Messages in this thread | | | Date | Tue, 4 Aug 2020 15:25:26 +0200 | From | Michal Hocko <> | Subject | Re: [PATCH 1/2][next] mm: memcontrol: Use flex_array_size() helper in memcpy() |
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On Fri 31-07-20 12:12:53, Gustavo A. R. Silva wrote: > Make use of the flex_array_size() helper to calculate the size of a > flexible array member within an enclosing structure. > > This helper offers defense-in-depth against potential integer > overflows, while at the same time makes it explicitly clear that > we are dealing with a flexible array member. > > Also, remove unnecessary braces.
I was not aware of this helper. The code looks slightly better.
> Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Acked-by: Michal Hocko <mhocko@suse.com> > --- > mm/memcontrol.c | 7 +++---- > 1 file changed, 3 insertions(+), 4 deletions(-) > > diff --git a/mm/memcontrol.c b/mm/memcontrol.c > index e84c2b5596f2..bd7f972ceea4 100644 > --- a/mm/memcontrol.c > +++ b/mm/memcontrol.c > @@ -4246,10 +4246,9 @@ static int __mem_cgroup_usage_register_event(struct mem_cgroup *memcg, > new->size = size; > > /* Copy thresholds (if any) to new array */ > - if (thresholds->primary) { > - memcpy(new->entries, thresholds->primary->entries, (size - 1) * > - sizeof(struct mem_cgroup_threshold)); > - } > + if (thresholds->primary) > + memcpy(new->entries, thresholds->primary->entries, > + flex_array_size(new, entries, size - 1)); > > /* Add new threshold */ > new->entries[size - 1].eventfd = eventfd; > -- > 2.27.0
-- Michal Hocko SUSE Labs
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