From 8196fe9d83d6519128b514f332418bae06513970 Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Thu, 8 Apr 2021 17:24:02 +0100 Subject: target/arm: Make Thumb store insns UNDEF for Rn==1111 The Arm ARM specifies that for Thumb encodings of the various plain store insns, if the Rn field is 1111 then we must UNDEF. This is different from the Arm encodings, where this case is either UNPREDICTABLE or has well-defined behaviour. The exclusive stores, store-release and STRD do not have this UNDEF case for any encoding. Enforce the UNDEF for this case in the Thumb plain store insns. Fixes: https://bugs.launchpad.net/qemu/+bug/1922887 Signed-off-by: Peter Maydell Reviewed-by: Richard Henderson Message-id: 20210408162402.5822-1-peter.maydell@linaro.org --- target/arm/translate.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) (limited to 'target/arm') diff --git a/target/arm/translate.c b/target/arm/translate.c index 7103da2..68809e0 100644 --- a/target/arm/translate.c +++ b/target/arm/translate.c @@ -6476,6 +6476,14 @@ static bool op_store_rr(DisasContext *s, arg_ldst_rr *a, ISSInfo issinfo = make_issinfo(s, a->rt, a->p, a->w) | ISSIsWrite; TCGv_i32 addr, tmp; + /* + * In Thumb encodings of stores Rn=1111 is UNDEF; for Arm it + * is either UNPREDICTABLE or has defined behaviour + */ + if (s->thumb && a->rn == 15) { + return false; + } + addr = op_addr_rr_pre(s, a); tmp = load_reg(s, a->rt); @@ -6620,6 +6628,14 @@ static bool op_store_ri(DisasContext *s, arg_ldst_ri *a, ISSInfo issinfo = make_issinfo(s, a->rt, a->p, a->w) | ISSIsWrite; TCGv_i32 addr, tmp; + /* + * In Thumb encodings of stores Rn=1111 is UNDEF; for Arm it + * is either UNPREDICTABLE or has defined behaviour + */ + if (s->thumb && a->rn == 15) { + return false; + } + addr = op_addr_ri_pre(s, a); tmp = load_reg(s, a->rt); -- cgit v1.1