From: Anton Blanchard <anton@samba•org>
To: linuxppc-dev@ozlabs•org
Subject: [patch 05/10] powerpc: More stack randomisation for 64bit binaries
Date: Sun, 22 Feb 2009 22:50:02 +1100 [thread overview]
Message-ID: <20090222115332.289241697@samba.org> (raw)
In-Reply-To: 20090222114957.213647384@samba.org
At the moment we randomise the stack by 8MB on 32bit and 64bit tasks. Since we
have a lot more address space to play with on 64bit, lets do what x86 does and
increase that randomisation to 1GB:
before:
# for i in seq `1 10` ; do sleep 1 & cat /proc/${!}/maps | grep stack; done
fffffebc000-fffffed1000 rw-p ffffffeb000 00:00 0 [stack]
ffffff5a000-ffffff6f000 rw-p ffffffeb000 00:00 0 [stack]
fffffdb2000-fffffdc7000 rw-p ffffffeb000 00:00 0 [stack]
fffffd3e000-fffffd53000 rw-p ffffffeb000 00:00 0 [stack]
fffffad9000-fffffaee000 rw-p ffffffeb000 00:00 0 [stack]
after:
# for i in seq `1 10` ; do sleep 1 & cat /proc/${!}/maps | grep stack; done
ffff5c27000-ffff5c3c000 rw-p ffffffeb000 00:00 0 [stack]
fffebe5e000-fffebe73000 rw-p ffffffeb000 00:00 0 [stack]
fffcb298000-fffcb2ad000 rw-p ffffffeb000 00:00 0 [stack]
fffc719d000-fffc71b2000 rw-p ffffffeb000 00:00 0 [stack]
fffe01af000-fffe01c4000 rw-p ffffffeb000 00:00 0 [stack]
Signed-off-by: Anton Blanchard <anton@samba•org>
---
Index: linux-2.6/arch/powerpc/include/asm/elf.h
===================================================================
--- linux-2.6.orig/arch/powerpc/include/asm/elf.h 2009-02-20 13:39:05.000000000 +1100
+++ linux-2.6/arch/powerpc/include/asm/elf.h 2009-02-20 13:51:20.000000000 +1100
@@ -270,6 +270,11 @@
int uses_interp);
#define VDSO_AUX_ENT(a,b) NEW_AUX_ENT(a,b);
+/* 1GB for 64bit, 8MB for 32bit */
+#define STACK_RND_MASK (is_32bit_task() ? \
+ (0x7ff >> (PAGE_SHIFT - 12)) : \
+ (0x3ffff >> (PAGE_SHIFT - 12)))
+
#endif /* __KERNEL__ */
/*
--
next prev parent reply other threads:[~2009-02-22 11:50 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-02-22 11:49 [patch 00/10] PowerPC address space randomisation Anton Blanchard
2009-02-22 11:49 ` [patch 01/10] powerpc: Move is_32bit_task Anton Blanchard
2009-02-22 11:49 ` [patch 02/10] powerpc: Use new layout for 64bit binaries Anton Blanchard
2009-02-22 11:50 ` [patch 03/10] powerpc: Rearrange mmap.c Anton Blanchard
2009-02-22 11:50 ` [patch 04/10] powerpc: Randomise mmap start address Anton Blanchard
2009-02-22 11:50 ` Anton Blanchard [this message]
2009-02-22 11:50 ` [patch 06/10] powerpc: Randomise lower bits of stack address Anton Blanchard
2009-02-22 11:50 ` [patch 07/10] powerpc: Randomise the brk region Anton Blanchard
2009-02-22 11:50 ` [patch 08/10] powerpc: Ensure random space between stack and mmaps Anton Blanchard
2009-02-22 11:50 ` [patch 09/10] powerpc: Increase stack gap on 64bit binaries Anton Blanchard
2009-02-22 11:50 ` [patch 10/10] powerpc: Randomise PIEs Anton Blanchard
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20090222115332.289241697@samba.org \
--to=anton@samba$(echo .)org \
--cc=linuxppc-dev@ozlabs$(echo .)org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox