Let's reject them early, which in turn makes folio_alloc_gigantic() reject them properly.
To avoid converting from order to nr_pages, let's just add MAX_FOLIO_ORDER and calculate MAX_FOLIO_NR_PAGES based on that.
While at it, let's just make the order a "const unsigned order".
Reviewed-by: Zi Yan ziy@nvidia.com Acked-by: SeongJae Park sj@kernel.org Reviewed-by: Wei Yang richard.weiyang@gmail.com Reviewed-by: Lorenzo Stoakes lorenzo.stoakes@oracle.com Reviewed-by: Liam R. Howlett Liam.Howlett@oracle.com Signed-off-by: David Hildenbrand david@redhat.com --- include/linux/mm.h | 6 ++++-- mm/page_alloc.c | 10 +++++++++- 2 files changed, 13 insertions(+), 3 deletions(-)
diff --git a/include/linux/mm.h b/include/linux/mm.h index 00c8a54127d37..77737cbf2216a 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -2055,11 +2055,13 @@ static inline long folio_nr_pages(const struct folio *folio)
/* Only hugetlbfs can allocate folios larger than MAX_ORDER */ #ifdef CONFIG_ARCH_HAS_GIGANTIC_PAGE -#define MAX_FOLIO_NR_PAGES (1UL << PUD_ORDER) +#define MAX_FOLIO_ORDER PUD_ORDER #else -#define MAX_FOLIO_NR_PAGES MAX_ORDER_NR_PAGES +#define MAX_FOLIO_ORDER MAX_PAGE_ORDER #endif
+#define MAX_FOLIO_NR_PAGES (1UL << MAX_FOLIO_ORDER) + /* * compound_nr() returns the number of pages in this potentially compound * page. compound_nr() can be called on a tail page, and is defined to diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 27ea4c7acd158..7e96c69a06ccb 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -6841,6 +6841,7 @@ static int __alloc_contig_verify_gfp_mask(gfp_t gfp_mask, gfp_t *gfp_cc_mask) int alloc_contig_range_noprof(unsigned long start, unsigned long end, acr_flags_t alloc_flags, gfp_t gfp_mask) { + const unsigned int order = ilog2(end - start); unsigned long outer_start, outer_end; int ret = 0;
@@ -6858,6 +6859,14 @@ int alloc_contig_range_noprof(unsigned long start, unsigned long end, PB_ISOLATE_MODE_CMA_ALLOC : PB_ISOLATE_MODE_OTHER;
+ /* + * In contrast to the buddy, we allow for orders here that exceed + * MAX_PAGE_ORDER, so we must manually make sure that we are not + * exceeding the maximum folio order. + */ + if (WARN_ON_ONCE((gfp_mask & __GFP_COMP) && order > MAX_FOLIO_ORDER)) + return -EINVAL; + gfp_mask = current_gfp_context(gfp_mask); if (__alloc_contig_verify_gfp_mask(gfp_mask, (gfp_t *)&cc.gfp_mask)) return -EINVAL; @@ -6955,7 +6964,6 @@ int alloc_contig_range_noprof(unsigned long start, unsigned long end, free_contig_range(end, outer_end - end); } else if (start == outer_start && end == outer_end && is_power_of_2(end - start)) { struct page *head = pfn_to_page(start); - int order = ilog2(end - start);
check_new_pages(head, order); prep_new_page(head, order, gfp_mask, 0);