On Tue, Aug 11, 2015 at 05:18:18AM +0300, Andrey Ryabinin wrote: > This patch adds arch specific code for kernel address sanitizer > (see Documentation/kasan.txt). > > 1/8 of kernel addresses reserved for shadow memory. There was no > big enough hole for this, so virtual addresses for shadow were > stolen from vmalloc area. > > At early boot stage the whole shadow region populated with just > one physical page (kasan_zero_page). Later, this page reused > as readonly zero shadow for some memory that KASan currently > don't track (vmalloc). > After mapping the physical memory, pages for shadow memory are > allocated and mapped. > > Functions like memset/memmove/memcpy do a lot of memory accesses. > If bad pointer passed to one of these function it is important > to catch this. Compiler's instrumentation cannot do this since > these functions are written in assembly. > KASan replaces memory functions with manually instrumented variants. > Original functions declared as weak symbols so strong definitions > in mm/kasan/kasan.c could replace them. Original functions have aliases > with '__' prefix in name, so we could call non-instrumented variant > if needed. > Some files built without kasan instrumentation (e.g. mm/slub.c). > Original mem* function replaced (via #define) with prefixed variants > to disable memory access checks for such files. > > Signed-off-by: Andrey Ryabinin <ryabinin.a.a@xxxxxxxxx> > Tested-by: Linus Walleij <linus.walleij@xxxxxxxxxx> Reviewed-by: Catalin Marinas <catalin.marinas@xxxxxxx> -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>