9deb27baed
This patch adds the new signalfd4 syscall. It extends the old signalfd
syscall by one parameter which is meant to hold a flag value. In this
patch the only flag support is SFD_CLOEXEC which causes the close-on-exec
flag for the returned file descriptor to be set.
A new name SFD_CLOEXEC is introduced which in this implementation must
have the same value as O_CLOEXEC.
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_CLOEXEC O_CLOEXEC
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 coe = fcntl (fd, F_GETFD);
if (coe == -1)
{
puts ("fcntl failed");
return 1;
}
if (coe & FD_CLOEXEC)
{
puts ("signalfd4(0) set close-on-exec flag");
return 1;
}
close (fd);
fd = syscall (__NR_signalfd4, -1, &ss, 8, SFD_CLOEXEC);
if (fd == -1)
{
puts ("signalfd4(SFD_CLOEXEC) failed");
return 1;
}
coe = fcntl (fd, F_GETFD);
if (coe == -1)
{
puts ("fcntl failed");
return 1;
}
if ((coe & FD_CLOEXEC) == 0)
{
puts ("signalfd4(SFD_CLOEXEC) does not set close-on-exec flag");
return 1;
}
close (fd);
puts ("OK");
return 0;
}
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
[akpm@linux-foundation.org: add sys_ni stub]
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>
71 lines
1.4 KiB
C
71 lines
1.4 KiB
C
/*
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* include/linux/signalfd.h
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*
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* Copyright (C) 2007 Davide Libenzi <davidel@xmailserver.org>
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*
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*/
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#ifndef _LINUX_SIGNALFD_H
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#define _LINUX_SIGNALFD_H
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/* For O_CLOEXEC */
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#include <linux/fcntl.h>
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/* Flags for signalfd4. */
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#define SFD_CLOEXEC O_CLOEXEC
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struct signalfd_siginfo {
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__u32 ssi_signo;
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__s32 ssi_errno;
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__s32 ssi_code;
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__u32 ssi_pid;
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__u32 ssi_uid;
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__s32 ssi_fd;
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__u32 ssi_tid;
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__u32 ssi_band;
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__u32 ssi_overrun;
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__u32 ssi_trapno;
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__s32 ssi_status;
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__s32 ssi_int;
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__u64 ssi_ptr;
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__u64 ssi_utime;
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__u64 ssi_stime;
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__u64 ssi_addr;
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/*
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* Pad strcture to 128 bytes. Remember to update the
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* pad size when you add new members. We use a fixed
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* size structure to avoid compatibility problems with
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* future versions, and we leave extra space for additional
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* members. We use fixed size members because this strcture
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* comes out of a read(2) and we really don't want to have
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* a compat on read(2).
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*/
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__u8 __pad[48];
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};
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#ifdef __KERNEL__
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#ifdef CONFIG_SIGNALFD
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/*
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* Deliver the signal to listening signalfd.
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*/
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static inline void signalfd_notify(struct task_struct *tsk, int sig)
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{
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if (unlikely(waitqueue_active(&tsk->sighand->signalfd_wqh)))
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wake_up(&tsk->sighand->signalfd_wqh);
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}
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#else /* CONFIG_SIGNALFD */
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static inline void signalfd_notify(struct task_struct *tsk, int sig) { }
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#endif /* CONFIG_SIGNALFD */
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#endif /* __KERNEL__ */
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#endif /* _LINUX_SIGNALFD_H */
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