The patch titled
Subject: hugetlb: fix resv_map leak in error path
has been added to the -mm tree. Its filename is
hugetlb-fix-resv_map-leak-in-error-path.patch
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** 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: Dave Hansen <dave@xxxxxxxxxxxxxxxxxx>
Subject: 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
Signed-off-by: Dave Hansen <dave@xxxxxxxxxxxxxxxxxx>
Acked-by: Mel Gorman <mel@xxxxxxxxx>
Acked-by: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx>
Reported-by: Christoph Lameter <cl@xxxxxxxxx>
Tested-by: Christoph Lameter <cl@xxxxxxxxx>
Cc: Andrea Arcangeli <aarcange@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/hugetlb.c | 28 ++++++++++++++++++++++------
1 file changed, 22 insertions(+), 6 deletions(-)
diff -puN mm/hugetlb.c~hugetlb-fix-resv_map-leak-in-error-path mm/hugetlb.c
--- a/mm/hugetlb.c~hugetlb-fix-resv_map-leak-in-error-path
+++ a/mm/hugetlb.c
@@ -2223,6 +2223,15 @@ static void hugetlb_vm_op_open(struct vm
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);
@@ -2239,7 +2248,7 @@ static void hugetlb_vm_op_close(struct v
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);
@@ -3075,12 +3084,16 @@ int hugetlb_reserve_pages(struct 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.
@@ -3089,7 +3102,7 @@ int hugetlb_reserve_pages(struct inode *
ret = hugetlb_acct_memory(h, chg);
if (ret < 0) {
hugepage_subpool_put_pages(spool, chg);
- return ret;
+ goto out_err;
}
/*
@@ -3106,6 +3119,9 @@ int hugetlb_reserve_pages(struct 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)
_
Subject: Subject: hugetlb: fix resv_map leak in error path
Patches currently in -mm which might be from dave@xxxxxxxxxxxxxxxxxx are
hugetlb-fix-resv_map-leak-in-error-path.patch
--
To unsubscribe from this list: send the line "unsubscribe mm-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
