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[PULL,25/47] target/arm/translate-a64: Don't underdecode system instructions

Message ID 20190201160653.13829-26-peter.maydell@linaro.org
State New
Headers show
Series [PULL,01/47] hw/arm/nrf51_soc: set object owner in memory_region_init_ram | expand

Commit Message

Peter Maydell Feb. 1, 2019, 4:06 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>
Reviewed-by: Laurent Desnogues <laurent.desnogues@gmail.com>
Message-id: 20190125182626.9221-2-peter.maydell@linaro.org
---
 target/arm/translate-a64.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)
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);
         }