+ mm-hugetlb_cma-validate-hugetlb-cma-range-by-zone-at-reserve-time.patch added to mm-new branch

+ mm-hugetlb_cma-validate-hugetlb-cma-range-by-zone-at-reserve-time.patch added to mm-new branch

[Andrew Morton]

The patch titled
     Subject: mm/hugetlb_cma: validate hugetlb CMA range by zone at reserve time
has been added to the -mm mm-new branch.  Its filename is
     mm-hugetlb_cma-validate-hugetlb-cma-range-by-zone-at-reserve-time.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-hugetlb_cma-validate-hugetlb-cma-range-by-zone-at-reserve-time.patch

This patch will later appear in the mm-new branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Note, mm-new is a provisional staging ground for work-in-progress
patches, and acceptance into mm-new is a notification for others take
notice and to finish up reviews.  Please do not hesitate to respond to
review feedback and post updated versions to replace or incrementally
fixup patches in mm-new.

The mm-new branch of mm.git is not included in linux-next

If a few days of testing in mm-new is successful, the patch will me moved
into mm.git's mm-unstable branch, which is included in linux-next

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------------------------------------------------------
From: Muchun Song <songmuchun@bytedance.com>
Subject: mm/hugetlb_cma: validate hugetlb CMA range by zone at reserve time
Date: Fri, 12 Jun 2026 11:58:56 +0800

Hugetlb CMA allocation currently has to cope with CMA areas that span
multiple zones.

Validate the reserved CMA range up front in hugetlb_cma_reserve() so later
hugetlb CMA allocations can assume a zone-consistent area.

Also drop the pfn_valid() check from cma_validate_zones().  mem_section is
not fully initialized at this point, so the check can trigger false
warnings.  Keep the sanity check in cma_activate_area() instead.

Link: https://lore.kernel.org/20260612035903.2468601-13-songmuchun@bytedance.com
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Reviewed-by: Oscar Salvador (SUSE) <osalvador@suse.de>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>
Cc: David Hildenbrand <david@kernel.org>
Cc: Frank van der Linden <fvdl@google.com>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Oscar Salvador (SUSE) <osalvador@kernel.org>
Cc: "Ritesh Harjani (IBM)" <ritesh.list@gmail.com>
Cc: Usama Arif <usama.arif@linux.dev>
Cc: Vlastimil Babka <vbabka@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/cma.c         |    3 ++-
 mm/hugetlb_cma.c |    6 ++++--
 2 files changed, 6 insertions(+), 3 deletions(-)

--- a/mm/cma.c~mm-hugetlb_cma-validate-hugetlb-cma-range-by-zone-at-reserve-time
+++ a/mm/cma.c
@@ -126,7 +126,6 @@ bool cma_validate_zones(struct cma *cma)
 		 * to be in the same zone. Simplify by forcing the entire
 		 * CMA resv range to be in the same zone.
 		 */
-		WARN_ON_ONCE(!pfn_valid(base_pfn));
 		if (pfn_range_intersects_zones(cma->nid, base_pfn, cmr->count)) {
 			set_bit(CMA_ZONES_INVALID, &cma->flags);
 			return false;
@@ -165,6 +164,8 @@ static void __init cma_activate_area(str
 			bitmap_set(cmr->bitmap, 0, bitmap_count);
 		}
 
+		WARN_ON_ONCE(!pfn_valid(cmr->base_pfn));
+
 		for (pfn = early_pfn[r]; pfn < cmr->base_pfn + cmr->count;
 		     pfn += pageblock_nr_pages)
 			init_cma_reserved_pageblock(pfn_to_page(pfn));
--- a/mm/hugetlb_cma.c~mm-hugetlb_cma-validate-hugetlb-cma-range-by-zone-at-reserve-time
+++ a/mm/hugetlb_cma.c
@@ -231,9 +231,11 @@ void __init hugetlb_cma_reserve(void)
 		res = cma_declare_contiguous_multi(size, gigantic_page_size,
 					HUGETLB_PAGE_ORDER, name,
 					&hugetlb_cma[nid], nid);
-		if (res) {
-			pr_warn("hugetlb_cma: reservation failed: err %d, node %d",
+		if (res || !cma_validate_zones(hugetlb_cma[nid])) {
+			pr_warn("hugetlb_cma: %s: err %d, node %d\n",
+				res ? "reservation failed" : "reserved area spans zones",
 				res, nid);
+			hugetlb_cma[nid] = NULL;
 			continue;
 		}
 
_

Patches currently in -mm which might be from songmuchun@bytedance.com are

mm-hugetlb-fix-boot-panic-with-config_debug_vm-and-hvo-bootmem-pages.patch
mm-hugetlb_vmemmap-fix-__hugetlb_vmemmap_optimize_folios.patch
powerpc-mm-fix-wrong-addr_pfn-tracking-in-compound-vmemmap-population.patch
mm-hugetlb-initialize-gigantic-bootmem-hugepage-struct-pages-earlier.patch
mm-mm_init-simplify-deferred_free_pages-migratetype-init.patch
mm-sparse-panic-on-memmap-and-usemap-allocation-failure.patch
mm-sparse-move-subsection_map_init-into-sparse_init.patch
mm-mm_init-defer-sparse_init-until-after-zone-initialization.patch
mm-mm_init-defer-hugetlb-reservation-until-after-zone-initialization.patch
mm-mm_init-remove-set_pageblock_order-call-from-sparse_init.patch
mm-sparse-move-sparse_vmemmap_init_nid_late-into-sparse_init_nid.patch
mm-hugetlb_cma-validate-hugetlb-cma-range-by-zone-at-reserve-time.patch
mm-hugetlb-refactor-early-boot-gigantic-hugepage-allocation.patch
mm-hugetlb-free-cross-zone-bootmem-gigantic-pages-after-allocation.patch
mm-hugetlb_vmemmap-move-bootmem-hvo-setup-to-early-init.patch
mm-hugetlb-remove-obsolete-bootmem-cross-zone-checks.patch
mm-sparse-vmemmap-remove-sparse_vmemmap_init_nid_late.patch
mm-hugetlb-remove-unused-bootmem-cma-field.patch
mm-mm_init-fold-__init_page_from_nid-into-__init_deferred_page.patch