Merge tag 'mm-stable-2026-10-25-19-27' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull more MM updates from Andrew Morton:

 - "mm: make VMA flag semantics explicit, eliminate VM_SPECIAL" (Lorenzo
   Stoakes):

   Replace VM_SPECIAL with helpers describing mapping ownership and
   behavior. Enforce the mmap flag rules and convert affected drivers,
   removing ambiguous tests shared by driver mappings and ordinary
   memory.

 - "support kselftest on nommu platform" (Hajime Tazaki):

   Add opt-in mmap and mremap tests for NOMMU systems. Teach the runner
   to avoid its fork-dependent timeout command and document the build
   and runtime requirements.

 - "mm/collapse: separate a collapse from its callers" (Kiryl
   Shutsemau):

   Separate huge-page collapse from caller policy. Replace khugepaged
   identity checks with explicit permissions, and separate scanning from
   collapse with the mmap_lock drop in one place.

 - "mm: implement and use vma_has_anon_rmap(), silence KCSAN" (Lorenzo
   Stoakes):

   Provide a common helper for testing whether a VMA has anonymous
   reverse mappings. Document the locking rules, annotate intentional
   concurrent reads for KCSAN, and convert the core MM callers.

 - "mm/sparse: remove SECTION_MARKED_PRESENT and further cleanups"
   (David Hildenbrand):

   Remove SECTION_MARKED_PRESENT in favor of the early-section flag.
   Simplify sparse memory initialization, section metadata handling and
   related PFN validity checks.

 - "sh: remove NUMA and SPARSEMEM support" (Mike Rapoport):

   Remove SuperH NUMA and SPARSEMEM support. The extra memory banks have
   been unusable since the NO_BOOTMEM conversion, leaving only the code
   and data overhead.

 - "mm: Unify device DAX and HugeTLB vmemmap population paths" (Muchun
   Song):

   Unify the generic device DAX and HugeTLB vmemmap population paths and
   shared tail-page handling. Remove the duplicate DAX machinery while
   retaining the powerpc radix implementation.

 - "kselftest: mm: fix some failure of split_huge_page_test" (Yeoreum
   Yun):

   Fix huge-page split tests racing with khugepaged recollapse. Use
   pagemap and page flags instead of VMA-boundary assumptions which fail
   when glibc has already enabled THP.

 - "memcg: move memcgid refcount to objcg to unpin dying memcgs"
   (Bingfang Guo):

   Let dying memcgs be freed while swapped-out shmem still holds their
   IDs. Move ID references to reparentable objcgs, with the necessary
   swap accounting and RCU lifetime changes.

 - "mm/truncate: fix data loss when truncating straddling large folios"
   (Zhang Yi):

   Preserve out-of-range data when truncating straddling large folios.
   Fix a lookup race and split-failure handling, and handle minimum
   folio orders for the forthcoming ext4 iomap buffered I/O path.

 - "mm/damon: introduce damos quota goal target metric complement flag"
   (SJ Park):

   Let DAMOS quota goals use a metric's complement, so utilization can
   also express free-memory goals without adding separate metrics. Add
   the sysfs interface, documentation and tests.

 - "arm64/mm: Standardize printing for pgtable entries" (Anshuman
   Khandual):

   Use the generic formatter for arm64 page-table entries, ready for
   future wider entries. Move the safe-PTE-update check out of the
   header to avoid an include cycle.

 - "mm: kmsan: fix iounmap metadata teardown" (Dima Koziuk):

   Fix KMSAN metadata leaks on iounmap and failed ioremap allocations.
   Free backing pages before removing their mappings, and share the
   teardown with partial-allocation cleanup.

 - "mm/damon/core: preserve quota state when constructing schemes" (Karl
   Mehltretter):

   Preserve running DAMOS quota state while validating parameter
   updates. Even rejected updates could reset accounting and exceed the
   quota window; add tests for both accepted and rejected updates.

 - "mm/vmalloc: fix vmalloc_dump_obj VA lookup" (Ye Liu):

   Fix vmalloc_dump_obj() lookups for last-page addresses and
   allocations spanning vmap zones. These allocations were being missed
   in diagnostic output.

 - "mm: various (urgent?) fixes" (David Hildenbrand):

   Fix mmap charge leaks and hugetlb use-after-free, wrong-address
   unmapping, stuck locks and endless faults. Also preserve reservations
   on failed mremap and handle stale userfaultfd bits.

 - "maple_tree: fix maple_range_64 crashes in RCU mode" (Dimitris
   Charisis):

   Fix pointer and metadata confusion during RCU destruction of
   maple_range_64 nodes, avoiding double frees and invalid accesses. Add
   a regression test; no in-tree user currently uses this combination.

 - "mm: fix hugetlb NR_HUGETLB accounting on folio migration" (Hongfu
   Li):

   Fix hugetlb migration and preallocation accounting so /proc/vmstat
   retains the correct count and memory.numa_stat follows the folio to
   its new node.

 - "mm/damon: fix a minor bug, clean code, and add a test" (SJ Park):

   Fix 32-bit DAMON age overflow which made old regions look young.
   Share hugetlb folio acquisition code and add a regression test for
   the previously fixed last-region skipping bug.

 - "mm/damon/core: cleanup code, reduce stack usage, and add kunit" (SJ
   Park):

   Reduce kdamond stack usage and remove unused enums. Add deterministic
   PSI quota-goal tests which do not depend on the machine's current
   memory pressure.

 - "mm/damon: fix the temporal goal tuner's size quota conversion"
   (Donggeun Yoo):

   Bound the temporal tuner's quota conversion to prevent overflow and
   zero effective quotas, which could stop schemes making progress. Add
   boundary tests.

 - "Don't use GFP_DMA when calling dma_alloc_coherent" (Baoquan He):

   Remove redundant GFP_DMA flags from coherent DMA allocation calls.
   The DMA API already selects the zone from device limits and ignores
   the caller's flag.

 - "kselftest: mm: fix intermittent failure khugepaged test" (Yeoreum
   Yun):

   Propagate child-process failures in the khugepaged tests and prevent
   background collapse from racing their checks. This removes false
   passes and intermittent failures.

 - "MAINTAINERS: cover all hugetlb headers under HUGETLB SUBSYSTEM"
   (Enze Li):

   Cover all hugetlb headers in MAINTAINERS so get_maintainer.pl finds
   the right maintainers. Also label the closing hugetlb_cgroup.h
   include guard.

Summary of the 65 singletons in this merge:

  The singletons include a few worthwhile performance fixes. Avoiding
  unnecessary reverse-map tree updates gave a reported 15.9% improvement
  in UnixBench's execl test on a 192-core x86 system. A reclaim retry
  fix stops defrag_mode from spinning under memory.low protection; a
  reported file-creation stress test ran 5.7 times faster, with far less
  memory pressure. Narrower hugetlb invalidations also spare KVM guests
  needless refaults: the reported Redis-in-VM P99 QPS penalty while
  punching holes fell from 7.09% to 1.45%.

  Several fixes prevent lost data or corrupted memory. Lazyfree
  huge-page races with mremap()/munmap() could lose data or access freed
  memory, and MADV_COLD could lose a concurrent write's dirty bit.
  Another fix prevents stale migration entries from outliving large
  folios. On filesystems with blocks smaller than a page, extending a
  file by 4 GiB or more could expose bytes written past the old EOF
  through mmap instead of zeroes. That is fixed, along with
  use-after-free races in PAGEMAP_SCAN during process exit and in
  memory-cgroup accounting on PREEMPT_RT kernels.

  Other fixes stop UFFDIO_MOVE spinning forever on pinned large folios,
  which could wedge other memory operations, and stop mremap() leaking
  commit charges until allocations fail under strict overcommit. A
  further fix keeps userfaultfd tracking intact on neighboring mappings.
  NUMA binding no longer prevents long-term pins when the chosen node
  has only movable memory, fixing QEMU/VFIO startup and io_uring buffer
  registration failures. MGLRU also gets a fix for early-boot crashes
  with memory cgroups disabled at boot, notably in small crash kernels.

* tag 'mm-stable-2026-10-25-19-27' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (213 commits)
  mm: multi-gen LRU: fix NULL lruvec->pgdat deref with memcg disabled on cmdline
  mm/page_counter: use WRITE_ONCE() for emin/elow when parent is the root
  mm/memcontrol: publish null pointer before dropping css reference
  test_maple_tree: test maple_range_64 node in RCU mode
  maple_tree: fix maple_range_64 crashes in RCU mode
  mm/vma: avoid broken uffd merge on mremap
  tools/testing/shared: catch a failed posix_memalign()
  mm/damon/core: remove unreachable damos charge_{target,addr}_from
  mm/shrinker: allocate shrinker_info_unit from a dedicated kmem_cache
  riscv: mm: exclude invalid THP PMDs from page table check
  mm/damon/core: filter out damos address filter-split failed region
  fs/proc/task_mmu: pin mm_users in do_pagemap_scan()
  mm/mempolicy: apply bind policies against the scoped allocation zone
  mm/vmscan: reclaim every zone in per-node proactive reclaim
  mm/mremap: correctly uncharge accountable VMAs in error path
  mm/mremap: populate calculated fields in vrm state correctly
  MAINTAINERS: add an entry for MEMORY MANAGEMENT - MEMORY MAP
  mm: bdi: reset min_ratio after the sysfs attributes are gone
  mm/page_vma_mapped: continue past nonmatching huge PMDs
  selftests/mm: skip hugetlb cgroup v2 tests without the needed controllers
  ...

8 files changed, 20 insertions, 21 deletions

diff --git a/kernel/bpf/arena.c b/kernel/bpf/arena.c
index 868589f07330..3c61c181a6fa 100644
--- a/kernel/bpf/arena.c
+++ b/kernel/bpf/arena.c
@@ -692,8 +692,9 @@ static int arena_map_mmap(struct bpf_map *map, struct vm_area_struct *vma)
 	 * clears VM_MAYEXEC. Set VM_DONTEXPAND to avoid potential change
 	 * of user_vm_start. Set VM_DONTCOPY to prevent arena VMA from
 	 * being copied into the child process on fork.
+	 * This is a kernel page so set VM_MIXEDMAP.
 	 */
-	vm_flags_set(vma, VM_DONTEXPAND | VM_DONTCOPY);
+	vm_flags_set(vma, VM_MIXEDMAP | VM_DONTEXPAND | VM_DONTCOPY);
 	vma->vm_ops = &arena_vm_ops;
 	return 0;
 }
diff --git a/kernel/configs/debug.config b/kernel/configs/debug.config
index 307c97ac5fa9..ac878669c193 100644
--- a/kernel/configs/debug.config
+++ b/kernel/configs/debug.config
@@ -50,7 +50,7 @@ CONFIG_DEBUG_NET=y
 # CONFIG_DEBUG_PAGEALLOC is not set
 # CONFIG_DEBUG_KMEMLEAK_DEFAULT_OFF is not set
 # CONFIG_DEBUG_RODATA_TEST is not set
-# CONFIG_DEBUG_WX is not set
+# CONFIG_CHECK_WX is not set
 # CONFIG_KFENCE is not set
 # CONFIG_PAGE_POISONING is not set
 # CONFIG_SLUB_STATS is not set
diff --git a/kernel/events/core.c b/kernel/events/core.c
index f36a3bbaa33c..457d75ea7142 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -9927,7 +9927,7 @@ static void perf_event_mmap_event(struct perf_mmap_event *mmap_event)
 
 	if (vma->vm_flags & VM_LOCKED)
 		flags |= MAP_LOCKED;
-	if (is_vm_hugetlb_page(vma))
+	if (vma_is_hugetlb(vma))
 		flags |= MAP_HUGETLB;
 
 	if (file) {
diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
index 3192806eebfe..caf444762a27 100644
--- a/kernel/events/uprobes.c
+++ b/kernel/events/uprobes.c
@@ -1726,8 +1726,8 @@ static int xol_add_vma(struct mm_struct *mm, struct xol_area *area)
 	}
 
 	vma = _install_special_mapping(mm, area->vaddr, PAGE_SIZE,
-				VM_EXEC|VM_MAYEXEC|VM_DONTCOPY|VM_IO|
-				VM_SEALED_SYSMAP,
+				VM_EXEC|VM_MAYEXEC|VM_DONTCOPY|
+				VM_MIXEDMAP|VM_SEALED_SYSMAP,
 				&xol_mapping);
 	if (IS_ERR(vma)) {
 		ret = PTR_ERR(vma);
diff --git a/kernel/power/user.c b/kernel/power/user.c
index d0fcfba7ac23..6e4f40e49319 100644
--- a/kernel/power/user.c
+++ b/kernel/power/user.c
@@ -218,6 +218,7 @@ static int snapshot_set_swap_area(struct snapshot_data *data,
 {
 	sector_t offset;
 	dev_t swdev;
+	int new_type;
 
 	if (swsusp_swap_in_use())
 		return -EPERM;
@@ -238,19 +239,11 @@ static int snapshot_set_swap_area(struct snapshot_data *data,
 		offset = swap_area.offset;
 	}
 
-	/*
-	 * Unpin the swap device if a swap area was already
-	 * set by SNAPSHOT_SET_SWAP_AREA.
-	 */
-	unpin_hibernation_swap_type(data->swap);
+	new_type = repin_hibernation_swap_type(data->swap, swdev, offset);
+	if (new_type < 0)
+		return new_type;
 
-	/*
-	 * User space encodes device types as two-byte values,
-	 * so we need to recode them
-	 */
-	data->swap = pin_hibernation_swap_type(swdev, offset);
-	if (data->swap < 0)
-		return swdev ? -ENODEV : -EINVAL;
+	data->swap = new_type;
 	data->dev = swdev;
 	return 0;
 }
diff --git a/kernel/resource.c b/kernel/resource.c
index cfc1a00e86aa..0c315c917fbb 100644
--- a/kernel/resource.c
+++ b/kernel/resource.c
@@ -1695,10 +1695,15 @@ int devm_request_resource(struct device *dev, struct resource *root,
 
 	*ptr = new;
 
-	conflict = request_resource_conflict(root, new);
-	if (conflict) {
+	/* Report a conflict while the lock still keeps it in the tree. */
+	write_lock(&resource_lock);
+	conflict = __request_resource(root, new);
+	if (conflict)
 		dev_err(dev, "resource collision: %pR conflicts with %s %pR\n",
 			new, conflict->name, conflict);
+	write_unlock(&resource_lock);
+
+	if (conflict) {
 		devres_free(ptr);
 		return -EBUSY;
 	}
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index f77e7226693b..cfc982205b98 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -22,7 +22,6 @@
  */
 #include <linux/energy_model.h>
 #include <linux/mmap_lock.h>
-#include <linux/hugetlb_inline.h>
 #include <linux/jiffies.h>
 #include <linux/math.h>
 #include <linux/mm_api.h>
@@ -4364,7 +4363,7 @@ retry_pids:
 
 	for (; vma; vma = vma_next(&vmi)) {
 		if (!vma_migratable(vma) || !vma_policy_mof(vma) ||
-			is_vm_hugetlb_page(vma) || (vma->vm_flags & VM_MIXEDMAP)) {
+			vma_is_hugetlb(vma) || !vma_is_mm_managed(vma)) {
 			trace_sched_skip_vma_numa(mm, vma, NUMAB_SKIP_UNSUITABLE);
 			continue;
 		}
diff --git a/kernel/vmcore_info.c b/kernel/vmcore_info.c
index 5a417f8a922a..7833a36064a8 100644
--- a/kernel/vmcore_info.c
+++ b/kernel/vmcore_info.c
@@ -182,6 +182,7 @@ static int __init crash_save_vmcoreinfo_init(void)
 	VMCOREINFO_STRUCT_SIZE(mem_section);
 	VMCOREINFO_OFFSET(mem_section, section_mem_map);
 	VMCOREINFO_NUMBER(SECTION_SIZE_BITS);
+	VMCOREINFO_NUMBER(SECTION_HAS_MEM_MAP);
 	VMCOREINFO_NUMBER(MAX_PHYSMEM_BITS);
 #endif
 	VMCOREINFO_STRUCT_SIZE(page);