From afd2eb53449df925a863211af9d7a9cae56d88a2 Mon Sep 17 00:00:00 2001
From: Robert Norton
Date: Tue, 6 Mar 2018 16:31:09 +0000
Subject: Check tag of pcc in TranslatePC. This could happen after an ERET with
 untagged EPCC. ISA says this results in undefined behaviour but it should
 probably not permit execution of code with untagged PCC.

---
 cheri/cheri_prelude_common.sail | 2 ++
 1 file changed, 2 insertions(+)

(limited to 'cheri')

diff --git a/cheri/cheri_prelude_common.sail b/cheri/cheri_prelude_common.sail
index 0a491145..5dd14974 100644
--- a/cheri/cheri_prelude_common.sail
+++ b/cheri/cheri_prelude_common.sail
@@ -369,6 +369,8 @@ function TranslatePC (vAddr) = {
   let absPC = base + unsigned(vAddr);
   if ((absPC % 4)  != 0) then /* bad PC alignment */
     (SignalExceptionBadAddr(AdEL, to_bits(64, absPC))) /* XXX absPC may be truncated */
+  else if not (pcc.tag) then
+    (raise_c2_exception_noreg(CapEx_TagViolation))
   else if ((absPC + 4) > top) then
     (raise_c2_exception_noreg(CapEx_LengthViolation))
   else
-- 
cgit v1.2.3