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>
diff --git a/fs/signalfd.c b/fs/signalfd.c
index c8609fa..5441a4b 100644
--- a/fs/signalfd.c
+++ b/fs/signalfd.c
@@ -211,7 +211,7 @@
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 @@
* 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 {
