[Valgrind-developers] [valgrind] s390x: Fix down-cast from memory operand with size < 8

[Andreas A. <ar...@so...>]

https://sourceware.org/git/gitweb.cgi?p=valgrind.git;h=b9a4f7d7ca98487e7b66c2c56bc0c9ea7fe6776b

commit b9a4f7d7ca98487e7b66c2c56bc0c9ea7fe6776b
Author: Andreas Arnez <ar...@li...>
Date:   Tue Mar 10 17:18:48 2020 +0100

    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:
---
 VEX/priv/host_s390_isel.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

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: