[mirror_ubuntu-bionic-kernel.git] / tools / perf / builtin-probe.c

/*
 * builtin-probe.c
 *
 * Builtin probe command: Set up probe events by C expression
 *
 * Written by Masami Hiramatsu <mhiramat@redhat.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 *
 */
#define _GNU_SOURCE
#include <sys/utsname.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <errno.h>
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>

#undef _GNU_SOURCE
#include "perf.h"
#include "builtin.h"
#include "util/util.h"
#include "util/strlist.h"
#include "util/event.h"
#include "util/debug.h"
#include "util/symbol.h"
#include "util/thread.h"
#include "util/session.h"
#include "util/parse-options.h"
#include "util/parse-events.h"	/* For debugfs_path */
#include "util/probe-finder.h"
#include "util/probe-event.h"

#define MAX_PATH_LEN 256
#define MAX_PROBES 128

/* Session management structure */
static struct {
	bool need_dwarf;
	bool list_events;
	bool force_add;
	int nr_probe;
	struct probe_point probes[MAX_PROBES];
	struct strlist *dellist;
	struct perf_session *psession;
	struct map *kmap;
} session;


/* Parse an event definition. Note that any error must die. */
static void parse_probe_event(const char *str)
{
	struct probe_point *pp = &session.probes[session.nr_probe];

	pr_debug("probe-definition(%d): %s\n", session.nr_probe, str);
	if (++session.nr_probe == MAX_PROBES)
		die("Too many probes (> %d) are specified.", MAX_PROBES);

	/* Parse perf-probe event into probe_point */
	parse_perf_probe_event(str, pp, &session.need_dwarf);

	pr_debug("%d arguments\n", pp->nr_args);
}

static void parse_probe_event_argv(int argc, const char **argv)
{
	int i, len;
	char *buf;

	/* Bind up rest arguments */
	len = 0;
	for (i = 0; i < argc; i++)
		len += strlen(argv[i]) + 1;
	buf = zalloc(len + 1);
	if (!buf)
		die("Failed to allocate memory for binding arguments.");
	len = 0;
	for (i = 0; i < argc; i++)
		len += sprintf(&buf[len], "%s ", argv[i]);
	parse_probe_event(buf);
	free(buf);
}

static int opt_add_probe_event(const struct option *opt __used,
			      const char *str, int unset __used)
{
	if (str)
		parse_probe_event(str);
	return 0;
}

static int opt_del_probe_event(const struct option *opt __used,
			       const char *str, int unset __used)
{
	if (str) {
		if (!session.dellist)
			session.dellist = strlist__new(true, NULL);
		strlist__add(session.dellist, str);
	}
	return 0;
}

/* Currently just checking function name from symbol map */
static void evaluate_probe_point(struct probe_point *pp)
{
	struct symbol *sym;
	sym = map__find_symbol_by_name(session.kmap, pp->function,
				       session.psession, NULL);
	if (!sym)
		die("Kernel symbol \'%s\' not found - probe not added.",
		    pp->function);
}

#ifndef NO_LIBDWARF
static int open_vmlinux(void)
{
	if (map__load(session.kmap, session.psession, NULL) < 0) {
		pr_debug("Failed to load kernel map.\n");
		return -EINVAL;
	}
	pr_debug("Try to open %s\n", session.kmap->dso->long_name);
	return open(session.kmap->dso->long_name, O_RDONLY);
}
#endif

static const char * const probe_usage[] = {
	"perf probe [<options>] 'PROBEDEF' ['PROBEDEF' ...]",
	"perf probe [<options>] --add 'PROBEDEF' [--add 'PROBEDEF' ...]",
	"perf probe [<options>] --del '[GROUP:]EVENT' ...",
	"perf probe --list",
	NULL
};

static const struct option options[] = {
	OPT_BOOLEAN('v', "verbose", &verbose,
		    "be more verbose (show parsed arguments, etc)"),
#ifndef NO_LIBDWARF
	OPT_STRING('k', "vmlinux", &symbol_conf.vmlinux_name,
		   "file", "vmlinux pathname"),
#endif
	OPT_BOOLEAN('l', "list", &session.list_events,
		    "list up current probe events"),
	OPT_CALLBACK('d', "del", NULL, "[GROUP:]EVENT", "delete a probe event.",
		opt_del_probe_event),
	OPT_CALLBACK('a', "add", NULL,
#ifdef NO_LIBDWARF
		"[EVENT=]FUNC[+OFFS|%return] [ARG ...]",
#else
		"[EVENT=]FUNC[+OFFS|%return|:RLN][@SRC]|SRC:ALN [ARG ...]",
#endif
		"probe point definition, where\n"
		"\t\tGROUP:\tGroup name (optional)\n"
		"\t\tEVENT:\tEvent name\n"
		"\t\tFUNC:\tFunction name\n"
		"\t\tOFFS:\tOffset from function entry (in byte)\n"
		"\t\t%return:\tPut the probe at function return\n"
#ifdef NO_LIBDWARF
		"\t\tARG:\tProbe argument (only \n"
#else
		"\t\tSRC:\tSource code path\n"
		"\t\tRLN:\tRelative line number from function entry.\n"
		"\t\tALN:\tAbsolute line number in file.\n"
		"\t\tARG:\tProbe argument (local variable name or\n"
#endif
		"\t\t\tkprobe-tracer argument format.)\n",
		opt_add_probe_event),
	OPT_BOOLEAN('f', "force", &session.force_add, "forcibly add events"
		    " with existing name"),
	OPT_END()
};

int cmd_probe(int argc, const char **argv, const char *prefix __used)
{
	int i, ret;
#ifndef NO_LIBDWARF
	int fd;
#endif
	struct probe_point *pp;

	argc = parse_options(argc, argv, options, probe_usage,
			     PARSE_OPT_STOP_AT_NON_OPTION);
	if (argc > 0) {
		if (strcmp(argv[0], "-") == 0) {
			pr_warning("  Error: '-' is not supported.\n");
			usage_with_options(probe_usage, options);
		}
		parse_probe_event_argv(argc, argv);
	}

	if ((!session.nr_probe && !session.dellist && !session.list_events))
		usage_with_options(probe_usage, options);

	if (session.list_events) {
		if (session.nr_probe != 0 || session.dellist) {
			pr_warning("  Error: Don't use --list with"
				   " --add/--del.\n");
			usage_with_options(probe_usage, options);
		}
		show_perf_probe_events();
		return 0;
	}

	if (session.dellist) {
		del_trace_kprobe_events(session.dellist);
		strlist__delete(session.dellist);
		if (session.nr_probe == 0)
			return 0;
	}

	/* Initialize symbol maps for vmlinux */
	symbol_conf.sort_by_name = true;
	if (symbol_conf.vmlinux_name == NULL)
		symbol_conf.try_vmlinux_path = true;
	if (symbol__init() < 0)
		die("Failed to init symbol map.");
	session.psession = perf_session__new(NULL, O_WRONLY, false);
	if (session.psession == NULL)
		die("Failed to init perf_session.");
	session.kmap = map_groups__find_by_name(&session.psession->kmaps,
						MAP__FUNCTION,
						"[kernel.kallsyms]");
	if (!session.kmap)
		die("Could not find kernel map.\n");

	if (session.need_dwarf)
#ifdef NO_LIBDWARF
		die("Debuginfo-analysis is not supported");
#else	/* !NO_LIBDWARF */
		pr_debug("Some probes require debuginfo.\n");

	fd = open_vmlinux();
	if (fd < 0) {
		if (session.need_dwarf)
			die("Could not open debuginfo file.");

		pr_debug("Could not open vmlinux/module file."
			 " Try to use symbols.\n");
		goto end_dwarf;
	}

	/* Searching probe points */
	for (i = 0; i < session.nr_probe; i++) {
		pp = &session.probes[i];
		if (pp->found)
			continue;

		lseek(fd, SEEK_SET, 0);
		ret = find_probepoint(fd, pp);
		if (ret > 0)
			continue;
		if (ret == 0) {	/* No error but failed to find probe point. */
			synthesize_perf_probe_point(pp);
			die("Probe point '%s' not found. - probe not added.",
			    pp->probes[0]);
		}
		/* Error path */
		if (session.need_dwarf) {
			if (ret == -ENOENT)
				pr_warning("No dwarf info found in the vmlinux - please rebuild with CONFIG_DEBUG_INFO=y.\n");
			die("Could not analyze debuginfo.");
		}
		pr_debug("An error occurred in debuginfo analysis."
			 " Try to use symbols.\n");
		break;
	}
	close(fd);

end_dwarf:
#endif /* !NO_LIBDWARF */

	/* Synthesize probes without dwarf */
	for (i = 0; i < session.nr_probe; i++) {
		pp = &session.probes[i];
		if (pp->found)	/* This probe is already found. */
			continue;

		evaluate_probe_point(pp);
		ret = synthesize_trace_kprobe_event(pp);
		if (ret == -E2BIG)
			die("probe point definition becomes too long.");
		else if (ret < 0)
			die("Failed to synthesize a probe point.");
	}

	/* Settng up probe points */
	add_trace_kprobe_events(session.probes, session.nr_probe,
				session.force_add);
	return 0;
}
Commit	Line	Data
4ea42b18 MH	1	/*
	2	* builtin-probe.c
	3	*
	4	* Builtin probe command: Set up probe events by C expression
	5	*
	6	* Written by Masami Hiramatsu <mhiramat@redhat.com>
	7	*
	8	* This program is free software; you can redistribute it and/or modify
	9	* it under the terms of the GNU General Public License as published by
	10	* the Free Software Foundation; either version 2 of the License, or
	11	* (at your option) any later version.
	12	*
	13	* This program is distributed in the hope that it will be useful,
	14	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	15	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	16	* GNU General Public License for more details.
	17	*
	18	* You should have received a copy of the GNU General Public License
	19	* along with this program; if not, write to the Free Software
	20	* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
	21	*
	22	*/
	23	#define _GNU_SOURCE
	24	#include <sys/utsname.h>
	25	#include <sys/types.h>
	26	#include <sys/stat.h>
	27	#include <fcntl.h>
	28	#include <errno.h>
	29	#include <stdio.h>
	30	#include <unistd.h>
	31	#include <stdlib.h>
	32	#include <string.h>
	33
	34	#undef _GNU_SOURCE
	35	#include "perf.h"
	36	#include "builtin.h"
	37	#include "util/util.h"
fa28244d	38	#include "util/strlist.h"
89c69c0e MH	39	#include "util/event.h"
89c69c0e MH	40	#include "util/debug.h"
a128168d MH	41	#include "util/symbol.h"
	42	#include "util/thread.h"
	43	#include "util/session.h"
4ea42b18 MH	44	#include "util/parse-options.h"
	45	#include "util/parse-events.h" /* For debugfs_path */
	46	#include "util/probe-finder.h"
50656eec	47	#include "util/probe-event.h"
4ea42b18	48
4ea42b18 MH	49	#define MAX_PATH_LEN 256
	50	#define MAX_PROBES 128
	51
	52	/* Session management structure */
	53	static struct {
fac13fd5 MH	54	bool need_dwarf;
fac13fd5 MH	55	bool list_events;
d761b08b	56	bool force_add;
4ea42b18 MH	57	int nr_probe;
4ea42b18 MH	58	struct probe_point probes[MAX_PROBES];
fa28244d	59	struct strlist *dellist;
a128168d	60	struct perf_session *psession;
62bdc1b3	61	struct map *kmap;
4ea42b18 MH	62	} session;
4ea42b18 MH	63
4de189fe	64
253977b0 MH	65	/* Parse an event definition. Note that any error must die. */
253977b0 MH	66	static void parse_probe_event(const char *str)
4ea42b18	67	{
4ea42b18	68	struct probe_point *pp = &session.probes[session.nr_probe];
4ea42b18	69
b7cb10e7	70	pr_debug("probe-definition(%d): %s\n", session.nr_probe, str);
4ea42b18	71	if (++session.nr_probe == MAX_PROBES)
50656eec	72	die("Too many probes (> %d) are specified.", MAX_PROBES);
4ea42b18	73
50656eec	74	/* Parse perf-probe event into probe_point */
fac13fd5	75	parse_perf_probe_event(str, pp, &session.need_dwarf);
23e8ec0d	76
b7cb10e7	77	pr_debug("%d arguments\n", pp->nr_args);
46ab4926 MH	78	}
46ab4926 MH	79
d1bde3f7 MH	80	static void parse_probe_event_argv(int argc, const char **argv)
	81	{
	82	int i, len;
	83	char *buf;
	84
	85	/* Bind up rest arguments */
	86	len = 0;
	87	for (i = 0; i < argc; i++)
	88	len += strlen(argv[i]) + 1;
	89	buf = zalloc(len + 1);
	90	if (!buf)
	91	die("Failed to allocate memory for binding arguments.");
	92	len = 0;
	93	for (i = 0; i < argc; i++)
	94	len += sprintf(&buf[len], "%s ", argv[i]);
	95	parse_probe_event(buf);
	96	free(buf);
	97	}
	98
253977b0	99	static int opt_add_probe_event(const struct option *opt __used,
46ab4926 MH	100	const char *str, int unset __used)
	101	{
	102	if (str)
253977b0	103	parse_probe_event(str);
4ea42b18 MH	104	return 0;
	105	}
	106
fa28244d MH	107	static int opt_del_probe_event(const struct option *opt __used,
	108	const char *str, int unset __used)
	109	{
	110	if (str) {
	111	if (!session.dellist)
	112	session.dellist = strlist__new(true, NULL);
	113	strlist__add(session.dellist, str);
	114	}
	115	return 0;
	116	}
	117
62bdc1b3 MH	118	/* Currently just checking function name from symbol map */
	119	static void evaluate_probe_point(struct probe_point *pp)
	120	{
	121	struct symbol *sym;
	122	sym = map__find_symbol_by_name(session.kmap, pp->function,
	123	session.psession, NULL);
	124	if (!sym)
	125	die("Kernel symbol \'%s\' not found - probe not added.",
	126	pp->function);
	127	}
	128
23e8ec0d	129	#ifndef NO_LIBDWARF
a128168d	130	static int open_vmlinux(void)
4ea42b18	131	{
62bdc1b3	132	if (map__load(session.kmap, session.psession, NULL) < 0) {
a128168d MH	133	pr_debug("Failed to load kernel map.\n");
a128168d MH	134	return -EINVAL;
4ea42b18	135	}
62bdc1b3 MH	136	pr_debug("Try to open %s\n", session.kmap->dso->long_name);
62bdc1b3 MH	137	return open(session.kmap->dso->long_name, O_RDONLY);
4ea42b18	138	}
23e8ec0d	139	#endif
4ea42b18 MH	140
4ea42b18 MH	141	static const char * const probe_usage[] = {
46ab4926 MH	142	"perf probe [<options>] 'PROBEDEF' ['PROBEDEF' ...]",
46ab4926 MH	143	"perf probe [<options>] --add 'PROBEDEF' [--add 'PROBEDEF' ...]",
fa28244d	144	"perf probe [<options>] --del '[GROUP:]EVENT' ...",
4de189fe	145	"perf probe --list",
4ea42b18 MH	146	NULL
	147	};
	148
	149	static const struct option options[] = {
89c69c0e MH	150	OPT_BOOLEAN('v', "verbose", &verbose,
89c69c0e MH	151	"be more verbose (show parsed arguments, etc)"),
23e8ec0d	152	#ifndef NO_LIBDWARF
75be6cf4	153	OPT_STRING('k', "vmlinux", &symbol_conf.vmlinux_name,
a128168d	154	"file", "vmlinux pathname"),
23e8ec0d	155	#endif
fac13fd5 MH	156	OPT_BOOLEAN('l', "list", &session.list_events,
fac13fd5 MH	157	"list up current probe events"),
fa28244d MH	158	OPT_CALLBACK('d', "del", NULL, "[GROUP:]EVENT", "delete a probe event.",
fa28244d MH	159	opt_del_probe_event),
46ab4926	160	OPT_CALLBACK('a', "add", NULL,
23e8ec0d	161	#ifdef NO_LIBDWARF
af663d75	162	"[EVENT=]FUNC[+OFFS\|%return] [ARG ...]",
23e8ec0d	163	#else
af663d75	164	"[EVENT=]FUNC[+OFFS\|%return\|:RLN][@SRC]\|SRC:ALN [ARG ...]",
23e8ec0d	165	#endif
4ea42b18	166	"probe point definition, where\n"
af663d75 MH	167	"\t\tGROUP:\tGroup name (optional)\n"
af663d75 MH	168	"\t\tEVENT:\tEvent name\n"
4ea42b18 MH	169	"\t\tFUNC:\tFunction name\n"
4ea42b18 MH	170	"\t\tOFFS:\tOffset from function entry (in byte)\n"
253977b0	171	"\t\t%return:\tPut the probe at function return\n"
23e8ec0d MH	172	#ifdef NO_LIBDWARF
	173	"\t\tARG:\tProbe argument (only \n"
	174	#else
4ea42b18	175	"\t\tSRC:\tSource code path\n"
b0ef0732 MH	176	"\t\tRLN:\tRelative line number from function entry.\n"
b0ef0732 MH	177	"\t\tALN:\tAbsolute line number in file.\n"
4ea42b18	178	"\t\tARG:\tProbe argument (local variable name or\n"
23e8ec0d	179	#endif
50656eec	180	"\t\t\tkprobe-tracer argument format.)\n",
253977b0	181	opt_add_probe_event),
d761b08b MH	182	OPT_BOOLEAN('f', "force", &session.force_add, "forcibly add events"
d761b08b MH	183	" with existing name"),
4ea42b18 MH	184	OPT_END()
	185	};
	186
4ea42b18 MH	187	int cmd_probe(int argc, const char *argv, const char prefix __used)
4ea42b18 MH	188	{
d1bde3f7	189	int i, ret;
bdad0db7 XG	190	#ifndef NO_LIBDWARF
	191	int fd;
	192	#endif
4ea42b18	193	struct probe_point *pp;
4ea42b18 MH	194
4ea42b18 MH	195	argc = parse_options(argc, argv, options, probe_usage,
46ab4926	196	PARSE_OPT_STOP_AT_NON_OPTION);
ce11a603 MH	197	if (argc > 0) {
	198	if (strcmp(argv[0], "-") == 0) {
	199	pr_warning(" Error: '-' is not supported.\n");
	200	usage_with_options(probe_usage, options);
	201	}
d1bde3f7	202	parse_probe_event_argv(argc, argv);
ce11a603	203	}
46ab4926	204
fac13fd5	205	if ((!session.nr_probe && !session.dellist && !session.list_events))
4ea42b18 MH	206	usage_with_options(probe_usage, options);
4ea42b18 MH	207
fac13fd5	208	if (session.list_events) {
fa28244d MH	209	if (session.nr_probe != 0 \|\| session.dellist) {
	210	pr_warning(" Error: Don't use --list with"
	211	" --add/--del.\n");
	212	usage_with_options(probe_usage, options);
	213	}
4de189fe MH	214	show_perf_probe_events();
	215	return 0;
	216	}
	217
fa28244d MH	218	if (session.dellist) {
	219	del_trace_kprobe_events(session.dellist);
	220	strlist__delete(session.dellist);
	221	if (session.nr_probe == 0)
	222	return 0;
	223	}
	224
a128168d	225	/* Initialize symbol maps for vmlinux */
75be6cf4 ACM	226	symbol_conf.sort_by_name = true;
	227	if (symbol_conf.vmlinux_name == NULL)
	228	symbol_conf.try_vmlinux_path = true;
	229	if (symbol__init() < 0)
a128168d	230	die("Failed to init symbol map.");
75be6cf4	231	session.psession = perf_session__new(NULL, O_WRONLY, false);
a128168d MH	232	if (session.psession == NULL)
a128168d MH	233	die("Failed to init perf_session.");
62bdc1b3 MH	234	session.kmap = map_groups__find_by_name(&session.psession->kmaps,
	235	MAP__FUNCTION,
	236	"[kernel.kallsyms]");
	237	if (!session.kmap)
	238	die("Could not find kernel map.\n");
a128168d	239
23e8ec0d	240	if (session.need_dwarf)
a225a1d9	241	#ifdef NO_LIBDWARF
50656eec	242	die("Debuginfo-analysis is not supported");
a225a1d9	243	#else /* !NO_LIBDWARF */
f41b1e43	244	pr_debug("Some probes require debuginfo.\n");
4ea42b18	245
a128168d	246	fd = open_vmlinux();
a225a1d9 MH	247	if (fd < 0) {
a225a1d9 MH	248	if (session.need_dwarf)
f984f03d	249	die("Could not open debuginfo file.");
a225a1d9	250
d3a2dbf8 MH	251	pr_debug("Could not open vmlinux/module file."
d3a2dbf8 MH	252	" Try to use symbols.\n");
a225a1d9 MH	253	goto end_dwarf;
a225a1d9 MH	254	}
4ea42b18 MH	255
4ea42b18 MH	256	/* Searching probe points */
d1bde3f7 MH	257	for (i = 0; i < session.nr_probe; i++) {
d1bde3f7 MH	258	pp = &session.probes[i];
4ea42b18 MH	259	if (pp->found)
	260	continue;
	261
	262	lseek(fd, SEEK_SET, 0);
	263	ret = find_probepoint(fd, pp);
411edfe5 MH	264	if (ret > 0)
411edfe5 MH	265	continue;
7ef17aaf MH	266	if (ret == 0) { /* No error but failed to find probe point. */
	267	synthesize_perf_probe_point(pp);
	268	die("Probe point '%s' not found. - probe not added.",
	269	pp->probes[0]);
	270	}
411edfe5 MH	271	/* Error path */
	272	if (session.need_dwarf) {
	273	if (ret == -ENOENT)
	274	pr_warning("No dwarf info found in the vmlinux - please rebuild with CONFIG_DEBUG_INFO=y.\n");
	275	die("Could not analyze debuginfo.");
	276	}
	277	pr_debug("An error occurred in debuginfo analysis."
	278	" Try to use symbols.\n");
	279	break;
4ea42b18 MH	280	}
	281	close(fd);
	282
a225a1d9	283	end_dwarf:
23e8ec0d MH	284	#endif /* !NO_LIBDWARF */
23e8ec0d MH	285
a225a1d9	286	/* Synthesize probes without dwarf */
d1bde3f7 MH	287	for (i = 0; i < session.nr_probe; i++) {
d1bde3f7 MH	288	pp = &session.probes[i];
a225a1d9 MH	289	if (pp->found) /* This probe is already found. */
	290	continue;
	291
62bdc1b3	292	evaluate_probe_point(pp);
50656eec	293	ret = synthesize_trace_kprobe_event(pp);
a225a1d9	294	if (ret == -E2BIG)
50656eec	295	die("probe point definition becomes too long.");
a225a1d9 MH	296	else if (ret < 0)
	297	die("Failed to synthesize a probe point.");
	298	}
	299
4ea42b18	300	/* Settng up probe points */
d761b08b MH	301	add_trace_kprobe_events(session.probes, session.nr_probe,
d761b08b MH	302	session.force_add);
4ea42b18 MH	303	return 0;
	304	}
	305