Commit e6fe228c authored by Michael Ellerman's avatar Michael Ellerman Committed by Linus Torvalds
Browse files

powerpc/mm: Convert to using lock_mm_and_find_vma() 



Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent ae870a68

arch/powerpc/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -278,6 +278,7 @@ config PPC 
	select IRQ_DOMAIN

	select IRQ_FORCED_THREADING

	select KASAN_VMALLOC			if KASAN && MODULES

	select LOCK_MM_AND_FIND_VMA

	select MMU_GATHER_PAGE_SIZE

	select MMU_GATHER_RCU_TABLE_FREE

	select MMU_GATHER_MERGE_VMAS

arch/powerpc/mm/fault.c

+3 −36
Original line number Diff line number Diff line
@@ -84,11 +84,6 @@ static int __bad_area(struct pt_regs *regs, unsigned long address, int si_code) 
	return __bad_area_nosemaphore(regs, address, si_code);

}



static noinline int bad_area(struct pt_regs *regs, unsigned long address)

{

	return __bad_area(regs, address, SEGV_MAPERR);

}



static noinline int bad_access_pkey(struct pt_regs *regs, unsigned long address,

				    struct vm_area_struct *vma)

{
@@ -515,40 +510,12 @@ static int ___do_page_fault(struct pt_regs *regs, unsigned long address, 
	 * we will deadlock attempting to validate the fault against the

	 * address space.  Luckily the kernel only validly references user

	 * space from well defined areas of code, which are listed in the

	 * exceptions table.

	 *

	 * As the vast majority of faults will be valid we will only perform

	 * the source reference check when there is a possibility of a deadlock.

	 * Attempt to lock the address space, if we cannot we then validate the

	 * source.  If this is invalid we can skip the address space check,

	 * thus avoiding the deadlock.

	 * exceptions table. lock_mm_and_find_vma() handles that logic.

	 */

	if (unlikely(!mmap_read_trylock(mm))) {

		if (!is_user && !search_exception_tables(regs->nip))

			return bad_area_nosemaphore(regs, address);



retry:

		mmap_read_lock(mm);

	} else {

		/*

		 * The above down_read_trylock() might have succeeded in

		 * which case we'll have missed the might_sleep() from

		 * down_read():

		 */

		might_sleep();

	}



	vma = find_vma(mm, address);

	vma = lock_mm_and_find_vma(mm, address, regs);

	if (unlikely(!vma))

		return bad_area(regs, address);



	if (unlikely(vma->vm_start > address)) {

		if (unlikely(!(vma->vm_flags & VM_GROWSDOWN)))

			return bad_area(regs, address);



		if (unlikely(expand_stack(vma, address)))

			return bad_area(regs, address);

	}

		return bad_area_nosemaphore(regs, address);



	if (unlikely(access_pkey_error(is_write, is_exec,

				       (error_code & DSISR_KEYFAULT), vma)))