On 08/07/20 at 05:12pm, Wei Yang wrote: > list_first_entry() may not return NULL even when the list is empty. > > Let's make sure the behavior by using list_first_entry_or_null(), > otherwise it would corrupt the list. > > Signed-off-by: Wei Yang <richard.weiy...@linux.alibaba.com> > --- > mm/hugetlb.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/mm/hugetlb.c b/mm/hugetlb.c > index 62ec74f6d03f..0a2f3851b828 100644 > --- a/mm/hugetlb.c > +++ b/mm/hugetlb.c > @@ -237,7 +237,8 @@ get_file_region_entry_from_cache(struct resv_map *resv, > long from, long to) > VM_BUG_ON(resv->region_cache_count <= 0);
We have had above line, is it possible to be NULL from list_first_entry? > > resv->region_cache_count--; > - nrg = list_first_entry(&resv->region_cache, struct file_region, link); > + nrg = list_first_entry_or_null(&resv->region_cache, > + struct file_region, link); > VM_BUG_ON(!nrg); > list_del(&nrg->link); > > -- > 2.20.1 (Apple Git-117) > >
