In the kernel codebase we have functions that call bitmap_copy() to convert bitmaps to and from fix-sized 32 or 64-bit arrays. It works well for LE architectures when size of long is equal to the size of fixed type. If the system is BE and/or size of long is not equal to the size of fixed type of the array, bitmap_copy() may produce wrong result either because of endianness issue, or because of out-of-bound access. To address this problem we have bitmap_{from,to}_arr32(). In recent discussion it was spotted that we also need 64-bit analogue: https://lore.kernel.org/all/YiCWNdWd+AsLbDkp@xxxxxxxxxxxxxxxxxx/T/#m754da92acb0003e12b99293d07ddcd46dbe04ada This series takes care of it. v1: https://lore.kernel.org/lkml/20220420222530.910125-3-yury.norov@xxxxxxxxx/T/ v2: - fix build warnings (patch 2) - add test for bitmap_{from,to}_arr64 Yury Norov (5): lib/bitmap: extend comment for bitmap_(from,to)_arr32() lib: add bitmap_{from,to}_arr64 lib/bitmap: add test for bitmap_{from,to}_arr64 KVM: s390: replace bitmap_copy with bitmap_{from,to}_arr64 where appropriate drm/amd/pm: use bitmap_{from,to}_arr32 where appropriate arch/s390/kvm/kvm-s390.c | 10 ++-- .../gpu/drm/amd/pm/swsmu/smu11/smu_v11_0.c | 2 +- .../gpu/drm/amd/pm/swsmu/smu13/smu_v13_0.c | 2 +- include/linux/bitmap.h | 31 +++++++++--- lib/bitmap.c | 48 +++++++++++++++++++ lib/test_bitmap.c | 25 ++++++++++ 6 files changed, 103 insertions(+), 15 deletions(-) -- 2.32.0