Commit 2d6261583be0 ("lib: rework bitmap_parse()") does not take into account order of halfwords on 64-bit big endian architectures. As result (at least) Receive Packet Steering, IRQ affinity masks and runtime kernel test "test_bitmap" get broken on s390.
Fixes: 2d6261583be0 ("lib: rework bitmap_parse()") Cc: sta...@vger.kernel.org Cc: Andrew Morton <a...@linux-foundation.org> Cc: Yury Norov <yury.no...@gmail.com> Cc: Andy Shevchenko <andriy.shevche...@linux.intel.com> Cc: Amritha Nambiar <amritha.namb...@intel.com> Cc: Arnaldo Carvalho de Melo <a...@redhat.com> Cc: Chris Wilson <ch...@chris-wilson.co.uk> Cc: Kees Cook <keesc...@chromium.org> Cc: Matthew Wilcox <wi...@infradead.org> Cc: Miklos Szeredi <mszer...@redhat.com> Cc: Rasmus Villemoes <li...@rasmusvillemoes.dk> Cc: Steffen Klassert <steffen.klass...@secunet.com> Cc: "Tobin C . Harding" <to...@kernel.org> Cc: Vineet Gupta <vineet.gup...@synopsys.com> Cc: Will Deacon <will.dea...@arm.com> Cc: Willem de Bruijn <will...@google.com> Signed-off-by: Alexander Gordeev <agord...@linux.ibm.com> --- lib/bitmap.c | 20 ++++++++++++++++++-- 1 file changed, 18 insertions(+), 2 deletions(-) diff --git a/lib/bitmap.c b/lib/bitmap.c index 89260aa342d6..a725e4612984 100644 --- a/lib/bitmap.c +++ b/lib/bitmap.c @@ -717,6 +717,19 @@ static const char *bitmap_get_x32_reverse(const char *start, return end; } +#if defined(__BIG_ENDIAN) && defined(CONFIG_64BIT) +static void save_x32_chunk(unsigned long *maskp, u32 chunk, int chunk_idx) +{ + maskp += (chunk_idx / 2); + ((u32 *)maskp)[(chunk_idx & 1) ^ 1] = chunk; +} +#else +static void save_x32_chunk(unsigned long *maskp, u32 chunk, int chunk_idx) +{ + ((u32 *)maskp)[chunk_idx] = chunk; +} +#endif + /** * bitmap_parse - convert an ASCII hex string into a bitmap. * @start: pointer to buffer containing string. @@ -738,7 +751,8 @@ int bitmap_parse(const char *start, unsigned int buflen, { const char *end = strnchrnul(start, buflen, '\n') - 1; int chunks = BITS_TO_U32(nmaskbits); - u32 *bitmap = (u32 *)maskp; + int chunk_idx = 0; + u32 chunk; int unset_bit; while (1) { @@ -749,9 +763,11 @@ int bitmap_parse(const char *start, unsigned int buflen, if (!chunks--) return -EOVERFLOW; - end = bitmap_get_x32_reverse(start, end, bitmap++); + end = bitmap_get_x32_reverse(start, end, &chunk); if (IS_ERR(end)) return PTR_ERR(end); + + save_x32_chunk(maskp, chunk, chunk_idx++); } unset_bit = (BITS_TO_U32(nmaskbits) - chunks) * 32; -- 2.23.0