linux-ext4 - [kj] is_power_of

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>] [day] [month] [year] [list]

Date:	Mon, 13 Aug 2007 18:27:02 +0530
From:	vignesh babu <vignesh.babu@...ro.com>
To:	sct@...hat.com, akpm@...ux-foundation.org, adilger@...sterfs.com
Cc:	linux-ext4@...r.kernel.org,
	Kernel Janitors List <kernel-janitors@...ts.osdl.org>
Subject: [kj] is_power_of_2 in ext

Replacing n & (n - 1) for power of 2 check by is_power_of_2(n)

Signed-off-by: vignesh babu <vignesh.babu@...ro.com>
---
diff --git a/fs/ext2/super.c b/fs/ext2/super.c
index 639a32c..f932c60 100644
--- a/fs/ext2/super.c
+++ b/fs/ext2/super.c
@@ -30,6 +30,7 @@
 #include <linux/vfs.h>
 #include <linux/seq_file.h>
 #include <linux/mount.h>
+#include <linux/log2.h>
 #include <asm/uaccess.h>
 #include "ext2.h"
 #include "xattr.h"
@@ -804,7 +805,7 @@ static int ext2_fill_super(struct super_block *sb, void *data, int silent)
 		sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
 		sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
 		if ((sbi->s_inode_size < EXT2_GOOD_OLD_INODE_SIZE) ||
-		    (sbi->s_inode_size & (sbi->s_inode_size - 1)) ||
+		    !is_power_of_2(sbi->s_inode_size) ||
 		    (sbi->s_inode_size > blocksize)) {
 			printk ("EXT2-fs: unsupported inode size: %d\n",
 				sbi->s_inode_size);
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 4550b83..0bfb88e 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -1667,7 +1667,7 @@ static int ext4_fill_super (struct super_block *sb, void *data, int silent)
 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT)) {
 		if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
 		    sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
-		    sbi->s_desc_size & (sbi->s_desc_size - 1)) {
+		    !is_power_of_2(sbi->s_desc_size)) {
 			printk(KERN_ERR
 			       "EXT4-fs: unsupported descriptor size %lu\n",
 			       sbi->s_desc_size);

-- 
Vignesh Babu BM 
_____________________________________________________________ 
"Why is it that every time I'm with you, makes me believe in magic?"

-
To unsubscribe from this list: send the line "unsubscribe linux-ext4" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html