From: Rob Landley <rob@landley.net>
To: Eric Paris <eparis@redhat.com>
Cc: linux-kernel@vger.kernel.org, libc-alpha@sourceware.org,
dwalsh@redhat.com, dmalcolm@redhat.com
Subject: Re: Friendlier EPERM - Request for input
Date: Sat, 12 Jan 2013 01:23:45 -0600 [thread overview]
Message-ID: <1357975425.32505.6@driftwood> (raw)
In-Reply-To: <1357747463.2593.28.camel@localhost> (from eparis@redhat.com on Wed Jan 9 10:04:23 2013)
On 01/09/2013 10:04:23 AM, Eric Paris wrote:
> Getting an EPERM/EACCES in userspace really kinda blows. As a user
> you
> don't have any idea why you got it. It could be SELinux, it could be
> rwx bits on the file, it could be a missing capability, it could be an
> ACL, it could be who knows what.
Adding SELinux, ACL, and capabilities to systems made them so much
easier to comprehend, didn't it? (My definition of "secure" includes
understanding what the system is doing. Crazy, I know.)
> We'd like to start figuring out the
> who knows what and hopefully find a way to expose that to userspace.
Obviously the response to having too many mechanisms doing the same
thing (badly) is to add a management interface. Piled higher and deeper.
> But maybe those great minds on the lists can help me think of ways to
> get Friendlier denials that I haven't thought of. Please. What are
> you
> thoughts, concerns, issues?
-EPERM was about file permissions. For SELinux and disability bits and
whatever they're calling OS/2 extended attributes this week you need
-EBUREAUCRACY.
Ken Thompson had the insight "files are just a flat sequence of bytes"
about the same time he invented subdirectories. Bruce Horn shoehorned
icon data into the Lisa filesystem metadata because they hadn't
implemented subdirectories yet so they couldn't collate files that way,
and apparently standard archive formats like "ELF" and "zip/jar" simply
didn't occur to him. (Yes really:
http://folklore.org/StoryView.py?project=Macintosh&story=The_Grand_Unified_Model_The_Finder.txt
).
Copying Bruce's reversion of Ken's insight because Microsoft blindly
copied Apple and now Windows doesn't know how to live without this
crutch really doesn't fill me with confidence. Oh well, too late now...
> -Eric
Rob
next prev parent reply other threads:[~2013-01-12 7:23 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-01-09 16:04 Friendlier EPERM - Request for input Eric Paris
2013-01-09 19:43 ` Eric Paris
2013-01-09 20:14 ` Casey Schaufler
2013-01-09 20:32 ` Eric Paris
2013-01-09 20:53 ` Casey Schaufler
2013-01-09 20:59 ` Jakub Jelinek
2013-01-09 21:09 ` Eric Paris
2013-01-09 22:17 ` Carlos O'Donell
2013-01-21 0:00 ` Eric W. Biederman
2013-01-21 0:59 ` Eric W. Biederman
2013-01-21 1:09 ` Mike Frysinger
2013-01-09 21:12 ` Casey Schaufler
2013-01-09 21:13 ` Eric Paris
2013-01-09 21:36 ` Casey Schaufler
2013-01-10 15:14 ` Tetsuo Handa
2013-01-10 16:34 ` Eric Paris
2013-01-11 13:00 ` Mimi Zohar
2013-01-12 5:08 ` Tetsuo Handa
2013-01-27 14:16 ` Rich Kulawiec
2013-01-12 7:23 ` Rob Landley [this message]
2013-01-12 20:27 ` Dr. David Alan Gilbert
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1357975425.32505.6@driftwood \
--to=rob@landley.net \
--cc=dmalcolm@redhat.com \
--cc=dwalsh@redhat.com \
--cc=eparis@redhat.com \
--cc=libc-alpha@sourceware.org \
--cc=linux-kernel@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox