Thread (51 messages) 51 messages, 10 authors, 2016-03-20
STALE3762d

[PATCH 01/13] signals: distinguish signals sent due to i/o via io_send_sig()

From: Benjamin LaHaise <bcrl@kvack.org>
Date: 2016-01-11 22:06:32
Also in: linux-fsdevel, linux-mm, lkml
Subsystem: atm, audit subsystem, drm drivers, drm drivers and misc gpu patches, drm ttm subsystem, exec & binfmt api, elf, filesystems (vfs and infrastructure), fuse filesystem [core], memory management, networking [general], networking [unix sockets], page cache, scheduler, sctp protocol, the rest, x.25 stack · Maintainers: Chas Williams, Paul Moore, Eric Paris, David Airlie, Simona Vetter, Maarten Lankhorst, Maxime Ripard, Thomas Zimmermann, Christian Koenig, Huang Rui, Kees Cook, Alexander Viro, Christian Brauner, Miklos Szeredi, Andrew Morton, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Kuniyuki Iwashima, Matthew Wilcox, Jan Kara, Ingo Molnar, Peter Zijlstra, Juri Lelli, Vincent Guittot, Marcelo Ricardo Leitner, Xin Long, Linus Torvalds, Martin Schiller 

In preparation for thread based aio support, make the callers of
send_sig() that are sending a signal as a direct consequence of a
read or write operation (typically for SIGPIPE or SIGXFS) use a
separate helper of io_send_sig().  This will make it possible for
the thread based aio operations to direct these signals to the
process that actually submitted the aio request.

Signed-off-by: Benjamin LaHaise <redacted>
Signed-off-by: Benjamin LaHaise <bcrl@kvack.org>
---
 drivers/gpu/drm/drm_lock.c     |  2 +-
 drivers/gpu/drm/ttm/ttm_lock.c |  6 +++---
 fs/attr.c                      |  2 +-
 fs/binfmt_flat.c               |  2 +-
 fs/fuse/dev.c                  |  2 +-
 fs/pipe.c                      |  4 ++--
 fs/splice.c                    |  8 ++++----
 include/linux/sched.h          |  1 +
 kernel/auditsc.c               |  6 +++---
 kernel/signal.c                | 14 ++++++++++++++
 mm/filemap.c                   |  6 ++++--
 net/atm/common.c               |  4 ++--
 net/ax25/af_ax25.c             |  2 +-
 net/caif/caif_socket.c         |  2 +-
 net/core/stream.c              |  2 +-
 net/decnet/af_decnet.c         |  2 +-
 net/irda/af_irda.c             |  4 ++--
 net/netrom/af_netrom.c         |  2 +-
 net/rose/af_rose.c             |  2 +-
 net/sctp/socket.c              |  2 +-
 net/unix/af_unix.c             |  4 ++--
 net/x25/af_x25.c               |  2 +-
 22 files changed, 49 insertions(+), 32 deletions(-)

diff --git a/drivers/gpu/drm/drm_lock.c b/drivers/gpu/drm/drm_lock.c
index daa2ff1..3565563 100644
--- a/drivers/gpu/drm/drm_lock.c
+++ b/drivers/gpu/drm/drm_lock.c
@@ -83,7 +83,7 @@ int drm_legacy_lock(struct drm_device *dev, void *data,
 		__set_current_state(TASK_INTERRUPTIBLE);
 		if (!master->lock.hw_lock) {
 			/* Device has been unregistered */
-			send_sig(SIGTERM, current, 0);
+			io_send_sig(SIGTERM);
 			ret = -EINTR;
 			break;
 		}
diff --git a/drivers/gpu/drm/ttm/ttm_lock.c b/drivers/gpu/drm/ttm/ttm_lock.c
index f154fb1..816be91 100644
--- a/drivers/gpu/drm/ttm/ttm_lock.c
+++ b/drivers/gpu/drm/ttm/ttm_lock.c
@@ -68,7 +68,7 @@ static bool __ttm_read_lock(struct ttm_lock *lock)
 
 	spin_lock(&lock->lock);
 	if (unlikely(lock->kill_takers)) {
-		send_sig(lock->signal, current, 0);
+		io_send_sig(lock->signal);
 		spin_unlock(&lock->lock);
 		return false;
 	}
@@ -101,7 +101,7 @@ static bool __ttm_read_trylock(struct ttm_lock *lock, bool *locked)
 
 	spin_lock(&lock->lock);
 	if (unlikely(lock->kill_takers)) {
-		send_sig(lock->signal, current, 0);
+		io_send_sig(lock->signal);
 		spin_unlock(&lock->lock);
 		return false;
 	}
@@ -151,7 +151,7 @@ static bool __ttm_write_lock(struct ttm_lock *lock)
 
 	spin_lock(&lock->lock);
 	if (unlikely(lock->kill_takers)) {
-		send_sig(lock->signal, current, 0);
+		io_send_sig(lock->signal);
 		spin_unlock(&lock->lock);
 		return false;
 	}
diff --git a/fs/attr.c b/fs/attr.c
index 6530ced..0c63049 100644
--- a/fs/attr.c
+++ b/fs/attr.c
@@ -118,7 +118,7 @@ int inode_newsize_ok(const struct inode *inode, loff_t offset)
 
 	return 0;
 out_sig:
-	send_sig(SIGXFSZ, current, 0);
+	io_send_sig(SIGXFSZ);
 out_big:
 	return -EFBIG;
 }
diff --git a/fs/binfmt_flat.c b/fs/binfmt_flat.c
index f723cd3..51cf839 100644
--- a/fs/binfmt_flat.c
+++ b/fs/binfmt_flat.c
@@ -373,7 +373,7 @@ calc_reloc(unsigned long r, struct lib_info *p, int curid, int internalp)
 
 failed:
 	printk(", killing %s!\n", current->comm);
-	send_sig(SIGSEGV, current, 0);
+	io_send_sig(SIGSEGV);
 
 	return RELOC_FAILED;
 }
diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
index ebb5e37..20ffc52 100644
--- a/fs/fuse/dev.c
+++ b/fs/fuse/dev.c
@@ -1391,7 +1391,7 @@ static ssize_t fuse_dev_splice_read(struct file *in, loff_t *ppos,
 	pipe_lock(pipe);
 
 	if (!pipe->readers) {
-		send_sig(SIGPIPE, current, 0);
+		io_send_sig(SIGPIPE);
 		if (!ret)
 			ret = -EPIPE;
 		goto out_unlock;
diff --git a/fs/pipe.c b/fs/pipe.c
index 42cf8dd..e55ed9a 100644
--- a/fs/pipe.c
+++ b/fs/pipe.c
@@ -351,7 +351,7 @@ pipe_write(struct kiocb *iocb, struct iov_iter *from)
 	__pipe_lock(pipe);
 
 	if (!pipe->readers) {
-		send_sig(SIGPIPE, current, 0);
+		io_send_sig(SIGPIPE);
 		ret = -EPIPE;
 		goto out;
 	}
@@ -386,7 +386,7 @@ pipe_write(struct kiocb *iocb, struct iov_iter *from)
 		int bufs;
 
 		if (!pipe->readers) {
-			send_sig(SIGPIPE, current, 0);
+			io_send_sig(SIGPIPE);
 			if (!ret)
 				ret = -EPIPE;
 			break;
diff --git a/fs/splice.c b/fs/splice.c
index 4cf700d..336db78 100644
--- a/fs/splice.c
+++ b/fs/splice.c
@@ -193,7 +193,7 @@ ssize_t splice_to_pipe(struct pipe_inode_info *pipe,
 
 	for (;;) {
 		if (!pipe->readers) {
-			send_sig(SIGPIPE, current, 0);
+			io_send_sig(SIGPIPE);
 			if (!ret)
 				ret = -EPIPE;
 			break;
@@ -1769,7 +1769,7 @@ static int opipe_prep(struct pipe_inode_info *pipe, unsigned int flags)
 
 	while (pipe->nrbufs >= pipe->buffers) {
 		if (!pipe->readers) {
-			send_sig(SIGPIPE, current, 0);
+			io_send_sig(SIGPIPE);
 			ret = -EPIPE;
 			break;
 		}
@@ -1820,7 +1820,7 @@ retry:
 
 	do {
 		if (!opipe->readers) {
-			send_sig(SIGPIPE, current, 0);
+			io_send_sig(SIGPIPE);
 			if (!ret)
 				ret = -EPIPE;
 			break;
@@ -1924,7 +1924,7 @@ static int link_pipe(struct pipe_inode_info *ipipe,
 
 	do {
 		if (!opipe->readers) {
-			send_sig(SIGPIPE, current, 0);
+			io_send_sig(SIGPIPE);
 			if (!ret)
 				ret = -EPIPE;
 			break;
diff --git a/include/linux/sched.h b/include/linux/sched.h
index edad7a4..6376d58 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -2502,6 +2502,7 @@ extern __must_check bool do_notify_parent(struct task_struct *, int);
 extern void __wake_up_parent(struct task_struct *p, struct task_struct *parent);
 extern void force_sig(int, struct task_struct *);
 extern int send_sig(int, struct task_struct *, int);
+extern int io_send_sig(int signal);
 extern int zap_other_threads(struct task_struct *p);
 extern struct sigqueue *sigqueue_alloc(void);
 extern void sigqueue_free(struct sigqueue *);
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index b86cc04..8b4a3ea 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -1025,7 +1025,7 @@ static int audit_log_single_execve_arg(struct audit_context *context,
 	 * any.
 	 */
 	if (WARN_ON_ONCE(len < 0 || len > MAX_ARG_STRLEN - 1)) {
-		send_sig(SIGKILL, current, 0);
+		io_send_sig(SIGKILL);
 		return -1;
 	}
 
@@ -1043,7 +1043,7 @@ static int audit_log_single_execve_arg(struct audit_context *context,
 		 */
 		if (ret) {
 			WARN_ON(1);
-			send_sig(SIGKILL, current, 0);
+			io_send_sig(SIGKILL);
 			return -1;
 		}
 		buf[to_send] = '\0';
@@ -1107,7 +1107,7 @@ static int audit_log_single_execve_arg(struct audit_context *context,
 			ret = 0;
 		if (ret) {
 			WARN_ON(1);
-			send_sig(SIGKILL, current, 0);
+			io_send_sig(SIGKILL);
 			return -1;
 		}
 		buf[to_send] = '\0';
diff --git a/kernel/signal.c b/kernel/signal.c
index f3f1f7a..7c14cb4 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -1422,6 +1422,20 @@ int send_sig_info(int sig, struct siginfo *info, struct task_struct *p)
 	return do_send_sig_info(sig, info, p, false);
 }
 
+/* io_send_sig: send a signal caused by an i/o operation
+ *
+ * Use this helper when a signal is being sent to the task that is responsible
+ * for aer initiated operation.  Most commonly this is used to send signals
+ * like SIGPIPE or SIGXFS that are the result of attempting a read or write
+ * operation.  This is used by aio to direct a signal to the correct task in
+ * the case of async operations.
+ */
+int io_send_sig(int sig)
+{
+	return send_sig(sig, current, 0);
+}
+EXPORT_SYMBOL(io_send_sig);
+
 #define __si_special(priv) \
 	((priv) ? SEND_SIG_PRIV : SEND_SIG_NOINFO)
 
diff --git a/mm/filemap.c b/mm/filemap.c
index 1bb0076..089ccd85 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -2343,7 +2343,7 @@ inline ssize_t generic_write_checks(struct kiocb *iocb, struct iov_iter *from)
 
 	if (limit != RLIM_INFINITY) {
 		if (iocb->ki_pos >= limit) {
-			send_sig(SIGXFSZ, current, 0);
+			io_send_sig(SIGXFSZ);
 			return -EFBIG;
 		}
 		iov_iter_truncate(from, limit - (unsigned long)pos);
@@ -2354,8 +2354,10 @@ inline ssize_t generic_write_checks(struct kiocb *iocb, struct iov_iter *from)
 	 */
 	if (unlikely(pos + iov_iter_count(from) > MAX_NON_LFS &&
 				!(file->f_flags & O_LARGEFILE))) {
-		if (pos >= MAX_NON_LFS)
+		if (pos >= MAX_NON_LFS) {
+			io_send_sig(SIGXFSZ);
 			return -EFBIG;
+		}
 		iov_iter_truncate(from, MAX_NON_LFS - (unsigned long)pos);
 	}
 
diff --git a/net/atm/common.c b/net/atm/common.c
index 49a872d..3eef736 100644
--- a/net/atm/common.c
+++ b/net/atm/common.c
@@ -591,7 +591,7 @@ int vcc_sendmsg(struct socket *sock, struct msghdr *m, size_t size)
 	    test_bit(ATM_VF_CLOSE, &vcc->flags) ||
 	    !test_bit(ATM_VF_READY, &vcc->flags)) {
 		error = -EPIPE;
-		send_sig(SIGPIPE, current, 0);
+		io_send_sig(SIGPIPE);
 		goto out;
 	}
 	if (!size) {
@@ -620,7 +620,7 @@ int vcc_sendmsg(struct socket *sock, struct msghdr *m, size_t size)
 		    test_bit(ATM_VF_CLOSE, &vcc->flags) ||
 		    !test_bit(ATM_VF_READY, &vcc->flags)) {
 			error = -EPIPE;
-			send_sig(SIGPIPE, current, 0);
+			io_send_sig(SIGPIPE);
 			break;
 		}
 		prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
diff --git a/net/ax25/af_ax25.c b/net/ax25/af_ax25.c
index fbd0acf..8dfd84c 100644
--- a/net/ax25/af_ax25.c
+++ b/net/ax25/af_ax25.c
@@ -1457,7 +1457,7 @@ static int ax25_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
 	}
 
 	if (sk->sk_shutdown & SEND_SHUTDOWN) {
-		send_sig(SIGPIPE, current, 0);
+		io_send_sig(SIGPIPE);
 		err = -EPIPE;
 		goto out;
 	}
diff --git a/net/caif/caif_socket.c b/net/caif/caif_socket.c
index aa209b1..ba8d8e2 100644
--- a/net/caif/caif_socket.c
+++ b/net/caif/caif_socket.c
@@ -663,7 +663,7 @@ static int caif_stream_sendmsg(struct socket *sock, struct msghdr *msg,
 
 pipe_err:
 	if (sent == 0 && !(msg->msg_flags&MSG_NOSIGNAL))
-		send_sig(SIGPIPE, current, 0);
+		io_send_sig(SIGPIPE);
 	err = -EPIPE;
 out_err:
 	return sent ? : err;
diff --git a/net/core/stream.c b/net/core/stream.c
index b96f7a7..6b24f6d 100644
--- a/net/core/stream.c
+++ b/net/core/stream.c
@@ -182,7 +182,7 @@ int sk_stream_error(struct sock *sk, int flags, int err)
 	if (err == -EPIPE)
 		err = sock_error(sk) ? : -EPIPE;
 	if (err == -EPIPE && !(flags & MSG_NOSIGNAL))
-		send_sig(SIGPIPE, current, 0);
+		io_send_sig(SIGPIPE);
 	return err;
 }
 EXPORT_SYMBOL(sk_stream_error);
diff --git a/net/decnet/af_decnet.c b/net/decnet/af_decnet.c
index 13d6b1a..47ca404 100644
--- a/net/decnet/af_decnet.c
+++ b/net/decnet/af_decnet.c
@@ -1954,7 +1954,7 @@ static int dn_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
 	if (sk->sk_shutdown & SEND_SHUTDOWN) {
 		err = -EPIPE;
 		if (!(flags & MSG_NOSIGNAL))
-			send_sig(SIGPIPE, current, 0);
+			io_send_sig(SIGPIPE);
 		goto out_err;
 	}
 
diff --git a/net/irda/af_irda.c b/net/irda/af_irda.c
index 923abd6..f9c6b55 100644
--- a/net/irda/af_irda.c
+++ b/net/irda/af_irda.c
@@ -1539,7 +1539,7 @@ static int irda_sendmsg_dgram(struct socket *sock, struct msghdr *msg,
 	lock_sock(sk);
 
 	if (sk->sk_shutdown & SEND_SHUTDOWN) {
-		send_sig(SIGPIPE, current, 0);
+		io_send_sig(SIGPIPE);
 		err = -EPIPE;
 		goto out;
 	}
@@ -1622,7 +1622,7 @@ static int irda_sendmsg_ultra(struct socket *sock, struct msghdr *msg,
 
 	err = -EPIPE;
 	if (sk->sk_shutdown & SEND_SHUTDOWN) {
-		send_sig(SIGPIPE, current, 0);
+		io_send_sig(SIGPIPE);
 		goto out;
 	}
 
diff --git a/net/netrom/af_netrom.c b/net/netrom/af_netrom.c
index ed212ff..b5eaecc 100644
--- a/net/netrom/af_netrom.c
+++ b/net/netrom/af_netrom.c
@@ -1044,7 +1044,7 @@ static int nr_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
 	}
 
 	if (sk->sk_shutdown & SEND_SHUTDOWN) {
-		send_sig(SIGPIPE, current, 0);
+		io_send_sig(SIGPIPE);
 		err = -EPIPE;
 		goto out;
 	}
diff --git a/net/rose/af_rose.c b/net/rose/af_rose.c
index 129d357..954725c 100644
--- a/net/rose/af_rose.c
+++ b/net/rose/af_rose.c
@@ -1065,7 +1065,7 @@ static int rose_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
 		return -EADDRNOTAVAIL;
 
 	if (sk->sk_shutdown & SEND_SHUTDOWN) {
-		send_sig(SIGPIPE, current, 0);
+		io_send_sig(SIGPIPE);
 		return -EPIPE;
 	}
 
diff --git a/net/sctp/socket.c b/net/sctp/socket.c
index ef1d90f..75bb437 100644
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -1556,7 +1556,7 @@ static int sctp_error(struct sock *sk, int flags, int err)
 	if (err == -EPIPE)
 		err = sock_error(sk) ? : -EPIPE;
 	if (err == -EPIPE && !(flags & MSG_NOSIGNAL))
-		send_sig(SIGPIPE, current, 0);
+		io_send_sig(SIGPIPE);
 	return err;
 }
 
diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
index a4631477..a1d5cf8 100644
--- a/net/unix/af_unix.c
+++ b/net/unix/af_unix.c
@@ -1909,7 +1909,7 @@ pipe_err_free:
 	kfree_skb(skb);
 pipe_err:
 	if (sent == 0 && !(msg->msg_flags&MSG_NOSIGNAL))
-		send_sig(SIGPIPE, current, 0);
+		io_send_sig(SIGPIPE);
 	err = -EPIPE;
 out_err:
 	scm_destroy(&scm);
@@ -2026,7 +2026,7 @@ err_unlock:
 err:
 	kfree_skb(newskb);
 	if (send_sigpipe && !(flags & MSG_NOSIGNAL))
-		send_sig(SIGPIPE, current, 0);
+		io_send_sig(SIGPIPE);
 	if (!init_scm)
 		scm_destroy(&scm);
 	return err;
diff --git a/net/x25/af_x25.c b/net/x25/af_x25.c
index a750f33..102dd03 100644
--- a/net/x25/af_x25.c
+++ b/net/x25/af_x25.c
@@ -1103,7 +1103,7 @@ static int x25_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
 
 	rc = -EPIPE;
 	if (sk->sk_shutdown & SEND_SHUTDOWN) {
-		send_sig(SIGPIPE, current, 0);
+		io_send_sig(SIGPIPE);
 		goto out;
 	}
 
-- 
2.5.0


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