From: Keir Fraser <keir.fraser@citrix.com>
Date: Fri, 26 Mar 2010 08:48:08 +0000 (+0000)
Subject: shadow: Don't crash xen if hvm_read() from paged or shared memory
X-Git-Tag: archive/raspbian/4.8.0-1+rpi1~1^2~12472
X-Git-Url: https://dgit.raspbian.org/%22http://www.example.com/cgi/success//%22http:/www.example.com/cgi/success/?a=commitdiff_plain;h=b8352255b3eac73ab2f15874575613603aa2e9c0;p=xen.git

shadow: Don't crash xen if hvm_read() from paged or shared memory

There are two new return cases from hvm_copy_from_guest_virt() to deal
with paging or shared memory -- retry the emulation rather than
crash.

Signed-off-by: Steven Hand <steven.hand@cl.cam.ac.uk>
---

diff --git a/xen/arch/x86/mm/shadow/common.c b/xen/arch/x86/mm/shadow/common.c
index 5e37bb01d4..36f92760cf 100644
--- a/xen/arch/x86/mm/shadow/common.c
+++ b/xen/arch/x86/mm/shadow/common.c
@@ -180,6 +180,9 @@ hvm_read(enum x86_segment seg,
     case HVMCOPY_bad_gfn_to_mfn:
     case HVMCOPY_unhandleable:
         return X86EMUL_UNHANDLEABLE;
+    case HVMCOPY_gfn_paged_out:
+    case HVMCOPY_gfn_shared:
+        return X86EMUL_RETRY;
     }
 
     BUG();