From 945001a1af36eafd093b6b1582f5282932cd3d87 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Marc-Andr=C3=A9=20Lureau?= <marcandre.lureau@redhat.com>
Date: Tue, 23 Jun 2015 12:55:41 +0200
Subject: [PATCH] ivshmem: check shm isn't already initialized
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The server should not change the shm, and this isn't handled by qemu and
we should should verify this in qemu.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Claudio Fontana <claudio.fontana@huawei.com>
---
 hw/misc/ivshmem.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/hw/misc/ivshmem.c b/hw/misc/ivshmem.c
index d3d02048cd..9023f95711 100644
--- a/hw/misc/ivshmem.c
+++ b/hw/misc/ivshmem.c
@@ -533,6 +533,12 @@ static void ivshmem_read(void *opaque, const uint8_t *buf, int size)
     if (incoming_posn == -1) {
         void * map_ptr;
 
+        if (s->shm_fd >= 0) {
+            error_report("shm already initialized");
+            close(incoming_fd);
+            return;
+        }
+
         if (check_shm_size(s, incoming_fd, &err) == -1) {
             error_report_err(err);
             close(incoming_fd);