2016-03-04 17:52 GMT+03:00 Alexander Potapenko <glider@xxxxxxxxxx>: > On Tue, Mar 1, 2016 at 12:57 PM, Andrey Ryabinin <ryabinin.a.a@xxxxxxxxx> wrote: >> >> >> On 02/29/2016 08:12 PM, Dmitry Vyukov wrote: >> >>>>> diff --git a/lib/Makefile b/lib/Makefile >>>>> index a7c26a4..10a4ae3 100644 >>>>> --- a/lib/Makefile >>>>> +++ b/lib/Makefile >>>>> @@ -167,6 +167,13 @@ obj-$(CONFIG_SG_SPLIT) += sg_split.o >>>>> obj-$(CONFIG_STMP_DEVICE) += stmp_device.o >>>>> obj-$(CONFIG_IRQ_POLL) += irq_poll.o >>>>> >>>>> +ifeq ($(CONFIG_KASAN),y) >>>>> +ifeq ($(CONFIG_SLAB),y) >>>> >>>> Just try to imagine that another subsystem wants to use stackdepot. How this gonna look like? >>>> >>>> We have Kconfig to describe dependencies. So, this should be under CONFIG_STACKDEPOT. >>>> So any user of this feature can just do 'select STACKDEPOT' in Kconfig. >>>> >>>>> + obj-y += stackdepot.o >>>>> + KASAN_SANITIZE_slub.o := n >> _stackdepot.o >> >> >>>> >>>>> + >>>>> + stack->hash = hash; >>>>> + stack->size = size; >>>>> + stack->handle.slabindex = depot_index; >>>>> + stack->handle.offset = depot_offset >> STACK_ALLOC_ALIGN; >>>>> + __memcpy(stack->entries, entries, size * sizeof(unsigned long)); >>>> >>>> s/__memcpy/memcpy/ >>> >>> memcpy should be instrumented by asan/tsan, and we would like to avoid >>> that instrumentation here. >> >> KASAN_SANITIZE_* := n already takes care about this. >> __memcpy() is a special thing solely for kasan internals and some assembly code. >> And it's not available generally. > As far as I can see, KASAN_SANITIZE_*:=n does not guarantee it. > It just removes KASAN flags from GCC command line, it does not > necessarily replace memcpy() calls with some kind of a > non-instrumented memcpy(). > With removed kasan cflags '__SANITIZE_ADDRESS__' is not defined, hence enable the following defines from arch/x86/include/asm/string_64.h: #if defined(CONFIG_KASAN) && !defined(__SANITIZE_ADDRESS__) /* * For files that not instrumented (e.g. mm/slub.c) we * should use not instrumented version of mem* functions. */ #undef memcpy #define memcpy(dst, src, len) __memcpy(dst, src, len) #define memmove(dst, src, len) __memmove(dst, src, len) #define memset(s, c, n) __memset(s, c, n) #endif -- 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>