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From: "Michael S. Tsirkin" <mst@redhat.com>
To: Rusty Russell <rusty@rustcorp.com.au>,
	kvm@vger.kernel.org, virtualization@lists.osdl.org,
	netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
	David Miller <davem@davemloft.net>,
	ma
Subject: [PATCH 3/3] vhost: fix get_user_pages_fast error handling
Date: Tue, 23 Feb 2010 18:57:58 +0200	[thread overview]
Message-ID: <82ba8c97ce55dd4bf9972ad755961cd14e6a0938.1266943453.git.mst@redhat.com> (raw)
In-Reply-To: <cover.1266943453.git.mst@redhat.com>

get_user_pages_fast returns number of pages on success, negative value
on failure, but never 0. Fix vhost code to match this logic.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
 drivers/vhost/vhost.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index d4f8fdf..d003504 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -646,8 +646,9 @@ static int set_bit_to_user(int nr, void __user *addr)
 	int bit = nr + (log % PAGE_SIZE) * 8;
 	int r;
 	r = get_user_pages_fast(log, 1, 1, &page);
-	if (r)
+	if (r < 0)
 		return r;
+	BUG_ON(r != 1);
 	base = kmap_atomic(page, KM_USER0);
 	set_bit(bit, base);
 	kunmap_atomic(base, KM_USER0);
-- 
1.7.0.18.g0d53a5

  parent reply	other threads:[~2010-02-23 16:57 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-02-23 16:57 [PATCH 0/3] vhost: logging fixes Michael S. Tsirkin
2010-02-23 16:57 ` [PATCH 1/3] vhost: logging math fix Michael S. Tsirkin
2010-02-23 19:26   ` Juan Quintela
2010-02-23 16:57 ` [PATCH 2/3] vhost: initialize log eventfd context pointer Michael S. Tsirkin
2010-02-23 19:31   ` Juan Quintela
2010-02-23 16:57 ` Michael S. Tsirkin [this message]
2010-02-23 17:34   ` [PATCH 3/3] vhost: fix get_user_pages_fast error handling Gleb Natapov
2010-02-23 17:32     ` Michael S. Tsirkin
2010-02-23 17:39       ` Gleb Natapov
2010-02-23 17:39         ` Michael S. Tsirkin
2010-02-23 17:43           ` Gleb Natapov
2010-02-23 22:42         ` David Miller
2010-02-24  5:37           ` Michael S. Tsirkin
2010-02-24  7:04             ` David Miller
2010-02-24  7:34               ` Michael S. Tsirkin
2010-02-24  7:41                 ` David Miller
2010-02-23 19:56   ` Juan Quintela

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