From patchwork Thu Jan 5 12:37:05 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Adhemerval Zanella Netto X-Patchwork-Id: 18790 Received: (qmail 34528 invoked by alias); 5 Jan 2017 12:37:25 -0000 Mailing-List: contact libc-alpha-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Unsubscribe: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: libc-alpha-owner@sourceware.org Delivered-To: mailing list libc-alpha@sourceware.org Received: (qmail 34497 invoked by uid 89); 5 Jan 2017 12:37:24 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-1.4 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_NONE, RCVD_IN_SORBS_SPAM, SPF_PASS autolearn=no version=3.3.2 spammy=__gnuc_prereq, __GNUC_PREREQ, Hx-languages-length:5430, 917 X-HELO: mail-yw0-f177.google.com X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:subject:date:message-id; bh=+orGbxN6gYEvVn3q3EFz490X+Imp5Ey0+YLyu07rQYw=; b=XdmiVOdMZ+lQSMUcHUTg9DvfktW5nrja8ytqGedlqP7AifSOqS9oqzHeuQZo/nybNd L2CovAF2RPZpdFFuXNcbBweRwyUz58wM05CPcTR9z2OUUTkUScQOfCNyLzmQewvUwlpZ qPkV71EkSwjvnV32clNtlmwshVTcHgltXSD3/aT/F5JMCXWajifwhohjFZbTdEC+jML7 y6j6JAZYoj2pCpk92JEOxpJPyxGH3GAl9N8ozyMKOvH9pfOENJF2sQxJlgZz0LW8RVo2 BEmW19TOJAY3Lzm6746wagdQqiROS0bw2t5jwIPGhFxOnvILstcs3zA61aGAAQR0oSvP h7/A== X-Gm-Message-State: AIkVDXK4yQZBjiV786y2vkq1H9RL2oeyPTicOL0EAV3pY0LcX5EQTiv32hHs3fAhF8DHmGIr X-Received: by 10.129.72.197 with SMTP id v188mr64346479ywa.22.1483619832650; Thu, 05 Jan 2017 04:37:12 -0800 (PST) From: Adhemerval Zanella To: libc-alpha@sourceware.org Subject: [PATCH] Use fortify macros for b{zero, copy} along decl from strings.h Date: Thu, 5 Jan 2017 10:37:05 -0200 Message-Id: <1483619825-16670-1-git-send-email-adhemerval.zanella@linaro.org> As described in BZ#20558, bzero and bcopy declaration can only benefit from fortified macros when decl came from string.h and when __USE_MISC is defined (default behaviour). This is due no standard includes those functions in string.h, so they are only declared if __USE_MISC is defined (as pointed out in comment 4). However fortification should be orthogona to other features test macros, i.e, any function should be fortified if that function is declared. To fix this behavior, the patch moved the bzero, bcopy, and __explicit_bzero_chk to a common header (string/bits/strings_fortified.h) and explicit fortified inclusion macros similar to string.h is added on strings.h. This allows to get fortified declarions by only including strings.h. Checked on x86_64-linux-gnu and along on a bootstrap installation to check if the fortified are correctly triggered with example from bug report. [BZ #20558] * string/bits/string3.h [__USE_MISC] (bcopy): Move to strings_fortified.h. [__USE_MISC] (bzero): Likewise. [__USE_MISC] (explicit_bzero): Likewise. * string/strings.h: Include strings_fortified.h. * string/Makefile (headers): Add strings_fortified.h. * string/bits/strings_fortified.h: New file. * include/bits/strings_fortified.h: Likewise. --- ChangeLog | 12 +++++++++++ include/bits/strings_fortified.h | 1 + string/Makefile | 3 ++- string/bits/string3.h | 21 +------------------- string/bits/strings_fortified.h | 43 ++++++++++++++++++++++++++++++++++++++++ string/strings.h | 8 ++++++++ 6 files changed, 67 insertions(+), 21 deletions(-) create mode 100644 include/bits/strings_fortified.h create mode 100644 string/bits/strings_fortified.h diff --git a/include/bits/strings_fortified.h b/include/bits/strings_fortified.h new file mode 100644 index 0000000..77219c1 --- /dev/null +++ b/include/bits/strings_fortified.h @@ -0,0 +1 @@ +#include diff --git a/string/Makefile b/string/Makefile index aaa371f..04e9da9 100644 --- a/string/Makefile +++ b/string/Makefile @@ -24,7 +24,8 @@ include ../Makeconfig headers := string.h strings.h memory.h endian.h bits/endian.h \ argz.h envz.h byteswap.h bits/byteswap.h bits/byteswap-16.h \ - bits/string.h bits/string2.h bits/string3.h + bits/string.h bits/string2.h bits/string3.h \ + bits/strings_fortified.h routines := strcat strchr strcmp strcoll strcpy strcspn \ strverscmp strdup strndup \ diff --git a/string/bits/string3.h b/string/bits/string3.h index fe0c161..0b0a377 100644 --- a/string/bits/string3.h +++ b/string/bits/string3.h @@ -91,26 +91,7 @@ __NTH (memset (void *__dest, int __ch, size_t __len)) } #ifdef __USE_MISC -__fortify_function void -__NTH (bcopy (const void *__src, void *__dest, size_t __len)) -{ - (void) __builtin___memmove_chk (__dest, __src, __len, __bos0 (__dest)); -} - -__fortify_function void -__NTH (bzero (void *__dest, size_t __len)) -{ - (void) __builtin___memset_chk (__dest, '\0', __len, __bos0 (__dest)); -} - -void __explicit_bzero_chk (void *__dest, size_t __len, size_t __destlen) - __THROW __nonnull ((1)); - -__fortify_function void -__NTH (explicit_bzero (void *__dest, size_t __len)) -{ - __explicit_bzero_chk (__dest, __len, __bos0 (__dest)); -} +# include #endif __fortify_function char * diff --git a/string/bits/strings_fortified.h b/string/bits/strings_fortified.h new file mode 100644 index 0000000..fd396f9 --- /dev/null +++ b/string/bits/strings_fortified.h @@ -0,0 +1,43 @@ +/* Fortify macros for strings.h functions. + Copyright (C) 2017 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + . */ + +#ifndef __STRINGS_FORTIFIED +# define __STRINGS_FORTIFIED 1 + +__fortify_function void +__NTH (bcopy (const void *__src, void *__dest, size_t __len)) +{ + (void) __builtin___memmove_chk (__dest, __src, __len, __bos0 (__dest)); +} + +__fortify_function void +__NTH (bzero (void *__dest, size_t __len)) +{ + (void) __builtin___memset_chk (__dest, '\0', __len, __bos0 (__dest)); +} + +void __explicit_bzero_chk (void *__dest, size_t __len, size_t __destlen) + __THROW __nonnull ((1)); + +__fortify_function void +__NTH (explicit_bzero (void *__dest, size_t __len)) +{ + __explicit_bzero_chk (__dest, __len, __bos0 (__dest)); +} + +#endif diff --git a/string/strings.h b/string/strings.h index ece21c8..69b75b1 100644 --- a/string/strings.h +++ b/string/strings.h @@ -136,4 +136,12 @@ __END_DECLS #endif /* string.h */ +#if __GNUC_PREREQ (3,4) && __USE_FORTIFY_LEVEL > 0 \ + && defined __fortify_function +/* Functions with security checks. */ +# if defined __USE_MISC || !defined __USE_XOPEN2K8 +# include +# endif +#endif + #endif /* strings.h */