[PATCH] Allow main to come from a shared library for PIE [BZ #262]
Jakub Jelinek
jakub@redhat.com
Thu Jul 15 12:48:00 GMT 2004
Hi!
2004-07-15 Jakub Jelinek <jakub@redhat.com>
[BZ #262]
* sysdeps/i386/elf/start.S (_start): Use @GOT instead of @GOTOFF
for main. Patch by Solar Designer <solar@openwall.com>.
* elf/Makefile: Add rules to build and run tst-pie1.
* elf/tst-pie1.c: New test.
* elf/tst-piemod1.c: New file.
--- libc/sysdeps/i386/elf/start.S.jj 2004-07-15 14:41:46.000000000 +0200
+++ libc/sysdeps/i386/elf/start.S 2004-07-15 14:42:37.000000000 +0200
@@ -1,5 +1,6 @@
/* Startup code compliant to the ELF i386 ABI.
- Copyright (C) 1995-1998,2000,2001,2002,2003 Free Software Foundation, Inc.
+ Copyright (C) 1995, 1996, 1997, 1998, 2000, 2001, 2002, 2003, 2004
+ Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
@@ -81,8 +82,7 @@ _start:
pushl %ecx /* Push second argument: argv. */
pushl %esi /* Push first argument: argc. */
- leal BP_SYM (main)@GOTOFF(%ebx), %eax
- pushl %eax
+ pushl BP_SYM (main)@GOT(%ebx)
/* Call the user's main function, and exit with its value.
But let the libc call main. */
--- libc/elf/tst-pie1.c.jj 2004-07-15 14:37:41.000000000 +0200
+++ libc/elf/tst-pie1.c 2004-07-15 14:37:41.000000000 +0200
@@ -0,0 +1,5 @@
+int
+foo (void)
+{
+ return 34;
+}
--- libc/elf/Makefile.jj 2004-06-17 17:08:46.000000000 +0200
+++ libc/elf/Makefile 2004-07-15 14:47:43.000000000 +0200
@@ -80,7 +80,7 @@ distribute := rtld-Rules \
nodel2mod1.c nodel2mod2.c nodel2mod3.c \
reldep9.c reldep9mod1.c reldep9mod2.c reldep9mod3.c \
tst-array1.exp tst-array2.exp tst-array4.exp \
- tst-array2dep.c \
+ tst-array2dep.c tst-piemod1.c \
tst-execstack-mod.c tst-dlmodcount.c \
check-textrel.c dl-sysdep.h
@@ -160,6 +160,9 @@ tests-nodelete-yes = nodelete nodelete2
tests-nodlopen-yes = nodlopen nodlopen2
tests-execstack-yes = tst-execstack tst-execstack-needed tst-execstack-prog
endif
+ifeq (yesyes,$(have-fpie)$(build-shared))
+tests: $(objpfx)tst-pie1.out
+endif
modules-names = testobj1 testobj2 testobj3 testobj4 testobj5 testobj6 \
testobj1_1 failobj constload2 constload3 unloadmod \
dep1 dep2 dep3 dep4 $(modules-vis-$(have-protected)) \
@@ -185,6 +188,9 @@ modules-names = testobj1 testobj2 testob
ifeq (yes,$(have-initfini-array))
modules-names += tst-array2dep
endif
+ifeq (yesyes,$(have-fpie)$(build-shared))
+modules-names += tst-piemod1
+endif
modules-vis-yes = vismod1 vismod2 vismod3
modules-nodelete-yes = nodelmod1 nodelmod2 nodelmod3 nodelmod4 \
nodel2mod1 nodel2mod2 nodel2mod3
@@ -705,6 +711,25 @@ $(objpfx)tst-array4.out: $(objpfx)tst-ar
$< > $@
cmp $@ tst-array4.exp > /dev/null
+ifeq (yesyes,$(have-fpie)$(build-shared))
+CFLAGS-tst-pie1.c += -fpie
+
+$(objpfx)tst-pie1.out: $(objpfx)tst-pie1
+ $(elf-objpfx)$(rtld-installed-name) \
+ --library-path $(rpath-link)$(patsubst %,:%,$(sysdep-library-path)) \
+ $< > $@
+
+$(objpfx)tst-pie1: $(objpfx)tst-pie1.o $(objpfx)tst-piemod1.so
+ $(LINK.o) -pie -Wl,-O1 \
+ $(sysdep-LDFLAGS) $(config-LDFLAGS) \
+ $(extra-B-$(@F:lib%.so=%).so) -B$(csu-objpfx) \
+ $(extra-B-$(@F:lib%.so=%).so) $(load-map-file) \
+ $(LDFLAGS) $(LDFLAGS-$(@F)) \
+ -L$(subst :, -L,$(rpath-link)) -Wl,-rpath-link=$(rpath-link) \
+ -o $@ $(objpfx)tst-pie1.o $(objpfx)tst-piemod1.so \
+ $(common-objpfx)libc_nonshared.a
+endif
+
check-textrel-CFLAGS = -O -Wall -D_XOPEN_SOURCE=600 -D_BSD_SOURCE
$(objpfx)check-textrel: check-textrel.c
$(native-compile)
--- libc/elf/tst-piemod1.c.jj 2004-07-15 14:37:41.000000000 +0200
+++ libc/elf/tst-piemod1.c 2004-07-15 14:37:41.000000000 +0200
@@ -0,0 +1,20 @@
+#include <stdio.h>
+
+int
+foo (void)
+{
+ return 21;
+}
+
+int
+main (void)
+{
+ int val = foo ();
+ if (val != 34)
+ {
+ printf ("foo () returned %d\n", val);
+ return 1;
+ }
+
+ return 0;
+}
Jakub
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