flag parameters: NONBLOCK in signalfd

This patch adds support for the SFD_NONBLOCK flag to signalfd4.  The
additional changes needed are minimal.

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 <signal.h>
#include <stdio.h>
#include <unistd.h>
#include <sys/syscall.h>

#ifndef __NR_signalfd4
# ifdef __x86_64__
#  define __NR_signalfd4 289
# elif defined __i386__
#  define __NR_signalfd4 327
# else
#  error "need __NR_signalfd4"
# endif
#endif

#define SFD_NONBLOCK O_NONBLOCK

int
main (void)
{
  sigset_t ss;
  sigemptyset (&ss);
  sigaddset (&ss, SIGUSR1);
  int fd = syscall (__NR_signalfd4, -1, &ss, 8, 0);
  if (fd == -1)
    {
      puts ("signalfd4(0) failed");
      return 1;
    }
  int fl = fcntl (fd, F_GETFL);
  if (fl == -1)
    {
      puts ("fcntl failed");
      return 1;
    }
  if (fl & O_NONBLOCK)
    {
      puts ("signalfd4(0) set non-blocking mode");
      return 1;
    }
  close (fd);

  fd = syscall (__NR_signalfd4, -1, &ss, 8, SFD_NONBLOCK);
  if (fd == -1)
    {
      puts ("signalfd4(SFD_NONBLOCK) failed");
      return 1;
    }
  fl = fcntl (fd, F_GETFL);
  if (fl == -1)
    {
      puts ("fcntl failed");
      return 1;
    }
  if ((fl & O_NONBLOCK) == 0)
    {
      puts ("signalfd4(SFD_NONBLOCK) does not set non-blocking mode");
      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>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Ulrich Drepper 2008-07-23 21:29:37 -07:00 committed by Linus Torvalds
parent 77d2720059
commit 5fb5e04926
2 changed files with 4 additions and 3 deletions

View File

@ -211,7 +211,7 @@ asmlinkage long sys_signalfd4(int ufd, sigset_t __user *user_mask,
sigset_t sigmask;
struct signalfd_ctx *ctx;
if (flags & ~SFD_CLOEXEC)
if (flags & ~(SFD_CLOEXEC | SFD_NONBLOCK))
return -EINVAL;
if (sizemask != sizeof(sigset_t) ||
@ -232,7 +232,7 @@ asmlinkage long sys_signalfd4(int ufd, sigset_t __user *user_mask,
* anon_inode_getfd() will install the fd.
*/
ufd = anon_inode_getfd("[signalfd]", &signalfd_fops, ctx,
flags & O_CLOEXEC);
flags & (O_CLOEXEC | O_NONBLOCK));
if (ufd < 0)
kfree(ctx);
} else {

View File

@ -8,11 +8,12 @@
#ifndef _LINUX_SIGNALFD_H
#define _LINUX_SIGNALFD_H
/* For O_CLOEXEC */
/* For O_CLOEXEC and O_NONBLOCK */
#include <linux/fcntl.h>
/* Flags for signalfd4. */
#define SFD_CLOEXEC O_CLOEXEC
#define SFD_NONBLOCK O_NONBLOCK
struct signalfd_siginfo {
__u32 ssi_signo;