busybox/libbb/procps.c
Denis Vlasenko 98ebab8b76 top,ps: improve /proc/PID/cmdinfo reading code
function                                             old     new   delta
display_status                                         -    1231   +1231
read_cmdline                                           -     101    +101
parse_conf                                          1284    1303     +19
arith                                               2033    2042      +9
collect_blk                                          467     474      +7
fsck_main                                           1909    1911      +2
dhcprelay_main                                      1125    1122      -3
singlemount                                         4555    4547      -8
read_close                                            50      36     -14
get_lcm                                              123     105     -18
ed_main                                             3111    3084     -27
func_args                                             73      28     -45
procps_scan                                          732     658     -74
top_main                                            2187     899   -1288
------------------------------------------------------------------------------
(add/remove: 2/0 grow/shrink: 4/8 up/down: 1369/-1477)       Total: -108 bytes
   text    data     bss     dec     hex filename
 676048    2744   13968  692760   a9218 busybox_old
 675940    2744   13968  692652   a91ac busybox_unstripped
2007-06-30 14:47:41 +00:00

369 lines
8.7 KiB
C

/* vi: set sw=4 ts=4: */
/*
* Utility routines.
*
* Copyright 1998 by Albert Cahalan; all rights reserved.
* Copyright (C) 2002 by Vladimir Oleynik <dzo@simtreas.ru>
* SELinux support: (c) 2007 by Yuichi Nakamura <ynakam@hitachisoft.jp>
*
* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
*/
#include "libbb.h"
typedef struct unsigned_to_name_map_t {
unsigned id;
char name[USERNAME_MAX_SIZE];
} unsigned_to_name_map_t;
typedef struct cache_t {
unsigned_to_name_map_t *cache;
int size;
} cache_t;
static cache_t username, groupname;
static void clear_cache(cache_t *cp)
{
free(cp->cache);
cp->cache = NULL;
cp->size = 0;
}
void clear_username_cache(void)
{
clear_cache(&username);
clear_cache(&groupname);
}
#if 0 /* more generic, but we don't need that yet */
/* Returns -N-1 if not found. */
/* cp->cache[N] is allocated and must be filled in this case */
static int get_cached(cache_t *cp, unsigned id)
{
int i;
for (i = 0; i < cp->size; i++)
if (cp->cache[i].id == id)
return i;
i = cp->size++;
cp->cache = xrealloc(cp->cache, cp->size * sizeof(*cp->cache));
cp->cache[i++].id = id;
return -i;
}
#endif
typedef char* ug_func(char *name, long uid, int bufsize);
static char* get_cached(cache_t *cp, unsigned id, ug_func* fp)
{
int i;
for (i = 0; i < cp->size; i++)
if (cp->cache[i].id == id)
return cp->cache[i].name;
i = cp->size++;
cp->cache = xrealloc(cp->cache, cp->size * sizeof(*cp->cache));
cp->cache[i].id = id;
fp(cp->cache[i].name, id, sizeof(cp->cache[i].name));
return cp->cache[i].name;
}
const char* get_cached_username(uid_t uid)
{
return get_cached(&username, uid, bb_getpwuid);
}
const char* get_cached_groupname(gid_t gid)
{
return get_cached(&groupname, gid, bb_getgrgid);
}
#define PROCPS_BUFSIZE 1024
static int read_to_buf(const char *filename, void *buf)
{
int fd;
/* open_read_close() would do two reads, checking for EOF.
* When you have 10000 /proc/$NUM/stat to read, it isn't desirable */
ssize_t ret = -1;
fd = open(filename, O_RDONLY);
if (fd >= 0) {
ret = read(fd, buf, PROCPS_BUFSIZE-1);
close(fd);
}
((char *)buf)[ret > 0 ? ret : 0] = '\0';
return ret;
}
procps_status_t *alloc_procps_scan(int flags)
{
procps_status_t* sp = xzalloc(sizeof(procps_status_t));
sp->dir = xopendir("/proc");
return sp;
}
void free_procps_scan(procps_status_t* sp)
{
closedir(sp->dir);
free(sp->argv0);
USE_SELINUX(free(sp->context);)
free(sp);
}
#if ENABLE_FEATURE_FAST_TOP
/* We cut a lot of corners here for speed */
static unsigned long fast_strtoul_10(char **endptr)
{
char c;
char *str = *endptr;
unsigned long n = *str - '0';
while ((c = *++str) != ' ')
n = n*10 + (c - '0');
*endptr = str + 1; /* We skip trailing space! */
return n;
}
static char *skip_fields(char *str, int count)
{
do {
while (*str++ != ' ')
continue;
/* we found a space char, str points after it */
} while (--count);
return str;
}
#endif
void BUG_comm_size(void);
procps_status_t *procps_scan(procps_status_t* sp, int flags)
{
struct dirent *entry;
char buf[PROCPS_BUFSIZE];
char filename[sizeof("/proc//cmdline") + sizeof(int)*3];
char *filename_tail;
long tasknice;
unsigned pid;
int n;
struct stat sb;
if (!sp)
sp = alloc_procps_scan(flags);
for (;;) {
entry = readdir(sp->dir);
if (entry == NULL) {
free_procps_scan(sp);
return NULL;
}
pid = bb_strtou(entry->d_name, NULL, 10);
if (errno)
continue;
/* After this point we have to break, not continue
* ("continue" would mean that current /proc/NNN
* is not a valid process info) */
memset(&sp->vsz, 0, sizeof(*sp) - offsetof(procps_status_t, vsz));
sp->pid = pid;
if (!(flags & ~PSSCAN_PID)) break;
#if ENABLE_SELINUX
if (flags & PSSCAN_CONTEXT) {
if (getpidcon(sp->pid, &sp->context) < 0)
sp->context = NULL;
}
#endif
filename_tail = filename + sprintf(filename, "/proc/%d", pid);
if (flags & PSSCAN_UIDGID) {
if (stat(filename, &sb))
break;
/* Need comment - is this effective or real UID/GID? */
sp->uid = sb.st_uid;
sp->gid = sb.st_gid;
}
if (flags & PSSCAN_STAT) {
char *cp, *comm1;
int tty;
#if !ENABLE_FEATURE_FAST_TOP
unsigned long vsz, rss;
#endif
/* see proc(5) for some details on this */
strcpy(filename_tail, "/stat");
n = read_to_buf(filename, buf);
if (n < 0)
break;
cp = strrchr(buf, ')'); /* split into "PID (cmd" and "<rest>" */
/*if (!cp || cp[1] != ' ')
break;*/
cp[0] = '\0';
if (sizeof(sp->comm) < 16)
BUG_comm_size();
comm1 = strchr(buf, '(');
/*if (comm1)*/
safe_strncpy(sp->comm, comm1 + 1, sizeof(sp->comm));
#if !ENABLE_FEATURE_FAST_TOP
n = sscanf(cp+2,
"%c %u " /* state, ppid */
"%u %u %d %*s " /* pgid, sid, tty, tpgid */
"%*s %*s %*s %*s %*s " /* flags, min_flt, cmin_flt, maj_flt, cmaj_flt */
"%lu %lu " /* utime, stime */
"%*s %*s %*s " /* cutime, cstime, priority */
"%ld " /* nice */
"%*s %*s %*s " /* timeout, it_real_value, start_time */
"%lu " /* vsize */
"%lu " /* rss */
/* "%lu %lu %lu %lu %lu %lu " rss_rlim, start_code, end_code, start_stack, kstk_esp, kstk_eip */
/* "%u %u %u %u " signal, blocked, sigignore, sigcatch */
/* "%lu %lu %lu" wchan, nswap, cnswap */
,
sp->state, &sp->ppid,
&sp->pgid, &sp->sid, &tty,
&sp->utime, &sp->stime,
&tasknice,
&vsz,
&rss);
if (n != 10)
break;
sp->vsz = vsz >> 10; /* vsize is in bytes and we want kb */
sp->rss = rss >> 10;
sp->tty_major = (tty >> 8) & 0xfff;
sp->tty_minor = (tty & 0xff) | ((tty >> 12) & 0xfff00);
#else
/* This costs ~100 bytes more but makes top faster by 20%
* If you run 10000 processes, this may be important for you */
sp->state[0] = cp[2];
cp += 4;
sp->ppid = fast_strtoul_10(&cp);
sp->pgid = fast_strtoul_10(&cp);
sp->sid = fast_strtoul_10(&cp);
tty = fast_strtoul_10(&cp);
sp->tty_major = (tty >> 8) & 0xfff;
sp->tty_minor = (tty & 0xff) | ((tty >> 12) & 0xfff00);
cp = skip_fields(cp, 6); /* tpgid, flags, min_flt, cmin_flt, maj_flt, cmaj_flt */
sp->utime = fast_strtoul_10(&cp);
sp->stime = fast_strtoul_10(&cp);
cp = skip_fields(cp, 3); /* cutime, cstime, priority */
tasknice = fast_strtoul_10(&cp);
cp = skip_fields(cp, 3); /* timeout, it_real_value, start_time */
sp->vsz = fast_strtoul_10(&cp) >> 10; /* vsize is in bytes and we want kb */
sp->rss = fast_strtoul_10(&cp) >> 10;
#endif
if (sp->vsz == 0 && sp->state[0] != 'Z')
sp->state[1] = 'W';
else
sp->state[1] = ' ';
if (tasknice < 0)
sp->state[2] = '<';
else if (tasknice) /* > 0 */
sp->state[2] = 'N';
else
sp->state[2] = ' ';
}
#if 0 /* PSSCAN_CMD is not used */
if (flags & (PSSCAN_CMD|PSSCAN_ARGV0)) {
if (sp->argv0) {
free(sp->argv0);
sp->argv0 = NULL;
}
if (sp->cmd) {
free(sp->cmd);
sp->cmd = NULL;
}
strcpy(filename_tail, "/cmdline");
/* TODO: to get rid of size limits, read into malloc buf,
* then realloc it down to real size. */
n = read_to_buf(filename, buf);
if (n <= 0)
break;
if (flags & PSSCAN_ARGV0)
sp->argv0 = xstrdup(buf);
if (flags & PSSCAN_CMD) {
do {
n--;
if ((unsigned char)(buf[n]) < ' ')
buf[n] = ' ';
} while (n);
sp->cmd = xstrdup(buf);
}
}
#else
if (flags & PSSCAN_ARGV0) {
if (sp->argv0) {
free(sp->argv0);
sp->argv0 = NULL;
}
strcpy(filename_tail, "/cmdline");
n = read_to_buf(filename, buf);
if (n <= 0)
break;
if (flags & PSSCAN_ARGV0)
sp->argv0 = xstrdup(buf);
}
#endif
break;
}
return sp;
}
void read_cmdline(char *buf, int col, unsigned pid, const char *comm)
{
ssize_t sz;
char filename[sizeof("/proc//cmdline") + sizeof(int)*3];
sprintf(filename, "/proc/%u/cmdline", pid);
sz = open_read_close(filename, buf, col);
if (sz > 0) {
buf[sz] = '\0';
while (--sz >= 0)
if ((unsigned char)(buf[sz]) < ' ')
buf[sz] = ' ';
} else {
snprintf(buf, col, "[%s]", comm);
}
}
/* from kernel:
// pid comm S ppid pgid sid tty_nr tty_pgrp flg
sprintf(buffer,"%d (%s) %c %d %d %d %d %d %lu %lu \
%lu %lu %lu %lu %lu %ld %ld %ld %ld %d 0 %llu %lu %ld %lu %lu %lu %lu %lu \
%lu %lu %lu %lu %lu %lu %lu %lu %d %d %lu %lu %llu\n",
task->pid,
tcomm,
state,
ppid,
pgid,
sid,
tty_nr,
tty_pgrp,
task->flags,
min_flt,
cmin_flt,
maj_flt,
cmaj_flt,
cputime_to_clock_t(utime),
cputime_to_clock_t(stime),
cputime_to_clock_t(cutime),
cputime_to_clock_t(cstime),
priority,
nice,
num_threads,
// 0,
start_time,
vsize,
mm ? get_mm_rss(mm) : 0,
rsslim,
mm ? mm->start_code : 0,
mm ? mm->end_code : 0,
mm ? mm->start_stack : 0,
esp,
eip,
the rest is some obsolete cruft
*/