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-rw-r--r--fs/Makefile1
-rw-r--r--fs/exec.c11
-rw-r--r--fs/signalfd.c349
-rw-r--r--include/linux/Kbuild1
-rw-r--r--include/linux/init_task.h1
-rw-r--r--include/linux/sched.h1
-rw-r--r--include/linux/signal.h1
-rw-r--r--include/linux/signalfd.h97
-rw-r--r--include/linux/syscalls.h1
-rw-r--r--init/Kconfig10
-rw-r--r--kernel/exit.c9
-rw-r--r--kernel/fork.c8
-rw-r--r--kernel/signal.c22
-rw-r--r--kernel/sys_ni.c3
14 files changed, 508 insertions, 7 deletions
diff --git a/fs/Makefile b/fs/Makefile
index b5cd46a88cb0..cd8a57aeac04 100644
--- a/fs/Makefile
+++ b/fs/Makefile
@@ -23,6 +23,7 @@ obj-$(CONFIG_INOTIFY) += inotify.o
obj-$(CONFIG_INOTIFY_USER) += inotify_user.o
obj-$(CONFIG_EPOLL) += eventpoll.o
obj-$(CONFIG_ANON_INODES) += anon_inodes.o
+obj-$(CONFIG_SIGNALFD) += signalfd.o
obj-$(CONFIG_COMPAT) += compat.o compat_ioctl.o
nfsd-$(CONFIG_NFSD) := nfsctl.o
diff --git a/fs/exec.c b/fs/exec.c
index 2255dc72deef..955a8eb66d70 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -50,6 +50,7 @@
#include <linux/tsacct_kern.h>
#include <linux/cn_proc.h>
#include <linux/audit.h>
+#include <linux/signalfd.h>
#include <asm/uaccess.h>
#include <asm/mmu_context.h>
@@ -582,6 +583,13 @@ static int de_thread(struct task_struct *tsk)
int count;
/*
+ * Tell all the sighand listeners that this sighand has
+ * been detached. The signalfd_detach() function grabs the
+ * sighand lock, if signal listeners are present on the sighand.
+ */
+ signalfd_detach(tsk);
+
+ /*
* If we don't share sighandlers, then we aren't sharing anything
* and we can just re-use it all.
*/
@@ -757,8 +765,7 @@ no_thread_group:
spin_unlock(&oldsighand->siglock);
write_unlock_irq(&tasklist_lock);
- if (atomic_dec_and_test(&oldsighand->count))
- kmem_cache_free(sighand_cachep, oldsighand);
+ __cleanup_sighand(oldsighand);
}
BUG_ON(!thread_group_leader(tsk));
diff --git a/fs/signalfd.c b/fs/signalfd.c
new file mode 100644
index 000000000000..7cfeab412b45
--- /dev/null
+++ b/fs/signalfd.c
@@ -0,0 +1,349 @@
+/*
+ * fs/signalfd.c
+ *
+ * Copyright (C) 2003 Linus Torvalds
+ *
+ * Mon Mar 5, 2007: Davide Libenzi <davidel@xmailserver.org>
+ * Changed ->read() to return a siginfo strcture instead of signal number.
+ * Fixed locking in ->poll().
+ * Added sighand-detach notification.
+ * Added fd re-use in sys_signalfd() syscall.
+ * Now using anonymous inode source.
+ * Thanks to Oleg Nesterov for useful code review and suggestions.
+ * More comments and suggestions from Arnd Bergmann.
+ */
+
+#include <linux/file.h>
+#include <linux/poll.h>
+#include <linux/init.h>
+#include <linux/fs.h>
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <linux/signal.h>
+#include <linux/list.h>
+#include <linux/anon_inodes.h>
+#include <linux/signalfd.h>
+
+struct signalfd_ctx {
+ struct list_head lnk;
+ wait_queue_head_t wqh;
+ sigset_t sigmask;
+ struct task_struct *tsk;
+};
+
+struct signalfd_lockctx {
+ struct task_struct *tsk;
+ unsigned long flags;
+};
+
+/*
+ * Tries to acquire the sighand lock. We do not increment the sighand
+ * use count, and we do not even pin the task struct, so we need to
+ * do it inside an RCU read lock, and we must be prepared for the
+ * ctx->tsk going to NULL (in signalfd_deliver()), and for the sighand
+ * being detached. We return 0 if the sighand has been detached, or
+ * 1 if we were able to pin the sighand lock.
+ */
+static int signalfd_lock(struct signalfd_ctx *ctx, struct signalfd_lockctx *lk)
+{
+ struct sighand_struct *sighand = NULL;
+
+ rcu_read_lock();
+ lk->tsk = rcu_dereference(ctx->tsk);
+ if (likely(lk->tsk != NULL))
+ sighand = lock_task_sighand(lk->tsk, &lk->flags);
+ rcu_read_unlock();
+
+ if (sighand && !ctx->tsk) {
+ unlock_task_sighand(lk->tsk, &lk->flags);
+ sighand = NULL;
+ }
+
+ return sighand != NULL;
+}
+
+static void signalfd_unlock(struct signalfd_lockctx *lk)
+{
+ unlock_task_sighand(lk->tsk, &lk->flags);
+}
+
+/*
+ * This must be called with the sighand lock held.
+ */
+void signalfd_deliver(struct task_struct *tsk, int sig)
+{
+ struct sighand_struct *sighand = tsk->sighand;
+ struct signalfd_ctx *ctx, *tmp;
+
+ BUG_ON(!sig);
+ list_for_each_entry_safe(ctx, tmp, &sighand->signalfd_list, lnk) {
+ /*
+ * We use a negative signal value as a way to broadcast that the
+ * sighand has been orphaned, so that we can notify all the
+ * listeners about this. Remember the ctx->sigmask is inverted,
+ * so if the user is interested in a signal, that corresponding
+ * bit will be zero.
+ */
+ if (sig < 0) {
+ if (ctx->tsk == tsk) {
+ ctx->tsk = NULL;
+ list_del_init(&ctx->lnk);
+ wake_up(&ctx->wqh);
+ }
+ } else {
+ if (!sigismember(&ctx->sigmask, sig))
+ wake_up(&ctx->wqh);
+ }
+ }
+}
+
+static void signalfd_cleanup(struct signalfd_ctx *ctx)
+{
+ struct signalfd_lockctx lk;
+
+ /*
+ * This is tricky. If the sighand is gone, we do not need to remove
+ * context from the list, the list itself won't be there anymore.
+ */
+ if (signalfd_lock(ctx, &lk)) {
+ list_del(&ctx->lnk);
+ signalfd_unlock(&lk);
+ }
+ kfree(ctx);
+}
+
+static int signalfd_release(struct inode *inode, struct file *file)
+{
+ signalfd_cleanup(file->private_data);
+ return 0;
+}
+
+static unsigned int signalfd_poll(struct file *file, poll_table *wait)
+{
+ struct signalfd_ctx *ctx = file->private_data;
+ unsigned int events = 0;
+ struct signalfd_lockctx lk;
+
+ poll_wait(file, &ctx->wqh, wait);
+
+ /*
+ * Let the caller get a POLLIN in this case, ala socket recv() when
+ * the peer disconnects.
+ */
+ if (signalfd_lock(ctx, &lk)) {
+ if (next_signal(&lk.tsk->pending, &ctx->sigmask) > 0 ||
+ next_signal(&lk.tsk->signal->shared_pending,
+ &ctx->sigmask) > 0)
+ events |= POLLIN;
+ signalfd_unlock(&lk);
+ } else
+ events |= POLLIN;
+
+ return events;
+}
+
+/*
+ * Copied from copy_siginfo_to_user() in kernel/signal.c
+ */
+static int signalfd_copyinfo(struct signalfd_siginfo __user *uinfo,
+ siginfo_t const *kinfo)
+{
+ long err;
+
+ BUILD_BUG_ON(sizeof(struct signalfd_siginfo) != 128);
+
+ /*
+ * Unused memebers should be zero ...
+ */
+ err = __clear_user(uinfo, sizeof(*uinfo));
+
+ /*
+ * If you change siginfo_t structure, please be sure
+ * this code is fixed accordingly.
+ */
+ err |= __put_user(kinfo->si_signo, &uinfo->signo);
+ err |= __put_user(kinfo->si_errno, &uinfo->err);
+ err |= __put_user((short)kinfo->si_code, &uinfo->code);
+ switch (kinfo->si_code & __SI_MASK) {
+ case __SI_KILL:
+ err |= __put_user(kinfo->si_pid, &uinfo->pid);
+ err |= __put_user(kinfo->si_uid, &uinfo->uid);
+ break;
+ case __SI_TIMER:
+ err |= __put_user(kinfo->si_tid, &uinfo->tid);
+ err |= __put_user(kinfo->si_overrun, &uinfo->overrun);
+ err |= __put_user((long)kinfo->si_ptr, &uinfo->svptr);
+ break;
+ case __SI_POLL:
+ err |= __put_user(kinfo->si_band, &uinfo->band);
+ err |= __put_user(kinfo->si_fd, &uinfo->fd);
+ break;
+ case __SI_FAULT:
+ err |= __put_user((long)kinfo->si_addr, &uinfo->addr);
+#ifdef __ARCH_SI_TRAPNO
+ err |= __put_user(kinfo->si_trapno, &uinfo->trapno);
+#endif
+ break;
+ case __SI_CHLD:
+ err |= __put_user(kinfo->si_pid, &uinfo->pid);
+ err |= __put_user(kinfo->si_uid, &uinfo->uid);
+ err |= __put_user(kinfo->si_status, &uinfo->status);
+ err |= __put_user(kinfo->si_utime, &uinfo->utime);
+ err |= __put_user(kinfo->si_stime, &uinfo->stime);
+ break;
+ case __SI_RT: /* This is not generated by the kernel as of now. */
+ case __SI_MESGQ: /* But this is */
+ err |= __put_user(kinfo->si_pid, &uinfo->pid);
+ err |= __put_user(kinfo->si_uid, &uinfo->uid);
+ err |= __put_user((long)kinfo->si_ptr, &uinfo->svptr);
+ break;
+ default: /* this is just in case for now ... */
+ err |= __put_user(kinfo->si_pid, &uinfo->pid);
+ err |= __put_user(kinfo->si_uid, &uinfo->uid);
+ break;
+ }
+
+ return err ? -EFAULT: sizeof(*uinfo);
+}
+
+/*
+ * Returns either the size of a "struct signalfd_siginfo", or zero if the
+ * sighand we are attached to, has been orphaned. The "count" parameter
+ * must be at least the size of a "struct signalfd_siginfo".
+ */
+static ssize_t signalfd_read(struct file *file, char __user *buf, size_t count,
+ loff_t *ppos)
+{
+ struct signalfd_ctx *ctx = file->private_data;
+ ssize_t res = 0;
+ int locked, signo;
+ siginfo_t info;
+ struct signalfd_lockctx lk;
+ DECLARE_WAITQUEUE(wait, current);
+
+ if (count < sizeof(struct signalfd_siginfo))
+ return -EINVAL;
+ locked = signalfd_lock(ctx, &lk);
+ if (!locked)
+ return 0;
+ res = -EAGAIN;
+ signo = dequeue_signal(lk.tsk, &ctx->sigmask, &info);
+ if (signo == 0 && !(file->f_flags & O_NONBLOCK)) {
+ add_wait_queue(&ctx->wqh, &wait);
+ for (;;) {
+ set_current_state(TASK_INTERRUPTIBLE);
+ signo = dequeue_signal(lk.tsk, &ctx->sigmask, &info);
+ if (signo != 0)
+ break;
+ if (signal_pending(current)) {
+ res = -ERESTARTSYS;
+ break;
+ }
+ signalfd_unlock(&lk);
+ schedule();
+ locked = signalfd_lock(ctx, &lk);
+ if (unlikely(!locked)) {
+ /*
+ * Let the caller read zero byte, ala socket
+ * recv() when the peer disconnect. This test
+ * must be done before doing a dequeue_signal(),
+ * because if the sighand has been orphaned,
+ * the dequeue_signal() call is going to crash.
+ */
+ res = 0;
+ break;
+ }
+ }
+ remove_wait_queue(&ctx->wqh, &wait);
+ __set_current_state(TASK_RUNNING);
+ }
+ if (likely(locked))
+ signalfd_unlock(&lk);
+ if (likely(signo))
+ res = signalfd_copyinfo((struct signalfd_siginfo __user *) buf,
+ &info);
+
+ return res;
+}
+
+static const struct file_operations signalfd_fops = {
+ .release = signalfd_release,
+ .poll = signalfd_poll,
+ .read = signalfd_read,
+};
+
+/*
+ * Create a file descriptor that is associated with our signal
+ * state. We can pass it around to others if we want to, but
+ * it will always be _our_ signal state.
+ */
+asmlinkage long sys_signalfd(int ufd, sigset_t __user *user_mask, size_t sizemask)
+{
+ int error;
+ sigset_t sigmask;
+ struct signalfd_ctx *ctx;
+ struct sighand_struct *sighand;
+ struct file *file;
+ struct inode *inode;
+ struct signalfd_lockctx lk;
+
+ if (sizemask != sizeof(sigset_t) ||
+ copy_from_user(&sigmask, user_mask, sizeof(sigmask)))
+ return error = -EINVAL;
+ sigdelsetmask(&sigmask, sigmask(SIGKILL) | sigmask(SIGSTOP));
+ signotset(&sigmask);
+
+ if (ufd == -1) {
+ ctx = kmalloc(sizeof(*ctx), GFP_KERNEL);
+ if (!ctx)
+ return -ENOMEM;
+
+ init_waitqueue_head(&ctx->wqh);
+ ctx->sigmask = sigmask;
+ ctx->tsk = current;
+
+ sighand = current->sighand;
+ /*
+ * Add this fd to the list of signal listeners.
+ */
+ spin_lock_irq(&sighand->siglock);
+ list_add_tail(&ctx->lnk, &sighand->signalfd_list);
+ spin_unlock_irq(&sighand->siglock);
+
+ /*
+ * When we call this, the initialization must be complete, since
+ * anon_inode_getfd() will install the fd.
+ */
+ error = anon_inode_getfd(&ufd, &inode, &file, "[signalfd]",
+ &signalfd_fops, ctx);
+ if (error)
+ goto err_fdalloc;
+ } else {
+ file = fget(ufd);
+ if (!file)
+ return -EBADF;
+ ctx = file->private_data;
+ if (file->f_op != &signalfd_fops) {
+ fput(file);
+ return -EINVAL;
+ }
+ /*
+ * We need to be prepared of the fact that the sighand this fd
+ * is attached to, has been detched. In that case signalfd_lock()
+ * will return 0, and we'll just skip setting the new mask.
+ */
+ if (signalfd_lock(ctx, &lk)) {
+ ctx->sigmask = sigmask;
+ signalfd_unlock(&lk);
+ }
+ wake_up(&ctx->wqh);
+ fput(file);
+ }
+
+ return ufd;
+
+err_fdalloc:
+ signalfd_cleanup(ctx);
+ return error;
+}
+
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[]);
diff --git a/init/Kconfig b/init/Kconfig
index a80bd8326bc6..db707204b751 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -492,6 +492,16 @@ config EPOLL
Disabling this option will cause the kernel to be built without
support for epoll family of system calls.
+config SIGNALFD
+ bool "Enable signalfd() system call" if EMBEDDED
+ depends on ANON_INODES
+ default y
+ help
+ Enable the signalfd() system call that allows to receive signals
+ on a file descriptor.
+
+ If unsure, say Y.
+
config SHMEM
bool "Use full shmem filesystem" if EMBEDDED
default y
diff --git a/kernel/exit.c b/kernel/exit.c
index e93691e9b325..c6d14b8008dd 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -24,6 +24,7 @@
#include <linux/pid_namespace.h>
#include <linux/ptrace.h>
#include <linux/profile.h>
+#include <linux/signalfd.h>
#include <linux/mount.h>
#include <linux/proc_fs.h>
#include <linux/kthread.h>
@@ -83,6 +84,14 @@ static void __exit_signal(struct task_struct *tsk)
sighand = rcu_dereference(tsk->sighand);
spin_lock(&sighand->siglock);
+ /*
+ * Notify that this sighand has been detached. This must
+ * be called with the tsk->sighand lock held. Also, this
+ * access tsk->sighand internally, so it must be called
+ * before tsk->sighand is reset.
+ */
+ signalfd_detach_locked(tsk);
+
posix_cpu_timers_exit(tsk);
if (atomic_dec_and_test(&sig->count))
posix_cpu_timers_exit_group(tsk);
diff --git a/kernel/fork.c b/kernel/fork.c
index 083bf8953ce8..49530e40ea8b 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1422,12 +1422,15 @@ long do_fork(unsigned long clone_flags,
#define ARCH_MIN_MMSTRUCT_ALIGN 0
#endif
-static void sighand_ctor(void *data, struct kmem_cache *cachep, unsigned long flags)
+static void sighand_ctor(void *data, struct kmem_cache *cachep,
+ unsigned long flags)
{
struct sighand_struct *sighand = data;
- if (flags & SLAB_CTOR_CONSTRUCTOR)
+ if (flags & SLAB_CTOR_CONSTRUCTOR) {
spin_lock_init(&sighand->siglock);
+ INIT_LIST_HEAD(&sighand->signalfd_list);
+ }
}
void __init proc_caches_init(void)
@@ -1453,7 +1456,6 @@ void __init proc_caches_init(void)
SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL, NULL);
}
-
/*
* Check constraints on flags passed to the unshare system call and
* force unsharing of additional process context as appropriate.
diff --git a/kernel/signal.c b/kernel/signal.c
index 2ac3a668d9dd..34b7d6abce8f 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -21,6 +21,7 @@
#include <linux/syscalls.h>
#include <linux/ptrace.h>
#include <linux/signal.h>
+#include <linux/signalfd.h>
#include <linux/capability.h>
#include <linux/freezer.h>
#include <linux/pid_namespace.h>
@@ -113,8 +114,7 @@ void recalc_sigpending(void)
/* Given the mask, find the first available signal that should be serviced. */
-static int
-next_signal(struct sigpending *pending, sigset_t *mask)
+int next_signal(struct sigpending *pending, sigset_t *mask)
{
unsigned long i, *s, *m, x;
int sig = 0;
@@ -630,6 +630,12 @@ static int send_signal(int sig, struct siginfo *info, struct task_struct *t,
int ret = 0;
/*
+ * Deliver the signal to listening signalfds. This must be called
+ * with the sighand lock held.
+ */
+ signalfd_notify(t, sig);
+
+ /*
* fast-pathed signals for kernel-internal things like SIGSTOP
* or SIGKILL.
*/
@@ -1280,6 +1286,11 @@ int send_sigqueue(int sig, struct sigqueue *q, struct task_struct *p)
ret = 1;
goto out;
}
+ /*
+ * Deliver the signal to listening signalfds. This must be called
+ * with the sighand lock held.
+ */
+ signalfd_notify(p, sig);
list_add_tail(&q->list, &p->pending.list);
sigaddset(&p->pending.signal, sig);
@@ -1323,6 +1334,11 @@ send_group_sigqueue(int sig, struct sigqueue *q, struct task_struct *p)
q->info.si_overrun++;
goto out;
}
+ /*
+ * Deliver the signal to listening signalfds. This must be called
+ * with the sighand lock held.
+ */
+ signalfd_notify(p, sig);
/*
* Put this signal on the shared-pending queue.
@@ -1983,6 +1999,8 @@ int copy_siginfo_to_user(siginfo_t __user *to, siginfo_t *from)
/*
* If you change siginfo_t structure, please be sure
* this code is fixed accordingly.
+ * Please remember to update the signalfd_copyinfo() function
+ * inside fs/signalfd.c too, in case siginfo_t changes.
* It should never copy any pad contained in the structure
* to avoid security leaks, but must copy the generic
* 3 ints plus the relevant union member.
diff --git a/kernel/sys_ni.c b/kernel/sys_ni.c
index d7306d0f3dfc..807e9bb8fcdb 100644
--- a/kernel/sys_ni.c
+++ b/kernel/sys_ni.c
@@ -141,3 +141,6 @@ cond_syscall(compat_sys_migrate_pages);
cond_syscall(sys_bdflush);
cond_syscall(sys_ioprio_set);
cond_syscall(sys_ioprio_get);
+
+/* New file descriptors */
+cond_syscall(sys_signalfd);