The patch titled
Subject: mm: fix crashes from mbind() merging vmas
has been added to the -mm tree. Its filename is
mm-fix-crashes-from-mbind-merging-vmas.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/mm-fix-crashes-from-mbind-merging-vmas.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/mm-fix-crashes-from-mbind-merging-vmas.patch
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*** Remember to use Documentation/SubmitChecklist when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Hugh Dickins <hughd@xxxxxxxxxx>
Subject: mm: fix crashes from mbind() merging vmas
v2.6.34's 9d8cebd4bcd7 ("mm: fix mbind vma merge problem") introduced vma
merging to mbind(), but it should have also changed the convention of
passing start vma from queue_pages_range() (formerly check_range()) to
new_vma_page(): vma merging may have already freed that structure,
resulting in BUG at mm/mempolicy.c:1738 and probably worse crashes.
Fixes: 9d8cebd4bcd7 ("mm: fix mbind vma merge problem")
Reported-by: Naoya Horiguchi <n-horiguchi@xxxxxxxxxxxxx>
Tested-by: Naoya Horiguchi <n-horiguchi@xxxxxxxxxxxxx>
Signed-off-by: Hugh Dickins <hughd@xxxxxxxxxx>
Acked-by: Christoph Lameter <cl@xxxxxxxxx>
Cc: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx>
Cc: Minchan Kim <minchan.kim@xxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx> [2.6.34+]
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/mempolicy.c | 46 ++++++++++++++++++++--------------------------
1 file changed, 20 insertions(+), 26 deletions(-)
diff -puN mm/mempolicy.c~mm-fix-crashes-from-mbind-merging-vmas mm/mempolicy.c
--- a/mm/mempolicy.c~mm-fix-crashes-from-mbind-merging-vmas
+++ a/mm/mempolicy.c
@@ -656,19 +656,18 @@ static unsigned long change_prot_numa(st
* @nodes and @flags,) it's isolated and queued to the pagelist which is
* passed via @private.)
*/
-static struct vm_area_struct *
+static int
queue_pages_range(struct mm_struct *mm, unsigned long start, unsigned long end,
const nodemask_t *nodes, unsigned long flags, void *private)
{
- int err;
- struct vm_area_struct *first, *vma, *prev;
-
+ int err = 0;
+ struct vm_area_struct *vma, *prev;
- first = find_vma(mm, start);
- if (!first)
- return ERR_PTR(-EFAULT);
+ vma = find_vma(mm, start);
+ if (!vma)
+ return -EFAULT;
prev = NULL;
- for (vma = first; vma && vma->vm_start < end; vma = vma->vm_next) {
+ for (; vma && vma->vm_start < end; vma = vma->vm_next) {
unsigned long endvma = vma->vm_end;
if (endvma > end)
@@ -678,9 +677,9 @@ queue_pages_range(struct mm_struct *mm,
if (!(flags & MPOL_MF_DISCONTIG_OK)) {
if (!vma->vm_next && vma->vm_end < end)
- return ERR_PTR(-EFAULT);
+ return -EFAULT;
if (prev && prev->vm_end < vma->vm_start)
- return ERR_PTR(-EFAULT);
+ return -EFAULT;
}
if (flags & MPOL_MF_LAZY) {
@@ -694,15 +693,13 @@ queue_pages_range(struct mm_struct *mm,
err = queue_pages_pgd_range(vma, start, endvma, nodes,
flags, private);
- if (err) {
- first = ERR_PTR(err);
+ if (err)
break;
- }
}
next:
prev = vma;
}
- return first;
+ return err;
}
/*
@@ -1156,16 +1153,17 @@ out:
/*
* Allocate a new page for page migration based on vma policy.
- * Start assuming that page is mapped by vma pointed to by @private.
+ * Start by assuming the page is mapped by the same vma as contains @start.
* Search forward from there, if not. N.B., this assumes that the
* list of pages handed to migrate_pages()--which is how we get here--
* is in virtual address order.
*/
-static struct page *new_vma_page(struct page *page, unsigned long private, int **x)
+static struct page *new_page(struct page *page, unsigned long start, int **x)
{
- struct vm_area_struct *vma = (struct vm_area_struct *)private;
+ struct vm_area_struct *vma;
unsigned long uninitialized_var(address);
+ vma = find_vma(current->mm, start);
while (vma) {
address = page_address_in_vma(page, vma);
if (address != -EFAULT)
@@ -1195,7 +1193,7 @@ int do_migrate_pages(struct mm_struct *m
return -ENOSYS;
}
-static struct page *new_vma_page(struct page *page, unsigned long private, int **x)
+static struct page *new_page(struct page *page, unsigned long start, int **x)
{
return NULL;
}
@@ -1205,7 +1203,6 @@ static long do_mbind(unsigned long start
unsigned short mode, unsigned short mode_flags,
nodemask_t *nmask, unsigned long flags)
{
- struct vm_area_struct *vma;
struct mm_struct *mm = current->mm;
struct mempolicy *new;
unsigned long end;
@@ -1271,11 +1268,9 @@ static long do_mbind(unsigned long start
if (err)
goto mpol_out;
- vma = queue_pages_range(mm, start, end, nmask,
+ err = queue_pages_range(mm, start, end, nmask,
flags | MPOL_MF_INVERT, &pagelist);
-
- err = PTR_ERR(vma); /* maybe ... */
- if (!IS_ERR(vma))
+ if (!err)
err = mbind_range(mm, start, end, new);
if (!err) {
@@ -1283,9 +1278,8 @@ static long do_mbind(unsigned long start
if (!list_empty(&pagelist)) {
WARN_ON_ONCE(flags & MPOL_MF_LAZY);
- nr_failed = migrate_pages(&pagelist, new_vma_page,
- NULL, (unsigned long)vma,
- MIGRATE_SYNC, MR_MEMPOLICY_MBIND);
+ nr_failed = migrate_pages(&pagelist, new_page, NULL,
+ start, MIGRATE_SYNC, MR_MEMPOLICY_MBIND);
if (nr_failed)
putback_movable_pages(&pagelist);
}
_
Patches currently in -mm which might be from hughd@xxxxxxxxxx are
tmpfs-zero_range-and-collapse_range-not-currently-supported.patch
hugetlb-fix-copy_hugetlb_page_range-to-handle-migration-hwpoisoned-entry.patch
mm-thp-fix-debug_pagealloc-oops-in-copy_page_rep.patch
mm-thp-fix-debug_pagealloc-oops-in-copy_page_rep-checkpatch-fixes.patch
mm-let-mm_find_pmd-fix-buggy-race-with-thp-fault.patch
shmem-fix-faulting-into-a-hole-while-its-punched.patch
shmem-fix-faulting-into-a-hole-while-its-punched-checkpatch-fixes.patch
mm-fix-crashes-from-mbind-merging-vmas.patch
mm-memoryc-use-entry-=-access_oncepte-in-handle_pte_fault.patch
mm-memcontrol-fold-mem_cgroup_do_charge.patch
mm-memcontrol-rearrange-charging-fast-path.patch
mm-memcontrol-reclaim-at-least-once-for-__gfp_noretry.patch
mm-huge_memory-use-gfp_transhuge-when-charging-huge-pages.patch
mm-memcontrol-retry-reclaim-for-oom-disabled-and-__gfp_nofail-charges.patch
mm-memcontrol-remove-explicit-oom-parameter-in-charge-path.patch
mm-memcontrol-simplify-move-precharge-function.patch
mm-memcontrol-catch-root-bypass-in-move-precharge.patch
mm-memcontrol-use-root_mem_cgroup-res_counter.patch
mm-memcontrol-remove-ordering-between-pc-mem_cgroup-and-pagecgroupused.patch
mm-memcontrol-do-not-acquire-page_cgroup-lock-for-kmem-pages.patch
mm-memcontrol-rewrite-charge-api.patch
mm-memcontrol-rewrite-uncharge-api.patch
list-use-argument-hlist_add_after-names-from-rcu-variant.patch
list-fix-order-of-arguments-for-hlist_add_after_rcu.patch
klist-use-same-naming-scheme-as-hlist-for-klist_add_after.patch
mm-replace-remap_file_pages-syscall-with-emulation-fix-3.patch
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