[PATCH 25/64] mm: use mm locking wrappers

From: Davidlohr Bueso
Date: Sun Feb 04 2018 - 20:38:31 EST

From: Davidlohr Bueso <dave@xxxxxxxxxxxx>

Most of the mmap_sem users are already aware of mmrange,
making the conversion straightforward. Those who don't,
simply use the mmap_sem within the same function context.
No change in semantics.

Signed-off-by: Davidlohr Bueso <dbueso@xxxxxxx>
---
mm/filemap.c | 4 ++--
mm/frame_vector.c | 4 ++--
mm/gup.c | 16 ++++++++--------
mm/khugepaged.c | 35 +++++++++++++++++++----------------
mm/memcontrol.c | 10 +++++-----
mm/memory.c | 9 +++++----
mm/mempolicy.c | 21 +++++++++++----------
mm/migrate.c | 10 ++++++----
mm/mincore.c | 4 ++--
mm/mmap.c | 30 +++++++++++++++++-------------
mm/mprotect.c | 14 ++++++++------
mm/mremap.c | 4 ++--
mm/msync.c | 9 +++++----
mm/nommu.c | 23 +++++++++++++----------
mm/oom_kill.c | 8 ++++----
mm/pagewalk.c | 4 ++--
mm/process_vm_access.c | 4 ++--
mm/shmem.c | 2 +-
mm/swapfile.c | 7 ++++---
mm/userfaultfd.c | 24 ++++++++++++++----------
mm/util.c | 9 +++++----
21 files changed, 137 insertions(+), 114 deletions(-)

diff --git a/mm/filemap.c b/mm/filemap.c
index 6124ede79a4d..b56f93e14992 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -1303,7 +1303,7 @@ int __lock_page_or_retry(struct page *page, struct mm_struct *mm,
if (flags & FAULT_FLAG_RETRY_NOWAIT)
return 0;

- up_read(&mm->mmap_sem);
+ mm_read_unlock(mm, mmrange);
if (flags & FAULT_FLAG_KILLABLE)
wait_on_page_locked_killable(page);
else
@@ -1315,7 +1315,7 @@ int __lock_page_or_retry(struct page *page, struct mm_struct *mm,

ret = __lock_page_killable(page);
if (ret) {
- up_read(&mm->mmap_sem);
+ mm_read_unlock(mm, mmrange);
return 0;
}
} else
diff --git a/mm/frame_vector.c b/mm/frame_vector.c
index d3dccd80c6ee..2074f6c4d6e9 100644
--- a/mm/frame_vector.c
+++ b/mm/frame_vector.c
@@ -47,7 +47,7 @@ int get_vaddr_frames(unsigned long start, unsigned int nr_frames,
if (WARN_ON_ONCE(nr_frames > vec->nr_allocated))
nr_frames = vec->nr_allocated;

- down_read(&mm->mmap_sem);
+ mm_read_lock(mm, &mmrange);
locked = 1;
vma = find_vma_intersection(mm, start, start + 1);
if (!vma) {
@@ -102,7 +102,7 @@ int get_vaddr_frames(unsigned long start, unsigned int nr_frames,
} while (vma && vma->vm_flags & (VM_IO | VM_PFNMAP));
out:
if (locked)
- up_read(&mm->mmap_sem);
+ mm_read_unlock(mm, &mmrange);
if (!ret)
ret = -EFAULT;
if (ret > 0)
diff --git a/mm/gup.c b/mm/gup.c
index 3d1b6dd11616..08d7c17e9f06 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -827,7 +827,7 @@ int fixup_user_fault(struct task_struct *tsk, struct mm_struct *mm,
}

if (ret & VM_FAULT_RETRY) {
- down_read(&mm->mmap_sem);
+ mm_read_lock(mm, mmrange);
if (!(fault_flags & FAULT_FLAG_TRIED)) {
*unlocked = true;
fault_flags &= ~FAULT_FLAG_ALLOW_RETRY;
@@ -911,7 +911,7 @@ static __always_inline long __get_user_pages_locked(struct task_struct *tsk,
*/
*locked = 1;
lock_dropped = true;
- down_read(&mm->mmap_sem);
+ mm_read_lock(mm, mmrange);
ret = __get_user_pages(tsk, mm, start, 1, flags | FOLL_TRIED,
pages, NULL, NULL, mmrange);
if (ret != 1) {
@@ -932,7 +932,7 @@ static __always_inline long __get_user_pages_locked(struct task_struct *tsk,
* We must let the caller know we temporarily dropped the lock
* and so the critical section protected by it was lost.
*/
- up_read(&mm->mmap_sem);
+ mm_read_unlock(mm, mmrange);
*locked = 0;
}
return pages_done;
@@ -992,11 +992,11 @@ long get_user_pages_unlocked(unsigned long start, unsigned long nr_pages,
long ret;
DEFINE_RANGE_LOCK_FULL(mmrange);

- down_read(&mm->mmap_sem);
+ mm_read_lock(mm, &mmrange);
ret = __get_user_pages_locked(current, mm, start, nr_pages, pages, NULL,
&locked, gup_flags | FOLL_TOUCH, &mmrange);
if (locked)
- up_read(&mm->mmap_sem);
+ mm_read_unlock(mm, &mmrange);
return ret;
}
EXPORT_SYMBOL(get_user_pages_unlocked);
@@ -1184,7 +1184,7 @@ long populate_vma_page_range(struct vm_area_struct *vma,
VM_BUG_ON(end & ~PAGE_MASK);
VM_BUG_ON_VMA(start < vma->vm_start, vma);
VM_BUG_ON_VMA(end > vma->vm_end, vma);
- VM_BUG_ON_MM(!rwsem_is_locked(&mm->mmap_sem), mm);
+ VM_BUG_ON_MM(!mm_is_locked(mm, mmrange), mm);

gup_flags = FOLL_TOUCH | FOLL_POPULATE | FOLL_MLOCK;
if (vma->vm_flags & VM_LOCKONFAULT)
@@ -1239,7 +1239,7 @@ int __mm_populate(unsigned long start, unsigned long len, int ignore_errors)
*/
if (!locked) {
locked = 1;
- down_read(&mm->mmap_sem);
+ mm_read_lock(mm, &mmrange);
vma = find_vma(mm, nstart);
} else if (nstart >= vma->vm_end)
vma = vma->vm_next;
@@ -1271,7 +1271,7 @@ int __mm_populate(unsigned long start, unsigned long len, int ignore_errors)
ret = 0;
}
if (locked)
- up_read(&mm->mmap_sem);
+ mm_read_unlock(mm, &mmrange);
return ret; /* 0 or negative error code */
}

diff --git a/mm/khugepaged.c b/mm/khugepaged.c
index 0b91ce730160..9076d26d162a 100644
--- a/mm/khugepaged.c
+++ b/mm/khugepaged.c
@@ -469,6 +469,8 @@ void __khugepaged_exit(struct mm_struct *mm)
free_mm_slot(mm_slot);
mmdrop(mm);
} else if (mm_slot) {
+ DEFINE_RANGE_LOCK_FULL(mmrange);
+
/*
* This is required to serialize against
* khugepaged_test_exit() (which is guaranteed to run
@@ -477,8 +479,8 @@ void __khugepaged_exit(struct mm_struct *mm)
* khugepaged has finished working on the pagetables
* under the mmap_sem.
*/
- down_write(&mm->mmap_sem);
- up_write(&mm->mmap_sem);
+ mm_write_lock(mm, &mmrange);
+ mm_write_unlock(mm, &mmrange);
}
}

@@ -902,7 +904,7 @@ static bool __collapse_huge_page_swapin(struct mm_struct *mm,

/* do_swap_page returns VM_FAULT_RETRY with released mmap_sem */
if (ret & VM_FAULT_RETRY) {
- down_read(&mm->mmap_sem);
+ mm_read_lock(mm, mmrange);
if (hugepage_vma_revalidate(mm, address, &vmf.vma)) {
/* vma is no longer available, don't continue to swapin */
trace_mm_collapse_huge_page_swapin(mm, swapped_in, referenced, 0);
@@ -956,7 +958,7 @@ static void collapse_huge_page(struct mm_struct *mm,
* sync compaction, and we do not need to hold the mmap_sem during
* that. We will recheck the vma after taking it again in write mode.
*/
- up_read(&mm->mmap_sem);
+ mm_read_unlock(mm, mmrange);
new_page = khugepaged_alloc_page(hpage, gfp, node);
if (!new_page) {
result = SCAN_ALLOC_HUGE_PAGE_FAIL;
@@ -968,11 +970,11 @@ static void collapse_huge_page(struct mm_struct *mm,
goto out_nolock;
}

- down_read(&mm->mmap_sem);
+ mm_read_lock(mm, mmrange);
result = hugepage_vma_revalidate(mm, address, &vma);
if (result) {
mem_cgroup_cancel_charge(new_page, memcg, true);
- up_read(&mm->mmap_sem);
+ mm_read_unlock(mm, mmrange);
goto out_nolock;
}

@@ -980,7 +982,7 @@ static void collapse_huge_page(struct mm_struct *mm,
if (!pmd) {
result = SCAN_PMD_NULL;
mem_cgroup_cancel_charge(new_page, memcg, true);
- up_read(&mm->mmap_sem);
+ mm_read_unlock(mm, mmrange);
goto out_nolock;
}

@@ -991,17 +993,17 @@ static void collapse_huge_page(struct mm_struct *mm,
*/
if (!__collapse_huge_page_swapin(mm, vma, address, pmd, referenced, mmrange)) {
mem_cgroup_cancel_charge(new_page, memcg, true);
- up_read(&mm->mmap_sem);
+ mm_read_unlock(mm, mmrange);
goto out_nolock;
}

- up_read(&mm->mmap_sem);
+ mm_read_unlock(mm, mmrange);
/*
* Prevent all access to pagetables with the exception of
* gup_fast later handled by the ptep_clear_flush and the VM
* handled by the anon_vma lock + PG_lock.
*/
- down_write(&mm->mmap_sem);
+ mm_write_lock(mm, mmrange);
result = hugepage_vma_revalidate(mm, address, &vma);
if (result)
goto out;
@@ -1084,7 +1086,7 @@ static void collapse_huge_page(struct mm_struct *mm,
khugepaged_pages_collapsed++;
result = SCAN_SUCCEED;
out_up_write:
- up_write(&mm->mmap_sem);
+ mm_write_unlock(mm, mmrange);
out_nolock:
trace_mm_collapse_huge_page(mm, isolated, result);
return;
@@ -1249,6 +1251,7 @@ static void retract_page_tables(struct address_space *mapping, pgoff_t pgoff)
struct vm_area_struct *vma;
unsigned long addr;
pmd_t *pmd, _pmd;
+ DEFINE_RANGE_LOCK_FULL(mmrange);

i_mmap_lock_write(mapping);
vma_interval_tree_foreach(vma, &mapping->i_mmap, pgoff, pgoff) {
@@ -1269,12 +1272,12 @@ static void retract_page_tables(struct address_space *mapping, pgoff_t pgoff)
* re-fault. Not ideal, but it's more important to not disturb
* the system too much.
*/
- if (down_write_trylock(&vma->vm_mm->mmap_sem)) {
+ if (mm_write_trylock(vma->vm_mm, &mmrange)) {
spinlock_t *ptl = pmd_lock(vma->vm_mm, pmd);
/* assume page table is clear */
_pmd = pmdp_collapse_flush(vma, addr, pmd);
spin_unlock(ptl);
- up_write(&vma->vm_mm->mmap_sem);
+ mm_write_unlock(vma->vm_mm, &mmrange);
mm_dec_nr_ptes(vma->vm_mm);
pte_free(vma->vm_mm, pmd_pgtable(_pmd));
}
@@ -1684,7 +1687,7 @@ static unsigned int khugepaged_scan_mm_slot(unsigned int pages,
* the next mm on the list.
*/
vma = NULL;
- if (unlikely(!down_read_trylock(&mm->mmap_sem)))
+ if (unlikely(!mm_read_trylock(mm, &mmrange)))
goto breakouterloop_mmap_sem;
if (likely(!khugepaged_test_exit(mm)))
vma = find_vma(mm, khugepaged_scan.address);
@@ -1729,7 +1732,7 @@ static unsigned int khugepaged_scan_mm_slot(unsigned int pages,
if (!shmem_huge_enabled(vma))
goto skip;
file = get_file(vma->vm_file);
- up_read(&mm->mmap_sem);
+ mm_read_unlock(mm, &mmrange);
ret = 1;
khugepaged_scan_shmem(mm, file->f_mapping,
pgoff, hpage);
@@ -1750,7 +1753,7 @@ static unsigned int khugepaged_scan_mm_slot(unsigned int pages,
}
}
breakouterloop:
- up_read(&mm->mmap_sem); /* exit_mmap will destroy ptes after this */
+ mm_read_unlock(mm, &mmrange); /* exit_mmap will destroy ptes after this */
breakouterloop_mmap_sem:

spin_lock(&khugepaged_mm_lock);
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index a7ac5a14b22e..699d35ffee1a 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -4916,16 +4916,16 @@ static int mem_cgroup_count_precharge_pte_range(pmd_t *pmd,
static unsigned long mem_cgroup_count_precharge(struct mm_struct *mm)
{
unsigned long precharge;
- DEFINE_RANGE_LOCK_FULL(mmrange);

struct mm_walk mem_cgroup_count_precharge_walk = {
.pmd_entry = mem_cgroup_count_precharge_pte_range,
.mm = mm,
};
- down_read(&mm->mmap_sem);
+ DEFINE_RANGE_LOCK_FULL(mmrange);
+ mm_read_lock(mm, &mmrange);
walk_page_range(0, mm->highest_vm_end,
&mem_cgroup_count_precharge_walk, &mmrange);
- up_read(&mm->mmap_sem);
+ mm_read_unlock(mm, &mmrange);

precharge = mc.precharge;
mc.precharge = 0;
@@ -5211,7 +5211,7 @@ static void mem_cgroup_move_charge(void)
atomic_inc(&mc.from->moving_account);
synchronize_rcu();
retry:
- if (unlikely(!down_read_trylock(&mc.mm->mmap_sem))) {
+ if (unlikely(!mm_read_trylock(mc.mm, &mmrange))) {
/*
* Someone who are holding the mmap_sem might be waiting in
* waitq. So we cancel all extra charges, wake up all waiters,
@@ -5230,7 +5230,7 @@ static void mem_cgroup_move_charge(void)
walk_page_range(0, mc.mm->highest_vm_end, &mem_cgroup_move_charge_walk,
&mmrange);

- up_read(&mc.mm->mmap_sem);
+ mm_read_unlock(mc.mm, &mmrange);
atomic_dec(&mc.from->moving_account);
}

diff --git a/mm/memory.c b/mm/memory.c
index 598a8c69e3d3..e3bf2879f7c3 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -4425,7 +4425,7 @@ int __access_remote_vm(struct task_struct *tsk, struct mm_struct *mm,
int write = gup_flags & FOLL_WRITE;
DEFINE_RANGE_LOCK_FULL(mmrange);

- down_read(&mm->mmap_sem);
+ mm_read_lock(mm, &mmrange);
/* ignore errors, just check how much was successfully transferred */
while (len) {
int bytes, ret, offset;
@@ -4474,7 +4474,7 @@ int __access_remote_vm(struct task_struct *tsk, struct mm_struct *mm,
buf += bytes;
addr += bytes;
}
- up_read(&mm->mmap_sem);
+ mm_read_unlock(mm, &mmrange);

return buf - old_buf;
}
@@ -4525,11 +4525,12 @@ void print_vma_addr(char *prefix, unsigned long ip)
{
struct mm_struct *mm = current->mm;
struct vm_area_struct *vma;
+ DEFINE_RANGE_LOCK_FULL(mmrange);

/*
* we might be running from an atomic context so we cannot sleep
*/
- if (!down_read_trylock(&mm->mmap_sem))
+ if (!mm_read_trylock(mm, &mmrange))
return;

vma = find_vma(mm, ip);
@@ -4548,7 +4549,7 @@ void print_vma_addr(char *prefix, unsigned long ip)
free_page((unsigned long)buf);
}
}
- up_read(&mm->mmap_sem);
+ mm_read_unlock(mm, &mmrange);
}

#if defined(CONFIG_PROVE_LOCKING) || defined(CONFIG_DEBUG_ATOMIC_SLEEP)
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 001dc176abc1..93b69c603e8d 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -378,11 +378,12 @@ void mpol_rebind_task(struct task_struct *tsk, const nodemask_t *new)
void mpol_rebind_mm(struct mm_struct *mm, nodemask_t *new)
{
struct vm_area_struct *vma;
+ DEFINE_RANGE_LOCK_FULL(mmrange);

- down_write(&mm->mmap_sem);
+ mm_write_lock(mm, &mmrange);
for (vma = mm->mmap; vma; vma = vma->vm_next)
mpol_rebind_policy(vma->vm_policy, new);
- up_write(&mm->mmap_sem);
+ mm_write_unlock(mm, &mmrange);
}

static const struct mempolicy_operations mpol_ops[MPOL_MAX] = {
@@ -842,10 +843,10 @@ static long do_get_mempolicy(int *policy, nodemask_t *nmask,
* vma/shared policy at addr is NULL. We
* want to return MPOL_DEFAULT in this case.
*/
- down_read(&mm->mmap_sem);
+ mm_read_lock(mm, &mmrange);
vma = find_vma_intersection(mm, addr, addr+1);
if (!vma) {
- up_read(&mm->mmap_sem);
+ mm_read_unlock(mm, &mmrange);
return -EFAULT;
}
if (vma->vm_ops && vma->vm_ops->get_policy)
@@ -895,7 +896,7 @@ static long do_get_mempolicy(int *policy, nodemask_t *nmask,
out:
mpol_cond_put(pol);
if (vma)
- up_read(&current->mm->mmap_sem);
+ mm_read_unlock(current->mm, &mmrange);
return err;
}

@@ -992,7 +993,7 @@ int do_migrate_pages(struct mm_struct *mm, const nodemask_t *from,
if (err)
return err;

- down_read(&mm->mmap_sem);
+ mm_read_lock(mm, &mmrange);

/*
* Find a 'source' bit set in 'tmp' whose corresponding 'dest'
@@ -1073,7 +1074,7 @@ int do_migrate_pages(struct mm_struct *mm, const nodemask_t *from,
if (err < 0)
break;
}
- up_read(&mm->mmap_sem);
+ mm_read_unlock(mm, &mmrange);
if (err < 0)
return err;
return busy;
@@ -1195,12 +1196,12 @@ static long do_mbind(unsigned long start, unsigned long len,
{
NODEMASK_SCRATCH(scratch);
if (scratch) {
- down_write(&mm->mmap_sem);
+ mm_write_lock(mm, &mmrange);
task_lock(current);
err = mpol_set_nodemask(new, nmask, scratch);
task_unlock(current);
if (err)
- up_write(&mm->mmap_sem);
+ mm_write_unlock(mm, &mmrange);
} else
err = -ENOMEM;
NODEMASK_SCRATCH_FREE(scratch);
@@ -1229,7 +1230,7 @@ static long do_mbind(unsigned long start, unsigned long len,
} else
putback_movable_pages(&pagelist);

- up_write(&mm->mmap_sem);
+ mm_write_unlock(mm, &mmrange);
mpol_out:
mpol_put(new);
return err;
diff --git a/mm/migrate.c b/mm/migrate.c
index 7a6afc34dd54..e905d2aef7fa 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -1486,8 +1486,9 @@ static int add_page_for_migration(struct mm_struct *mm, unsigned long addr,
struct page *page;
unsigned int follflags;
int err;
+ DEFINE_RANGE_LOCK_FULL(mmrange);

- down_read(&mm->mmap_sem);
+ mm_read_lock(mm, &mmrange);
err = -EFAULT;
vma = find_vma(mm, addr);
if (!vma || addr < vma->vm_start || !vma_migratable(vma))
@@ -1540,7 +1541,7 @@ static int add_page_for_migration(struct mm_struct *mm, unsigned long addr,
*/
put_page(page);
out:
- up_read(&mm->mmap_sem);
+ mm_read_unlock(mm, &mmrange);
return err;
}

@@ -1638,8 +1639,9 @@ static void do_pages_stat_array(struct mm_struct *mm, unsigned long nr_pages,
const void __user **pages, int *status)
{
unsigned long i;
+ DEFINE_RANGE_LOCK_FULL(mmrange);

- down_read(&mm->mmap_sem);
+ mm_read_lock(mm, &mmrange);

for (i = 0; i < nr_pages; i++) {
unsigned long addr = (unsigned long)(*pages);
@@ -1666,7 +1668,7 @@ static void do_pages_stat_array(struct mm_struct *mm, unsigned long nr_pages,
status++;
}

- up_read(&mm->mmap_sem);
+ mm_read_unlock(mm, &mmrange);
}

/*
diff --git a/mm/mincore.c b/mm/mincore.c
index a6875a34aac0..1255098449b8 100644
--- a/mm/mincore.c
+++ b/mm/mincore.c
@@ -259,9 +259,9 @@ SYSCALL_DEFINE3(mincore, unsigned long, start, size_t, len,
* Do at most PAGE_SIZE entries per iteration, due to
* the temporary buffer size.
*/
- down_read(&current->mm->mmap_sem);
+ mm_read_lock(current->mm, &mmrange);
retval = do_mincore(start, min(pages, PAGE_SIZE), tmp, &mmrange);
- up_read(&current->mm->mmap_sem);
+ mm_read_unlock(current->mm, &mmrange);

if (retval <= 0)
break;
diff --git a/mm/mmap.c b/mm/mmap.c
index 8f0eb88a5d5e..e10d005f7e2f 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -191,7 +191,7 @@ SYSCALL_DEFINE1(brk, unsigned long, brk)
LIST_HEAD(uf);
DEFINE_RANGE_LOCK_FULL(mmrange);

- if (down_write_killable(&mm->mmap_sem))
+ if (mm_write_lock_killable(mm, &mmrange))
return -EINTR;

#ifdef CONFIG_COMPAT_BRK
@@ -244,7 +244,7 @@ SYSCALL_DEFINE1(brk, unsigned long, brk)
set_brk:
mm->brk = brk;
populate = newbrk > oldbrk && (mm->def_flags & VM_LOCKED) != 0;
- up_write(&mm->mmap_sem);
+ mm_write_unlock(mm, &mmrange);
userfaultfd_unmap_complete(mm, &uf);
if (populate)
mm_populate(oldbrk, newbrk - oldbrk);
@@ -252,7 +252,7 @@ SYSCALL_DEFINE1(brk, unsigned long, brk)

out:
retval = mm->brk;
- up_write(&mm->mmap_sem);
+ mm_write_unlock(mm, &mmrange);
return retval;
}

@@ -2762,11 +2762,11 @@ int vm_munmap(unsigned long start, size_t len)
LIST_HEAD(uf);
DEFINE_RANGE_LOCK_FULL(mmrange);

- if (down_write_killable(&mm->mmap_sem))
+ if (mm_write_lock_killable(mm, &mmrange))
return -EINTR;

ret = do_munmap(mm, start, len, &uf, &mmrange);
- up_write(&mm->mmap_sem);
+ mm_write_unlock(mm, &mmrange);
userfaultfd_unmap_complete(mm, &uf);
return ret;
}
@@ -2808,7 +2808,7 @@ SYSCALL_DEFINE5(remap_file_pages, unsigned long, start, unsigned long, size,
if (pgoff + (size >> PAGE_SHIFT) < pgoff)
return ret;

- if (down_write_killable(&mm->mmap_sem))
+ if (mm_write_lock_killable(mm, &mmrange))
return -EINTR;

vma = find_vma(mm, start);
@@ -2871,7 +2871,7 @@ SYSCALL_DEFINE5(remap_file_pages, unsigned long, start, unsigned long, size,
prot, flags, pgoff, &populate, NULL, &mmrange);
fput(file);
out:
- up_write(&mm->mmap_sem);
+ mm_write_unlock(mm, &mmrange);
if (populate)
mm_populate(ret, populate);
if (!IS_ERR_VALUE(ret))
@@ -2882,9 +2882,11 @@ SYSCALL_DEFINE5(remap_file_pages, unsigned long, start, unsigned long, size,
static inline void verify_mm_writelocked(struct mm_struct *mm)
{
#ifdef CONFIG_DEBUG_VM
- if (unlikely(down_read_trylock(&mm->mmap_sem))) {
+ DEFINE_RANGE_LOCK_FULL(mmrange);
+
+ if (unlikely(mm_read_trylock(mm, &mmrange))) {
WARN_ON(1);
- up_read(&mm->mmap_sem);
+ mm_read_unlock(mm, &mmrange);
}
#endif
}
@@ -2996,12 +2998,12 @@ int vm_brk_flags(unsigned long addr, unsigned long len, unsigned long flags)
LIST_HEAD(uf);
DEFINE_RANGE_LOCK_FULL(mmrange);

- if (down_write_killable(&mm->mmap_sem))
+ if (mm_write_lock_killable(mm, &mmrange))
return -EINTR;

ret = do_brk_flags(addr, len, flags, &uf, &mmrange);
populate = ((mm->def_flags & VM_LOCKED) != 0);
- up_write(&mm->mmap_sem);
+ mm_write_unlock(mm, &mmrange);
userfaultfd_unmap_complete(mm, &uf);
if (populate && !ret)
mm_populate(addr, len);
@@ -3048,6 +3050,8 @@ void exit_mmap(struct mm_struct *mm)
unmap_vmas(&tlb, vma, 0, -1);

if (unlikely(mm_is_oom_victim(mm))) {
+ DEFINE_RANGE_LOCK_FULL(mmrange);
+
/*
* Wait for oom_reap_task() to stop working on this
* mm. Because MMF_OOM_SKIP is already set before
@@ -3061,8 +3065,8 @@ void exit_mmap(struct mm_struct *mm)
* is found not NULL while holding the task_lock.
*/
set_bit(MMF_OOM_SKIP, &mm->flags);
- down_write(&mm->mmap_sem);
- up_write(&mm->mmap_sem);
+ mm_write_lock(mm, &mmrange);
+ mm_write_unlock(mm, &mmrange);
}
free_pgtables(&tlb, vma, FIRST_USER_ADDRESS, USER_PGTABLES_CEILING);
tlb_finish_mmu(&tlb, 0, -1);
diff --git a/mm/mprotect.c b/mm/mprotect.c
index b84a70720319..2f39450ae959 100644
--- a/mm/mprotect.c
+++ b/mm/mprotect.c
@@ -424,7 +424,7 @@ static int do_mprotect_pkey(unsigned long start, size_t len,

reqprot = prot;

- if (down_write_killable(&current->mm->mmap_sem))
+ if (mm_write_lock_killable(current->mm, &mmrange))
return -EINTR;

/*
@@ -514,7 +514,7 @@ static int do_mprotect_pkey(unsigned long start, size_t len,
prot = reqprot;
}
out:
- up_write(&current->mm->mmap_sem);
+ mm_write_unlock(current->mm, &mmrange);
return error;
}

@@ -536,6 +536,7 @@ SYSCALL_DEFINE2(pkey_alloc, unsigned long, flags, unsigned long, init_val)
{
int pkey;
int ret;
+ DEFINE_RANGE_LOCK_FULL(mmrange);

/* No flags supported yet. */
if (flags)
@@ -544,7 +545,7 @@ SYSCALL_DEFINE2(pkey_alloc, unsigned long, flags, unsigned long, init_val)
if (init_val & ~PKEY_ACCESS_MASK)
return -EINVAL;

- down_write(&current->mm->mmap_sem);
+ mm_write_lock(current->mm, &mmrange);
pkey = mm_pkey_alloc(current->mm);

ret = -ENOSPC;
@@ -558,17 +559,18 @@ SYSCALL_DEFINE2(pkey_alloc, unsigned long, flags, unsigned long, init_val)
}
ret = pkey;
out:
- up_write(&current->mm->mmap_sem);
+ mm_write_unlock(current->mm, &mmrange);
return ret;
}

SYSCALL_DEFINE1(pkey_free, int, pkey)
{
int ret;
+ DEFINE_RANGE_LOCK_FULL(mmrange);

- down_write(&current->mm->mmap_sem);
+ mm_write_lock(current->mm, &mmrange);
ret = mm_pkey_free(current->mm, pkey);
- up_write(&current->mm->mmap_sem);
+ mm_write_unlock(current->mm, &mmrange);

/*
* We could provie warnings or errors if any VMA still
diff --git a/mm/mremap.c b/mm/mremap.c
index 21a9e2a2baa2..cc56d13e5e67 100644
--- a/mm/mremap.c
+++ b/mm/mremap.c
@@ -557,7 +557,7 @@ SYSCALL_DEFINE5(mremap, unsigned long, addr, unsigned long, old_len,
if (!new_len)
return ret;

- if (down_write_killable(&current->mm->mmap_sem))
+ if (mm_write_lock_killable(current->mm, &mmrange))
return -EINTR;

if (flags & MREMAP_FIXED) {
@@ -641,7 +641,7 @@ SYSCALL_DEFINE5(mremap, unsigned long, addr, unsigned long, old_len,
vm_unacct_memory(charged);
locked = 0;
}
- up_write(&current->mm->mmap_sem);
+ mm_write_unlock(current->mm, &mmrange);
if (locked && new_len > old_len)
mm_populate(new_addr + old_len, new_len - old_len);
userfaultfd_unmap_complete(mm, &uf_unmap_early);
diff --git a/mm/msync.c b/mm/msync.c
index ef30a429623a..2524b4708e78 100644
--- a/mm/msync.c
+++ b/mm/msync.c
@@ -36,6 +36,7 @@ SYSCALL_DEFINE3(msync, unsigned long, start, size_t, len, int, flags)
struct vm_area_struct *vma;
int unmapped_error = 0;
int error = -EINVAL;
+ DEFINE_RANGE_LOCK_FULL(mmrange);

if (flags & ~(MS_ASYNC | MS_INVALIDATE | MS_SYNC))
goto out;
@@ -55,7 +56,7 @@ SYSCALL_DEFINE3(msync, unsigned long, start, size_t, len, int, flags)
* If the interval [start,end) covers some unmapped address ranges,
* just ignore them, but return -ENOMEM at the end.
*/
- down_read(&mm->mmap_sem);
+ mm_read_lock(mm, &mmrange);
vma = find_vma(mm, start);
for (;;) {
struct file *file;
@@ -86,12 +87,12 @@ SYSCALL_DEFINE3(msync, unsigned long, start, size_t, len, int, flags)
if ((flags & MS_SYNC) && file &&
(vma->vm_flags & VM_SHARED)) {
get_file(file);
- up_read(&mm->mmap_sem);
+ mm_read_unlock(mm, &mmrange);
error = vfs_fsync_range(file, fstart, fend, 1);
fput(file);
if (error || start >= end)
goto out;
- down_read(&mm->mmap_sem);
+ mm_read_lock(mm, &mmrange);
vma = find_vma(mm, start);
} else {
if (start >= end) {
@@ -102,7 +103,7 @@ SYSCALL_DEFINE3(msync, unsigned long, start, size_t, len, int, flags)
}
}
out_unlock:
- up_read(&mm->mmap_sem);
+ mm_read_unlock(mm, &mmrange);
out:
return error ? : unmapped_error;
}
diff --git a/mm/nommu.c b/mm/nommu.c
index 1805f0a788b3..575525e86961 100644
--- a/mm/nommu.c
+++ b/mm/nommu.c
@@ -187,10 +187,10 @@ static long __get_user_pages_unlocked(struct task_struct *tsk,
long ret;
DEFINE_RANGE_LOCK_FULL(mmrange);

- down_read(&mm->mmap_sem);
+ mm_read_lock(mm, &mmrange);
ret = __get_user_pages(tsk, mm, start, nr_pages, gup_flags, pages,
NULL, NULL, &mmrange);
- up_read(&mm->mmap_sem);
+ mm_read_unlock(mm, &mmrange);
return ret;
}

@@ -253,12 +253,13 @@ void *vmalloc_user(unsigned long size)
ret = __vmalloc(size, GFP_KERNEL | __GFP_ZERO, PAGE_KERNEL);
if (ret) {
struct vm_area_struct *vma;
+ DEFINE_RANGE_LOCK_FULL(mmrange);

- down_write(&current->mm->mmap_sem);
+ mm_write_lock(current->mm, &mmrange);
vma = find_vma(current->mm, (unsigned long)ret);
if (vma)
vma->vm_flags |= VM_USERMAP;
- up_write(&current->mm->mmap_sem);
+ mm_write_unlock(current->mm, &mmrange);
}

return ret;
@@ -1651,9 +1652,9 @@ int vm_munmap(unsigned long addr, size_t len)
int ret;
DEFINE_RANGE_LOCK_FULL(mmrange);

- down_write(&mm->mmap_sem);
+ mm_write_lock(mm, &mmrange);
ret = do_munmap(mm, addr, len, NULL, &mmrange);
- up_write(&mm->mmap_sem);
+ mm_write_unlock(mm, &mmrange);
return ret;
}
EXPORT_SYMBOL(vm_munmap);
@@ -1739,10 +1740,11 @@ SYSCALL_DEFINE5(mremap, unsigned long, addr, unsigned long, old_len,
unsigned long, new_addr)
{
unsigned long ret;
+ DEFINE_RANGE_LOCK_FULL(mmrange);

- down_write(&current->mm->mmap_sem);
+ mm_write_lock(current->mm, &mmrange);
ret = do_mremap(addr, old_len, new_len, flags, new_addr);
- up_write(&current->mm->mmap_sem);
+ mm_write_unlock(current->mm, &mmrange);
return ret;
}

@@ -1815,8 +1817,9 @@ int __access_remote_vm(struct task_struct *tsk, struct mm_struct *mm,
{
struct vm_area_struct *vma;
int write = gup_flags & FOLL_WRITE;
+ DEFINE_RANGE_LOCK_FULL(mmrange);

- down_read(&mm->mmap_sem);
+ mm_read_lock(mm, &mmrange);

/* the access must start within one of the target process's mappings */
vma = find_vma(mm, addr);
@@ -1838,7 +1841,7 @@ int __access_remote_vm(struct task_struct *tsk, struct mm_struct *mm,
len = 0;
}

- up_read(&mm->mmap_sem);
+ mm_read_unlock(mm, &mmrange);

return len;
}
diff --git a/mm/oom_kill.c b/mm/oom_kill.c
index 2288e1cb1bc9..6bf9cb38bfe1 100644
--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -508,7 +508,7 @@ static bool __oom_reap_task_mm(struct task_struct *tsk, struct mm_struct *mm)
*/
mutex_lock(&oom_lock);

- if (!down_read_trylock(&mm->mmap_sem)) {
+ if (!mm_read_trylock(mm, &mmrange)) {
ret = false;
trace_skip_task_reaping(tsk->pid);
goto unlock_oom;
@@ -521,7 +521,7 @@ static bool __oom_reap_task_mm(struct task_struct *tsk, struct mm_struct *mm)
* notifiers cannot block for unbounded amount of time
*/
if (mm_has_blockable_invalidate_notifiers(mm, &mmrange)) {
- up_read(&mm->mmap_sem);
+ mm_read_unlock(mm, &mmrange);
schedule_timeout_idle(HZ);
goto unlock_oom;
}
@@ -533,7 +533,7 @@ static bool __oom_reap_task_mm(struct task_struct *tsk, struct mm_struct *mm)
* down_write();up_write() cycle in exit_mmap().
*/
if (test_bit(MMF_OOM_SKIP, &mm->flags)) {
- up_read(&mm->mmap_sem);
+ mm_read_unlock(mm, &mmrange);
trace_skip_task_reaping(tsk->pid);
goto unlock_oom;
}
@@ -578,7 +578,7 @@ static bool __oom_reap_task_mm(struct task_struct *tsk, struct mm_struct *mm)
K(get_mm_counter(mm, MM_ANONPAGES)),
K(get_mm_counter(mm, MM_FILEPAGES)),
K(get_mm_counter(mm, MM_SHMEMPAGES)));
- up_read(&mm->mmap_sem);
+ mm_read_unlock(mm, &mmrange);

trace_finish_task_reaping(tsk->pid);
unlock_oom:
diff --git a/mm/pagewalk.c b/mm/pagewalk.c
index 44a2507c94fd..55a4dcc519cd 100644
--- a/mm/pagewalk.c
+++ b/mm/pagewalk.c
@@ -301,7 +301,7 @@ int walk_page_range(unsigned long start, unsigned long end,
if (!walk->mm)
return -EINVAL;

- VM_BUG_ON_MM(!rwsem_is_locked(&walk->mm->mmap_sem), walk->mm);
+ VM_BUG_ON_MM(!mm_is_locked(walk->mm, mmrange), walk->mm);

vma = find_vma(walk->mm, start);
do {
@@ -345,7 +345,7 @@ int walk_page_vma(struct vm_area_struct *vma, struct mm_walk *walk,
if (!walk->mm)
return -EINVAL;

- VM_BUG_ON(!rwsem_is_locked(&walk->mm->mmap_sem));
+ VM_BUG_ON(!mm_is_locked(walk->mm, mmrange));
VM_BUG_ON(!vma);
walk->vma = vma;
err = walk_page_test(vma->vm_start, vma->vm_end, walk, mmrange);
diff --git a/mm/process_vm_access.c b/mm/process_vm_access.c
index ff6772b86195..aaccb8972f83 100644
--- a/mm/process_vm_access.c
+++ b/mm/process_vm_access.c
@@ -110,12 +110,12 @@ static int process_vm_rw_single_vec(unsigned long addr,
* access remotely because task/mm might not
* current/current->mm
*/
- down_read(&mm->mmap_sem);
+ mm_read_lock(mm, &mmrange);
pages = get_user_pages_remote(task, mm, pa, pages, flags,
process_pages, NULL, &locked,
&mmrange);
if (locked)
- up_read(&mm->mmap_sem);
+ mm_read_unlock(mm, &mmrange);
if (pages <= 0)
return -EFAULT;

diff --git a/mm/shmem.c b/mm/shmem.c
index 1907688b75ee..8a99281bf502 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -1961,7 +1961,7 @@ static int shmem_fault(struct vm_fault *vmf)
if ((vmf->flags & FAULT_FLAG_ALLOW_RETRY) &&
!(vmf->flags & FAULT_FLAG_RETRY_NOWAIT)) {
/* It's polite to up mmap_sem if we can */
- up_read(&vma->vm_mm->mmap_sem);
+ mm_read_unlock(vma->vm_mm, vmf->lockrange);
ret = VM_FAULT_RETRY;
}

diff --git a/mm/swapfile.c b/mm/swapfile.c
index 006047b16814..d9c6ca32b94f 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -1958,15 +1958,16 @@ static int unuse_mm(struct mm_struct *mm,
{
struct vm_area_struct *vma;
int ret = 0;
+ DEFINE_RANGE_LOCK_FULL(mmrange);

- if (!down_read_trylock(&mm->mmap_sem)) {
+ if (!mm_read_trylock(mm, &mmrange)) {
/*
* Activate page so shrink_inactive_list is unlikely to unmap
* its ptes while lock is dropped, so swapoff can make progress.
*/
activate_page(page);
unlock_page(page);
- down_read(&mm->mmap_sem);
+ mm_read_lock(mm, &mmrange);
lock_page(page);
}
for (vma = mm->mmap; vma; vma = vma->vm_next) {
@@ -1974,7 +1975,7 @@ static int unuse_mm(struct mm_struct *mm,
break;
cond_resched();
}
- up_read(&mm->mmap_sem);
+ mm_read_unlock(mm, &mmrange);
return (ret < 0)? ret: 0;
}

diff --git a/mm/userfaultfd.c b/mm/userfaultfd.c
index 39791b81ede7..8ad13bea799d 100644
--- a/mm/userfaultfd.c
+++ b/mm/userfaultfd.c
@@ -155,7 +155,8 @@ static __always_inline ssize_t __mcopy_atomic_hugetlb(struct mm_struct *dst_mm,
unsigned long dst_start,
unsigned long src_start,
unsigned long len,
- bool zeropage)
+ bool zeropage,
+ struct range_lock *mmrange)
{
int vm_alloc_shared = dst_vma->vm_flags & VM_SHARED;
int vm_shared = dst_vma->vm_flags & VM_SHARED;
@@ -177,7 +178,7 @@ static __always_inline ssize_t __mcopy_atomic_hugetlb(struct mm_struct *dst_mm,
* feature is not supported.
*/
if (zeropage) {
- up_read(&dst_mm->mmap_sem);
+ mm_read_unlock(dst_mm, mmrange);
return -EINVAL;
}

@@ -275,7 +276,7 @@ static __always_inline ssize_t __mcopy_atomic_hugetlb(struct mm_struct *dst_mm,
cond_resched();

if (unlikely(err == -EFAULT)) {
- up_read(&dst_mm->mmap_sem);
+ mm_read_unlock(dst_mm, mmrange);
BUG_ON(!page);

err = copy_huge_page_from_user(page,
@@ -285,7 +286,7 @@ static __always_inline ssize_t __mcopy_atomic_hugetlb(struct mm_struct *dst_mm,
err = -EFAULT;
goto out;
}
- down_read(&dst_mm->mmap_sem);
+ mm_read_lock(dst_mm, mmrange);

dst_vma = NULL;
goto retry;
@@ -305,7 +306,7 @@ static __always_inline ssize_t __mcopy_atomic_hugetlb(struct mm_struct *dst_mm,
}

out_unlock:
- up_read(&dst_mm->mmap_sem);
+ mm_read_unlock(dst_mm, mmrange);
out:
if (page) {
/*
@@ -367,7 +368,8 @@ extern ssize_t __mcopy_atomic_hugetlb(struct mm_struct *dst_mm,
unsigned long dst_start,
unsigned long src_start,
unsigned long len,
- bool zeropage);
+ bool zeropage,
+ struct range_lock *mmrange);
#endif /* CONFIG_HUGETLB_PAGE */

static __always_inline ssize_t mfill_atomic_pte(struct mm_struct *dst_mm,
@@ -412,6 +414,7 @@ static __always_inline ssize_t __mcopy_atomic(struct mm_struct *dst_mm,
unsigned long src_addr, dst_addr;
long copied;
struct page *page;
+ DEFINE_RANGE_LOCK_FULL(mmrange);

/*
* Sanitize the command parameters:
@@ -428,7 +431,7 @@ static __always_inline ssize_t __mcopy_atomic(struct mm_struct *dst_mm,
copied = 0;
page = NULL;
retry:
- down_read(&dst_mm->mmap_sem);
+ mm_read_lock(dst_mm, &mmrange);

/*
* Make sure the vma is not shared, that the dst range is
@@ -468,7 +471,8 @@ static __always_inline ssize_t __mcopy_atomic(struct mm_struct *dst_mm,
*/
if (is_vm_hugetlb_page(dst_vma))
return __mcopy_atomic_hugetlb(dst_mm, dst_vma, dst_start,
- src_start, len, zeropage);
+ src_start, len, zeropage,
+ &mmrange);

if (!vma_is_anonymous(dst_vma) && !vma_is_shmem(dst_vma))
goto out_unlock;
@@ -523,7 +527,7 @@ static __always_inline ssize_t __mcopy_atomic(struct mm_struct *dst_mm,
if (unlikely(err == -EFAULT)) {
void *page_kaddr;

- up_read(&dst_mm->mmap_sem);
+ mm_read_unlock(dst_mm, &mmrange);
BUG_ON(!page);

page_kaddr = kmap(page);
@@ -552,7 +556,7 @@ static __always_inline ssize_t __mcopy_atomic(struct mm_struct *dst_mm,
}

out_unlock:
- up_read(&dst_mm->mmap_sem);
+ mm_read_unlock(dst_mm, &mmrange);
out:
if (page)
put_page(page);
diff --git a/mm/util.c b/mm/util.c
index b0ec1d88bb71..e17c6c74cc23 100644
--- a/mm/util.c
+++ b/mm/util.c
@@ -351,11 +351,11 @@ unsigned long vm_mmap_pgoff(struct file *file, unsigned long addr,

ret = security_mmap_file(file, prot, flag);
if (!ret) {
- if (down_write_killable(&mm->mmap_sem))
+ if (mm_write_lock_killable(mm, &mmrange))
return -EINTR;
ret = do_mmap_pgoff(file, addr, len, prot, flag, pgoff,
&populate, &uf, &mmrange);
- up_write(&mm->mmap_sem);
+ mm_write_unlock(mm, &mmrange);
userfaultfd_unmap_complete(mm, &uf);
if (populate)
mm_populate(ret, populate);
@@ -715,18 +715,19 @@ int get_cmdline(struct task_struct *task, char *buffer, int buflen)
int res = 0;
unsigned int len;
struct mm_struct *mm = get_task_mm(task);
+ DEFINE_RANGE_LOCK_FULL(mmrange);
unsigned long arg_start, arg_end, env_start, env_end;
if (!mm)
goto out;
if (!mm->arg_end)
goto out_mm; /* Shh! No looking before we're done */

- down_read(&mm->mmap_sem);
+ mm_read_lock(mm, &mmrange);
arg_start = mm->arg_start;
arg_end = mm->arg_end;
env_start = mm->env_start;
env_end = mm->env_end;
- up_read(&mm->mmap_sem);
+ mm_read_unlock(mm, &mmrange);

len = arg_end - arg_start;

--
2.13.6