From 81c4f4d924d5d009b5ed785a3e22b18d0f7b831f Mon Sep 17 00:00:00 2001 From: Alexander Gordeev Date: Wed, 10 Jun 2020 18:41:41 -0700 Subject: lib: fix bitmap_parse() on 64-bit big endian archs 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. [andriy.shevchenko@linux.intel.com: convert infinite while loop to a for loop] Link: http://lkml.kernel.org/r/20200609140535.87160-1-andriy.shevchenko@linux.intel.com Fixes: 2d6261583be0 ("lib: rework bitmap_parse()") Signed-off-by: Alexander Gordeev Signed-off-by: Andy Shevchenko Signed-off-by: Andrew Morton Reviewed-by: Andy Shevchenko Cc: Yury Norov Cc: Amritha Nambiar Cc: Arnaldo Carvalho de Melo Cc: Chris Wilson Cc: Kees Cook Cc: Matthew Wilcox Cc: Miklos Szeredi Cc: Rasmus Villemoes Cc: Steffen Klassert Cc: "Tobin C . Harding" Cc: Vineet Gupta Cc: Will Deacon Cc: Willem de Bruijn Cc: Link: http://lkml.kernel.org/r/1591634471-17647-1-git-send-email-agordeev@linux.ibm.com Signed-off-by: Linus Torvalds --- lib/bitmap.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) (limited to 'lib/bitmap.c') diff --git a/lib/bitmap.c b/lib/bitmap.c index 21a7640c5eed..0364452b1617 100644 --- a/lib/bitmap.c +++ b/lib/bitmap.c @@ -741,8 +741,9 @@ int bitmap_parse(const char *start, unsigned int buflen, int chunks = BITS_TO_U32(nmaskbits); u32 *bitmap = (u32 *)maskp; int unset_bit; + int chunk; - while (1) { + for (chunk = 0; ; chunk++) { end = bitmap_find_region_reverse(start, end); if (start > end) break; @@ -750,7 +751,11 @@ int bitmap_parse(const char *start, unsigned int buflen, if (!chunks--) return -EOVERFLOW; - end = bitmap_get_x32_reverse(start, end, bitmap++); +#if defined(CONFIG_64BIT) && defined(__BIG_ENDIAN) + end = bitmap_get_x32_reverse(start, end, &bitmap[chunk ^ 1]); +#else + end = bitmap_get_x32_reverse(start, end, &bitmap[chunk]); +#endif if (IS_ERR(end)) return PTR_ERR(end); } -- cgit v1.2.3