linux-kernel - Re: [PATCH] btrfs: Simplify offset calculation method for ctree.h

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 for Android: free password hash cracker in your pocket

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

Message-ID: <9bd6b5360912172039y432361fu243d0f05bf75b7b7@mail.gmail.com>
Date:	Fri, 18 Dec 2009 12:39:50 +0800
From:	sniper <s3c24xx@...il.com>
To:	Zhaolei <zhaolei@...fujitsu.com>
Cc:	"linux-btrfs@...r.kernel.org" <linux-btrfs@...r.kernel.org>,
	LKML <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] btrfs: Simplify offset calculation method for ctree.h

No, many pointers in btrfs function arguments are not pointing to an
absolute address, but relative to the start address of extent.

Take following function as example, argument inode_item is an offset
value to the beginning of leaf. So we can't reach its member with
&inode_item->xxx

>  static inline struct btrfs_timespec *
>  btrfs_inode_mtime(struct btrfs_inode_item *inode_item)
>  {
> -       unsigned long ptr = (unsigned long)inode_item;
> -       ptr += offsetof(struct btrfs_inode_item, mtime);
> -       return (struct btrfs_timespec *)ptr;
> +       return &inode_item->mtime;
>  }
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/