From: Jan Beulich <jbeulich@suse.com>
Date: Wed, 3 Apr 2019 08:14:32 +0000 (+0200)
Subject: x86emul: suppress general register update upon AVX gather failures
X-Git-Tag: archive/raspbian/4.14.0+80-gd101b417b7-1+rpi1^2~63^2~2417
X-Git-Url: https://dgit.raspbian.org/?a=commitdiff_plain;h=74f299bbd7d5cc52325b5866c17b44dd0bd1c5a2;p=xen.git

x86emul: suppress general register update upon AVX gather failures

While destination and mask registers may indeed need updating in this
case, the rIP update in particular needs to be avoided, as well as e.g.
raising a single step trap.

Reported-by: George Dunlap <george.dunlap@citrix.com>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
---

diff --git a/xen/arch/x86/x86_emulate/x86_emulate.c b/xen/arch/x86/x86_emulate/x86_emulate.c
index ea02d100dd..0293a72292 100644
--- a/xen/arch/x86/x86_emulate/x86_emulate.c
+++ b/xen/arch/x86/x86_emulate/x86_emulate.c
@@ -8547,6 +8547,9 @@ x86_emulate(
         invoke_stub("", "", "+m" (mask) : "a" (&mask));
         put_stub(stub);
 
+        if ( rc != X86EMUL_OKAY )
+            goto done;
+
         state->simd_size = simd_none;
         break;
     }