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authorDenis Vlasenko2006-11-05 00:43:51 +0000
committerDenis Vlasenko2006-11-05 00:43:51 +0000
commit459e4d6cf77940977a064edab60c7162731554fb (patch)
tree5deb7d2b82c280440761cceb4281738867d5631a /libbb
parentfa07680091d20f9da1f8fa2c145dd92b5d62ae09 (diff)
downloadbusybox-459e4d6cf77940977a064edab60c7162731554fb.zip
busybox-459e4d6cf77940977a064edab60c7162731554fb.tar.gz
replace /proc scanning code by more versatile one.
Use it where appropriate. Stop scanning /etc/passwd *for every process*!!! (uid->username) top: reduce memory usage - we won't save unneeded fields from /proc info anymore. Downside: ~+250 bytes of code
Diffstat (limited to 'libbb')
-rw-r--r--libbb/find_pid_by_name.c6
-rw-r--r--libbb/procps.c261
2 files changed, 174 insertions, 93 deletions
diff --git a/libbb/find_pid_by_name.c b/libbb/find_pid_by_name.c
index 05f7f96..e986169 100644
--- a/libbb/find_pid_by_name.c
+++ b/libbb/find_pid_by_name.c
@@ -23,11 +23,11 @@ pid_t* find_pid_by_name(const char* procName)
{
pid_t* pidList;
int i = 0;
- procps_status_t* p;
+ procps_status_t* p = NULL;
pidList = xmalloc(sizeof(*pidList));
- while ((p = procps_scan(0)) != 0) {
- if (strncmp(p->short_cmd, procName, COMM_LEN-1) == 0) {
+ while ((p = procps_scan(p, PSSCAN_PID|PSSCAN_COMM))) {
+ if (strncmp(p->comm, procName, sizeof(p->comm)-1) == 0) {
pidList = xrealloc(pidList, sizeof(*pidList) * (i+2));
pidList[i++] = p->pid;
}
diff --git a/libbb/procps.c b/libbb/procps.c
index 15f7715..dee5638 100644
--- a/libbb/procps.c
+++ b/libbb/procps.c
@@ -11,6 +11,35 @@
#include "libbb.h"
+typedef struct {
+ uid_t uid;
+ char username[12];
+} user_map_t;
+
+static user_map_t *username_cache;
+static int username_cache_size;
+
+void clear_username_cache(void)
+{
+ free(username_cache);
+ username_cache = NULL;
+ username_cache_size = 0;
+}
+
+const char* get_cached_username(uid_t uid)
+{
+ int i;
+ for (i = 0; i < username_cache_size; i++)
+ if (username_cache[i].uid == uid)
+ return username_cache[i].username;
+ i = username_cache_size++;
+ username_cache = xrealloc(username_cache, username_cache_size * sizeof(*username_cache));
+ username_cache[i].uid = uid;
+ bb_getpwuid(username_cache[i].username, uid, sizeof(username_cache[i].username));
+ return username_cache[i].username;
+}
+
+
#define PROCPS_BUFSIZE 1024
static int read_to_buf(const char *filename, void *buf)
@@ -21,119 +50,171 @@ static int read_to_buf(const char *filename, void *buf)
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;
+}
-procps_status_t * procps_scan(int save_user_arg0)
+void free_procps_scan(procps_status_t* sp)
{
- static DIR *dir;
- static procps_status_t ret_status;
+ closedir(sp->dir);
+ free(sp->cmd);
+ free(sp);
+}
+void BUG_comm_size(void);
+procps_status_t* procps_scan(procps_status_t* sp, int flags)
+{
struct dirent *entry;
- char *name;
char buf[PROCPS_BUFSIZE];
- char status[sizeof("/proc//cmdline") + sizeof(int)*3];
- char *status_tail;
- procps_status_t curstatus;
+ char filename[sizeof("/proc//cmdline") + sizeof(int)*3];
+ char *filename_tail;
long tasknice;
- int pid;
+ unsigned pid;
int n;
struct stat sb;
- if (!dir) {
- dir = xopendir("/proc");
- }
+ if (!sp)
+ sp = alloc_procps_scan(flags);
+
for (;;) {
- entry = readdir(dir);
+ entry = readdir(sp->dir);
if (entry == NULL) {
- closedir(dir);
- dir = 0;
- return 0;
+ free_procps_scan(sp);
+ return NULL;
}
- name = entry->d_name;
- if (!(*name >= '0' && *name <= '9'))
+ if (safe_strtou(entry->d_name, &pid))
continue;
- memset(&curstatus, 0, sizeof(procps_status_t));
- pid = atoi(name);
- curstatus.pid = pid;
+ /* After this point we have to break, not continue
+ * ("continue" would mean that current /proc/NNN
+ * is not a valid process info) */
- status_tail = status + sprintf(status, "/proc/%d", pid);
- if (stat(status, &sb))
- continue;
- bb_getpwuid(curstatus.user, sb.st_uid, sizeof(curstatus.user));
+ memset(&sp->rss, 0, sizeof(*sp) - offsetof(procps_status_t, rss));
- /* see proc(5) for some details on this */
- strcpy(status_tail, "/stat");
- n = read_to_buf(status, buf);
- if (n < 0)
- continue;
- name = strrchr(buf, ')'); /* split into "PID (cmd" and "<rest>" */
- if (name == 0 || name[1] != ' ')
- continue;
- *name = 0;
- sscanf(buf, "%*s (%15c", curstatus.short_cmd);
- n = sscanf(name+2,
- "%c %d "
- "%*s %*s %*s %*s " /* pgrp, session, tty, tpgid */
- "%*s %*s %*s %*s %*s " /* flags, min_flt, cmin_flt, maj_flt, cmaj_flt */
-#ifdef CONFIG_FEATURE_TOP_CPU_USAGE_PERCENTAGE
- "%lu %lu " /* utime, stime */
-#else
- "%*s %*s " /* utime, stime */
-#endif
- "%*s %*s %*s " /* cutime, cstime, priority */
- "%ld " /* nice */
- "%*s %*s %*s " /* timeout, it_real_value, start_time */
- "%*s " /* vsize */
- "%ld", /* rss */
- curstatus.state, &curstatus.ppid,
-#ifdef CONFIG_FEATURE_TOP_CPU_USAGE_PERCENTAGE
- &curstatus.utime, &curstatus.stime,
-#endif
- &tasknice,
- &curstatus.rss);
-#ifdef CONFIG_FEATURE_TOP_CPU_USAGE_PERCENTAGE
- if (n != 6)
-#else
- if (n != 4)
-#endif
- continue;
+ sp->pid = pid;
+ if (!(flags & ~PSSCAN_PID)) break;
- if (curstatus.rss == 0 && curstatus.state[0] != 'Z')
- curstatus.state[1] = 'W';
- else
- curstatus.state[1] = ' ';
- if (tasknice < 0)
- curstatus.state[2] = '<';
- else if (tasknice > 0)
- curstatus.state[2] = 'N';
- else
- curstatus.state[2] = ' ';
+ filename_tail = filename + sprintf(filename, "/proc/%d", pid);
+
+ if (flags & PSSCAN_UIDGID) {
+ if (stat(filename, &sb))
+ break;
+ /* Need comment - is this effective or read UID/GID? */
+ sp->uid = sb.st_uid;
+ sp->gid = sb.st_gid;
+ }
+
+ if (flags & PSSCAN_STAT) {
+ char *cp;
+ /* 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();
+ sscanf(buf, "%*s (%15c", sp->comm);
+ n = sscanf(cp+2,
+ "%c %u " /* state, ppid */
+ "%u %u %*s %*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 */
+ "%*s " /* vsize */
+ "%lu", /* rss */
+ sp->state, &sp->ppid,
+ &sp->pgid, &sp->sid,
+ &sp->utime, &sp->stime,
+ &tasknice,
+ &sp->rss);
+ if (n != 8)
+ break;
+
+ if (sp->rss == 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] = ' ';
#ifdef PAGE_SHIFT
- curstatus.rss <<= (PAGE_SHIFT - 10); /* 2**10 = 1kb */
+ sp->rss <<= (PAGE_SHIFT - 10); /* 2**10 = 1kb */
#else
- curstatus.rss *= (getpagesize() >> 10); /* 2**10 = 1kb */
+ sp->rss *= (getpagesize() >> 10); /* 2**10 = 1kb */
#endif
+ }
- if (save_user_arg0) {
- strcpy(status_tail, "/cmdline");
- n = read_to_buf(status, buf);
- if (n > 0) {
- if (buf[n-1]=='\n')
- buf[--n] = 0;
- name = buf;
- while (n) {
- if (((unsigned char)*name) < ' ')
- *name = ' ';
- name++;
- n--;
- }
- *name = 0;
- if (buf[0])
- curstatus.cmd = strdup(buf);
- /* if NULL it work true also */
+ if (flags & PSSCAN_CMD) {
+ free(sp->cmd);
+ sp->cmd = NULL;
+ strcpy(filename_tail, "/cmdline");
+ n = read_to_buf(filename, buf);
+ if (n <= 0)
+ break;
+ if (buf[n-1] == '\n') {
+ if (!--n)
+ break;
+ buf[n] = '\0';
}
+ do {
+ n--;
+ if ((unsigned char)(buf[n]) < ' ')
+ buf[n] = ' ';
+ } while (n);
+ sp->cmd = strdup(buf);
}
- return memcpy(&ret_status, &curstatus, sizeof(procps_status_t));
+ break;
}
+ return sp;
}
+/* 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
+*/