Commit fd3f1e0f authored by Nicholas Piggin's avatar Nicholas Piggin Committed by Michael Ellerman
Browse files

powerpc/traps: factor common code from program check and emulation assist 



Move the program check handling into a function called by both, rather
than have the emulation assist handler call the program check handler.

This allows each of these handlers to be implemented with "interrupt
wrappers" in a later change.

Signed-off-by: default avatarNicholas Piggin <npiggin@gmail.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1612702475.d6qyt6qtfy.astroid@bobo.none
parent 25b7e6bb

arch/powerpc/kernel/traps.c

+24 −14
Original line number Diff line number Diff line
@@ -1462,9 +1462,8 @@ static int emulate_math(struct pt_regs *regs) 
static inline int emulate_math(struct pt_regs *regs) { return -1; }

#endif



void program_check_exception(struct pt_regs *regs)

static void do_program_check(struct pt_regs *regs)

{

	enum ctx_state prev_state = exception_enter();

	unsigned int reason = get_reason(regs);



	/* We can now get here via a FP Unavailable exception if the core
@@ -1473,22 +1472,22 @@ void program_check_exception(struct pt_regs *regs) 
	if (reason & REASON_FP) {

		/* IEEE FP exception */

		parse_fpe(regs);

		goto bail;

		return;

	}

	if (reason & REASON_TRAP) {

		unsigned long bugaddr;

		/* Debugger is first in line to stop recursive faults in

		 * rcu_lock, notify_die, or atomic_notifier_call_chain */

		if (debugger_bpt(regs))

			goto bail;

			return;



		if (kprobe_handler(regs))

			goto bail;

			return;



		/* trap exception */

		if (notify_die(DIE_BPT, "breakpoint", regs, 5, 5, SIGTRAP)

				== NOTIFY_STOP)

			goto bail;

			return;



		bugaddr = regs->nip;

		/*
@@ -1500,10 +1499,10 @@ void program_check_exception(struct pt_regs *regs) 
		if (!(regs->msr & MSR_PR) &&  /* not user-mode */

		    report_bug(bugaddr, regs) == BUG_TRAP_TYPE_WARN) {

			regs->nip += 4;

			goto bail;

			return;

		}

		_exception(SIGTRAP, regs, TRAP_BRKPT, regs->nip);

		goto bail;

		return;

	}

#ifdef CONFIG_PPC_TRANSACTIONAL_MEM

	if (reason & REASON_TM) {
@@ -1524,7 +1523,7 @@ void program_check_exception(struct pt_regs *regs) 
		 */

		if (user_mode(regs)) {

			_exception(SIGILL, regs, ILL_ILLOPN, regs->nip);

			goto bail;

			return;

		} else {

			printk(KERN_EMERG "Unexpected TM Bad Thing exception "

			       "at %lx (msr 0x%lx) tm_scratch=%llx\n",
@@ -1557,7 +1556,7 @@ void program_check_exception(struct pt_regs *regs) 
	 * pattern to occurrences etc. -dgibson 31/Mar/2003

	 */

	if (!emulate_math(regs))

		goto bail;

		return;



	/* Try to emulate it if we should. */

	if (reason & (REASON_ILLEGAL | REASON_PRIVILEGED)) {
@@ -1565,10 +1564,10 @@ void program_check_exception(struct pt_regs *regs) 
		case 0:

			regs->nip += 4;

			emulate_single_step(regs);

			goto bail;

			return;

		case -EFAULT:

			_exception(SIGSEGV, regs, SEGV_MAPERR, regs->nip);

			goto bail;

			return;

		}

	}
@@ -1578,7 +1577,14 @@ void program_check_exception(struct pt_regs *regs) 
	else

		_exception(SIGILL, regs, ILL_ILLOPC, regs->nip);



bail:

}



void program_check_exception(struct pt_regs *regs)

{

	enum ctx_state prev_state = exception_enter();



	do_program_check(regs);



	exception_exit(prev_state);

}

NOKPROBE_SYMBOL(program_check_exception);
@@ -1589,8 +1595,12 @@ NOKPROBE_SYMBOL(program_check_exception); 
 */

void emulation_assist_interrupt(struct pt_regs *regs)

{

	enum ctx_state prev_state = exception_enter();



	regs->msr |= REASON_ILLEGAL;

	program_check_exception(regs);

	do_program_check(regs);



	exception_exit(prev_state);

}

NOKPROBE_SYMBOL(emulation_assist_interrupt);