[PATCH v2 0/5] bitmap: fix conversion from/to fix-sized arrays

From: Yury Norov
Date: Thu Apr 28 2022 - 16:51:25 EST


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