From fed84c78527009d4f799a3ed9a566502fa026d82 Mon Sep 17 00:00:00 2001 From: Qian Cai Date: Fri, 28 Dec 2018 00:36:29 -0800 Subject: mm/memblock.c: skip kmemleak for kasan_init() 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 nested loops while KASAN is setting up full memory mappings, so let early kmemleak allocations skip those memblock_alloc_internal() calls came from kasan_init() given that those early KASAN memory mappings should not reference to other memory. Hence, no kmemleak false positives. kasan_init kasan_map_populate [1] kasan_pgd_populate [2] kasan_pud_populate [3] kasan_pmd_populate [4] kasan_pte_populate [5] kasan_alloc_zeroed_page memblock_alloc_try_nid memblock_alloc_internal kmemleak_alloc [1] for_each_memblock(memory, reg) [2] while (pgdp++, addr = next, addr != end) [3] while (pudp++, addr = next, addr != end && pud_none(READ_ONCE(*pudp))) [4] while (pmdp++, addr = next, addr != end && pmd_none(READ_ONCE(*pmdp))) [5] while (ptep++, addr = next, addr != end && pte_none(READ_ONCE(*ptep))) Link: http://lkml.kernel.org/r/1543442925-17794-1-git-send-email-cai@gmx.us Signed-off-by: Qian Cai Acked-by: Catalin Marinas Cc: Michal Hocko Cc: Mike Rapoport Cc: Alexander Potapenko Cc: Dmitry Vyukov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/arm64/mm/kasan_init.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/arm64') diff --git a/arch/arm64/mm/kasan_init.c b/arch/arm64/mm/kasan_init.c index 3e142add890b..4b55b15707a3 100644 --- a/arch/arm64/mm/kasan_init.c +++ b/arch/arm64/mm/kasan_init.c @@ -39,7 +39,7 @@ static phys_addr_t __init kasan_alloc_zeroed_page(int node) { void *p = memblock_alloc_try_nid(PAGE_SIZE, PAGE_SIZE, __pa(MAX_DMA_ADDRESS), - MEMBLOCK_ALLOC_ACCESSIBLE, node); + MEMBLOCK_ALLOC_KASAN, node); return __pa(p); } -- cgit v1.2.3