Properly support -fPIE by linking PIE binaries with specially-built

Scrt1.o instead of crt1.o, since the later is built as non-PIC.

Separate i386-elf crt1.c into the pure assembler part and C code,
supplying all data extracted by assembler stub as explicit parameters [1].
Hide and localize _start1 symbol used as an interface between asm and
C code.

In collaboration with:	kan
Inspired by:	PR i386/127387 [1]
Prodded and tested by:	rdivacky [1]
MFC after:	3 weeks

contrib/gcc/config/freebsd-spec.h

@@ -103,9 +103,10 @@ Boston, MA 02110-1301, USA.  */
       %{p:gcrt1.o%s} \
       %{!p: \
 	%{profile:gcrt1.o%s} \
-	%{!profile:crt1.o%s}}}} \
+	%{!profile: \
+          %{pie: Scrt1.o%s;:crt1.o%s}}}}} \
   crti.o%s \
-  %{static:crtbeginT.o%s;shared:crtbeginS.o%s;:crtbegin.o%s}"
+  %{static:crtbeginT.o%s;shared|pie:crtbeginS.o%s;:crtbegin.o%s}"
 
 /* Provide an ENDFILE_SPEC appropriate for FreeBSD/i386.  Here we tack on
    our own magical crtend.o file (see crtstuff.c) which provides part of
@@ -113,8 +114,7 @@ Boston, MA 02110-1301, USA.  */
    entering `main', followed by the normal "finalizer" file, `crtn.o'.  */
 
 #define FBSD_ENDFILE_SPEC "\
-  %{!shared:crtend.o%s} \
-  %{shared:crtendS.o%s} \
+  %{shared|pie:crtendS.o%s;:crtend.o%s} \
   crtn.o%s "
 
 /* Provide a LIB_SPEC appropriate for FreeBSD as configured and as

lib/csu/amd64/Makefile

@@ -4,7 +4,7 @@
 
 SRCS=		crt1.c crti.S crtn.S
 OBJS=		${SRCS:N*.h:R:S/$/.o/g}
-OBJS+=		gcrt1.o
+OBJS+=		Scrt1.o gcrt1.o
 CFLAGS+=	-I${.CURDIR}/../common \
 		-I${.CURDIR}/../../libc/include
 CFLAGS+=	-fno-omit-frame-pointer
@@ -16,6 +16,9 @@ CLEANFILES=	${OBJS}
 gcrt1.o: crt1.c
 	${CC} ${CFLAGS} -DGCRT -c -o gcrt1.o ${.CURDIR}/crt1.c
 
+Scrt1.o: crt1.c
+	${CC} ${CFLAGS} -fPIC -DPIC -c -o Scrt1.o ${.CURDIR}/crt1.c
+
 realinstall:
 	${INSTALL} -o ${LIBOWN} -g ${LIBGRP} -m ${LIBMODE} \
 	    ${OBJS} ${DESTDIR}${LIBDIR}

lib/csu/arm/Makefile

@@ -4,7 +4,7 @@
 
 SRCS=		crt1.c crti.S crtn.S
 OBJS=		${SRCS:N*.h:R:S/$/.o/g}
-OBJS+=		gcrt1.o
+OBJS+=		Scrt1.o gcrt1.o
 CFLAGS+=	-Wall -Wno-unused \
 		-I${.CURDIR}/../common \
 		-I${.CURDIR}/../../libc/include
@@ -16,6 +16,9 @@ CLEANFILES=	${OBJS}
 gcrt1.o: crt1.c
 	${CC} ${CFLAGS} -DGCRT -c -o gcrt1.o ${.ALLSRC}
 
+Scrt1.o: crt1.c
+	${CC} ${CFLAGS} -fPIC -DPIC -c -o Scrt1.o ${.ALLSRC}
+
 realinstall:
 	${INSTALL} -o ${LIBOWN} -g ${LIBGRP} -m ${LIBMODE} \
 	    ${OBJS} ${DESTDIR}${LIBDIR}

lib/csu/i386-elf/Makefile

@@ -2,8 +2,8 @@
 
 .PATH: ${.CURDIR}/../common
 
-SRCS=		crt1.c crti.S crtn.S
-FILES=		${SRCS:N*.h:R:S/$/.o/g} gcrt1.o
+SRCS=		crti.S crtn.S
+FILES=		${SRCS:N*.h:R:S/$/.o/g} gcrt1.o crt1.o Scrt1.o
 FILESOWN=	${LIBOWN}
 FILESGRP=	${LIBGRP}
 FILESMODE=	${LIBMODE}
@@ -11,9 +11,23 @@ FILESDIR=	${LIBDIR}
 WARNS?=		6
 CFLAGS+=	-I${.CURDIR}/../common \
 		-I${.CURDIR}/../../libc/include
-CLEANFILES=	${FILES}
+CLEANFILES=	${FILES} crt1_c.o crt1_s.o gcrt1_c.o Scrt1_c.o
 
-gcrt1.o: crt1.c
-	${CC} ${CFLAGS} -DGCRT -c -o gcrt1.o ${.CURDIR}/crt1.c
+gcrt1_c.o: crt1_c.c
+	${CC} ${CFLAGS} -DGCRT -c -o gcrt1_c.o ${.CURDIR}/crt1_c.c
+
+gcrt1.o: gcrt1_c.o crt1_s.o
+	${LD} ${LDFLAGS} -o gcrt1.o -r crt1_s.o gcrt1_c.o
+
+crt1.o:	crt1_c.o crt1_s.o
+	${LD} ${LDFLAGS} -o crt1.o -r crt1_s.o crt1_c.o
+	objcopy --localize-symbol _start1 crt1.o
+
+Scrt1_c.o:	crt1_c.c
+	${CC} ${CFLAGS} -DGCRT -fPIC -DPIC -c -o Scrt1_c.o ${.CURDIR}/crt1_c.c
+
+Scrt1.o: Scrt1_c.o crt1_s.o
+	${LD} ${LDFLAGS} -o Scrt1.o -r crt1_s.o Scrt1_c.o
+	objcopy --localize-symbol _start1 Scrt1.o
 
 .include <bsd.prog.mk>

lib/csu/i386-elf/crt1_c.c

@@ -22,6 +22,8 @@
  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * $FreeBSD$
  */
 
 #ifndef lint
@@ -55,35 +57,15 @@ extern int etext;
 char **environ;
 const char *__progname = "";
 
-static __inline fptr
-get_rtld_cleanup(void)
-{
-	fptr retval;
+void _start1(fptr, int, char *[]) __dead2;
 
-#ifdef	__GNUC__
-	__asm__("movl %%edx,%0" : "=rm"(retval));
-#else
-	retval = (fptr)0; /* XXXX Fix this for other compilers */
-#endif
-	return(retval);
-}
-
-/* The entry function. */
+/* The entry function, C part. */
 void
-_start(char *ap, ...)
+_start1(fptr cleanup, int argc, char *argv[])
 {
-	fptr cleanup;
-	int argc;
-	char **argv;
 	char **env;
 	const char *s;
 
-#ifdef __GNUC__
-	__asm__("and $0xfffffff0,%esp");
-#endif
-	cleanup = get_rtld_cleanup();
-	argv = ≈
-	argc = *(long *)(void *)(argv - 1);
 	env = argv + argc + 1;
 	environ = env;
 	if (argc > 0 && argv[0] != NULL) {
@@ -110,4 +92,4 @@ __asm__("eprol:");
 	exit( main(argc, argv, env) );
 }
 
-__asm__(".ident\t\"$FreeBSD$\"");
+__asm(".hidden	_start1");

lib/csu/i386-elf/crt1_s.S

@@ -0,0 +1,44 @@
+/*-
+ * Copyright 2009 Konstantin Belousov.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * $FreeBSD$
+ */
+
+
+	.text
+	.align	4
+	.globl	_start
+	.type	_start, @function
+_start:	xorl	%ebp,%ebp
+	pushl	%ebp
+	movl	%esp,%ebp
+	andl	$0xfffffff0,%esp # align stack
+	leal	8(%ebp),%eax
+	pushl	%eax		# argv
+	pushl	4(%ebp)		# argc
+	pushl	%edx		# rtld cleanup
+	call	_start1
+	.size	_start, . - _start
+
+	.ident	"$FreeBSD$"

lib/csu/ia64/Makefile

@@ -4,7 +4,7 @@
 
 SRCS=		crt1.S crti.S crtn.S
 OBJS=		${SRCS:N*.h:R:S/$/.o/g}
-OBJS+=		gcrt1.o
+OBJS+=		Scrt1.o gcrt1.o
 CFLAGS+=	-Wall -Wno-unused \
 		-I${.CURDIR}/../common \
 		-I${.CURDIR}/../../libc/include
@@ -16,6 +16,9 @@ CLEANFILES=	${OBJS}
 gcrt1.o: crt1.S
 	${CC} ${CFLAGS} -DGCRT -c -o gcrt1.o ${.ALLSRC}
 
+Scrt1.o: crt1.S
+	${CC} ${CFLAGS} -fPIC -DPIC -c -o Scrt1.o ${.ALLSRC}
+
 realinstall:
 	${INSTALL} -o ${LIBOWN} -g ${LIBGRP} -m ${LIBMODE} \
 	    ${OBJS} ${DESTDIR}${LIBDIR}

lib/csu/mips/Makefile

@@ -4,7 +4,7 @@
 
 SRCS=		crt1.c crti.S crtn.S
 OBJS=		${SRCS:N*.h:R:S/$/.o/g}
-OBJS+=		gcrt1.o
+OBJS+=		Scrt1.o gcrt1.o
 CFLAGS+=	-Wall -Wno-unused \
 		-I${.CURDIR}/../common \
 		-I${.CURDIR}/../../libc/include
@@ -16,6 +16,9 @@ CLEANFILES=	${OBJS}
 gcrt1.o: crt1.c
 	${CC} ${CFLAGS} -DGCRT -c -o gcrt1.o ${.ALLSRC}
 
+Scrt1.o: crt1.c
+	${CC} ${CFLAGS} -fPIC -DPIC -c -o Scrt1.o ${.ALLSRC}
+
 realinstall:
 	${INSTALL} -o ${LIBOWN} -g ${LIBGRP} -m ${LIBMODE} \
 	    ${OBJS} ${DESTDIR}${LIBDIR}

lib/csu/powerpc/Makefile

@@ -4,7 +4,7 @@
 
 SRCS=		crt1.c crti.S crtn.S
 OBJS=		${SRCS:N*.h:R:S/$/.o/g}
-OBJS+=		gcrt1.o
+OBJS+=		Scrt1.o gcrt1.o
 CFLAGS+=	-Wall -Wno-unused \
 		-I${.CURDIR}/../common \
 		-I${.CURDIR}/../../libc/include
@@ -16,6 +16,9 @@ CLEANFILES=	${OBJS}
 gcrt1.o: crt1.c
 	${CC} ${CFLAGS} -DGCRT -c -o gcrt1.o ${.ALLSRC}
 
+Scrt1.o: crt1.c
+	${CC} ${CFLAGS} -fPIC -DPIC -c -o Scrt1.o ${.ALLSRC}
+
 realinstall:
 	${INSTALL} -o ${LIBOWN} -g ${LIBGRP} -m ${LIBMODE} \
 	    ${OBJS} ${DESTDIR}${LIBDIR}

lib/csu/sparc64/Makefile

@@ -4,7 +4,7 @@
 
 SRCS=		crt1.c crti.S crtn.S
 OBJS=		${SRCS:N*.h:R:S/$/.o/g}
-OBJS+=		gcrt1.o
+OBJS+=		Scrt1.o gcrt1.o
 CFLAGS+=	-I${.CURDIR}/../common -I${.CURDIR}/../../libc/include
 
 all: ${OBJS}
@@ -14,6 +14,9 @@ CLEANFILES=	${OBJS}
 gcrt1.o: crt1.c
 	${CC} ${CFLAGS} -DGCRT -c -o gcrt1.o ${.ALLSRC}
 
+Scrt1.o: crt1.c
+	${CC} ${CFLAGS} -fPIC -DPIC -c -o Scrt1.o ${.ALLSRC}
+
 realinstall:
 	${INSTALL} -o ${LIBOWN} -g ${LIBGRP} -m ${LIBMODE} \
 	    ${OBJS} ${DESTDIR}${LIBDIR}