Commit 5c6f4d68 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'mm-stable-2024-05-22-17-22' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm 

Pull more mm updates from Andrew Morton:
 "A series from Dave Chinner which cleans up and fixes the handling of
  nested allocations within stackdepot and page-owner"

* tag 'mm-stable-2024-05-22-17-22' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
  mm/page-owner: use gfp_nested_mask() instead of open coded masking
  stackdepot: use gfp_nested_mask() instead of open coded masking
  mm: lift gfp_kmemleak_mask() to gfp.h
parents de7e71ef 99b80ac4

include/linux/gfp.h

+25 −0
Original line number Diff line number Diff line
@@ -156,6 +156,31 @@ static inline int gfp_zonelist(gfp_t flags) 
	return ZONELIST_FALLBACK;

}



/*

 * gfp flag masking for nested internal allocations.

 *

 * For code that needs to do allocations inside the public allocation API (e.g.

 * memory allocation tracking code) the allocations need to obey the caller

 * allocation context constrains to prevent allocation context mismatches (e.g.

 * GFP_KERNEL allocations in GFP_NOFS contexts) from potential deadlock

 * situations.

 *

 * It is also assumed that these nested allocations are for internal kernel

 * object storage purposes only and are not going to be used for DMA, etc. Hence

 * we strip out all the zone information and leave just the context information

 * intact.

 *

 * Further, internal allocations must fail before the higher level allocation

 * can fail, so we must make them fail faster and fail silently. We also don't

 * want them to deplete emergency reserves.  Hence nested allocations must be

 * prepared for these allocations to fail.

 */

static inline gfp_t gfp_nested_mask(gfp_t flags)

{

	return ((flags & (GFP_KERNEL | GFP_ATOMIC | __GFP_NOLOCKDEP)) |

		(__GFP_NORETRY | __GFP_NOMEMALLOC | __GFP_NOWARN));

}



/*

 * We get the zone list from the current node and the gfp_mask.

 * This zone list contains a maximum of MAX_NUMNODES*MAX_NR_ZONES zones.

lib/stackdepot.c

+2 −9
Original line number Diff line number Diff line
@@ -624,15 +624,8 @@ depot_stack_handle_t stack_depot_save_flags(unsigned long *entries, 
	 * we won't be able to do that under the lock.

	 */

	if (unlikely(can_alloc && !READ_ONCE(new_pool))) {

		/*

		 * Zero out zone modifiers, as we don't have specific zone

		 * requirements. Keep the flags related to allocation in atomic

		 * contexts, I/O, nolockdep.

		 */

		alloc_flags &= ~GFP_ZONEMASK;

		alloc_flags &= (GFP_ATOMIC | GFP_KERNEL | __GFP_NOLOCKDEP);

		alloc_flags |= __GFP_NOWARN;

		page = alloc_pages(alloc_flags, DEPOT_POOL_ORDER);

		page = alloc_pages(gfp_nested_mask(alloc_flags),

				   DEPOT_POOL_ORDER);

		if (page)

			prealloc = page_address(page);

	}

mm/kmemleak.c

+4 −8
Original line number Diff line number Diff line
@@ -114,12 +114,6 @@ 


#define BYTES_PER_POINTER	sizeof(void *)



/* GFP bitmask for kmemleak internal allocations */

#define gfp_kmemleak_mask(gfp)	(((gfp) & (GFP_KERNEL | GFP_ATOMIC | \

					   __GFP_NOLOCKDEP)) | \

				 __GFP_NORETRY | __GFP_NOMEMALLOC | \

				 __GFP_NOWARN)



/* scanning area inside a memory block */

struct kmemleak_scan_area {

	struct hlist_node node;
@@ -463,7 +457,8 @@ static struct kmemleak_object *mem_pool_alloc(gfp_t gfp) 


	/* try the slab allocator first */

	if (object_cache) {

		object = kmem_cache_alloc_noprof(object_cache, gfp_kmemleak_mask(gfp));

		object = kmem_cache_alloc_noprof(object_cache,

						 gfp_nested_mask(gfp));

		if (object)

			return object;

	}
@@ -947,7 +942,8 @@ static void add_scan_area(unsigned long ptr, size_t size, gfp_t gfp) 
	untagged_objp = (unsigned long)kasan_reset_tag((void *)object->pointer);



	if (scan_area_cache)

		area = kmem_cache_alloc_noprof(scan_area_cache, gfp_kmemleak_mask(gfp));

		area = kmem_cache_alloc_noprof(scan_area_cache,

					       gfp_nested_mask(gfp));



	raw_spin_lock_irqsave(&object->lock, flags);

	if (!area) {

mm/page_owner.c

+1 −6
Original line number Diff line number Diff line
@@ -168,13 +168,8 @@ static void add_stack_record_to_list(struct stack_record *stack_record, 
	unsigned long flags;

	struct stack *stack;



	/* Filter gfp_mask the same way stackdepot does, for consistency */

	gfp_mask &= ~GFP_ZONEMASK;

	gfp_mask &= (GFP_ATOMIC | GFP_KERNEL | __GFP_NOLOCKDEP);

	gfp_mask |= __GFP_NOWARN;



	set_current_in_page_owner();

	stack = kmalloc(sizeof(*stack), gfp_mask);

	stack = kmalloc(sizeof(*stack), gfp_nested_mask(gfp_mask));

	if (!stack) {

		unset_current_in_page_owner();

		return;