On Mon, Jun 8, 2020 at 8:47 PM Alexander Gordeev agordeev@linux.ibm.com wrote:
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.
LGTM (I would replace while loop, but it's style preference and one can consider worse than infinite loop)
Reviewed-by: Andy Shevchenko andy.shevchenko@gmail.com
Fixes: 2d6261583be0 ("lib: rework bitmap_parse()") Cc: stable@vger.kernel.org Cc: Andrew Morton akpm@linux-foundation.org Cc: Yury Norov yury.norov@gmail.com Cc: Andy Shevchenko andriy.shevchenko@linux.intel.com Cc: Amritha Nambiar amritha.nambiar@intel.com Cc: Arnaldo Carvalho de Melo acme@redhat.com Cc: Chris Wilson chris@chris-wilson.co.uk Cc: Kees Cook keescook@chromium.org Cc: Matthew Wilcox willy@infradead.org Cc: Miklos Szeredi mszeredi@redhat.com Cc: Rasmus Villemoes linux@rasmusvillemoes.dk Cc: Steffen Klassert steffen.klassert@secunet.com Cc: "Tobin C . Harding" tobin@kernel.org Cc: Vineet Gupta vineet.gupta1@synopsys.com Cc: Will Deacon will.deacon@arm.com Cc: Willem de Bruijn willemb@google.com Signed-off-by: Alexander Gordeev agordeev@linux.ibm.com
lib/bitmap.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/lib/bitmap.c b/lib/bitmap.c index 89260aa342d6..80d26b183248 100644 --- a/lib/bitmap.c +++ b/lib/bitmap.c @@ -739,6 +739,7 @@ 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 = 0; int unset_bit; while (1) {@@ -749,9 +750,14 @@ 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);
chunk++; } unset_bit = (BITS_TO_U32(nmaskbits) - chunks) * 32;-- 2.23.0