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authorLinus Torvalds <torvalds@linux-foundation.org>2023-01-17 03:36:39 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2023-01-17 03:36:39 +0300
commit6e50979a9c87371fdb85d16058f9b5cb40751501 (patch)
tree170c0418d6c1b14d8b1677bdc4bf799339b04129 /mm
parentd532dd102151cc69fcd00b13e5a9689b23c0c8d9 (diff)
parent19fa92fb72f8bc542f1673862058f3b078114004 (diff)
downloadlinux-6e50979a9c87371fdb85d16058f9b5cb40751501.tar.xz
Merge tag 'mm-hotfixes-stable-2023-01-16-15-23' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull misc hotfixes from Andrew Morton: "21 hotfixes. Thirteen of these address pre-6.1 issues and hence have the cc:stable tag" * tag 'mm-hotfixes-stable-2023-01-16-15-23' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (21 commits) init/Kconfig: fix typo (usafe -> unsafe) nommu: fix split_vma() map_count error nommu: fix do_munmap() error path nommu: fix memory leak in do_mmap() error path MAINTAINERS: update Robert Foss' email address proc: fix PIE proc-empty-vm, proc-pid-vm tests mm: update mmap_sem comments to refer to mmap_lock include/linux/mm: fix release_pages_arg kernel doc comment lib/win_minmax: use /* notation for regular comments kasan: mark kasan_kunit_executing as static nilfs2: fix general protection fault in nilfs_btree_insert() Docs/admin-guide/mm/zswap: remove zsmalloc's lack of writeback warning mm/hugetlb: pre-allocate pgtable pages for uffd wr-protects hugetlb: unshare some PMDs when splitting VMAs mm: fix vma->anon_name memory leak for anonymous shmem VMAs mm/shmem: restore SHMEM_HUGE_DENY precedence over MADV_COLLAPSE mm/MADV_COLLAPSE: don't expand collapse when vm_end is past requested end mm/userfaultfd: enable writenotify while userfaultfd-wp is enabled for a VMA mm/khugepaged: fix collapse_pte_mapped_thp() to allow anon_vma mm/hugetlb: fix uffd-wp handling for migration entries in hugetlb_change_protection() ...
Diffstat (limited to 'mm')
-rw-r--r--mm/hugetlb.c99
-rw-r--r--mm/kasan/report.c2
-rw-r--r--mm/khugepaged.c16
-rw-r--r--mm/madvise.c2
-rw-r--r--mm/mmap.c8
-rw-r--r--mm/nommu.c9
-rw-r--r--mm/shmem.c6
7 files changed, 87 insertions, 55 deletions
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index db895230ee7e..7fcdb98c9e68 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -94,6 +94,8 @@ static int hugetlb_acct_memory(struct hstate *h, long delta);
static void hugetlb_vma_lock_free(struct vm_area_struct *vma);
static void hugetlb_vma_lock_alloc(struct vm_area_struct *vma);
static void __hugetlb_vma_unlock_write_free(struct vm_area_struct *vma);
+static void hugetlb_unshare_pmds(struct vm_area_struct *vma,
+ unsigned long start, unsigned long end);
static inline bool subpool_is_free(struct hugepage_subpool *spool)
{
@@ -1181,7 +1183,7 @@ void hugetlb_dup_vma_private(struct vm_area_struct *vma)
/*
* Reset and decrement one ref on hugepage private reservation.
- * Called with mm->mmap_sem writer semaphore held.
+ * Called with mm->mmap_lock writer semaphore held.
* This function should be only used by move_vma() and operate on
* same sized vma. It should never come here with last ref on the
* reservation.
@@ -4834,6 +4836,25 @@ static int hugetlb_vm_op_split(struct vm_area_struct *vma, unsigned long addr)
{
if (addr & ~(huge_page_mask(hstate_vma(vma))))
return -EINVAL;
+
+ /*
+ * PMD sharing is only possible for PUD_SIZE-aligned address ranges
+ * in HugeTLB VMAs. If we will lose PUD_SIZE alignment due to this
+ * split, unshare PMDs in the PUD_SIZE interval surrounding addr now.
+ */
+ if (addr & ~PUD_MASK) {
+ /*
+ * hugetlb_vm_op_split is called right before we attempt to
+ * split the VMA. We will need to unshare PMDs in the old and
+ * new VMAs, so let's unshare before we split.
+ */
+ unsigned long floor = addr & PUD_MASK;
+ unsigned long ceil = floor + PUD_SIZE;
+
+ if (floor >= vma->vm_start && ceil <= vma->vm_end)
+ hugetlb_unshare_pmds(vma, floor, ceil);
+ }
+
return 0;
}
@@ -5131,7 +5152,7 @@ static void move_huge_pte(struct vm_area_struct *vma, unsigned long old_addr,
/*
* We don't have to worry about the ordering of src and dst ptlocks
- * because exclusive mmap_sem (or the i_mmap_lock) prevents deadlock.
+ * because exclusive mmap_lock (or the i_mmap_lock) prevents deadlock.
*/
if (src_ptl != dst_ptl)
spin_lock_nested(src_ptl, SINGLE_DEPTH_NESTING);
@@ -6639,8 +6660,17 @@ unsigned long hugetlb_change_protection(struct vm_area_struct *vma,
spinlock_t *ptl;
ptep = huge_pte_offset(mm, address, psize);
if (!ptep) {
- address |= last_addr_mask;
- continue;
+ if (!uffd_wp) {
+ address |= last_addr_mask;
+ continue;
+ }
+ /*
+ * Userfaultfd wr-protect requires pgtable
+ * pre-allocations to install pte markers.
+ */
+ ptep = huge_pte_alloc(mm, vma, address, psize);
+ if (!ptep)
+ break;
}
ptl = huge_pte_lock(h, mm, ptep);
if (huge_pmd_unshare(mm, vma, address, ptep)) {
@@ -6658,16 +6688,13 @@ unsigned long hugetlb_change_protection(struct vm_area_struct *vma,
}
pte = huge_ptep_get(ptep);
if (unlikely(is_hugetlb_entry_hwpoisoned(pte))) {
- spin_unlock(ptl);
- continue;
- }
- if (unlikely(is_hugetlb_entry_migration(pte))) {
+ /* Nothing to do. */
+ } else if (unlikely(is_hugetlb_entry_migration(pte))) {
swp_entry_t entry = pte_to_swp_entry(pte);
struct page *page = pfn_swap_entry_to_page(entry);
+ pte_t newpte = pte;
- if (!is_readable_migration_entry(entry)) {
- pte_t newpte;
-
+ if (is_writable_migration_entry(entry)) {
if (PageAnon(page))
entry = make_readable_exclusive_migration_entry(
swp_offset(entry));
@@ -6675,25 +6702,22 @@ unsigned long hugetlb_change_protection(struct vm_area_struct *vma,
entry = make_readable_migration_entry(
swp_offset(entry));
newpte = swp_entry_to_pte(entry);
- if (uffd_wp)
- newpte = pte_swp_mkuffd_wp(newpte);
- else if (uffd_wp_resolve)
- newpte = pte_swp_clear_uffd_wp(newpte);
- set_huge_pte_at(mm, address, ptep, newpte);
pages++;
}
- spin_unlock(ptl);
- continue;
- }
- if (unlikely(pte_marker_uffd_wp(pte))) {
- /*
- * This is changing a non-present pte into a none pte,
- * no need for huge_ptep_modify_prot_start/commit().
- */
+
+ if (uffd_wp)
+ newpte = pte_swp_mkuffd_wp(newpte);
+ else if (uffd_wp_resolve)
+ newpte = pte_swp_clear_uffd_wp(newpte);
+ if (!pte_same(pte, newpte))
+ set_huge_pte_at(mm, address, ptep, newpte);
+ } else if (unlikely(is_pte_marker(pte))) {
+ /* No other markers apply for now. */
+ WARN_ON_ONCE(!pte_marker_uffd_wp(pte));
if (uffd_wp_resolve)
+ /* Safe to modify directly (non-present->none). */
huge_pte_clear(mm, address, ptep, psize);
- }
- if (!huge_pte_none(pte)) {
+ } else if (!huge_pte_none(pte)) {
pte_t old_pte;
unsigned int shift = huge_page_shift(hstate_vma(vma));
@@ -7328,26 +7352,21 @@ void move_hugetlb_state(struct folio *old_folio, struct folio *new_folio, int re
}
}
-/*
- * This function will unconditionally remove all the shared pmd pgtable entries
- * within the specific vma for a hugetlbfs memory range.
- */
-void hugetlb_unshare_all_pmds(struct vm_area_struct *vma)
+static void hugetlb_unshare_pmds(struct vm_area_struct *vma,
+ unsigned long start,
+ unsigned long end)
{
struct hstate *h = hstate_vma(vma);
unsigned long sz = huge_page_size(h);
struct mm_struct *mm = vma->vm_mm;
struct mmu_notifier_range range;
- unsigned long address, start, end;
+ unsigned long address;
spinlock_t *ptl;
pte_t *ptep;
if (!(vma->vm_flags & VM_MAYSHARE))
return;
- start = ALIGN(vma->vm_start, PUD_SIZE);
- end = ALIGN_DOWN(vma->vm_end, PUD_SIZE);
-
if (start >= end)
return;
@@ -7379,6 +7398,16 @@ void hugetlb_unshare_all_pmds(struct vm_area_struct *vma)
mmu_notifier_invalidate_range_end(&range);
}
+/*
+ * This function will unconditionally remove all the shared pmd pgtable entries
+ * within the specific vma for a hugetlbfs memory range.
+ */
+void hugetlb_unshare_all_pmds(struct vm_area_struct *vma)
+{
+ hugetlb_unshare_pmds(vma, ALIGN(vma->vm_start, PUD_SIZE),
+ ALIGN_DOWN(vma->vm_end, PUD_SIZE));
+}
+
#ifdef CONFIG_CMA
static bool cma_reserve_called __initdata;
diff --git a/mm/kasan/report.c b/mm/kasan/report.c
index 1d02757e90a3..22598b20c7b7 100644
--- a/mm/kasan/report.c
+++ b/mm/kasan/report.c
@@ -119,7 +119,7 @@ EXPORT_SYMBOL_GPL(kasan_restore_multi_shot);
* Whether the KASAN KUnit test suite is currently being executed.
* Updated in kasan_test.c.
*/
-bool kasan_kunit_executing;
+static bool kasan_kunit_executing;
void kasan_kunit_test_suite_start(void)
{
diff --git a/mm/khugepaged.c b/mm/khugepaged.c
index 5cb401aa2b9d..79be13133322 100644
--- a/mm/khugepaged.c
+++ b/mm/khugepaged.c
@@ -1460,14 +1460,6 @@ int collapse_pte_mapped_thp(struct mm_struct *mm, unsigned long addr,
if (!hugepage_vma_check(vma, vma->vm_flags, false, false, false))
return SCAN_VMA_CHECK;
- /*
- * Symmetry with retract_page_tables(): Exclude MAP_PRIVATE mappings
- * that got written to. Without this, we'd have to also lock the
- * anon_vma if one exists.
- */
- if (vma->anon_vma)
- return SCAN_VMA_CHECK;
-
/* Keep pmd pgtable for uffd-wp; see comment in retract_page_tables() */
if (userfaultfd_wp(vma))
return SCAN_PTE_UFFD_WP;
@@ -1567,8 +1559,14 @@ int collapse_pte_mapped_thp(struct mm_struct *mm, unsigned long addr,
}
/* step 4: remove pte entries */
+ /* we make no change to anon, but protect concurrent anon page lookup */
+ if (vma->anon_vma)
+ anon_vma_lock_write(vma->anon_vma);
+
collapse_and_free_pmd(mm, vma, haddr, pmd);
+ if (vma->anon_vma)
+ anon_vma_unlock_write(vma->anon_vma);
i_mmap_unlock_write(vma->vm_file->f_mapping);
maybe_install_pmd:
@@ -2649,7 +2647,7 @@ int madvise_collapse(struct vm_area_struct *vma, struct vm_area_struct **prev,
goto out_nolock;
}
- hend = vma->vm_end & HPAGE_PMD_MASK;
+ hend = min(hend, vma->vm_end & HPAGE_PMD_MASK);
}
mmap_assert_locked(mm);
memset(cc->node_load, 0, sizeof(cc->node_load));
diff --git a/mm/madvise.c b/mm/madvise.c
index a56a6d17e201..b6ea204d4e23 100644
--- a/mm/madvise.c
+++ b/mm/madvise.c
@@ -130,7 +130,7 @@ static int replace_anon_vma_name(struct vm_area_struct *vma,
#endif /* CONFIG_ANON_VMA_NAME */
/*
* Update the vm_flags on region of a vma, splitting it or merging it as
- * necessary. Must be called with mmap_sem held for writing;
+ * necessary. Must be called with mmap_lock held for writing;
* Caller should ensure anon_name stability by raising its refcount even when
* anon_name belongs to a valid vma because this function might free that vma.
*/
diff --git a/mm/mmap.c b/mm/mmap.c
index 87d929316d57..425a9349e610 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -1524,6 +1524,10 @@ int vma_wants_writenotify(struct vm_area_struct *vma, pgprot_t vm_page_prot)
if (vma_soft_dirty_enabled(vma) && !is_vm_hugetlb_page(vma))
return 1;
+ /* Do we need write faults for uffd-wp tracking? */
+ if (userfaultfd_wp(vma))
+ return 1;
+
/* Specialty mapping? */
if (vm_flags & VM_PFNMAP)
return 0;
@@ -2290,7 +2294,7 @@ static inline int munmap_sidetree(struct vm_area_struct *vma,
* @start: The aligned start address to munmap.
* @end: The aligned end address to munmap.
* @uf: The userfaultfd list_head
- * @downgrade: Set to true to attempt a write downgrade of the mmap_sem
+ * @downgrade: Set to true to attempt a write downgrade of the mmap_lock
*
* If @downgrade is true, check return code for potential release of the lock.
*/
@@ -2465,7 +2469,7 @@ map_count_exceeded:
* @len: The length of the range to munmap
* @uf: The userfaultfd list_head
* @downgrade: set to true if the user wants to attempt to write_downgrade the
- * mmap_sem
+ * mmap_lock
*
* This function takes a @mas that is either pointing to the previous VMA or set
* to MA_START and sets it up to remove the mapping(s). The @len will be
diff --git a/mm/nommu.c b/mm/nommu.c
index 214c70e1d059..5b83938ecb67 100644
--- a/mm/nommu.c
+++ b/mm/nommu.c
@@ -559,7 +559,6 @@ void vma_mas_remove(struct vm_area_struct *vma, struct ma_state *mas)
static void setup_vma_to_mm(struct vm_area_struct *vma, struct mm_struct *mm)
{
- mm->map_count++;
vma->vm_mm = mm;
/* add the VMA to the mapping */
@@ -587,6 +586,7 @@ static void mas_add_vma_to_mm(struct ma_state *mas, struct mm_struct *mm,
BUG_ON(!vma->vm_region);
setup_vma_to_mm(vma, mm);
+ mm->map_count++;
/* add the VMA to the tree */
vma_mas_store(vma, mas);
@@ -1240,6 +1240,7 @@ share:
error_just_free:
up_write(&nommu_region_sem);
error:
+ mas_destroy(&mas);
if (region->vm_file)
fput(region->vm_file);
kmem_cache_free(vm_region_jar, region);
@@ -1250,7 +1251,6 @@ error:
sharing_violation:
up_write(&nommu_region_sem);
- mas_destroy(&mas);
pr_warn("Attempt to share mismatched mappings\n");
ret = -EINVAL;
goto error;
@@ -1347,6 +1347,7 @@ int split_vma(struct mm_struct *mm, struct vm_area_struct *vma,
if (vma->vm_file)
return -ENOMEM;
+ mm = vma->vm_mm;
if (mm->map_count >= sysctl_max_map_count)
return -ENOMEM;
@@ -1398,6 +1399,7 @@ int split_vma(struct mm_struct *mm, struct vm_area_struct *vma,
mas_set_range(&mas, vma->vm_start, vma->vm_end - 1);
mas_store(&mas, vma);
vma_mas_store(new, &mas);
+ mm->map_count++;
return 0;
err_mas_preallocate:
@@ -1509,7 +1511,8 @@ int do_munmap(struct mm_struct *mm, unsigned long start, size_t len, struct list
erase_whole_vma:
if (delete_vma_from_mm(vma))
ret = -ENOMEM;
- delete_vma(mm, vma);
+ else
+ delete_vma(mm, vma);
return ret;
}
diff --git a/mm/shmem.c b/mm/shmem.c
index c301487be5fb..0005ab2c29af 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -478,12 +478,10 @@ bool shmem_is_huge(struct vm_area_struct *vma, struct inode *inode,
if (vma && ((vma->vm_flags & VM_NOHUGEPAGE) ||
test_bit(MMF_DISABLE_THP, &vma->vm_mm->flags)))
return false;
- if (shmem_huge_force)
- return true;
- if (shmem_huge == SHMEM_HUGE_FORCE)
- return true;
if (shmem_huge == SHMEM_HUGE_DENY)
return false;
+ if (shmem_huge_force || shmem_huge == SHMEM_HUGE_FORCE)
+ return true;
switch (SHMEM_SB(inode->i_sb)->huge) {
case SHMEM_HUGE_ALWAYS: