On Wed, Nov 28, 2018 at 12:40:33PM -0500, Qian Cai wrote: > Kmemleak does not play well with KASAN (tested on both HPE Apollo 70 and > Huawei TaiShan 2280 aarch64 servers). > > After calling start_kernel()->setup_arch()->kasan_init(), kmemleak early > log buffer went from something like 280 to 260000 which caused kmemleak > disabled and crash dump memory reservation failed. The multitude of > kmemleak_alloc() calls is from, > > for_each_memblock(memory, reg) x \ > while (pgdp++, addr = next, addr != end) x \ > while (pudp++, addr = next, addr != end && pud_none(READ_ONCE(*pudp))) \ > while (pmdp++, addr = next, addr != end && pmd_none(READ_ONCE(*pmdp))) \ > while (ptep++, addr = next, addr != end && pte_none(READ_ONCE(*ptep))) > > Signed-off-by: Qian Cai <cai@xxxxxx> Sorry, I didn't get the chance to investigate this further. Hopefully early next week. > diff --git a/mm/memblock.c b/mm/memblock.c > index 9a2d5ae..fd78e39 100644 > --- a/mm/memblock.c > +++ b/mm/memblock.c > @@ -1412,6 +1412,8 @@ static void * __init memblock_alloc_internal( > done: > ptr = phys_to_virt(alloc); > > +/* Skip kmemleak for kasan_init() due to high volume. */ > +#ifndef CONFIG_KASAN > /* > * The min_count is set to 0 so that bootmem allocated blocks > * are never reported as leaks. This is because many of these blocks > @@ -1419,6 +1421,7 @@ static void * __init memblock_alloc_internal( > * looked up by kmemleak. > */ > kmemleak_alloc(ptr, size, 0, 0); > +#endif This may render kmemleak unusable since it is not aware of the memblock allocations and it would trigger lots of false positives. -- Catalin
