tools/perf/builtin-probe.c - linux - Git at Google

 /*
  * 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/debugfs.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 (debugfs_valid_mountpoint(debugfs_path) < 0)
 		die("Failed to find debugfs path.");

 	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;
 }
	/*
	* 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/debugfs.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 (debugfs_valid_mountpoint(debugfs_path) < 0)
	die("Failed to find debugfs path.");

	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;
	}