Home Home > GIT Browse
summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorDave Hansen <dave@linux.vnet.ibm.com>2012-05-29 15:06:46 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2012-06-17 11:23:13 -0700
commit2209ffb965c6b17602aae5e637961e4f0f8a4162 (patch)
treefb51b504443c0abaa0d4508a35ac395a494c2432
parentc201beec4842674cd4773771931d25c9a5d45d66 (diff)
hugetlb: fix resv_map leak in error path
commit c50ac050811d6485616a193eb0f37bfbd191cc89 and 4523e1458566a0e8ecfaff90f380dd23acc44d27 upstream. 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> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--mm/hugetlb.c29
1 files changed, 23 insertions, 6 deletions
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 00b0abb75c94..05f8fd425f69 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -2060,6 +2060,15 @@ 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);
@@ -2075,7 +2084,7 @@ 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);
@@ -2877,12 +2886,16 @@ 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 filesystem quota for the mapping */
- if (hugetlb_get_quota(inode->i_mapping, chg))
- return -ENOSPC;
+ if (hugetlb_get_quota(inode->i_mapping, chg)) {
+ ret = -ENOSPC;
+ goto out_err;
+ }
/*
* Check enough hugepages are available for the reservation.
@@ -2891,7 +2904,7 @@ int hugetlb_reserve_pages(struct inode *inode,
ret = hugetlb_acct_memory(h, chg);
if (ret < 0) {
hugetlb_put_quota(inode->i_mapping, chg);
- return ret;
+ goto out_err;
}
/*
@@ -2908,6 +2921,10 @@ 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:
+ if (vma)
+ resv_map_put(vma);
+ return ret;
}
void hugetlb_unreserve_pages(struct inode *inode, long offset, long freed)