tree b8e4d369cadad21f33b7a5f7f69d43665f821ddc
parent 9b064fc3f95a8e44e929fdf4d6037334ea03d15b
author Al Viro <viro@zeniv.linux.org.uk> 1355512187 -0500
committer Al Viro <viro@zeniv.linux.org.uk> 1355958460 -0500

introduce generic sys_sigaltstack(), switch x86 and um to it

Conditional on CONFIG_GENERIC_SIGALTSTACK; architectures that do not
select it are completely unaffected

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>