Commit 11ccdd33 authored by Benjamin Herrenschmidt's avatar Benjamin Herrenschmidt Committed by Michael Ellerman
Browse files

powerpc/mm: Move/simplify faulthandler_disabled() and !mm check 



Do the check before we re-enable interrupts and clean the code
up a bit.

Signed-off-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
parent 2865d08d

arch/powerpc/mm/fault.c

+13 −14
Original line number Diff line number Diff line
@@ -355,24 +355,23 @@ static int __do_page_fault(struct pt_regs *regs, unsigned long address, 
	if (unlikely(!is_user && bad_kernel_fault(is_exec, error_code, address)))

		return SIGSEGV;



	/*

	 * If we're in an interrupt, have no user context or are running

	 * in a region with pagefaults disabled then we must not take the fault

	 */

	if (unlikely(faulthandler_disabled() || !mm)) {

		if (is_user)

			printk_ratelimited(KERN_ERR "Page fault in user mode"

					   " with faulthandler_disabled()=%d"

					   " mm=%p\n",

					   faulthandler_disabled(), mm);

		return bad_area_nosemaphore(regs, address);

	}



	/* We restore the interrupt state now */

	if (!arch_irq_disabled_regs(regs))

		local_irq_enable();



	if (faulthandler_disabled() || mm == NULL) {

		if (!is_user)

			return SIGSEGV;



		/* faulthandler_disabled() in user mode is really bad,

		   as is current->mm == NULL. */

		printk(KERN_EMERG "Page fault in user mode with "

		       "faulthandler_disabled() = %d mm = %p\n",

		       faulthandler_disabled(), mm);

		printk(KERN_EMERG "NIP = %lx  MSR = %lx\n",

		       regs->nip, regs->msr);

		die("Weird page fault", regs, SIGSEGV);

	}



	perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address);



	/*