target-xtensa: return ENOSYS for unimplemented simcalls

This prevents guest from proceeding with uninitialised garbage returned
from unimplemented simcalls.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>

diff --git a/target-xtensa/xtensa-semi.c b/target-xtensa/xtensa-semi.c
index 1c8a19ed5673b00e1418c09e83310f825da9e264..6d001c2c1aa2d1d53fa109235fd5b31078ff327c 100644 (file)
--- a/target-xtensa/xtensa-semi.c
+++ b/target-xtensa/xtensa-semi.c
@@ -218,6 +218,8 @@ void HELPER(simcall)(CPUXtensaState *env)
 
     default:
         qemu_log("%s(%d): not implemented\n", __func__, regs[2]);
+        regs[2] = -1;
+        regs[3] = ENOSYS;
         break;
     }
 }