From: Pavel Begunkov <asml.silence@gmail.com>
To: io-uring@vger.kernel.org
Cc: asml.silence@gmail.com, Anuj gupta <anuj1072538@gmail.com>,
	Jens Axboe <axboe@kernel.dk>
Subject: [PATCH v2 4/6] io_uring/rw: shrink io_iov_compat_buffer_select_prep
Date: Mon, 24 Feb 2025 12:42:22 +0000	[thread overview]
Message-ID: <b334a3a5040efa424ded58e4d8a6ef2554324266.1740400452.git.asml.silence@gmail.com> (raw)
In-Reply-To: <cover.1740400452.git.asml.silence@gmail.com>

Compat performance is not important and simplicity is more appreciated.
Let's not be smart about it and use simpler copy_from_user() instead of
access + __get_user pair.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
---
 io_uring/rw.c | 14 ++++----------
 1 file changed, 4 insertions(+), 10 deletions(-)

diff --git a/io_uring/rw.c b/io_uring/rw.c
index 7133029b4396..22612a956e75 100644
--- a/io_uring/rw.c
+++ b/io_uring/rw.c
@@ -48,18 +48,12 @@ static bool io_file_supports_nowait(struct io_kiocb *req, __poll_t mask)
 
 static int io_iov_compat_buffer_select_prep(struct io_rw *rw)
 {
-	struct compat_iovec __user *uiov;
-	compat_ssize_t clen;
+	struct compat_iovec __user *uiov = u64_to_user_ptr(rw->addr);
+	struct compat_iovec iov;
 
-	uiov = u64_to_user_ptr(rw->addr);
-	if (!access_ok(uiov, sizeof(*uiov)))
-		return -EFAULT;
-	if (__get_user(clen, &uiov->iov_len))
+	if (copy_from_user(&iov, uiov, sizeof(iov)))
 		return -EFAULT;
-	if (clen < 0)
-		return -EINVAL;
-
-	rw->len = clen;
+	rw->len = iov.iov_len;
 	return 0;
 }
 
-- 
2.48.1

next prev parent reply	other threads:[~2025-02-24 12:41 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-02-24 12:42 [PATCH v2 0/6] compile out ctx->compat reads Pavel Begunkov
2025-02-24 12:42 ` [PATCH v2 1/6] io_uring: introduce io_is_compat() Pavel Begunkov
2025-02-24 13:20   ` Anuj gupta
2025-02-24 12:42 ` [PATCH v2 2/6] io_uring/cmd: optimise !CONFIG_COMPAT flags setting Pavel Begunkov
2025-02-24 13:21   ` Anuj gupta
2025-02-24 12:42 ` [PATCH v2 3/6] io_uring/rw: compile out compat param passing Pavel Begunkov
2025-02-24 13:22   ` Anuj gupta
2025-02-24 12:42 ` Pavel Begunkov [this message]
2025-02-24 12:42 ` [PATCH v2 5/6] io_uring/waitid: use io_is_compat() Pavel Begunkov
2025-02-24 13:23   ` Anuj gupta
2025-02-24 15:33   ` Caleb Sander Mateos
2025-02-24 16:12     ` Pavel Begunkov
2025-02-24 12:42 ` [PATCH v2 6/6] io_uring/net: " Pavel Begunkov
2025-02-24 13:23   ` Anuj gupta
2025-02-24 14:35 ` [PATCH v2 0/6] compile out ctx->compat reads Jens Axboe

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