From: Roger Pau Monné <roger.pau@citrix.com>
Date: Mon, 25 Nov 2019 15:20:17 +0000 (+0100)
Subject: x86/shim: copy back the result of EVTCHNOP_status
X-Git-Tag: archive/raspbian/4.11.3+24-g14b62ab3e5-1+rpi1^2~55^2~35
X-Git-Url: https://dgit.raspbian.org/?a=commitdiff_plain;h=0a79df73307076b0e946fd8fb87e8fbaca15d596;p=xen.git

x86/shim: copy back the result of EVTCHNOP_status

The event channel data was not copied back to guest memory, fix this
by doing the copy.

Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Wei Liu <wl@xen.org>
master commit: 0f45bbbc404e2d1257476f9caa6644c209ec2c90
master date: 2019-11-01 10:48:04 +0000
---

diff --git a/xen/arch/x86/pv/shim.c b/xen/arch/x86/pv/shim.c
index 1299112ce0..d4146fe234 100644
--- a/xen/arch/x86/pv/shim.c
+++ b/xen/arch/x86/pv/shim.c
@@ -470,6 +470,9 @@ static long pv_shim_event_channel_op(int cmd, XEN_GUEST_HANDLE_PARAM(void) arg)
         else
             rc = xen_hypercall_event_channel_op(EVTCHNOP_status, &status);
 
+        if ( !rc && __copy_to_guest(arg, &status, 1) )
+            rc = -EFAULT;
+
         break;
     }