lördag 16 november 2013 20.37.58 skrev Ryan Hill:
> On Wed, 13 Nov 2013 23:28:45 +0100
>
> Magnus Granberg <zo...@gentoo.org> wrote:
> > Hi
> > This patchset will add a new configure options --enable-default-pie.
> > With the new option enable will make it pass -fPIE and -pie from the gcc
> > and g++ frontend. Have only add the support for two targets but should
> > work on more targes. In configure.ac we add the new option. We can't
> > compile the compiler or the crt stuff with -fPIE it will brake the PCH
> > and the crtbegin and crtend files. The disabling is done in the
> > Makefiles. The needed spec is added to DRIVER_SELF_SPECS. We disable all
> > the profiling test for the linking will fail.Tested on x86_64 linux
> > (Gentoo).
> >
> > /Magnus Granberg
>
> Hey Magnus. Some nits:
......
> > +for C, C++, ObjC, ObjC++, if none of @option{-fno-PIE},
> > @option{-fno-pie},
> > +@option{-fPIC}, @option{-fpic}, @option{-fno-PIC}, @option{-fno-pic},
> > +@option{-nostdlib}, @option{-nostartfiles}, @option{-shared},
> > +@option{-nodefaultlibs}, nor @option{static} are found.
>
> Looks like nodefaultlibs is missing from PIE_DRIVER_SELF_SPECS or this needs
> to be updated.
>
> Thanks!
Thankyou for the nits. Have updated the patches with the fixes.
The same changlog should work in my first post about this new option.
>Mike Stump wrote
>Ick. Would be nice to figure out on what systems one can do this and just do
>it without the configure option. Is there some reason that we need an option
>for it?
It would work well on most *-*-linux* targets but i don't have all the
hardware for testing and I agre with Ian that it should not be default enable.
/Magnus Granberg
--- a/gcc/testsuite/gcc.dg/default-pie.c 2013-11-09 21:07:16.741479728 +0100
+++ b/gcc/testsuite/gcc.dg/default-pie.c 2013-11-09 21:05:07.801479218 +0100
@@ -0,0 +1,12 @@
+/* { dg-do compile { target *-*-linux* *-*-gnu* } } */
+/* { dg-require-effective-target default_pie } */
+/* { dg-options "-O2" } */
+int foo (void);
+
+int
+main (void)
+{
+ return foo ();
+}
+
+/* { dg-final { scan-assembler "foo@PLT" } } */
--- a/gcc/testsuite/g++.dg/other/anon5.C 2012-11-10 15:34:42.000000000 +0100
+++ b/gcc/testsuite/g++.dg/other/anon5.C 2013-11-09 14:49:52.281390127 +0100
@@ -1,5 +1,6 @@
// PR c++/34094
// { dg-do link { target { ! { *-*-darwin* *-*-hpux* *-*-solaris2.* } } } }
+// { dg-skip-if "" { default_pie } { "*" } { "" } }
// { dg-options "-g" }
// Ignore additional message on powerpc-ibm-aix
// { dg-prune-output "obtain more information" } */
--- a/gcc/testsuite/lib/target-supports.exp 2013-10-01 11:18:30.000000000 +0200
+++ b/gcc/testsuite/lib/target-supports.exp 2013-10-25 22:01:46.743388469 +0200
@@ -474,6 +474,11 @@ proc check_profiling_available { test_wh
}
}
+ # Profiling don't work with default -fPIE -pie.
+ if { [check_effective_target_default_pie] } {
+ return 0
+ }
+
# Support for -p on solaris2 relies on mcrt1.o which comes with the
# vendor compiler. We cannot reliably predict the directory where the
# vendor compiler (and thus mcrt1.o) is installed so we can't
@@ -839,6 +844,14 @@ proc check_effective_target_pie { } {
return 0
}
+# Return 1 if -pie, -fPIE are default enable, 0 otherwise.
+
+proc check_effective_target_default_pie { } {
+ global ENABLE_DEFAULT_PIE
+ return [info exists ENABLE_DEFAULT_PIE]
+ return 0
+}
+
# Return true if the target supports -mpaired-single (as used on MIPS).
proc check_effective_target_mpaired_single { } {
--- a/gcc/config/gnu-user.h 2013-08-20 10:31:40.000000000 +0200
+++ b/gcc/config/gnu-user.h 2013-10-23 22:01:42.337238981 +0200
@@ -134,3 +134,17 @@ see the files COPYING3 and COPYING.RUNTI
/* Additional libraries needed by -static-libtsan. */
#undef STATIC_LIBTSAN_LIBS
#define STATIC_LIBTSAN_LIBS "-ldl -lpthread"
+
+/* We use this to make the compiler use -fPIE as default and link
+ with -pie. */
+#ifdef ENABLE_DEFAULT_PIE
+#define PIE_DRIVER_SELF_SPECS \
+"%{pie|fpic|fPIC|fpie|fPIE|fno-pic|fno-PIC|fno-pie|fno-PIE| \
+ shared|static|nostdlib|nodefaultlibs|nostartfiles:;:-fPIE -pie}"
+#else
+#define PIE_DRIVER_SELF_SPECS ""
+#endif
+
+#ifndef GNU_DRIVER_SELF_SPECS
+#define GNU_DRIVER_SELF_SPECS PIE_DRIVER_SELF_SPECS
+#endif
--- a/gcc/config/i386/gnu-user-common.h 2013-01-10 21:38:27.000000000 +0100
+++ b/gcc/config/i386/gnu-user-common.h 2013-10-23 17:37:45.432767049 +0200
@@ -70,3 +70,8 @@ along with GCC; see the file COPYING3.
/* Static stack checking is supported by means of probes. */
#define STACK_CHECK_STATIC_BUILTIN 1
+
+/* Use GNU_DRIVER_SELF_SPECS. */
+#ifndef DRIVER_SELF_SPECS
+#define DRIVER_SELF_SPECS GNU_DRIVER_SELF_SPECS
+#endif
--- a/gcc/configure.ac 2013-09-25 18:10:35.000000000 +0200
+++ b/gcc/configure.ac 2013-10-22 21:26:56.287602139 +0200
@@ -5434,6 +5434,30 @@ if test x"${LINKER_HASH_STYLE}" != x; th
[The linker hash style])
fi
+# Check whether --enable-default-pie was given and target have the support.
+AC_ARG_ENABLE(default-pie,
+[AS_HELP_STRING([--enable-default-pie],
+ [enable Position Independent Executable as default])],
+enable_default_pie=$enableval,
+enable_default_pie=no)
+if test x$enable_default_pie = xyes; then
+ AC_MSG_CHECKING(if $target supports default PIE)
+ enable_default_pie=no
+ case $target in
+ i?86*-*-linux* | x86_64*-*-linux*)
+ enable_default_pie=yes
+ ;;
+ *)
+ ;;
+ esac
+ AC_MSG_RESULT($enable_default_pie)
+fi
+if test x$enable_default_pie == xyes ; then
+ AC_DEFINE(ENABLE_DEFAULT_PIE, 1,
+ [Define if your target supports default PIE and it is enabled.])
+fi
+AC_SUBST([enable_default_pie])
+
# Configure the subdirectories
# AC_CONFIG_SUBDIRS($subdirs)
--- a/gcc/Makefile.in 2013-10-02 21:52:27.000000000 +0200
+++ b/gcc/Makefile.in 2013-10-24 17:46:22.055357122 +0200
@@ -957,14 +957,23 @@ CONTEXT_H = context.h
# cross compiler which does not use the native headers and libraries.
INTERNAL_CFLAGS = -DIN_GCC @CROSS@
+# We don't want to compile the compiler with -fPIE, it make PCH fail.
+enable_default_pie = @enable_default_pie@
+ifeq ($(enable_default_pie),yes)
+NOPIE_CFLAGS = -fno-PIE
+else
+NOPIE_CFLAGS=
+endif
+
# This is the variable actually used when we compile. If you change this,
# you probably want to update BUILD_CFLAGS in configure.ac
-ALL_CFLAGS = $(T_CFLAGS) $(CFLAGS-$@) \
+ALL_CFLAGS = $(NOPIE_CFLAGS) $(T_CFLAGS) $(CFLAGS-$@) \
$(CFLAGS) $(INTERNAL_CFLAGS) $(COVERAGE_FLAGS) $(WARN_CFLAGS) @DEFS@
# The C++ version.
-ALL_CXXFLAGS = $(T_CFLAGS) $(CFLAGS-$@) $(CXXFLAGS) $(INTERNAL_CFLAGS) \
- $(COVERAGE_FLAGS) $(NOEXCEPTION_FLAGS) $(WARN_CXXFLAGS) @DEFS@
+ALL_CXXFLAGS = $(NOPIE_CFLAGS) $(T_CFLAGS) $(CFLAGS-$@) $(CXXFLAGS) \
+ $(INTERNAL_CFLAGS) $(COVERAGE_FLAGS) $(NOEXCEPTION_FLAGS) \
+ $(WARN_CXXFLAGS) @DEFS@
# Likewise. Put INCLUDES at the beginning: this way, if some autoconf macro
# puts -I options in CPPFLAGS, our include files in the srcdir will always
@@ -1805,6 +1814,7 @@ libgcc.mvars: config.status Makefile spe
echo GCC_CFLAGS = '$(GCC_CFLAGS)' >> tmp-libgcc.mvars
echo INHIBIT_LIBC_CFLAGS = '$(INHIBIT_LIBC_CFLAGS)' >> tmp-libgcc.mvars
echo TARGET_SYSTEM_ROOT = '$(TARGET_SYSTEM_ROOT)' >> tmp-libgcc.mvars
+ echo enable_default_pie = '$(enable_default_pie)' >> tmp-libgcc.mvars
mv tmp-libgcc.mvars libgcc.mvars
@@ -3460,6 +3470,9 @@ site.exp: ./config.status Makefile
@if test "@enable_lto@" = "yes" ; then \
echo "set ENABLE_LTO 1" >> ./site.tmp; \
fi
+ @if test "@enable_default_pie@" = "yes" ; then \
+ echo "set ENABLE_DEFAULT_PIE 1" >> ./site.tmp; \
+ fi
# If newlib has been configured, we need to pass -B to gcc so it can find
# newlib's crt0.o if it exists. This will cause a "path prefix not used"
# message if it doesn't, but the testsuite is supposed to ignore the message -
--- a/libgcc/Makefile.in 2011-11-22 04:01:02.000000000 +0100
+++ b/libgcc/Makefile.in 2012-06-29 00:15:04.534016511 +0200
@@ -275,11 +275,17 @@ override CFLAGS := $(filter-out -fprofil
INTERNAL_CFLAGS = $(CFLAGS) $(LIBGCC2_CFLAGS) $(HOST_LIBGCC2_CFLAGS) \
$(INCLUDES) @set_have_cc_tls@ @set_use_emutls@
+#Don't use -fPIE when compiling crtbegin/end.
+ifeq ($(enable_default_pie),yes)
+NOPIE_CFLAGS = -fno-PIE
+else
+NOPIE_CFLAGS=
+endif
# Options to use when compiling crtbegin/end.
CRTSTUFF_CFLAGS = -O2 $(GCC_CFLAGS) $(INCLUDES) $(MULTILIB_CFLAGS) -g0 \
-finhibit-size-directive -fno-inline -fno-exceptions \
-fno-zero-initialized-in-bss -fno-toplevel-reorder -fno-tree-vectorize \
- -fno-stack-protector \
+ -fno-stack-protector $(NOPIE_CFLAGS) \
$(INHIBIT_LIBC_CFLAGS)
# Extra flags to use when compiling crt{begin,end}.o.
--- a/gcc/doc/install.texi 2013-10-01 19:29:40.000000000 +0200
+++ b/gcc/doc/install.texi 2013-11-17 16:13:20.474144921 +0100
@@ -1421,6 +1421,10 @@ do a @samp{make -C gcc gnatlib_and_tools
Specify that the run-time libraries for stack smashing protection
should not be built.
+@item --enable-default-pie
+Turn on @option{-fPIE} and @option{-pie} by default if supported.
+Currently supported targets are i?86-*-linux* and x86-64-*-linux*.
+
@item --disable-libquadmath
Specify that the GCC quad-precision math library should not be built.
On some systems, the library is required to be linkable when building
--- a/gcc/doc/invoke.texi 2013-10-03 19:13:50.000000000 +0200
+++ b/gcc/doc/invoke.texi 2013-11-17 21:30:02.784220111 +0100
@@ -10134,6 +10134,12 @@ For predictable results, you must also s
used for compilation (@option{-fpie}, @option{-fPIE},
or model suboptions) when you specify this linker option.
+NOTE: With configure --enable-default-pie this option is enabled by default
+for C, C++, ObjC, ObjC++, if none of @option{-fno-PIE}, @option{-fno-pie},
+@option{-fPIC}, @option{-fpic}, @option{-fno-PIC}, @option{-fno-pic},
+@option{-nostdlib}, @option{-nostartfiles}, @option{-shared},
+@option{-nodefaultlibs}, nor @option{static} are found.
+
@item -rdynamic
@opindex rdynamic
Pass the flag @option{-export-dynamic} to the ELF linker, on targets
@@ -21371,6 +21377,12 @@ used during linking.
@code{__pie__} and @code{__PIE__}. The macros have the value 1
for @option{-fpie} and 2 for @option{-fPIE}.
+NOTE: With configure --enable-default-pie this option is enabled by default
+for C, C++, ObjC, ObjC++, if none of @option{-fno-PIE}, @option{-fno-pie},
+@option{-fPIC}, @option{-fpic}, @option{-fno-PIC}, @option{-fno-pic},
+@option{-nostdlib}, @option{-nostartfiles}, @option{-shared},
+@option{-nodefaultlibs}, nor @option{static} are found.
+
@item -fno-jump-tables
@opindex fno-jump-tables
Do not use jump tables for switch statements even where it would be
