From owner-freebsd-bugs@freebsd.org Mon Dec 31 11:20:14 2018 Return-Path: Delivered-To: freebsd-bugs@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id C2851142FB05 for ; Mon, 31 Dec 2018 11:20:14 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from mailman.ysv.freebsd.org (mailman.ysv.freebsd.org [IPv6:2001:1900:2254:206a::50:5]) by mx1.freebsd.org (Postfix) with ESMTP id 42C3194EAB for ; Mon, 31 Dec 2018 11:20:14 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: by mailman.ysv.freebsd.org (Postfix) id 02A7D142FB04; Mon, 31 Dec 2018 11:20:14 +0000 (UTC) Delivered-To: bugs@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id B78AB142FB03 for ; Mon, 31 Dec 2018 11:20:13 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from mxrelay.ysv.freebsd.org (mxrelay.ysv.freebsd.org [IPv6:2001:1900:2254:206a::19:3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) server-signature RSA-PSS (4096 bits) client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "mxrelay.ysv.freebsd.org", Issuer "Let's Encrypt Authority X3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 5093894EA8 for ; Mon, 31 Dec 2018 11:20:13 +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 mxrelay.ysv.freebsd.org (Postfix) with ESMTPS id 94A4D179CD for ; Mon, 31 Dec 2018 11:20:12 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from kenobi.freebsd.org ([127.0.1.118]) by kenobi.freebsd.org (8.15.2/8.15.2) with ESMTP id wBVBKChT040204 for ; Mon, 31 Dec 2018 11:20:12 GMT (envelope-from bugzilla-noreply@freebsd.org) Received: (from www@localhost) by kenobi.freebsd.org (8.15.2/8.15.2/Submit) id wBVBKCSw040203 for bugs@FreeBSD.org; Mon, 31 Dec 2018 11:20:12 GMT (envelope-from bugzilla-noreply@freebsd.org) X-Authentication-Warning: kenobi.freebsd.org: www set sender to bugzilla-noreply@freebsd.org using -f From: bugzilla-noreply@freebsd.org To: bugs@FreeBSD.org Subject: [Bug 234523] elf_aux_info() doesn't expose all AT_* vectors Date: Mon, 31 Dec 2018 11:20:12 +0000 X-Bugzilla-Reason: AssignedTo X-Bugzilla-Type: new X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: Base System X-Bugzilla-Component: bin X-Bugzilla-Version: CURRENT X-Bugzilla-Keywords: X-Bugzilla-Severity: Affects Only Me X-Bugzilla-Who: jbeich@FreeBSD.org X-Bugzilla-Status: New X-Bugzilla-Resolution: X-Bugzilla-Priority: --- X-Bugzilla-Assigned-To: 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 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: 2.1.29 Precedence: list List-Id: Bug reports List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 31 Dec 2018 11:20:15 -0000 https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D234523 Bug ID: 234523 Summary: elf_aux_info() doesn't expose all AT_* vectors Product: Base System Version: CURRENT Hardware: Any OS: Any Status: New Severity: Affects Only Me Priority: --- Component: bin Assignee: bugs@FreeBSD.org Reporter: jbeich@FreeBSD.org KERN_PROC_AUXV allows accessing arbitrary AT_* vectors but libc exposes only few via elf_aux_info(3). For example, one may want to rely on libc caching AT_EXECPATH instead of retrieving KERN_PROC_PATHNAME directly. $ cat elf_aux_info.c #include #include #include int main() { char exe[PATH_MAX + 1] =3D {0}; elf_aux_info(AT_EXECPATH, &exe, sizeof(exe)); printf("%s\n", exe); return 0; } $ make elf_aux_info $ ./elf_aux_info $ vs. $ cat getauxval_naive.c #include #include #include #include #include #include static unsigned long getauxval(unsigned long type) { Elf_Auxinfo auxv[AT_COUNT]; size_t len =3D sizeof(auxv); int mib[] =3D { CTL_KERN, KERN_PROC, KERN_PROC_AUXV, getpid(), }; if (sysctl(mib, nitems(mib), auxv, &len, NULL, 0) !=3D -1) { for (size_t i =3D 0; i < nitems(auxv); i++) if ((unsigned long)auxv[i].a_type =3D=3D type) return auxv[i].a_un.a_val; errno =3D ENOENT; } return 0; } int main() { printf("%s\n", (char *)getauxval(AT_EXECPATH)); return 0; } $ make getauxval_naive $ ./getauxval_naive /home/foo/getauxval_naive $ --=20 You are receiving this mail because: You are the assignee for the bug.=