linux-kernel - [PATCH] KVM: squelch uninitialized variable warning

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Message-Id: <20200109195855.17353-1-brho@google.com>
Date:   Thu,  9 Jan 2020 14:58:55 -0500
From:   Barret Rhoden <brho@...gle.com>
To:     pbonzini@...hat.com
Cc:     kvm@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: [PATCH] KVM: squelch uninitialized variable warning

If gfn_to_hva_many() fails, __kvm_gfn_to_hva_cache_init() will return an
error.  Before it does, it might use nr_pages_avail, which my compiler
complained about:

	virt/kvm/kvm_main.c:2193:13: warning: 'nr_pages_avail' may be
	used uninitialized in this function [-Wmaybe-uninitialized]

	   start_gfn += nr_pages_avail;

Signed-off-by: Barret Rhoden <brho@...gle.com>
---
 virt/kvm/kvm_main.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index d9aced677ddd..f8249b153d33 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -2172,7 +2172,7 @@ static int __kvm_gfn_to_hva_cache_init(struct kvm_memslots *slots,
 	gfn_t start_gfn = gpa >> PAGE_SHIFT;
 	gfn_t end_gfn = (gpa + len - 1) >> PAGE_SHIFT;
 	gfn_t nr_pages_needed = end_gfn - start_gfn + 1;
-	gfn_t nr_pages_avail;
+	gfn_t nr_pages_avail = 0;
 	int r = start_gfn <= end_gfn ? 0 : -EINVAL;
 
 	ghc->gpa = gpa;
-- 
2.25.0.rc1.283.g88dfdc4193-goog