From: Andreas Arnez <arnez@linux.ibm.com>
Date: Tue, 10 Mar 2020 16:18:48 +0000 (+0100)
Subject: s390x: Fix down-cast from memory operand with size < 8
X-Git-Tag: VALGRIND_3_16_0~76
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=b9a4f7d7ca98487e7b66c2c56bc0c9ea7fe6776b;p=thirdparty%2Fvalgrind.git

s390x: Fix down-cast from memory operand with size < 8

A down-cast always copies 8 bytes from the source operand, even if the
operand is actually smaller.  This doesn't matter for register operands,
but it does for memory operands.  Fix this and copy the correct number of
bytes instead.
---

diff --git a/VEX/priv/host_s390_isel.c b/VEX/priv/host_s390_isel.c
index 5d26825daf..00b4aee818 100644
--- a/VEX/priv/host_s390_isel.c
+++ b/VEX/priv/host_s390_isel.c
@@ -1893,7 +1893,8 @@ s390_isel_int_expr_wrk(ISelEnv *env, IRExpr *expr)
          /* Down-casts are no-ops. Upstream operations will only look at
             the bytes that make up the result of the down-cast. So there
             is no point setting the other bytes to 0. */
-         insn = s390_opnd_copy(8, dst, opnd);
+         size = sizeofIRType(typeOfIRExpr(env->type_env, arg));
+         insn = s390_opnd_copy(size, dst, opnd);
          break;
 
       case Iop_64HIto32: