[PATCH] io_uring: use __kernel_timespec in timeout ABI

From: Arnd Bergmann <arnd@arndb.de>
To: Jens Axboe <axboe@kernel.dk>
Cc: "Hannes Reinecke" <hare@suse.com>,
	"Arnd Bergmann" <arnd@arndb.de>,
	y2038@lists.linaro.org, linux-api@vger.kernel.org,
	"Jackie Liu" <liuyun01@kylinos.cn>,
	linux-kernel@vger.kernel.org, linux-block@vger.kernel.org,
	"Stefan Bühler" <source@stbuehler.de>,
	"Alexander Viro" <viro@zeniv.linux.org.uk>,
	linux-fsdevel@vger.kernel.org,
	"Andrew Morton" <akpm@linux-foundation.org>,
	"Hristo Venev" <hristo@venev.name>
Subject: [PATCH] io_uring: use __kernel_timespec in timeout ABI
Date: Mon, 30 Sep 2019 22:20:39 +0200	[thread overview]
Message-ID: <20190930202055.1748710-1-arnd@arndb.de> (raw)

All system calls use struct __kernel_timespec instead of the old struct
timespec, but this one was just added with the old-style ABI. Change it
now to enforce the use of __kernel_timespec, avoiding ABI confusion and
the need for compat handlers on 32-bit architectures.

Any user space caller will have to use __kernel_timespec now, but this
is unambiguous and works for any C library regardless of the time_t
definition. A nicer way to specify the timeout would have been a less
ambiguous 64-bit nanosecond value, but I suppose it's too late now to
change that as this would impact both 32-bit and 64-bit users.

Fixes: 5262f567987d ("io_uring: IORING_OP_TIMEOUT support")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 fs/io_uring.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/fs/io_uring.c b/fs/io_uring.c
index aa8ac557493c..8a0381f1a43b 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -1892,15 +1892,15 @@ static int io_timeout(struct io_kiocb *req, const struct io_uring_sqe *sqe)
 	unsigned count, req_dist, tail_index;
 	struct io_ring_ctx *ctx = req->ctx;
 	struct list_head *entry;
-	struct timespec ts;
+	struct timespec64 ts;
 
 	if (unlikely(ctx->flags & IORING_SETUP_IOPOLL))
 		return -EINVAL;
 	if (sqe->flags || sqe->ioprio || sqe->buf_index || sqe->timeout_flags ||
 	    sqe->len != 1)
 		return -EINVAL;
-	if (copy_from_user(&ts, (void __user *) (unsigned long) sqe->addr,
-	    sizeof(ts)))
+
+	if (get_timespec64(&ts, u64_to_user_ptr(sqe->addr)))
 		return -EFAULT;
 
 	/*
@@ -1934,7 +1934,7 @@ static int io_timeout(struct io_kiocb *req, const struct io_uring_sqe *sqe)
 
 	hrtimer_init(&req->timeout.timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
 	req->timeout.timer.function = io_timeout_fn;
-	hrtimer_start(&req->timeout.timer, timespec_to_ktime(ts),
+	hrtimer_start(&req->timeout.timer, timespec64_to_ktime(ts),
 			HRTIMER_MODE_REL);
 	return 0;
 }
-- 
2.20.0

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