From: Andres Lagar-Cavilla <andreslc@google.com>
Date: Thu, 25 Sep 2014 22:26:50 +0000 (-0700)
Subject: kvm: Fix kvm_get_page_retry_io __gup retval check
X-Git-Tag: v3.18-rc1~138^2~4
X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=commitdiff_plain;h=bb0ca6acd466af55c95b7ce508f29e23a24cabd9;p=linux.git

kvm: Fix kvm_get_page_retry_io __gup retval check

Confusion around -EBUSY and zero (inside a BUG_ON no less).

Reported-by: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Andres Lagar-Cavilla <andreslc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---

diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 3f16f569169e..a1cf53ee0d28 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -1146,7 +1146,7 @@ int kvm_get_user_page_io(struct task_struct *tsk, struct mm_struct *mm,
 	npages = __get_user_pages(tsk, mm, addr, 1, flags, pagep, NULL,
 				  &locked);
 	if (!locked) {
-		VM_BUG_ON(npages != -EBUSY);
+		VM_BUG_ON(npages);
 
 		if (!pagep)
 			return 0;