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      1 /*
      2  * Copyright (C) 2008,2009, Steven Rostedt <srostedt (at) redhat.com>
      3  *
      4  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
      5  *
      6  * This program is free software; you can redistribute it and/or modify
      7  * it under the terms of the GNU General Public License as published by
      8  * the Free Software Foundation; version 2 of the License (not later!)
      9  *
     10  * This program is distributed in the hope that it will be useful,
     11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
     12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
     13  * GNU General Public License for more details.
     14  *
     15  * You should have received a copy of the GNU General Public License
     16  * along with this program; if not, write to the Free Software
     17  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
     18  *
     19  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
     20  */
     21 #include "util.h"
     22 #include <dirent.h>
     23 #include <mntent.h>
     24 #include <stdio.h>
     25 #include <stdlib.h>
     26 #include <string.h>
     27 #include <stdarg.h>
     28 #include <sys/types.h>
     29 #include <sys/stat.h>
     30 #include <sys/wait.h>
     31 #include <pthread.h>
     32 #include <fcntl.h>
     33 #include <unistd.h>
     34 #include <errno.h>
     35 #include <stdbool.h>
     36 #include <linux/list.h>
     37 #include <linux/kernel.h>
     38 
     39 #include "../perf.h"
     40 #include "trace-event.h"
     41 #include <lk/debugfs.h>
     42 #include "evsel.h"
     43 
     44 #define VERSION "0.5"
     45 
     46 static int output_fd;
     47 
     48 
     49 int bigendian(void)
     50 {
     51 	unsigned char str[] = { 0x1, 0x2, 0x3, 0x4, 0x0, 0x0, 0x0, 0x0};
     52 	unsigned int *ptr;
     53 
     54 	ptr = (unsigned int *)(void *)str;
     55 	return *ptr == 0x01020304;
     56 }
     57 
     58 /* unfortunately, you can not stat debugfs or proc files for size */
     59 static int record_file(const char *file, ssize_t hdr_sz)
     60 {
     61 	unsigned long long size = 0;
     62 	char buf[BUFSIZ], *sizep;
     63 	off_t hdr_pos = lseek(output_fd, 0, SEEK_CUR);
     64 	int r, fd;
     65 	int err = -EIO;
     66 
     67 	fd = open(file, O_RDONLY);
     68 	if (fd < 0) {
     69 		pr_debug("Can't read '%s'", file);
     70 		return -errno;
     71 	}
     72 
     73 	/* put in zeros for file size, then fill true size later */
     74 	if (hdr_sz) {
     75 		if (write(output_fd, &size, hdr_sz) != hdr_sz)
     76 			goto out;
     77 	}
     78 
     79 	do {
     80 		r = read(fd, buf, BUFSIZ);
     81 		if (r > 0) {
     82 			size += r;
     83 			if (write(output_fd, buf, r) != r)
     84 				goto out;
     85 		}
     86 	} while (r > 0);
     87 
     88 	/* ugh, handle big-endian hdr_size == 4 */
     89 	sizep = (char*)&size;
     90 	if (bigendian())
     91 		sizep += sizeof(u64) - hdr_sz;
     92 
     93 	if (hdr_sz && pwrite(output_fd, sizep, hdr_sz, hdr_pos) < 0) {
     94 		pr_debug("writing file size failed\n");
     95 		goto out;
     96 	}
     97 
     98 	err = 0;
     99 out:
    100 	close(fd);
    101 	return err;
    102 }
    103 
    104 static int record_header_files(void)
    105 {
    106 	char *path;
    107 	struct stat st;
    108 	int err = -EIO;
    109 
    110 	path = get_tracing_file("events/header_page");
    111 	if (!path) {
    112 		pr_debug("can't get tracing/events/header_page");
    113 		return -ENOMEM;
    114 	}
    115 
    116 	if (stat(path, &st) < 0) {
    117 		pr_debug("can't read '%s'", path);
    118 		goto out;
    119 	}
    120 
    121 	if (write(output_fd, "header_page", 12) != 12) {
    122 		pr_debug("can't write header_page\n");
    123 		goto out;
    124 	}
    125 
    126 	if (record_file(path, 8) < 0) {
    127 		pr_debug("can't record header_page file\n");
    128 		goto out;
    129 	}
    130 
    131 	put_tracing_file(path);
    132 
    133 	path = get_tracing_file("events/header_event");
    134 	if (!path) {
    135 		pr_debug("can't get tracing/events/header_event");
    136 		err = -ENOMEM;
    137 		goto out;
    138 	}
    139 
    140 	if (stat(path, &st) < 0) {
    141 		pr_debug("can't read '%s'", path);
    142 		goto out;
    143 	}
    144 
    145 	if (write(output_fd, "header_event", 13) != 13) {
    146 		pr_debug("can't write header_event\n");
    147 		goto out;
    148 	}
    149 
    150 	if (record_file(path, 8) < 0) {
    151 		pr_debug("can't record header_event file\n");
    152 		goto out;
    153 	}
    154 
    155 	err = 0;
    156 out:
    157 	put_tracing_file(path);
    158 	return err;
    159 }
    160 
    161 static bool name_in_tp_list(char *sys, struct tracepoint_path *tps)
    162 {
    163 	while (tps) {
    164 		if (!strcmp(sys, tps->name))
    165 			return true;
    166 		tps = tps->next;
    167 	}
    168 
    169 	return false;
    170 }
    171 
    172 static int copy_event_system(const char *sys, struct tracepoint_path *tps)
    173 {
    174 	struct dirent *dent;
    175 	struct stat st;
    176 	char *format;
    177 	DIR *dir;
    178 	int count = 0;
    179 	int ret;
    180 	int err;
    181 
    182 	dir = opendir(sys);
    183 	if (!dir) {
    184 		pr_debug("can't read directory '%s'", sys);
    185 		return -errno;
    186 	}
    187 
    188 	while ((dent = readdir(dir))) {
    189 		if (dent->d_type != DT_DIR ||
    190 		    strcmp(dent->d_name, ".") == 0 ||
    191 		    strcmp(dent->d_name, "..") == 0 ||
    192 		    !name_in_tp_list(dent->d_name, tps))
    193 			continue;
    194 		format = malloc(strlen(sys) + strlen(dent->d_name) + 10);
    195 		if (!format) {
    196 			err = -ENOMEM;
    197 			goto out;
    198 		}
    199 		sprintf(format, "%s/%s/format", sys, dent->d_name);
    200 		ret = stat(format, &st);
    201 		free(format);
    202 		if (ret < 0)
    203 			continue;
    204 		count++;
    205 	}
    206 
    207 	if (write(output_fd, &count, 4) != 4) {
    208 		err = -EIO;
    209 		pr_debug("can't write count\n");
    210 		goto out;
    211 	}
    212 
    213 	rewinddir(dir);
    214 	while ((dent = readdir(dir))) {
    215 		if (dent->d_type != DT_DIR ||
    216 		    strcmp(dent->d_name, ".") == 0 ||
    217 		    strcmp(dent->d_name, "..") == 0 ||
    218 		    !name_in_tp_list(dent->d_name, tps))
    219 			continue;
    220 		format = malloc(strlen(sys) + strlen(dent->d_name) + 10);
    221 		if (!format) {
    222 			err = -ENOMEM;
    223 			goto out;
    224 		}
    225 		sprintf(format, "%s/%s/format", sys, dent->d_name);
    226 		ret = stat(format, &st);
    227 
    228 		if (ret >= 0) {
    229 			err = record_file(format, 8);
    230 			if (err) {
    231 				free(format);
    232 				goto out;
    233 			}
    234 		}
    235 		free(format);
    236 	}
    237 	err = 0;
    238 out:
    239 	closedir(dir);
    240 	return err;
    241 }
    242 
    243 static int record_ftrace_files(struct tracepoint_path *tps)
    244 {
    245 	char *path;
    246 	int ret;
    247 
    248 	path = get_tracing_file("events/ftrace");
    249 	if (!path) {
    250 		pr_debug("can't get tracing/events/ftrace");
    251 		return -ENOMEM;
    252 	}
    253 
    254 	ret = copy_event_system(path, tps);
    255 
    256 	put_tracing_file(path);
    257 
    258 	return ret;
    259 }
    260 
    261 static bool system_in_tp_list(char *sys, struct tracepoint_path *tps)
    262 {
    263 	while (tps) {
    264 		if (!strcmp(sys, tps->system))
    265 			return true;
    266 		tps = tps->next;
    267 	}
    268 
    269 	return false;
    270 }
    271 
    272 static int record_event_files(struct tracepoint_path *tps)
    273 {
    274 	struct dirent *dent;
    275 	struct stat st;
    276 	char *path;
    277 	char *sys;
    278 	DIR *dir;
    279 	int count = 0;
    280 	int ret;
    281 	int err;
    282 
    283 	path = get_tracing_file("events");
    284 	if (!path) {
    285 		pr_debug("can't get tracing/events");
    286 		return -ENOMEM;
    287 	}
    288 
    289 	dir = opendir(path);
    290 	if (!dir) {
    291 		err = -errno;
    292 		pr_debug("can't read directory '%s'", path);
    293 		goto out;
    294 	}
    295 
    296 	while ((dent = readdir(dir))) {
    297 		if (dent->d_type != DT_DIR ||
    298 		    strcmp(dent->d_name, ".") == 0 ||
    299 		    strcmp(dent->d_name, "..") == 0 ||
    300 		    strcmp(dent->d_name, "ftrace") == 0 ||
    301 		    !system_in_tp_list(dent->d_name, tps))
    302 			continue;
    303 		count++;
    304 	}
    305 
    306 	if (write(output_fd, &count, 4) != 4) {
    307 		err = -EIO;
    308 		pr_debug("can't write count\n");
    309 		goto out;
    310 	}
    311 
    312 	rewinddir(dir);
    313 	while ((dent = readdir(dir))) {
    314 		if (dent->d_type != DT_DIR ||
    315 		    strcmp(dent->d_name, ".") == 0 ||
    316 		    strcmp(dent->d_name, "..") == 0 ||
    317 		    strcmp(dent->d_name, "ftrace") == 0 ||
    318 		    !system_in_tp_list(dent->d_name, tps))
    319 			continue;
    320 		sys = malloc(strlen(path) + strlen(dent->d_name) + 2);
    321 		if (!sys) {
    322 			err = -ENOMEM;
    323 			goto out;
    324 		}
    325 		sprintf(sys, "%s/%s", path, dent->d_name);
    326 		ret = stat(sys, &st);
    327 		if (ret >= 0) {
    328 			ssize_t size = strlen(dent->d_name) + 1;
    329 
    330 			if (write(output_fd, dent->d_name, size) != size ||
    331 			    copy_event_system(sys, tps) < 0) {
    332 				err = -EIO;
    333 				free(sys);
    334 				goto out;
    335 			}
    336 		}
    337 		free(sys);
    338 	}
    339 	err = 0;
    340 out:
    341 	closedir(dir);
    342 	put_tracing_file(path);
    343 
    344 	return err;
    345 }
    346 
    347 static int record_proc_kallsyms(void)
    348 {
    349 	unsigned int size;
    350 	const char *path = "/proc/kallsyms";
    351 	struct stat st;
    352 	int ret, err = 0;
    353 
    354 	ret = stat(path, &st);
    355 	if (ret < 0) {
    356 		/* not found */
    357 		size = 0;
    358 		if (write(output_fd, &size, 4) != 4)
    359 			err = -EIO;
    360 		return err;
    361 	}
    362 	return record_file(path, 4);
    363 }
    364 
    365 static int record_ftrace_printk(void)
    366 {
    367 	unsigned int size;
    368 	char *path;
    369 	struct stat st;
    370 	int ret, err = 0;
    371 
    372 	path = get_tracing_file("printk_formats");
    373 	if (!path) {
    374 		pr_debug("can't get tracing/printk_formats");
    375 		return -ENOMEM;
    376 	}
    377 
    378 	ret = stat(path, &st);
    379 	if (ret < 0) {
    380 		/* not found */
    381 		size = 0;
    382 		if (write(output_fd, &size, 4) != 4)
    383 			err = -EIO;
    384 		goto out;
    385 	}
    386 	err = record_file(path, 4);
    387 
    388 out:
    389 	put_tracing_file(path);
    390 	return err;
    391 }
    392 
    393 static void
    394 put_tracepoints_path(struct tracepoint_path *tps)
    395 {
    396 	while (tps) {
    397 		struct tracepoint_path *t = tps;
    398 
    399 		tps = tps->next;
    400 		free(t->name);
    401 		free(t->system);
    402 		free(t);
    403 	}
    404 }
    405 
    406 static struct tracepoint_path *
    407 get_tracepoints_path(struct list_head *pattrs)
    408 {
    409 	struct tracepoint_path path, *ppath = &path;
    410 	struct perf_evsel *pos;
    411 	int nr_tracepoints = 0;
    412 
    413 	list_for_each_entry(pos, pattrs, node) {
    414 		if (pos->attr.type != PERF_TYPE_TRACEPOINT)
    415 			continue;
    416 		++nr_tracepoints;
    417 
    418 		if (pos->name) {
    419 			ppath->next = tracepoint_name_to_path(pos->name);
    420 			if (ppath->next)
    421 				goto next;
    422 
    423 			if (strchr(pos->name, ':') == NULL)
    424 				goto try_id;
    425 
    426 			goto error;
    427 		}
    428 
    429 try_id:
    430 		ppath->next = tracepoint_id_to_path(pos->attr.config);
    431 		if (!ppath->next) {
    432 error:
    433 			pr_debug("No memory to alloc tracepoints list\n");
    434 			put_tracepoints_path(&path);
    435 			return NULL;
    436 		}
    437 next:
    438 		ppath = ppath->next;
    439 	}
    440 
    441 	return nr_tracepoints > 0 ? path.next : NULL;
    442 }
    443 
    444 bool have_tracepoints(struct list_head *pattrs)
    445 {
    446 	struct perf_evsel *pos;
    447 
    448 	list_for_each_entry(pos, pattrs, node)
    449 		if (pos->attr.type == PERF_TYPE_TRACEPOINT)
    450 			return true;
    451 
    452 	return false;
    453 }
    454 
    455 static int tracing_data_header(void)
    456 {
    457 	char buf[20];
    458 	ssize_t size;
    459 
    460 	/* just guessing this is someone's birthday.. ;) */
    461 	buf[0] = 23;
    462 	buf[1] = 8;
    463 	buf[2] = 68;
    464 	memcpy(buf + 3, "tracing", 7);
    465 
    466 	if (write(output_fd, buf, 10) != 10)
    467 		return -1;
    468 
    469 	size = strlen(VERSION) + 1;
    470 	if (write(output_fd, VERSION, size) != size)
    471 		return -1;
    472 
    473 	/* save endian */
    474 	if (bigendian())
    475 		buf[0] = 1;
    476 	else
    477 		buf[0] = 0;
    478 
    479 	if (write(output_fd, buf, 1) != 1)
    480 		return -1;
    481 
    482 	/* save size of long */
    483 	buf[0] = sizeof(long);
    484 	if (write(output_fd, buf, 1) != 1)
    485 		return -1;
    486 
    487 	/* save page_size */
    488 	if (write(output_fd, &page_size, 4) != 4)
    489 		return -1;
    490 
    491 	return 0;
    492 }
    493 
    494 struct tracing_data *tracing_data_get(struct list_head *pattrs,
    495 				      int fd, bool temp)
    496 {
    497 	struct tracepoint_path *tps;
    498 	struct tracing_data *tdata;
    499 	int err;
    500 
    501 	output_fd = fd;
    502 
    503 	tps = get_tracepoints_path(pattrs);
    504 	if (!tps)
    505 		return NULL;
    506 
    507 	tdata = malloc(sizeof(*tdata));
    508 	if (!tdata)
    509 		return NULL;
    510 
    511 	tdata->temp = temp;
    512 	tdata->size = 0;
    513 
    514 	if (temp) {
    515 		int temp_fd;
    516 
    517 		snprintf(tdata->temp_file, sizeof(tdata->temp_file),
    518 			 "/tmp/perf-XXXXXX");
    519 		if (!mkstemp(tdata->temp_file)) {
    520 			pr_debug("Can't make temp file");
    521 			return NULL;
    522 		}
    523 
    524 		temp_fd = open(tdata->temp_file, O_RDWR);
    525 		if (temp_fd < 0) {
    526 			pr_debug("Can't read '%s'", tdata->temp_file);
    527 			return NULL;
    528 		}
    529 
    530 		/*
    531 		 * Set the temp file the default output, so all the
    532 		 * tracing data are stored into it.
    533 		 */
    534 		output_fd = temp_fd;
    535 	}
    536 
    537 	err = tracing_data_header();
    538 	if (err)
    539 		goto out;
    540 	err = record_header_files();
    541 	if (err)
    542 		goto out;
    543 	err = record_ftrace_files(tps);
    544 	if (err)
    545 		goto out;
    546 	err = record_event_files(tps);
    547 	if (err)
    548 		goto out;
    549 	err = record_proc_kallsyms();
    550 	if (err)
    551 		goto out;
    552 	err = record_ftrace_printk();
    553 
    554 out:
    555 	/*
    556 	 * All tracing data are stored by now, we can restore
    557 	 * the default output file in case we used temp file.
    558 	 */
    559 	if (temp) {
    560 		tdata->size = lseek(output_fd, 0, SEEK_CUR);
    561 		close(output_fd);
    562 		output_fd = fd;
    563 	}
    564 
    565 	if (err) {
    566 		free(tdata);
    567 		tdata = NULL;
    568 	}
    569 
    570 	put_tracepoints_path(tps);
    571 	return tdata;
    572 }
    573 
    574 int tracing_data_put(struct tracing_data *tdata)
    575 {
    576 	int err = 0;
    577 
    578 	if (tdata->temp) {
    579 		err = record_file(tdata->temp_file, 0);
    580 		unlink(tdata->temp_file);
    581 	}
    582 
    583 	free(tdata);
    584 	return err;
    585 }
    586 
    587 int read_tracing_data(int fd, struct list_head *pattrs)
    588 {
    589 	int err;
    590 	struct tracing_data *tdata;
    591 
    592 	/*
    593 	 * We work over the real file, so we can write data
    594 	 * directly, no temp file is needed.
    595 	 */
    596 	tdata = tracing_data_get(pattrs, fd, false);
    597 	if (!tdata)
    598 		return -ENOMEM;
    599 
    600 	err = tracing_data_put(tdata);
    601 	return err;
    602 }
    603