diff mbox series

[1/7] target/arm/translate-a64: Don't underdecode system instructions

Message ID 20190125182626.9221-2-peter.maydell@linaro.org
State Superseded
Headers show
Series target/arm: Fix various underdecodings | expand

Commit Message

Peter Maydell Jan. 25, 2019, 6:26 p.m. UTC 
The "system instructions" and "system register move" subcategories
of "branches, exception generating and system instructions" for A64
only apply if bits [23:22] are zero; other values are currently
unallocated. Correctly UNDEF these unallocated encodings.

Reported-by: Laurent Desnogues <laurent.desnogues@gmail.com>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

---
 target/arm/translate-a64.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

-- 
2.20.1

Comments

Laurent Desnogues Jan. 28, 2019, 11:09 a.m. UTC | #1 
On Fri, Jan 25, 2019 at 7:26 PM Peter Maydell <peter.maydell@linaro.org> wrote:
>

> The "system instructions" and "system register move" subcategories

> of "branches, exception generating and system instructions" for A64

> only apply if bits [23:22] are zero; other values are currently

> unallocated. Correctly UNDEF these unallocated encodings.

>

> Reported-by: Laurent Desnogues <laurent.desnogues@gmail.com>

> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>


Reviewed-by: Laurent Desnogues <laurent.desnogues@gmail.com>


Thanks,

Laurent

> ---

>  target/arm/translate-a64.c | 6 +++++-

>  1 file changed, 5 insertions(+), 1 deletion(-)

>

> diff --git a/target/arm/translate-a64.c b/target/arm/translate-a64.c

> index 4d28a27c3bd..e6df303e321 100644

> --- a/target/arm/translate-a64.c

> +++ b/target/arm/translate-a64.c

> @@ -2144,7 +2144,11 @@ static void disas_b_exc_sys(DisasContext *s, uint32_t insn)

>          break;

>      case 0x6a: /* Exception generation / System */

>          if (insn & (1 << 24)) {

> -            disas_system(s, insn);

> +            if (extract32(insn, 22, 2) == 0) {

> +                disas_system(s, insn);

> +            } else {

> +                unallocated_encoding(s);

> +            }

>          } else {

>              disas_exc(s, insn);

>          }

> --

> 2.20.1

>
diff mbox series

Patch

diff --git a/target/arm/translate-a64.c b/target/arm/translate-a64.c
index 4d28a27c3bd..e6df303e321 100644
--- a/target/arm/translate-a64.c
+++ b/target/arm/translate-a64.c
@@ -2144,7 +2144,11 @@  static void disas_b_exc_sys(DisasContext *s, uint32_t insn)
         break;
     case 0x6a: /* Exception generation / System */
         if (insn & (1 << 24)) {
-            disas_system(s, insn);
+            if (extract32(insn, 22, 2) == 0) {
+                disas_system(s, insn);
+            } else {
+                unallocated_encoding(s);
+            }
         } else {
             disas_exc(s, insn);
         }