| Message ID | 20220909092451.24883-14-linmiaohe@huawei.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | A few cleanup patches for mm | expand |
On 09.09.22 11:24, Miaohe Lin wrote: > The local variable buddy_pfn could be passed to buddy_merge_likely() > without initialization if the passed in order is MAX_ORDER - 1. This > looks buggy but buddy_pfn won't be used in this case as there's a > order >= MAX_ORDER - 2 check. Init buddy_pfn to 0 anyway to avoid > possible future misuse. > > Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> > --- > mm/page_alloc.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > index e1c7f98cff96..63ad25e86010 100644 > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -1113,7 +1113,7 @@ static inline void __free_one_page(struct page *page, > int migratetype, fpi_t fpi_flags) > { > struct capture_control *capc = task_capc(zone); > - unsigned long buddy_pfn; > + unsigned long buddy_pfn = 0; > unsigned long combined_pfn; > struct page *buddy; > bool to_tail; Yeah, why not. Reviewed-by: David Hildenbrand <david@redhat.com>
On 9/9/22 14:54, Miaohe Lin wrote: > The local variable buddy_pfn could be passed to buddy_merge_likely() > without initialization if the passed in order is MAX_ORDER - 1. This > looks buggy but buddy_pfn won't be used in this case as there's a > order >= MAX_ORDER - 2 check. Init buddy_pfn to 0 anyway to avoid > possible future misuse. > > Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com> > --- > mm/page_alloc.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > index e1c7f98cff96..63ad25e86010 100644 > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -1113,7 +1113,7 @@ static inline void __free_one_page(struct page *page, > int migratetype, fpi_t fpi_flags) > { > struct capture_control *capc = task_capc(zone); > - unsigned long buddy_pfn; > + unsigned long buddy_pfn = 0; > unsigned long combined_pfn; > struct page *buddy; > bool to_tail;
On Fri, Sep 09, 2022 at 05:24:48PM +0800, Miaohe Lin wrote: > The local variable buddy_pfn could be passed to buddy_merge_likely() > without initialization if the passed in order is MAX_ORDER - 1. This > looks buggy but buddy_pfn won't be used in this case as there's a > order >= MAX_ORDER - 2 check. Init buddy_pfn to 0 anyway to avoid > possible future misuse. > > Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> > --- > mm/page_alloc.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > index e1c7f98cff96..63ad25e86010 100644 > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -1113,7 +1113,7 @@ static inline void __free_one_page(struct page *page, > int migratetype, fpi_t fpi_flags) > { > struct capture_control *capc = task_capc(zone); > - unsigned long buddy_pfn; > + unsigned long buddy_pfn = 0; > unsigned long combined_pfn; > struct page *buddy; > bool to_tail; > -- > 2.23.0 >
diff --git a/mm/page_alloc.c b/mm/page_alloc.c index e1c7f98cff96..63ad25e86010 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -1113,7 +1113,7 @@ static inline void __free_one_page(struct page *page, int migratetype, fpi_t fpi_flags) { struct capture_control *capc = task_capc(zone); - unsigned long buddy_pfn; + unsigned long buddy_pfn = 0; unsigned long combined_pfn; struct page *buddy; bool to_tail;
The local variable buddy_pfn could be passed to buddy_merge_likely() without initialization if the passed in order is MAX_ORDER - 1. This looks buggy but buddy_pfn won't be used in this case as there's a order >= MAX_ORDER - 2 check. Init buddy_pfn to 0 anyway to avoid possible future misuse. Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> --- mm/page_alloc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)