The patch titled
Subject: mm rmap: remove vma_address check for address inside vma
has been added to the -mm tree. Its filename is
mm-rmap-remove-vma_address-check-for-address-inside-vma.patch
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------------------------------------------------------
From: Michel Lespinasse <walken@xxxxxxxxxx>
Subject: mm rmap: remove vma_address check for address inside vma
In file and anon rmap, we use interval trees to find potentially relevant
vmas and then call vma_address() to find the virtual address the given
page might be found at in these vmas. vma_address() used to include a
check that the returned address falls within the limits of the vma, but
this check isn't necessary now that we always use interval trees in rmap:
the interval tree just doesn't return any vmas which this check would find
to be irrelevant. As a result, we can replace the use of -EFAULT error
code (which then needed to be checked in every call site) with a
VM_BUG_ON().
Signed-off-by: Michel Lespinasse <walken@xxxxxxxxxx>
Cc: Andrea Arcangeli <aarcange@xxxxxxxxxx>
Cc: Rik van Riel <riel@xxxxxxxxxx>
Cc: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Cc: Daniel Santos <daniel.santos@xxxxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/huge_memory.c | 4 ---
mm/rmap.c | 48 +++++++++++++++++++--------------------------
2 files changed, 21 insertions(+), 31 deletions(-)
diff -puN mm/huge_memory.c~mm-rmap-remove-vma_address-check-for-address-inside-vma mm/huge_memory.c
--- a/mm/huge_memory.c~mm-rmap-remove-vma_address-check-for-address-inside-vma
+++ a/mm/huge_memory.c
@@ -1386,8 +1386,6 @@ static void __split_huge_page(struct pag
struct vm_area_struct *vma = avc->vma;
unsigned long addr = vma_address(page, vma);
BUG_ON(is_vma_temporary_stack(vma));
- if (addr == -EFAULT)
- continue;
mapcount += __split_huge_page_splitting(page, vma, addr);
}
/*
@@ -1412,8 +1410,6 @@ static void __split_huge_page(struct pag
struct vm_area_struct *vma = avc->vma;
unsigned long addr = vma_address(page, vma);
BUG_ON(is_vma_temporary_stack(vma));
- if (addr == -EFAULT)
- continue;
mapcount2 += __split_huge_page_map(page, vma, addr);
}
if (mapcount != mapcount2)
diff -puN mm/rmap.c~mm-rmap-remove-vma_address-check-for-address-inside-vma mm/rmap.c
--- a/mm/rmap.c~mm-rmap-remove-vma_address-check-for-address-inside-vma
+++ a/mm/rmap.c
@@ -510,22 +510,26 @@ void page_unlock_anon_vma(struct anon_vm
/*
* At what user virtual address is page expected in @vma?
- * Returns virtual address or -EFAULT if page's index/offset is not
- * within the range mapped the @vma.
*/
-inline unsigned long
-vma_address(struct page *page, struct vm_area_struct *vma)
+static inline unsigned long
+__vma_address(struct page *page, struct vm_area_struct *vma)
{
pgoff_t pgoff = page->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT);
- unsigned long address;
if (unlikely(is_vm_hugetlb_page(vma)))
pgoff = page->index << huge_page_order(page_hstate(page));
- address = vma->vm_start + ((pgoff - vma->vm_pgoff) << PAGE_SHIFT);
- if (unlikely(address < vma->vm_start || address >= vma->vm_end)) {
- /* page should be within @vma mapping range */
- return -EFAULT;
- }
+
+ return vma->vm_start + ((pgoff - vma->vm_pgoff) << PAGE_SHIFT);
+}
+
+inline unsigned long
+vma_address(struct page *page, struct vm_area_struct *vma)
+{
+ unsigned long address = __vma_address(page, vma);
+
+ /* page should be within @vma mapping range */
+ VM_BUG_ON(address < vma->vm_start || address >= vma->vm_end);
+
return address;
}
@@ -535,6 +539,7 @@ vma_address(struct page *page, struct vm
*/
unsigned long page_address_in_vma(struct page *page, struct vm_area_struct *vma)
{
+ unsigned long address;
if (PageAnon(page)) {
struct anon_vma *page__anon_vma = page_anon_vma(page);
/*
@@ -550,7 +555,10 @@ unsigned long page_address_in_vma(struct
return -EFAULT;
} else
return -EFAULT;
- return vma_address(page, vma);
+ address = __vma_address(page, vma);
+ if (unlikely(address < vma->vm_start || address >= vma->vm_end))
+ return -EFAULT;
+ return address;
}
/*
@@ -624,8 +632,8 @@ int page_mapped_in_vma(struct page *page
pte_t *pte;
spinlock_t *ptl;
- address = vma_address(page, vma);
- if (address == -EFAULT) /* out of vma range */
+ address = __vma_address(page, vma);
+ if (unlikely(address < vma->vm_start || address >= vma->vm_end))
return 0;
pte = page_check_address(page, vma->vm_mm, address, &ptl, 1);
if (!pte) /* the page is not in this mm */
@@ -732,8 +740,6 @@ static int page_referenced_anon(struct p
anon_vma_interval_tree_foreach(avc, &anon_vma->rb_root, pgoff, pgoff) {
struct vm_area_struct *vma = avc->vma;
unsigned long address = vma_address(page, vma);
- if (address == -EFAULT)
- continue;
/*
* If we are reclaiming on behalf of a cgroup, skip
* counting on behalf of references from different
@@ -799,8 +805,6 @@ static int page_referenced_file(struct p
vma_interval_tree_foreach(vma, &mapping->i_mmap, pgoff, pgoff) {
unsigned long address = vma_address(page, vma);
- if (address == -EFAULT)
- continue;
/*
* If we are reclaiming on behalf of a cgroup, skip
* counting on behalf of references from different
@@ -904,8 +908,6 @@ static int page_mkclean_file(struct addr
vma_interval_tree_foreach(vma, &mapping->i_mmap, pgoff, pgoff) {
if (vma->vm_flags & VM_SHARED) {
unsigned long address = vma_address(page, vma);
- if (address == -EFAULT)
- continue;
ret += page_mkclean_one(page, vma, address);
}
}
@@ -1468,8 +1470,6 @@ static int try_to_unmap_anon(struct page
continue;
address = vma_address(page, vma);
- if (address == -EFAULT)
- continue;
ret = try_to_unmap_one(page, vma, address, flags);
if (ret != SWAP_AGAIN || !page_mapped(page))
break;
@@ -1508,8 +1508,6 @@ static int try_to_unmap_file(struct page
mutex_lock(&mapping->i_mmap_mutex);
vma_interval_tree_foreach(vma, &mapping->i_mmap, pgoff, pgoff) {
unsigned long address = vma_address(page, vma);
- if (address == -EFAULT)
- continue;
ret = try_to_unmap_one(page, vma, address, flags);
if (ret != SWAP_AGAIN || !page_mapped(page))
goto out;
@@ -1684,8 +1682,6 @@ static int rmap_walk_anon(struct page *p
anon_vma_interval_tree_foreach(avc, &anon_vma->rb_root, pgoff, pgoff) {
struct vm_area_struct *vma = avc->vma;
unsigned long address = vma_address(page, vma);
- if (address == -EFAULT)
- continue;
ret = rmap_one(page, vma, address, arg);
if (ret != SWAP_AGAIN)
break;
@@ -1707,8 +1703,6 @@ static int rmap_walk_file(struct page *p
mutex_lock(&mapping->i_mmap_mutex);
vma_interval_tree_foreach(vma, &mapping->i_mmap, pgoff, pgoff) {
unsigned long address = vma_address(page, vma);
- if (address == -EFAULT)
- continue;
ret = rmap_one(page, vma, address, arg);
if (ret != SWAP_AGAIN)
break;
_
Patches currently in -mm which might be from walken@xxxxxxxxxx are
linux-next.patch
mm-adjust-final-endif-position-in-mm-internalh.patch
mm-fix-potential-anon_vma-locking-issue-in-mprotect.patch
ipc-mqueue-remove-unnecessary-rb_init_node-calls.patch
rbtree-reference-documentation-rbtreetxt-for-usage-instructions.patch
rbtree-empty-nodes-have-no-color.patch
rbtree-empty-nodes-have-no-color-fix.patch
rbtree-fix-incorrect-rbtree-node-insertion-in-fs-proc-proc_sysctlc.patch
rbtree-move-some-implementation-details-from-rbtreeh-to-rbtreec.patch
rbtree-move-some-implementation-details-from-rbtreeh-to-rbtreec-fix.patch
rbtree-performance-and-correctness-test.patch
rbtree-performance-and-correctness-test-fix.patch
rbtree-break-out-of-rb_insert_color-loop-after-tree-rotation.patch
rbtree-adjust-root-color-in-rb_insert_color-only-when-necessary.patch
rbtree-low-level-optimizations-in-rb_insert_color.patch
rbtree-adjust-node-color-in-__rb_erase_color-only-when-necessary.patch
rbtree-adjust-root-color-in-rb_insert_color-only-when-necessary-fix.patch
rbtree-optimize-case-selection-logic-in-__rb_erase_color.patch
rbtree-low-level-optimizations-in-__rb_erase_color.patch
rbtree-coding-style-adjustments.patch
rbtree-optimize-fetching-of-sibling-node.patch
rbtree-test-fix-sparse-warning-about-64-bit-constant.patch
rbtree-add-__rb_change_child-helper-function.patch
rbtree-place-easiest-case-first-in-rb_erase.patch
rbtree-handle-1-child-recoloring-in-rb_erase-instead-of-rb_erase_color.patch
rbtree-low-level-optimizations-in-rb_erase.patch
rbtree-augmented-rbtree-test.patch
rbtree-faster-augmented-rbtree-manipulation.patch
rbtree-remove-prior-augmented-rbtree-implementation.patch
rbtree-add-rb_declare_callbacks-macro.patch
rbtree-add-prio-tree-and-interval-tree-tests.patch
mm-replace-vma-prio_tree-with-an-interval-tree.patch
kmemleak-use-rbtree-instead-of-prio-tree.patch
prio_tree-remove.patch
rbtree-move-augmented-rbtree-functionality-to-rbtree_augmentedh.patch
mm-interval-tree-updates.patch
mm-anon-rmap-remove-anon_vma_moveto_tail.patch
mm-anon-rmap-replace-same_anon_vma-linked-list-with-an-interval-tree.patch
mm-rmap-remove-vma_address-check-for-address-inside-vma.patch
mm-add-config_debug_vm_rb-build-option.patch
mm-avoid-taking-rmap-locks-in-move_ptes.patch
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