hush/libbb/procps.c
Denys Vlasenko 62c006d508 libbb/procps.c: make fast_strtoul_10() stop on '\n' too
This time for real :)

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2012-02-28 11:16:21 +01:00

658 lines
17 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 source tree.
*/
#include "libbb.h"
typedef struct id_to_name_map_t {
uid_t id;
char name[USERNAME_MAX_SIZE];
} id_to_name_map_t;
typedef struct cache_t {
id_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 FAST_FUNC 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, uid_t id)
{
int i;
for (i = 0; i < cp->size; i++)
if (cp->cache[i].id == id)
return i;
i = cp->size++;
cp->cache = xrealloc_vector(cp->cache, 2, i);
cp->cache[i++].id = id;
return -i;
}
#endif
static char* get_cached(cache_t *cp, uid_t id,
char* FAST_FUNC x2x_utoa(uid_t id))
{
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_vector(cp->cache, 2, i);
cp->cache[i].id = id;
/* Never fails. Generates numeric string if name isn't found */
safe_strncpy(cp->cache[i].name, x2x_utoa(id), sizeof(cp->cache[i].name));
return cp->cache[i].name;
}
const char* FAST_FUNC get_cached_username(uid_t uid)
{
return get_cached(&username, uid, uid2uname_utoa);
}
const char* FAST_FUNC get_cached_groupname(gid_t gid)
{
return get_cached(&groupname, gid, gid2group_utoa);
}
#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;
}
static procps_status_t* FAST_FUNC alloc_procps_scan(void)
{
unsigned n = getpagesize();
procps_status_t* sp = xzalloc(sizeof(procps_status_t));
sp->dir = xopendir("/proc");
while (1) {
n >>= 1;
if (!n) break;
sp->shift_pages_to_bytes++;
}
sp->shift_pages_to_kb = sp->shift_pages_to_bytes - 10;
return sp;
}
void FAST_FUNC free_procps_scan(procps_status_t* sp)
{
closedir(sp->dir);
#if ENABLE_FEATURE_SHOW_THREADS
if (sp->task_dir)
closedir(sp->task_dir);
#endif
free(sp->argv0);
free(sp->exe);
IF_SELINUX(free(sp->context);)
free(sp);
}
#if ENABLE_FEATURE_TOPMEM || ENABLE_PMAP
static unsigned long fast_strtoul_16(char **endptr)
{
unsigned char c;
char *str = *endptr;
unsigned long n = 0;
/* Need to stop on both ' ' and '\n' */
while ((c = *str++) > ' ') {
c = ((c|0x20) - '0');
if (c > 9)
/* c = c + '0' - 'a' + 10: */
c = c - ('a' - '0' - 10);
n = n*16 + c;
}
*endptr = str; /* We skip trailing space! */
return n;
}
#endif
#if ENABLE_FEATURE_FAST_TOP || ENABLE_FEATURE_TOPMEM || ENABLE_PMAP
/* We cut a lot of corners here for speed */
static unsigned long fast_strtoul_10(char **endptr)
{
unsigned char c;
char *str = *endptr;
unsigned long n = *str - '0';
/* Need to stop on both ' ' and '\n' */
while ((c = *++str) > ' ')
n = n*10 + (c - '0');
*endptr = str + 1; /* We skip trailing space! */
return n;
}
# if ENABLE_FEATURE_FAST_TOP
static long fast_strtol_10(char **endptr)
{
if (**endptr != '-')
return fast_strtoul_10(endptr);
(*endptr)++;
return - (long)fast_strtoul_10(endptr);
}
# endif
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
#if ENABLE_FEATURE_TOPMEM || ENABLE_PMAP
int FAST_FUNC procps_read_smaps(pid_t pid, struct smaprec *total,
void (*cb)(struct smaprec *, void *), void *data)
{
FILE *file;
struct smaprec currec;
char filename[sizeof("/proc/%u/smaps") + sizeof(int)*3];
char buf[PROCPS_BUFSIZE];
#if !ENABLE_PMAP
void (*cb)(struct smaprec *, void *) = NULL;
void *data = NULL;
#endif
sprintf(filename, "/proc/%u/smaps", (int)pid);
file = fopen_for_read(filename);
if (!file)
return 1;
memset(&currec, 0, sizeof(currec));
while (fgets(buf, PROCPS_BUFSIZE, file)) {
// Each mapping datum has this form:
// f7d29000-f7d39000 rw-s FILEOFS M:m INODE FILENAME
// Size: nnn kB
// Rss: nnn kB
// .....
char *tp = buf, *p;
#define SCAN(S, X) \
if (strncmp(tp, S, sizeof(S)-1) == 0) { \
tp = skip_whitespace(tp + sizeof(S)-1); \
total->X += currec.X = fast_strtoul_10(&tp); \
continue; \
}
if (cb) {
SCAN("Pss:" , smap_pss );
SCAN("Swap:" , smap_swap );
}
SCAN("Private_Dirty:", private_dirty);
SCAN("Private_Clean:", private_clean);
SCAN("Shared_Dirty:" , shared_dirty );
SCAN("Shared_Clean:" , shared_clean );
#undef SCAN
tp = strchr(buf, '-');
if (tp) {
// We reached next mapping - the line of this form:
// f7d29000-f7d39000 rw-s FILEOFS M:m INODE FILENAME
if (cb) {
/* If we have a previous record, there's nothing more
* for it, call the callback and clear currec
*/
if (currec.smap_size)
cb(&currec, data);
free(currec.smap_name);
}
memset(&currec, 0, sizeof(currec));
*tp = ' ';
tp = buf;
currec.smap_start = fast_strtoul_16(&tp);
currec.smap_size = (fast_strtoul_16(&tp) - currec.smap_start) >> 10;
strncpy(currec.smap_mode, tp, sizeof(currec.smap_mode)-1);
// skipping "rw-s FILEOFS M:m INODE "
tp = skip_whitespace(skip_fields(tp, 4));
// filter out /dev/something (something != zero)
if (strncmp(tp, "/dev/", 5) != 0 || strcmp(tp, "/dev/zero\n") == 0) {
if (currec.smap_mode[1] == 'w') {
currec.mapped_rw = currec.smap_size;
total->mapped_rw += currec.smap_size;
} else if (currec.smap_mode[1] == '-') {
currec.mapped_ro = currec.smap_size;
total->mapped_ro += currec.smap_size;
}
}
if (strcmp(tp, "[stack]\n") == 0)
total->stack += currec.smap_size;
if (cb) {
p = skip_non_whitespace(tp);
if (p == tp) {
currec.smap_name = xstrdup(" [ anon ]");
} else {
*p = '\0';
currec.smap_name = xstrdup(tp);
}
}
total->smap_size += currec.smap_size;
}
}
fclose(file);
if (cb) {
if (currec.smap_size)
cb(&currec, data);
free(currec.smap_name);
}
return 0;
}
#endif
void BUG_comm_size(void);
procps_status_t* FAST_FUNC procps_scan(procps_status_t* sp, int flags)
{
if (!sp)
sp = alloc_procps_scan();
for (;;) {
struct dirent *entry;
char buf[PROCPS_BUFSIZE];
long tasknice;
unsigned pid;
int n;
char filename[sizeof("/proc/%u/task/%u/cmdline") + sizeof(int)*3 * 2];
char *filename_tail;
#if ENABLE_FEATURE_SHOW_THREADS
if (sp->task_dir) {
entry = readdir(sp->task_dir);
if (entry)
goto got_entry;
closedir(sp->task_dir);
sp->task_dir = NULL;
}
#endif
entry = readdir(sp->dir);
if (entry == NULL) {
free_procps_scan(sp);
return NULL;
}
IF_FEATURE_SHOW_THREADS(got_entry:)
pid = bb_strtou(entry->d_name, NULL, 10);
if (errno)
continue;
#if ENABLE_FEATURE_SHOW_THREADS
if ((flags & PSSCAN_TASKS) && !sp->task_dir) {
/* We found another /proc/PID. Do not use it,
* there will be /proc/PID/task/PID (same PID!),
* so just go ahead and dive into /proc/PID/task. */
sprintf(filename, "/proc/%u/task", pid);
/* Note: if opendir fails, we just go to next /proc/XXX */
sp->task_dir = opendir(filename);
sp->main_thread_pid = pid;
continue;
}
#endif
/* After this point we can:
* "break": stop parsing, return the data
* "continue": try next /proc/XXX
*/
memset(&sp->vsz, 0, sizeof(*sp) - offsetof(procps_status_t, vsz));
sp->pid = pid;
if (!(flags & ~PSSCAN_PID))
break; /* we needed only pid, we got it */
#if ENABLE_SELINUX
if (flags & PSSCAN_CONTEXT) {
if (getpidcon(sp->pid, &sp->context) < 0)
sp->context = NULL;
}
#endif
#if ENABLE_FEATURE_SHOW_THREADS
if (sp->task_dir)
filename_tail = filename + sprintf(filename, "/proc/%u/task/%u/", sp->main_thread_pid, pid);
else
#endif
filename_tail = filename + sprintf(filename, "/proc/%u/", pid);
if (flags & PSSCAN_UIDGID) {
struct stat sb;
if (stat(filename, &sb))
continue; /* process probably exited */
/* Effective UID/GID, not real */
sp->uid = sb.st_uid;
sp->gid = sb.st_gid;
}
/* These are all retrieved from proc/NN/stat in one go: */
if (flags & (PSSCAN_PPID | PSSCAN_PGID | PSSCAN_SID
| PSSCAN_COMM | PSSCAN_STATE
| PSSCAN_VSZ | PSSCAN_RSS
| PSSCAN_STIME | PSSCAN_UTIME | PSSCAN_START_TIME
| PSSCAN_TTY | PSSCAN_NICE
| PSSCAN_CPU)
) {
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)
continue; /* process probably exited */
cp = strrchr(buf, ')'); /* split into "PID (cmd" and "<rest>" */
/*if (!cp || cp[1] != ' ')
continue;*/
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 " /* timeout, it_real_value */
"%lu " /* start_time */
"%lu " /* vsize */
"%lu " /* rss */
# if ENABLE_FEATURE_TOP_SMP_PROCESS
"%*s %*s %*s %*s %*s %*s " /*rss_rlim, start_code, end_code, start_stack, kstk_esp, kstk_eip */
"%*s %*s %*s %*s " /*signal, blocked, sigignore, sigcatch */
"%*s %*s %*s %*s " /*wchan, nswap, cnswap, exit_signal */
"%d" /*cpu last seen on*/
# endif
,
sp->state, &sp->ppid,
&sp->pgid, &sp->sid, &tty,
&sp->utime, &sp->stime,
&tasknice,
&sp->start_time,
&vsz,
&rss
# if ENABLE_FEATURE_TOP_SMP_PROCESS
, &sp->last_seen_on_cpu
# endif
);
if (n < 11)
continue; /* bogus data, get next /proc/XXX */
# if ENABLE_FEATURE_TOP_SMP_PROCESS
if (n < 11+15)
sp->last_seen_on_cpu = 0;
# endif
/* vsz is in bytes and we want kb */
sp->vsz = vsz >> 10;
/* vsz is in bytes but rss is in *PAGES*! Can you believe that? */
sp->rss = rss << sp->shift_pages_to_kb;
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_strtol_10(&cp);
cp = skip_fields(cp, 2); /* timeout, it_real_value */
sp->start_time = fast_strtoul_10(&cp);
/* vsz is in bytes and we want kb */
sp->vsz = fast_strtoul_10(&cp) >> 10;
/* vsz is in bytes but rss is in *PAGES*! Can you believe that? */
sp->rss = fast_strtoul_10(&cp) << sp->shift_pages_to_kb;
# if ENABLE_FEATURE_TOP_SMP_PROCESS
/* (6): rss_rlim, start_code, end_code, start_stack, kstk_esp, kstk_eip */
/* (4): signal, blocked, sigignore, sigcatch */
/* (4): wchan, nswap, cnswap, exit_signal */
cp = skip_fields(cp, 14);
//FIXME: is it safe to assume this field exists?
sp->last_seen_on_cpu = fast_strtoul_10(&cp);
# endif
#endif /* FEATURE_FAST_TOP */
#if ENABLE_FEATURE_PS_ADDITIONAL_COLUMNS
sp->niceness = tasknice;
#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 ENABLE_FEATURE_TOPMEM
if (flags & PSSCAN_SMAPS)
procps_read_smaps(pid, &sp->smaps, NULL, NULL);
#endif /* TOPMEM */
#if ENABLE_FEATURE_PS_ADDITIONAL_COLUMNS
if (flags & PSSCAN_RUIDGID) {
FILE *file;
strcpy(filename_tail, "status");
file = fopen_for_read(filename);
if (file) {
while (fgets(buf, sizeof(buf), file)) {
char *tp;
#define SCAN_TWO(str, name, statement) \
if (strncmp(buf, str, sizeof(str)-1) == 0) { \
tp = skip_whitespace(buf + sizeof(str)-1); \
sscanf(tp, "%u", &sp->name); \
statement; \
}
SCAN_TWO("Uid:", ruid, continue);
SCAN_TWO("Gid:", rgid, break);
#undef SCAN_TWO
}
fclose(file);
}
}
#endif /* PS_ADDITIONAL_COLUMNS */
if (flags & PSSCAN_EXE) {
strcpy(filename_tail, "exe");
free(sp->exe);
sp->exe = xmalloc_readlink(filename);
}
/* Note: if /proc/PID/cmdline is empty,
* code below "breaks". Therefore it must be
* the last code to parse /proc/PID/xxx data
* (we used to have /proc/PID/exe parsing after it
* and were getting stale sp->exe).
*/
#if 0 /* PSSCAN_CMD is not used */
if (flags & (PSSCAN_CMD|PSSCAN_ARGV0)) {
free(sp->argv0);
sp->argv0 = NULL;
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|PSSCAN_ARGVN)) {
free(sp->argv0);
sp->argv0 = NULL;
strcpy(filename_tail, "cmdline");
n = read_to_buf(filename, buf);
if (n <= 0)
break;
if (flags & PSSCAN_ARGVN) {
sp->argv_len = n;
sp->argv0 = xmalloc(n + 1);
memcpy(sp->argv0, buf, n + 1);
/* sp->argv0[n] = '\0'; - buf has it */
} else {
sp->argv_len = 0;
sp->argv0 = xstrdup(buf);
}
}
#endif
break;
} /* for (;;) */
return sp;
}
void FAST_FUNC read_cmdline(char *buf, int col, unsigned pid, const char *comm)
{
int sz;
char filename[sizeof("/proc/%u/cmdline") + sizeof(int)*3];
sprintf(filename, "/proc/%u/cmdline", pid);
sz = open_read_close(filename, buf, col - 1);
if (sz > 0) {
const char *base;
int comm_len;
buf[sz] = '\0';
while (--sz >= 0 && buf[sz] == '\0')
continue;
base = bb_basename(buf); /* before we replace argv0's NUL with space */
while (sz >= 0) {
if ((unsigned char)(buf[sz]) < ' ')
buf[sz] = ' ';
sz--;
}
/* If comm differs from argv0, prepend "{comm} ".
* It allows to see thread names set by prctl(PR_SET_NAME).
*/
if (base[0] == '-') /* "-sh" (login shell)? */
base++;
comm_len = strlen(comm);
/* Why compare up to comm_len, not COMM_LEN-1?
* Well, some processes rewrite argv, and use _spaces_ there
* while rewriting. (KDE is observed to do it).
* I prefer to still treat argv0 "process foo bar"
* as 'equal' to comm "process".
*/
if (strncmp(base, comm, comm_len) != 0) {
comm_len += 3;
if (col > comm_len)
memmove(buf + comm_len, buf, col - comm_len);
snprintf(buf, col, "{%s}", comm);
if (col <= comm_len)
return;
buf[comm_len - 1] = ' ';
buf[col - 1] = '\0';
}
} 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
*/