arch/tile: eliminate pt_regs trampolines for syscalls

Using the new current_pt_regs() model, we can remove some trampolines
from assembly code and call directly to the C syscall implementations.
rt_sigreturn() and clone() still need some assembly wrapping, but no
longer are passed a pt_regs pointer.  sigaltstack() and the
tilepro-specific cmpxchg_badaddr() syscalls are now just straight C.

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>

1 files changed, 5 insertions, 4 deletions

diff --git a/arch/tile/kernel/signal.c b/arch/tile/kernel/signal.c
index 67efb656d104..657a7ace4ab4 100644
--- a/arch/tile/kernel/signal.c
+++ b/arch/tile/kernel/signal.c
@@ -37,10 +37,10 @@
 
 #define DEBUG_SIG 0
 
-SYSCALL_DEFINE3(sigaltstack, const stack_t __user *, uss,
-                stack_t __user *, uoss, struct pt_regs *, regs)
+SYSCALL_DEFINE2(sigaltstack, const stack_t __user *, uss,
+                stack_t __user *, uoss)
 {
-        return do_sigaltstack(uss, uoss, regs->sp);
+        return do_sigaltstack(uss, uoss, current_pt_regs()->sp);
 }
 
 
@@ -83,8 +83,9 @@ void signal_fault(const char *type, struct pt_regs *regs,
 }
 
 /* The assembly shim for this function arranges to ignore the return value. */
-SYSCALL_DEFINE1(rt_sigreturn, struct pt_regs *, regs)
+SYSCALL_DEFINE0(rt_sigreturn)
 {
+        struct pt_regs *regs = current_pt_regs();
         struct rt_sigframe __user *frame =
                 (struct rt_sigframe __user *)(regs->sp);
         sigset_t set;