tools/perf/util/probe-file.c - linux - Git at Google

 /*
  * probe-file.c : operate ftrace k/uprobe events files
  *
  * Written by Masami Hiramatsu <masami.hiramatsu.pt@hitachi.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.
  *
  */
 #include "util.h"
 #include "event.h"
 #include "strlist.h"
 #include "debug.h"
 #include "cache.h"
 #include "color.h"
 #include "symbol.h"
 #include "thread.h"
 #include <api/fs/tracing_path.h>
 #include "probe-event.h"
 #include "probe-file.h"
 #include "session.h"

 #define MAX_CMDLEN 256

 static void print_open_warning(int err, bool uprobe)
 {
 	char sbuf[STRERR_BUFSIZE];

 	if (err == -ENOENT) {
 		const char *config;

 		if (uprobe)
 			config = "CONFIG_UPROBE_EVENTS";
 		else
 			config = "CONFIG_KPROBE_EVENTS";

 		pr_warning("%cprobe_events file does not exist"
 			   " - please rebuild kernel with %s.\n",
 			   uprobe ? 'u' : 'k', config);
 	} else if (err == -ENOTSUP)
 		pr_warning("Tracefs or debugfs is not mounted.\n");
 	else
 		pr_warning("Failed to open %cprobe_events: %s\n",
 			   uprobe ? 'u' : 'k',
 			   strerror_r(-err, sbuf, sizeof(sbuf)));
 }

 static void print_both_open_warning(int kerr, int uerr)
 {
 	/* Both kprobes and uprobes are disabled, warn it. */
 	if (kerr == -ENOTSUP && uerr == -ENOTSUP)
 		pr_warning("Tracefs or debugfs is not mounted.\n");
 	else if (kerr == -ENOENT && uerr == -ENOENT)
 		pr_warning("Please rebuild kernel with CONFIG_KPROBE_EVENTS "
 			   "or/and CONFIG_UPROBE_EVENTS.\n");
 	else {
 		char sbuf[STRERR_BUFSIZE];
 		pr_warning("Failed to open kprobe events: %s.\n",
 			   strerror_r(-kerr, sbuf, sizeof(sbuf)));
 		pr_warning("Failed to open uprobe events: %s.\n",
 			   strerror_r(-uerr, sbuf, sizeof(sbuf)));
 	}
 }

 static int open_probe_events(const char *trace_file, bool readwrite)
 {
 	char buf[PATH_MAX];
 	const char *tracing_dir = "";
 	int ret;

 	ret = e_snprintf(buf, PATH_MAX, "%s/%s%s",
 			 tracing_path, tracing_dir, trace_file);
 	if (ret >= 0) {
 		pr_debug("Opening %s write=%d\n", buf, readwrite);
 		if (readwrite && !probe_event_dry_run)
 			ret = open(buf, O_RDWR | O_APPEND, 0);
 		else
 			ret = open(buf, O_RDONLY, 0);

 		if (ret < 0)
 			ret = -errno;
 	}
 	return ret;
 }

 static int open_kprobe_events(bool readwrite)
 {
 	return open_probe_events("kprobe_events", readwrite);
 }

 static int open_uprobe_events(bool readwrite)
 {
 	return open_probe_events("uprobe_events", readwrite);
 }

 int probe_file__open(int flag)
 {
 	int fd;

 	if (flag & PF_FL_UPROBE)
 		fd = open_uprobe_events(flag & PF_FL_RW);
 	else
 		fd = open_kprobe_events(flag & PF_FL_RW);
 	if (fd < 0)
 		print_open_warning(fd, flag & PF_FL_UPROBE);

 	return fd;
 }

 int probe_file__open_both(int *kfd, int *ufd, int flag)
 {
 	if (!kfd || !ufd)
 		return -EINVAL;

 	*kfd = open_kprobe_events(flag & PF_FL_RW);
 	*ufd = open_uprobe_events(flag & PF_FL_RW);
 	if (*kfd < 0 && *ufd < 0) {
 		print_both_open_warning(*kfd, *ufd);
 		return *kfd;
 	}

 	return 0;
 }

 /* Get raw string list of current kprobe_events  or uprobe_events */
 struct strlist *probe_file__get_rawlist(int fd)
 {
 	int ret, idx;
 	FILE *fp;
 	char buf[MAX_CMDLEN];
 	char *p;
 	struct strlist *sl;

 	if (fd < 0)
 		return NULL;

 	sl = strlist__new(NULL, NULL);

 	fp = fdopen(dup(fd), "r");
 	while (!feof(fp)) {
 		p = fgets(buf, MAX_CMDLEN, fp);
 		if (!p)
 			break;

 		idx = strlen(p) - 1;
 		if (p[idx] == '\n')
 			p[idx] = '\0';
 		ret = strlist__add(sl, buf);
 		if (ret < 0) {
 			pr_debug("strlist__add failed (%d)\n", ret);
 			strlist__delete(sl);
 			return NULL;
 		}
 	}
 	fclose(fp);

 	return sl;
 }

 static struct strlist *__probe_file__get_namelist(int fd, bool include_group)
 {
 	char buf[128];
 	struct strlist *sl, *rawlist;
 	struct str_node *ent;
 	struct probe_trace_event tev;
 	int ret = 0;

 	memset(&tev, 0, sizeof(tev));
 	rawlist = probe_file__get_rawlist(fd);
 	if (!rawlist)
 		return NULL;
 	sl = strlist__new(NULL, NULL);
 	strlist__for_each(ent, rawlist) {
 		ret = parse_probe_trace_command(ent->s, &tev);
 		if (ret < 0)
 			break;
 		if (include_group) {
 			ret = e_snprintf(buf, 128, "%s:%s", tev.group,
 					tev.event);
 			if (ret >= 0)
 				ret = strlist__add(sl, buf);
 		} else
 			ret = strlist__add(sl, tev.event);
 		clear_probe_trace_event(&tev);
 		if (ret < 0)
 			break;
 	}
 	strlist__delete(rawlist);

 	if (ret < 0) {
 		strlist__delete(sl);
 		return NULL;
 	}
 	return sl;
 }

 /* Get current perf-probe event names */
 struct strlist *probe_file__get_namelist(int fd)
 {
 	return __probe_file__get_namelist(fd, false);
 }

 int probe_file__add_event(int fd, struct probe_trace_event *tev)
 {
 	int ret = 0;
 	char *buf = synthesize_probe_trace_command(tev);
 	char sbuf[STRERR_BUFSIZE];

 	if (!buf) {
 		pr_debug("Failed to synthesize probe trace event.\n");
 		return -EINVAL;
 	}

 	pr_debug("Writing event: %s\n", buf);
 	if (!probe_event_dry_run) {
 		ret = write(fd, buf, strlen(buf));
 		if (ret <= 0) {
 			ret = -errno;
 			pr_warning("Failed to write event: %s\n",
 				   strerror_r(errno, sbuf, sizeof(sbuf)));
 		}
 	}
 	free(buf);

 	return ret;
 }

 static int __del_trace_probe_event(int fd, struct str_node *ent)
 {
 	char *p;
 	char buf[128];
 	int ret;

 	/* Convert from perf-probe event to trace-probe event */
 	ret = e_snprintf(buf, 128, "-:%s", ent->s);
 	if (ret < 0)
 		goto error;

 	p = strchr(buf + 2, ':');
 	if (!p) {
 		pr_debug("Internal error: %s should have ':' but not.\n",
 			 ent->s);
 		ret = -ENOTSUP;
 		goto error;
 	}
 	*p = '/';

 	pr_debug("Writing event: %s\n", buf);
 	ret = write(fd, buf, strlen(buf));
 	if (ret < 0) {
 		ret = -errno;
 		goto error;
 	}

 	return 0;
 error:
 	pr_warning("Failed to delete event: %s\n",
 		   strerror_r(-ret, buf, sizeof(buf)));
 	return ret;
 }

 int probe_file__get_events(int fd, struct strfilter *filter,
 			   struct strlist *plist)
 {
 	struct strlist *namelist;
 	struct str_node *ent;
 	const char *p;
 	int ret = -ENOENT;

 	if (!plist)
 		return -EINVAL;

 	namelist = __probe_file__get_namelist(fd, true);
 	if (!namelist)
 		return -ENOENT;

 	strlist__for_each(ent, namelist) {
 		p = strchr(ent->s, ':');
 		if ((p && strfilter__compare(filter, p + 1)) ||
 		    strfilter__compare(filter, ent->s)) {
 			strlist__add(plist, ent->s);
 			ret = 0;
 		}
 	}
 	strlist__delete(namelist);

 	return ret;
 }

 int probe_file__del_strlist(int fd, struct strlist *namelist)
 {
 	int ret = 0;
 	struct str_node *ent;

 	strlist__for_each(ent, namelist) {
 		ret = __del_trace_probe_event(fd, ent);
 		if (ret < 0)
 			break;
 	}
 	return ret;
 }

 int probe_file__del_events(int fd, struct strfilter *filter)
 {
 	struct strlist *namelist;
 	int ret;

 	namelist = strlist__new(NULL, NULL);
 	if (!namelist)
 		return -ENOMEM;

 	ret = probe_file__get_events(fd, filter, namelist);
 	if (ret < 0)
 		return ret;

 	ret = probe_file__del_strlist(fd, namelist);
 	strlist__delete(namelist);

 	return ret;
 }
	/*
	* probe-file.c : operate ftrace k/uprobe events files
	*
	* Written by Masami Hiramatsu <masami.hiramatsu.pt@hitachi.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.
	*
	*/
	#include "util.h"
	#include "event.h"
	#include "strlist.h"
	#include "debug.h"
	#include "cache.h"
	#include "color.h"
	#include "symbol.h"
	#include "thread.h"
	#include <api/fs/tracing_path.h>
	#include "probe-event.h"
	#include "probe-file.h"
	#include "session.h"

	#define MAX_CMDLEN 256

	static void print_open_warning(int err, bool uprobe)
	{
	char sbuf[STRERR_BUFSIZE];

	if (err == -ENOENT) {
	const char *config;

	if (uprobe)
	config = "CONFIG_UPROBE_EVENTS";
	else
	config = "CONFIG_KPROBE_EVENTS";

	pr_warning("%cprobe_events file does not exist"
	" - please rebuild kernel with %s.\n",
	uprobe ? 'u' : 'k', config);
	} else if (err == -ENOTSUP)
	pr_warning("Tracefs or debugfs is not mounted.\n");
	else
	pr_warning("Failed to open %cprobe_events: %s\n",
	uprobe ? 'u' : 'k',
	strerror_r(-err, sbuf, sizeof(sbuf)));
	}

	static void print_both_open_warning(int kerr, int uerr)
	{
	/* Both kprobes and uprobes are disabled, warn it. */
	if (kerr == -ENOTSUP && uerr == -ENOTSUP)
	pr_warning("Tracefs or debugfs is not mounted.\n");
	else if (kerr == -ENOENT && uerr == -ENOENT)
	pr_warning("Please rebuild kernel with CONFIG_KPROBE_EVENTS "
	"or/and CONFIG_UPROBE_EVENTS.\n");
	else {
	char sbuf[STRERR_BUFSIZE];
	pr_warning("Failed to open kprobe events: %s.\n",
	strerror_r(-kerr, sbuf, sizeof(sbuf)));
	pr_warning("Failed to open uprobe events: %s.\n",
	strerror_r(-uerr, sbuf, sizeof(sbuf)));
	}
	}

	static int open_probe_events(const char *trace_file, bool readwrite)
	{
	char buf[PATH_MAX];
	const char *tracing_dir = "";
	int ret;

	ret = e_snprintf(buf, PATH_MAX, "%s/%s%s",
	tracing_path, tracing_dir, trace_file);
	if (ret >= 0) {
	pr_debug("Opening %s write=%d\n", buf, readwrite);
	if (readwrite && !probe_event_dry_run)
	ret = open(buf, O_RDWR \| O_APPEND, 0);
	else
	ret = open(buf, O_RDONLY, 0);

	if (ret < 0)
	ret = -errno;
	}
	return ret;
	}

	static int open_kprobe_events(bool readwrite)
	{
	return open_probe_events("kprobe_events", readwrite);
	}

	static int open_uprobe_events(bool readwrite)
	{
	return open_probe_events("uprobe_events", readwrite);
	}

	int probe_file__open(int flag)
	{
	int fd;

	if (flag & PF_FL_UPROBE)
	fd = open_uprobe_events(flag & PF_FL_RW);
	else
	fd = open_kprobe_events(flag & PF_FL_RW);
	if (fd < 0)
	print_open_warning(fd, flag & PF_FL_UPROBE);

	return fd;
	}

	int probe_file__open_both(int kfd, int ufd, int flag)
	{
	if (!kfd \|\| !ufd)
	return -EINVAL;

	*kfd = open_kprobe_events(flag & PF_FL_RW);
	*ufd = open_uprobe_events(flag & PF_FL_RW);
	if (kfd < 0 && ufd < 0) {
	print_both_open_warning(kfd, ufd);
	return *kfd;
	}

	return 0;
	}

	/* Get raw string list of current kprobe_events or uprobe_events */
	struct strlist *probe_file__get_rawlist(int fd)
	{
	int ret, idx;
	FILE *fp;
	char buf[MAX_CMDLEN];
	char *p;
	struct strlist *sl;

	if (fd < 0)
	return NULL;

	sl = strlist__new(NULL, NULL);

	fp = fdopen(dup(fd), "r");
	while (!feof(fp)) {
	p = fgets(buf, MAX_CMDLEN, fp);
	if (!p)
	break;

	idx = strlen(p) - 1;
	if (p[idx] == '\n')
	p[idx] = '\0';
	ret = strlist__add(sl, buf);
	if (ret < 0) {
	pr_debug("strlist__add failed (%d)\n", ret);
	strlist__delete(sl);
	return NULL;
	}
	}
	fclose(fp);

	return sl;
	}

	static struct strlist *__probe_file__get_namelist(int fd, bool include_group)
	{
	char buf[128];
	struct strlist sl, rawlist;
	struct str_node *ent;
	struct probe_trace_event tev;
	int ret = 0;

	memset(&tev, 0, sizeof(tev));
	rawlist = probe_file__get_rawlist(fd);
	if (!rawlist)
	return NULL;
	sl = strlist__new(NULL, NULL);
	strlist__for_each(ent, rawlist) {
	ret = parse_probe_trace_command(ent->s, &tev);
	if (ret < 0)
	break;
	if (include_group) {
	ret = e_snprintf(buf, 128, "%s:%s", tev.group,
	tev.event);
	if (ret >= 0)
	ret = strlist__add(sl, buf);
	} else
	ret = strlist__add(sl, tev.event);
	clear_probe_trace_event(&tev);
	if (ret < 0)
	break;
	}
	strlist__delete(rawlist);

	if (ret < 0) {
	strlist__delete(sl);
	return NULL;
	}
	return sl;
	}

	/* Get current perf-probe event names */
	struct strlist *probe_file__get_namelist(int fd)
	{
	return __probe_file__get_namelist(fd, false);
	}

	int probe_file__add_event(int fd, struct probe_trace_event *tev)
	{
	int ret = 0;
	char *buf = synthesize_probe_trace_command(tev);
	char sbuf[STRERR_BUFSIZE];

	if (!buf) {
	pr_debug("Failed to synthesize probe trace event.\n");
	return -EINVAL;
	}

	pr_debug("Writing event: %s\n", buf);
	if (!probe_event_dry_run) {
	ret = write(fd, buf, strlen(buf));
	if (ret <= 0) {
	ret = -errno;
	pr_warning("Failed to write event: %s\n",
	strerror_r(errno, sbuf, sizeof(sbuf)));
	}
	}
	free(buf);

	return ret;
	}

	static int __del_trace_probe_event(int fd, struct str_node *ent)
	{
	char *p;
	char buf[128];
	int ret;

	/* Convert from perf-probe event to trace-probe event */
	ret = e_snprintf(buf, 128, "-:%s", ent->s);
	if (ret < 0)
	goto error;

	p = strchr(buf + 2, ':');
	if (!p) {
	pr_debug("Internal error: %s should have ':' but not.\n",
	ent->s);
	ret = -ENOTSUP;
	goto error;
	}
	*p = '/';

	pr_debug("Writing event: %s\n", buf);
	ret = write(fd, buf, strlen(buf));
	if (ret < 0) {
	ret = -errno;
	goto error;
	}

	return 0;
	error:
	pr_warning("Failed to delete event: %s\n",
	strerror_r(-ret, buf, sizeof(buf)));
	return ret;
	}

	int probe_file__get_events(int fd, struct strfilter *filter,
	struct strlist *plist)
	{
	struct strlist *namelist;
	struct str_node *ent;
	const char *p;
	int ret = -ENOENT;

	if (!plist)
	return -EINVAL;

	namelist = __probe_file__get_namelist(fd, true);
	if (!namelist)
	return -ENOENT;

	strlist__for_each(ent, namelist) {
	p = strchr(ent->s, ':');
	if ((p && strfilter__compare(filter, p + 1)) \|\|
	strfilter__compare(filter, ent->s)) {
	strlist__add(plist, ent->s);
	ret = 0;
	}
	}
	strlist__delete(namelist);

	return ret;
	}

	int probe_file__del_strlist(int fd, struct strlist *namelist)
	{
	int ret = 0;
	struct str_node *ent;

	strlist__for_each(ent, namelist) {
	ret = __del_trace_probe_event(fd, ent);
	if (ret < 0)
	break;
	}
	return ret;
	}

	int probe_file__del_events(int fd, struct strfilter *filter)
	{
	struct strlist *namelist;
	int ret;

	namelist = strlist__new(NULL, NULL);
	if (!namelist)
	return -ENOMEM;

	ret = probe_file__get_events(fd, filter, namelist);
	if (ret < 0)
	return ret;

	ret = probe_file__del_strlist(fd, namelist);
	strlist__delete(namelist);

	return ret;
	}