From: Andrew Morton <akpm@linux-foundation.org>
To: mm-commits@vger.kernel.org,ziy@nvidia.com,sj@kernel.org,richard.weiyang@gmail.com,lorenzo.stoakes@oracle.com,Liam.Howlett@oracle.com,david@redhat.com,akpm@linux-foundation.org
Subject: [merged mm-stable] mm-page_alloc-reject-unreasonable-folio-compound-page-sizes-in-alloc_contig_range_noprof.patch removed from -mm tree
Date: Sun, 21 Sep 2025 14:23:33 -0700 [thread overview]
Message-ID: <20250921212334.1C99AC4CEE7@smtp.kernel.org> (raw)
The quilt patch titled
Subject: mm/page_alloc: reject unreasonable folio/compound page sizes in alloc_contig_range_noprof()
has been removed from the -mm tree. Its filename was
mm-page_alloc-reject-unreasonable-folio-compound-page-sizes-in-alloc_contig_range_noprof.patch
This patch was dropped because it was merged into the mm-stable branch
of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
------------------------------------------------------
From: David Hildenbrand <david@redhat.com>
Subject: mm/page_alloc: reject unreasonable folio/compound page sizes in alloc_contig_range_noprof()
Date: Mon, 1 Sep 2025 17:03:27 +0200
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".
Link: https://lkml.kernel.org/r/20250901150359.867252-7-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
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: Andrew Morton <akpm@linux-foundation.org>
---
include/linux/mm.h | 6 ++++--
mm/page_alloc.c | 10 +++++++++-
2 files changed, 13 insertions(+), 3 deletions(-)
--- a/include/linux/mm.h~mm-page_alloc-reject-unreasonable-folio-compound-page-sizes-in-alloc_contig_range_noprof
+++ a/include/linux/mm.h
@@ -2055,11 +2055,13 @@ static inline long folio_nr_pages(const
/* 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
--- a/mm/page_alloc.c~mm-page_alloc-reject-unreasonable-folio-compound-page-sizes-in-alloc_contig_range_noprof
+++ a/mm/page_alloc.c
@@ -6838,6 +6838,7 @@ static int __alloc_contig_verify_gfp_mas
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;
@@ -6855,6 +6856,14 @@ int alloc_contig_range_noprof(unsigned l
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;
@@ -6952,7 +6961,6 @@ int alloc_contig_range_noprof(unsigned l
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);
_
Patches currently in -mm which might be from david@redhat.com are
reply other threads:[~2025-09-21 21:23 UTC|newest]
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