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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org,
        Anton Ivanov <anton.ivanov@cambridgegreys.com>,
        Richard Weinberger <richard@nod.at>
Subject: [PATCH 5.16 1002/1017] um: Fix uml_mconsole stop/go
Date:   Tue,  5 Apr 2022 09:31:55 +0200
Message-Id: <20220405070423.943692936@linuxfoundation.org>
In-Reply-To: <20220405070354.155796697@linuxfoundation.org>
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From: Anton Ivanov <anton.ivanov@cambridgegreys.com>

commit 1a3a6a2a035bb6c3a7ef4c788d8fd69a7b2d6284 upstream.

Moving to an EPOLL based IRQ controller broke uml_mconsole stop/go
commands. This fixes it and restores stop/go functionality.

Fixes: ff6a17989c08 ("Epoll based IRQ controller")
Signed-off-by: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 arch/um/drivers/mconsole_kern.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

--- a/arch/um/drivers/mconsole_kern.c
+++ b/arch/um/drivers/mconsole_kern.c
@@ -224,7 +224,7 @@ void mconsole_go(struct mc_request *req)
 
 void mconsole_stop(struct mc_request *req)
 {
-	deactivate_fd(req->originating_fd, MCONSOLE_IRQ);
+	block_signals();
 	os_set_fd_block(req->originating_fd, 1);
 	mconsole_reply(req, "stopped", 0, 0);
 	for (;;) {
@@ -247,6 +247,7 @@ void mconsole_stop(struct mc_request *re
 	}
 	os_set_fd_block(req->originating_fd, 0);
 	mconsole_reply(req, "", 0, 0);
+	unblock_signals();
 }
 
 static DEFINE_SPINLOCK(mc_devices_lock);