1 /* vi: set sw=4 ts=4: */
2 /*
3  * Utility routines.
4  *
5  * Copyright 1998 by Albert Cahalan; all rights reserved.
6  * Copyright (C) 2002 by Vladimir Oleynik <dzo@simtreas.ru>
7  * SELinux support: (c) 2007 by Yuichi Nakamura <ynakam@hitachisoft.jp>
8  *
9  * Licensed under GPLv2 or later, see file LICENSE in this source tree.
10  */
11 
12 #include "libbb.h"
13 
14 
15 typedef struct id_to_name_map_t {
16 	uid_t id;
17 	char name[USERNAME_MAX_SIZE];
18 } id_to_name_map_t;
19 
20 typedef struct cache_t {
21 	id_to_name_map_t *cache;
22 	int size;
23 } cache_t;
24 
25 static cache_t username, groupname;
26 
clear_cache(cache_t * cp)27 static void clear_cache(cache_t *cp)
28 {
29 	free(cp->cache);
30 	cp->cache = NULL;
31 	cp->size = 0;
32 }
clear_username_cache(void)33 void FAST_FUNC clear_username_cache(void)
34 {
35 	clear_cache(&username);
36 	clear_cache(&groupname);
37 }
38 
39 #if 0 /* more generic, but we don't need that yet */
40 /* Returns -N-1 if not found. */
41 /* cp->cache[N] is allocated and must be filled in this case */
42 static int get_cached(cache_t *cp, uid_t id)
43 {
44 	int i;
45 	for (i = 0; i < cp->size; i++)
46 		if (cp->cache[i].id == id)
47 			return i;
48 	i = cp->size++;
49 	cp->cache = xrealloc_vector(cp->cache, 2, i);
50 	cp->cache[i++].id = id;
51 	return -i;
52 }
53 #endif
54 
get_cached(cache_t * cp,uid_t id,char * FAST_FUNC x2x_utoa (uid_t id))55 static char* get_cached(cache_t *cp, uid_t id,
56 			char* FAST_FUNC x2x_utoa(uid_t id))
57 {
58 	int i;
59 	for (i = 0; i < cp->size; i++)
60 		if (cp->cache[i].id == id)
61 			return cp->cache[i].name;
62 	i = cp->size++;
63 	cp->cache = xrealloc_vector(cp->cache, 2, i);
64 	cp->cache[i].id = id;
65 	/* Never fails. Generates numeric string if name isn't found */
66 	safe_strncpy(cp->cache[i].name, x2x_utoa(id), sizeof(cp->cache[i].name));
67 	return cp->cache[i].name;
68 }
get_cached_username(uid_t uid)69 const char* FAST_FUNC get_cached_username(uid_t uid)
70 {
71 	return get_cached(&username, uid, uid2uname_utoa);
72 }
get_cached_groupname(gid_t gid)73 const char* FAST_FUNC get_cached_groupname(gid_t gid)
74 {
75 	return get_cached(&groupname, gid, gid2group_utoa);
76 }
77 
78 
79 #define PROCPS_BUFSIZE 1024
80 
read_to_buf(const char * filename,void * buf)81 static int read_to_buf(const char *filename, void *buf)
82 {
83 	int fd;
84 	/* open_read_close() would do two reads, checking for EOF.
85 	 * When you have 10000 /proc/$NUM/stat to read, it isn't desirable */
86 	ssize_t ret = -1;
87 	fd = open(filename, O_RDONLY);
88 	if (fd >= 0) {
89 		ret = read(fd, buf, PROCPS_BUFSIZE-1);
90 		close(fd);
91 	}
92 	((char *)buf)[ret > 0 ? ret : 0] = '\0';
93 	return ret;
94 }
95 
alloc_procps_scan(void)96 static procps_status_t* FAST_FUNC alloc_procps_scan(void)
97 {
98 	unsigned n = getpagesize();
99 	procps_status_t* sp = xzalloc(sizeof(procps_status_t));
100 	sp->dir = xopendir("/proc");
101 	while (1) {
102 		n >>= 1;
103 		if (!n) break;
104 		sp->shift_pages_to_bytes++;
105 	}
106 	sp->shift_pages_to_kb = sp->shift_pages_to_bytes - 10;
107 	return sp;
108 }
109 
free_procps_scan(procps_status_t * sp)110 void FAST_FUNC free_procps_scan(procps_status_t* sp)
111 {
112 	closedir(sp->dir);
113 #if ENABLE_FEATURE_SHOW_THREADS
114 	if (sp->task_dir)
115 		closedir(sp->task_dir);
116 #endif
117 	free(sp->argv0);
118 	free(sp->exe);
119 	IF_SELINUX(free(sp->context);)
120 	free(sp);
121 }
122 
123 #if ENABLE_FEATURE_TOPMEM || ENABLE_PMAP
fast_strtoul_16(char ** endptr)124 static unsigned long fast_strtoul_16(char **endptr)
125 {
126 	unsigned char c;
127 	char *str = *endptr;
128 	unsigned long n = 0;
129 
130 	/* Need to stop on both ' ' and '\n' */
131 	while ((c = *str++) > ' ') {
132 		c = ((c|0x20) - '0');
133 		if (c > 9)
134 			/* c = c + '0' - 'a' + 10: */
135 			c = c - ('a' - '0' - 10);
136 		n = n*16 + c;
137 	}
138 	*endptr = str; /* We skip trailing space! */
139 	return n;
140 }
141 #endif
142 
143 #if ENABLE_FEATURE_FAST_TOP || ENABLE_FEATURE_TOPMEM || ENABLE_PMAP
144 /* We cut a lot of corners here for speed */
fast_strtoul_10(char ** endptr)145 static unsigned long fast_strtoul_10(char **endptr)
146 {
147 	unsigned char c;
148 	char *str = *endptr;
149 	unsigned long n = *str - '0';
150 
151 	/* Need to stop on both ' ' and '\n' */
152 	while ((c = *++str) > ' ')
153 		n = n*10 + (c - '0');
154 
155 	*endptr = str + 1; /* We skip trailing space! */
156 	return n;
157 }
158 
159 # if ENABLE_FEATURE_FAST_TOP
fast_strtol_10(char ** endptr)160 static long fast_strtol_10(char **endptr)
161 {
162 	if (**endptr != '-')
163 		return fast_strtoul_10(endptr);
164 
165 	(*endptr)++;
166 	return - (long)fast_strtoul_10(endptr);
167 }
168 # endif
169 
skip_fields(char * str,int count)170 static char *skip_fields(char *str, int count)
171 {
172 	do {
173 		while (*str++ != ' ')
174 			continue;
175 		/* we found a space char, str points after it */
176 	} while (--count);
177 	return str;
178 }
179 #endif
180 
181 #if ENABLE_FEATURE_TOPMEM || ENABLE_PMAP
procps_read_smaps(pid_t pid,struct smaprec * total,void (* cb)(struct smaprec *,void *),void * data)182 int FAST_FUNC procps_read_smaps(pid_t pid, struct smaprec *total,
183 		void (*cb)(struct smaprec *, void *), void *data)
184 {
185 	FILE *file;
186 	struct smaprec currec;
187 	char filename[sizeof("/proc/%u/smaps") + sizeof(int)*3];
188 	char buf[PROCPS_BUFSIZE];
189 #if !ENABLE_PMAP
190 	void (*cb)(struct smaprec *, void *) = NULL;
191 	void *data = NULL;
192 #endif
193 
194 	sprintf(filename, "/proc/%u/smaps", (int)pid);
195 
196 	file = fopen_for_read(filename);
197 	if (!file)
198 		return 1;
199 
200 	memset(&currec, 0, sizeof(currec));
201 	while (fgets(buf, PROCPS_BUFSIZE, file)) {
202 		// Each mapping datum has this form:
203 		// f7d29000-f7d39000 rw-s FILEOFS M:m INODE FILENAME
204 		// Size:                nnn kB
205 		// Rss:                 nnn kB
206 		// .....
207 
208 		char *tp, *p;
209 
210 #define SCAN(S, X) \
211 		if ((tp = is_prefixed_with(buf, S)) != NULL) {       \
212 			tp = skip_whitespace(tp);                    \
213 			total->X += currec.X = fast_strtoul_10(&tp); \
214 			continue;                                    \
215 		}
216 		if (cb) {
217 			SCAN("Pss:"  , smap_pss     );
218 			SCAN("Swap:" , smap_swap    );
219 		}
220 		SCAN("Private_Dirty:", private_dirty);
221 		SCAN("Private_Clean:", private_clean);
222 		SCAN("Shared_Dirty:" , shared_dirty );
223 		SCAN("Shared_Clean:" , shared_clean );
224 #undef SCAN
225 		tp = strchr(buf, '-');
226 		if (tp) {
227 			// We reached next mapping - the line of this form:
228 			// f7d29000-f7d39000 rw-s FILEOFS M:m INODE FILENAME
229 
230 			if (cb) {
231 				/* If we have a previous record, there's nothing more
232 				 * for it, call the callback and clear currec
233 				 */
234 				if (currec.smap_size)
235 					cb(&currec, data);
236 				free(currec.smap_name);
237 			}
238 			memset(&currec, 0, sizeof(currec));
239 
240 			*tp = ' ';
241 			tp = buf;
242 			currec.smap_start = fast_strtoul_16(&tp);
243 			currec.smap_size = (fast_strtoul_16(&tp) - currec.smap_start) >> 10;
244 
245 			strncpy(currec.smap_mode, tp, sizeof(currec.smap_mode)-1);
246 
247 			// skipping "rw-s FILEOFS M:m INODE "
248 			tp = skip_whitespace(skip_fields(tp, 4));
249 			// filter out /dev/something (something != zero)
250 			if (!is_prefixed_with(tp, "/dev/") || strcmp(tp, "/dev/zero\n") == 0) {
251 				if (currec.smap_mode[1] == 'w') {
252 					currec.mapped_rw = currec.smap_size;
253 					total->mapped_rw += currec.smap_size;
254 				} else if (currec.smap_mode[1] == '-') {
255 					currec.mapped_ro = currec.smap_size;
256 					total->mapped_ro += currec.smap_size;
257 				}
258 			}
259 
260 			if (strcmp(tp, "[stack]\n") == 0)
261 				total->stack += currec.smap_size;
262 			if (cb) {
263 				p = skip_non_whitespace(tp);
264 				if (p == tp) {
265 					currec.smap_name = xstrdup("  [ anon ]");
266 				} else {
267 					*p = '\0';
268 					currec.smap_name = xstrdup(tp);
269 				}
270 			}
271 			total->smap_size += currec.smap_size;
272 		}
273 	}
274 	fclose(file);
275 
276 	if (cb) {
277 		if (currec.smap_size)
278 			cb(&currec, data);
279 		free(currec.smap_name);
280 	}
281 
282 	return 0;
283 }
284 #endif
285 
procps_scan(procps_status_t * sp,int flags)286 procps_status_t* FAST_FUNC procps_scan(procps_status_t* sp, int flags)
287 {
288 	if (!sp)
289 		sp = alloc_procps_scan();
290 
291 	for (;;) {
292 		struct dirent *entry;
293 		char buf[PROCPS_BUFSIZE];
294 		long tasknice;
295 		unsigned pid;
296 		int n;
297 		char filename[sizeof("/proc/%u/task/%u/cmdline") + sizeof(int)*3 * 2];
298 		char *filename_tail;
299 
300 #if ENABLE_FEATURE_SHOW_THREADS
301 		if (sp->task_dir) {
302 			entry = readdir(sp->task_dir);
303 			if (entry)
304 				goto got_entry;
305 			closedir(sp->task_dir);
306 			sp->task_dir = NULL;
307 		}
308 #endif
309 		entry = readdir(sp->dir);
310 		if (entry == NULL) {
311 			free_procps_scan(sp);
312 			return NULL;
313 		}
314  IF_FEATURE_SHOW_THREADS(got_entry:)
315 		pid = bb_strtou(entry->d_name, NULL, 10);
316 		if (errno)
317 			continue;
318 #if ENABLE_FEATURE_SHOW_THREADS
319 		if ((flags & PSSCAN_TASKS) && !sp->task_dir) {
320 			/* We found another /proc/PID. Do not use it,
321 			 * there will be /proc/PID/task/PID (same PID!),
322 			 * so just go ahead and dive into /proc/PID/task. */
323 			sprintf(filename, "/proc/%u/task", pid);
324 			/* Note: if opendir fails, we just go to next /proc/XXX */
325 			sp->task_dir = opendir(filename);
326 			sp->main_thread_pid = pid;
327 			continue;
328 		}
329 #endif
330 
331 		/* After this point we can:
332 		 * "break": stop parsing, return the data
333 		 * "continue": try next /proc/XXX
334 		 */
335 
336 		memset(&sp->vsz, 0, sizeof(*sp) - offsetof(procps_status_t, vsz));
337 
338 		sp->pid = pid;
339 		if (!(flags & ~PSSCAN_PID))
340 			break; /* we needed only pid, we got it */
341 
342 #if ENABLE_SELINUX
343 		if (flags & PSSCAN_CONTEXT) {
344 			if (getpidcon(sp->pid, &sp->context) < 0)
345 				sp->context = NULL;
346 		}
347 #endif
348 
349 #if ENABLE_FEATURE_SHOW_THREADS
350 		if (sp->task_dir)
351 			filename_tail = filename + sprintf(filename, "/proc/%u/task/%u/", sp->main_thread_pid, pid);
352 		else
353 #endif
354 			filename_tail = filename + sprintf(filename, "/proc/%u/", pid);
355 
356 		if (flags & PSSCAN_UIDGID) {
357 			struct stat sb;
358 			if (stat(filename, &sb))
359 				continue; /* process probably exited */
360 			/* Effective UID/GID, not real */
361 			sp->uid = sb.st_uid;
362 			sp->gid = sb.st_gid;
363 		}
364 
365 		/* These are all retrieved from proc/NN/stat in one go: */
366 		if (flags & (PSSCAN_PPID | PSSCAN_PGID | PSSCAN_SID
367 			| PSSCAN_COMM | PSSCAN_STATE
368 			| PSSCAN_VSZ | PSSCAN_RSS
369 			| PSSCAN_STIME | PSSCAN_UTIME | PSSCAN_START_TIME
370 			| PSSCAN_TTY | PSSCAN_NICE
371 			| PSSCAN_CPU)
372 		) {
373 			char *cp, *comm1;
374 			int tty;
375 #if !ENABLE_FEATURE_FAST_TOP
376 			unsigned long vsz, rss;
377 #endif
378 			/* see proc(5) for some details on this */
379 			strcpy(filename_tail, "stat");
380 			n = read_to_buf(filename, buf);
381 			if (n < 0)
382 				continue; /* process probably exited */
383 			cp = strrchr(buf, ')'); /* split into "PID (cmd" and "<rest>" */
384 			/*if (!cp || cp[1] != ' ')
385 				continue;*/
386 			cp[0] = '\0';
387 			BUILD_BUG_ON(sizeof(sp->comm) < 16);
388 			comm1 = strchr(buf, '(');
389 			/*if (comm1)*/
390 				safe_strncpy(sp->comm, comm1 + 1, sizeof(sp->comm));
391 
392 #if !ENABLE_FEATURE_FAST_TOP
393 			n = sscanf(cp+2,
394 				"%c %u "               /* state, ppid */
395 				"%u %u %d %*s "        /* pgid, sid, tty, tpgid */
396 				"%*s %*s %*s %*s %*s " /* flags, min_flt, cmin_flt, maj_flt, cmaj_flt */
397 				"%lu %lu "             /* utime, stime */
398 				"%*s %*s %*s "         /* cutime, cstime, priority */
399 				"%ld "                 /* nice */
400 				"%*s %*s "             /* timeout, it_real_value */
401 				"%lu "                 /* start_time */
402 				"%lu "                 /* vsize */
403 				"%lu "                 /* rss */
404 # if ENABLE_FEATURE_TOP_SMP_PROCESS
405 				"%*s %*s %*s %*s %*s %*s " /*rss_rlim, start_code, end_code, start_stack, kstk_esp, kstk_eip */
406 				"%*s %*s %*s %*s "         /*signal, blocked, sigignore, sigcatch */
407 				"%*s %*s %*s %*s "         /*wchan, nswap, cnswap, exit_signal */
408 				"%d"                       /*cpu last seen on*/
409 # endif
410 				,
411 				sp->state, &sp->ppid,
412 				&sp->pgid, &sp->sid, &tty,
413 				&sp->utime, &sp->stime,
414 				&tasknice,
415 				&sp->start_time,
416 				&vsz,
417 				&rss
418 # if ENABLE_FEATURE_TOP_SMP_PROCESS
419 				, &sp->last_seen_on_cpu
420 # endif
421 				);
422 
423 			if (n < 11)
424 				continue; /* bogus data, get next /proc/XXX */
425 # if ENABLE_FEATURE_TOP_SMP_PROCESS
426 			if (n == 11)
427 				sp->last_seen_on_cpu = 0;
428 # endif
429 
430 			/* vsz is in bytes and we want kb */
431 			sp->vsz = vsz >> 10;
432 			/* vsz is in bytes but rss is in *PAGES*! Can you believe that? */
433 			sp->rss = rss << sp->shift_pages_to_kb;
434 			sp->tty_major = (tty >> 8) & 0xfff;
435 			sp->tty_minor = (tty & 0xff) | ((tty >> 12) & 0xfff00);
436 #else
437 /* This costs ~100 bytes more but makes top faster by 20%
438  * If you run 10000 processes, this may be important for you */
439 			sp->state[0] = cp[2];
440 			cp += 4;
441 			sp->ppid = fast_strtoul_10(&cp);
442 			sp->pgid = fast_strtoul_10(&cp);
443 			sp->sid = fast_strtoul_10(&cp);
444 			tty = fast_strtoul_10(&cp);
445 			sp->tty_major = (tty >> 8) & 0xfff;
446 			sp->tty_minor = (tty & 0xff) | ((tty >> 12) & 0xfff00);
447 			cp = skip_fields(cp, 6); /* tpgid, flags, min_flt, cmin_flt, maj_flt, cmaj_flt */
448 			sp->utime = fast_strtoul_10(&cp);
449 			sp->stime = fast_strtoul_10(&cp);
450 			cp = skip_fields(cp, 3); /* cutime, cstime, priority */
451 			tasknice = fast_strtol_10(&cp);
452 			cp = skip_fields(cp, 2); /* timeout, it_real_value */
453 			sp->start_time = fast_strtoul_10(&cp);
454 			/* vsz is in bytes and we want kb */
455 			sp->vsz = fast_strtoul_10(&cp) >> 10;
456 			/* vsz is in bytes but rss is in *PAGES*! Can you believe that? */
457 			sp->rss = fast_strtoul_10(&cp) << sp->shift_pages_to_kb;
458 # if ENABLE_FEATURE_TOP_SMP_PROCESS
459 			/* (6): rss_rlim, start_code, end_code, start_stack, kstk_esp, kstk_eip */
460 			/* (4): signal, blocked, sigignore, sigcatch */
461 			/* (4): wchan, nswap, cnswap, exit_signal */
462 			cp = skip_fields(cp, 14);
463 //FIXME: is it safe to assume this field exists?
464 			sp->last_seen_on_cpu = fast_strtoul_10(&cp);
465 # endif
466 #endif /* FEATURE_FAST_TOP */
467 
468 #if ENABLE_FEATURE_PS_ADDITIONAL_COLUMNS
469 			sp->niceness = tasknice;
470 #endif
471 
472 			if (sp->vsz == 0 && sp->state[0] != 'Z')
473 				sp->state[1] = 'W';
474 			else
475 				sp->state[1] = ' ';
476 			if (tasknice < 0)
477 				sp->state[2] = '<';
478 			else if (tasknice) /* > 0 */
479 				sp->state[2] = 'N';
480 			else
481 				sp->state[2] = ' ';
482 		}
483 
484 #if ENABLE_FEATURE_TOPMEM
485 		if (flags & PSSCAN_SMAPS)
486 			procps_read_smaps(pid, &sp->smaps, NULL, NULL);
487 #endif /* TOPMEM */
488 #if ENABLE_FEATURE_PS_ADDITIONAL_COLUMNS
489 		if (flags & PSSCAN_RUIDGID) {
490 			FILE *file;
491 
492 			strcpy(filename_tail, "status");
493 			file = fopen_for_read(filename);
494 			if (file) {
495 				while (fgets(buf, sizeof(buf), file)) {
496 					char *tp;
497 #define SCAN_TWO(str, name, statement) \
498 	if ((tp = is_prefixed_with(buf, str)) != NULL) { \
499 		tp = skip_whitespace(tp); \
500 		sscanf(tp, "%u", &sp->name); \
501 		statement; \
502 	}
503 					SCAN_TWO("Uid:", ruid, continue);
504 					SCAN_TWO("Gid:", rgid, break);
505 #undef SCAN_TWO
506 				}
507 				fclose(file);
508 			}
509 		}
510 #endif /* PS_ADDITIONAL_COLUMNS */
511 		if (flags & PSSCAN_EXE) {
512 			strcpy(filename_tail, "exe");
513 			free(sp->exe);
514 			sp->exe = xmalloc_readlink(filename);
515 		}
516 		/* Note: if /proc/PID/cmdline is empty,
517 		 * code below "breaks". Therefore it must be
518 		 * the last code to parse /proc/PID/xxx data
519 		 * (we used to have /proc/PID/exe parsing after it
520 		 * and were getting stale sp->exe).
521 		 */
522 #if 0 /* PSSCAN_CMD is not used */
523 		if (flags & (PSSCAN_CMD|PSSCAN_ARGV0)) {
524 			free(sp->argv0);
525 			sp->argv0 = NULL;
526 			free(sp->cmd);
527 			sp->cmd = NULL;
528 			strcpy(filename_tail, "cmdline");
529 			/* TODO: to get rid of size limits, read into malloc buf,
530 			 * then realloc it down to real size. */
531 			n = read_to_buf(filename, buf);
532 			if (n <= 0)
533 				break;
534 			if (flags & PSSCAN_ARGV0)
535 				sp->argv0 = xstrdup(buf);
536 			if (flags & PSSCAN_CMD) {
537 				do {
538 					n--;
539 					if ((unsigned char)(buf[n]) < ' ')
540 						buf[n] = ' ';
541 				} while (n);
542 				sp->cmd = xstrdup(buf);
543 			}
544 		}
545 #else
546 		if (flags & (PSSCAN_ARGV0|PSSCAN_ARGVN)) {
547 			free(sp->argv0);
548 			sp->argv0 = NULL;
549 			strcpy(filename_tail, "cmdline");
550 			n = read_to_buf(filename, buf);
551 			if (n <= 0)
552 				break;
553 			if (flags & PSSCAN_ARGVN) {
554 				sp->argv_len = n;
555 				sp->argv0 = xmemdup(buf, n + 1);
556 				/* sp->argv0[n] = '\0'; - buf has it */
557 			} else {
558 				sp->argv_len = 0;
559 				sp->argv0 = xstrdup(buf);
560 			}
561 		}
562 #endif
563 		break;
564 	} /* for (;;) */
565 
566 	return sp;
567 }
568 
read_cmdline(char * buf,int col,unsigned pid,const char * comm)569 void FAST_FUNC read_cmdline(char *buf, int col, unsigned pid, const char *comm)
570 {
571 	int sz;
572 	char filename[sizeof("/proc/%u/cmdline") + sizeof(int)*3];
573 
574 	sprintf(filename, "/proc/%u/cmdline", pid);
575 	sz = open_read_close(filename, buf, col - 1);
576 	if (sz > 0) {
577 		const char *base;
578 		int comm_len;
579 
580 		buf[sz] = '\0';
581 		while (--sz >= 0 && buf[sz] == '\0')
582 			continue;
583 		/* Prevent basename("process foo/bar") = "bar" */
584 		strchrnul(buf, ' ')[0] = '\0';
585 		base = bb_basename(buf); /* before we replace argv0's NUL with space */
586 		while (sz >= 0) {
587 			if ((unsigned char)(buf[sz]) < ' ')
588 				buf[sz] = ' ';
589 			sz--;
590 		}
591 		if (base[0] == '-') /* "-sh" (login shell)? */
592 			base++;
593 
594 		/* If comm differs from argv0, prepend "{comm} ".
595 		 * It allows to see thread names set by prctl(PR_SET_NAME).
596 		 */
597 		if (!comm)
598 			return;
599 		comm_len = strlen(comm);
600 		/* Why compare up to comm_len, not COMM_LEN-1?
601 		 * Well, some processes rewrite argv, and use _spaces_ there
602 		 * while rewriting. (KDE is observed to do it).
603 		 * I prefer to still treat argv0 "process foo bar"
604 		 * as 'equal' to comm "process".
605 		 */
606 		if (strncmp(base, comm, comm_len) != 0) {
607 			comm_len += 3;
608 			if (col > comm_len)
609 				memmove(buf + comm_len, buf, col - comm_len);
610 			snprintf(buf, col, "{%s}", comm);
611 			if (col <= comm_len)
612 				return;
613 			buf[comm_len - 1] = ' ';
614 			buf[col - 1] = '\0';
615 		}
616 	} else {
617 		snprintf(buf, col, "[%s]", comm ? comm : "?");
618 	}
619 }
620 
621 /* from kernel:
622 	//             pid comm S ppid pgid sid tty_nr tty_pgrp flg
623 	sprintf(buffer,"%d (%s) %c %d  %d   %d  %d     %d       %lu %lu \
624 %lu %lu %lu %lu %lu %ld %ld %ld %ld %d 0 %llu %lu %ld %lu %lu %lu %lu %lu \
625 %lu %lu %lu %lu %lu %lu %lu %lu %d %d %lu %lu %llu\n",
626 		task->pid,
627 		tcomm,
628 		state,
629 		ppid,
630 		pgid,
631 		sid,
632 		tty_nr,
633 		tty_pgrp,
634 		task->flags,
635 		min_flt,
636 		cmin_flt,
637 		maj_flt,
638 		cmaj_flt,
639 		cputime_to_clock_t(utime),
640 		cputime_to_clock_t(stime),
641 		cputime_to_clock_t(cutime),
642 		cputime_to_clock_t(cstime),
643 		priority,
644 		nice,
645 		num_threads,
646 		// 0,
647 		start_time,
648 		vsize,
649 		mm ? get_mm_rss(mm) : 0,
650 		rsslim,
651 		mm ? mm->start_code : 0,
652 		mm ? mm->end_code : 0,
653 		mm ? mm->start_stack : 0,
654 		esp,
655 		eip,
656 the rest is some obsolete cruft
657 */
658