On Wed, 2019-09-04 at 14:49 +0200, Vlastimil Babka wrote: > On 9/4/19 8:51 AM, Walter Wu wrote: > > This patch is KASAN report adds the alloc/free stacks for page allocator > > in order to help programmer to see memory corruption caused by page. > > > > By default, KASAN doesn't record alloc/free stack for page allocator. > > It is difficult to fix up page use-after-free issue. > > > > This feature depends on page owner to record the last stack of pages. > > It is very helpful for solving the page use-after-free or out-of-bound. > > > > KASAN report will show the last stack of page, it may be: > > a) If page is in-use state, then it prints alloc stack. > > It is useful to fix up page out-of-bound issue. > > I expect this will conflict both in syntax and semantics with my series [1] that > adds the freeing stack to page_owner when used together with debug_pagealloc, > and it's now in mmotm. Glad others see the need as well :) Perhaps you could > review the series, see if it fulfils your usecase (AFAICS the series should be a > superset, by storing both stacks at once), and perhaps either make KASAN enable > debug_pagealloc, or turn KASAN into an alternative enabler of the functionality > there? > > Thanks, Vlastimil > > [1] https://lore.kernel.org/linux-mm/20190820131828.22684-1-vbabka@xxxxxxx/t/#u > Thanks your information. We focus on the smartphone, so it doesn't enable CONFIG_TRANSPARENT_HUGEPAGE, Is it invalid for our usecase? And It looks like something is different, because we only need last stack of page, so it can decrease memory overhead. I will try to enable debug_pagealloc(with your patch) and KASAN, then we see the result. Thanks. Walter
