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From: Al Viro <viro@ZenIV.linux.org.uk>
To: linux-fsdevel@vger.kernel.org
Subject: [PATCH 2/4] vmsplice(): lift importing iovec into vmsplice(2) and compat counterpart
Date: Mon, 28 May 2018 23:20:11 +0100	[thread overview]
Message-ID: <20180528222013.18402-2-viro@ZenIV.linux.org.uk> (raw)
In-Reply-To: <20180528222013.18402-1-viro@ZenIV.linux.org.uk>

From: Al Viro <viro@zeniv.linux.org.uk>

... getting rid of transformations in the latter - just use
compat_import_iovec().

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 fs/splice.c | 59 ++++++++++++++++++++++++++++-------------------------------
 1 file changed, 28 insertions(+), 31 deletions(-)

diff --git a/fs/splice.c b/fs/splice.c
index 920ff0b20e53..ab224fea4760 100644
--- a/fs/splice.c
+++ b/fs/splice.c
@@ -1310,67 +1310,64 @@ static long vmsplice_to_pipe(struct file *file, struct iov_iter *iter,
  * Currently we punt and implement it as a normal copy, see pipe_to_user().
  *
  */
-static long do_vmsplice(int fd, const struct iovec __user *uiov,
-			unsigned long nr_segs, unsigned int flags)
+static long do_vmsplice(int fd, struct iov_iter *iter, unsigned int flags)
 {
-	struct iovec iovstack[UIO_FASTIOV];
-	struct iovec *iov = iovstack;
-	struct iov_iter iter;
 	struct fd f;
 	long error;
 
 	if (unlikely(flags & ~SPLICE_F_ALL))
 		return -EINVAL;
 
-	error = import_iovec(READ, uiov, nr_segs,
-			   ARRAY_SIZE(iovstack), &iov, &iter);
-	if (error < 0)
-		return error;
-
-	if (!iov_iter_count(&iter)) {
-		kfree(iov);
+	if (!iov_iter_count(iter))
 		return 0;
-	}
 
 	error = -EBADF;
 	f = fdget(fd);
 	if (f.file) {
 		if (f.file->f_mode & FMODE_WRITE)
-			error = vmsplice_to_pipe(f.file, &iter, flags);
+			error = vmsplice_to_pipe(f.file, iter, flags);
 		else if (f.file->f_mode & FMODE_READ)
-			error = vmsplice_to_user(f.file, &iter, flags);
+			error = vmsplice_to_user(f.file, iter, flags);
 
 		fdput(f);
 	}
-	kfree(iov);
 
 	return error;
 }
 
-SYSCALL_DEFINE4(vmsplice, int, fd, const struct iovec __user *, iov,
+SYSCALL_DEFINE4(vmsplice, int, fd, const struct iovec __user *, uiov,
 		unsigned long, nr_segs, unsigned int, flags)
 {
-	return do_vmsplice(fd, iov, nr_segs, flags);
+	struct iovec iovstack[UIO_FASTIOV];
+	struct iovec *iov = iovstack;
+	struct iov_iter iter;
+	long error;
+
+	error = import_iovec(READ, uiov, nr_segs,
+			   ARRAY_SIZE(iovstack), &iov, &iter);
+	if (!error) {
+		error = do_vmsplice(fd, &iter, flags);
+		kfree(iov);
+	}
+	return error;
 }
 
 #ifdef CONFIG_COMPAT
 COMPAT_SYSCALL_DEFINE4(vmsplice, int, fd, const struct compat_iovec __user *, iov32,
 		    unsigned int, nr_segs, unsigned int, flags)
 {
-	unsigned i;
-	struct iovec __user *iov;
-	if (nr_segs > UIO_MAXIOV)
-		return -EINVAL;
-	iov = compat_alloc_user_space(nr_segs * sizeof(struct iovec));
-	for (i = 0; i < nr_segs; i++) {
-		struct compat_iovec v;
-		if (get_user(v.iov_base, &iov32[i].iov_base) ||
-		    get_user(v.iov_len, &iov32[i].iov_len) ||
-		    put_user(compat_ptr(v.iov_base), &iov[i].iov_base) ||
-		    put_user(v.iov_len, &iov[i].iov_len))
-			return -EFAULT;
+	struct iovec iovstack[UIO_FASTIOV];
+	struct iovec *iov = iovstack;
+	struct iov_iter iter;
+	long error;
+
+	error = compat_import_iovec(READ, iov32, nr_segs,
+			   ARRAY_SIZE(iovstack), &iov, &iter);
+	if (!error) {
+		error = do_vmsplice(fd, &iter, flags);
+		kfree(iov);
 	}
-	return do_vmsplice(fd, iov, nr_segs, flags);
+	return error;
 }
 #endif
 
-- 
2.11.0

  reply	other threads:[~2018-05-28 22:20 UTC|newest]

Thread overview: 72+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-05-23 19:19 aio poll and a new in-kernel poll API V13 Christoph Hellwig
2018-05-23 19:19 ` [PATCH 01/33] fix io_destroy()/aio_complete() race Christoph Hellwig
2018-05-23 19:19 ` [PATCH 02/33] uapi: turn __poll_t sparse checkin on by default Christoph Hellwig
2018-05-23 19:19 ` [PATCH 03/33] fs: unexport poll_schedule_timeout Christoph Hellwig
2018-05-23 19:19 ` [PATCH 04/33] fs: cleanup do_pollfd Christoph Hellwig
2018-05-23 19:19 ` [PATCH 05/33] fs: update documentation to mention __poll_t and match the code Christoph Hellwig
2018-05-23 19:19 ` [PATCH 06/33] fs: add new vfs_poll and file_can_poll helpers Christoph Hellwig
2018-05-23 19:19 ` [PATCH 07/33] fs: introduce new ->get_poll_head and ->poll_mask methods Christoph Hellwig
2018-05-23 19:19 ` [PATCH 08/33] aio: simplify KIOCB_KEY handling Christoph Hellwig
2018-05-23 19:19 ` [PATCH 09/33] aio: simplify cancellation Christoph Hellwig
2018-05-23 19:19 ` [PATCH 10/33] aio: implement IOCB_CMD_POLL Christoph Hellwig
2018-05-23 19:20 ` [PATCH 11/33] aio: try to complete poll iocbs without context switch Christoph Hellwig
2018-05-23 19:20 ` [PATCH 12/33] net: refactor socket_poll Christoph Hellwig
2018-05-23 19:20 ` [PATCH 13/33] net: add support for ->poll_mask in proto_ops Christoph Hellwig
2018-05-23 19:20 ` [PATCH 14/33] net: remove sock_no_poll Christoph Hellwig
2018-05-23 19:20 ` [PATCH 15/33] net/tcp: convert to ->poll_mask Christoph Hellwig
2018-05-23 19:20 ` [PATCH 16/33] net/unix: " Christoph Hellwig
2018-05-23 19:20 ` [PATCH 17/33] net: convert datagram_poll users tp ->poll_mask Christoph Hellwig
2018-05-23 19:20 ` [PATCH 18/33] net/dccp: convert to ->poll_mask Christoph Hellwig
2018-05-23 19:20 ` [PATCH 19/33] net/atm: " Christoph Hellwig
2018-05-23 19:20 ` [PATCH 20/33] net/vmw_vsock: " Christoph Hellwig
2018-05-23 19:20 ` [PATCH 21/33] net/tipc: " Christoph Hellwig
2018-05-23 19:20 ` [PATCH 22/33] net/sctp: " Christoph Hellwig
2018-05-23 19:20 ` [PATCH 23/33] net/bluetooth: " Christoph Hellwig
2018-05-23 19:20 ` [PATCH 24/33] net/caif: " Christoph Hellwig
2018-05-23 19:20 ` [PATCH 25/33] net/nfc: " Christoph Hellwig
2018-05-23 19:20 ` [PATCH 26/33] net/phonet: " Christoph Hellwig
2018-05-23 19:20 ` [PATCH 27/33] net/iucv: " Christoph Hellwig
2018-05-23 19:20 ` [PATCH 28/33] net/rxrpc: " Christoph Hellwig
2018-05-23 19:20 ` [PATCH 29/33] crypto: af_alg: " Christoph Hellwig
2018-05-23 19:20 ` [PATCH 30/33] pipe: " Christoph Hellwig
2018-05-23 19:20 ` [PATCH 31/33] eventfd: switch " Christoph Hellwig
2018-05-23 19:20 ` [PATCH 32/33] timerfd: convert " Christoph Hellwig
2018-05-23 19:20 ` [PATCH 33/33] random: " Christoph Hellwig
2018-05-26  0:11 ` aio poll and a new in-kernel poll API V13 Al Viro
2018-05-26  7:09   ` Al Viro
2018-05-26  7:23     ` Christoph Hellwig
2018-05-27 22:27       ` Al Viro
2018-05-27 22:28         ` [PATCH 1/4] aio: all callers of aio_{read,write,fsync,poll} treat 0 and -EIOCBQUEUED the same way Al Viro
2018-05-27 22:28           ` [PATCH 2/4] aio_read_events_ring(): make a bit more readable Al Viro
2018-05-27 22:28           ` [PATCH 3/4] aio: shift copyin of iocb into io_submit_one() Al Viro
2018-05-28  5:16             ` Christoph Hellwig
2018-05-27 22:28           ` [PATCH 4/4] aio: fold do_io_submit() into callers Al Viro
2018-05-27 23:14             ` Al Viro
2018-05-28  5:24               ` Christoph Hellwig
2018-05-28  5:15           ` [PATCH 1/4] aio: all callers of aio_{read,write,fsync,poll} treat 0 and -EIOCBQUEUED the same way Christoph Hellwig
2018-05-28 14:04             ` Al Viro
2018-05-28 17:54               ` Al Viro
2018-05-28 17:57                 ` [PATCH v2 1/6] aio: take list removal to (some) callers of aio_complete() Al Viro
2018-05-28 17:57                   ` [PATCH v2 2/6] aio: all callers of aio_{read,write,fsync,poll} treat 0 and -EIOCBQUEUED the same way Al Viro
2018-05-29  6:08                     ` Christoph Hellwig
2018-05-28 17:57                   ` [PATCH v2 3/6] aio_read_events_ring(): make a bit more readable Al Viro
2018-05-28 17:57                   ` [PATCH v2 4/6] aio: shift copyin of iocb into io_submit_one() Al Viro
2018-05-28 17:57                   ` [PATCH v2 5/6] aio: fold do_io_submit() into callers Al Viro
2018-05-29  6:10                     ` Christoph Hellwig
2018-05-28 17:57                   ` [PATCH v2 6/6] aio: sanitize the limit checking in io_submit(2) Al Viro
2018-05-29  6:10                     ` Christoph Hellwig
2018-05-29  6:08                   ` [PATCH v2 1/6] aio: take list removal to (some) callers of aio_complete() Christoph Hellwig
2018-05-28 22:20                 ` [PATCH 1/4] vmsplice: lift import_iovec() into do_vmsplice() Al Viro
2018-05-28 22:20                   ` Al Viro [this message]
2018-05-28 22:20                   ` [PATCH 3/4] signalfd: lift sigmask copyin and size checks to callers of do_signalfd4() Al Viro
2018-05-28 22:20                   ` [PATCH 4/4] orangefs: simplify compat ioctl handling Al Viro
2018-05-31 11:11                     ` kbuild test robot
2018-05-31 20:54                     ` Mike Marshall
2018-05-31 21:03                       ` Al Viro
2018-06-01 21:13                         ` Mike Marshall
2018-06-06 22:57                   ` [1/4] vmsplice: lift import_iovec() into do_vmsplice() Andrei Vagin
2018-06-07 17:56                     ` Andrei Vagin
2018-06-11 20:14                       ` Cyrill Gorcunov
2018-06-11 20:16                         ` Al Viro
2018-06-11 20:18                           ` Cyrill Gorcunov
2018-06-14 22:22                           ` Andrey Vagin

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