WSL2-Linux-Kernel/fs/proc
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.

[akpm@osdl.org: cleanups]
[akpm@osdl.org: compile fix]
[akpm@osdl.org: compile fix 2]
[akpm@osdl.org: compile fix 3]
[akpm@osdl.org: revernt MAXMEM change]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Arjan van de Ven <arjan@infradead.org>
Cc: Gerd Hoffmann <kraxel@suse.de>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Zachary Amsden <zach@vmware.com>
Cc: Andi Kleen <ak@muc.de>
Cc: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 17:32:38 -07:00
..
Makefile [PATCH] kdump: Access dump file in elf format (/proc/vmcore) 2005-06-25 16:24:53 -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 Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
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
mmu.c [PATCH] fix impossible VmallocChunk 2005-05-17 07:59:10 -07:00
nommu.c [PATCH] output of /proc/maps on nommu systems is incomplete 2005-10-17 17:03:57 -07:00
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 Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
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