From: Tony Gutierrez <anthony.gutierrez@amd.com>
Date: Fri, 2 Dec 2016 16:40:52 +0000 (-0500)
Subject: hsail: fix unsigned offset bug in address calculation
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=38708f369bc5ec6f6a4db973d0413f0b3ce7f97a;p=gem5.git

hsail: fix unsigned offset bug in address calculation

it's possible for the offset provided to an HSAIL mem inst to be a negative
value, however the variable we use to hold the offset is an unsigned type.
this can lead to excessively large offset values when the offset is negative,
which will almost certainly cause the access to go out of bounds.
---

diff --git a/src/arch/hsail/operand.hh b/src/arch/hsail/operand.hh
index 4d981ee00..3fbb0991a 100644
--- a/src/arch/hsail/operand.hh
+++ b/src/arch/hsail/operand.hh
@@ -591,7 +591,7 @@ class AddrOperandBase : public BaseOperand
     virtual void calcVector(Wavefront *w, std::vector<Addr> &addrVec) = 0;
     virtual uint64_t calcLane(Wavefront *w, int lane=0) = 0;
 
-    uint64_t offset;
+    int64_t offset;
     const char *name = nullptr;
     StorageElement *storageElement;
 };
@@ -627,14 +627,24 @@ RegAddrOperand<RegOperandType>::init(unsigned opOffset, const BrigObject *obj)
             const BrigOperandAddress *op = (BrigOperandAddress*)baseOp;
             storageElement = nullptr;
 
-            offset = (uint64_t(op->offset.hi) << 32) | uint64_t(op->offset.lo);
             reg.init(op->reg, obj);
 
             if (reg.regFileChar == 's') {
+                // if the address expression is 32b, then the hi
+                // bits of the offset must be set to 0 in the BRIG
+                assert(!op->offset.hi);
+                /**
+                 * the offset field of an HSAIL instruction may be negative
+                 * so here we cast the raw bits we get from the BRIG file to
+                 * a signed type to avoid address calculation errors
+                 */
+                offset = (int32_t)(op->offset.lo);
                 reg.regOperandSize = sizeof(uint32_t);
                 registerType = Enums::RT_VECTOR;
             }
             else if (reg.regFileChar == 'd') {
+                offset = (int64_t)(((uint64_t)(op->offset.hi) << 32)
+                    | (uint64_t)(op->offset.lo));
                 reg.regOperandSize = sizeof(uint64_t);
                 registerType = Enums::RT_VECTOR;
             }