When charging to a hugetlb_cgroup fails, alloc_huge_page() returns
ERR_PTR(-ENOSPC) which will cause VM_FAULT_SIGBUS to be returned to the
page fault handler.
Instead, return the proper error code, ERR_PTR(-ENOMEM), so VM_FAULT_OOM
is handled correctly. This is consistent with failing mem cgroup charges
in the non-hugetlb fault path.
At the same time, restructure the return paths of alloc_huge_page() so it
is consistent.
Signed-off-by: David Rientjes <rientjes@xxxxxxxxxx>
---
mm/hugetlb.c | 18 ++++++++++++------
1 file changed, 12 insertions(+), 6 deletions(-)
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -2006,8 +2006,10 @@ struct page *alloc_huge_page(struct vm_area_struct *vma,
* code of zero indicates a reservation exists (no change).
*/
map_chg = gbl_chg = vma_needs_reservation(h, vma, addr);
- if (map_chg < 0)
- return ERR_PTR(-ENOMEM);
+ if (map_chg < 0) {
+ ret = -ENOMEM;
+ goto out;
+ }
/*
* Processes that did not create the mapping will have no
@@ -2019,8 +2021,8 @@ struct page *alloc_huge_page(struct vm_area_struct *vma,
if (map_chg || avoid_reserve) {
gbl_chg = hugepage_subpool_get_pages(spool, 1);
if (gbl_chg < 0) {
- vma_end_reservation(h, vma, addr);
- return ERR_PTR(-ENOSPC);
+ ret = -ENOSPC;
+ goto out_reservation;
}
/*
@@ -2049,8 +2051,10 @@ struct page *alloc_huge_page(struct vm_area_struct *vma,
if (!page) {
spin_unlock(&hugetlb_lock);
page = alloc_buddy_huge_page_with_mpol(h, vma, addr);
- if (!page)
+ if (!page) {
+ ret = -ENOSPC;
goto out_uncharge_cgroup;
+ }
if (!avoid_reserve && vma_has_reserves(vma, gbl_chg)) {
SetPagePrivate(page);
h->resv_huge_pages--;
@@ -2087,8 +2091,10 @@ struct page *alloc_huge_page(struct vm_area_struct *vma,
out_subpool_put:
if (map_chg || avoid_reserve)
hugepage_subpool_put_pages(spool, 1);
+out_reservation:
vma_end_reservation(h, vma, addr);
- return ERR_PTR(-ENOSPC);
+out:
+ return ERR_PTR(ret);
}
int alloc_bootmem_huge_page(struct hstate *h)
