Date: Fri, 21 Sep 2012 09:19:58 -0700 From: Devin Teske <devin.teske@fisglobal.com> To: Jilles Tjoelker <jilles@stack.nl> Cc: svn-src-head@freebsd.org, svn-src-all@freebsd.org, Devin Teske <dteske@FreeBSD.org>, src-committers@freebsd.org Subject: Re: svn commit: r240770 - in head/usr.sbin/bsdconfig: . console mouse networking networking/share share startup startup/share timezone/share usermgmt/share Message-ID: <7D546F33-EECC-4940-BDC6-FA73F330882A@fisglobal.com> In-Reply-To: <20120921113654.GA7865@stack.nl> References: <201209210136.q8L1aKiF031991@svn.freebsd.org> <20120921113654.GA7865@stack.nl>
next in thread | previous in thread | raw e-mail | index | archive | help
On Sep 21, 2012, at 4:36 AM, Jilles Tjoelker wrote: > On Fri, Sep 21, 2012 at 01:36:20AM +0000, Devin Teske wrote: >> Author: dteske >> Date: Fri Sep 21 01:36:20 2012 >> New Revision: 240770 >> URL: http://svn.freebsd.org/changeset/base/240770 >=20 >> Log: >> Replace redirections to /dev/null with "close file-descriptor" syntax (= >&-). >=20 >> Reviewed by: adrian (co-mentor) >> Approved by: adrian (co-mentor) >=20 >> [snip] >=20 >> Modified: head/usr.sbin/bsdconfig/bsdconfig >> =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D >> --- head/usr.sbin/bsdconfig/bsdconfig Fri Sep 21 00:36:35 2012 (r240769) >> +++ head/usr.sbin/bsdconfig/bsdconfig Fri Sep 21 01:36:20 2012 (r240770) >> @@ -73,7 +73,7 @@ usage() >> # Determine the maximum width of terminal/console >> # >> local max_size max_width >> - max_size=3D$( stty size 2> /dev/null ) >> + max_size=3D$( stty size 2>&- ) >> : ${max_size:=3D"24 80"} >> max_width=3D"${max_size#*[$IFS]}" >> f_dprintf "max_width=3D[$max_width]" >> [snip] >=20 > This change is risky because it may cause error messages to be written > to unexpected files. The first file the utility opens will be fd 2, and > if something decides to write an error message to fd 2 it will try to > write to that file. >=20 > For this reason, the kernel will automatically open /dev/null if you > execute suid/sgid binaries with fd 0, 1 and/or 2 closed. >=20 > Particularly with fd 1 (>&-) there is another danger in that the output > may fail with [EBADF] rather than being silently discarded. This may > cause unexpected failures. >=20 > If the reason is that there may be no /dev/null, then you will have to > change the environment such that there will be a /dev/null. >=20 Jilles and I discussed in IRC and he showed me how I can make /dev/null ava= ilable in the embedded environment that this was needed for. I'm going to make another revision that reverses the changes in SVN r240770= (this change). Thanks Jilles! --=20 Devin _____________ The information contained in this message is proprietary and/or confidentia= l. If you are not the intended recipient, please: (i) delete the message an= d all copies; (ii) do not disclose, distribute or use the message in any ma= nner; and (iii) notify the sender immediately. In addition, please be aware= that any message addressed to our domain is subject to archiving and revie= w by persons other than the intended recipient. Thank you.
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?7D546F33-EECC-4940-BDC6-FA73F330882A>