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From: Alexey Izbyshev <izbyshev@ispras.ru>
To: Jens Axboe <axboe@kernel.dk>,
	Pavel Begunkov <asml.silence@gmail.com>,
	Olivier Langlois <olivier@trillion01.com>
Cc: io-uring@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: [PATCH] io_uring: Fix io_cqring_wait() not restoring sigmask on get_timespec64() failure
Date: Fri,  5 Apr 2024 15:55:51 +0300
Message-ID: <20240405125551.237142-1-izbyshev@ispras.ru>
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This bug was introduced in commit 950e79dd7313 ("io_uring: minor
io_cqring_wait() optimization"), which was made in preparation for
adc8682ec690 ("io_uring: Add support for napi_busy_poll"). The latter
got reverted in cb3182167325 ("Revert "io_uring: Add support for
napi_busy_poll""), so simply undo the former as well.

Fixes: 950e79dd7313 ("io_uring: minor io_cqring_wait() optimization")
Signed-off-by: Alexey Izbyshev <izbyshev@ispras.ru>
---
 io_uring/io_uring.c | 26 +++++++++++++-------------
 1 file changed, 13 insertions(+), 13 deletions(-)

diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c
index cd9a137ad6ce..b764a18f3a49 100644
--- a/io_uring/io_uring.c
+++ b/io_uring/io_uring.c
@@ -2595,19 +2595,6 @@ static int io_cqring_wait(struct io_ring_ctx *ctx, int min_events,
 	if (__io_cqring_events_user(ctx) >= min_events)
 		return 0;
 
-	if (sig) {
-#ifdef CONFIG_COMPAT
-		if (in_compat_syscall())
-			ret = set_compat_user_sigmask((const compat_sigset_t __user *)sig,
-						      sigsz);
-		else
-#endif
-			ret = set_user_sigmask(sig, sigsz);
-
-		if (ret)
-			return ret;
-	}
-
 	init_waitqueue_func_entry(&iowq.wq, io_wake_function);
 	iowq.wq.private = current;
 	INIT_LIST_HEAD(&iowq.wq.entry);
@@ -2624,6 +2611,19 @@ static int io_cqring_wait(struct io_ring_ctx *ctx, int min_events,
 		iowq.timeout = ktime_add_ns(timespec64_to_ktime(ts), ktime_get_ns());
 	}
 
+	if (sig) {
+#ifdef CONFIG_COMPAT
+		if (in_compat_syscall())
+			ret = set_compat_user_sigmask((const compat_sigset_t __user *)sig,
+						      sigsz);
+		else
+#endif
+			ret = set_user_sigmask(sig, sigsz);
+
+		if (ret)
+			return ret;
+	}
+
 	trace_io_uring_cqring_wait(ctx, min_events);
 	do {
 		unsigned long check_cq;
-- 
2.44.0