From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:2220 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726660AbgFHKYW (ORCPT ); Mon, 8 Jun 2020 06:24:22 -0400 From: Alexander Gordeev Subject: [PATCH RESEND2] lib: fix bitmap_parse() on 64-bit big endian archs Date: Mon, 8 Jun 2020 12:23:49 +0200 Message-Id: <1591611829-23071-1-git-send-email-agordeev@linux.ibm.com> Sender: linux-s390-owner@vger.kernel.org List-ID: To: linux-kernel@vger.kernel.org Cc: linux-s390@vger.kernel.org, Alexander Gordeev , stable@vger.kernel.org, Andrew Morton , Yury Norov , Andy Shevchenko , Amritha Nambiar , Arnaldo Carvalho de Melo , Chris Wilson , Kees Cook , Matthew Wilcox , Miklos Szeredi , Rasmus Villemoes , Steffen Klassert , "Tobin C . Harding" , Vineet Gupta , Will Deacon , Willem de Bruijn 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: stable@vger.kernel.org Cc: Andrew Morton Cc: Yury Norov Cc: Andy Shevchenko 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 Signed-off-by: Alexander Gordeev --- 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