Re: [PATCH] Fix pr80044, -static and -pie insanity, and pr81170

["H.J. Lu" <hjl dot tools at gmail dot com>]

On Tue, Jul 18, 2017 at 10:11 PM, Alan Modra <amodra@gmail.com> wrote:
> On Tue, Jul 18, 2017 at 07:49:48AM -0700, H.J. Lu wrote:
>> The difference is with --enable-default-pie, the gcc driver doesn't pass
>> both -pie and -static ld when "-static -pie" is used.   Does your change
>> pass both -pie and -static ld when "-static -pie" is used?
>
> Again, as I said in the original post: "In both cases you now will
> have -static completely overriding -pie".
>
> That means "gcc -pie -static" and "gcc -static -pie" just pass
> "-static" to ld, and select the appropriate startup files for a static
> executable, when configured with --disable-default-pie.  Which is what
> happens currently for --enable-default-pie.
>
> None of this is rocket science.  I know what I'm doing where the
> linker and startup files are concerned, and I'm comfortable with the
> gcc specs language.  The patch is simple!  It should be easy to
> review, except for trying to understand the "-" lines.  Yet it has sat
> unreviewed for nearly four weeks.  And it fixes a powerpc
> --enable-default-pie bootstrap failure (pr81295).
>
> Joseph, would you please take a look?
> https://gcc.gnu.org/ml/gcc-patches/2017-06/msg01678.html
>
> I know there is more to do in this area, for example, it seems to me
> that the HAVE_LD_PIE definition of GNU_USER_TARGET_STARTFILE_SPEC is
> good for !HAVE_LD_PIE, and similarly for GNU_USE_TARGET_ENDFILE_SPEC.
> And yes, I propagated that duplication into rs6000/sysv4.h, which
> needs some serious tidying.  rs6000/sysv4.h linux support ought to be
> using the gnu-user.h defines rather than copying them, something I've
> told Segher I'll look at after this patch goes in.
>

Before your patch, I can creating static PIE when GCC is configured
with --disable-default-pie.  After your change,  both --enable-default-pie
and --disable-default-pie prevent creating static PIE.  I opened a bug
report for -static-pie:

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81498

This patch, which should be applied on top of your patch, adds support
for -static-pie.  Can we merge 2 patches into 1?

Thanks.

-- 
H.J.

From b65e6477a8c41c7c8b4602c22e92b7b8b10960ab Mon Sep 17 00:00:00 2001
From: "H.J. Lu" <hjl.tools@gmail.com>
Date: Thu, 20 Jul 2017 14:08:18 -0700
Subject: [PATCH] Add -static-pie to GCC driver for static PIE

A static position independent executable is similar to static executable,
but can be loaded at any address without a dynamic linker.  All linker
input files must be compiled with -fpie or -fPIE and linker must support
--no-dynamic-linker to avoid linking with dynamic linker.  "-z text" is
also passed to linker to prevent dynamic relocations in readonly segments.

	PR driver/81498
	* common.opt (-static-pie): New alias.
	(shared): Negate static-pie.
	(static-pie): New option.
	* config/gnu-user.h (GNU_USER_TARGET_STARTFILE_SPEC): Add
	-static-pie support.
	(GNU_USER_TARGET_ENDFILE_SPEC): Likewise.
	(LINK_GCC_C_SEQUENCE_SPEC): Likewise.
	* config/i386/gnu-user.h (GNU_USER_TARGET_LINK_SPEC): Likewise.
	* config/i386/gnu-user64.h (GNU_USER_TARGET_LINK_SPEC): Likewise.
	* gcc.c (init_gcc_specs): Likewise.
	* doc/invoke.texi: Document -static-pie.
---
 gcc/common.opt               |  9 ++++++++-
 gcc/config/gnu-user.h        | 13 +++++++------
 gcc/config/i386/gnu-user.h   |  7 ++++---
 gcc/config/i386/gnu-user64.h | 11 ++++++-----
 gcc/doc/invoke.texi          |  9 ++++++++-
 gcc/gcc.c                    |  6 +++---
 6 files changed, 36 insertions(+), 19 deletions(-)

diff --git a/gcc/common.opt b/gcc/common.opt
index e81165c488b..4ada85a65a0 100644
--- a/gcc/common.opt
+++ b/gcc/common.opt
@@ -346,6 +346,9 @@ Common Alias(pedantic-errors)
 -pie
 Driver Alias(pie)
 
+-static-pie
+Driver Alias(static-pie)
+
 -pipe
 Driver Alias(pipe)
 
@@ -3050,7 +3053,7 @@ x
 Driver Joined Separate
 
 shared
-Driver RejectNegative Negative(pie)
+Driver RejectNegative Negative(static-pie)
 Create a shared library.
 
 shared-libgcc
@@ -3102,6 +3105,10 @@ pie
 Driver RejectNegative Negative(no-pie)
 Create a position independent executable.
 
+static-pie
+Driver RejectNegative Negative(pie)
+Create a static position independent executable.
+
 z
 Driver Joined Separate
 
diff --git a/gcc/config/gnu-user.h b/gcc/config/gnu-user.h
index de605b0c466..f0cbde3343c 100644
--- a/gcc/config/gnu-user.h
+++ b/gcc/config/gnu-user.h
@@ -53,11 +53,11 @@ see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
   "%{shared:; \
      pg|p|profile:gcrt1.o%s; \
      static:crt1.o%s; \
-     " PIE_SPEC ":Scrt1.o%s; \
+     static-pie|" PIE_SPEC ":Scrt1.o%s; \
      :crt1.o%s} \
    crti.o%s \
    %{static:crtbeginT.o%s; \
-     shared|" PIE_SPEC ":crtbeginS.o%s; \
+     shared|static-pie|" PIE_SPEC ":crtbeginS.o%s; \
      :crtbegin.o%s} \
    %{fvtable-verify=none:%s; \
      fvtable-verify=preinit:vtv_start_preinit.o%s; \
@@ -70,7 +70,7 @@ see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
      :crt1.o%s} \
    crti.o%s \
    %{static:crtbeginT.o%s; \
-     shared|pie:crtbeginS.o%s; \
+     shared|pie|static-pie:crtbeginS.o%s; \
      :crtbegin.o%s} \
    %{fvtable-verify=none:%s; \
      fvtable-verify=preinit:vtv_start_preinit.o%s; \
@@ -92,7 +92,7 @@ see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
      fvtable-verify=preinit:vtv_end_preinit.o%s; \
      fvtable-verify=std:vtv_end.o%s} \
    %{static:crtend.o%s; \
-     shared|" PIE_SPEC ":crtendS.o%s; \
+     shared|static-pie|" PIE_SPEC ":crtendS.o%s; \
      :crtend.o%s} \
    crtn.o%s \
    " CRTOFFLOADEND
@@ -102,7 +102,7 @@ see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
      fvtable-verify=preinit:vtv_end_preinit.o%s; \
      fvtable-verify=std:vtv_end.o%s} \
    %{static:crtend.o%s; \
-     shared|pie:crtendS.o%s; \
+     shared|pie|static-pie:crtendS.o%s; \
      :crtend.o%s} \
    crtn.o%s \
    " CRTOFFLOADEND
@@ -137,7 +137,8 @@ see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
 
 #undef LINK_GCC_C_SEQUENCE_SPEC
 #define LINK_GCC_C_SEQUENCE_SPEC \
-  "%{static:--start-group} %G %L %{static:--end-group}%{!static:%G}"
+  "%{static|static-pie:--start-group} %G %L \
+   %{static|static-pie:--end-group}%{!static:%{!static-pie:%G}}"
 
 /* Use --as-needed -lgcc_s for eh support.  */
 #ifdef HAVE_LD_AS_NEEDED
diff --git a/gcc/config/i386/gnu-user.h b/gcc/config/i386/gnu-user.h
index a4c88f1a848..8983dc9ecd7 100644
--- a/gcc/config/i386/gnu-user.h
+++ b/gcc/config/i386/gnu-user.h
@@ -77,9 +77,10 @@ along with GCC; see the file COPYING3.  If not see
 #define GNU_USER_TARGET_LINK_SPEC "-m %(link_emulation) %{shared:-shared} \
   %{!shared: \
     %{!static: \
-      %{rdynamic:-export-dynamic} \
-      -dynamic-linker %(dynamic_linker)} \
-      %{static:-static}}"
+      %{!static-pie: \
+	%{rdynamic:-export-dynamic} \
+	-dynamic-linker %(dynamic_linker)}} \
+      %{static:-static} %{static-pie:-static -pie --no-dynamic-linker -z text}}"
 
 #undef	LINK_SPEC
 #define LINK_SPEC GNU_USER_TARGET_LINK_SPEC
diff --git a/gcc/config/i386/gnu-user64.h b/gcc/config/i386/gnu-user64.h
index 39f5ef6a68b..6fc9eae6f6b 100644
--- a/gcc/config/i386/gnu-user64.h
+++ b/gcc/config/i386/gnu-user64.h
@@ -59,11 +59,12 @@ see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
   %{shared:-shared} \
   %{!shared: \
     %{!static: \
-      %{rdynamic:-export-dynamic} \
-      %{" SPEC_32 ":-dynamic-linker " GNU_USER_DYNAMIC_LINKER32 "} \
-      %{" SPEC_64 ":-dynamic-linker " GNU_USER_DYNAMIC_LINKER64 "} \
-      %{" SPEC_X32 ":-dynamic-linker " GNU_USER_DYNAMIC_LINKERX32 "}} \
-    %{static:-static}}"
+      %{!static-static: \
+	%{rdynamic:-export-dynamic} \
+	%{" SPEC_32 ":-dynamic-linker " GNU_USER_DYNAMIC_LINKER32 "} \
+	%{" SPEC_64 ":-dynamic-linker " GNU_USER_DYNAMIC_LINKER64 "} \
+	%{" SPEC_X32 ":-dynamic-linker " GNU_USER_DYNAMIC_LINKERX32 "}}} \
+    %{static:-static} %{static-pie:-static -pie --no-dynamic-linker -z text}}"
 
 #undef	LINK_SPEC
 #define LINK_SPEC GNU_USER_TARGET_LINK_SPEC
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index dfde403cbf2..027d9a97d6b 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -496,7 +496,7 @@ Objective-C and Objective-C++ Dialects}.
 @xref{Link Options,,Options for Linking}.
 @gccoptlist{@var{object-file-name}  -fuse-ld=@var{linker}  -l@var{library} @gol
 -nostartfiles  -nodefaultlibs  -nostdlib  -pie  -pthread  -rdynamic @gol
--s  -static  -static-libgcc  -static-libstdc++ @gol
+-s  -static -static-pie -static-libgcc  -static-libstdc++ @gol
 -static-libasan  -static-libtsan  -static-liblsan  -static-libubsan @gol
 -static-libmpx  -static-libmpxwrappers @gol
 -shared  -shared-libgcc  -symbolic @gol
@@ -11746,6 +11746,13 @@ or model suboptions) when you specify this linker option.
 @opindex no-pie
 Don't produce a position independent executable.
 
+@item -static-pie
+@opindex static-pie
+Produce a static position independent executable on targets that support
+it.  For predictable results, you must also specify the same set of
+options used for compilation (@option{-fpie}, @option{-fPIE},
+or model suboptions) when you specify this linker option.
+
 @item -pthread
 @opindex pthread
 Link with the POSIX threads library.  This option is supported on 
diff --git a/gcc/gcc.c b/gcc/gcc.c
index 80a8b8b2bee..ffd6e42114e 100644
--- a/gcc/gcc.c
+++ b/gcc/gcc.c
@@ -1668,8 +1668,8 @@ init_gcc_specs (struct obstack *obstack, const char *shared_name,
 {
   char *buf;
 
-  buf = concat ("%{static|static-libgcc:", static_name, " ", eh_name, "}"
-		"%{!static:%{!static-libgcc:"
+  buf = concat ("%{static|static-libgcc|static-pie:", static_name, " ", eh_name, "}"
+		"%{!static:%{!static-libgcc:%{!static-pie:"
 #if USE_LD_AS_NEEDED
 		"%{!shared-libgcc:",
 		static_name, " " LD_AS_NEEDED_OPTION " ",
@@ -1677,7 +1677,7 @@ init_gcc_specs (struct obstack *obstack, const char *shared_name,
 		"}"
 		"%{shared-libgcc:",
 		shared_name, "%{!shared: ", static_name, "}"
-		"}"
+		"}" "}"
 #else
 		"%{!shared:"
 		"%{!shared-libgcc:", static_name, " ", eh_name, "}"
-- 
2.13.3