linux-ext4 - Re: [RFC PATCH 1/5] new helper: iov_iter

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

Date:	Tue, 17 Mar 2015 10:31:51 +0100
From:	David Sterba <dsterba@...e.cz>
To:	Al Viro <viro@...IV.linux.org.uk>
Cc:	Omar Sandoval <osandov@...ndov.com>, linux-fsdevel@...r.kernel.org,
	linux-btrfs@...r.kernel.org, ceph-devel@...r.kernel.org,
	linux-cifs@...r.kernel.org, osd-dev@...n-osd.org,
	linux-ext4@...r.kernel.org, linux-f2fs-devel@...ts.sourceforge.net,
	fuse-devel@...ts.sourceforge.net, cluster-devel@...hat.com,
	jfs-discussion@...ts.sourceforge.net, HPDD-discuss@...1.01.org,
	linux-nfs@...r.kernel.org, linux-nilfs@...r.kernel.org,
	ocfs2-devel@....oracle.com, reiserfs-devel@...r.kernel.org,
	v9fs-developer@...ts.sourceforge.net, xfs@....sgi.com,
	linux-kernel@...r.kernel.org, Chris Mason <clm@...com>,
	Josef Bacik <jbacik@...com>, David Sterba <dsterba@...e.cz>,
	Yan Zheng <zyan@...hat.com>, Sage Weil <sage@...hat.com>,
	Steve French <sfrench@...ba.org>,
	Boaz Harrosh <ooo@...ctrozaur.com>,
	Benny Halevy <bhalevy@...marydata.com>,
	Jan Kara <jack@...e.cz>, Theodore Ts'o <tytso@....edu>,
	Andreas Dilger <adilger.kernel@...ger.ca>,
	Jaegeuk Kim <jaegeuk@...nel.org>,
	Changman Lee <cm224.lee@...sung.com>,
	Miklos Szeredi <miklos@...redi.hu>,
	Steven Whitehouse <swhiteho@...hat.com>,
	Dave Kleikamp <shaggy@...nel.org>,
	Oleg Drokin <oleg.drokin@...el.com>,
	Trond Myklebust <trond.myklebust@...marydata.com>,
	Anna Schumaker <anna.schumaker@...app.com>,
	Ryusuke Konishi <konishi.ryusuke@....ntt.co.jp>,
	Mark Fasheh <mfasheh@...e.com>,
	Joel Becker <jlbec@...lplan.org>,
	Eric Van Hensbergen <ericvh@...il.com>,
	Ron Minnich <rminnich@...dia.gov>,
	Latchesar Ionkov <lucho@...kov.net>,
	Dave Chinner <david@...morbit.com>
Subject: Re: [RFC PATCH 1/5] new helper: iov_iter_rw()

On Mon, Mar 16, 2015 at 05:36:05PM +0000, Al Viro wrote:
> On Mon, Mar 16, 2015 at 04:33:49AM -0700, Omar Sandoval wrote:
> > Get either READ or WRITE out of iter->type.
> 
> Umm...  
> 
> > + * Get one of READ or WRITE out of iter->type without any other flags OR'd in
> > + * with it.
> > + */
> > +static inline int iov_iter_rw(const struct iov_iter *i)
> > +{
> > +	return i->type & RW_MASK;
> > +}
> 
> TBH, I would turn that into a macro.  Reason: indirect includes.

Agreed, but the proposed define is rather cryptic and I was not able to
understand the meaning on the first glance.

> #define iov_iter_rw(i) ((0 ? (struct iov_iter *)0 : (i))->type & RW_MASK)

This worked for me, does not compile with anything else than
'struct iov_iter*' as i:

#define iov_iter_rw(i)	({			\
	struct iov_iter __iter = *(i);		\
	(i)->type & RW_MASK;			\
	})

The assignment is optimized out.
--
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