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>
diff --git a/arch/alpha/kernel/process.c b/arch/alpha/kernel/process.c
index 51987dc..ad86c09 100644
--- a/arch/alpha/kernel/process.c
+++ b/arch/alpha/kernel/process.c
@@ -246,19 +246,17 @@
int
alpha_clone(unsigned long clone_flags, unsigned long usp,
int __user *parent_tid, int __user *child_tid,
- unsigned long tls_value, struct pt_regs *regs)
+ unsigned long tls_value)
{
- if (!usp)
- usp = rdusp();
-
- return do_fork(clone_flags, usp, regs, 0, parent_tid, child_tid);
+ return do_fork(clone_flags, usp, current_pt_regs(), 0,
+ parent_tid, child_tid);
}
int
-alpha_vfork(struct pt_regs *regs)
+alpha_vfork(void)
{
- return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, rdusp(),
- regs, 0, NULL, NULL);
+ return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, 0,
+ current_pt_regs(), 0, NULL, NULL);
}
/*
@@ -301,7 +299,7 @@
stack = ((struct switch_stack *) regs) - 1;
*childstack = *stack;
childstack->r26 = (unsigned long) ret_from_fork;
- childti->pcb.usp = usp;
+ childti->pcb.usp = usp ?: rdusp();
childti->pcb.ksp = (unsigned long) childstack;
childti->pcb.flags = 1; /* set FEN, clear everything else */