From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from simark.ca by simark.ca with LMTP id qbMKNSZxlGCzMAAAWB0awg (envelope-from ) for ; Thu, 06 May 2021 18:43:50 -0400 Received: by simark.ca (Postfix, from userid 112) id CC80A1F11C; Thu, 6 May 2021 18:43:50 -0400 (EDT) X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on simark.ca X-Spam-Level: X-Spam-Status: No, score=-0.6 required=5.0 tests=MAILING_LIST_MULTI, RDNS_DYNAMIC,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.2 Received: from sourceware.org (ip-8-43-85-97.sourceware.org [8.43.85.97]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by simark.ca (Postfix) with ESMTPS id 389801E783 for ; Thu, 6 May 2021 18:43:49 -0400 (EDT) Received: from server2.sourceware.org (localhost [IPv6:::1]) by sourceware.org (Postfix) with ESMTP id BA38D388F01A; Thu, 6 May 2021 22:43:48 +0000 (GMT) Received: from mail-wm1-f49.google.com (mail-wm1-f49.google.com [209.85.128.49]) by sourceware.org (Postfix) with ESMTPS id A29AA383803D for ; Thu, 6 May 2021 22:43:45 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org A29AA383803D Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=palves.net Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=alves.ped@gmail.com Received: by mail-wm1-f49.google.com with SMTP id l24-20020a7bc4580000b029014ac3b80020so6120698wmi.1 for ; Thu, 06 May 2021 15:43:45 -0700 (PDT) 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:mime-version :content-transfer-encoding; bh=/FKn3PGaMOmBexk6L9RuFQKpHRMlqbQ8sGIfQswUPuk=; b=jBrk25QI1oIhRnjY0WUsDb+03f1p3dnjHsp1oK1C5S1i6Td53mne8IsSBy4vDOE8FX ApcLceuq5aSb8aucj7KFLMmQOGD41sFGZW1uMV0HGmACDFEXvNOfrH3RQVKsMHaXk9iC mOunq+YFlTKHRUnNVk/Eq2VKSyJ2uDZNqkuurMSDJeF4a5MP5E9ETbHxYqfzZCxG4r19 6VISsa/WdFxFgts8T6V8Wq0HAUCJuINhOMGU0ZOEdn11z0d+MXs4lGLRLzcO+USbyWB8 Dix+W51ZhAoyjCbtCLBuZ1kdclx1Jd69YTjRLs/gVzUoPf1SZbZkyJ+Bshj+UM/WmJ6b A47A== X-Gm-Message-State: AOAM530WQo5u7439xKwj81cNjz0wM3us3hjrNpc5SY7Z9SZ6PDnpB2UJ 3jk0e8iOC1S8J4dbRJ9+Z1QZmHHQuFxraQ== X-Google-Smtp-Source: ABdhPJx9pwFIj6M70RlSMRkYyBgictMjuqo3aEDNZrMRys61oT04e3F9bhF66zLE+OqUnPzpcplEZw== X-Received: by 2002:a1c:9a83:: with SMTP id c125mr17514291wme.62.1620341023791; Thu, 06 May 2021 15:43:43 -0700 (PDT) Received: from localhost ([2001:8a0:f932:6a00:6b6e:c7b6:c5a7:aac3]) by smtp.gmail.com with ESMTPSA id 61sm7212679wrm.52.2021.05.06.15.43.42 for (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 06 May 2021 15:43:42 -0700 (PDT) From: Pedro Alves To: gdb-patches@sourceware.org Subject: [PATCH] Don't run personality syscall at configure time; don't check it at all Date: Thu, 6 May 2021 23:43:41 +0100 Message-Id: <20210506224341.398202-1-pedro@palves.net> X-Mailer: git-send-email 2.26.2 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-BeenThere: gdb-patches@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gdb-patches mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: gdb-patches-bounces@sourceware.org Sender: "Gdb-patches" Currently, in order to tell whether support for disabling address space randomization on Linux is available, GDB checks if the personality syscall works, at configure time. I.e., it does a run test, instead of a compile/link test: AC_RUN_IFELSE([PERSONALITY_TEST], [have_personality=true], [have_personality=false], In that case we need to fix configure. The fact that personality works on the build machine says nothing about if configure works on the test machine. This is a bit bogus, because the machine the build is done on may not (and is when you consider distro gdbs) be the machine that eventually runs gdb. It would be better if this were a compile/link test instead, and then at runtime, GDB coped with the personality syscall failing. Actually, GDB already copes. One environment where this is problematic is building GDB in a Docker container -- by default, Docker runs the container with seccomp, with a profile that disables the personality syscall. You can tell Docker to use a less restricted seccomp profile, but I think we should just fix it in GDB. "man 2 personality" says: This system call first appeared in Linux 1.1.20 (and thus first in a stable kernel release with Linux 1.2.0); library support was added in glibc 2.3. ... ADDR_NO_RANDOMIZE (since Linux 2.6.12) With this flag set, disable address-space-layout randomization. glibc 2.3 was released in 2002. Linux 2.6.12 was released in 2005. The original patch that added the configure checks was submitted in 2008. The first version of the patch that was submitted to the list called personality from common code: https://sourceware.org/pipermail/gdb-patches/2008-June/058204.html and then was moved to Linux-specific code: https://sourceware.org/pipermail/gdb-patches/2008-June/058209.html Since HAVE_PERSONALITY is only checked in Linux code, and ADDR_NO_RANDOMIZE exists for over 15 years, I propose just completely removing the configure checks. If for some odd reason, some remotely modern system still needs a configure check, then we can revert this commit but drop the AC_RUN_IFELSE in favor of always doing the AC_LINK_IFELSE cross-compile fallback. gdb/ChangeLog: * linux-nat.c (linux_nat_target::supports_disable_randomization): Remove references to HAVE_PERSONALITY. * nat/linux-personality.c: Remove references to HAVE_PERSONALITY. (maybe_disable_address_space_randomization) (~maybe_disable_address_space_randomizatio): Remove references to HAVE_PERSONALITY. * config.in, configure: Regenerate. gdbserver/ChangeLog: * linux-low.cc: Remove references to HAVE_PERSONALITY. (linux_process_target::supports_disable_randomization): Remove reference to HAVE_PERSONALITY. * config.in, configure: Regenerate. gdbsupport/ChangeLog: * common.m4 (personality test): Remove. --- gdb/config.in | 7 ---- gdb/configure | 74 ------------------------------------- gdb/linux-nat.c | 4 -- gdb/nat/linux-personality.c | 12 +----- gdbserver/config.in | 7 ---- gdbserver/configure | 74 ------------------------------------- gdbserver/linux-low.cc | 11 +----- gdbsupport/common.m4 | 23 ------------ 8 files changed, 2 insertions(+), 210 deletions(-) diff --git a/gdb/config.in b/gdb/config.in index 5d10377b736..99c924f9ba0 100644 --- a/gdb/config.in +++ b/gdb/config.in @@ -96,10 +96,6 @@ /* define if the compiler supports basic C++11 syntax */ #undef HAVE_CXX11 -/* Define to 1 if you have the declaration of `ADDR_NO_RANDOMIZE', and to 0 if - you don't. */ -#undef HAVE_DECL_ADDR_NO_RANDOMIZE - /* Define to 1 if you have the declaration of `asprintf', and to 0 if you don't. */ #undef HAVE_DECL_ASPRINTF @@ -301,9 +297,6 @@ /* Define to 1 if you have the header file. */ #undef HAVE_NLIST_H -/* Define if you support the personality syscall. */ -#undef HAVE_PERSONALITY - /* Define to 1 if you have the `pipe' function. */ #undef HAVE_PIPE diff --git a/gdb/configure b/gdb/configure index b47de77bf64..cdc112e10dc 100755 --- a/gdb/configure +++ b/gdb/configure @@ -13819,80 +13819,6 @@ fi done - ac_fn_c_check_decl "$LINENO" "ADDR_NO_RANDOMIZE" "ac_cv_have_decl_ADDR_NO_RANDOMIZE" "#include -" -if test "x$ac_cv_have_decl_ADDR_NO_RANDOMIZE" = xyes; then : - ac_have_decl=1 -else - ac_have_decl=0 -fi - -cat >>confdefs.h <<_ACEOF -#define HAVE_DECL_ADDR_NO_RANDOMIZE $ac_have_decl -_ACEOF - - - if test "$cross_compiling" = yes; then : - cat confdefs.h - <<_ACEOF >conftest.$ac_ext -/* end confdefs.h. */ -#include -int -main () -{ - - # if !HAVE_DECL_ADDR_NO_RANDOMIZE - # define ADDR_NO_RANDOMIZE 0x0040000 - # endif - /* Test the flag could be set and stays set. */ - personality (personality (0xffffffff) | ADDR_NO_RANDOMIZE); - if (!(personality (personality (0xffffffff)) & ADDR_NO_RANDOMIZE)) - return 1 - ; - return 0; -} -_ACEOF -if ac_fn_c_try_link "$LINENO"; then : - have_personality=true -else - have_personality=false -fi -rm -f core conftest.err conftest.$ac_objext \ - conftest$ac_exeext conftest.$ac_ext -else - cat confdefs.h - <<_ACEOF >conftest.$ac_ext -/* end confdefs.h. */ -#include -int -main () -{ - - # if !HAVE_DECL_ADDR_NO_RANDOMIZE - # define ADDR_NO_RANDOMIZE 0x0040000 - # endif - /* Test the flag could be set and stays set. */ - personality (personality (0xffffffff) | ADDR_NO_RANDOMIZE); - if (!(personality (personality (0xffffffff)) & ADDR_NO_RANDOMIZE)) - return 1 - ; - return 0; -} -_ACEOF -if ac_fn_c_try_run "$LINENO"; then : - have_personality=true -else - have_personality=false -fi -rm -f core *.core core.conftest.* gmon.out bb.out conftest$ac_exeext \ - conftest.$ac_objext conftest.beam conftest.$ac_ext -fi - - if $have_personality - then - -$as_echo "#define HAVE_PERSONALITY 1" >>confdefs.h - - fi - ac_fn_c_check_decl "$LINENO" "strstr" "ac_cv_have_decl_strstr" "$ac_includes_default" if test "x$ac_cv_have_decl_strstr" = xyes; then : ac_have_decl=1 diff --git a/gdb/linux-nat.c b/gdb/linux-nat.c index c45e335a762..e595c71c3d3 100644 --- a/gdb/linux-nat.c +++ b/gdb/linux-nat.c @@ -4022,11 +4022,7 @@ linux_nat_target::supports_multi_process () bool linux_nat_target::supports_disable_randomization () { -#ifdef HAVE_PERSONALITY return true; -#else - return false; -#endif } /* SIGCHLD handler that serves two purposes: In non-stop/async mode, diff --git a/gdb/nat/linux-personality.c b/gdb/nat/linux-personality.c index 87d19218626..9ce345bc6de 100644 --- a/gdb/nat/linux-personality.c +++ b/gdb/nat/linux-personality.c @@ -20,12 +20,7 @@ #include "gdbsupport/common-defs.h" #include "nat/linux-personality.h" -#ifdef HAVE_PERSONALITY -# include -# if !HAVE_DECL_ADDR_NO_RANDOMIZE -# define ADDR_NO_RANDOMIZE 0x0040000 -# endif /* ! HAVE_DECL_ADDR_NO_RANDOMIZE */ -#endif /* HAVE_PERSONALITY */ +#include /* See comment on nat/linux-personality.h. */ @@ -34,7 +29,6 @@ maybe_disable_address_space_randomization (int disable_randomization) : m_personality_set (false), m_personality_orig (0) { -#ifdef HAVE_PERSONALITY if (disable_randomization) { errno = 0; @@ -49,14 +43,11 @@ maybe_disable_address_space_randomization (int disable_randomization) warning (_("Error disabling address space randomization: %s"), safe_strerror (errno)); } -#endif /* HAVE_PERSONALITY */ } maybe_disable_address_space_randomization:: ~maybe_disable_address_space_randomization () { -#ifdef HAVE_PERSONALITY - if (m_personality_set) { errno = 0; @@ -65,5 +56,4 @@ maybe_disable_address_space_randomization:: warning (_("Error restoring address space randomization: %s"), safe_strerror (errno)); } -#endif /* HAVE_PERSONALITY */ } diff --git a/gdbserver/config.in b/gdbserver/config.in index 99391b4acff..611bfd7aa76 100644 --- a/gdbserver/config.in +++ b/gdbserver/config.in @@ -31,10 +31,6 @@ /* define if the compiler supports basic C++11 syntax */ #undef HAVE_CXX11 -/* Define to 1 if you have the declaration of `ADDR_NO_RANDOMIZE', and to 0 if - you don't. */ -#undef HAVE_DECL_ADDR_NO_RANDOMIZE - /* Define to 1 if you have the declaration of `asprintf', and to 0 if you don't. */ #undef HAVE_DECL_ASPRINTF @@ -182,9 +178,6 @@ /* Define to 1 if you have the header file. */ #undef HAVE_NETINET_TCP_H -/* Define if you support the personality syscall. */ -#undef HAVE_PERSONALITY - /* Define to 1 if you have the `pipe' function. */ #undef HAVE_PIPE diff --git a/gdbserver/configure b/gdbserver/configure index 032b4ae65bb..aab72c0b8c5 100755 --- a/gdbserver/configure +++ b/gdbserver/configure @@ -7130,80 +7130,6 @@ fi done - ac_fn_c_check_decl "$LINENO" "ADDR_NO_RANDOMIZE" "ac_cv_have_decl_ADDR_NO_RANDOMIZE" "#include -" -if test "x$ac_cv_have_decl_ADDR_NO_RANDOMIZE" = xyes; then : - ac_have_decl=1 -else - ac_have_decl=0 -fi - -cat >>confdefs.h <<_ACEOF -#define HAVE_DECL_ADDR_NO_RANDOMIZE $ac_have_decl -_ACEOF - - - if test "$cross_compiling" = yes; then : - cat confdefs.h - <<_ACEOF >conftest.$ac_ext -/* end confdefs.h. */ -#include -int -main () -{ - - # if !HAVE_DECL_ADDR_NO_RANDOMIZE - # define ADDR_NO_RANDOMIZE 0x0040000 - # endif - /* Test the flag could be set and stays set. */ - personality (personality (0xffffffff) | ADDR_NO_RANDOMIZE); - if (!(personality (personality (0xffffffff)) & ADDR_NO_RANDOMIZE)) - return 1 - ; - return 0; -} -_ACEOF -if ac_fn_c_try_link "$LINENO"; then : - have_personality=true -else - have_personality=false -fi -rm -f core conftest.err conftest.$ac_objext \ - conftest$ac_exeext conftest.$ac_ext -else - cat confdefs.h - <<_ACEOF >conftest.$ac_ext -/* end confdefs.h. */ -#include -int -main () -{ - - # if !HAVE_DECL_ADDR_NO_RANDOMIZE - # define ADDR_NO_RANDOMIZE 0x0040000 - # endif - /* Test the flag could be set and stays set. */ - personality (personality (0xffffffff) | ADDR_NO_RANDOMIZE); - if (!(personality (personality (0xffffffff)) & ADDR_NO_RANDOMIZE)) - return 1 - ; - return 0; -} -_ACEOF -if ac_fn_c_try_run "$LINENO"; then : - have_personality=true -else - have_personality=false -fi -rm -f core *.core core.conftest.* gmon.out bb.out conftest$ac_exeext \ - conftest.$ac_objext conftest.beam conftest.$ac_ext -fi - - if $have_personality - then - -$as_echo "#define HAVE_PERSONALITY 1" >>confdefs.h - - fi - ac_fn_c_check_decl "$LINENO" "strstr" "ac_cv_have_decl_strstr" "$ac_includes_default" if test "x$ac_cv_have_decl_strstr" = xyes; then : ac_have_decl=1 diff --git a/gdbserver/linux-low.cc b/gdbserver/linux-low.cc index 251a54f5c4a..27556ffb88a 100644 --- a/gdbserver/linux-low.cc +++ b/gdbserver/linux-low.cc @@ -60,12 +60,7 @@ #endif #include "nat/linux-namespaces.h" -#ifdef HAVE_PERSONALITY -# include -# if !HAVE_DECL_ADDR_NO_RANDOMIZE -# define ADDR_NO_RANDOMIZE 0x0040000 -# endif -#endif +#include #ifndef O_LARGEFILE #define O_LARGEFILE 0 @@ -6231,11 +6226,7 @@ linux_process_target::core_of_thread (ptid_t ptid) bool linux_process_target::supports_disable_randomization () { -#ifdef HAVE_PERSONALITY return true; -#else - return false; -#endif } bool diff --git a/gdbsupport/common.m4 b/gdbsupport/common.m4 index 3ed95dabc85..2e709dbbdbb 100644 --- a/gdbsupport/common.m4 +++ b/gdbsupport/common.m4 @@ -55,29 +55,6 @@ AC_DEFUN([GDB_AC_COMMON], [ ptrace64 sbrk setns sigaltstack sigprocmask \ setpgid setpgrp getrusage getauxval]) - dnl Check if we can disable the virtual address space randomization. - dnl The functionality of setarch -R. - AC_CHECK_DECLS([ADDR_NO_RANDOMIZE],,, [#include ]) - define([PERSONALITY_TEST], [AC_LANG_PROGRAM([#include ], [ - # if !HAVE_DECL_ADDR_NO_RANDOMIZE - # define ADDR_NO_RANDOMIZE 0x0040000 - # endif - /* Test the flag could be set and stays set. */ - personality (personality (0xffffffff) | ADDR_NO_RANDOMIZE); - if (!(personality (personality (0xffffffff)) & ADDR_NO_RANDOMIZE)) - return 1])]) - AC_RUN_IFELSE([PERSONALITY_TEST], - [have_personality=true], - [have_personality=false], - [AC_LINK_IFELSE([PERSONALITY_TEST], - [have_personality=true], - [have_personality=false])]) - if $have_personality - then - AC_DEFINE([HAVE_PERSONALITY], 1, - [Define if you support the personality syscall.]) - fi - AC_CHECK_DECLS([strstr]) # ----------------------- # base-commit: ec66d6ea54679d00c1f0d52a5a9fa0cbb8b86d47 -- 2.26.2