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authorUlrich Drepper <drepper@redhat.com>2008-07-23 21:29:29 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2008-07-24 10:47:28 -0700
commit336dd1f70ff62d7dd8655228caed4c5bfc818c56 (patch)
tree1441b76ea5f08f44167f41867f3555ac53712ebb /fs/fcntl.c
parenta0998b50c3f0b8fdd265c63e0032f86ebe377dbf (diff)
downloadlinux-linaro-336dd1f70ff62d7dd8655228caed4c5bfc818c56.tar.gz
flag parameters: dup2
This patch adds the new dup3 syscall. It extends the old dup2 syscall by one parameter which is meant to hold a flag value. Support for the O_CLOEXEC flag is added in this patch. The following test must be adjusted for architectures other than x86 and x86-64 and in case the syscall numbers changed. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ #include <fcntl.h> #include <stdio.h> #include <time.h> #include <unistd.h> #include <sys/syscall.h> #ifndef __NR_dup3 # ifdef __x86_64__ # define __NR_dup3 292 # elif defined __i386__ # define __NR_dup3 330 # else # error "need __NR_dup3" # endif #endif int main (void) { int fd = syscall (__NR_dup3, 1, 4, 0); if (fd == -1) { puts ("dup3(0) failed"); return 1; } int coe = fcntl (fd, F_GETFD); if (coe == -1) { puts ("fcntl failed"); return 1; } if (coe & FD_CLOEXEC) { puts ("dup3(0) set close-on-exec flag"); return 1; } close (fd); fd = syscall (__NR_dup3, 1, 4, O_CLOEXEC); if (fd == -1) { puts ("dup3(O_CLOEXEC) failed"); return 1; } coe = fcntl (fd, F_GETFD); if (coe == -1) { puts ("fcntl failed"); return 1; } if ((coe & FD_CLOEXEC) == 0) { puts ("dup3(O_CLOEXEC) set close-on-exec flag"); return 1; } close (fd); puts ("OK"); return 0; } ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Signed-off-by: Ulrich Drepper <drepper@redhat.com> Acked-by: Davide Libenzi <davidel@xmailserver.org> Cc: Michael Kerrisk <mtk.manpages@googlemail.com> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/fcntl.c')
-rw-r--r--fs/fcntl.c15
1 files changed, 13 insertions, 2 deletions
diff --git a/fs/fcntl.c b/fs/fcntl.c
index 330a7d78259..9679fcbdeaa 100644
--- a/fs/fcntl.c
+++ b/fs/fcntl.c
@@ -125,13 +125,16 @@ static int dupfd(struct file *file, unsigned int start, int cloexec)
return fd;
}
-asmlinkage long sys_dup2(unsigned int oldfd, unsigned int newfd)
+asmlinkage long sys_dup3(unsigned int oldfd, unsigned int newfd, int flags)
{
int err = -EBADF;
struct file * file, *tofree;
struct files_struct * files = current->files;
struct fdtable *fdt;
+ if ((flags & ~O_CLOEXEC) != 0)
+ return -EINVAL;
+
spin_lock(&files->file_lock);
if (!(file = fcheck(oldfd)))
goto out_unlock;
@@ -163,7 +166,10 @@ asmlinkage long sys_dup2(unsigned int oldfd, unsigned int newfd)
rcu_assign_pointer(fdt->fd[newfd], file);
FD_SET(newfd, fdt->open_fds);
- FD_CLR(newfd, fdt->close_on_exec);
+ if (flags & O_CLOEXEC)
+ FD_SET(newfd, fdt->close_on_exec);
+ else
+ FD_CLR(newfd, fdt->close_on_exec);
spin_unlock(&files->file_lock);
if (tofree)
@@ -181,6 +187,11 @@ out_fput:
goto out;
}
+asmlinkage long sys_dup2(unsigned int oldfd, unsigned int newfd)
+{
+ return sys_dup3(oldfd, newfd, 0);
+}
+
asmlinkage long sys_dup(unsigned int fildes)
{
int ret = -EBADF;