From owner-freebsd-bugs@freebsd.org Tue Jun 14 22:07:12 2016 Return-Path: Delivered-To: freebsd-bugs@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 92F1EB727DA for ; Tue, 14 Jun 2016 22:07:12 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from kenobi.freebsd.org (kenobi.freebsd.org [IPv6:2001:1900:2254:206a::16:76]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 6992E299A for ; Tue, 14 Jun 2016 22:07:12 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from bugs.freebsd.org ([127.0.1.118]) by kenobi.freebsd.org (8.15.2/8.15.2) with ESMTP id u5EM7Cf1083996 for ; Tue, 14 Jun 2016 22:07:12 GMT (envelope-from bugzilla-noreply@freebsd.org) From: bugzilla-noreply@freebsd.org To: freebsd-bugs@FreeBSD.org Subject: [Bug 210288] File descriptors created by pipe are both read/write Date: Tue, 14 Jun 2016 22:07:12 +0000 X-Bugzilla-Reason: AssignedTo X-Bugzilla-Type: new X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: Base System X-Bugzilla-Component: kern X-Bugzilla-Version: 11.0-CURRENT X-Bugzilla-Keywords: X-Bugzilla-Severity: Affects Only Me X-Bugzilla-Who: kwilliams@qnx.com X-Bugzilla-Status: New X-Bugzilla-Resolution: X-Bugzilla-Priority: --- X-Bugzilla-Assigned-To: freebsd-bugs@FreeBSD.org X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: bug_id short_desc product version rep_platform op_sys bug_status bug_severity priority component assigned_to reporter attachments.created Message-ID: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: https://bugs.freebsd.org/bugzilla/ Auto-Submitted: auto-generated MIME-Version: 1.0 X-BeenThere: freebsd-bugs@freebsd.org X-Mailman-Version: 2.1.22 Precedence: list List-Id: Bug reports List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 14 Jun 2016 22:07:12 -0000 https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D210288 Bug ID: 210288 Summary: File descriptors created by pipe are both read/write Product: Base System Version: 11.0-CURRENT Hardware: Any OS: Any Status: New Severity: Affects Only Me Priority: --- Component: kern Assignee: freebsd-bugs@FreeBSD.org Reporter: kwilliams@qnx.com Created attachment 171448 --> https://bugs.freebsd.org/bugzilla/attachment.cgi?id=3D171448&action= =3Dedit test program demonstrating the issue pipe(2) is documented by as returning 2 file descriptors, one for reading t= he other for writing.=20 "Data can be written to the file descriptor fildes[1] and read from the file descriptor fildes[0]. A read on the file descriptor fildes[0] shall access = data written to the file descriptor fildes[1] on a first-in-first-out basis." The actual implementation ends up wiring fd[0] to fd[1] such that writes on fd[1] provide data that can be read on fd[0] (as required). Oddly writes to fd[0] provide data that can be read in fd[1]. This deviates from the Posix spec (or at least stomps fully into the 'grey' area), resulting in FBSD utilities being rendered portable between unix-like distros. The attached test program demonstrates this behavior. On strictly compliant distros the attached code will result in the child write and parent read failing. --=20 You are receiving this mail because: You are the assignee for the bug.=