The patch titled
F_DUPFD_CLOEXEC implementation
has been added to the -mm tree. Its filename is
f_dupfd_cloexec-implementation.patch
*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: F_DUPFD_CLOEXEC implementation
From: Ulrich Drepper <drepper@xxxxxxxxxx>
One more small change to extend the availability of creation of file
descriptors with FD_CLOEXEC set. Adding a new command to fcntl() requires
no new system call and the overall impact on code size if minimal.
If this patch gets accepted we will also add this change to the next
revision of the POSIX spec.
To test the patch, use the following little program. Adjust the value of
F_DUPFD_CLOEXEC appropriately.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#ifndef F_DUPFD_CLOEXEC
# define F_DUPFD_CLOEXEC 12
#endif
int
main (int argc, char *argv[])
{
if (argc > 1)
{
if (fcntl (3, F_GETFD) == 0)
{
puts ("descriptor not closed");
exit (1);
}
if (errno != EBADF)
{
puts ("error not EBADF");
exit (1);
}
exit (0);
}
int fd = fcntl (STDOUT_FILENO, F_DUPFD_CLOEXEC, 0);
if (fd == -1 && errno == EINVAL)
{
puts ("F_DUPFD_CLOEXEC not supported");
return 0;
}
if (fd != 3)
{
puts ("program called with descriptors other than 0,1,2");
return 1;
}
execl ("/proc/self/exe", "/proc/self/exe", "1", NULL);
puts ("execl failed");
return 1;
}
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Signed-off-by: Ulrich Drepper <drepper@xxxxxxxxxx>
Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Cc: <linux-arch@xxxxxxxxxxxxxxx>
Cc: Kyle McMartin <kyle@xxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
diff -puN fs/fcntl.c~f_dupfd_cloexec-implementation fs/fcntl.c
--- a/fs/fcntl.c~f_dupfd_cloexec-implementation
+++ a/fs/fcntl.c
@@ -110,7 +110,7 @@ out:
return error;
}
-static int dupfd(struct file *file, unsigned int start)
+static int dupfd(struct file *file, unsigned int start, int cloexec)
{
struct files_struct * files = current->files;
struct fdtable *fdt;
@@ -122,7 +122,10 @@ static int dupfd(struct file *file, unsi
/* locate_fd() may have expanded fdtable, load the ptr */
fdt = files_fdtable(files);
FD_SET(fd, fdt->open_fds);
- FD_CLR(fd, fdt->close_on_exec);
+ if (cloexec)
+ FD_SET(fd, fdt->close_on_exec);
+ else
+ FD_CLR(fd, fdt->close_on_exec);
spin_unlock(&files->file_lock);
fd_install(fd, file);
} else {
@@ -195,7 +198,7 @@ asmlinkage long sys_dup(unsigned int fil
struct file * file = fget(fildes);
if (file)
- ret = dupfd(file, 0);
+ ret = dupfd(file, 0, 0);
return ret;
}
@@ -319,8 +322,9 @@ static long do_fcntl(int fd, unsigned in
switch (cmd) {
case F_DUPFD:
+ case F_DUPFD_CLOEXEC:
get_file(filp);
- err = dupfd(filp, arg);
+ err = dupfd(filp, arg, cmd == F_DUPFD_CLOEXEC);
break;
case F_GETFD:
err = get_close_on_exec(fd) ? FD_CLOEXEC : 0;
diff -puN include/asm-generic/fcntl.h~f_dupfd_cloexec-implementation include/asm-generic/fcntl.h
--- a/include/asm-generic/fcntl.h~f_dupfd_cloexec-implementation
+++ a/include/asm-generic/fcntl.h
@@ -73,6 +73,9 @@
#define F_SETSIG 10 /* for sockets. */
#define F_GETSIG 11 /* for sockets. */
#endif
+#ifndef F_DUPFD_CLOEXEC
+#define F_DUPFD_CLOEXEC 12
+#endif
/* for F_[GET|SET]FL */
#define FD_CLOEXEC 1 /* actually anything with low bit set goes */
_
Patches currently in -mm which might be from drepper@xxxxxxxxxx are
vfs-check-nanoseconds-in-utimensat.patch
f_dupfd_cloexec-implementation.patch
f_dupfd_cloexec-implementation-fix.patch
-
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