ash: use F_DUPFD_CLOEXEC and O_CLOEXEC

function                                             old     new   delta
setjobctl                                            371     367      -4
setinputfile                                         226     220      -6
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 0/2 up/down: 0/-10)             Total: -10 bytes

Based on patch by Mark Marshall <mark.marshall@omicronenergy.com>

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 16 insertions, 9 deletions

diff --git a/shell/ash.c b/shell/ash.c
index 85690e555..c957b001e 100644
--- a/shell/ash.c
+++ b/shell/ash.c
@@ -258,6 +258,9 @@ typedef long arith_t;
 #ifndef F_DUPFD_CLOEXEC
 # define F_DUPFD_CLOEXEC F_DUPFD
 #endif
+#ifndef O_CLOEXEC
+# define O_CLOEXEC 0
+#endif
 #ifndef PIPE_BUF
 # define PIPE_BUF 4096           /* amount of buffering in a pipe */
 #endif
@@ -3972,12 +3975,13 @@ setjobctl(int on)
                                         goto out;
                 }
                 /* fd is a tty at this point */
-                fd = fcntl(fd, F_DUPFD, 10);
+                fd = fcntl(fd, F_DUPFD_CLOEXEC, 10);
                 if (ofd >= 0) /* if it is "/dev/tty", close. If 0/1/2, don't */
                         close(ofd);
                 if (fd < 0)
                         goto out; /* F_DUPFD failed */
-                close_on_exec_on(fd);
+                if (F_DUPFD_CLOEXEC == F_DUPFD) /* if old libc (w/o F_DUPFD_CLOEXEC) */
+                        close_on_exec_on(fd);
                 while (1) { /* while we are in the background */
                         pgrp = tcgetpgrp(fd);
                         if (pgrp < 0) {
@@ -5427,13 +5431,14 @@ savefd(int from)
         int newfd;
         int err;
 
-        newfd = fcntl(from, F_DUPFD, 10);
+        newfd = fcntl(from, F_DUPFD_CLOEXEC, 10);
         err = newfd < 0 ? errno : 0;
         if (err != EBADF) {
                 if (err)
                         ash_msg_and_raise_perror("%d", from);
                 close(from);
-                fcntl(newfd, F_SETFD, FD_CLOEXEC);
+                if (F_DUPFD_CLOEXEC == F_DUPFD)
+                        close_on_exec_on(newfd);
         }
 
         return newfd;
@@ -5458,7 +5463,7 @@ dup_CLOEXEC(int fd, int avoid_fd)
         newfd = fcntl(fd, F_DUPFD_CLOEXEC, avoid_fd + 1);
         if (newfd >= 0) {
                 if (F_DUPFD_CLOEXEC == F_DUPFD) /* if old libc (w/o F_DUPFD_CLOEXEC) */
-                        fcntl(newfd, F_SETFD, FD_CLOEXEC);
+                        close_on_exec_on(newfd);
         } else { /* newfd < 0 */
                 if (errno == EBUSY)
                         goto repeat;
@@ -5472,7 +5477,7 @@ xdup_CLOEXEC_and_close(int fd, int avoid_fd)
 {
         int newfd;
  repeat:
-        newfd = fcntl(fd, F_DUPFD, avoid_fd + 1);
+        newfd = fcntl(fd, F_DUPFD_CLOEXEC, avoid_fd + 1);
         if (newfd < 0) {
                 if (errno == EBUSY)
                         goto repeat;
@@ -5483,7 +5488,8 @@ xdup_CLOEXEC_and_close(int fd, int avoid_fd)
                         return fd;
                 ash_msg_and_raise_perror("%d", newfd);
         }
-        fcntl(newfd, F_SETFD, FD_CLOEXEC);
+        if (F_DUPFD_CLOEXEC == F_DUPFD)
+                close_on_exec_on(newfd);
         close(fd);
         return newfd;
 }
@@ -10753,7 +10759,7 @@ setinputfile(const char *fname, int flags)
         int fd;
 
         INT_OFF;
-        fd = open(fname, O_RDONLY);
+        fd = open(fname, O_RDONLY | O_CLOEXEC);
         if (fd < 0) {
                 if (flags & INPUT_NOFILE_OK)
                         goto out;
@@ -10762,8 +10768,9 @@ setinputfile(const char *fname, int flags)
         }
         if (fd < 10)
                 fd = savefd(fd);
-        else
+        else if (O_CLOEXEC == 0) /* old libc */
                 close_on_exec_on(fd);
+
         setinputfd(fd, flags & INPUT_PUSH_FILE);
  out:
         INT_ON;