106 lines
3.2 KiB
Diff
106 lines
3.2 KiB
Diff
From: Dave Hansen <dave@linux.vnet.ibm.com>
|
|
Date: Tue, 29 May 2012 15:06:46 -0700
|
|
Subject: hugetlb: fix resv_map leak in error path
|
|
|
|
commit c50ac050811d6485616a193eb0f37bfbd191cc89 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>
|
|
---
|
|
mm/hugetlb.c | 28 ++++++++++++++++++++++------
|
|
1 file changed, 22 insertions(+), 6 deletions(-)
|
|
|
|
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
|
|
index 41a647d..285a81e 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)
|