We can't safely directly access an compat_alloc_user_space() pointer
with the siginfo copy functions. Bounce it through the stack.
Noticed by Al Viro using sparse
[ This was only added post 2.6.17, not in any released kernel ]
Cc: Al Viro <viro@ftp.linux.org.uk>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>