From 46415e245ed90b1bb08ff4d67559a6c0f34cf9db Mon Sep 17 00:00:00 2001
From: Jeffrey Cody <jcody@redhat.com>
Date: Wed, 29 Jul 2015 16:59:53 +0200
Subject: [PATCH 02/13] vpc: Handle failure for potentially large allocations

Message-id: <e1f23ed0869898acec75825bec74cf375bee876b.1438188988.git.jcody@redhat.com>
Patchwork-id: 67196
O-Subject: [RHEL-7.2 qemu-kvm PATCH 1/3] vpc: Handle failure for potentially large allocations
Bugzilla: 1217349
RH-Acked-by: Laszlo Ersek <lersek@redhat.com>
RH-Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
RH-Acked-by: Max Reitz <mreitz@redhat.com>

From: Kevin Wolf <kwolf@redhat.com>

Some code in the block layer makes potentially huge allocations. Failure
is not completely unexpected there, so avoid aborting qemu and handle
out-of-memory situations gracefully.

This patch addresses the allocations in the vpc block driver.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Benoit Canet <benoit@irqsave.net>
(cherry picked from commit 5fb09cd5867aabf26d5b85b0913dccd496b71421)
Signed-off-by: Jeff Cody <jcody@redhat.com>
Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>
---
 block/vpc.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/block/vpc.c b/block/vpc.c
index 849501a..6fdce40 100644
--- a/block/vpc.c
+++ b/block/vpc.c
@@ -260,7 +260,11 @@ static int vpc_open(BlockDriverState *bs, QDict *options, int flags,
             goto fail;
         }
 
-        s->pagetable = qemu_blockalign(bs, s->max_table_entries * 4);
+        s->pagetable = qemu_try_blockalign(bs->file, s->max_table_entries * 4);
+        if (s->pagetable == NULL) {
+            ret = -ENOMEM;
+            goto fail;
+        }
 
         s->bat_offset = be64_to_cpu(dyndisk_header->table_offset);
 
-- 
1.8.3.1