From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:58124) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZubzK-0000p7-B2 for qemu-devel@nongnu.org; Fri, 06 Nov 2015 03:03:11 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ZubzH-00007L-1j for qemu-devel@nongnu.org; Fri, 06 Nov 2015 03:03:10 -0500 Received: from mx1.redhat.com ([209.132.183.28]:56883) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZubzG-00007G-U8 for qemu-devel@nongnu.org; Fri, 06 Nov 2015 03:03:07 -0500 From: Jason Wang Date: Fri, 6 Nov 2015 16:02:45 +0800 Message-Id: <1446796969-8049-3-git-send-email-jasowang@redhat.com> In-Reply-To: <1446796969-8049-1-git-send-email-jasowang@redhat.com> References: <1446796969-8049-1-git-send-email-jasowang@redhat.com> Subject: [Qemu-devel] [PATCH V3 2/6] memory: don't try to adjust endianness for zero length eventfd List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: mst@redhat.com, qemu-devel@nongnu.org Cc: cornelia.huck@de.ibm.com, Peter Maydell , Jason Wang , Paolo Bonzini , Greg Kurz There's no need to adjust endianness for zero length eventfd since the data wrote was actually ignored by kernel. So skip the adjust in this case to fix a possible crash when trying to use wildcard mmio eventfd in ppc. Cc: Greg Kurz Cc: Peter Maydell Cc: Paolo Bonzini Acked-by: Greg Kurz Signed-off-by: Jason Wang --- memory.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/memory.c b/memory.c index c435c88..e193658 100644 --- a/memory.c +++ b/memory.c @@ -1688,7 +1688,9 @@ void memory_region_add_eventfd(MemoryRegion *mr, }; unsigned i; - adjust_endianness(mr, &mrfd.data, size); + if (size) { + adjust_endianness(mr, &mrfd.data, size); + } memory_region_transaction_begin(); for (i = 0; i < mr->ioeventfd_nb; ++i) { if (memory_region_ioeventfd_before(mrfd, mr->ioeventfds[i])) { @@ -1721,7 +1723,9 @@ void memory_region_del_eventfd(MemoryRegion *mr, }; unsigned i; - adjust_endianness(mr, &mrfd.data, size); + if (size) { + adjust_endianness(mr, &mrfd.data, size); + } memory_region_transaction_begin(); for (i = 0; i < mr->ioeventfd_nb; ++i) { if (memory_region_ioeventfd_equal(mrfd, mr->ioeventfds[i])) { -- 2.1.4