linux-user: Support for restarting system calls for M68K targets

Update the M68K main loop and sigreturn code:
 * on TARGET_ERESTARTSYS, wind guest PC backwards to repeat syscall insn
 * set all guest CPU state within signal.c code on sigreturn
 * handle TARGET_QEMU_ESIGRETURN in the main loop as the indication
   that the main loop should not touch any guest CPU state

Signed-off-by: Timothy Edward Baldwin <T.E.Baldwin99@members.leeds.ac.uk>
Message-id: 1441497448-32489-32-git-send-email-T.E.Baldwin99@members.leeds.ac.uk
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
[PMM: tweak commit message; drop TARGET_USE_ERESTARTSYS define]
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
This commit is contained in:
Timothy E Baldwin 2016-05-12 18:47:39 +01:00 committed by Riku Voipio
parent 7fe7231a49
commit 7ccb84a916
3 changed files with 24 additions and 21 deletions

View file

@ -3086,18 +3086,24 @@ void cpu_loop(CPUM68KState *env)
break;
case EXCP_TRAP0:
{
abi_long ret;
ts->sim_syscalls = 0;
n = env->dregs[0];
env->pc += 2;
env->dregs[0] = do_syscall(env,
n,
env->dregs[1],
env->dregs[2],
env->dregs[3],
env->dregs[4],
env->dregs[5],
env->aregs[0],
0, 0);
ret = do_syscall(env,
n,
env->dregs[1],
env->dregs[2],
env->dregs[3],
env->dregs[4],
env->dregs[5],
env->aregs[0],
0, 0);
if (ret == -TARGET_ERESTARTSYS) {
env->pc -= 2;
} else if (ret != -TARGET_QEMU_ESIGRETURN) {
env->dregs[0] = ret;
}
}
break;
case EXCP_INTERRUPT: