2022-05-04 05:44:47

by Liam Howlett

[permalink] [raw]
Subject: [PATCH v9 67/69] mm: remove the vma linked list

From: "Liam R. Howlett" <[email protected]>

Replace any vm_next use with vma_find().

Update free_pgtables(), unmap_vmas(), and zap_page_range() to use the
maple tree.

Use the new free_pgtables() and unmap_vmas() in do_mas_align_munmap(). At
the same time, alter the loop to be more compact.

Now that free_pgtables() and unmap_vmas() take a maple tree as an
argument, rearrange do_mas_align_munmap() to use the new tree to hold the
vmas to remove.

Remove __vma_link_list() and __vma_unlink_list() as they are exclusively
used to update the linked list

Drop linked list update from __insert_vm_struct().

Rework validation of tree as it was depending on the linked list.

Signed-off-by: Liam R. Howlett <[email protected]>
---
include/linux/mm.h | 5 +-
include/linux/mm_types.h | 4 -
kernel/fork.c | 19 +-
mm/debug.c | 14 +-
mm/internal.h | 8 +-
mm/memory.c | 33 ++-
mm/mmap.c | 439 +++++++++++++++++----------------------
mm/nommu.c | 5 -
mm/util.c | 40 ----
9 files changed, 223 insertions(+), 344 deletions(-)

diff --git a/include/linux/mm.h b/include/linux/mm.h
index 0cc2cb692a78..f16bf2c017ab 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1867,8 +1867,9 @@ void zap_vma_ptes(struct vm_area_struct *vma, unsigned long address,
unsigned long size);
void zap_page_range(struct vm_area_struct *vma, unsigned long address,
unsigned long size);
-void unmap_vmas(struct mmu_gather *tlb, struct vm_area_struct *start_vma,
- unsigned long start, unsigned long end);
+void unmap_vmas(struct mmu_gather *tlb, struct maple_tree *mt,
+ struct vm_area_struct *start_vma, unsigned long start,
+ unsigned long end);

struct mmu_notifier_range;

diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h
index b844119387a3..bdc5d0a5e76d 100644
--- a/include/linux/mm_types.h
+++ b/include/linux/mm_types.h
@@ -398,8 +398,6 @@ struct vm_area_struct {
unsigned long vm_end; /* The first byte after our end address
within vm_mm. */

- /* linked list of VM areas per task, sorted by address */
- struct vm_area_struct *vm_next, *vm_prev;
struct mm_struct *vm_mm; /* The address space we belong to. */

/*
@@ -463,7 +461,6 @@ struct vm_area_struct {
struct kioctx_table;
struct mm_struct {
struct {
- struct vm_area_struct *mmap; /* list of VMAs */
struct maple_tree mm_mt;
#ifdef CONFIG_MMU
unsigned long (*get_unmapped_area) (struct file *filp,
@@ -478,7 +475,6 @@ struct mm_struct {
unsigned long mmap_compat_legacy_base;
#endif
unsigned long task_size; /* size of task vm space */
- unsigned long highest_vm_end; /* highest vma end address */
pgd_t * pgd;

#ifdef CONFIG_MEMBARRIER
diff --git a/kernel/fork.c b/kernel/fork.c
index 9fcbd0b5c0be..536dc3289734 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -474,7 +474,6 @@ struct vm_area_struct *vm_area_dup(struct vm_area_struct *orig)
*/
*new = data_race(*orig);
INIT_LIST_HEAD(&new->anon_vma_chain);
- new->vm_next = new->vm_prev = NULL;
dup_anon_vma_name(orig, new);
}
return new;
@@ -579,7 +578,7 @@ static void dup_mm_exe_file(struct mm_struct *mm, struct mm_struct *oldmm)
static __latent_entropy int dup_mmap(struct mm_struct *mm,
struct mm_struct *oldmm)
{
- struct vm_area_struct *mpnt, *tmp, *prev, **pprev;
+ struct vm_area_struct *mpnt, *tmp;
int retval;
unsigned long charge = 0;
MA_STATE(old_mas, &oldmm->mm_mt, 0, 0);
@@ -606,7 +605,6 @@ static __latent_entropy int dup_mmap(struct mm_struct *mm,
mm->exec_vm = oldmm->exec_vm;
mm->stack_vm = oldmm->stack_vm;

- pprev = &mm->mmap;
retval = ksm_fork(mm, oldmm);
if (retval)
goto out;
@@ -614,12 +612,6 @@ static __latent_entropy int dup_mmap(struct mm_struct *mm,
if (retval)
goto out;

- retval = mas_expected_entries(&mas, oldmm->map_count);
- if (retval)
- goto out;
-
- prev = NULL;
-
retval = mas_expected_entries(&mas, oldmm->map_count);
if (retval)
goto out;
@@ -691,14 +683,6 @@ static __latent_entropy int dup_mmap(struct mm_struct *mm,
if (is_vm_hugetlb_page(tmp))
reset_vma_resv_huge_pages(tmp);

- /*
- * Link in the new vma and copy the page table entries.
- */
- *pprev = tmp;
- pprev = &tmp->vm_next;
- tmp->vm_prev = prev;
- prev = tmp;
-
/* Link the vma into the MT */
mas.index = tmp->vm_start;
mas.last = tmp->vm_end - 1;
@@ -1115,7 +1099,6 @@ static void mm_init_uprobes_state(struct mm_struct *mm)
static struct mm_struct *mm_init(struct mm_struct *mm, struct task_struct *p,
struct user_namespace *user_ns)
{
- mm->mmap = NULL;
mt_init_flags(&mm->mm_mt, MM_MT_FLAGS);
mt_set_external_lock(&mm->mm_mt, &mm->mmap_lock);
atomic_set(&mm->mm_users, 1);
diff --git a/mm/debug.c b/mm/debug.c
index 2d625ca0e326..0fd15ba70d16 100644
--- a/mm/debug.c
+++ b/mm/debug.c
@@ -139,13 +139,11 @@ EXPORT_SYMBOL(dump_page);

void dump_vma(const struct vm_area_struct *vma)
{
- pr_emerg("vma %px start %px end %px\n"
- "next %px prev %px mm %px\n"
+ pr_emerg("vma %px start %px end %px mm %px\n"
"prot %lx anon_vma %px vm_ops %px\n"
"pgoff %lx file %px private_data %px\n"
"flags: %#lx(%pGv)\n",
- vma, (void *)vma->vm_start, (void *)vma->vm_end, vma->vm_next,
- vma->vm_prev, vma->vm_mm,
+ vma, (void *)vma->vm_start, (void *)vma->vm_end, vma->vm_mm,
(unsigned long)pgprot_val(vma->vm_page_prot),
vma->anon_vma, vma->vm_ops, vma->vm_pgoff,
vma->vm_file, vma->vm_private_data,
@@ -155,11 +153,11 @@ EXPORT_SYMBOL(dump_vma);

void dump_mm(const struct mm_struct *mm)
{
- pr_emerg("mm %px mmap %px task_size %lu\n"
+ pr_emerg("mm %px task_size %lu\n"
#ifdef CONFIG_MMU
"get_unmapped_area %px\n"
#endif
- "mmap_base %lu mmap_legacy_base %lu highest_vm_end %lu\n"
+ "mmap_base %lu mmap_legacy_base %lu\n"
"pgd %px mm_users %d mm_count %d pgtables_bytes %lu map_count %d\n"
"hiwater_rss %lx hiwater_vm %lx total_vm %lx locked_vm %lx\n"
"pinned_vm %llx data_vm %lx exec_vm %lx stack_vm %lx\n"
@@ -183,11 +181,11 @@ void dump_mm(const struct mm_struct *mm)
"tlb_flush_pending %d\n"
"def_flags: %#lx(%pGv)\n",

- mm, mm->mmap, mm->task_size,
+ mm, mm->task_size,
#ifdef CONFIG_MMU
mm->get_unmapped_area,
#endif
- mm->mmap_base, mm->mmap_legacy_base, mm->highest_vm_end,
+ mm->mmap_base, mm->mmap_legacy_base,
mm->pgd, atomic_read(&mm->mm_users),
atomic_read(&mm->mm_count),
mm_pgtables_bytes(mm),
diff --git a/mm/internal.h b/mm/internal.h
index ddd09245a6db..fe33cb47935b 100644
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -69,8 +69,9 @@ void folio_rotate_reclaimable(struct folio *folio);
bool __folio_end_writeback(struct folio *folio);
void deactivate_file_folio(struct folio *folio);

-void free_pgtables(struct mmu_gather *tlb, struct vm_area_struct *start_vma,
- unsigned long floor, unsigned long ceiling);
+void free_pgtables(struct mmu_gather *tlb, struct maple_tree *mt,
+ struct vm_area_struct *start_vma, unsigned long floor,
+ unsigned long ceiling);
void pmd_install(struct mm_struct *mm, pmd_t *pmd, pgtable_t *pte);

struct zap_details;
@@ -458,9 +459,6 @@ static inline bool is_data_mapping(vm_flags_t flags)
}

/* mm/util.c */
-void __vma_link_list(struct mm_struct *mm, struct vm_area_struct *vma,
- struct vm_area_struct *prev);
-void __vma_unlink_list(struct mm_struct *mm, struct vm_area_struct *vma);
struct anon_vma *folio_anon_vma(struct folio *folio);

#ifdef CONFIG_MMU
diff --git a/mm/memory.c b/mm/memory.c
index e873a6143181..9e5b3ab8f7c0 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -399,12 +399,21 @@ void free_pgd_range(struct mmu_gather *tlb,
} while (pgd++, addr = next, addr != end);
}

-void free_pgtables(struct mmu_gather *tlb, struct vm_area_struct *vma,
- unsigned long floor, unsigned long ceiling)
+void free_pgtables(struct mmu_gather *tlb, struct maple_tree *mt,
+ struct vm_area_struct *vma, unsigned long floor,
+ unsigned long ceiling)
{
- while (vma) {
- struct vm_area_struct *next = vma->vm_next;
+ MA_STATE(mas, mt, vma->vm_end, vma->vm_end);
+
+ do {
unsigned long addr = vma->vm_start;
+ struct vm_area_struct *next;
+
+ /*
+ * Note: USER_PGTABLES_CEILING may be passed as ceiling and may
+ * be 0. This will underflow and is okay.
+ */
+ next = mas_find(&mas, ceiling - 1);

/*
* Hide vma from rmap and truncate_pagecache before freeing
@@ -423,7 +432,7 @@ void free_pgtables(struct mmu_gather *tlb, struct vm_area_struct *vma,
while (next && next->vm_start <= vma->vm_end + PMD_SIZE
&& !is_vm_hugetlb_page(next)) {
vma = next;
- next = vma->vm_next;
+ next = mas_find(&mas, ceiling - 1);
unlink_anon_vmas(vma);
unlink_file_vma(vma);
}
@@ -431,7 +440,7 @@ void free_pgtables(struct mmu_gather *tlb, struct vm_area_struct *vma,
floor, next ? next->vm_start : ceiling);
}
vma = next;
- }
+ } while (vma);
}

void pmd_install(struct mm_struct *mm, pmd_t *pmd, pgtable_t *pte)
@@ -1632,17 +1641,19 @@ static void unmap_single_vma(struct mmu_gather *tlb,
* ensure that any thus-far unmapped pages are flushed before unmap_vmas()
* drops the lock and schedules.
*/
-void unmap_vmas(struct mmu_gather *tlb,
+void unmap_vmas(struct mmu_gather *tlb, struct maple_tree *mt,
struct vm_area_struct *vma, unsigned long start_addr,
unsigned long end_addr)
{
struct mmu_notifier_range range;
+ MA_STATE(mas, mt, vma->vm_end, vma->vm_end);

mmu_notifier_range_init(&range, MMU_NOTIFY_UNMAP, 0, vma, vma->vm_mm,
start_addr, end_addr);
mmu_notifier_invalidate_range_start(&range);
- for ( ; vma && vma->vm_start < end_addr; vma = vma->vm_next)
+ do {
unmap_single_vma(tlb, vma, start_addr, end_addr, NULL);
+ } while ((vma = mas_find(&mas, end_addr - 1)) != NULL);
mmu_notifier_invalidate_range_end(&range);
}

@@ -1657,8 +1668,11 @@ void unmap_vmas(struct mmu_gather *tlb,
void zap_page_range(struct vm_area_struct *vma, unsigned long start,
unsigned long size)
{
+ struct maple_tree *mt = &vma->vm_mm->mm_mt;
+ unsigned long end = start + size;
struct mmu_notifier_range range;
struct mmu_gather tlb;
+ MA_STATE(mas, mt, vma->vm_end, vma->vm_end);

lru_add_drain();
mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, vma, vma->vm_mm,
@@ -1666,8 +1680,9 @@ void zap_page_range(struct vm_area_struct *vma, unsigned long start,
tlb_gather_mmu(&tlb, vma->vm_mm);
update_hiwater_rss(vma->vm_mm);
mmu_notifier_invalidate_range_start(&range);
- for ( ; vma && vma->vm_start < range.end; vma = vma->vm_next)
+ do {
unmap_single_vma(&tlb, vma, start, range.end, NULL);
+ } while ((vma = mas_find(&mas, end - 1)) != NULL);
mmu_notifier_invalidate_range_end(&range);
tlb_finish_mmu(&tlb);
}
diff --git a/mm/mmap.c b/mm/mmap.c
index 572a2a474b49..7704c879bc6d 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -75,9 +75,10 @@ int mmap_rnd_compat_bits __read_mostly = CONFIG_ARCH_MMAP_RND_COMPAT_BITS;
static bool ignore_rlimit_data;
core_param(ignore_rlimit_data, ignore_rlimit_data, bool, 0644);

-static void unmap_region(struct mm_struct *mm,
+static void unmap_region(struct mm_struct *mm, struct maple_tree *mt,
struct vm_area_struct *vma, struct vm_area_struct *prev,
- unsigned long start, unsigned long end);
+ struct vm_area_struct *next, unsigned long start,
+ unsigned long end);

/* description of effects of mapping type and prot in current implementation.
* this is due to the limited x86 page protection hardware. The expected
@@ -177,12 +178,10 @@ void unlink_file_vma(struct vm_area_struct *vma)
}

/*
- * Close a vm structure and free it, returning the next.
+ * Close a vm structure and free it.
*/
-static struct vm_area_struct *remove_vma(struct vm_area_struct *vma)
+static void remove_vma(struct vm_area_struct *vma)
{
- struct vm_area_struct *next = vma->vm_next;
-
might_sleep();
if (vma->vm_ops && vma->vm_ops->close)
vma->vm_ops->close(vma);
@@ -190,7 +189,6 @@ static struct vm_area_struct *remove_vma(struct vm_area_struct *vma)
fput(vma->vm_file);
mpol_put(vma_policy(vma));
vm_area_free(vma);
- return next;
}

/*
@@ -215,8 +213,7 @@ static int do_brk_munmap(struct ma_state *mas, struct vm_area_struct *vma,
unsigned long newbrk, unsigned long oldbrk,
struct list_head *uf);
static int do_brk_flags(struct ma_state *mas, struct vm_area_struct *brkvma,
- unsigned long addr, unsigned long request,
- unsigned long flags);
+ unsigned long addr, unsigned long request, unsigned long flags);
SYSCALL_DEFINE1(brk, unsigned long, brk)
{
unsigned long newbrk, oldbrk, origbrk;
@@ -285,7 +282,6 @@ SYSCALL_DEFINE1(brk, unsigned long, brk)
* before calling do_brk_munmap().
*/
mm->brk = brk;
- mas.last = oldbrk - 1;
ret = do_brk_munmap(&mas, brkvma, newbrk, oldbrk, &uf);
if (ret == 1) {
downgraded = true;
@@ -340,42 +336,20 @@ extern void mt_dump(const struct maple_tree *mt);
static void validate_mm_mt(struct mm_struct *mm)
{
struct maple_tree *mt = &mm->mm_mt;
- struct vm_area_struct *vma_mt, *vma = mm->mmap;
+ struct vm_area_struct *vma_mt;

MA_STATE(mas, mt, 0, 0);
- mas_for_each(&mas, vma_mt, ULONG_MAX) {
- if (xa_is_zero(vma_mt))
- continue;
-
- if (!vma)
- break;

- if ((vma != vma_mt) ||
- (vma->vm_start != vma_mt->vm_start) ||
- (vma->vm_end != vma_mt->vm_end) ||
- (vma->vm_start != mas.index) ||
- (vma->vm_end - 1 != mas.last)) {
+ mas_for_each(&mas, vma_mt, ULONG_MAX) {
+ if ((vma_mt->vm_start != mas.index) ||
+ (vma_mt->vm_end - 1 != mas.last)) {
pr_emerg("issue in %s\n", current->comm);
dump_stack();
dump_vma(vma_mt);
- pr_emerg("and vm_next\n");
- dump_vma(vma->vm_next);
pr_emerg("mt piv: %px %lu - %lu\n", vma_mt,
mas.index, mas.last);
pr_emerg("mt vma: %px %lu - %lu\n", vma_mt,
vma_mt->vm_start, vma_mt->vm_end);
- if (vma->vm_prev) {
- pr_emerg("ll prev: %px %lu - %lu\n",
- vma->vm_prev, vma->vm_prev->vm_start,
- vma->vm_prev->vm_end);
- }
- pr_emerg("ll vma: %px %lu - %lu\n", vma,
- vma->vm_start, vma->vm_end);
- if (vma->vm_next) {
- pr_emerg("ll next: %px %lu - %lu\n",
- vma->vm_next, vma->vm_next->vm_start,
- vma->vm_next->vm_end);
- }

mt_dump(mas.tree);
if (vma_mt->vm_end != mas.last + 1) {
@@ -392,11 +366,7 @@ static void validate_mm_mt(struct mm_struct *mm)
}
VM_BUG_ON_MM(vma_mt->vm_start != mas.index, mm);
}
- VM_BUG_ON(vma != vma_mt);
- vma = vma->vm_next;
-
}
- VM_BUG_ON(vma);
mt_validate(&mm->mm_mt);
}

@@ -404,12 +374,12 @@ static void validate_mm(struct mm_struct *mm)
{
int bug = 0;
int i = 0;
- unsigned long highest_address = 0;
- struct vm_area_struct *vma = mm->mmap;
+ struct vm_area_struct *vma;
+ MA_STATE(mas, &mm->mm_mt, 0, 0);

validate_mm_mt(mm);

- while (vma) {
+ mas_for_each(&mas, vma, ULONG_MAX) {
#ifdef CONFIG_DEBUG_VM_RB
struct anon_vma *anon_vma = vma->anon_vma;
struct anon_vma_chain *avc;
@@ -421,18 +391,10 @@ static void validate_mm(struct mm_struct *mm)
anon_vma_unlock_read(anon_vma);
}
#endif
-
- highest_address = vm_end_gap(vma);
- vma = vma->vm_next;
i++;
}
if (i != mm->map_count) {
- pr_emerg("map_count %d vm_next %d\n", mm->map_count, i);
- bug = 1;
- }
- if (highest_address != mm->highest_vm_end) {
- pr_emerg("mm->highest_vm_end %lx, found %lx\n",
- mm->highest_vm_end, highest_address);
+ pr_emerg("map_count %d mas_for_each %d\n", mm->map_count, i);
bug = 1;
}
VM_BUG_ON_MM(bug, mm);
@@ -492,29 +454,13 @@ bool range_has_overlap(struct mm_struct *mm, unsigned long start,
struct vm_area_struct *existing;

MA_STATE(mas, &mm->mm_mt, start, start);
+ rcu_read_lock();
existing = mas_find(&mas, end - 1);
*pprev = mas_prev(&mas, 0);
+ rcu_read_unlock();
return existing ? true : false;
}

-/*
- * __vma_next() - Get the next VMA.
- * @mm: The mm_struct.
- * @vma: The current vma.
- *
- * If @vma is NULL, return the first vma in the mm.
- *
- * Returns: The next VMA after @vma.
- */
-static inline struct vm_area_struct *__vma_next(struct mm_struct *mm,
- struct vm_area_struct *vma)
-{
- if (!vma)
- return mm->mmap;
-
- return vma->vm_next;
-}
-
static unsigned long count_vma_pages_range(struct mm_struct *mm,
unsigned long addr, unsigned long end)
{
@@ -599,8 +545,7 @@ static inline void vma_mas_szero(struct ma_state *mas, unsigned long start,
mas_store_prealloc(mas, NULL);
}

-static int vma_link(struct mm_struct *mm, struct vm_area_struct *vma,
- struct vm_area_struct *prev)
+static int vma_link(struct mm_struct *mm, struct vm_area_struct *vma)
{
MA_STATE(mas, &mm->mm_mt, 0, 0);
struct address_space *mapping = NULL;
@@ -614,7 +559,6 @@ static int vma_link(struct mm_struct *mm, struct vm_area_struct *vma,
}

vma_mas_store(vma, &mas);
- __vma_link_list(mm, vma, prev);
__vma_link_file(vma);

if (mapping)
@@ -625,22 +569,6 @@ static int vma_link(struct mm_struct *mm, struct vm_area_struct *vma,
return 0;
}

-/*
- * Helper for vma_adjust() in the split_vma insert case: insert a vma into the
- * mm's list and the mm tree. It has already been inserted into the interval tree.
- */
-static void __insert_vm_struct(struct mm_struct *mm, struct ma_state *mas,
- struct vm_area_struct *vma, unsigned long location)
-{
- struct vm_area_struct *prev;
-
- mas_set(mas, location);
- prev = mas_prev(mas, 0);
- vma_mas_store(vma, mas);
- __vma_link_list(mm, vma, prev);
- mm->map_count++;
-}
-
/*
* vma_expand - Expand an existing VMA
*
@@ -717,15 +645,8 @@ inline int vma_expand(struct ma_state *mas, struct vm_area_struct *vma,
}

/* Expanding over the next vma */
- if (remove_next) {
- /* Remove from mm linked list - also updates highest_vm_end */
- __vma_unlink_list(mm, next);
-
- if (file)
- __remove_shared_vm_struct(next, file, mapping);
-
- } else if (!next) {
- mm->highest_vm_end = vm_end_gap(vma);
+ if (remove_next && file) {
+ __remove_shared_vm_struct(next, file, mapping);
}

if (anon_vma) {
@@ -782,7 +703,6 @@ int __vma_adjust(struct vm_area_struct *vma, unsigned long start,
int remove_next = 0;
MA_STATE(mas, &mm->mm_mt, 0, 0);
struct vm_area_struct *exporter = NULL, *importer = NULL;
- unsigned long ll_prev = vma->vm_start; /* linked list prev. */

if (next && !insert) {
if (end >= next->vm_end) {
@@ -828,7 +748,7 @@ int __vma_adjust(struct vm_area_struct *vma, unsigned long start,
* next, if the vma overlaps with it.
*/
if (remove_next == 2 && !next->anon_vma)
- exporter = next->vm_next;
+ exporter = find_vma(mm, next->vm_end);

} else if (end > next->vm_start) {
/*
@@ -927,17 +847,14 @@ int __vma_adjust(struct vm_area_struct *vma, unsigned long start,
if (vma->vm_end > end) {
if (!insert || (insert->vm_start != end)) {
vma_mas_szero(&mas, end, vma->vm_end);
+ mas_reset(&mas);
VM_WARN_ON(insert &&
insert->vm_end < vma->vm_end);
- } else if (insert->vm_start == end) {
- ll_prev = vma->vm_end;
}
} else {
vma_changed = true;
}
vma->vm_end = end;
- if (!next)
- mm->highest_vm_end = vm_end_gap(vma);
}

if (vma_changed)
@@ -957,17 +874,17 @@ int __vma_adjust(struct vm_area_struct *vma, unsigned long start,
flush_dcache_mmap_unlock(mapping);
}

- if (remove_next) {
- __vma_unlink_list(mm, next);
- if (file)
- __remove_shared_vm_struct(next, file, mapping);
+ if (remove_next && file) {
+ __remove_shared_vm_struct(next, file, mapping);
} else if (insert) {
/*
* split_vma has split insert from vma, and needs
* us to insert it before dropping the locks
* (it may either follow vma or precede it).
*/
- __insert_vm_struct(mm, &mas, insert, ll_prev);
+ mas_reset(&mas);
+ vma_mas_store(insert, &mas);
+ mm->map_count++;
}

if (anon_vma) {
@@ -1006,8 +923,8 @@ int __vma_adjust(struct vm_area_struct *vma, unsigned long start,
/*
* If "next" was removed and vma->vm_end was
* expanded (up) over it, in turn
- * "next->vm_prev->vm_end" changed and the
- * "vma->vm_next" gap must be updated.
+ * "next->prev->vm_end" changed and the
+ * "vma->next" gap must be updated.
*/
next = next_next;
} else {
@@ -1028,34 +945,15 @@ int __vma_adjust(struct vm_area_struct *vma, unsigned long start,
remove_next = 1;
end = next->vm_end;
goto again;
- } else if (!next) {
- /*
- * If remove_next == 2 we obviously can't
- * reach this path.
- *
- * If remove_next == 3 we can't reach this
- * path because pre-swap() next is always not
- * NULL. pre-swap() "next" is not being
- * removed and its next->vm_end is not altered
- * (and furthermore "end" already matches
- * next->vm_end in remove_next == 3).
- *
- * We reach this only in the remove_next == 1
- * case if the "next" vma that was removed was
- * the highest vma of the mm. However in such
- * case next->vm_end == "end" and the extended
- * "vma" has vma->vm_end == next->vm_end so
- * mm->highest_vm_end doesn't need any update
- * in remove_next == 1 case.
- */
- VM_WARN_ON(mm->highest_vm_end != vm_end_gap(vma));
}
}
- if (insert && file)
+ if (insert && file) {
uprobe_mmap(insert);
+ }

mas_destroy(&mas);
validate_mm(mm);
+
return 0;
}

@@ -1215,10 +1113,10 @@ struct vm_area_struct *vma_merge(struct mm_struct *mm,
if (vm_flags & VM_SPECIAL)
return NULL;

- next = __vma_next(mm, prev);
+ next = find_vma(mm, prev ? prev->vm_end : 0);
area = next;
if (area && area->vm_end == end) /* cases 6, 7, 8 */
- next = next->vm_next;
+ next = find_vma(mm, next->vm_end);

/* verify some invariant that must be enforced by the caller */
VM_WARN_ON(prev && addr <= prev->vm_start);
@@ -1352,18 +1250,24 @@ static struct anon_vma *reusable_anon_vma(struct vm_area_struct *old, struct vm_
*/
struct anon_vma *find_mergeable_anon_vma(struct vm_area_struct *vma)
{
+ MA_STATE(mas, &vma->vm_mm->mm_mt, vma->vm_end, vma->vm_end);
struct anon_vma *anon_vma = NULL;
+ struct vm_area_struct *prev, *next;

/* Try next first. */
- if (vma->vm_next) {
- anon_vma = reusable_anon_vma(vma->vm_next, vma, vma->vm_next);
+ next = mas_walk(&mas);
+ if (next) {
+ anon_vma = reusable_anon_vma(next, vma, next);
if (anon_vma)
return anon_vma;
}

+ prev = mas_prev(&mas, 0);
+ VM_BUG_ON_VMA(prev != vma, vma);
+ prev = mas_prev(&mas, 0);
/* Try prev next. */
- if (vma->vm_prev)
- anon_vma = reusable_anon_vma(vma->vm_prev, vma->vm_prev, vma);
+ if (prev)
+ anon_vma = reusable_anon_vma(prev, prev, vma);

/*
* We might reach here with anon_vma == NULL if we can't find
@@ -2112,8 +2016,8 @@ int expand_upwards(struct vm_area_struct *vma, unsigned long address)
if (gap_addr < address || gap_addr > TASK_SIZE)
gap_addr = TASK_SIZE;

- next = vma->vm_next;
- if (next && next->vm_start < gap_addr && vma_is_accessible(next)) {
+ next = find_vma_intersection(mm, vma->vm_end, gap_addr);
+ if (next && vma_is_accessible(next)) {
if (!(next->vm_flags & VM_GROWSUP))
return -ENOMEM;
/* Check that both stack segments have the same anon_vma? */
@@ -2164,8 +2068,6 @@ int expand_upwards(struct vm_area_struct *vma, unsigned long address)
/* Overwrite old entry in mtree. */
vma_mas_store(vma, &mas);
anon_vma_interval_tree_post_update_vma(vma);
- if (!vma->vm_next)
- mm->highest_vm_end = vm_end_gap(vma);
spin_unlock(&mm->page_table_lock);

perf_event_mmap(vma);
@@ -2184,16 +2086,16 @@ int expand_upwards(struct vm_area_struct *vma, unsigned long address)
int expand_downwards(struct vm_area_struct *vma, unsigned long address)
{
struct mm_struct *mm = vma->vm_mm;
+ MA_STATE(mas, &mm->mm_mt, vma->vm_start, vma->vm_start);
struct vm_area_struct *prev;
int error = 0;
- MA_STATE(mas, &mm->mm_mt, 0, 0);

address &= PAGE_MASK;
if (address < mmap_min_addr)
return -EPERM;

/* Enforce stack_guard_gap */
- prev = vma->vm_prev;
+ prev = mas_prev(&mas, 0);
/* Check that both stack segments have the same anon_vma? */
if (prev && !(prev->vm_flags & VM_GROWSDOWN) &&
vma_is_accessible(prev)) {
@@ -2328,25 +2230,26 @@ find_extend_vma(struct mm_struct *mm, unsigned long addr)
EXPORT_SYMBOL_GPL(find_extend_vma);

/*
- * Ok - we have the memory areas we should free on the vma list,
- * so release them, and do the vma updates.
+ * Ok - we have the memory areas we should free on a maple tree so release them,
+ * and do the vma updates.
*
* Called with the mm semaphore held.
*/
-static void remove_vma_list(struct mm_struct *mm, struct vm_area_struct *vma)
+static inline void remove_mt(struct mm_struct *mm, struct ma_state *mas)
{
unsigned long nr_accounted = 0;
+ struct vm_area_struct *vma;

/* Update high watermark before we lower total_vm */
update_hiwater_vm(mm);
- do {
+ mas_for_each(mas, vma, ULONG_MAX) {
long nrpages = vma_pages(vma);

if (vma->vm_flags & VM_ACCOUNT)
nr_accounted += nrpages;
vm_stat_account(mm, vma->vm_flags, -nrpages);
- vma = remove_vma(vma);
- } while (vma);
+ remove_vma(vma);
+ }
vm_unacct_memory(nr_accounted);
validate_mm(mm);
}
@@ -2356,18 +2259,18 @@ static void remove_vma_list(struct mm_struct *mm, struct vm_area_struct *vma)
*
* Called with the mm semaphore held.
*/
-static void unmap_region(struct mm_struct *mm,
+static void unmap_region(struct mm_struct *mm, struct maple_tree *mt,
struct vm_area_struct *vma, struct vm_area_struct *prev,
+ struct vm_area_struct *next,
unsigned long start, unsigned long end)
{
- struct vm_area_struct *next = __vma_next(mm, prev);
struct mmu_gather tlb;

lru_add_drain();
tlb_gather_mmu(&tlb, mm);
update_hiwater_rss(mm);
- unmap_vmas(&tlb, vma, start, end);
- free_pgtables(&tlb, vma, prev ? prev->vm_end : FIRST_USER_ADDRESS,
+ unmap_vmas(&tlb, mt, vma, start, end);
+ free_pgtables(&tlb, mt, vma, prev ? prev->vm_end : FIRST_USER_ADDRESS,
next ? next->vm_start : USER_PGTABLES_CEILING);
tlb_finish_mmu(&tlb);
}
@@ -2451,24 +2354,13 @@ int split_vma(struct mm_struct *mm, struct vm_area_struct *vma,
return __split_vma(mm, vma, addr, new_below);
}

-static inline int
-unlock_range(struct vm_area_struct *start, struct vm_area_struct **tail,
- unsigned long limit)
+static inline void munmap_sidetree(struct vm_area_struct *vma,
+ struct ma_state *mas_detach)
{
- struct mm_struct *mm = start->vm_mm;
- struct vm_area_struct *tmp = start;
- int count = 0;
-
- while (tmp && tmp->vm_start < limit) {
- *tail = tmp;
- count++;
- if (tmp->vm_flags & VM_LOCKED)
- mm->locked_vm -= vma_pages(tmp);
-
- tmp = tmp->vm_next;
- }
-
- return count;
+ mas_set_range(mas_detach, vma->vm_start, vma->vm_end - 1);
+ mas_store(mas_detach, vma);
+ if (vma->vm_flags & VM_LOCKED)
+ vma->vm_mm->locked_vm -= vma_pages(vma);
}

/*
@@ -2488,13 +2380,20 @@ do_mas_align_munmap(struct ma_state *mas, struct vm_area_struct *vma,
struct mm_struct *mm, unsigned long start,
unsigned long end, struct list_head *uf, bool downgrade)
{
- struct vm_area_struct *prev, *last;
+ struct vm_area_struct *prev, *next = NULL;
+ struct maple_tree mt_detach;
+ int count = 0;
int error = -ENOMEM;
- /* we have start < vma->vm_end */
+ MA_STATE(mas_detach, &mt_detach, start, end - 1);
+ mt_init_flags(&mt_detach, MM_MT_FLAGS);
+ mt_set_external_lock(&mt_detach, &mm->mmap_lock);

if (mas_preallocate(mas, vma, GFP_KERNEL))
return -ENOMEM;

+ if (mas_preallocate(&mas_detach, vma, GFP_KERNEL))
+ return -ENOMEM;
+
mas->last = end - 1;
/*
* If we need to split any vma, do it now to save pain later.
@@ -2503,6 +2402,8 @@ do_mas_align_munmap(struct ma_state *mas, struct vm_area_struct *vma,
* unmapped vm_area_struct will remain in use: so lower split_vma
* places tmp vma above, and higher split_vma places tmp vma below.
*/
+
+ /* Does it split the first one? */
if (start > vma->vm_start) {

/*
@@ -2513,35 +2414,56 @@ do_mas_align_munmap(struct ma_state *mas, struct vm_area_struct *vma,
if (end < vma->vm_end && mm->map_count >= sysctl_max_map_count)
goto map_count_exceeded;

+ /*
+ * mas_pause() is not needed since mas->index needs to be set
+ * differently than vma->vm_end anyways.
+ */
error = __split_vma(mm, vma, start, 0);
if (error)
goto split_failed;

- prev = vma;
- vma = __vma_next(mm, prev);
- mas->index = start;
- mas_reset(mas);
- } else {
- prev = vma->vm_prev;
+ mas_set(mas, start);
+ vma = mas_walk(mas);
}

- if (vma->vm_end >= end)
- last = vma;
- else
- last = find_vma_intersection(mm, end - 1, end);
-
- /* Does it split the last one? */
- if (last && end < last->vm_end) {
- error = __split_vma(mm, last, end, 1);
+ prev = mas_prev(mas, 0);
+ if (unlikely((!prev)))
+ mas_set(mas, start);

- if (error)
- goto split_failed;
+ /*
+ * Detach a range of VMAs from the mm. Using next as a temp variable as
+ * it is always overwritten.
+ */
+ mas_for_each(mas, next, end - 1) {
+ /* Does it split the end? */
+ if (next->vm_end > end) {
+ struct vm_area_struct *split;

- if (vma == last)
- vma = __vma_next(mm, prev);
- mas_reset(mas);
+ error = __split_vma(mm, next, end, 1);
+ if (error)
+ goto split_failed;
+
+ mas_set(mas, end);
+ split = mas_prev(mas, 0);
+ munmap_sidetree(split, &mas_detach);
+ count++;
+ if (vma == next)
+ vma = split;
+ break;
+ }
+ count++;
+ munmap_sidetree(next, &mas_detach);
+#ifdef CONFIG_DEBUG_VM_MAPLE_TREE
+ BUG_ON(next->vm_start < start);
+ BUG_ON(next->vm_start > end);
+#endif
}

+ mas_destroy(&mas_detach);
+
+ if (!next)
+ next = mas_next(mas, ULONG_MAX);
+
if (unlikely(uf)) {
/*
* If userfaultfd_unmap_prep returns an error the vmas
@@ -2558,35 +2480,36 @@ do_mas_align_munmap(struct ma_state *mas, struct vm_area_struct *vma,
goto userfaultfd_error;
}

- /*
- * unlock any mlock()ed ranges before detaching vmas, count the number
- * of VMAs to be dropped, and return the tail entry of the affected
- * area.
- */
- mm->map_count -= unlock_range(vma, &last, end);
- /* Drop removed area from the tree */
+ /* Point of no return */
+ mas_set_range(mas, start, end - 1);
+#if defined(CONFIG_DEBUG_VM_MAPLE_TREE)
+ /* Make sure no VMAs are about to be lost. */
+ {
+ MA_STATE(test, &mt_detach, start, end - 1);
+ struct vm_area_struct *vma_mas, *vma_test;
+ int test_count = 0;
+
+ rcu_read_lock();
+ vma_test = mas_find(&test, end - 1);
+ mas_for_each(mas, vma_mas, end - 1) {
+ BUG_ON(vma_mas != vma_test);
+ test_count++;
+ vma_test = mas_next(&test, end - 1);
+ }
+ rcu_read_unlock();
+ BUG_ON(count != test_count);
+ mas_set_range(mas, start, end - 1);
+ }
+#endif
mas_store_prealloc(mas, NULL);
-
- /* Detach vmas from the MM linked list */
- vma->vm_prev = NULL;
- if (prev)
- prev->vm_next = last->vm_next;
- else
- mm->mmap = last->vm_next;
-
- if (last->vm_next) {
- last->vm_next->vm_prev = prev;
- last->vm_next = NULL;
- } else
- mm->highest_vm_end = prev ? vm_end_gap(prev) : 0;
-
+ mm->map_count -= count;
/*
* Do not downgrade mmap_lock if we are next to VM_GROWSDOWN or
* VM_GROWSUP VMA. Such VMAs can change their size under
* down_read(mmap_lock) and collide with the VMA we are about to unmap.
*/
if (downgrade) {
- if (last && (last->vm_flags & VM_GROWSDOWN))
+ if (next && (next->vm_flags & VM_GROWSDOWN))
downgrade = false;
else if (prev && (prev->vm_flags & VM_GROWSUP))
downgrade = false;
@@ -2594,10 +2517,12 @@ do_mas_align_munmap(struct ma_state *mas, struct vm_area_struct *vma,
mmap_write_downgrade(mm);
}

- unmap_region(mm, vma, prev, start, end);
-
- /* Fix up all other VM information */
- remove_vma_list(mm, vma);
+ unmap_region(mm, &mt_detach, vma, prev, next, start, end);
+ /* Statistics and freeing VMAs */
+ mas_set(&mas_detach, start);
+ remove_mt(mm, &mas_detach);
+ validate_mm(mm);
+ __mt_destroy(&mt_detach);


validate_mm(mm);
@@ -2838,7 +2763,6 @@ unsigned long mmap_region(struct file *file, unsigned long addr,
i_mmap_lock_write(vma->vm_file->f_mapping);

vma_mas_store(vma, &mas);
- __vma_link_list(mm, vma, prev);
mm->map_count++;
if (vma->vm_file) {
if (vma->vm_flags & VM_SHARED)
@@ -2890,7 +2814,7 @@ unsigned long mmap_region(struct file *file, unsigned long addr,
vma->vm_file = NULL;

/* Undo any partial mapping done by a device driver. */
- unmap_region(mm, vma, prev, vma->vm_start, vma->vm_end);
+ unmap_region(mm, mas.tree, vma, prev, next, vma->vm_start, vma->vm_end);
charged = 0;
if (vm_flags & VM_SHARED)
mapping_unmap_writable(file->f_mapping);
@@ -2979,11 +2903,12 @@ SYSCALL_DEFINE5(remap_file_pages, unsigned long, start, unsigned long, size,
goto out;

if (start + size > vma->vm_end) {
- struct vm_area_struct *next;
+ VMA_ITERATOR(vmi, mm, vma->vm_end);
+ struct vm_area_struct *next, *prev = vma;

- for (next = vma->vm_next; next; next = next->vm_next) {
+ for_each_vma_range(vmi, next, start + size) {
/* hole between vmas ? */
- if (next->vm_start != next->vm_prev->vm_end)
+ if (next->vm_start != prev->vm_end)
goto out;

if (next->vm_file != vma->vm_file)
@@ -2992,8 +2917,7 @@ SYSCALL_DEFINE5(remap_file_pages, unsigned long, start, unsigned long, size,
if (next->vm_flags != vma->vm_flags)
goto out;

- if (start + size <= next->vm_end)
- break;
+ prev = next;
}

if (!next)
@@ -3039,7 +2963,7 @@ static int do_brk_munmap(struct ma_state *mas, struct vm_area_struct *vma,
struct list_head *uf)
{
struct mm_struct *mm = vma->vm_mm;
- struct vm_area_struct unmap;
+ struct vm_area_struct unmap, *next;
unsigned long unmap_pages;
int ret;

@@ -3056,6 +2980,7 @@ static int do_brk_munmap(struct ma_state *mas, struct vm_area_struct *vma,
ret = userfaultfd_unmap_prep(mm, newbrk, oldbrk, uf);
if (ret)
return ret;
+
ret = 1;

/* Change the oldbrk of vma to the newbrk of the munmap area */
@@ -3077,6 +3002,7 @@ static int do_brk_munmap(struct ma_state *mas, struct vm_area_struct *vma,

vma_mas_remove(&unmap, mas);

+ vma->vm_end = newbrk;
if (vma->anon_vma) {
anon_vma_interval_tree_post_update_vma(vma);
anon_vma_unlock_write(vma->anon_vma);
@@ -3086,8 +3012,9 @@ static int do_brk_munmap(struct ma_state *mas, struct vm_area_struct *vma,
if (vma->vm_flags & VM_LOCKED)
mm->locked_vm -= unmap_pages;

+ next = mas_next(mas, ULONG_MAX);
mmap_write_downgrade(mm);
- unmap_region(mm, &unmap, vma, newbrk, oldbrk);
+ unmap_region(mm, mas->tree, &unmap, vma, next, newbrk, oldbrk);
/* Statistics */
vm_stat_account(mm, vma->vm_flags, -unmap_pages);
if (vma->vm_flags & VM_ACCOUNT)
@@ -3111,11 +3038,9 @@ static int do_brk_munmap(struct ma_state *mas, struct vm_area_struct *vma,
* do some brk-specific accounting here.
*/
static int do_brk_flags(struct ma_state *mas, struct vm_area_struct *vma,
- unsigned long addr, unsigned long len,
- unsigned long flags)
+ unsigned long addr, unsigned long len, unsigned long flags)
{
struct mm_struct *mm = current->mm;
- struct vm_area_struct *prev = NULL;
validate_mm_mt(mm);


@@ -3159,7 +3084,6 @@ static int do_brk_flags(struct ma_state *mas, struct vm_area_struct *vma,
khugepaged_enter_vma_merge(vma, flags);
goto out;
}
- prev = vma;

/* create a vma struct for an anonymous mapping */
vma = vm_area_alloc(mm);
@@ -3177,12 +3101,6 @@ static int do_brk_flags(struct ma_state *mas, struct vm_area_struct *vma,
goto mas_store_fail;

mm->map_count++;
-
- if (!prev)
- prev = mas_prev(mas, 0);
-
- __vma_link_list(mm, vma, prev);
- mm->map_count++;
out:
perf_event_mmap(vma);
mm->total_vm += len >> PAGE_SHIFT;
@@ -3190,7 +3108,7 @@ static int do_brk_flags(struct ma_state *mas, struct vm_area_struct *vma,
if (flags & VM_LOCKED)
mm->locked_vm += (len >> PAGE_SHIFT);
vma->vm_flags |= VM_SOFTDIRTY;
- validate_mm_mt(mm);
+ validate_mm(mm);
return 0;

mas_store_fail:
@@ -3264,6 +3182,8 @@ void exit_mmap(struct mm_struct *mm)
struct mmu_gather tlb;
struct vm_area_struct *vma;
unsigned long nr_accounted = 0;
+ MA_STATE(mas, &mm->mm_mt, 0, 0);
+ int count = 0;

/* mm's last user has gone, and its about to be pulled down */
mmu_notifier_release(mm);
@@ -3287,7 +3207,7 @@ void exit_mmap(struct mm_struct *mm)
}

arch_exit_mmap(mm);
- vma = mm->mmap;
+ vma = mas_find(&mas, ULONG_MAX);
if (!vma) {
/* Can happen if dup_mmap() received an OOM */
mmap_write_unlock(mm);
@@ -3299,17 +3219,25 @@ void exit_mmap(struct mm_struct *mm)
tlb_gather_mmu_fullmm(&tlb, mm);
/* update_hiwater_rss(mm) here? but nobody should be looking */
/* Use -1 here to ensure all VMAs in the mm are unmapped */
- unmap_vmas(&tlb, vma, 0, -1);
- free_pgtables(&tlb, vma, FIRST_USER_ADDRESS, USER_PGTABLES_CEILING);
+ unmap_vmas(&tlb, &mm->mm_mt, vma, 0, ULONG_MAX);
+ free_pgtables(&tlb, &mm->mm_mt, vma, FIRST_USER_ADDRESS, USER_PGTABLES_CEILING);
tlb_finish_mmu(&tlb);

- /* Walk the list again, actually closing and freeing it. */
- while (vma) {
+ /*
+ * Walk the list again, actually closing and freeing it, with preemption
+ * enabled, without holding any MM locks besides the unreachable
+ * mmap_write_lock.
+ */
+ do {
if (vma->vm_flags & VM_ACCOUNT)
nr_accounted += vma_pages(vma);
- vma = remove_vma(vma);
+ remove_vma(vma);
+ count++;
cond_resched();
- }
+ } while ((vma = mas_find(&mas, ULONG_MAX)) != NULL);
+
+ BUG_ON(count != mm->map_count);
+

trace_exit_mmap(mm);
__mt_destroy(&mm->mm_mt);
@@ -3349,7 +3277,7 @@ int insert_vm_struct(struct mm_struct *mm, struct vm_area_struct *vma)
vma->vm_pgoff = vma->vm_start >> PAGE_SHIFT;
}

- if (vma_link(mm, vma, prev))
+ if (vma_link(mm, vma))
return -ENOMEM;

return 0;
@@ -3379,7 +3307,8 @@ struct vm_area_struct *copy_vma(struct vm_area_struct **vmap,
faulted_in_anon_vma = false;
}

- if (range_has_overlap(mm, addr, addr + len, &prev))
+ new_vma = find_vma_prev(mm, addr, &prev);
+ if (new_vma->vm_start < addr + len)
return NULL; /* should never get here */

new_vma = vma_merge(mm, prev, addr, addr + len, vma->vm_flags,
@@ -3422,7 +3351,7 @@ struct vm_area_struct *copy_vma(struct vm_area_struct **vmap,
get_file(new_vma->vm_file);
if (new_vma->vm_ops && new_vma->vm_ops->open)
new_vma->vm_ops->open(new_vma);
- if (vma_link(mm, new_vma, prev))
+ if (vma_link(mm, new_vma))
goto out_vma_link;
*need_rmap_locks = false;
}
@@ -3727,12 +3656,13 @@ int mm_take_all_locks(struct mm_struct *mm)
{
struct vm_area_struct *vma;
struct anon_vma_chain *avc;
+ MA_STATE(mas, &mm->mm_mt, 0, 0);

mmap_assert_write_locked(mm);

mutex_lock(&mm_all_locks_mutex);

- for (vma = mm->mmap; vma; vma = vma->vm_next) {
+ mas_for_each(&mas, vma, ULONG_MAX) {
if (signal_pending(current))
goto out_unlock;
if (vma->vm_file && vma->vm_file->f_mapping &&
@@ -3740,7 +3670,8 @@ int mm_take_all_locks(struct mm_struct *mm)
vm_lock_mapping(mm, vma->vm_file->f_mapping);
}

- for (vma = mm->mmap; vma; vma = vma->vm_next) {
+ mas_set(&mas, 0);
+ mas_for_each(&mas, vma, ULONG_MAX) {
if (signal_pending(current))
goto out_unlock;
if (vma->vm_file && vma->vm_file->f_mapping &&
@@ -3748,7 +3679,8 @@ int mm_take_all_locks(struct mm_struct *mm)
vm_lock_mapping(mm, vma->vm_file->f_mapping);
}

- for (vma = mm->mmap; vma; vma = vma->vm_next) {
+ mas_set(&mas, 0);
+ mas_for_each(&mas, vma, ULONG_MAX) {
if (signal_pending(current))
goto out_unlock;
if (vma->anon_vma)
@@ -3807,11 +3739,12 @@ void mm_drop_all_locks(struct mm_struct *mm)
{
struct vm_area_struct *vma;
struct anon_vma_chain *avc;
+ MA_STATE(mas, &mm->mm_mt, 0, 0);

mmap_assert_write_locked(mm);
BUG_ON(!mutex_is_locked(&mm_all_locks_mutex));

- for (vma = mm->mmap; vma; vma = vma->vm_next) {
+ mas_for_each(&mas, vma, ULONG_MAX) {
if (vma->anon_vma)
list_for_each_entry(avc, &vma->anon_vma_chain, same_vma)
vm_unlock_anon_vma(avc->anon_vma);
diff --git a/mm/nommu.c b/mm/nommu.c
index d94f6adf9c31..e32561f9f55f 100644
--- a/mm/nommu.c
+++ b/mm/nommu.c
@@ -553,7 +553,6 @@ static void put_nommu_region(struct vm_region *region)
static void add_vma_to_mm(struct mm_struct *mm, struct vm_area_struct *vma)
{
struct address_space *mapping;
- struct vm_area_struct *prev;
MA_STATE(mas, &mm->mm_mt, vma->vm_start, vma->vm_end);

BUG_ON(!vma->vm_region);
@@ -572,11 +571,8 @@ static void add_vma_to_mm(struct mm_struct *mm, struct vm_area_struct *vma)
i_mmap_unlock_write(mapping);
}

- prev = mas_prev(&mas, 0);
- mas_reset(&mas);
/* add the VMA to the tree */
vma_mas_store(vma, &mas);
- __vma_link_list(mm, vma, prev);
}

/*
@@ -601,7 +597,6 @@ static void delete_vma_from_mm(struct vm_area_struct *vma)

/* remove from the MM's tree and list */
vma_mas_remove(vma, &mas);
- __vma_unlink_list(vma->vm_mm, vma);
}

/*
diff --git a/mm/util.c b/mm/util.c
index 3e97807c353b..136e1775d54c 100644
--- a/mm/util.c
+++ b/mm/util.c
@@ -271,46 +271,6 @@ void *memdup_user_nul(const void __user *src, size_t len)
}
EXPORT_SYMBOL(memdup_user_nul);

-void __vma_link_list(struct mm_struct *mm, struct vm_area_struct *vma,
- struct vm_area_struct *prev)
-{
- struct vm_area_struct *next;
-
- vma->vm_prev = prev;
- if (prev) {
- next = prev->vm_next;
- prev->vm_next = vma;
- } else {
- next = mm->mmap;
- mm->mmap = vma;
- }
- vma->vm_next = next;
- if (next)
- next->vm_prev = vma;
- else
- mm->highest_vm_end = vm_end_gap(vma);
-}
-
-void __vma_unlink_list(struct mm_struct *mm, struct vm_area_struct *vma)
-{
- struct vm_area_struct *prev, *next;
-
- next = vma->vm_next;
- prev = vma->vm_prev;
- if (prev)
- prev->vm_next = next;
- else
- mm->mmap = next;
- if (next) {
- next->vm_prev = prev;
- } else {
- if (prev)
- mm->highest_vm_end = vm_end_gap(prev);
- else
- mm->highest_vm_end = 0;
- }
-}
-
/* Check if the vma is being used as a stack by this task */
int vma_is_stack_for_current(struct vm_area_struct *vma)
{
--
2.35.1