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From: Mike Frysinger <vapier@gentoo.org>
To: libc-ports@sourceware.org
Cc: Roland McGrath <roland@redhat.com>,
	linasvepstas@gmail.com, Chris Metcalf <cmetcalf@tilera.com>,
	Arnd Bergmann <arnd@arndb.de>,
	GLIBC Devel <libc-alpha@sourceware.org>,
	linux-kernel@vger.kernel.org
Subject: Re: [BUG] Generic syscalls -- chmod vs. fchmodat
Date: Mon, 24 Jan 2011 16:32:22 -0500	[thread overview]
Message-ID: <201101241632.24425.vapier@gentoo.org> (raw)
In-Reply-To: <20110124210514.AB18918020B@magilla.sf.frob.com>

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On Monday, January 24, 2011 16:05:14 Roland McGrath wrote:
> POSIX says "A null pathname shall not be successfully resolved."  This
> applies to relative pathnames too, and a file name argument to an *at
> function using AT_FDCWD is a relative pathname.  So I think there is no
> situation at all in which the empty string should resolve to anything.
> It's generally in the domain of the kernel to enforce these kinds of rules,
> so I think that having the kernel fail with ENOENT for all empty-string
> cases is the right thing to do.

typically, Linux isnt hard pressed to enforce POSIX semantics.  that barrier 
is the realm of glibc.  the *at functions as implemented by Linux can provide 
neat semantics where you can open a directory, process a bunch of files via 
that fd, and then turn around and operate on the dir itself with NULL or "" 
paths.  plus, once Linux has shipped with a syscall behavior set, Linus really 
doesnt let people change it.  which means it's back on glibc's head to provide 
POSIX semantics to application.
-mike

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  reply	other threads:[~2011-01-24 21:32 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-01-24 19:57 Linas Vepstas
2011-01-24 21:05 ` Roland McGrath
2011-01-24 21:32   ` Mike Frysinger [this message]
2011-01-25 14:29 ` Arnd Bergmann
2011-01-25 17:45   ` Roland McGrath
2011-01-25 18:21     ` Arnd Bergmann
2011-01-25 18:34       ` Roland McGrath
2011-01-25 20:04         ` Arnd Bergmann
2011-01-25 18:52       ` Mike Frysinger
2011-01-25 19:56         ` Eric Blake
2011-01-25 20:31           ` Eric Blake
2011-01-25 21:32             ` Eric Blake
2011-01-25 22:10               ` Linas Vepstas
2011-02-10 18:12     ` Andries Brouwer
2011-02-10 18:17       ` Roland McGrath
2011-02-11  9:11       ` Andreas Schwab

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