Kees Cook <keesc...@chromium.org> writes: > On Thu, Nov 17, 2016 at 2:53 AM, Michael Ellerman <m...@ellerman.id.au> wrote: >> kbuild test robot <l...@intel.com> writes: >>> [auto build test ERROR on char-misc/char-misc-testing] >>> [also build test ERROR on v4.9-rc5] >>> [cannot apply to next-20161115] >>> [if your patch is applied to the wrong git tree, please drop us a note to >>> help improve the system] >>> >>> url: >>> https://github.com/0day-ci/linux/commits/Michael-Ellerman/lkdtm-Add-tests-for-LIST_POISON-and-ZERO_SIZE_PTR/20161115-235441 >>> config: i386-randconfig-i0-201646 (attached as .config) >>> compiler: gcc-4.8 (Debian 4.8.4-1) 4.8.4 >>> reproduce: >>> # save the attached .config to linux build tree >>> make ARCH=i386 >>> >>> All errors (new ones prefixed by >>): >>> >>>>> ERROR: "mmap_min_addr" [drivers/misc/lkdtm.ko] undefined! >> >> I couldn't see what was causing this, but of course it's just that >> mmap_min_addr is not exported, and in that config LKDTM is a module. >> >> I always build it in which is why I didn't notice. >> >> I'm not sure we want to EXPORT_SYMBOL mmap_min_addr just for this test >> do we? I could change the test to use mmap_min_addr if LKDTM is >> built-in, and otherwise just map at zero. Dunno. > > Because of lkdtm's moduleness, I've had to put a lot of weird stuff > into EXPORT_SYMBOL_GPL(). mmap_min_addr is more sensitive than most, > though. How about just hard-coding it as 64k instead of using > mmap_min_addr?
We can just use CONFIG_DEFAULT_MMAP_MIN_ADDR, which should work unless someone's actually changed the value at runtime. Will test. I'd rather that than 64K hard-coded, as I'm thinking of increasing the minimum on ppc64. cheers
