[deliverable/linux.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/event.h"
#include "util/debug.h"
#include "util/parse-options.h"
#include "util/parse-events.h"	/* For debugfs_path */
#include "util/probe-finder.h"

/* Default vmlinux search paths */
#define NR_SEARCH_PATH 3
const char *default_search_path[NR_SEARCH_PATH] = {
"/lib/modules/%s/build/vmlinux",		/* Custom build kernel */
"/usr/lib/debug/lib/modules/%s/vmlinux",	/* Red Hat debuginfo */
"/boot/vmlinux-debug-%s",			/* Ubuntu */
};

#define MAX_PATH_LEN 256
#define MAX_PROBES 128
#define MAX_PROBE_ARGS 128
#define PERFPROBE_GROUP "probe"

/* Session management structure */
static struct {
	char *vmlinux;
	char *release;
	int need_dwarf;
	int nr_probe;
	struct probe_point probes[MAX_PROBES];
} session;

#define semantic_error(msg ...) die("Semantic error :" msg)

/* Parse probe point. Return 1 if return probe */
static void parse_probe_point(char *arg, struct probe_point *pp)
{
	char *ptr, *tmp;
	char c, nc = 0;
	/*
	 * <Syntax>
	 * perf probe SRC:LN
	 * perf probe FUNC[+OFFS|%return][@SRC]
	 */

	ptr = strpbrk(arg, ":+@%");
	if (ptr) {
		nc = *ptr;
		*ptr++ = '\0';
	}

	/* Check arg is function or file and copy it */
	if (strchr(arg, '.'))	/* File */
		pp->file = strdup(arg);
	else			/* Function */
		pp->function = strdup(arg);
	DIE_IF(pp->file == NULL && pp->function == NULL);

	/* Parse other options */
	while (ptr) {
		arg = ptr;
		c = nc;
		ptr = strpbrk(arg, ":+@%");
		if (ptr) {
			nc = *ptr;
			*ptr++ = '\0';
		}
		switch (c) {
		case ':':	/* Line number */
			pp->line = strtoul(arg, &tmp, 0);
			if (*tmp != '\0')
				semantic_error("There is non-digit charactor"
						" in line number.");
			break;
		case '+':	/* Byte offset from a symbol */
			pp->offset = strtoul(arg, &tmp, 0);
			if (*tmp != '\0')
				semantic_error("There is non-digit charactor"
						" in offset.");
			break;
		case '@':	/* File name */
			if (pp->file)
				semantic_error("SRC@SRC is not allowed.");
			pp->file = strdup(arg);
			DIE_IF(pp->file == NULL);
			if (ptr)
				semantic_error("@SRC must be the last "
					       "option.");
			break;
		case '%':	/* Probe places */
			if (strcmp(arg, "return") == 0) {
				pp->retprobe = 1;
			} else	/* Others not supported yet */
				semantic_error("%%%s is not supported.", arg);
			break;
		default:
			DIE_IF("Program has a bug.");
			break;
		}
	}

	/* Exclusion check */
	if (pp->line && pp->offset)
		semantic_error("Offset can't be used with line number.");
	if (!pp->line && pp->file && !pp->function)
		semantic_error("File always requires line number.");
	if (pp->offset && !pp->function)
		semantic_error("Offset requires an entry function.");
	if (pp->retprobe && !pp->function)
		semantic_error("Return probe requires an entry function.");
	if ((pp->offset || pp->line) && pp->retprobe)
		semantic_error("Offset/Line can't be used with return probe.");

	pr_debug("symbol:%s file:%s line:%d offset:%d, return:%d\n",
		 pp->function, pp->file, pp->line, pp->offset, pp->retprobe);
}

/* Parse an event definition. Note that any error must die. */
static void parse_probe_event(const char *str)
{
	char *argv[MAX_PROBE_ARGS + 2];	/* Event + probe + args */
	int argc, i;
	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)
		semantic_error("Too many probes");

	/* Separate arguments, similar to argv_split */
	argc = 0;
	do {
		/* Skip separators */
		while (isspace(*str))
			str++;

		/* Add an argument */
		if (*str != '\0') {
			const char *s = str;

			/* Skip the argument */
			while (!isspace(*str) && *str != '\0')
				str++;

			/* Duplicate the argument */
			argv[argc] = strndup(s, str - s);
			if (argv[argc] == NULL)
				die("strndup");
			if (++argc == MAX_PROBE_ARGS)
				semantic_error("Too many arguments");
			pr_debug("argv[%d]=%s\n", argc, argv[argc - 1]);
		}
	} while (*str != '\0');
	if (!argc)
		semantic_error("An empty argument.");

	/* Parse probe point */
	parse_probe_point(argv[0], pp);
	free(argv[0]);
	if (pp->file || pp->line)
		session.need_dwarf = 1;

	/* Copy arguments */
	pp->nr_args = argc - 1;
	if (pp->nr_args > 0) {
		pp->args = (char **)malloc(sizeof(char *) * pp->nr_args);
		if (!pp->args)
			die("malloc");
		memcpy(pp->args, &argv[1], sizeof(char *) * pp->nr_args);
	}

	/* Ensure return probe has no C argument */
	for (i = 0; i < pp->nr_args; i++)
		if (is_c_varname(pp->args[i])) {
			if (pp->retprobe)
				semantic_error("You can't specify local"
						" variable for kretprobe");
			session.need_dwarf = 1;
		}

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

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;
}

#ifndef NO_LIBDWARF
static int open_default_vmlinux(void)
{
	struct utsname uts;
	char fname[MAX_PATH_LEN];
	int fd, ret, i;

	ret = uname(&uts);
	if (ret) {
		pr_debug("uname() failed.\n");
		return -errno;
	}
	session.release = uts.release;
	for (i = 0; i < NR_SEARCH_PATH; i++) {
		ret = snprintf(fname, MAX_PATH_LEN,
			       default_search_path[i], session.release);
		if (ret >= MAX_PATH_LEN || ret < 0) {
			pr_debug("Filename(%d,%s) is too long.\n", i,
				uts.release);
			errno = E2BIG;
			return -E2BIG;
		}
		pr_debug("try to open %s\n", fname);
		fd = open(fname, O_RDONLY);
		if (fd >= 0)
			break;
	}
	return fd;
}
#endif

static const char * const probe_usage[] = {
	"perf probe [<options>] 'PROBEDEF' ['PROBEDEF' ...]",
	"perf probe [<options>] --add 'PROBEDEF' [--add 'PROBEDEF' ...]",
	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", &session.vmlinux, "file",
		"vmlinux/module pathname"),
#endif
	OPT_CALLBACK('a', "add", NULL,
#ifdef NO_LIBDWARF
		"FUNC[+OFFS|%return] [ARG ...]",
#else
		"FUNC[+OFFS|%return|:RLN][@SRC]|SRC:ALN [ARG ...]",
#endif
		"probe point definition, where\n"
		"\t\tGRP:\tGroup name (optional)\n"
		"\t\tNAME:\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 is supported.)\n",
		opt_add_probe_event),
	OPT_END()
};

static int write_new_event(int fd, const char *buf)
{
	int ret;

	ret = write(fd, buf, strlen(buf));
	if (ret <= 0)
		die("Failed to create event.");
	else
		printf("Added new event: %s\n", buf);

	return ret;
}

#define MAX_CMDLEN 256

static int synthesize_probe_event(struct probe_point *pp)
{
	char *buf;
	int i, len, ret;
	pp->probes[0] = buf = zalloc(MAX_CMDLEN);
	if (!buf)
		die("Failed to allocate memory by zalloc.");
	ret = snprintf(buf, MAX_CMDLEN, "%s+%d", pp->function, pp->offset);
	if (ret <= 0 || ret >= MAX_CMDLEN)
		goto error;
	len = ret;

	for (i = 0; i < pp->nr_args; i++) {
		ret = snprintf(&buf[len], MAX_CMDLEN - len, " %s",
			       pp->args[i]);
		if (ret <= 0 || ret >= MAX_CMDLEN - len)
			goto error;
		len += ret;
	}
	pp->found = 1;
	return pp->found;
error:
	free(pp->probes[0]);
	if (ret > 0)
		ret = -E2BIG;
	return ret;
}

int cmd_probe(int argc, const char **argv, const char *prefix __used)
{
	int i, j, fd, ret;
	struct probe_point *pp;
	char buf[MAX_CMDLEN];

	argc = parse_options(argc, argv, options, probe_usage,
			     PARSE_OPT_STOP_AT_NON_OPTION);
	for (i = 0; i < argc; i++)
		parse_probe_event(argv[i]);

	if (session.nr_probe == 0)
		usage_with_options(probe_usage, options);

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

	if (session.vmlinux)
		fd = open(session.vmlinux, O_RDONLY);
	else
		fd = open_default_vmlinux();
	if (fd < 0) {
		if (session.need_dwarf)
			die("Could not open vmlinux/module file.");

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

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

		lseek(fd, SEEK_SET, 0);
		ret = find_probepoint(fd, pp);
		if (ret < 0) {
			if (session.need_dwarf)
				die("Could not analyze debuginfo.");

			pr_warning("An error occurred in debuginfo analysis. Try to use symbols.\n");
			break;
		}
		if (ret == 0)	/* No error but failed to find probe point. */
			die("No probe point found.");
	}
	close(fd);

end_dwarf:
#endif /* !NO_LIBDWARF */

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

		ret = synthesize_probe_event(pp);
		if (ret == -E2BIG)
			semantic_error("probe point is too long.");
		else if (ret < 0)
			die("Failed to synthesize a probe point.");
	}

	/* Settng up probe points */
	snprintf(buf, MAX_CMDLEN, "%s/../kprobe_events", debugfs_path);
	fd = open(buf, O_WRONLY, O_APPEND);
	if (fd < 0) {
		if (errno == ENOENT)
			die("kprobe_events file does not exist - please rebuild with CONFIG_KPROBE_TRACER.");
		else
			die("Could not open kprobe_events file: %s",
			    strerror(errno));
	}
	for (j = 0; j < session.nr_probe; j++) {
		pp = &session.probes[j];
		if (pp->found == 1) {
			snprintf(buf, MAX_CMDLEN, "%c:%s/%s_%x %s\n",
				pp->retprobe ? 'r' : 'p', PERFPROBE_GROUP,
				pp->function, pp->offset, pp->probes[0]);
			write_new_event(fd, buf);
		} else
			for (i = 0; i < pp->found; i++) {
				snprintf(buf, MAX_CMDLEN, "%c:%s/%s_%x_%d %s\n",
					pp->retprobe ? 'r' : 'p',
					PERFPROBE_GROUP,
					pp->function, pp->offset, i,
					pp->probes[0]);
				write_new_event(fd, buf);
			}
	}
	close(fd);
	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"
89c69c0e MH	38	#include "util/event.h"
89c69c0e MH	39	#include "util/debug.h"
4ea42b18 MH	40	#include "util/parse-options.h"
	41	#include "util/parse-events.h" /* For debugfs_path */
	42	#include "util/probe-finder.h"
	43
	44	/* Default vmlinux search paths */
	45	#define NR_SEARCH_PATH 3
	46	const char *default_search_path[NR_SEARCH_PATH] = {
	47	"/lib/modules/%s/build/vmlinux", /* Custom build kernel */
	48	"/usr/lib/debug/lib/modules/%s/vmlinux", /* Red Hat debuginfo */
	49	"/boot/vmlinux-debug-%s", /* Ubuntu */
	50	};
	51
	52	#define MAX_PATH_LEN 256
	53	#define MAX_PROBES 128
074fc0e4	54	#define MAX_PROBE_ARGS 128
91365bbe	55	#define PERFPROBE_GROUP "probe"
4ea42b18 MH	56
	57	/* Session management structure */
	58	static struct {
	59	char *vmlinux;
	60	char *release;
23e8ec0d	61	int need_dwarf;
4ea42b18 MH	62	int nr_probe;
4ea42b18 MH	63	struct probe_point probes[MAX_PROBES];
4ea42b18 MH	64	} session;
4ea42b18 MH	65
074fc0e4	66	#define semantic_error(msg ...) die("Semantic error :" msg)
4ea42b18	67
253977b0 MH	68	/* Parse probe point. Return 1 if return probe */
	69	static void parse_probe_point(char arg, struct probe_point pp)
	70	{
	71	char ptr, tmp;
12e4db47	72	char c, nc = 0;
253977b0 MH	73	/*
	74	* <Syntax>
	75	* perf probe SRC:LN
	76	* perf probe FUNC[+OFFS\|%return][@SRC]
	77	*/
	78
	79	ptr = strpbrk(arg, ":+@%");
	80	if (ptr) {
	81	nc = *ptr;
	82	*ptr++ = '\0';
	83	}
	84
	85	/* Check arg is function or file and copy it */
	86	if (strchr(arg, '.')) /* File */
	87	pp->file = strdup(arg);
	88	else /* Function */
	89	pp->function = strdup(arg);
	90	DIE_IF(pp->file == NULL && pp->function == NULL);
	91
	92	/* Parse other options */
	93	while (ptr) {
	94	arg = ptr;
	95	c = nc;
	96	ptr = strpbrk(arg, ":+@%");
	97	if (ptr) {
	98	nc = *ptr;
	99	*ptr++ = '\0';
	100	}
	101	switch (c) {
	102	case ':': /* Line number */
	103	pp->line = strtoul(arg, &tmp, 0);
	104	if (*tmp != '\0')
	105	semantic_error("There is non-digit charactor"
	106	" in line number.");
	107	break;
	108	case '+': /* Byte offset from a symbol */
	109	pp->offset = strtoul(arg, &tmp, 0);
	110	if (*tmp != '\0')
	111	semantic_error("There is non-digit charactor"
	112	" in offset.");
	113	break;
	114	case '@': /* File name */
	115	if (pp->file)
	116	semantic_error("SRC@SRC is not allowed.");
	117	pp->file = strdup(arg);
	118	DIE_IF(pp->file == NULL);
	119	if (ptr)
	120	semantic_error("@SRC must be the last "
	121	"option.");
	122	break;
	123	case '%': /* Probe places */
	124	if (strcmp(arg, "return") == 0) {
	125	pp->retprobe = 1;
	126	} else /* Others not supported yet */
	127	semantic_error("%%%s is not supported.", arg);
	128	break;
	129	default:
	130	DIE_IF("Program has a bug.");
	131	break;
	132	}
	133	}
	134
	135	/* Exclusion check */
b0ef0732 MH	136	if (pp->line && pp->offset)
b0ef0732 MH	137	semantic_error("Offset can't be used with line number.");
253977b0 MH	138	if (!pp->line && pp->file && !pp->function)
	139	semantic_error("File always requires line number.");
	140	if (pp->offset && !pp->function)
	141	semantic_error("Offset requires an entry function.");
	142	if (pp->retprobe && !pp->function)
	143	semantic_error("Return probe requires an entry function.");
b0ef0732 MH	144	if ((pp->offset \|\| pp->line) && pp->retprobe)
b0ef0732 MH	145	semantic_error("Offset/Line can't be used with return probe.");
253977b0 MH	146
	147	pr_debug("symbol:%s file:%s line:%d offset:%d, return:%d\n",
	148	pp->function, pp->file, pp->line, pp->offset, pp->retprobe);
	149	}
	150
	151	/* Parse an event definition. Note that any error must die. */
	152	static void parse_probe_event(const char *str)
4ea42b18 MH	153	{
	154	char argv[MAX_PROBE_ARGS + 2]; / Event + probe + args */
	155	int argc, i;
4ea42b18	156	struct probe_point *pp = &session.probes[session.nr_probe];
4ea42b18	157
b7cb10e7	158	pr_debug("probe-definition(%d): %s\n", session.nr_probe, str);
4ea42b18 MH	159	if (++session.nr_probe == MAX_PROBES)
	160	semantic_error("Too many probes");
	161
	162	/* Separate arguments, similar to argv_split */
	163	argc = 0;
	164	do {
	165	/* Skip separators */
	166	while (isspace(*str))
	167	str++;
	168
	169	/* Add an argument */
	170	if (*str != '\0') {
	171	const char *s = str;
	172
	173	/* Skip the argument */
	174	while (!isspace(str) && str != '\0')
	175	str++;
	176
	177	/* Duplicate the argument */
	178	argv[argc] = strndup(s, str - s);
	179	if (argv[argc] == NULL)
074fc0e4	180	die("strndup");
4ea42b18 MH	181	if (++argc == MAX_PROBE_ARGS)
4ea42b18 MH	182	semantic_error("Too many arguments");
b7cb10e7	183	pr_debug("argv[%d]=%s\n", argc, argv[argc - 1]);
4ea42b18 MH	184	}
4ea42b18 MH	185	} while (*str != '\0');
253977b0 MH	186	if (!argc)
253977b0 MH	187	semantic_error("An empty argument.");
4ea42b18 MH	188
4ea42b18 MH	189	/* Parse probe point */
253977b0 MH	190	parse_probe_point(argv[0], pp);
253977b0 MH	191	free(argv[0]);
a225a1d9	192	if (pp->file \|\| pp->line)
23e8ec0d	193	session.need_dwarf = 1;
4ea42b18 MH	194
4ea42b18 MH	195	/* Copy arguments */
253977b0	196	pp->nr_args = argc - 1;
4ea42b18 MH	197	if (pp->nr_args > 0) {
	198	pp->args = (char *)malloc(sizeof(char ) * pp->nr_args);
	199	if (!pp->args)
074fc0e4	200	die("malloc");
253977b0	201	memcpy(pp->args, &argv[1], sizeof(char ) pp->nr_args);
4ea42b18 MH	202	}
	203
	204	/* Ensure return probe has no C argument */
23e8ec0d MH	205	for (i = 0; i < pp->nr_args; i++)
23e8ec0d MH	206	if (is_c_varname(pp->args[i])) {
253977b0	207	if (pp->retprobe)
4ea42b18 MH	208	semantic_error("You can't specify local"
4ea42b18 MH	209	" variable for kretprobe");
23e8ec0d MH	210	session.need_dwarf = 1;
	211	}
	212
b7cb10e7	213	pr_debug("%d arguments\n", pp->nr_args);
46ab4926 MH	214	}
46ab4926 MH	215
253977b0	216	static int opt_add_probe_event(const struct option *opt __used,
46ab4926 MH	217	const char *str, int unset __used)
	218	{
	219	if (str)
253977b0	220	parse_probe_event(str);
4ea42b18 MH	221	return 0;
	222	}
	223
23e8ec0d	224	#ifndef NO_LIBDWARF
4ea42b18 MH	225	static int open_default_vmlinux(void)
	226	{
	227	struct utsname uts;
	228	char fname[MAX_PATH_LEN];
	229	int fd, ret, i;
	230
	231	ret = uname(&uts);
	232	if (ret) {
b7cb10e7	233	pr_debug("uname() failed.\n");
4ea42b18 MH	234	return -errno;
	235	}
	236	session.release = uts.release;
	237	for (i = 0; i < NR_SEARCH_PATH; i++) {
	238	ret = snprintf(fname, MAX_PATH_LEN,
	239	default_search_path[i], session.release);
	240	if (ret >= MAX_PATH_LEN \|\| ret < 0) {
b7cb10e7	241	pr_debug("Filename(%d,%s) is too long.\n", i,
89c69c0e	242	uts.release);
4ea42b18 MH	243	errno = E2BIG;
	244	return -E2BIG;
	245	}
b7cb10e7	246	pr_debug("try to open %s\n", fname);
4ea42b18 MH	247	fd = open(fname, O_RDONLY);
	248	if (fd >= 0)
	249	break;
	250	}
	251	return fd;
	252	}
23e8ec0d	253	#endif
4ea42b18 MH	254
4ea42b18 MH	255	static const char * const probe_usage[] = {
46ab4926 MH	256	"perf probe [<options>] 'PROBEDEF' ['PROBEDEF' ...]",
46ab4926 MH	257	"perf probe [<options>] --add 'PROBEDEF' [--add 'PROBEDEF' ...]",
4ea42b18 MH	258	NULL
	259	};
	260
	261	static const struct option options[] = {
89c69c0e MH	262	OPT_BOOLEAN('v', "verbose", &verbose,
89c69c0e MH	263	"be more verbose (show parsed arguments, etc)"),
23e8ec0d	264	#ifndef NO_LIBDWARF
4ea42b18 MH	265	OPT_STRING('k', "vmlinux", &session.vmlinux, "file",
4ea42b18 MH	266	"vmlinux/module pathname"),
23e8ec0d	267	#endif
46ab4926	268	OPT_CALLBACK('a', "add", NULL,
23e8ec0d	269	#ifdef NO_LIBDWARF
253977b0	270	"FUNC[+OFFS\|%return] [ARG ...]",
23e8ec0d	271	#else
b0ef0732	272	"FUNC[+OFFS\|%return\|:RLN][@SRC]\|SRC:ALN [ARG ...]",
23e8ec0d	273	#endif
4ea42b18	274	"probe point definition, where\n"
4ea42b18 MH	275	"\t\tGRP:\tGroup name (optional)\n"
	276	"\t\tNAME:\tEvent name\n"
	277	"\t\tFUNC:\tFunction name\n"
	278	"\t\tOFFS:\tOffset from function entry (in byte)\n"
253977b0	279	"\t\t%return:\tPut the probe at function return\n"
23e8ec0d MH	280	#ifdef NO_LIBDWARF
	281	"\t\tARG:\tProbe argument (only \n"
	282	#else
4ea42b18	283	"\t\tSRC:\tSource code path\n"
b0ef0732 MH	284	"\t\tRLN:\tRelative line number from function entry.\n"
b0ef0732 MH	285	"\t\tALN:\tAbsolute line number in file.\n"
4ea42b18	286	"\t\tARG:\tProbe argument (local variable name or\n"
23e8ec0d	287	#endif
4ea42b18	288	"\t\t\tkprobe-tracer argument format is supported.)\n",
253977b0	289	opt_add_probe_event),
4ea42b18 MH	290	OPT_END()
	291	};
	292
	293	static int write_new_event(int fd, const char *buf)
	294	{
	295	int ret;
	296
4ea42b18 MH	297	ret = write(fd, buf, strlen(buf));
4ea42b18 MH	298	if (ret <= 0)
a7f4328b MH	299	die("Failed to create event.");
	300	else
	301	printf("Added new event: %s\n", buf);
4ea42b18 MH	302
	303	return ret;
	304	}
	305
	306	#define MAX_CMDLEN 256
	307
253977b0	308	static int synthesize_probe_event(struct probe_point *pp)
4ea42b18 MH	309	{
	310	char *buf;
	311	int i, len, ret;
36479484	312	pp->probes[0] = buf = zalloc(MAX_CMDLEN);
4ea42b18	313	if (!buf)
36479484	314	die("Failed to allocate memory by zalloc.");
4ea42b18 MH	315	ret = snprintf(buf, MAX_CMDLEN, "%s+%d", pp->function, pp->offset);
	316	if (ret <= 0 \|\| ret >= MAX_CMDLEN)
	317	goto error;
	318	len = ret;
	319
	320	for (i = 0; i < pp->nr_args; i++) {
	321	ret = snprintf(&buf[len], MAX_CMDLEN - len, " %s",
	322	pp->args[i]);
	323	if (ret <= 0 \|\| ret >= MAX_CMDLEN - len)
	324	goto error;
	325	len += ret;
	326	}
	327	pp->found = 1;
	328	return pp->found;
	329	error:
	330	free(pp->probes[0]);
	331	if (ret > 0)
	332	ret = -E2BIG;
	333	return ret;
	334	}
	335
	336	int cmd_probe(int argc, const char *argv, const char prefix __used)
	337	{
23e8ec0d	338	int i, j, fd, ret;
4ea42b18 MH	339	struct probe_point *pp;
	340	char buf[MAX_CMDLEN];
	341
	342	argc = parse_options(argc, argv, options, probe_usage,
46ab4926 MH	343	PARSE_OPT_STOP_AT_NON_OPTION);
	344	for (i = 0; i < argc; i++)
	345	parse_probe_event(argv[i]);
	346
	347	if (session.nr_probe == 0)
4ea42b18 MH	348	usage_with_options(probe_usage, options);
4ea42b18 MH	349
23e8ec0d	350	if (session.need_dwarf)
a225a1d9 MH	351	#ifdef NO_LIBDWARF
	352	semantic_error("Debuginfo-analysis is not supported");
	353	#else /* !NO_LIBDWARF */
	354	pr_info("Some probes require debuginfo.\n");
4ea42b18 MH	355
	356	if (session.vmlinux)
	357	fd = open(session.vmlinux, O_RDONLY);
	358	else
	359	fd = open_default_vmlinux();
a225a1d9 MH	360	if (fd < 0) {
	361	if (session.need_dwarf)
	362	die("Could not open vmlinux/module file.");
	363
	364	pr_warning("Could not open vmlinux/module file."
	365	" Try to use symbols.\n");
	366	goto end_dwarf;
	367	}
4ea42b18 MH	368
	369	/* Searching probe points */
	370	for (j = 0; j < session.nr_probe; j++) {
	371	pp = &session.probes[j];
	372	if (pp->found)
	373	continue;
	374
	375	lseek(fd, SEEK_SET, 0);
	376	ret = find_probepoint(fd, pp);
a225a1d9 MH	377	if (ret < 0) {
	378	if (session.need_dwarf)
	379	die("Could not analyze debuginfo.");
	380
	381	pr_warning("An error occurred in debuginfo analysis. Try to use symbols.\n");
	382	break;
	383	}
	384	if (ret == 0) /* No error but failed to find probe point. */
	385	die("No probe point found.");
4ea42b18 MH	386	}
	387	close(fd);
	388
a225a1d9	389	end_dwarf:
23e8ec0d MH	390	#endif /* !NO_LIBDWARF */
23e8ec0d MH	391
a225a1d9 MH	392	/* Synthesize probes without dwarf */
	393	for (j = 0; j < session.nr_probe; j++) {
	394	pp = &session.probes[j];
	395	if (pp->found) /* This probe is already found. */
	396	continue;
	397
	398	ret = synthesize_probe_event(pp);
	399	if (ret == -E2BIG)
	400	semantic_error("probe point is too long.");
	401	else if (ret < 0)
	402	die("Failed to synthesize a probe point.");
	403	}
	404
4ea42b18 MH	405	/* Settng up probe points */
	406	snprintf(buf, MAX_CMDLEN, "%s/../kprobe_events", debugfs_path);
	407	fd = open(buf, O_WRONLY, O_APPEND);
a7f4328b MH	408	if (fd < 0) {
	409	if (errno == ENOENT)
	410	die("kprobe_events file does not exist - please rebuild with CONFIG_KPROBE_TRACER.");
	411	else
	412	die("Could not open kprobe_events file: %s",
	413	strerror(errno));
	414	}
4ea42b18 MH	415	for (j = 0; j < session.nr_probe; j++) {
	416	pp = &session.probes[j];
	417	if (pp->found == 1) {
253977b0 MH	418	snprintf(buf, MAX_CMDLEN, "%c:%s/%s_%x %s\n",
	419	pp->retprobe ? 'r' : 'p', PERFPROBE_GROUP,
	420	pp->function, pp->offset, pp->probes[0]);
4ea42b18 MH	421	write_new_event(fd, buf);
	422	} else
	423	for (i = 0; i < pp->found; i++) {
253977b0 MH	424	snprintf(buf, MAX_CMDLEN, "%c:%s/%s_%x_%d %s\n",
	425	pp->retprobe ? 'r' : 'p',
	426	PERFPROBE_GROUP,
	427	pp->function, pp->offset, i,
	428	pp->probes[0]);
4ea42b18 MH	429	write_new_event(fd, buf);
	430	}
	431	}
	432	close(fd);
	433	return 0;
	434	}
	435