mbox series

[0/4] bitmap: fix conversion from/to fix-sized arrays

Message ID 20220420222530.910125-1-yury.norov@gmail.com (mailing list archive)
Headers show
Series bitmap: fix conversion from/to fix-sized arrays | expand

Message

Yury Norov April 20, 2022, 10:25 p.m. UTC 
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 already have bitmap_{from,to}_arr32().
In recent discussion it was spotted that we also need 64-bit
analogue of it:
https://lore.kernel.org/all/YiCWNdWd+AsLbDkp@smile.fi.intel.com/T/#m754da92acb0003e12b99293d07ddcd46dbe04ada

This series takes care of it.

Yury Norov (4):
  lib/bitmap: extend comment for bitmap_(from,to)_arr32()
  lib: add 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                                  | 47 +++++++++++++++++++
 5 files changed, 77 insertions(+), 15 deletions(-)