target/i386: decode-new: avoid out-of-bounds access to xmm_regs[-1]

If the destination is a memory register, op->n is -1.  Going through
tcg_gen_gvec_dup_imm path is both useless (the value has been stored
by the gen_* function already) and wrong because of the out-of-bounds
access.

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/target/i386/tcg/emit.c.inc b/target/i386/tcg/emit.c.inc
index 27eca591a999ee38cefb411b8f6f26ed01c74d27..ebf299451dffa3a471500ab9d691a135e78d332b 100644 (file)
--- a/target/i386/tcg/emit.c.inc
+++ b/target/i386/tcg/emit.c.inc
@@ -296,7 +296,7 @@ static void gen_writeback(DisasContext *s, X86DecodedInsn *decode, int opn, TCGv
     case X86_OP_MMX:
         break;
     case X86_OP_SSE:
-        if ((s->prefix & PREFIX_VEX) && op->ot == MO_128) {
+        if (!op->has_ea && (s->prefix & PREFIX_VEX) && op->ot == MO_128) {
             tcg_gen_gvec_dup_imm(MO_64,
                                  offsetof(CPUX86State, xmm_regs[op->n].ZMM_X(1)),
                                  16, 16, 0);