mem: Add invalid context id check on LLSC checks

If the request's address is in the LLSC list, its context Id was being
fetched unconditionally, which could cause the assert at
Request::contextId() to fail.

Change-Id: Iae9791f81c8fe9a7fcd842cd8ab7db18f34f2808
Signed-off-by: Tiago Muck <tiago.muck@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/18792
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>

diff --git a/src/mem/abstract_mem.cc b/src/mem/abstract_mem.cc
index a998530fdfe7c7c0b05b59c9308521e96b5b0ecb..6870ba38fc0d96536b964bb61c1ff7736c787424 100644 (file)
--- a/src/mem/abstract_mem.cc
+++ b/src/mem/abstract_mem.cc
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2010-2012,2017-2018 ARM Limited
+ * Copyright (c) 2010-2012,2017-2019 ARM Limited
  * All rights reserved
  *
  * The license below extends only to copyright in the software and shall
@@ -284,7 +284,10 @@ AbstractMemory::checkLockedAddrList(PacketPtr pkt)
                 DPRINTF(LLSC, "Erasing lock record: context %d addr %#x\n",
                         i->contextId, paddr);
                 ContextID owner_cid = i->contextId;
-                ContextID requester_cid = pkt->req->contextId();
+                assert(owner_cid != InvalidContextID);
+                ContextID requester_cid = req->hasContextId() ?
+                                           req->contextId() :
+                                           InvalidContextID;
                 if (owner_cid != requester_cid) {
                     ThreadContext* ctx = system()->getThreadContext(owner_cid);
                     TheISA::globalClearExclusive(ctx);

diff --git a/src/mem/abstract_mem.hh b/src/mem/abstract_mem.hh
index 18d8ee9098bf03eb31ab64e2bc7b0d39495d4336..8b944b9815e58b9ca21ff894be4a34397310bb71 100644 (file)
--- a/src/mem/abstract_mem.hh
+++ b/src/mem/abstract_mem.hh
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2012 ARM Limited
+ * Copyright (c) 2012, 2019 ARM Limited
  * All rights reserved
  *
  * The license below extends only to copyright in the software and shall
@@ -83,6 +83,8 @@ class LockedAddr {
     // check for matching execution context
     bool matchesContext(const RequestPtr &req) const
     {
+        assert(contextId != InvalidContextID);
+        assert(req->hasContextId());
         return (contextId == req->contextId());
     }