x86: Default to vsyscall=native for now
authorAdrian Bunk <bunk@stusta.de>
Wed, 5 Oct 2011 21:40:47 +0000 (00:40 +0300)
committerIngo Molnar <mingo@elte.hu>
Tue, 11 Oct 2011 06:23:34 +0000 (08:23 +0200)
commit2b666859ec323403ac9a3a441d16eab30945404b
treea2db4a7fc4cc386deda62584379713fa5a5d6bbb
parent65112dccf8a113737684366349d7f9ec373ddc47
x86: Default to vsyscall=native for now

This UML breakage:

  linux-2.6.30.1[3800] vsyscall fault (exploit attempt?) ip:ffffffffff600000 cs:33 sp:7fbfb9c498 ax:ffffffffff600000 si:0 di:606790
  linux-2.6.30.1[3856] vsyscall fault (exploit attempt?) ip:ffffffffff600000 cs:33 sp:7fbfb13168 ax:ffffffffff600000 si:0 di:606790

Is caused by commit 3ae36655 ("x86-64: Rework vsyscall emulation and add
vsyscall= parameter") - the vsyscall emulation code is not fully cooked
yet as UML relies on some rather fragile SIGSEGV semantics.

Linus suggested in https://lkml.org/lkml/2011/8/9/376 to default
to vsyscall=native for now, this patch implements that.

Signed-off-by: Adrian Bunk <bunk@kernel.org>
Acked-by: Andrew Lutomirski <luto@mit.edu>
Cc: H. Peter Anvin <hpa@linux.intel.com>
Link: http://lkml.kernel.org/r/20111005214047.GE14406@localhost.pp.htv.fi
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Documentation/kernel-parameters.txt
arch/x86/kernel/vsyscall_64.c