Commit bf0e2374 authored by Nicholas Piggin's avatar Nicholas Piggin Committed by Michael Ellerman
Browse files

powerpc/64s: split do_hash_fault 



This is required for subsequent interrupt wrapper implementation.

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/20210130130852.2952424-16-npiggin@gmail.com
parent f4c03b0e

arch/powerpc/mm/book3s64/hash_utils.c

+33 −23
Original line number Diff line number Diff line
@@ -1512,7 +1512,7 @@ int hash_page(unsigned long ea, unsigned long access, unsigned long trap, 
}

EXPORT_SYMBOL_GPL(hash_page);



long do_hash_fault(struct pt_regs *regs)

static long __do_hash_fault(struct pt_regs *regs)

{

	unsigned long ea = regs->dar;

	unsigned long dsisr = regs->dsisr;
@@ -1522,27 +1522,6 @@ long do_hash_fault(struct pt_regs *regs) 
	unsigned int region_id;

	long err;



	if (unlikely(dsisr & (DSISR_BAD_FAULT_64S | DSISR_KEYFAULT)))

		goto page_fault;



	/*

	 * If we are in an "NMI" (e.g., an interrupt when soft-disabled), then

	 * don't call hash_page, just fail the fault. This is required to

	 * prevent re-entrancy problems in the hash code, namely perf

	 * interrupts hitting while something holds H_PAGE_BUSY, and taking a

	 * hash fault. See the comment in hash_preload().

	 *

	 * We come here as a result of a DSI at a point where we don't want

	 * to call hash_page, such as when we are accessing memory (possibly

	 * user memory) inside a PMU interrupt that occurred while interrupts

	 * were soft-disabled.  We want to invoke the exception handler for

	 * the access, or panic if there isn't a handler.

	 */

	if (unlikely(in_nmi())) {

		bad_page_fault(regs, SIGSEGV);

		return 0;

	}



	region_id = get_region_id(ea);

	if ((region_id == VMALLOC_REGION_ID) || (region_id == IO_REGION_ID))

		mm = &init_mm;
@@ -1581,8 +1560,39 @@ long do_hash_fault(struct pt_regs *regs) 
			bad_page_fault(regs, SIGBUS);

		}

		err = 0;

	}



	return err;

}



long do_hash_fault(struct pt_regs *regs)

{

	unsigned long dsisr = regs->dsisr;

	long err;



	if (unlikely(dsisr & (DSISR_BAD_FAULT_64S | DSISR_KEYFAULT)))

		goto page_fault;



	/*

	 * If we are in an "NMI" (e.g., an interrupt when soft-disabled), then

	 * don't call hash_page, just fail the fault. This is required to

	 * prevent re-entrancy problems in the hash code, namely perf

	 * interrupts hitting while something holds H_PAGE_BUSY, and taking a

	 * hash fault. See the comment in hash_preload().

	 *

	 * We come here as a result of a DSI at a point where we don't want

	 * to call hash_page, such as when we are accessing memory (possibly

	 * user memory) inside a PMU interrupt that occurred while interrupts

	 * were soft-disabled.  We want to invoke the exception handler for

	 * the access, or panic if there isn't a handler.

	 */

	if (unlikely(in_nmi())) {

		bad_page_fault(regs, SIGSEGV);

		return 0;

	}



	} else if (err) {

	err = __do_hash_fault(regs);

	if (err) {

page_fault:

		err = do_page_fault(regs);

	}