diff --git a/mm/fremap.c b/mm/fremap.c
index 7881638e4a12bd8c5489c8d08b5779b5ae5a0080..7d12ca70ef7bf22c7e1efcdee186adad87a6c8c8 100644
--- a/mm/fremap.c
+++ b/mm/fremap.c
@@ -21,6 +21,8 @@
#include <asm/cacheflush.h>
#include <asm/tlbflush.h>
+#include "internal.h"
+
static void zap_pte(struct mm_struct *mm, struct vm_area_struct *vma,
unsigned long addr, pte_t *ptep)
{
@@ -215,15 +217,31 @@ asmlinkage long sys_remap_file_pages(unsigned long start, unsigned long size,
spin_unlock(&mapping->i_mmap_lock);
}
+ if (vma->vm_flags & VM_LOCKED) {
+ /*
+ * drop PG_Mlocked flag for over-mapped range
+ */
+ unsigned int saved_flags = vma->vm_flags;
+ munlock_vma_pages_range(vma, start, start + size);
+ vma->vm_flags = saved_flags;
+ }
+
mmu_notifier_invalidate_range_start(mm, start, start + size);
err = populate_range(mm, vma, start, size, pgoff);
mmu_notifier_invalidate_range_end(mm, start, start + size);
if (!err && !(flags & MAP_NONBLOCK)) {
- if (unlikely(has_write_lock)) {
- downgrade_write(&mm->mmap_sem);
- has_write_lock = 0;
+ if (vma->vm_flags & VM_LOCKED) {
+ /*
+ * might be mapping previously unmapped range of file
+ */
+ mlock_vma_pages_range(vma, start, start + size);
+ } else {
+ if (unlikely(has_write_lock)) {
+ downgrade_write(&mm->mmap_sem);
+ has_write_lock = 0;
+ }
+ make_pages_present(start, start+size);
}
- make_pages_present(start, start+size);
}
/*
@@ -240,4 +258,3 @@ asmlinkage long sys_remap_file_pages(unsigned long start, unsigned long size,
return err;
}
-
diff --git a/mm/internal.h b/mm/internal.h
index 4ebf0bef9a39f0bed64dd40e3167ae02b7891446..48e32f790571f8868e69771e2c91c8c2fd3a34ae 100644
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -61,9 +61,14 @@ static inline unsigned long page_order(struct page *page)
return page_private(page);
}
-extern int mlock_vma_pages_range(struct vm_area_struct *vma,
+extern long mlock_vma_pages_range(struct vm_area_struct *vma,
unsigned long start, unsigned long end);
-extern void munlock_vma_pages_all(struct vm_area_struct *vma);
+extern void munlock_vma_pages_range(struct vm_area_struct *vma,
+ unsigned long start, unsigned long end);
+static inline void munlock_vma_pages_all(struct vm_area_struct *vma)
+{
+ munlock_vma_pages_range(vma, vma->vm_start, vma->vm_end);
+}
#ifdef CONFIG_UNEVICTABLE_LRU
/*
diff --git a/mm/mlock.c b/mm/mlock.c
index c83896a725042d45694777305107fd33ba9c9c28..8b478350a2a1528487ea60113db54b5e6976a4cb 100644
--- a/mm/mlock.c
+++ b/mm/mlock.c
@@ -112,26 +112,49 @@ static void munlock_vma_page(struct page *page)
}
}
-/*
- * mlock a range of pages in the vma.
+/**
+ * __mlock_vma_pages_range() - mlock/munlock a range of pages in the vma.
+ * @vma: target vma
+ * @start: start address
+ * @end: end address
+ * @mlock: 0 indicate munlock, otherwise mlock.
+ *
+ * If @mlock == 0, unlock an mlocked range;
+ * else mlock the range of pages. This takes care of making the pages present ,
+ * too.
*
- * This takes care of making the pages present too.
+ * return 0 on success, negative error code on error.
*
- * vma->vm_mm->mmap_sem must be held for write.
+ * vma->vm_mm->mmap_sem must be held for at least read.
*/
-static int __mlock_vma_pages_range(struct vm_area_struct *vma,
- unsigned long start, unsigned long end)
+static long __mlock_vma_pages_range(struct vm_area_struct *vma,
+ unsigned long start, unsigned long end,
+ int mlock)
{
struct mm_struct *mm = vma->vm_mm;
unsigned long addr = start;
struct page *pages[16]; /* 16 gives a reasonable batch */
- int write = !!(vma->vm_flags & VM_WRITE);
int nr_pages = (end - start) / PAGE_SIZE;
int ret;
+ int gup_flags = 0;
- VM_BUG_ON(start & ~PAGE_MASK || end & ~PAGE_MASK);
- VM_BUG_ON(start < vma->vm_start || end > vma->vm_end);
- VM_BUG_ON(!rwsem_is_locked(&vma->vm_mm->mmap_sem));
+ VM_BUG_ON(start & ~PAGE_MASK);
+ VM_BUG_ON(end & ~PAGE_MASK);
+ VM_BUG_ON(start < vma->vm_start);
+ VM_BUG_ON(end > vma->vm_end);
+ VM_BUG_ON((!rwsem_is_locked(&mm->mmap_sem)) &&
+ (atomic_read(&mm->mm_users) != 0));
+
+ /*
+ * mlock: don't page populate if page has PROT_NONE permission.
+ * munlock: the pages always do munlock althrough
+ * its has PROT_NONE permission.
+ */
+ if (!mlock)
+ gup_flags |= GUP_FLAGS_IGNORE_VMA_PERMISSIONS;
+
+ if (vma->vm_flags & VM_WRITE)
+ gup_flags |= GUP_FLAGS_WRITE;
lru_add_drain_all(); /* push cached pages to LRU */
@@ -146,9 +169,9 @@ static int __mlock_vma_pages_range(struct vm_area_struct *vma,
* disable migration of this page. However, page may
* still be truncated out from under us.
*/
- ret = get_user_pages(current, mm, addr,
+ ret = __get_user_pages(current, mm, addr,
min_t(int, nr_pages, ARRAY_SIZE(pages)),
- write, 0, pages, NULL);
+ gup_flags, pages, NULL);
/*
* This can happen for, e.g., VM_NONLINEAR regions before
* a page has been allocated and mapped at a given offset,
@@ -178,8 +201,12 @@ static int __mlock_vma_pages_range(struct vm_area_struct *vma,
* by the elevated reference, we need only check for
* page truncation (file-cache only).
*/
- if (page->mapping)
- mlock_vma_page(page);
+ if (page->mapping) {
+ if (mlock)
+ mlock_vma_page(page);
+ else
+ munlock_vma_page(page);
+ }
unlock_page(page);
put_page(page); /* ref from get_user_pages() */
@@ -197,125 +224,38 @@ static int __mlock_vma_pages_range(struct vm_area_struct *vma,
return 0; /* count entire vma as locked_vm */
}
-/*
- * private structure for munlock page table walk
- */
-struct munlock_page_walk {
- struct vm_area_struct *vma;
- pmd_t *pmd; /* for migration_entry_wait() */
-};
-
-/*
- * munlock normal pages for present ptes
- */
-static int __munlock_pte_handler(pte_t *ptep, unsigned long addr,
- unsigned long end, struct mm_walk *walk)
-{
- struct munlock_page_walk *mpw = walk->private;
- swp_entry_t entry;
- struct page *page;
- pte_t pte;
-
-retry:
- pte = *ptep;
- /*
- * If it's a swap pte, we might be racing with page migration.
- */
- if (unlikely(!pte_present(pte))) {
- if (!is_swap_pte(pte))
- goto out;
- entry = pte_to_swp_entry(pte);
- if (is_migration_entry(entry)) {
- migration_entry_wait(mpw->vma->vm_mm, mpw->pmd, addr);
- goto retry;
- }
- goto out;
- }
-
- page = vm_normal_page(mpw->vma, addr, pte);
- if (!page)
- goto out;
-
- lock_page(page);
- if (!page->mapping) {
- unlock_page(page);
- goto retry;
- }
- munlock_vma_page(page);
- unlock_page(page);
-
-out:
- return 0;
-}
-
-/*
- * Save pmd for pte handler for waiting on migration entries
- */
-static int __munlock_pmd_handler(pmd_t *pmd, unsigned long addr,
- unsigned long end, struct mm_walk *walk)
-{
- struct munlock_page_walk *mpw = walk->private;
-
- mpw->pmd = pmd;
- return 0;
-}
-
-
-/*
- * munlock a range of pages in the vma using standard page table walk.
- *
- * vma->vm_mm->mmap_sem must be held for write.
- */
-static void __munlock_vma_pages_range(struct vm_area_struct *vma,
- unsigned long start, unsigned long end)
-{
- struct mm_struct *mm = vma->vm_mm;
- struct munlock_page_walk mpw = {
- .vma = vma,
- };
- struct mm_walk munlock_page_walk = {
- .pmd_entry = __munlock_pmd_handler,
- .pte_entry = __munlock_pte_handler,
- .private = &mpw,
- .mm = mm,
- };
-
- VM_BUG_ON(start & ~PAGE_MASK || end & ~PAGE_MASK);
- VM_BUG_ON(!rwsem_is_locked(&vma->vm_mm->mmap_sem));
- VM_BUG_ON(start < vma->vm_start);
- VM_BUG_ON(end > vma->vm_end);
-
- lru_add_drain_all(); /* push cached pages to LRU */
- walk_page_range(start, end, &munlock_page_walk);
- lru_add_drain_all(); /* to update stats */
-}
-
#else /* CONFIG_UNEVICTABLE_LRU */
/*
* Just make pages present if VM_LOCKED. No-op if unlocking.
*/
-static int __mlock_vma_pages_range(struct vm_area_struct *vma,
- unsigned long start, unsigned long end)
+static long __mlock_vma_pages_range(struct vm_area_struct *vma,
+ unsigned long start, unsigned long end,
+ int mlock)
{
- if (vma->vm_flags & VM_LOCKED)
+ if (mlock && (vma->vm_flags & VM_LOCKED))
make_pages_present(start, end);
return 0;
}
-
-/*
- * munlock a range of pages in the vma -- no-op.
- */
-static void __munlock_vma_pages_range(struct vm_area_struct *vma,
- unsigned long start, unsigned long end)
-{
-}
#endif /* CONFIG_UNEVICTABLE_LRU */
-/*
- * mlock all pages in this vma range. For mmap()/mremap()/...
+/**
+ * mlock_vma_pages_range() - mlock pages in specified vma range.
+ * @vma - the vma containing the specfied address range
+ * @start - starting address in @vma to mlock
+ * @end - end address [+1] in @vma to mlock
+ *
+ * For mmap()/mremap()/expansion of mlocked vma.
+ *
+ * return 0 on success for "normal" vmas.
+ *
+ * return number of pages [> 0] to be removed from locked_vm on success
+ * of "special" vmas.
+ *
+ * return negative error if vma spanning @start-@range disappears while
+ * mmap semaphore is dropped. Unlikely?
*/
-int mlock_vma_pages_range(struct vm_area_struct *vma,
+long mlock_vma_pages_range(struct vm_area_struct *vma,
unsigned long start, unsigned long end)
{
struct mm_struct *mm = vma->vm_mm;
@@ -331,8 +271,10 @@ int mlock_vma_pages_range(struct vm_area_struct *vma,
if (!((vma->vm_flags & (VM_DONTEXPAND | VM_RESERVED)) ||
is_vm_hugetlb_page(vma) ||
vma == get_gate_vma(current))) {
+ long error;
downgrade_write(&mm->mmap_sem);
- nr_pages = __mlock_vma_pages_range(vma, start, end);
+
+ error = __mlock_vma_pages_range(vma, start, end, 1);
up_read(&mm->mmap_sem);
/* vma can change or disappear */
@@ -340,8 +282,9 @@ int mlock_vma_pages_range(struct vm_area_struct *vma,
vma = find_vma(mm, start);
/* non-NULL vma must contain @start, but need to check @end */
if (!vma || end > vma->vm_end)
- return -EAGAIN;
- return nr_pages;
+ return -ENOMEM;
+
+ return 0; /* hide other errors from mmap(), et al */
}
/*
@@ -356,17 +299,33 @@ int mlock_vma_pages_range(struct vm_area_struct *vma,
no_mlock:
vma->vm_flags &= ~VM_LOCKED; /* and don't come back! */
- return nr_pages; /* pages NOT mlocked */
+ return nr_pages; /* error or pages NOT mlocked */
}
/*
- * munlock all pages in vma. For munmap() and exit().
+ * munlock_vma_pages_range() - munlock all pages in the vma range.'
+ * @vma - vma containing range to be munlock()ed.
+ * @start - start address in @vma of the range
+ * @end - end of range in @vma.
+ *
+ * For mremap(), munmap() and exit().
+ *
+ * Called with @vma VM_LOCKED.
+ *
+ * Returns with VM_LOCKED cleared. Callers must be prepared to
+ * deal with this.
+ *
+ * We don't save and restore VM_LOCKED here because pages are
+ * still on lru. In unmap path, pages might be scanned by reclaim
+ * and re-mlocked by try_to_{munlock|unmap} before we unmap and
+ * free them. This will result in freeing mlocked pages.
*/
-void munlock_vma_pages_all(struct vm_area_struct *vma)
+void munlock_vma_pages_range(struct vm_area_struct *vma,
+ unsigned long start, unsigned long end)
{
vma->vm_flags &= ~VM_LOCKED;
- __munlock_vma_pages_range(vma, vma->vm_start, vma->vm_end);
+ __mlock_vma_pages_range(vma, start, end, 0);
}
/*
@@ -443,7 +402,7 @@ static int mlock_fixup(struct vm_area_struct *vma, struct vm_area_struct **prev,
*/
downgrade_write(&mm->mmap_sem);
- ret = __mlock_vma_pages_range(vma, start, end);
+ ret = __mlock_vma_pages_range(vma, start, end, 1);
if (ret > 0) {
mm->locked_vm -= ret;
ret = 0;
@@ -460,7 +419,7 @@ static int mlock_fixup(struct vm_area_struct *vma, struct vm_area_struct **prev,
*prev = find_vma(mm, start);
/* non-NULL *prev must contain @start, but need to check @end */
if (!(*prev) || end > (*prev)->vm_end)
- ret = -EAGAIN;
+ ret = -ENOMEM;
} else {
/*
* TODO: for unlocking, pages will already be resident, so
@@ -469,7 +428,7 @@ static int mlock_fixup(struct vm_area_struct *vma, struct vm_area_struct **prev,
* while. Should we downgrade the semaphore for both lock
* AND unlock ?
*/
- __munlock_vma_pages_range(vma, start, end);
+ __mlock_vma_pages_range(vma, start, end, 0);
}
out:
diff --git a/mm/mmap.c b/mm/mmap.c
index 7bdfd2661f173a273d34eaeef7e93244d584990c..505a454f365e35074cf21f3bed2fb1066cb68c15 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -970,6 +970,7 @@ unsigned long do_mmap_pgoff(struct file * file, unsigned long addr,
return -EPERM;
vm_flags |= VM_LOCKED;
}
+
/* mlock MCL_FUTURE? */
if (vm_flags & VM_LOCKED) {
unsigned long locked, lock_limit;
@@ -1137,10 +1138,12 @@ unsigned long mmap_region(struct file *file, unsigned long addr,
* The VM_SHARED test is necessary because shmem_zero_setup
* will create the file object for a shared anonymous map below.
*/
- if (!file && !(vm_flags & VM_SHARED) &&
- vma_merge(mm, prev, addr, addr + len, vm_flags,
- NULL, NULL, pgoff, NULL))
- goto out;
+ if (!file && !(vm_flags & VM_SHARED)) {
+ vma = vma_merge(mm, prev, addr, addr + len, vm_flags,
+ NULL, NULL, pgoff, NULL);
+ if (vma)
+ goto out;
+ }
/*
* Determine the object being mapped and call the appropriate
@@ -1222,10 +1225,14 @@ unsigned long mmap_region(struct file *file, unsigned long addr,
mm->total_vm += len >> PAGE_SHIFT;
vm_stat_account(mm, vm_flags, file, len >> PAGE_SHIFT);
if (vm_flags & VM_LOCKED) {
- mm->locked_vm += len >> PAGE_SHIFT;
- make_pages_present(addr, addr + len);
- }
- if ((flags & MAP_POPULATE) && !(flags & MAP_NONBLOCK))
+ /*
+ * makes pages present; downgrades, drops, reacquires mmap_sem
+ */
+ long nr_pages = mlock_vma_pages_range(vma, addr, addr + len);
+ if (nr_pages < 0)
+ return nr_pages; /* vma gone! */
+ mm->locked_vm += (len >> PAGE_SHIFT) - nr_pages;
+ } else if ((flags & MAP_POPULATE) && !(flags & MAP_NONBLOCK))
make_pages_present(addr, addr + len);
return addr;
@@ -1698,8 +1705,10 @@ find_extend_vma(struct mm_struct *mm, unsigned long addr)
return vma;
if (!prev || expand_stack(prev, addr))
return NULL;
- if (prev->vm_flags & VM_LOCKED)
- make_pages_present(addr, prev->vm_end);
+ if (prev->vm_flags & VM_LOCKED) {
+ if (mlock_vma_pages_range(prev, addr, prev->vm_end) < 0)
+ return NULL; /* vma gone! */
+ }
return prev;
}
#else
@@ -1725,8 +1734,10 @@ find_extend_vma(struct mm_struct * mm, unsigned long addr)
start = vma->vm_start;
if (expand_stack(vma, addr))
return NULL;
- if (vma->vm_flags & VM_LOCKED)
- make_pages_present(addr, start);
+ if (vma->vm_flags & VM_LOCKED) {
+ if (mlock_vma_pages_range(vma, addr, start) < 0)
+ return NULL; /* vma gone! */
+ }
return vma;
}
#endif
@@ -1745,8 +1756,6 @@ static void remove_vma_list(struct mm_struct *mm, struct vm_area_struct *vma)
long nrpages = vma_pages(vma);
mm->total_vm -= nrpages;
- if (vma->vm_flags & VM_LOCKED)
- mm->locked_vm -= nrpages;
vm_stat_account(mm, vma->vm_flags, vma->vm_file, -nrpages);
vma = remove_vma(vma);
} while (vma);
@@ -1911,6 +1920,20 @@ int do_munmap(struct mm_struct *mm, unsigned long start, size_t len)
}
vma = prev? prev->vm_next: mm->mmap;
+ /*
+ * unlock any mlock()ed ranges before detaching vmas
+ */
+ if (mm->locked_vm) {
+ struct vm_area_struct *tmp = vma;
+ while (tmp && tmp->vm_start < end) {
+ if (tmp->vm_flags & VM_LOCKED) {
+ mm->locked_vm -= vma_pages(tmp);
+ munlock_vma_pages_all(tmp);
+ }
+ tmp = tmp->vm_next;
+ }
+ }
+
/*
* Remove the vma's, and unmap the actual pages
*/
@@ -2023,8 +2046,9 @@ unsigned long do_brk(unsigned long addr, unsigned long len)
return -ENOMEM;
/* Can we just expand an old private anonymous mapping? */
- if (vma_merge(mm, prev, addr, addr + len, flags,
- NULL, NULL, pgoff, NULL))
+ vma = vma_merge(mm, prev, addr, addr + len, flags,
+ NULL, NULL, pgoff, NULL);
+ if (vma)
goto out;
/*
@@ -2046,8 +2070,8 @@ unsigned long do_brk(unsigned long addr, unsigned long len)
out:
mm->total_vm += len >> PAGE_SHIFT;
if (flags & VM_LOCKED) {
- mm->locked_vm += len >> PAGE_SHIFT;
- make_pages_present(addr, addr + len);
+ if (!mlock_vma_pages_range(vma, addr, addr + len))
+ mm->locked_vm += (len >> PAGE_SHIFT);
}
return addr;
}
@@ -2058,7 +2082,7 @@ EXPORT_SYMBOL(do_brk);
void exit_mmap(struct mm_struct *mm)
{
struct mmu_gather *tlb;
- struct vm_area_struct *vma = mm->mmap;
+ struct vm_area_struct *vma;
unsigned long nr_accounted = 0;
unsigned long end;
@@ -2066,6 +2090,15 @@ void exit_mmap(struct mm_struct *mm)
arch_exit_mmap(mm);
mmu_notifier_release(mm);
+ if (mm->locked_vm) {
+ vma = mm->mmap;
+ while (vma) {
+ if (vma->vm_flags & VM_LOCKED)
+ munlock_vma_pages_all(vma);
+ vma = vma->vm_next;
+ }
+ }
+ vma = mm->mmap;
lru_add_drain();
flush_cache_mm(mm);
tlb = tlb_gather_mmu(mm, 1);
diff --git a/mm/mremap.c b/mm/mremap.c
index 1a7743923c8c42c536d79ecb64f45457b2a3f994..58a2908f42f500002e49adc218adbca0e8602c26 100644
--- a/mm/mremap.c
+++ b/mm/mremap.c
@@ -24,6 +24,8 @@
#include <asm/cacheflush.h>
#include <asm/tlbflush.h>
+#include "internal.h"
+
static pmd_t *get_old_pmd(struct mm_struct *mm, unsigned long addr)
{
pgd_t *pgd;
@@ -238,8 +240,8 @@ static unsigned long move_vma(struct vm_area_struct *vma,
if (vm_flags & VM_LOCKED) {
mm->locked_vm += new_len >> PAGE_SHIFT;
if (new_len > old_len)
- make_pages_present(new_addr + old_len,
- new_addr + new_len);
+ mlock_vma_pages_range(new_vma, new_addr + old_len,
+ new_addr + new_len);
}
return new_addr;
@@ -379,7 +381,7 @@ unsigned long do_mremap(unsigned long addr,
vm_stat_account(mm, vma->vm_flags, vma->vm_file, pages);
if (vma->vm_flags & VM_LOCKED) {
mm->locked_vm += pages;
- make_pages_present(addr + old_len,
+ mlock_vma_pages_range(vma, addr + old_len,
addr + new_len);
}
ret = addr;
diff --git a/mm/truncate.c b/mm/truncate.c
index e83e4b114ef12b78c74480cd0ddaa6b4369d3b4c..1229211104f84beb0e05e5df891f1780d392e418 100644
--- a/mm/truncate.c
+++ b/mm/truncate.c
@@ -18,6 +18,7 @@
#include <linux/task_io_accounting_ops.h>
#include <linux/buffer_head.h> /* grr. try_to_release_page,
do_invalidatepage */
+#include "internal.h"
/**
@@ -103,6 +104,7 @@ truncate_complete_page(struct address_space *mapping, struct page *page)
cancel_dirty_page(page, PAGE_CACHE_SIZE);
+ clear_page_mlock(page);
remove_from_page_cache(page);
ClearPageMappedToDisk(page);
page_cache_release(page); /* pagecache ref */
@@ -127,6 +129,7 @@ invalidate_complete_page(struct address_space *mapping, struct page *page)
if (PagePrivate(page) && !try_to_release_page(page, 0))
return 0;
+ clear_page_mlock(page);
ret = remove_mapping(mapping, page);
return ret;
@@ -352,6 +355,7 @@ invalidate_complete_page2(struct address_space *mapping, struct page *page)
if (PageDirty(page))
goto failed;
+ clear_page_mlock(page);
BUG_ON(PagePrivate(page));
__remove_from_page_cache(page);
spin_unlock_irq(&mapping->tree_lock);