/*
* Find out which address space caused the exception.
* Access register mode is impossible, ignore space == 3.
*/
static inline enum fault_type get_fault_type(struct pt_regs *regs)
{
unsigned long trans_exc_code;
trans_exc_code = regs->int_parm_long & 3;
if (likely(trans_exc_code == 0)) {
/* primary space exception */
if (IS_ENABLED(CONFIG_PGSTE) &&
test_pt_regs_flag(regs, PIF_GUEST_FAULT))
return GMAP_FAULT;
if (current->thread.mm_segment == USER_DS)
return USER_FAULT;
return KERNEL_FAULT;
}
if (trans_exc_code == 2) {
/* secondary space exception */
if (current->thread.mm_segment & 1) {
if (current->thread.mm_segment == USER_DS_SACF)
return USER_FAULT;
return KERNEL_FAULT;
}
return VDSO_FAULT;
}
/* home space exception -> access via kernel ASCE */
return KERNEL_FAULT;
}
/*
* Note that 'init' is a special process: it doesn't get signals it doesn't
* want to handle. Thus you cannot kill init even with a SIGKILL even by
* mistake.
*
* Note that we go through the signals twice: once to check the signals that
* the kernel can handle, and then we build all the user-level signal handling
* stack-frames in one go after that.
*/
void do_signal(struct pt_regs *regs)
{
siginfo_t info;
int signr;
struct k_sigaction ka;
sigset_t *oldset = sigmask_to_save();
/*
* Get signal to deliver. When running under ptrace, at this point
* the debugger may change all our registers, including the system
* call information.
*/
current_thread_info()->system_call =
test_pt_regs_flag(regs, PIF_SYSCALL) ? regs->int_code : 0;
signr = get_signal_to_deliver(&info, &ka, regs, NULL);
if (signr > 0) {
/* Whee! Actually deliver the signal. */
if (current_thread_info()->system_call) {
regs->int_code = current_thread_info()->system_call;
/* Check for system call restarting. */
switch (regs->gprs[2]) {
case -ERESTART_RESTARTBLOCK:
case -ERESTARTNOHAND:
regs->gprs[2] = -EINTR;
break;
case -ERESTARTSYS:
if (!(ka.sa.sa_flags & SA_RESTART)) {
regs->gprs[2] = -EINTR;
break;
}
/* fallthrough */
case -ERESTARTNOINTR:
regs->gprs[2] = regs->orig_gpr2;
regs->psw.addr =
__rewind_psw(regs->psw,
regs->int_code >> 16);
break;
}
}
/* No longer in a system call */
clear_pt_regs_flag(regs, PIF_SYSCALL);
if (is_compat_task())
handle_signal32(signr, &ka, &info, oldset, regs);
else
handle_signal(signr, &ka, &info, oldset, regs);
return;
}