On Wed, Jun 10, 2020 at 01:02:04PM +0200, Alexander Potapenko wrote: > On Wed, Jun 10, 2020 at 7:55 AM Dmitry Vyukov <dvyukov@xxxxxxxxxx> wrote: > > > > On Wed, Jun 10, 2020 at 7:22 AM Qian Cai <cai@xxxxxx> wrote: > > > > > > kernel_init_free_pages() will use memset() on s390 to clear all pages > > > from kmalloc_order() which will override KASAN redzones because a > > > redzone was setup from the end of the allocation size to the end of the > > > last page. Silence it by not reporting it there. An example of the > > > report is, > > > > Interesting. The reason why we did not hit it on x86_64 is because > > clear_page is implemented in asm (arch/x86/lib/clear_page_64.S) and > > thus is not instrumented. Arm64 probably does the same. However, on > > s390 clear_page is defined to memset. > > Can we define it to __memset() instead? > __memset() is supposed to be ignored by KASAN, e.g. KASAN runtime uses > it in the places where we don't care about bugs. I suppose that could work if s390 maintains perfer this way.
