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| author | Dave Hansen <dave@linux.vnet.ibm.com> | 2012-05-29 15:06:46 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-05-29 16:22:24 -0700 |
| commit | c50ac050811d6485616a193eb0f37bfbd191cc89 (patch) | |
| tree | e237c67e83182bad5744e17c867bb6bceb207544 /mm/hugetlb.c | |
| parent | 5c2b8a162b5f8616f709bf20d5ec88f709485522 (diff) | |
| download | linux-c50ac050811d6485616a193eb0f37bfbd191cc89.tar.bz2 | |
hugetlb: fix resv_map leak in error path
When called for anonymous (non-shared) mappings, hugetlb_reserve_pages()
does a resv_map_alloc(). It depends on code in hugetlbfs's
vm_ops->close() to release that allocation.
However, in the mmap() failure path, we do a plain unmap_region() without
the remove_vma() which actually calls vm_ops->close().
This is a decent fix. This leak could get reintroduced if new code (say,
after hugetlb_reserve_pages() in hugetlbfs_file_mmap()) decides to return
an error. But, I think it would have to unroll the reservation anyway.
Christoph's test case:
http://marc.info/?l=linux-mm&m=133728900729735
This patch applies to 3.4 and later. A version for earlier kernels is at
https://lkml.org/lkml/2012/5/22/418.
Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Reported-by: Christoph Lameter <cl@linux.com>
Tested-by: Christoph Lameter <cl@linux.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: <stable@vger.kernel.org> [2.6.32+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/hugetlb.c')
| -rw-r--r-- | mm/hugetlb.c | 28 |
1 files changed, 22 insertions, 6 deletions
diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 41a647dfb738..285a81e87ec8 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -2157,6 +2157,15 @@ static void hugetlb_vm_op_open(struct vm_area_struct *vma) kref_get(&reservations->refs); } +static void resv_map_put(struct vm_area_struct *vma) +{ + struct resv_map *reservations = vma_resv_map(vma); + + if (!reservations) + return; + kref_put(&reservations->refs, resv_map_release); +} + static void hugetlb_vm_op_close(struct vm_area_struct *vma) { struct hstate *h = hstate_vma(vma); @@ -2173,7 +2182,7 @@ static void hugetlb_vm_op_close(struct vm_area_struct *vma) reserve = (end - start) - region_count(&reservations->regions, start, end); - kref_put(&reservations->refs, resv_map_release); + resv_map_put(vma); if (reserve) { hugetlb_acct_memory(h, -reserve); @@ -2991,12 +3000,16 @@ int hugetlb_reserve_pages(struct inode *inode, set_vma_resv_flags(vma, HPAGE_RESV_OWNER); } - if (chg < 0) - return chg; + if (chg < 0) { + ret = chg; + goto out_err; + } /* There must be enough pages in the subpool for the mapping */ - if (hugepage_subpool_get_pages(spool, chg)) - return -ENOSPC; + if (hugepage_subpool_get_pages(spool, chg)) { + ret = -ENOSPC; + goto out_err; + } /* * Check enough hugepages are available for the reservation. @@ -3005,7 +3018,7 @@ int hugetlb_reserve_pages(struct inode *inode, ret = hugetlb_acct_memory(h, chg); if (ret < 0) { hugepage_subpool_put_pages(spool, chg); - return ret; + goto out_err; } /* @@ -3022,6 +3035,9 @@ int hugetlb_reserve_pages(struct inode *inode, if (!vma || vma->vm_flags & VM_MAYSHARE) region_add(&inode->i_mapping->private_list, from, to); return 0; +out_err: + resv_map_put(vma); + return ret; } void hugetlb_unreserve_pages(struct inode *inode, long offset, long freed) |