From 955e304f6fc1703edafed69b299a8ca39233f865 Mon Sep 17 00:00:00 2001
From: Luke Shumaker <lukeshu@parabola.nu>
Date: Thu, 28 Dec 2017 13:08:09 -0500
Subject: [PATCH] linux-user: init_guest_commpage: Add a comment about size
check
Signed-off-by: Luke Shumaker <lukeshu@parabola.nu>
Message-Id: <20171228180814.9749-7-lukeshu@lukeshu.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
---
linux-user/elfload.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/linux-user/elfload.c b/linux-user/elfload.c
index 653157876c..8699f430b1 100644
--- a/linux-user/elfload.c
+++ b/linux-user/elfload.c
@@ -374,6 +374,11 @@ static int init_guest_commpage(unsigned long guest_base,
/* If the commpage lies within the already allocated guest space,
* then there is no way we can allocate it.
+ *
+ * You may be thinking that that this check is redundant because
+ * we already validated the guest size against MAX_RESERVED_VA;
+ * but if qemu_host_page_mask is unusually large, then
+ * test_page_addr may be lower.
*/
if (test_page_addr >= guest_base
&& test_page_addr < (guest_base + guest_size)) {
--
2.30.2