This was introduced in 2014-12 to use local binding for external symbols for -fPIE. Now that we have H.J. Lu's GOTPCRELX for years which mostly nullify the benefit of HAVE_LD_PIE_COPYRELOC, HAVE_LD_PIE_COPYRELOC should retire now.
One design goal of -fPIE was to avoid copy relocations. HAVE_LD_PIE_COPYRELOC has deviated from the goal. With this change, the -fPIE behavior of x86-64 will be closer to x86-32 and other targets. --- See https://gcc.gnu.org/legacy-ml/gcc/2019-05/msg00215.html for a list of fixed and unfixed (e.g. gold incompatibility with protected https://sourceware.org/bugzilla/show_bug.cgi?id=19823) issues. If you prefer a longer write-up, see https://maskray.me/blog/2021-01-09-copy-relocations-canonical-plt-entries-and-protected --- gcc/config.in | 6 --- gcc/config/i386/i386.c | 11 +--- gcc/configure | 52 ------------------- gcc/configure.ac | 48 ----------------- gcc/doc/sourcebuild.texi | 3 -- .../gcc.target/i386/pie-copyrelocs-1.c | 14 ----- .../gcc.target/i386/pie-copyrelocs-2.c | 14 ----- .../gcc.target/i386/pie-copyrelocs-3.c | 14 ----- .../gcc.target/i386/pie-copyrelocs-4.c | 17 ------ gcc/testsuite/lib/target-supports.exp | 47 ----------------- 10 files changed, 2 insertions(+), 224 deletions(-) delete mode 100644 gcc/testsuite/gcc.target/i386/pie-copyrelocs-1.c delete mode 100644 gcc/testsuite/gcc.target/i386/pie-copyrelocs-2.c delete mode 100644 gcc/testsuite/gcc.target/i386/pie-copyrelocs-3.c delete mode 100644 gcc/testsuite/gcc.target/i386/pie-copyrelocs-4.c diff --git a/gcc/config.in b/gcc/config.in index e54f59ce0c3..a65bf5d4176 100644 --- a/gcc/config.in +++ b/gcc/config.in @@ -1659,12 +1659,6 @@ #endif -/* Define 0/1 if your linker supports -pie option with copy reloc. */ -#ifndef USED_FOR_TARGET -#undef HAVE_LD_PIE_COPYRELOC -#endif - - /* Define if your PowerPC linker has .gnu.attributes long double support. */ #ifndef USED_FOR_TARGET #undef HAVE_LD_PPC_GNU_ATTR_LONG_DOUBLE diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c index 915f89f571a..5ec3c6fd0c9 100644 --- a/gcc/config/i386/i386.c +++ b/gcc/config/i386/i386.c @@ -10579,11 +10579,7 @@ legitimate_pic_address_disp_p (rtx disp) return true; } else if (!SYMBOL_REF_FAR_ADDR_P (op0) - && (SYMBOL_REF_LOCAL_P (op0) - || (HAVE_LD_PIE_COPYRELOC - && flag_pie - && !SYMBOL_REF_WEAK (op0) - && !SYMBOL_REF_FUNCTION_P (op0))) + && SYMBOL_REF_LOCAL_P (op0) && ix86_cmodel != CM_LARGE_PIC) return true; break; @@ -22892,10 +22888,7 @@ ix86_atomic_assign_expand_fenv (tree *hold, tree *clear, tree *update) static bool ix86_binds_local_p (const_tree exp) { - return default_binds_local_p_3 (exp, flag_shlib != 0, true, true, - (!flag_pic - || (TARGET_64BIT - && HAVE_LD_PIE_COPYRELOC != 0))); + return default_binds_local_p_3 (exp, flag_shlib != 0, true, true, !flag_pic); } #endif diff --git a/gcc/configure b/gcc/configure index f03fe888384..c500f5ca11e 100755 --- a/gcc/configure +++ b/gcc/configure @@ -29968,58 +29968,6 @@ fi { $as_echo "$as_me:${as_lineno-$LINENO}: result: $gcc_cv_ld_pie" >&5 $as_echo "$gcc_cv_ld_pie" >&6; } -{ $as_echo "$as_me:${as_lineno-$LINENO}: checking linker PIE support with copy reloc" >&5 -$as_echo_n "checking linker PIE support with copy reloc... " >&6; } -gcc_cv_ld_pie_copyreloc=no -if test $gcc_cv_ld_pie = yes ; then - if test $in_tree_ld = yes ; then - if test "$gcc_cv_gld_major_version" -eq 2 -a "$gcc_cv_gld_minor_version" -ge 25 -o "$gcc_cv_gld_major_version" -gt 2; then - gcc_cv_ld_pie_copyreloc=yes - fi - elif test x$gcc_cv_as != x -a x$gcc_cv_ld != x ; then - # Check if linker supports -pie option with copy reloc - case "$target" in - i?86-*-linux* | x86_64-*-linux*) - cat > conftest1.s <<EOF - .globl a_glob - .data - .type a_glob, @object - .size a_glob, 4 -a_glob: - .long 2 -EOF - cat > conftest2.s <<EOF - .text - .globl main - .type main, @function -main: - movl %eax, a_glob(%rip) - .size main, .-main - .globl ptr - .section .data.rel,"aw",@progbits - .type ptr, @object -ptr: - .quad a_glob -EOF - if $gcc_cv_as --64 -o conftest1.o conftest1.s > /dev/null 2>&1 \ - && $gcc_cv_ld -shared -melf_x86_64 -o conftest1.so conftest1.o > /dev/null 2>&1 \ - && $gcc_cv_as --64 -o conftest2.o conftest2.s > /dev/null 2>&1 \ - && $gcc_cv_ld -pie -melf_x86_64 -o conftest conftest2.o conftest1.so > /dev/null 2>&1; then - gcc_cv_ld_pie_copyreloc=yes - fi - rm -f conftest conftest1.so conftest1.o conftest2.o conftest1.s conftest2.s - ;; - esac - fi -fi - -cat >>confdefs.h <<_ACEOF -#define HAVE_LD_PIE_COPYRELOC `if test x"$gcc_cv_ld_pie_copyreloc" = xyes; then echo 1; else echo 0; fi` -_ACEOF - -{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $gcc_cv_ld_pie_copyreloc" >&5 -$as_echo "$gcc_cv_ld_pie_copyreloc" >&6; } - { $as_echo "$as_me:${as_lineno-$LINENO}: checking linker EH-compatible garbage collection of sections" >&5 $as_echo_n "checking linker EH-compatible garbage collection of sections... " >&6; } gcc_cv_ld_eh_gc_sections=no diff --git a/gcc/configure.ac b/gcc/configure.ac index e9ba2af548a..d60b22c1708 100644 --- a/gcc/configure.ac +++ b/gcc/configure.ac @@ -5924,54 +5924,6 @@ if test x"$gcc_cv_ld_pie" = xyes; then fi AC_MSG_RESULT($gcc_cv_ld_pie) -AC_MSG_CHECKING(linker PIE support with copy reloc) -gcc_cv_ld_pie_copyreloc=no -if test $gcc_cv_ld_pie = yes ; then - if test $in_tree_ld = yes ; then - if test "$gcc_cv_gld_major_version" -eq 2 -a "$gcc_cv_gld_minor_version" -ge 25 -o "$gcc_cv_gld_major_version" -gt 2; then - gcc_cv_ld_pie_copyreloc=yes - fi - elif test x$gcc_cv_as != x -a x$gcc_cv_ld != x ; then - # Check if linker supports -pie option with copy reloc - case "$target" in - i?86-*-linux* | x86_64-*-linux*) - cat > conftest1.s <<EOF - .globl a_glob - .data - .type a_glob, @object - .size a_glob, 4 -a_glob: - .long 2 -EOF - cat > conftest2.s <<EOF - .text - .globl main - .type main, @function -main: - movl %eax, a_glob(%rip) - .size main, .-main - .globl ptr - .section .data.rel,"aw",@progbits - .type ptr, @object -ptr: - .quad a_glob -EOF - if $gcc_cv_as --64 -o conftest1.o conftest1.s > /dev/null 2>&1 \ - && $gcc_cv_ld -shared -melf_x86_64 -o conftest1.so conftest1.o > /dev/null 2>&1 \ - && $gcc_cv_as --64 -o conftest2.o conftest2.s > /dev/null 2>&1 \ - && $gcc_cv_ld -pie -melf_x86_64 -o conftest conftest2.o conftest1.so > /dev/null 2>&1; then - gcc_cv_ld_pie_copyreloc=yes - fi - rm -f conftest conftest1.so conftest1.o conftest2.o conftest1.s conftest2.s - ;; - esac - fi -fi -AC_DEFINE_UNQUOTED(HAVE_LD_PIE_COPYRELOC, - [`if test x"$gcc_cv_ld_pie_copyreloc" = xyes; then echo 1; else echo 0; fi`], - [Define 0/1 if your linker supports -pie option with copy reloc.]) -AC_MSG_RESULT($gcc_cv_ld_pie_copyreloc) - AC_MSG_CHECKING(linker EH-compatible garbage collection of sections) gcc_cv_ld_eh_gc_sections=no if test $in_tree_ld = yes ; then diff --git a/gcc/doc/sourcebuild.texi b/gcc/doc/sourcebuild.texi index 3a1d6536833..1c8019ea04c 100644 --- a/gcc/doc/sourcebuild.texi +++ b/gcc/doc/sourcebuild.texi @@ -2383,9 +2383,6 @@ Target supports FPU instructions. @item non_strict_align Target does not require strict alignment. -@item pie_copyreloc -The x86-64 target linker supports PIE with copy reloc. - @item rdrand Target supports x86 @code{rdrand} instruction. diff --git a/gcc/testsuite/gcc.target/i386/pie-copyrelocs-1.c b/gcc/testsuite/gcc.target/i386/pie-copyrelocs-1.c deleted file mode 100644 index 7af851bde9b..00000000000 --- a/gcc/testsuite/gcc.target/i386/pie-copyrelocs-1.c +++ /dev/null @@ -1,14 +0,0 @@ -/* Check that GOTPCREL isn't used to access glob_a. */ -/* { dg-do compile { target *-*-linux* } } */ -/* { dg-require-effective-target pie_copyreloc } */ -/* { dg-options "-O2 -fpie" } */ - -extern int glob_a; - -int foo () -{ - return glob_a; -} - -/* glob_a should never be accessed with a GOTPCREL. */ -/* { dg-final { scan-assembler-not "glob_a@GOTPCREL" { target { ! ia32 } } } } */ diff --git a/gcc/testsuite/gcc.target/i386/pie-copyrelocs-2.c b/gcc/testsuite/gcc.target/i386/pie-copyrelocs-2.c deleted file mode 100644 index 19cb97e882c..00000000000 --- a/gcc/testsuite/gcc.target/i386/pie-copyrelocs-2.c +++ /dev/null @@ -1,14 +0,0 @@ -/* Check that GOTPCREL isn't used to access glob_a. */ -/* { dg-do compile { target *-*-linux* } } */ -/* { dg-require-effective-target pie_copyreloc } */ -/* { dg-options "-O2 -fpie" } */ - -int glob_a; - -int foo () -{ - return glob_a; -} - -/* glob_a should never be accessed with a GOTPCREL. */ -/* { dg-final { scan-assembler-not "glob_a@GOTPCREL" { target { ! ia32 } } } } */ diff --git a/gcc/testsuite/gcc.target/i386/pie-copyrelocs-3.c b/gcc/testsuite/gcc.target/i386/pie-copyrelocs-3.c deleted file mode 100644 index c2fa8968e77..00000000000 --- a/gcc/testsuite/gcc.target/i386/pie-copyrelocs-3.c +++ /dev/null @@ -1,14 +0,0 @@ -/* Check that PLT is used to access glob_a. */ -/* { dg-do compile { target *-*-linux* } } */ -/* { dg-require-effective-target pie_copyreloc } */ -/* { dg-options "-O2 -fpie" } */ - -extern int glob_a (void); - -int foo () -{ - return glob_a (); -} - -/* glob_a should be accessed with a PLT. */ -/* { dg-final { scan-assembler "glob_a@PLT" { target { ! ia32 } } } } */ diff --git a/gcc/testsuite/gcc.target/i386/pie-copyrelocs-4.c b/gcc/testsuite/gcc.target/i386/pie-copyrelocs-4.c deleted file mode 100644 index 413cdf381c3..00000000000 --- a/gcc/testsuite/gcc.target/i386/pie-copyrelocs-4.c +++ /dev/null @@ -1,17 +0,0 @@ -/* Check that GOTPCREL is used to access glob_a. */ -/* { dg-do compile { target *-*-linux* } } */ -/* { dg-require-effective-target pie_copyreloc } */ -/* { dg-options "-O2 -fpie" } */ - -extern int glob_a __attribute__((weak)); - -int foo () -{ - if (&glob_a != 0) - return glob_a; - else - return 0; -} - -/* weak glob_a should be accessed with a GOTPCREL. */ -/* { dg-final { scan-assembler "glob_a@GOTPCREL" { target { ! ia32 } } } } */ diff --git a/gcc/testsuite/lib/target-supports.exp b/gcc/testsuite/lib/target-supports.exp index 5700c231065..6f922ebf2ab 100644 --- a/gcc/testsuite/lib/target-supports.exp +++ b/gcc/testsuite/lib/target-supports.exp @@ -10133,53 +10133,6 @@ proc scan-ltrans-tree-dump-dem-not_required_options {} { return "-flto-partition=one" } -# Return 1 if the x86-64 target supports PIE with copy reloc, 0 -# otherwise. Cache the result. - -proc check_effective_target_pie_copyreloc { } { - global tool - global GCC_UNDER_TEST - - if { !([istarget i?86-*-*] || [istarget x86_64-*-*]) } { - return 0 - } - - # Need auto-host.h to check linker support. - if { ![file exists ../../auto-host.h ] } { - return 0 - } - - return [check_cached_effective_target pie_copyreloc { - # Set up and compile to see if linker supports PIE with copy - # reloc. Include the current process ID in the file names to - # prevent conflicts with invocations for multiple testsuites. - - set src pie[pid].c - set obj pie[pid].o - - set f [open $src "w"] - puts $f "#include \"../../auto-host.h\"" - puts $f "#if HAVE_LD_PIE_COPYRELOC == 0" - puts $f "# error Linker does not support PIE with copy reloc." - puts $f "#endif" - close $f - - verbose "check_effective_target_pie_copyreloc compiling testfile $src" 2 - set lines [${tool}_target_compile $src $obj object ""] - - file delete $src - file delete $obj - - if [string match "" $lines] then { - verbose "check_effective_target_pie_copyreloc testfile compilation passed" 2 - return 1 - } else { - verbose "check_effective_target_pie_copyreloc testfile compilation failed" 2 - return 0 - } - }] -} - # Return 1 if the x86 target supports R_386_GOT32X relocation, 0 # otherwise. Cache the result. -- 2.31.1.607.g51e8a6a459-goog
