Re: [RFC][PATCH 2/3] mm/page_poison.c: Enable PAGE_POISONING as a separate option

2016-01-26 Thread Laura Abbott
On 01/25/2016 10:39 PM, Jianyu Zhan wrote: On Tue, Jan 26, 2016 at 12:55 AM, Laura Abbott wrote: --- a/mm/debug-pagealloc.c +++ b/mm/debug-pagealloc.c @@ -8,11 +8,5 @@ void __kernel_map_pages(struct page *page, int numpages, int enable) { - if (!page_poisoning_enabled()) -

Re: [RFC][PATCH 2/3] mm/page_poison.c: Enable PAGE_POISONING as a separate option

2016-01-26 Thread Laura Abbott
On 01/25/2016 10:39 PM, Jianyu Zhan wrote: On Tue, Jan 26, 2016 at 12:55 AM, Laura Abbott wrote: --- a/mm/debug-pagealloc.c +++ b/mm/debug-pagealloc.c @@ -8,11 +8,5 @@ void __kernel_map_pages(struct page *page, int numpages, int enable) { - if

Re: [RFC][PATCH 2/3] mm/page_poison.c: Enable PAGE_POISONING as a separate option

2016-01-25 Thread Jianyu Zhan
On Tue, Jan 26, 2016 at 12:55 AM, Laura Abbott wrote: > --- a/mm/debug-pagealloc.c > +++ b/mm/debug-pagealloc.c > @@ -8,11 +8,5 @@ > > void __kernel_map_pages(struct page *page, int numpages, int enable) > { > - if (!page_poisoning_enabled()) > - return; > - > - if

[RFC][PATCH 2/3] mm/page_poison.c: Enable PAGE_POISONING as a separate option

2016-01-25 Thread Laura Abbott
Page poisoning is currently setup as a feature if architectures don't have architecture debug page_alloc to allow unmapping of pages. It has uses apart from that though. Clearing of the pages on free provides an increase in security as it helps to limit the risk of information leaks. Allow page

Re: [RFC][PATCH 2/3] mm/page_poison.c: Enable PAGE_POISONING as a separate option

2016-01-25 Thread Jianyu Zhan
On Tue, Jan 26, 2016 at 12:55 AM, Laura Abbott wrote: > --- a/mm/debug-pagealloc.c > +++ b/mm/debug-pagealloc.c > @@ -8,11 +8,5 @@ > > void __kernel_map_pages(struct page *page, int numpages, int enable) > { > - if (!page_poisoning_enabled()) > -

[RFC][PATCH 2/3] mm/page_poison.c: Enable PAGE_POISONING as a separate option

2016-01-25 Thread Laura Abbott
Page poisoning is currently setup as a feature if architectures don't have architecture debug page_alloc to allow unmapping of pages. It has uses apart from that though. Clearing of the pages on free provides an increase in security as it helps to limit the risk of information leaks. Allow page