Commit 0c24811b authored by Matthew Wilcox (Oracle)'s avatar Matthew Wilcox (Oracle) Committed by Vlastimil Babka
Browse files

mm: Convert __ksize() to struct slab 



In SLUB, use folios, and struct slab to access slab_cache field.
In SLOB, use folios to properly resolve pointers beyond
PAGE_SIZE offset of the object.

[ vbabka@suse.cz: use folios, and only convert folio_test_slab() == true
  folios to struct slab ]

Signed-off-by: default avatarMatthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: default avatarVlastimil Babka <vbabka@suse.cz>
Acked-by: default avatarJohannes Weiner <hannes@cmpxchg.org>
Reviewed-by: default avatarRoman Gushchin <guro@fb.com>
parent 82c1775d

mm/slob.c

+4 −4
Original line number Diff line number Diff line
@@ -570,7 +570,7 @@ EXPORT_SYMBOL(kfree); 
/* can't use ksize for kmem_cache_alloc memory, only kmalloc */

size_t __ksize(const void *block)

{

	struct page *sp;

	struct folio *folio;

	int align;

	unsigned int *m;
@@ -578,9 +578,9 @@ size_t __ksize(const void *block) 
	if (unlikely(block == ZERO_SIZE_PTR))

		return 0;



	sp = virt_to_page(block);

	if (unlikely(!PageSlab(sp)))

		return page_size(sp);

	folio = virt_to_folio(block);

	if (unlikely(!folio_test_slab(folio)))

		return folio_size(folio);



	align = max_t(size_t, ARCH_KMALLOC_MINALIGN, ARCH_SLAB_MINALIGN);

	m = (unsigned int *)(block - align);

mm/slub.c

+5 −7
Original line number Diff line number Diff line
@@ -4527,19 +4527,17 @@ void __check_heap_object(const void *ptr, unsigned long n, struct page *page, 


size_t __ksize(const void *object)

{

	struct page *page;

	struct folio *folio;



	if (unlikely(object == ZERO_SIZE_PTR))

		return 0;



	page = virt_to_head_page(object);

	folio = virt_to_folio(object);



	if (unlikely(!PageSlab(page))) {

		WARN_ON(!PageCompound(page));

		return page_size(page);

	}

	if (unlikely(!folio_test_slab(folio)))

		return folio_size(folio);



	return slab_ksize(page->slab_cache);

	return slab_ksize(folio_slab(folio)->slab_cache);

}

EXPORT_SYMBOL(__ksize);