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98ebab8b7

Denis Vlasenko
Denis Vlasenko
2007-06-30
FAILED Duration: 16s

Subject

top,ps: improve /proc/PID/cmdinfo reading code

Binary

No binary (build failed)

Architecture & Compiler Flags

Architecture: x86_64-linux-gnu Compiler: gcc (Ubuntu 11.4.0-1ubuntu1~22.04.3) 11.4.0

—

Build Log

(log yok)

Commit Diff GitHub →

include/libbb.h +9 -4libbb/procps.c +34 -1libbb/read.c +3 -3procps/ps.c +24 -39procps/top.c +10 -12
include/libbb.h+9 -4
@@ -836,7 +836,7 @@ enum { COMM_LEN = 16 };
typedef struct {
DIR *dir;
/* Fields are set to 0/NULL if failed to determine (or not requested) */
- char *cmd;
+ /*char *cmd;*/
char *argv0;
/*char *exe;*/
USE_SELINUX(char *context;)
@@ -852,7 +852,9 @@ typedef struct {
unsigned gid;
unsigned tty_major,tty_minor;
char state[4];
- /* basename of executable in exec(2), read from /proc/N/stat */
+ /* basename of executable in exec(2), read from /proc/N/stat
+ * (if executable is symlink or script, it is NOT replaced
+ * by link target or interpreter name) */
char comm[COMM_LEN];
/* user/group? - use passwd/group parsing functions */
} procps_status_t;
@@ -863,9 +865,9 @@ enum {
PSSCAN_SID = 1 << 3,
PSSCAN_UIDGID = 1 << 4,
PSSCAN_COMM = 1 << 5,
- PSSCAN_CMD = 1 << 6,
+ /* PSSCAN_CMD = 1 << 6, - use read_cmdline instead */
PSSCAN_ARGV0 = 1 << 7,
- PSSCAN_EXE = 1 << 8, /* not implemented yet */
+ /* PSSCAN_EXE = 1 << 8, - not implemented */
PSSCAN_STATE = 1 << 9,
PSSCAN_VSZ = 1 << 10,
PSSCAN_RSS = 1 << 11,
@@ -883,6 +885,9 @@ enum {
procps_status_t* alloc_procps_scan(int flags);
void free_procps_scan(procps_status_t* sp);
procps_status_t* procps_scan(procps_status_t* sp, int flags);
+/* Format cmdline (up to col chars) into char buf[col+1] */
+/* Puts [comm] if cmdline is empty (-> process is a kernel thread) */
+void read_cmdline(char *buf, int col, unsigned pid, const char *comm);
pid_t *find_pid_by_name(const char* procName);
pid_t *pidlist_reverse(pid_t *pidList);
libbb/procps.c+34 -1
@@ -102,7 +102,7 @@ procps_status_t *alloc_procps_scan(int flags)
void free_procps_scan(procps_status_t* sp)
{
closedir(sp->dir);
- free(sp->cmd);
+ free(sp->argv0);
USE_SELINUX(free(sp->context);)
free(sp);
}
@@ -266,6 +266,7 @@ procps_status_t *procps_scan(procps_status_t* sp, int flags)
}
+#if 0 /* PSSCAN_CMD is not used */
if (flags & (PSSCAN_CMD|PSSCAN_ARGV0)) {
if (sp->argv0) {
free(sp->argv0);
@@ -292,10 +293,42 @@ procps_status_t *procps_scan(procps_status_t* sp, int flags)
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 \
libbb/read.c+3 -3
@@ -124,11 +124,11 @@ char *xmalloc_reads(int fd, char *buf)
ssize_t read_close(int fd, void *buf, size_t size)
{
- int e;
+ /*int e;*/
size = full_read(fd, buf, size);
- e = errno;
+ /*e = errno;*/
close(fd);
- errno = e;
+ /*errno = e;*/
return size;
}
procps/ps.c+24 -39
@@ -27,11 +27,7 @@ static void func_comm(char *buf, int size, const procps_status_t *ps)
static void func_args(char *buf, int size, const procps_status_t *ps)
{
- buf[0] = '\0';
- if (ps->cmd)
- safe_strncpy(buf, ps->cmd, size+1);
- else if (size >= 2)
- sprintf(buf, "[%.*s]", size-2, ps->comm);
+ read_cmdline(buf, size, ps->pid, ps->comm);
}
static void func_pid(char *buf, int size, const procps_status_t *ps)
@@ -112,25 +108,25 @@ typedef struct {
static const ps_out_t out_spec[] = {
// Mandated by POSIX:
- { 8 , "user" ,"USER" ,func_user ,PSSCAN_UIDGID },
- { 16 , "comm" ,"COMMAND",func_comm ,PSSCAN_COMM },
- { 256 , "args" ,"COMMAND",func_args ,PSSCAN_CMD|PSSCAN_COMM },
- { 5 , "pid" ,"PID" ,func_pid ,PSSCAN_PID },
- { 5 , "ppid" ,"PPID" ,func_ppid ,PSSCAN_PPID },
- { 5 , "pgid" ,"PGID" ,func_pgid ,PSSCAN_PGID },
-// { sizeof("ELAPSED")-1, "etime" ,"ELAPSED",func_etime ,PSSCAN_ },
-// { sizeof("GROUP" )-1, "group" ,"GROUP" ,func_group ,PSSCAN_UIDGID },
-// { sizeof("NI" )-1, "nice" ,"NI" ,func_nice ,PSSCAN_ },
-// { sizeof("%CPU" )-1, "pcpu" ,"%CPU" ,func_pcpu ,PSSCAN_ },
-// { sizeof("RGROUP" )-1, "rgroup","RGROUP" ,func_rgroup,PSSCAN_UIDGID },
-// { sizeof("RUSER" )-1, "ruser" ,"RUSER" ,func_ruser ,PSSCAN_UIDGID },
-// { sizeof("TIME" )-1, "time" ,"TIME" ,func_time ,PSSCAN_ },
- { 6 , "tty" ,"TT" ,func_tty ,PSSCAN_TTY },
- { 4 , "vsz" ,"VSZ" ,func_vsz ,PSSCAN_VSZ },
+ { 8 , "user" ,"USER" ,func_user ,PSSCAN_UIDGID },
+ { 16 , "comm" ,"COMMAND",func_comm ,PSSCAN_COMM },
+ { 256 , "args" ,"COMMAND",func_args ,PSSCAN_COMM },
+ { 5 , "pid" ,"PID" ,func_pid ,PSSCAN_PID },
+ { 5 , "ppid" ,"PPID" ,func_ppid ,PSSCAN_PPID },
+ { 5 , "pgid" ,"PGID" ,func_pgid ,PSSCAN_PGID },
+// { sizeof("ELAPSED")-1, "etime" ,"ELAPSED",func_etime ,PSSCAN_ },
+// { sizeof("GROUP" )-1, "group" ,"GROUP" ,func_group ,PSSCAN_UIDGID },
+// { sizeof("NI" )-1, "nice" ,"NI" ,func_nice ,PSSCAN_ },
+// { sizeof("%CPU" )-1, "pcpu" ,"%CPU" ,func_pcpu ,PSSCAN_ },
+// { sizeof("RGROUP" )-1, "rgroup","RGROUP" ,func_rgroup,PSSCAN_UIDGID },
+// { sizeof("RUSER" )-1, "ruser" ,"RUSER" ,func_ruser ,PSSCAN_UIDGID },
+// { sizeof("TIME" )-1, "time" ,"TIME" ,func_time ,PSSCAN_ },
+ { 6 , "tty" ,"TT" ,func_tty ,PSSCAN_TTY },
+ { 4 , "vsz" ,"VSZ" ,func_vsz ,PSSCAN_VSZ },
// Not mandated by POSIX, but useful:
- { 4 , "rss" ,"RSS" ,func_rss ,PSSCAN_RSS },
+ { 4 , "rss" ,"RSS" ,func_rss ,PSSCAN_RSS },
#if ENABLE_SELINUX
- { 35 , "label" ,"LABEL" ,func_label ,PSSCAN_CONTEXT },
+ { 35 , "label" ,"LABEL" ,func_label ,PSSCAN_CONTEXT },
#endif
};
@@ -386,10 +382,9 @@ int ps_main(int argc, char **argv)
| PSSCAN_UIDGID
| PSSCAN_STATE
| PSSCAN_VSZ
- | PSSCAN_CMD
+ | PSSCAN_COMM
| use_selinux
))) {
- char *namecmd = p->cmd;
#if ENABLE_SELINUX
if (use_selinux) {
len = printf("%5u %-32s %s ",
@@ -408,21 +403,11 @@ int ps_main(int argc, char **argv)
p->pid, user, p->vsz, p->state);
}
- i = terminal_width-len;
-
- if (namecmd && namecmd[0]) {
- if (i < 0)
- i = 0;
- if (strlen(namecmd) > (size_t)i)
- namecmd[i] = '\0';
- puts(namecmd);
- } else {
- namecmd = p->comm;
- if (i < 2)
- i = 2;
- if (strlen(namecmd) > ((size_t)i-2))
- namecmd[i-2] = '\0';
- printf("[%s]\n", namecmd);
+ {
+ char sz = terminal_width - len;
+ char buf[sz + 1];
+ read_cmdline(buf, sz, p->pid, p->comm);
+ puts(buf);
}
}
if (ENABLE_FEATURE_CLEAN_UP)
procps/top.c+10 -12
@@ -40,11 +40,10 @@ typedef struct top_status_t {
unsigned pid, ppid;
unsigned uid;
char state[4];
-/* TODO: read /proc/$PID/cmdline only for processes which are displayed */
- char cmd[64];
+ char comm[COMM_LEN];
} top_status_t;
-typedef struct jiffy_counts_t{
+typedef struct jiffy_counts_t {
unsigned long long usr,nic,sys,idle,iowait,irq,softirq,steal;
unsigned long long total;
unsigned long long busy;
@@ -421,7 +420,7 @@ static void display_status(int count, int scr_width)
/* Ok, all prelim data is ready, go thru the list */
while (count-- > 0) {
- int col = scr_width+1;
+ int col = scr_width;
CALC_STAT(pmem, (s->vsz*pmem_scale + pmem_half) >> pmem_shift);
#if ENABLE_FEATURE_TOP_CPU_USAGE_PERCENTAGE
CALC_STAT(pcpu, (s->pcpu*pcpu_scale + pcpu_half) >> pcpu_shift);
@@ -444,8 +443,11 @@ static void display_status(int count, int scr_width)
, SHOW_STAT(pcpu)
#endif
);
- if (col > 0)
- printf("%.*s", col, s->cmd);
+ if (col > 0) {
+ char buf[col + 1];
+ read_cmdline(buf, col, s->pid, s->comm);
+ fputs(buf, stdout);
+ }
/* printf(" %d/%d %lld/%lld", s->pcpu, total_pcpu,
jif.busy - prev_jif.busy, jif.total - prev_jif.total); */
s++;
@@ -560,12 +562,11 @@ int top_main(int argc, char **argv)
| PSSCAN_UTIME
| PSSCAN_STATE
| PSSCAN_COMM
- | PSSCAN_CMD
| PSSCAN_SID
| PSSCAN_UIDGID
))) {
int n = ntop;
- top = xrealloc(top, (++ntop)*sizeof(top_status_t));
+ top = xrealloc(top, (++ntop) * sizeof(*top));
top[n].pid = p->pid;
top[n].ppid = p->ppid;
top[n].vsz = p->vsz;
@@ -574,10 +575,7 @@ int top_main(int argc, char **argv)
#endif
top[n].uid = p->uid;
strcpy(top[n].state, p->state);
- if (p->cmd)
- safe_strncpy(top[n].cmd, p->cmd, sizeof(top[n].cmd));
- else /* mimic ps */
- sprintf(top[n].cmd, "[%s]", p->comm);
+ strcpy(top[n].comm, p->comm);
}
if (ntop == 0) {
bb_error_msg_and_die("no process info in /proc");