Merge tag 'mm-hotfixes-stable-2022-12-10-1' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull misc fixes from Andrew Morton:
 "Nine hotfixes.

  Six for MM, three for other areas. Four of these patches address
  post-6.0 issues"

* tag 'mm-hotfixes-stable-2022-12-10-1' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
  memcg: fix possible use-after-free in memcg_write_event_control()
  MAINTAINERS: update Muchun Song's email
  mm/gup: fix gup_pud_range() for dax
  mmap: fix do_brk_flags() modifying obviously incorrect VMAs
  mm/swap: fix SWP_PFN_BITS with CONFIG_PHYS_ADDR_T_64BIT on 32bit
  tmpfs: fix data loss from failed fallocate
  kselftests: cgroup: update kmem test precision tolerance
  mm: do not BUG_ON missing brk mapping, because userspace can unmap it
  mailmap: update Matti Vaittinen's email address

7 files changed, 29 insertions, 19 deletions

diff --git a/.mailmap b/.mailmap
index bbb6a077d227..2301c29ccf6d 100644
--- a/.mailmap
+++ b/.mailmap
@@ -287,6 +287,7 @@ Matthew Wilcox <willy@infradead.org> <willy@linux.intel.com>
 Matthew Wilcox <willy@infradead.org> <willy@parisc-linux.org>
 Matthias Fuchs <socketcan@esd.eu> <matthias.fuchs@esd.eu>
 Matthieu CASTET <castet.matthieu@free.fr>
+Matti Vaittinen <mazziesaccount@gmail.com> <matti.vaittinen@fi.rohmeurope.com>
 Matt Ranostay <matt.ranostay@konsulko.com> <matt@ranostay.consulting>
 Matt Ranostay <mranostay@gmail.com> Matthew Ranostay <mranostay@embeddedalley.com>
 Matt Ranostay <mranostay@gmail.com> <matt.ranostay@intel.com>
@@ -372,6 +373,8 @@ Ricardo Ribalda <ribalda@kernel.org> <ricardo.ribalda@gmail.com>
 Roman Gushchin <roman.gushchin@linux.dev> <guro@fb.com>
 Roman Gushchin <roman.gushchin@linux.dev> <guroan@gmail.com>
 Roman Gushchin <roman.gushchin@linux.dev> <klamm@yandex-team.ru>
+Muchun Song <muchun.song@linux.dev> <songmuchun@bytedance.com>
+Muchun Song <muchun.song@linux.dev> <smuchun@gmail.com>
 Ross Zwisler <zwisler@kernel.org> <ross.zwisler@linux.intel.com>
 Rudolf Marek <R.Marek@sh.cvut.cz>
 Rui Saraiva <rmps@joel.ist.utl.pt>
diff --git a/MAINTAINERS b/MAINTAINERS
index 1daadaa4d48b..886d3f69ee64 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -5299,7 +5299,7 @@ M:	Johannes Weiner <hannes@cmpxchg.org>
 M:	Michal Hocko <mhocko@kernel.org>
 M:	Roman Gushchin <roman.gushchin@linux.dev>
 M:	Shakeel Butt <shakeelb@google.com>
-R:	Muchun Song <songmuchun@bytedance.com>
+R:	Muchun Song <muchun.song@linux.dev>
 L:	cgroups@vger.kernel.org
 L:	linux-mm@kvack.org
 S:	Maintained
@@ -9439,7 +9439,7 @@ F:	drivers/net/ethernet/huawei/hinic/
 
 HUGETLB SUBSYSTEM
 M:	Mike Kravetz <mike.kravetz@oracle.com>
-M:	Muchun Song <songmuchun@bytedance.com>
+M:	Muchun Song <muchun.song@linux.dev>
 L:	linux-mm@kvack.org
 S:	Maintained
 F:	Documentation/ABI/testing/sysfs-kernel-mm-hugepages
diff --git a/include/linux/swapops.h b/include/linux/swapops.h
index 86b95ccb81bb..b07b277d6a16 100644
--- a/include/linux/swapops.h
+++ b/include/linux/swapops.h
@@ -33,11 +33,13 @@
  * can use the extra bits to store other information besides PFN.
  */
 #ifdef MAX_PHYSMEM_BITS
-#define SWP_PFN_BITS			(MAX_PHYSMEM_BITS - PAGE_SHIFT)
+#define SWP_PFN_BITS		(MAX_PHYSMEM_BITS - PAGE_SHIFT)
 #else  /* MAX_PHYSMEM_BITS */
-#define SWP_PFN_BITS			(BITS_PER_LONG - PAGE_SHIFT)
+#define SWP_PFN_BITS		min_t(int, \
+				      sizeof(phys_addr_t) * 8 - PAGE_SHIFT, \
+				      SWP_TYPE_SHIFT)
 #endif	/* MAX_PHYSMEM_BITS */
-#define SWP_PFN_MASK			(BIT(SWP_PFN_BITS) - 1)
+#define SWP_PFN_MASK		(BIT(SWP_PFN_BITS) - 1)
 
 /**
  * Migration swap entry specific bitfield definitions.  Layout:
diff --git a/mm/gup.c b/mm/gup.c
index fe195d47de74..3b7bc2c1fd44 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -2852,7 +2852,7 @@ static int gup_pud_range(p4d_t *p4dp, p4d_t p4d, unsigned long addr, unsigned lo
 		next = pud_addr_end(addr, end);
 		if (unlikely(!pud_present(pud)))
 			return 0;
-		if (unlikely(pud_huge(pud))) {
+		if (unlikely(pud_huge(pud) || pud_devmap(pud))) {
 			if (!gup_huge_pud(pud, pudp, addr, next, flags,
 					  pages, nr))
 				return 0;
diff --git a/mm/mmap.c b/mm/mmap.c
index a5eb2f175da0..54abd46e6007 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -226,8 +226,7 @@ SYSCALL_DEFINE1(brk, unsigned long, brk)
 		/* Search one past newbrk */
 		mas_set(&mas, newbrk);
 		brkvma = mas_find(&mas, oldbrk);
-		BUG_ON(brkvma == NULL);
-		if (brkvma->vm_start >= oldbrk)
+		if (!brkvma || brkvma->vm_start >= oldbrk)
 			goto out; /* mapping intersects with an existing non-brk vma. */
 		/*
 		 * mm->brk must be protected by write mmap_lock.
@@ -2946,9 +2945,9 @@ static int do_brk_flags(struct ma_state *mas, struct vm_area_struct *vma,
 	 * Expand the existing vma if possible; Note that singular lists do not
 	 * occur after forking, so the expand will only happen on new VMAs.
 	 */
-	if (vma &&
-	    (!vma->anon_vma || list_is_singular(&vma->anon_vma_chain)) &&
-	    ((vma->vm_flags & ~VM_SOFTDIRTY) == flags)) {
+	if (vma && vma->vm_end == addr && !vma_policy(vma) &&
+	    can_vma_merge_after(vma, flags, NULL, NULL,
+				addr >> PAGE_SHIFT, NULL_VM_UFFD_CTX, NULL)) {
 		mas_set_range(mas, vma->vm_start, addr + len - 1);
 		if (mas_preallocate(mas, vma, GFP_KERNEL))
 			return -ENOMEM;
@@ -3035,11 +3034,6 @@ int vm_brk_flags(unsigned long addr, unsigned long request, unsigned long flags)
 		goto munmap_failed;
 
 	vma = mas_prev(&mas, 0);
-	if (!vma || vma->vm_end != addr || vma_policy(vma) ||
-	    !can_vma_merge_after(vma, flags, NULL, NULL,
-				 addr >> PAGE_SHIFT, NULL_VM_UFFD_CTX, NULL))
-		vma = NULL;
-
 	ret = do_brk_flags(&mas, vma, addr, len, flags);
 	populate = ((mm->def_flags & VM_LOCKED) != 0);
 	mmap_write_unlock(mm);
diff --git a/mm/shmem.c b/mm/shmem.c
index c1d8b8a1aa3b..82911fefc2d5 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -948,6 +948,15 @@ static void shmem_undo_range(struct inode *inode, loff_t lstart, loff_t lend,
 		index++;
 	}
 
+	/*
+	 * When undoing a failed fallocate, we want none of the partial folio
+	 * zeroing and splitting below, but shall want to truncate the whole
+	 * folio when !uptodate indicates that it was added by this fallocate,
+	 * even when [lstart, lend] covers only a part of the folio.
+	 */
+	if (unfalloc)
+		goto whole_folios;
+
 	same_folio = (lstart >> PAGE_SHIFT) == (lend >> PAGE_SHIFT);
 	folio = shmem_get_partial_folio(inode, lstart >> PAGE_SHIFT);
 	if (folio) {
@@ -973,6 +982,8 @@ static void shmem_undo_range(struct inode *inode, loff_t lstart, loff_t lend,
 		folio_put(folio);
 	}
 
+whole_folios:
+
 	index = start;
 	while (index < end) {
 		cond_resched();
diff --git a/tools/testing/selftests/cgroup/test_kmem.c b/tools/testing/selftests/cgroup/test_kmem.c
index 22b31ebb3513..258ddc565deb 100644
--- a/tools/testing/selftests/cgroup/test_kmem.c
+++ b/tools/testing/selftests/cgroup/test_kmem.c
@@ -19,12 +19,12 @@
 
 
 /*
- * Memory cgroup charging is performed using percpu batches 32 pages
+ * Memory cgroup charging is performed using percpu batches 64 pages
  * big (look at MEMCG_CHARGE_BATCH), whereas memory.stat is exact. So
  * the maximum discrepancy between charge and vmstat entries is number
- * of cpus multiplied by 32 pages.
+ * of cpus multiplied by 64 pages.
  */
-#define MAX_VMSTAT_ERROR (4096 * 32 * get_nprocs())
+#define MAX_VMSTAT_ERROR (4096 * 64 * get_nprocs())
 
 
 static int alloc_dcache(const char *cgroup, void *arg)