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authorPeter Maydell <peter.maydell@linaro.org>2021-04-08 17:24:02 +0100
committerPeter Maydell <peter.maydell@linaro.org>2021-04-30 11:16:49 +0100
commit8196fe9d83d6519128b514f332418bae06513970 (patch)
treeef7ba90be1eaed8a1a8aab69e6edde42bd0bb8be
parentbf559ee4025adaf9713e22def862d31f1db5994e (diff)
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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 <peter.maydell@linaro.org> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Message-id: 20210408162402.5822-1-peter.maydell@linaro.org
-rw-r--r--target/arm/translate.c16
1 files changed, 16 insertions, 0 deletions
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);