The patch titled
Subject: mm: bootmem: fix checking the bitmap when finally freeing bootmem
has been added to the -mm tree. Its filename is
mm-bootmem-fix-checking-the-bitmap-when-finally-freeing-bootmem.patch
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------------------------------------------------------
From: Gavin Shan <shangw@xxxxxxxxxxxxxxxxxx>
Subject: mm: bootmem: fix checking the bitmap when finally freeing bootmem
When bootmem releases an unaligned chunk of memory at the beginning of a
node to the page allocator, it iterates from that unaligned PFN but checks
an aligned word of the page bitmap. The checked bits do not correspond to
the PFNs and, as a result, reserved pages can be freed.
Properly shift the bitmap word so that the lowest bit corresponds to the
starting PFN before entering the freeing loop.
This bug has been around since 41546c1 ("bootmem: clean up
free_all_bootmem_core") (2.6.27) without known reports.
Signed-off-by: Gavin Shan <shangw@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Johannes Weiner <hannes@xxxxxxxxxxx>
Acked-by: Tejun Heo <tj@xxxxxxxxxx>
Acked-by: David S. Miller <davem@xxxxxxxxxxxxx>
Cc: Yinghai Lu <yinghai@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/bootmem.c | 1 +
1 file changed, 1 insertion(+)
diff -puN mm/bootmem.c~mm-bootmem-fix-checking-the-bitmap-when-finally-freeing-bootmem mm/bootmem.c
--- a/mm/bootmem.c~mm-bootmem-fix-checking-the-bitmap-when-finally-freeing-bootmem
+++ a/mm/bootmem.c
@@ -203,6 +203,7 @@ static unsigned long __init free_all_boo
} else {
unsigned long off = 0;
+ vec >>= start & (BITS_PER_LONG - 1);
while (vec && off < BITS_PER_LONG) {
if (vec & 1) {
page = pfn_to_page(start + off);
_
Subject: Subject: mm: bootmem: fix checking the bitmap when finally freeing bootmem
Patches currently in -mm which might be from shangw@xxxxxxxxxxxxxxxxxx are
mm-bootmem-fix-checking-the-bitmap-when-finally-freeing-bootmem.patch
mm-bootmem-rename-alloc_bootmem_core-to-alloc_bootmem_bdata.patch
mm-bootmem-split-out-goal-to-node-mapping-from-goal-dropping.patch
mm-bootmem-allocate-in-order-nodegoal-goal-node-anywhere.patch
mm-bootmem-unify-allocation-policy-of-non-panicking-node-allocations.patch
mm-nobootmem-panic-on-node-specific-allocation-failure.patch
mm-nobootmem-unify-allocation-policy-of-non-panicking-node-allocations.patch
mm-bootmem-pass-pgdat-instead-of-pgdat-bdata-down-the-stack.patch
mm-remove-sparsemem-allocation-details-from-the-bootmem-allocator.patch
--
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