Ingo Molnar e6e5494cb2 [PATCH] vdso: randomize the i386 vDSO by moving it into a vma ...

Move the i386 VDSO down into a vma and thus randomize it.

Besides the security implications, this feature also helps debuggers, which
can COW a vma-backed VDSO just like a normal DSO and can thus do
single-stepping and other debugging features.

It's good for hypervisors (Xen, VMWare) too, which typically live in the same
high-mapped address space as the VDSO, hence whenever the VDSO is used, they
get lots of guest pagefaults and have to fix such guest accesses up - which
slows things down instead of speeding things up (the primary purpose of the
VDSO).

There's a new CONFIG_COMPAT_VDSO (default=y) option, which provides support
for older glibcs that still rely on a prelinked high-mapped VDSO.  Newer
distributions (using glibc 2.3.3 or later) can turn this option off.  Turning
it off is also recommended for security reasons: attackers cannot use the
predictable high-mapped VDSO page as syscall trampoline anymore.

There is a new vdso=[0|1] boot option as well, and a runtime
/proc/sys/vm/vdso_enabled sysctl switch, that allows the VDSO to be turned
on/off.

(This version of the VDSO-randomization patch also has working ELF
coredumping, the previous patch crashed in the coredumping code.)

This code is a combined work of the exec-shield VDSO randomization
code and Gerd Hoffmann's hypervisor-centric VDSO patch. Rusty Russell
started this patch and i completed it.

[[email protected]: cleanups]
[[email protected]: compile fix]
[[email protected]: compile fix 2]
[[email protected]: compile fix 3]
[[email protected]: revernt MAXMEM change]
Signed-off-by: Ingo Molnar <[email protected]>
Signed-off-by: Arjan van de Ven <[email protected]>
Cc: Gerd Hoffmann <[email protected]>
Cc: Rusty Russell <[email protected]>
Cc: Zachary Amsden <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: Jan Beulich <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

2006-06-27 17:32:38 -07:00

..

array.c

[PATCH] hrtimers: remove it_real_value calculation from proc/*/stat

2006-03-26 08:57:02 -08:00

base.c

[PATCH] SELinux: Add sockcreate node to procattr API

2006-06-26 09:58:26 -07:00

generic.c

[PATCH] mark f_ops const in the inode

2006-03-28 09:16:05 -08:00

inode-alloc.txt

…

inode.c

[PATCH] proc: Use struct pid not struct task_ref

2006-06-26 09:58:26 -07:00

internal.h

[PATCH] proc: Use struct pid not struct task_ref

2006-06-26 09:58:26 -07:00

kcore.c

[PATCH] Make most file operations structs in fs/ const

2006-03-28 09:16:06 -08:00

kmsg.c

[PATCH] Make most file operations structs in fs/ const

2006-03-28 09:16:06 -08:00

Makefile

…

mmu.c

…

nommu.c

…

proc_devtree.c

[PATCH] powerpc: Cope with duplicate node & property names in /proc/device-tree

2006-03-28 16:45:23 +11:00

proc_misc.c

[PATCH] Simplify proc/devices and fix early termination regression

2006-03-31 12:18:53 -08:00

proc_tty.c

…

root.c

[PATCH] VFS: Permit filesystem to override root dentry on mount

2006-06-23 07:42:45 -07:00

task_mmu.c

[PATCH] vdso: randomize the i386 vDSO by moving it into a vma

2006-06-27 17:32:38 -07:00

task_nommu.c

[PATCH] proc: Move proc_maps_operations into task_mmu.c

2006-06-26 09:58:24 -07:00

vmcore.c

[PATCH] kdump proc vmcore size oveflow fix

2006-04-11 06:18:42 -07:00