From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 7814) id 1C83B3857800; Fri, 27 Aug 2021 23:49:06 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 1C83B3857800 Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit From: Fangrui Song To: glibc-cvs@sourceware.org Subject: [glibc/maskray/grte] x86_64: Remove unneeded static PIE check for undefined weak diagnostic X-Act-Checkin: glibc X-Git-Author: Fangrui Song X-Git-Refname: refs/heads/maskray/grte X-Git-Oldrev: 1c22c0b40ceac0403681c59bf0b4565b17d8bdec X-Git-Newrev: 2000c9a6230394bf03760ca0e111a0f5a6d7b056 Message-Id: <20210827234906.1C83B3857800@sourceware.org> Date: Fri, 27 Aug 2021 23:49:06 +0000 (GMT) X-BeenThere: glibc-cvs@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Glibc-cvs mailing list List-Unsubscribe: , List-Archive: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 27 Aug 2021 23:49:06 -0000 https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=2000c9a6230394bf03760ca0e111a0f5a6d7b056 commit 2000c9a6230394bf03760ca0e111a0f5a6d7b056 Author: Fangrui Song Date: Thu Jul 8 14:26:22 2021 -0700 x86_64: Remove unneeded static PIE check for undefined weak diagnostic https://sourceware.org/bugzilla/show_bug.cgi?id=21782 dropped an ld diagnostic for R_X86_64_PC32 referencing an undefined weak symbol in -pie links. Arguably keeping the diagnostic like other ports is more correct, since statically resolving movl foo(%rip), %eax to the link-time zero address produces a corrupted output. It turns out that --enable-static-pie builds do not depend on the ld behavior. GCC generates GOT indirection for weak declarations for -fPIE/-fPIC, so what ld does with the PC-relative relocation doesn't really matter. Reviewed-by: H.J. Lu Diff: --- sysdeps/x86_64/configure | 33 --------------------------------- sysdeps/x86_64/configure.ac | 25 ------------------------- 2 files changed, 58 deletions(-) diff --git a/sysdeps/x86_64/configure b/sysdeps/x86_64/configure old mode 100644 new mode 100755 index 8674d14569..efef46b1b7 --- a/sysdeps/x86_64/configure +++ b/sysdeps/x86_64/configure @@ -85,39 +85,6 @@ if test x"$build_mathvec" = xnotset; then build_mathvec=yes fi -if test "$static_pie" = yes; then - { $as_echo "$as_me:${as_lineno-$LINENO}: checking for linker static PIE support" >&5 -$as_echo_n "checking for linker static PIE support... " >&6; } -if ${libc_cv_ld_static_pie+:} false; then : - $as_echo_n "(cached) " >&6 -else - cat > conftest.s <<\EOF - .text - .global _start - .weak foo -_start: - leaq foo(%rip), %rax -EOF - libc_cv_pie_option="-Wl,-pie" - if { ac_try='${CC-cc} $CFLAGS $CPPFLAGS $LDFLAGS -nostartfiles -nostdlib $no_ssp $libc_cv_pie_option -o conftest conftest.s 1>&5' - { { eval echo "\"\$as_me\":${as_lineno-$LINENO}: \"$ac_try\""; } >&5 - (eval $ac_try) 2>&5 - ac_status=$? - $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5 - test $ac_status = 0; }; }; then - libc_cv_ld_static_pie=yes - else - libc_cv_ld_static_pie=no - fi -rm -f conftest* -fi -{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $libc_cv_ld_static_pie" >&5 -$as_echo "$libc_cv_ld_static_pie" >&6; } - if test "$libc_cv_ld_static_pie" != yes; then - as_fn_error $? "linker support for static PIE needed" "$LINENO" 5 - fi -fi - $as_echo "#define PI_STATIC_AND_HIDDEN 1" >>confdefs.h diff --git a/sysdeps/x86_64/configure.ac b/sysdeps/x86_64/configure.ac index b7d2c0124f..fa86e953ee 100644 --- a/sysdeps/x86_64/configure.ac +++ b/sysdeps/x86_64/configure.ac @@ -44,31 +44,6 @@ if test x"$build_mathvec" = xnotset; then build_mathvec=yes fi -dnl Check if linker supports static PIE with the fix for -dnl -dnl https://sourceware.org/bugzilla/show_bug.cgi?id=21782 -dnl -if test "$static_pie" = yes; then - AC_CACHE_CHECK(for linker static PIE support, libc_cv_ld_static_pie, [dnl -cat > conftest.s <<\EOF - .text - .global _start - .weak foo -_start: - leaq foo(%rip), %rax -EOF - libc_cv_pie_option="-Wl,-pie" - if AC_TRY_COMMAND(${CC-cc} $CFLAGS $CPPFLAGS $LDFLAGS -nostartfiles -nostdlib $no_ssp $libc_cv_pie_option -o conftest conftest.s 1>&AS_MESSAGE_LOG_FD); then - libc_cv_ld_static_pie=yes - else - libc_cv_ld_static_pie=no - fi -rm -f conftest*]) - if test "$libc_cv_ld_static_pie" != yes; then - AC_MSG_ERROR([linker support for static PIE needed]) - fi -fi - dnl It is always possible to access static and hidden symbols in an dnl position independent way. AC_DEFINE(PI_STATIC_AND_HIDDEN)