d1093 TS	480	ret = perf_config(perf_ftrace_config, &ftrace);
	481	if (ret < 0)
	482	return -1;
	483
d01f4e8d NK	484	argc = parse_options(argc, argv, ftrace_options, ftrace_usage,
d01f4e8d NK	485	PARSE_OPT_STOP_AT_NON_OPTION);
a9af6be5	486	if (!argc && target__none(&ftrace.target))
d01f4e8d NK	487	usage_with_options(ftrace_usage, ftrace_options);
d01f4e8d NK	488
a9af6be5 NK	489	ret = target__validate(&ftrace.target);
	490	if (ret) {
	491	char errbuf[512];
	492
	493	target__strerror(&ftrace.target, ret, errbuf, 512);
	494	pr_err("%s\n", errbuf);
78b83e8b	495	goto out_delete_filters;
a9af6be5 NK	496	}
a9af6be5 NK	497
d01f4e8d	498	ftrace.evlist = perf_evlist__new();
78b83e8b NK	499	if (ftrace.evlist == NULL) {
	500	ret = -ENOMEM;
	501	goto out_delete_filters;
	502	}
d01f4e8d NK	503
	504	ret = perf_evlist__create_maps(ftrace.evlist, &ftrace.target);
	505	if (ret < 0)
	506	goto out_delete_evlist;
	507
d01f4e8d NK	508	ret = __cmd_ftrace(&ftrace, argc, argv);
	509
	510	out_delete_evlist:
	511	perf_evlist__delete(ftrace.evlist);
	512
78b83e8b NK	513	out_delete_filters:
	514	delete_filter_func(&ftrace.filters);
	515	delete_filter_func(&ftrace.notrace);
	516	delete_filter_func(&ftrace.graph_funcs);
	517	delete_filter_func(&ftrace.nograph_funcs);
	518
d01f4e8d NK	519	return ret;
d01f4e8d NK	520	}