On Fri, Sep 26, 2014 at 10:01 AM, Sasha Levin <sasha.levin@xxxxxxxxxx> wrote: > On 09/24/2014 08:43 AM, Andrey Ryabinin wrote: >> Hi. >> >> This is a third iteration of kerenel address sanitizer (KASan). >> >> KASan is a runtime memory debugger designed to find use-after-free >> and out-of-bounds bugs. >> >> Currently KASAN supported only for x86_64 architecture and requires kernel >> to be build with SLUB allocator. >> KASAN uses compile-time instrumentation for checking every memory access, therefore you >> will need a fresh GCC >= v5.0.0. > > Hi Andrey, > > I tried this patchset, with the latest gcc, and I'm seeing the following: > > arch/x86/kernel/head.o: In function `_GLOBAL__sub_I_00099_0_reserve_ebda_region': > /home/sasha/linux-next/arch/x86/kernel/head.c:71: undefined reference to `__asan_init_v4' > init/built-in.o: In function `_GLOBAL__sub_I_00099_0___ksymtab_system_state': > /home/sasha/linux-next/init/main.c:1034: undefined reference to `__asan_init_v4' > init/built-in.o: In function `_GLOBAL__sub_I_00099_0_init_uts_ns': > /home/sasha/linux-next/init/version.c:50: undefined reference to `__asan_init_v4' > init/built-in.o: In function `_GLOBAL__sub_I_00099_0_root_mountflags': > /home/sasha/linux-next/init/do_mounts.c:638: undefined reference to `__asan_init_v4' > init/built-in.o: In function `_GLOBAL__sub_I_00099_0_rd_prompt': > /home/sasha/linux-next/init/do_mounts_rd.c:361: undefined reference to `__asan_init_v4' > init/built-in.o:/home/sasha/linux-next/init/do_mounts_md.c:312: more undefined references to `__asan_init_v4' follow > > > What am I missing? Emission of __asan_init_vx needs to be disabled when -fsanitize=kernel-address. Our kernel does not boot with them at all. It probably hits some limit for something that can be increased. But I don't want to investigate what that limit is, as __asan_init is not needed for kasan at all. -- 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>