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authorUlrich Drepper <drepper@redhat.com>2008-07-23 21:29:24 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2008-07-24 10:47:27 -0700
commit9deb27baedb79759c3ab9435a7d8b841842d56e9 (patch)
tree1c88393ba30db851ca0bb93c4e656d4e5dbb22b9
parent7d9dbca34240ebb6ff88d8a29c6c7bffd098f0c1 (diff)
downloadlwn-9deb27baedb79759c3ab9435a7d8b841842d56e9.tar.gz
lwn-9deb27baedb79759c3ab9435a7d8b841842d56e9.zip
flag parameters: signalfd
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>
-rw-r--r--arch/x86/ia32/ia32entry.S1
-rw-r--r--arch/x86/kernel/syscall_table_32.S1
-rw-r--r--fs/compat.c14
-rw-r--r--fs/signalfd.c14
-rw-r--r--include/asm-x86/unistd_32.h1
-rw-r--r--include/asm-x86/unistd_64.h2
-rw-r--r--include/linux/signalfd.h5
-rw-r--r--include/linux/syscalls.h1
-rw-r--r--kernel/sys_ni.c1
9 files changed, 34 insertions, 6 deletions
diff --git a/arch/x86/ia32/ia32entry.S b/arch/x86/ia32/ia32entry.S
index 021d71bc69b5..c308128b9251 100644
--- a/arch/x86/ia32/ia32entry.S
+++ b/arch/x86/ia32/ia32entry.S
@@ -826,4 +826,5 @@ ia32_sys_call_table:
.quad sys32_fallocate
.quad compat_sys_timerfd_settime /* 325 */
.quad compat_sys_timerfd_gettime
+ .quad compat_sys_signalfd4
ia32_syscall_end:
diff --git a/arch/x86/kernel/syscall_table_32.S b/arch/x86/kernel/syscall_table_32.S
index adff5562f5fd..c12a36c9fd51 100644
--- a/arch/x86/kernel/syscall_table_32.S
+++ b/arch/x86/kernel/syscall_table_32.S
@@ -326,3 +326,4 @@ ENTRY(sys_call_table)
.long sys_fallocate
.long sys_timerfd_settime /* 325 */
.long sys_timerfd_gettime
+ .long sys_signalfd4
diff --git a/fs/compat.c b/fs/compat.c
index b46604281766..106eba28ec5a 100644
--- a/fs/compat.c
+++ b/fs/compat.c
@@ -2131,9 +2131,9 @@ asmlinkage long compat_sys_epoll_pwait(int epfd,
#ifdef CONFIG_SIGNALFD
-asmlinkage long compat_sys_signalfd(int ufd,
- const compat_sigset_t __user *sigmask,
- compat_size_t sigsetsize)
+asmlinkage long compat_sys_signalfd4(int ufd,
+ const compat_sigset_t __user *sigmask,
+ compat_size_t sigsetsize, int flags)
{
compat_sigset_t ss32;
sigset_t tmp;
@@ -2148,9 +2148,15 @@ asmlinkage long compat_sys_signalfd(int ufd,
if (copy_to_user(ksigmask, &tmp, sizeof(sigset_t)))
return -EFAULT;
- return sys_signalfd(ufd, ksigmask, sizeof(sigset_t));
+ return sys_signalfd4(ufd, ksigmask, sizeof(sigset_t), flags);
}
+asmlinkage long compat_sys_signalfd(int ufd,
+ const compat_sigset_t __user *sigmask,
+ compat_size_t sigsetsize)
+{
+ return compat_sys_signalfd4(ufd, sigmask, sigsetsize, 0);
+}
#endif /* CONFIG_SIGNALFD */
#ifdef CONFIG_TIMERFD
diff --git a/fs/signalfd.c b/fs/signalfd.c
index ddb328b74bde..c8609fa51a13 100644
--- a/fs/signalfd.c
+++ b/fs/signalfd.c
@@ -205,11 +205,15 @@ static const struct file_operations signalfd_fops = {
.read = signalfd_read,
};
-asmlinkage long sys_signalfd(int ufd, sigset_t __user *user_mask, size_t sizemask)
+asmlinkage long sys_signalfd4(int ufd, sigset_t __user *user_mask,
+ size_t sizemask, int flags)
{
sigset_t sigmask;
struct signalfd_ctx *ctx;
+ if (flags & ~SFD_CLOEXEC)
+ return -EINVAL;
+
if (sizemask != sizeof(sigset_t) ||
copy_from_user(&sigmask, user_mask, sizeof(sigmask)))
return -EINVAL;
@@ -228,7 +232,7 @@ asmlinkage long sys_signalfd(int ufd, sigset_t __user *user_mask, size_t sizemas
* anon_inode_getfd() will install the fd.
*/
ufd = anon_inode_getfd("[signalfd]", &signalfd_fops, ctx,
- 0);
+ flags & O_CLOEXEC);
if (ufd < 0)
kfree(ctx);
} else {
@@ -250,3 +254,9 @@ asmlinkage long sys_signalfd(int ufd, sigset_t __user *user_mask, size_t sizemas
return ufd;
}
+
+asmlinkage long sys_signalfd(int ufd, sigset_t __user *user_mask,
+ size_t sizemask)
+{
+ return sys_signalfd4(ufd, user_mask, sizemask, 0);
+}
diff --git a/include/asm-x86/unistd_32.h b/include/asm-x86/unistd_32.h
index 8317d94771d3..c310371f5613 100644
--- a/include/asm-x86/unistd_32.h
+++ b/include/asm-x86/unistd_32.h
@@ -332,6 +332,7 @@
#define __NR_fallocate 324
#define __NR_timerfd_settime 325
#define __NR_timerfd_gettime 326
+#define __NR_signalfd4 327
#ifdef __KERNEL__
diff --git a/include/asm-x86/unistd_64.h b/include/asm-x86/unistd_64.h
index e323994a370f..e0a9b45b2346 100644
--- a/include/asm-x86/unistd_64.h
+++ b/include/asm-x86/unistd_64.h
@@ -641,6 +641,8 @@ __SYSCALL(__NR_timerfd_settime, sys_timerfd_settime)
__SYSCALL(__NR_timerfd_gettime, sys_timerfd_gettime)
#define __NR_paccept 288
__SYSCALL(__NR_paccept, sys_paccept)
+#define __NR_signalfd4 289
+__SYSCALL(__NR_signalfd4, sys_signalfd4)
#ifndef __NO_STUBS
diff --git a/include/linux/signalfd.h b/include/linux/signalfd.h
index ea037f28df91..8b3f7b7420a1 100644
--- a/include/linux/signalfd.h
+++ b/include/linux/signalfd.h
@@ -8,6 +8,11 @@
#ifndef _LINUX_SIGNALFD_H
#define _LINUX_SIGNALFD_H
+/* For O_CLOEXEC */
+#include <linux/fcntl.h>
+
+/* Flags for signalfd4. */
+#define SFD_CLOEXEC O_CLOEXEC
struct signalfd_siginfo {
__u32 ssi_signo;
diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index 2a2a40af6b2c..1c2707797845 100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -610,6 +610,7 @@ asmlinkage long sys_set_robust_list(struct robust_list_head __user *head,
size_t len);
asmlinkage long sys_getcpu(unsigned __user *cpu, unsigned __user *node, struct getcpu_cache __user *cache);
asmlinkage long sys_signalfd(int ufd, sigset_t __user *user_mask, size_t sizemask);
+asmlinkage long sys_signalfd4(int ufd, sigset_t __user *user_mask, size_t sizemask, int flags);
asmlinkage long sys_timerfd_create(int clockid, int flags);
asmlinkage long sys_timerfd_settime(int ufd, int flags,
const struct itimerspec __user *utmr,
diff --git a/kernel/sys_ni.c b/kernel/sys_ni.c
index 2f0b8a2e600f..8627c89ae9e8 100644
--- a/kernel/sys_ni.c
+++ b/kernel/sys_ni.c
@@ -156,6 +156,7 @@ cond_syscall(sys_ioprio_get);
/* New file descriptors */
cond_syscall(sys_signalfd);
+cond_syscall(sys_signalfd4);
cond_syscall(compat_sys_signalfd);
cond_syscall(sys_timerfd_create);
cond_syscall(sys_timerfd_settime);