From mboxrd@z Thu Jan  1 00:00:00 1970
X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on inbox.vuxu.org
X-Spam-Level: 
X-Spam-Status: No, score=-3.3 required=5.0 tests=MAILING_LIST_MULTI,
	RCVD_IN_DNSWL_MED,RCVD_IN_MSPIKE_H3,RCVD_IN_MSPIKE_WL autolearn=ham
	autolearn_force=no version=3.4.4
Received: (qmail 25588 invoked from network); 24 Jul 2021 01:40:37 -0000
Received: from mother.openwall.net (195.42.179.200)
  by inbox.vuxu.org with ESMTPUTF8; 24 Jul 2021 01:40:37 -0000
Received: (qmail 3904 invoked by uid 550); 24 Jul 2021 01:40:35 -0000
Mailing-List: contact musl-help@lists.openwall.com; run by ezmlm
Precedence: bulk
List-Post: <mailto:musl@lists.openwall.com>
List-Help: <mailto:musl-help@lists.openwall.com>
List-Unsubscribe: <mailto:musl-unsubscribe@lists.openwall.com>
List-Subscribe: <mailto:musl-subscribe@lists.openwall.com>
List-ID: <musl.lists.openwall.com>
Reply-To: musl@lists.openwall.com
Received: (qmail 3883 invoked from network); 24 Jul 2021 01:40:34 -0000
Date: Fri, 23 Jul 2021 21:40:22 -0400
From: Rich Felker <dalias@libc.org>
To: Yuri Kanivetsky <yuri.kanivetsky@gmail.com>
Cc: musl@lists.openwall.com
Message-ID: <20210724014021.GM13220@brightrain.aerifal.cx>
References: <CAMhVC3ZwQdPK76Nw2QCc787wD=CN4XixJ1J6YbidhPBt5T-v6g@mail.gmail.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <CAMhVC3ZwQdPK76Nw2QCc787wD=CN4XixJ1J6YbidhPBt5T-v6g@mail.gmail.com>
User-Agent: Mutt/1.5.21 (2010-09-15)
Subject: Re: [musl] faccessat() always return EPERM

On Sat, Jul 24, 2021 at 04:16:25AM +0300, Yuri Kanivetsky wrote:
> Hi,
> 
> I'm not sure that it has something to do with musl. But experienced in
> a Alpine Linux docker container (ruby:2.6-alpine3.14) on Debian 9 or
> 10. I can't reproduce it with Alpine Linux 3.13 (container) or Debian
> 8 (host).
> 
> For example, the following program outputs -1:
> 
> #include <stdio.h>
> #include <fcntl.h>
> #include <unistd.h>
> 
> int main()
> {
>     int r;
>     r = faccessat(AT_FDCWD, "/", R_OK, AT_EACCESS);
>     printf("%i", r);
>     return 0;
> }
> 
> I believe whatever is passed as the second parameter, it would return -1.
> 
> As a result at least irb and bundler doesn't work. Is this some sort
> of binary incompatibility with Linux kernel?

No, it's almost surely Docker blocking the operation with the wrong
error code (EPERM):

https://github.com/opencontainers/runc/issues/2151

I'm not sure what the status on getting fix deployed is. It might go
away if the host running Docker can upgrade.

Rich