void
cpu_set_syscall_retval(struct thread *td, int error)
{
switch (error) {
case 0:
td->td_frame->tf_out[0] = td->td_retval[0];
td->td_frame->tf_out[1] = td->td_retval[1];
td->td_frame->tf_tstate &= ~TSTATE_XCC_C;
break;
case ERESTART:
/*
* Undo the tpc advancement we have done on syscall
* enter, we want to reexecute the system call.
*/
td->td_frame->tf_tpc = td->td_pcb->pcb_tpc;
td->td_frame->tf_tnpc -= 4;
break;
case EJUSTRETURN:
break;
default:
td->td_frame->tf_out[0] = SV_ABI_ERRNO(td->td_proc, error);
td->td_frame->tf_tstate |= TSTATE_XCC_C;
break;
}
}
void
cpu_set_syscall_retval(struct thread *td, int error)
{
switch (error) {
case 0:
td->td_frame->tf_rax = td->td_retval[0];
td->td_frame->tf_rdx = td->td_retval[1];
td->td_frame->tf_rflags &= ~PSL_C;
break;
case ERESTART:
/*
* Reconstruct pc, we know that 'syscall' is 2 bytes,
* lcall $X,y is 7 bytes, int 0x80 is 2 bytes.
* We saved this in tf_err.
* %r10 (which was holding the value of %rcx) is restored
* for the next iteration.
* %r10 restore is only required for freebsd/amd64 processes,
* but shall be innocent for any ia32 ABI.
*
* Require full context restore to get the arguments
* in the registers reloaded at return to usermode.
*/
td->td_frame->tf_rip -= td->td_frame->tf_err;
td->td_frame->tf_r10 = td->td_frame->tf_rcx;
set_pcb_flags(td->td_pcb, PCB_FULL_IRET);
break;
case EJUSTRETURN:
break;
default:
td->td_frame->tf_rax = SV_ABI_ERRNO(td->td_proc, error);
td->td_frame->tf_rflags |= PSL_C;
break;
}
}
void
cpu_set_syscall_retval(struct thread *td, int error)
{
struct trapframe *frame;
frame = td->td_frame;
switch (error) {
case 0:
frame->tf_x[0] = td->td_retval[0];
frame->tf_x[1] = td->td_retval[1];
frame->tf_spsr &= ~PSR_C; /* carry bit */
break;
case ERESTART:
frame->tf_elr -= 4;
break;
case EJUSTRETURN:
break;
default:
frame->tf_spsr |= PSR_C; /* carry bit */
frame->tf_x[0] = SV_ABI_ERRNO(td->td_proc, error);
break;
}
}
