6 files changed, 102 insertions, 0 deletions

diff --git a/include/linux/Kbuild b/include/linux/Kbuild
index 645b3b528150..bcd01f269f60 100644
--- a/include/linux/Kbuild
+++ b/include/linux/Kbuild
@@ -190,6 +190,7 @@ unifdef-y += errno.h
 unifdef-y += errqueue.h
 unifdef-y += ethtool.h
 unifdef-y += eventpoll.h
+unifdef-y += signalfd.h
 unifdef-y += ext2_fs.h
 unifdef-y += ext3_fs.h
 unifdef-y += fb.h
diff --git a/include/linux/init_task.h b/include/linux/init_task.h
index 66e2f0a70814..276ccaa2670c 100644
--- a/include/linux/init_task.h
+++ b/include/linux/init_task.h
@@ -84,6 +84,7 @@ extern struct nsproxy init_nsproxy;
         .count          = ATOMIC_INIT(1),                               \
         .action         = { { { .sa_handler = NULL, } }, },             \
         .siglock        = __SPIN_LOCK_UNLOCKED(sighand.siglock),        \
+        .signalfd_list  = LIST_HEAD_INIT(sighand.signalfd_list),        \
 }
 
 extern struct group_info init_groups;
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 75f44379b7e9..97c0c7da58ef 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -391,6 +391,7 @@ struct sighand_struct {
         atomic_t                count;
         struct k_sigaction      action[_NSIG];
         spinlock_t              siglock;
+        struct list_head        signalfd_list;
 };
 
 struct pacct_struct {
diff --git a/include/linux/signal.h b/include/linux/signal.h
index 3fa0fab4a04b..9a5eac508e5e 100644
--- a/include/linux/signal.h
+++ b/include/linux/signal.h
@@ -233,6 +233,7 @@ static inline int valid_signal(unsigned long sig)
         return sig <= _NSIG ? 1 : 0;
 }
 
+extern int next_signal(struct sigpending *pending, sigset_t *mask);
 extern int group_send_sig_info(int sig, struct siginfo *info, struct task_struct *p);
 extern int __group_send_sig_info(int, struct siginfo *, struct task_struct *);
 extern long do_sigpending(void __user *, unsigned long);
diff --git a/include/linux/signalfd.h b/include/linux/signalfd.h
new file mode 100644
index 000000000000..510429495690
--- /dev/null
+++ b/include/linux/signalfd.h
@@ -0,0 +1,97 @@
+/*
+ *  include/linux/signalfd.h
+ *
+ *  Copyright (C) 2007  Davide Libenzi <davidel@xmailserver.org>
+ *
+ */
+
+#ifndef _LINUX_SIGNALFD_H
+#define _LINUX_SIGNALFD_H
+
+
+struct signalfd_siginfo {
+        __u32 signo;
+        __s32 err;
+        __s32 code;
+        __u32 pid;
+        __u32 uid;
+        __s32 fd;
+        __u32 tid;
+        __u32 band;
+        __u32 overrun;
+        __u32 trapno;
+        __s32 status;
+        __s32 svint;
+        __u64 svptr;
+        __u64 utime;
+        __u64 stime;
+        __u64 addr;
+
+        /*
+         * Pad strcture to 128 bytes. Remember to update the
+         * pad size when you add new memebers. We use a fixed
+         * size structure to avoid compatibility problems with
+         * future versions, and we leave extra space for additional
+         * members. We use fixed size members because this strcture
+         * comes out of a read(2) and we really don't want to have
+         * a compat on read(2).
+         */
+        __u8 __pad[48];
+};
+
+
+#ifdef __KERNEL__
+
+#ifdef CONFIG_SIGNALFD
+
+/*
+ * Deliver the signal to listening signalfd. This must be called
+ * with the sighand lock held. Same are the following that end up
+ * calling signalfd_deliver().
+ */
+void signalfd_deliver(struct task_struct *tsk, int sig);
+
+/*
+ * No need to fall inside signalfd_deliver() if no signal listeners
+ * are available.
+ */
+static inline void signalfd_notify(struct task_struct *tsk, int sig)
+{
+        if (unlikely(!list_empty(&tsk->sighand->signalfd_list)))
+                signalfd_deliver(tsk, sig);
+}
+
+/*
+ * The signal -1 is used to notify the signalfd that the sighand
+ * is on its way to be detached.
+ */
+static inline void signalfd_detach_locked(struct task_struct *tsk)
+{
+        if (unlikely(!list_empty(&tsk->sighand->signalfd_list)))
+                signalfd_deliver(tsk, -1);
+}
+
+static inline void signalfd_detach(struct task_struct *tsk)
+{
+        struct sighand_struct *sighand = tsk->sighand;
+
+        if (unlikely(!list_empty(&sighand->signalfd_list))) {
+                spin_lock_irq(&sighand->siglock);
+                signalfd_deliver(tsk, -1);
+                spin_unlock_irq(&sighand->siglock);
+        }
+}
+
+#else /* CONFIG_SIGNALFD */
+
+#define signalfd_deliver(t, s) do { } while (0)
+#define signalfd_notify(t, s) do { } while (0)
+#define signalfd_detach_locked(t) do { } while (0)
+#define signalfd_detach(t) do { } while (0)
+
+#endif /* CONFIG_SIGNALFD */
+
+#endif /* __KERNEL__ */
+
+#endif /* _LINUX_SIGNALFD_H */
+
diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index 3139f4412297..e049f14a75b7 100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -604,6 +604,7 @@ asmlinkage long sys_get_robust_list(int pid,
 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);
 
 int kernel_execve(const char *filename, char *const argv[], char *const envp[]);