tree 10f3e3009387881a3c4a209b9d72c453aae865a1
parent 2b067fc9dd143be5e0ee94bae0fbd28ea0a407f8
author Al Viro <viro@zeniv.linux.org.uk> 1350537118 -0400
committer Al Viro <viro@zeniv.linux.org.uk> 1354157343 -0500

alpha: simplify fork and friends

* no need to restore everything from switch_stack when we only need $26
* no need to pass current_pt_regs() manually, we can just as easily
calculate it in alpha_clone/alpha_vfork ($8 + constant)
* interpretation of zero usp as "use the parent's" is simpler in copy_thread();
let fork and vfork just pass 0.

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