2005-01-21 Jakub Jelinek <jakub@redhat.com>

	[BZ #735]
	* elf/Makefile: Add rules to build and run tst-align2.
	* elf/tst-align2.c: New test.
	* elf/tst-alignmod2.c: New file.
	* sysdeps/powerpc/tst-stack-align.h: New file.
	* sysdeps/i386/dl-machine.h (RTLD_START): Align stack and clear frame
	pointer before calling _dl_init.
	* sysdeps/x86_64/dl-machine.h (RTLD_START): Likewise.

3 files changed, 67 insertions, 2 deletions

diff --git a/sysdeps/i386/dl-machine.h b/sysdeps/i386/dl-machine.h
index c48d9d325e..af7e3f1bba 100644
--- a/sysdeps/i386/dl-machine.h
+++ b/sysdeps/i386/dl-machine.h
@@ -308,11 +308,21 @@ _dl_start_user:\n\
 	movl _rtld_local@GOTOFF(%ebx), %eax\n\
 	leal 8(%esp,%edx,4), %esi\n\
 	leal 4(%esp), %ecx\n\
+	movl %esp, %ebp\n\
+	# Make sure _dl_init is run with 16 byte aligned stack.\n\
+	andl $-16, %esp\n\
+	pushl %eax\n\
+	pushl %eax\n\
+	pushl %ebp\n\
 	pushl %esi\n\
+	# Clear %ebp, so that even constructors have terminated backchain.\n\
+	xorl %ebp, %ebp\n\
 	# Call the function to run the initializers.\n\
 	call _dl_init_internal@PLT\n\
 	# Pass our finalizer function to the user in %edx, as per ELF ABI.\n\
 	leal _dl_fini@GOTOFF(%ebx), %edx\n\
+	# Restore %esp _start expects.\n\
+	movl (%esp), %esp\n\
 	# Jump to the user's entry point.\n\
 	jmp *%edi\n\
 	.previous\n\
diff --git a/sysdeps/powerpc/tst-stack-align.h b/sysdeps/powerpc/tst-stack-align.h
new file mode 100644
index 0000000000..99a0ffcef7
--- /dev/null
+++ b/sysdeps/powerpc/tst-stack-align.h
@@ -0,0 +1,47 @@
+/* Copyright (C) 2005 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
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+#include <stdio.h>
+#include <stdint.h>
+
+#define TEST_STACK_ALIGN() \
+  ({									     \
+    /* Altivec __vector int etc. needs 16byte aligned stack.		     \
+       Instead of using altivec.h here, use aligned attribute instead.  */   \
+    struct _S								     \
+      {									     \
+        int _i __attribute__((aligned (16)));				     \
+	int _j[3];							     \
+      } _s = { ._i = 18, ._j[0] = 19, ._j[1] = 20, ._j[2] = 21 };	     \
+    double _d = 12.0;							     \
+    long double _ld = 15.0;						     \
+    int _ret = 0;							     \
+    printf ("__vector int:  { %d, %d, %d, %d } %p %zu\n", _s._i, _s._j[0],   \
+            _s._j[1], _s._j[2], &_s, __alignof (_s));			     \
+    if ((((uintptr_t) &_s) & (__alignof (_s) - 1)) != 0)		     \
+      _ret = 1;								     \
+									     \
+    printf ("double:  %g %p %zu\n", _d, &_d, __alignof (double));	     \
+    if ((((uintptr_t) &_d) & (__alignof (double) - 1)) != 0)		     \
+      _ret = 1;								     \
+									     \
+    printf ("ldouble: %Lg %p %zu\n", _ld, &_ld, __alignof (long double));    \
+    if ((((uintptr_t) &_ld) & (__alignof (long double) - 1)) != 0)	     \
+      _ret = 1;								     \
+    _ret;								     \
+    })
diff --git a/sysdeps/x86_64/dl-machine.h b/sysdeps/x86_64/dl-machine.h
index b932f51d15..408438647d 100644
--- a/sysdeps/x86_64/dl-machine.h
+++ b/sysdeps/x86_64/dl-machine.h
@@ -280,16 +280,24 @@ _dl_start_user:\n\
 	# Call _dl_init (struct link_map *main_map, int argc, char **argv, char **env)\n\
 	# argc -> rsi\n\
 	movq %rdx, %rsi\n\
+	# Save %rsp value in %r13.\n\
+	movq %rsp, %r13\n\
+	# And align stack for the _dl_init_internal call. \n\
+	andq $-16, %rsp\n\
 	# _dl_loaded -> rdi\n\
 	movq _rtld_local(%rip), %rdi\n\
 	# env -> rcx\n\
-	leaq 16(%rsp,%rdx,8), %rcx\n\
+	leaq 16(%r13,%rdx,8), %rcx\n\
 	# argv -> rdx\n\
-	leaq 8(%rsp), %rdx\n\
+	leaq 8(%r13), %rdx\n\
+	# Clear %rbp to mark outermost frame obviously even for constructors.\n\
+	xorq %rbp, %rbp\n\
 	# Call the function to run the initializers.\n\
 	call _dl_init_internal@PLT\n\
 	# Pass our finalizer function to the user in %rdx, as per ELF ABI.\n\
 	leaq _dl_fini(%rip), %rdx\n\
+	# And make sure %rsp points to argc stored on the stack.\n\
+	movq %r13, %rsp\n\
 	# Jump to the user's entry point.\n\
 	jmp *%r12\n\
 .previous\n\