• Qian Cai's avatar
    mm/memblock.c: skip kmemleak for kasan_init() · 051b746c
    Qian Cai authored
    [ Upstream commit fed84c78 ]
    
    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.usSigned-off-by: default avatarQian Cai <cai@gmx.us>
    Acked-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
    Cc: Michal Hocko <mhocko@suse.com>
    Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
    Cc: Alexander Potapenko <glider@google.com>
    Cc: Dmitry Vyukov <dvyukov@google.com>
    Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
    Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
    Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
    051b746c
memblock.h 18.8 KB