tree 7a33d918e4d35b0444820595cb2aaaae1f1f5bfa
parent 31fe4d331729e9687db84521c3ceb8e43390efcf
author Andi Kleen <ak@suse.de> 1142203979 +0100
committer Linus Torvalds <torvalds@g5.osdl.org> 1142232989 -0800

[PATCH] x86-64: Fix up handling of non canonical user RIPs

EM64T CPUs have somewhat weird error reporting for non canonical RIPs in
SYSRET.

We can't handle any exceptions there because the exception handler would
end up running on the user stack which is unsafe.

To avoid problems any code that might end up with a user touched pt_regs
should return using int_ret_from_syscall.  int_ret_from_syscall ends up
using IRET, which allows safe exceptions.

Cc: Ernie Petrides <petrides@redhat.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>