Re: [PATCH] [RESEND] i386 and x86_64: randomize brk()

[Andrew Morton <akpm@linux-foundation.org>]

On Tue, 11 Sep 2007 14:17:24 +0200 (CEST) Jiri Kosina <jkosina@suse.cz> wrote:

> i386 and x86_64: randomize brk()

I seem to have a different copy of this patch from the one which you
originally sent.  It's the one which implements arch_randomize_brk() in
each arch's header file.  Mayeb it wasn't cc'ed to a mailing list of maybe
I just lost the email, dunno.

Anyway, it breaks on ia64:

  CC      arch/ia64/ia32/binfmt_elf32.o
In file included from arch/ia64/ia32/binfmt_elf32.c:49:
arch/ia64/ia32/../../../fs/binfmt_elf.c: In function `load_elf_binary':
arch/ia64/ia32/../../../fs/binfmt_elf.c:1085: error: implicit declaration of function `arch_randomize_brk'
make[1]: *** [arch/ia64/ia32/binfmt_elf32.o] Error 1
make: *** [arch/ia64/ia32/binfmt_elf32.o] Error 2

This is because ia64 takes the exceptional stupidity which is our
elf-handling build system and adds an extra layer of stupidity on top of
it.  Look:

akpm2:/usr/src/25> head include/asm-ia64/elf.h
#ifndef _ASM_IA64_ELF_H
#define _ASM_IA64_ELF_H

/*
 * ELF-specific definitions.
 *
 * Copyright (C) 1998-1999, 2002-2004 Hewlett-Packard Co
 *      David Mosberger-Tang <davidm@hpl.hp.com>
 */

akpm2:/usr/src/25> grep -r _ASM_IA64_ELF_H arch/ia64
arch/ia64/ia32/ia32priv.h:#define _ASM_IA64_ELF_H               /* Don't include elf.h */

can you believe this stuff?

Anyway, I'm presently running with this loveliness:


--- a/include/asm-ia64/elf.h~i386-and-x86_64-randomize-brk-2-fix
+++ a/include/asm-ia64/elf.h
@@ -249,8 +249,10 @@ do {									\
 
 #endif /* __KERNEL__ */
 
+#endif /* _ASM_IA64_ELF_H */
+
+#ifndef IA64_IS_WEIRD
 static inline void arch_randomize_brk(void)
 {
 }
-
-#endif /* _ASM_IA64_ELF_H */
+#endif
_

Wanna see if there's something saner we can do please?