From patchwork Fri Sep 25 10:42:43 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Danny Milosavljevic X-Patchwork-Id: 24292 Return-Path: X-Original-To: patchwork@mira.cbaines.net Delivered-To: patchwork@mira.cbaines.net Received: by mira.cbaines.net (Postfix, from userid 113) id 27B8527BBE9; Fri, 25 Sep 2020 11:44:09 +0100 (BST) X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on mira.cbaines.net X-Spam-Level: X-Spam-Status: No, score=-2.9 required=5.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_MSPIKE_H4,RCVD_IN_MSPIKE_WL,URIBL_BLOCKED autolearn=unavailable autolearn_force=no version=3.4.2 Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mira.cbaines.net (Postfix) with ESMTPS id BA05C27BBE8 for ; Fri, 25 Sep 2020 11:44:08 +0100 (BST) Received: from localhost ([::1]:39132 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kLlCx-0007kT-Nw for patchwork@mira.cbaines.net; Fri, 25 Sep 2020 06:44:07 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:48610) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kLlCs-0007j0-E5 for guix-patches@gnu.org; Fri, 25 Sep 2020 06:44:02 -0400 Received: from debbugs.gnu.org ([209.51.188.43]:59480) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1kLlCs-0002SH-5G for guix-patches@gnu.org; Fri, 25 Sep 2020 06:44:02 -0400 Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.84_2) (envelope-from ) id 1kLlCs-0006hs-3Z for guix-patches@gnu.org; Fri, 25 Sep 2020 06:44:02 -0400 X-Loop: help-debbugs@gnu.org Subject: [bug#43591] [PATCH v2 core-updates] gnu: glibc-final: Catch all cases of a glibc user not requesting 64-bit offsets and then using readdir regardless. Resent-From: Danny Milosavljevic Original-Sender: "Debbugs-submit" Resent-CC: guix-patches@gnu.org Resent-Date: Fri, 25 Sep 2020 10:44:02 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 43591 X-GNU-PR-Package: guix-patches X-GNU-PR-Keywords: patch To: 43591@debbugs.gnu.org Cc: Danny Milosavljevic Received: via spool by 43591-submit@debbugs.gnu.org id=B43591.160103060125720 (code B ref 43591); Fri, 25 Sep 2020 10:44:02 +0000 Received: (at 43591) by debbugs.gnu.org; 25 Sep 2020 10:43:21 +0000 Received: from localhost ([127.0.0.1]:42793 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1kLlCD-0006gl-Dr for submit@debbugs.gnu.org; Fri, 25 Sep 2020 06:43:21 -0400 Received: from dd26836.kasserver.com ([85.13.145.193]:38540) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1kLlCB-0006gd-VZ for 43591@debbugs.gnu.org; Fri, 25 Sep 2020 06:43:20 -0400 Received: from dayas.lan (80-110-126-103.cgn.dynamic.surfer.at [80.110.126.103]) by dd26836.kasserver.com (Postfix) with ESMTPSA id 1C9493365A25; Fri, 25 Sep 2020 12:43:18 +0200 (CEST) From: Danny Milosavljevic Date: Fri, 25 Sep 2020 12:42:43 +0200 Message-Id: <20200925104243.2298-1-dannym@scratchpost.org> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20200925122004.38275411@scratchpost.org> References: <20200925122004.38275411@scratchpost.org> MIME-Version: 1.0 Tags: patch X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.18 Precedence: list X-BeenThere: guix-patches@gnu.org List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: guix-patches-bounces+patchwork=mira.cbaines.net@gnu.org Sender: "Guix-patches" X-getmail-retrieved-from-mailbox: Patches * gnu/packages/commencement.scm (glibc-final): Catch all cases of a glibc user not requesting 64-bit offsets and then using readdir. --- gnu/packages/commencement.scm | 68 ++++++++++++++++++++++++++++++++++- 1 file changed, 67 insertions(+), 1 deletion(-) diff --git a/gnu/packages/commencement.scm b/gnu/packages/commencement.scm index e5a4caa95c..284fa65d20 100644 --- a/gnu/packages/commencement.scm +++ b/gnu/packages/commencement.scm @@ -3462,7 +3462,73 @@ exec ~a/bin/~a-~a -B~a/lib -Wl,-dynamic-linker -Wl,~a/~a \"$@\"~%" ,hurd-headers-boot0) '()) ,@(package-outputs glibc-final-with-bootstrap-bash)) - ,@(package-arguments glibc-final-with-bootstrap-bash))))) + ,@(substitute-keyword-arguments + (package-arguments glibc-final-with-bootstrap-bash) + ((#:phases phases) + `(modify-phases ,phases + (add-after 'unpack 'patch-dirent + (lambda* (#:key outputs #:allow-other-keys) + ;; Linux kernel file offsets are always 64 bits. + ;; But userspace can be built to use 32 bit offsets. + ;; + ;; "struct dirent", returned by readdir, uses d_off to store + ;; such an "offset" that it got from the Linux kernel. + ;; In the case of ext4 that "offset" is actually a 64 bit + ;; cookie which includes a hash value. + ;; + ;; Therefore, there are cases where such an offset that it got + ;; from the Linux kernel does not fit in the "struct dirent" + ;; field "d_off". + ;; + ;; If the guest system's glibc is 32 bit AND uses 32 bit + ;; file offsets it is going to be very confused. + ;; It does check whether d_off fits into the structure + ;; it gives back to the user--and it doesn't fit. Hence readdir + ;; fails, with errno == EOVERFLOW (which is undocumented and thus + ;; an API error). + ;; This manifests itself in simple directory reads not working + ;; anymore in parts of cmake, for example. + ;; + ;; This manifested in Guix when building stuff for + ;; ARMHF on a x86_64 build host using QEMU transparent emulation. + ;; + ;; There is a very simple and complete way to avoid this problem: + ;; Just always use 64 bit offsets in user space programs (also + ;; on 32 bit machines). The Linux kernel does that already + ;; anyway. + ;; + ;; Note: We might want to avoid using 64 bit when bootstrapping + ;; using mescc (since mescc doesn't directly support 64 bit + ;; values)--but then bootstrapping has to be done on a + ;; file system other than ext4, or on ext4 with the feature + ;; "dir_index" disabled. + ;; + ;; The change below does not affect 64 bit users. + ;; + ;; See . + (let ((port (open-file "dirent/dirent.h" "a"))) + (display " +#ifndef _LIBC +#if __SIZEOF_LONG__ < 8 +#ifndef __USE_FILE_OFFSET64 +#if defined(_FILE_OFFSET_BITS) && _FILE_OFFSET_BITS == 32 +#warning \"Using -D_FILE_OFFSET_BITS=32 and using readdir is a bad idea, see \" +#else +#undef readdir +#define readdir @READDIR_WITHOUT_FILE_OFFSET64_IS_A_REALLY_BAD_IDEA@ +#endif +#endif +#endif +#endif +" port) + (close-port port)) + ;; This file includes and thus checks sanity already. + ;; TODO: Check dirent/scandir-tail.c, dirent/scandir64-tail.c. + (substitute* "posix/glob.c" + (("(#[ ]*define[ ][ ]*readdir)") " +#undef readdir +#define readdir")) + #t))))))))) (define/system-dependent gcc-boot0-wrapped ;; Make the cross-tools GCC-BOOT0 and BINUTILS-BOOT0 available under the