linux-kernel - [PATCH v2] libnvdimm, badrange: replace div_u64_rem with DIV_ROUND

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-ID: <194fed48-eaf3-065f-9571-7813ad35b098@huawei.com>
Date:   Sat, 26 Jun 2021 11:53:13 +0800
From:   Kemeng Shi <shikemeng@...wei.com>
To:     <dan.j.williams@...el.com>, <vishal.l.verma@...el.com>,
        <dave.jiang@...el.com>, <ira.weiny@...el.com>,
        <nvdimm@...ts.linux.dev>, <linux-kernel@...r.kernel.org>
Subject: [PATCH v2] libnvdimm, badrange: replace div_u64_rem with DIV_ROUND_UP

__add_badblock_range use div_u64_rem to round up end_sector and it
will introduces unnecessary rem define and costly '%' operation.
So clean it with DIV_ROUND_UP.

Signed-off-by: Kemeng Shi <shikemeng@...wei.com>
---
V1->V2:
-- fix that end_sector is assigned twice, sorry for that.

 drivers/nvdimm/badrange.c | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/drivers/nvdimm/badrange.c b/drivers/nvdimm/badrange.c
index aaf6e215a8c6..af622ae511aa 100644
--- a/drivers/nvdimm/badrange.c
+++ b/drivers/nvdimm/badrange.c
@@ -187,12 +187,9 @@ static void __add_badblock_range(struct badblocks *bb, u64 ns_offset, u64 len)
 	const unsigned int sector_size = 512;
 	sector_t start_sector, end_sector;
 	u64 num_sectors;
-	u32 rem;

 	start_sector = div_u64(ns_offset, sector_size);
-	end_sector = div_u64_rem(ns_offset + len, sector_size, &rem);
-	if (rem)
-		end_sector++;
+	end_sector = DIV_ROUND_UP(ns_offset + len, sector_size);
 	num_sectors = end_sector - start_sector;

 	if (unlikely(num_sectors > (u64)INT_MAX)) {
-- 
2.23.0

-- 
Best wishes
Kemeng Shi