[mirror_ubuntu-hirsute-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 "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;
};

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;

	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\n", name);
		goto out;
	}

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

	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 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;

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

	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;
	}

	setup_pager();

	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 (prefixcmp(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;
}

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_END()
	};

	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);
		return -EINVAL;
	}

	ftrace.evlist = perf_evlist__new();
	if (ftrace.evlist == NULL)
		return -ENOMEM;

	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);

	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>
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 {
	30	struct perf_evlist *evlist;
	31	struct target target;
	32	const char *tracer;
	33	};
	34
	35	static bool done;
	36
	37	static void sig_handler(int sig __maybe_unused)
	38	{
	39	done = true;
	40	}
	41
	42	/*
	43	* perf_evlist__prepare_workload will send a SIGUSR1 if the fork fails, since
	44	* we asked by setting its exec_error to the function below,
	45	* ftrace__workload_exec_failed_signal.
	46	*
	47	* XXX We need to handle this more appropriately, emitting an error, etc.
	48	*/
	49	static void ftrace__workload_exec_failed_signal(int signo __maybe_unused,
	50	siginfo_t *info __maybe_unused,
	51	void *ucontext __maybe_unused)
	52	{
	53	/* workload_exec_errno = info->si_value.sival_int; */
	54	done = true;
	55	}
	56
a9af6be5	57	static int __write_tracing_file(const char name, const char val, bool append)
d01f4e8d NK	58	{
	59	char *file;
	60	int fd, ret = -1;
	61	ssize_t size = strlen(val);
a9af6be5	62	int flags = O_WRONLY;
d01f4e8d NK	63
	64	file = get_tracing_file(name);
	65	if (!file) {
	66	pr_debug("cannot get tracing file: %s\n", name);
	67	return -1;
	68	}
	69
a9af6be5 NK	70	if (append)
	71	flags \|= O_APPEND;
	72	else
	73	flags \|= O_TRUNC;
	74
	75	fd = open(file, flags);
d01f4e8d NK	76	if (fd < 0) {
	77	pr_debug("cannot open tracing file: %s\n", name);
	78	goto out;
	79	}
	80
	81	if (write(fd, val, size) == size)
	82	ret = 0;
	83	else
	84	pr_debug("write '%s' to tracing/%s failed\n", val, name);
	85
	86	close(fd);
	87	out:
	88	put_tracing_file(file);
	89	return ret;
	90	}
	91
a9af6be5 NK	92	static int write_tracing_file(const char name, const char val)
	93	{
	94	return __write_tracing_file(name, val, false);
	95	}
	96
	97	static int append_tracing_file(const char name, const char val)
	98	{
	99	return __write_tracing_file(name, val, true);
	100	}
	101
dc231032 NK	102	static int reset_tracing_cpu(void);
dc231032 NK	103
d01f4e8d NK	104	static int reset_tracing_files(struct perf_ftrace *ftrace __maybe_unused)
	105	{
	106	if (write_tracing_file("tracing_on", "0") < 0)
	107	return -1;
	108
	109	if (write_tracing_file("current_tracer", "nop") < 0)
	110	return -1;
	111
	112	if (write_tracing_file("set_ftrace_pid", " ") < 0)
	113	return -1;
	114
dc231032 NK	115	if (reset_tracing_cpu() < 0)
	116	return -1;
	117
d01f4e8d NK	118	return 0;
	119	}
	120
a9af6be5 NK	121	static int set_tracing_pid(struct perf_ftrace *ftrace)
	122	{
	123	int i;
	124	char buf[16];
	125
	126	if (target__has_cpu(&ftrace->target))
	127	return 0;
	128
	129	for (i = 0; i < thread_map__nr(ftrace->evlist->threads); i++) {
	130	scnprintf(buf, sizeof(buf), "%d",
	131	ftrace->evlist->threads->map[i]);
	132	if (append_tracing_file("set_ftrace_pid", buf) < 0)
	133	return -1;
	134	}
	135	return 0;
	136	}
	137
dc231032 NK	138	static int set_tracing_cpumask(struct cpu_map *cpumap)
	139	{
	140	char *cpumask;
	141	size_t mask_size;
	142	int ret;
	143	int last_cpu;
	144
	145	last_cpu = cpu_map__cpu(cpumap, cpumap->nr - 1);
	146	mask_size = (last_cpu + 3) / 4 + 1;
	147	mask_size += last_cpu / 32; /* ',' is needed for every 32th cpus */
	148
	149	cpumask = malloc(mask_size);
	150	if (cpumask == NULL) {
	151	pr_debug("failed to allocate cpu mask\n");
	152	return -1;
	153	}
	154
	155	cpu_map__snprint_mask(cpumap, cpumask, mask_size);
	156
	157	ret = write_tracing_file("tracing_cpumask", cpumask);
	158
	159	free(cpumask);
	160	return ret;
	161	}
	162
	163	static int set_tracing_cpu(struct perf_ftrace *ftrace)
	164	{
	165	struct cpu_map *cpumap = ftrace->evlist->cpus;
	166
	167	if (!target__has_cpu(&ftrace->target))
	168	return 0;
	169
	170	return set_tracing_cpumask(cpumap);
	171	}
	172
	173	static int reset_tracing_cpu(void)
	174	{
	175	struct cpu_map *cpumap = cpu_map__new(NULL);
	176	int ret;
	177
	178	ret = set_tracing_cpumask(cpumap);
	179	cpu_map__put(cpumap);
	180	return ret;
	181	}
	182
d01f4e8d NK	183	static int __cmd_ftrace(struct perf_ftrace ftrace, int argc, const char *argv)
	184	{
	185	char *trace_file;
	186	int trace_fd;
d01f4e8d NK	187	char buf[4096];
	188	struct pollfd pollfd = {
	189	.events = POLLIN,
	190	};
	191
	192	if (geteuid() != 0) {
	193	pr_err("ftrace only works for root!\n");
	194	return -1;
	195	}
	196
d01f4e8d NK	197	signal(SIGINT, sig_handler);
	198	signal(SIGUSR1, sig_handler);
	199	signal(SIGCHLD, sig_handler);
58335964	200	signal(SIGPIPE, sig_handler);
d01f4e8d	201
a9af6be5 NK	202	if (reset_tracing_files(ftrace) < 0)
a9af6be5 NK	203	goto out;
d01f4e8d NK	204
	205	/* reset ftrace buffer */
	206	if (write_tracing_file("trace", "0") < 0)
	207	goto out;
	208
a9af6be5 NK	209	if (argc && perf_evlist__prepare_workload(ftrace->evlist,
	210	&ftrace->target, argv, false,
	211	ftrace__workload_exec_failed_signal) < 0) {
d01f4e8d NK	212	goto out;
	213	}
	214
a9af6be5 NK	215	if (set_tracing_pid(ftrace) < 0) {
	216	pr_err("failed to set ftrace pid\n");
	217	goto out_reset;
d01f4e8d NK	218	}
d01f4e8d NK	219
dc231032 NK	220	if (set_tracing_cpu(ftrace) < 0) {
	221	pr_err("failed to set tracing cpumask\n");
	222	goto out_reset;
	223	}
	224
a9af6be5 NK	225	if (write_tracing_file("current_tracer", ftrace->tracer) < 0) {
	226	pr_err("failed to set current_tracer to %s\n", ftrace->tracer);
	227	goto out_reset;
d01f4e8d NK	228	}
	229
	230	trace_file = get_tracing_file("trace_pipe");
	231	if (!trace_file) {
	232	pr_err("failed to open trace_pipe\n");
a9af6be5	233	goto out_reset;
d01f4e8d NK	234	}
	235
	236	trace_fd = open(trace_file, O_RDONLY);
	237
	238	put_tracing_file(trace_file);
	239
	240	if (trace_fd < 0) {
	241	pr_err("failed to open trace_pipe\n");
a9af6be5	242	goto out_reset;
d01f4e8d NK	243	}
	244
	245	fcntl(trace_fd, F_SETFL, O_NONBLOCK);
	246	pollfd.fd = trace_fd;
	247
	248	if (write_tracing_file("tracing_on", "1") < 0) {
	249	pr_err("can't enable tracing\n");
	250	goto out_close_fd;
	251	}
	252
58335964 NK	253	setup_pager();
58335964 NK	254
d01f4e8d NK	255	perf_evlist__start_workload(ftrace->evlist);
	256
	257	while (!done) {
	258	if (poll(&pollfd, 1, -1) < 0)
	259	break;
	260
	261	if (pollfd.revents & POLLIN) {
	262	int n = read(trace_fd, buf, sizeof(buf));
	263	if (n < 0)
	264	break;
	265	if (fwrite(buf, n, 1, stdout) != 1)
	266	break;
	267	}
	268	}
	269
	270	write_tracing_file("tracing_on", "0");
	271
	272	/* read remaining buffer contents */
	273	while (true) {
	274	int n = read(trace_fd, buf, sizeof(buf));
	275	if (n <= 0)
	276	break;
	277	if (fwrite(buf, n, 1, stdout) != 1)
	278	break;
	279	}
	280
	281	out_close_fd:
	282	close(trace_fd);
a9af6be5	283	out_reset:
d01f4e8d	284	reset_tracing_files(ftrace);
a9af6be5	285	out:
d01f4e8d NK	286	return done ? 0 : -1;
	287	}
	288
b05d1093 TS	289	static int perf_ftrace_config(const char var, const char value, void *cb)
	290	{
	291	struct perf_ftrace *ftrace = cb;
	292
	293	if (prefixcmp(var, "ftrace."))
	294	return 0;
	295
	296	if (strcmp(var, "ftrace.tracer"))
	297	return -1;
	298
	299	if (!strcmp(value, "function_graph") \|\|
	300	!strcmp(value, "function")) {
	301	ftrace->tracer = value;
	302	return 0;
	303	}
	304
	305	pr_err("Please select \"function_graph\" (default) or \"function\"\n");
	306	return -1;
	307	}
	308
b0ad8ea6	309	int cmd_ftrace(int argc, const char **argv)
d01f4e8d NK	310	{
	311	int ret;
	312	struct perf_ftrace ftrace = {
bf062bd2	313	.tracer = DEFAULT_TRACER,
d01f4e8d NK	314	.target = { .uid = UINT_MAX, },
	315	};
	316	const char * const ftrace_usage[] = {
a9af6be5	317	"perf ftrace [<options>] [<command>]",
d01f4e8d NK	318	"perf ftrace [<options>] -- <command> [<options>]",
	319	NULL
	320	};
	321	const struct option ftrace_options[] = {
	322	OPT_STRING('t', "tracer", &ftrace.tracer, "tracer",
ec347870	323	"tracer to use: function_graph(default) or function"),
a9af6be5 NK	324	OPT_STRING('p', "pid", &ftrace.target.pid, "pid",
a9af6be5 NK	325	"trace on existing process id"),
d01f4e8d NK	326	OPT_INCR('v', "verbose", &verbose,
d01f4e8d NK	327	"be more verbose"),
dc231032 NK	328	OPT_BOOLEAN('a', "all-cpus", &ftrace.target.system_wide,
	329	"system-wide collection from all CPUs"),
	330	OPT_STRING('C', "cpu", &ftrace.target.cpu_list, "cpu",
	331	"list of cpus to monitor"),
d01f4e8d NK	332	OPT_END()
	333	};
	334
b05d1093 TS	335	ret = perf_config(perf_ftrace_config, &ftrace);
	336	if (ret < 0)
	337	return -1;
	338
d01f4e8d NK	339	argc = parse_options(argc, argv, ftrace_options, ftrace_usage,
d01f4e8d NK	340	PARSE_OPT_STOP_AT_NON_OPTION);
a9af6be5	341	if (!argc && target__none(&ftrace.target))
d01f4e8d NK	342	usage_with_options(ftrace_usage, ftrace_options);
d01f4e8d NK	343
a9af6be5 NK	344	ret = target__validate(&ftrace.target);
	345	if (ret) {
	346	char errbuf[512];
	347
	348	target__strerror(&ftrace.target, ret, errbuf, 512);
	349	pr_err("%s\n", errbuf);
	350	return -EINVAL;
	351	}
	352
d01f4e8d NK	353	ftrace.evlist = perf_evlist__new();
	354	if (ftrace.evlist == NULL)
	355	return -ENOMEM;
	356
	357	ret = perf_evlist__create_maps(ftrace.evlist, &ftrace.target);
	358	if (ret < 0)
	359	goto out_delete_evlist;
	360
d01f4e8d NK	361	ret = __cmd_ftrace(&ftrace, argc, argv);
	362
	363	out_delete_evlist:
	364	perf_evlist__delete(ftrace.evlist);
	365
	366	return ret;
	367	}