From: Andrew Cooper <andrew.cooper3@citrix.com>
Date: Fri, 15 Sep 2023 15:10:58 +0000 (+0100)
Subject: x86/emul: ASSERT that X86EMUL_DONE doesn't escape to callers
X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=f6b0a80a36766e759a8a49c3556c1f03279978e4;p=people%2Froyger%2Fxen.git

x86/emul: ASSERT that X86EMUL_DONE doesn't escape to callers

This property is far from clear.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
---

diff --git a/xen/arch/x86/x86_emulate/x86_emulate.c b/xen/arch/x86/x86_emulate/x86_emulate.c
index e88245eae9..94caec1d14 100644
--- a/xen/arch/x86/x86_emulate/x86_emulate.c
+++ b/xen/arch/x86/x86_emulate/x86_emulate.c
@@ -8651,6 +8651,12 @@ int x86_emulate_wrapper(
 
     rc = x86_emulate(ctxt, ops);
 
+    /*
+     * X86EMUL_DONE is an internal signal in the emulator, and is not expected
+     * to ever escape out to callers.
+     */
+    ASSERT(rc != X86EMUL_DONE);
+
     /*
      * Most retire flags should only be set for successful instruction
      * emulation.