libbb: prevent xmalloc_open_read_close from dying on seek failure

start_stop_daemon: use open_read_close instead of xmalloc_open_read_close
start_stop_daemon: use local structure instead of global one

function                                             old     new   delta
check                                               1620    1661     +41
xmalloc_open_read_close                              171     190     +19
start_stop_daemon_main                               976     954     -22
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 2/1 up/down: 60/-22)             Total: 38 bytes

1 files changed, 17 insertions, 23 deletions

diff --git a/debianutils/start_stop_daemon.c b/debianutils/start_stop_daemon.c
index c5c4059a1..9150763cb 100644
--- a/debianutils/start_stop_daemon.c
+++ b/debianutils/start_stop_daemon.c
@@ -32,7 +32,6 @@ struct globals {
         int user_id;
         smallint quiet;
         smallint signal_nr;
-        struct stat execstat;
 };
 #define G (*(struct globals*)&bb_common_bufsiz1)
 #define found             (G.found               )
@@ -43,7 +42,6 @@ struct globals {
 #define user_id           (G.user_id             )
 #define quiet             (G.quiet               )
 #define signal_nr         (G.signal_nr           )
-#define execstat          (G.execstat            )
 #define INIT_G() \
         do { \
                 user_id = -1; \
@@ -53,12 +51,13 @@ struct globals {
 
 static int pid_is_exec(pid_t pid)
 {
-        struct stat st;
+        struct stat st, execstat;
         char buf[sizeof("/proc//exe") + sizeof(int)*3];
 
         sprintf(buf, "/proc/%u/exe", pid);
         if (stat(buf, &st) < 0)
                 return 0;
+        xstat(execname, &execstat);
         if (st.st_dev == execstat.st_dev
          && st.st_ino == execstat.st_ino)
                 return 1;
@@ -78,24 +77,21 @@ static int pid_is_user(int pid)
 
 static int pid_is_cmd(pid_t pid)
 {
-        char fname[sizeof("/proc//stat") + sizeof(int)*3];
-        char *buf;
-        int r = 0;
-
-        sprintf(fname, "/proc/%u/stat", pid);
-        buf = xmalloc_open_read_close(fname, NULL);
-        if (buf) {
-                char *p = strchr(buf, '(');
-                if (p) {
-                        char *pe = strrchr(++p, ')');
-                        if (pe) {
-                                *pe = '\0';
-                                r = !strcmp(p, cmdname);
-                        }
-                }
-                free(buf);
-        }
-        return r;
+        char buf[256]; /* is it big enough? */
+        char *p, *pe;
+
+        sprintf(buf, "/proc/%u/stat", pid);
+        if (open_read_close(buf, buf, sizeof(buf) - 1) < 0)
+                return 0;
+        buf[sizeof(buf) - 1] = '\0'; /* paranoia */
+        p = strchr(buf, '(');
+        if (!p)
+                return 0;
+        pe = strrchr(++p, ')');
+        if (!pe)
+                return 0;
+        *pe = '\0';
+        return !strcmp(p, cmdname);
 }
 
 static void check(int pid)
@@ -303,8 +299,6 @@ int start_stop_daemon_main(int argc ATTRIBUTE_UNUSED, char **argv)
                 if (errno)
                         user_id = xuname2uid(userspec);
         }
-        if (execname)
-                xstat(execname, &execstat);
 
         do_procinit(); /* Both start and stop needs to know current processes */