From 3fc4a64cbaed2ddee4c60ddc06740b320e18ab82 Mon Sep 17 00:00:00 2001 From: "Dr. David Alan Gilbert" Date: Wed, 14 Aug 2019 18:55:35 +0100 Subject: [PATCH] vhost: Fix memory region section comparison Using memcmp to compare structures wasn't safe, as I found out on ARM when I was getting falce miscompares. Use the helper function for comparing the MRSs. Fixes: ade6d081fc33948e56e6 ("vhost: Regenerate region list from changed sections list") Cc: qemu-stable@nongnu.org Signed-off-by: Dr. David Alan Gilbert Message-Id: <20190814175535.2023-4-dgilbert@redhat.com> Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin --- hw/virtio/vhost.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c index 34accdf6153d..2386b511f311 100644 --- a/hw/virtio/vhost.c +++ b/hw/virtio/vhost.c @@ -451,8 +451,13 @@ static void vhost_commit(MemoryListener *listener) changed = true; } else { /* Same size, lets check the contents */ - changed = n_old_sections && memcmp(dev->mem_sections, old_sections, - n_old_sections * sizeof(old_sections[0])) != 0; + for (int i = 0; i < n_old_sections; i++) { + if (!MemoryRegionSection_eq(&old_sections[i], + &dev->mem_sections[i])) { + changed = true; + break; + } + } } trace_vhost_commit(dev->started, changed);