alpha: convert to generic sys_ptrace

This patch converts alpha to the generic sys_ptrace.  We use
force_successful_syscall_return to avoid having to pass the pt_regs pointer
down to the function.  I think the removal of the assemly stub is correct,
but I could only compile-test this patch, so please give it a spin before
commiting :)

Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

3 files changed, 6 insertions, 47 deletions

diff --git a/arch/alpha/kernel/entry.S b/arch/alpha/kernel/entry.S
index debc8f03886c..5fc61e281ac7 100644
--- a/arch/alpha/kernel/entry.S
+++ b/arch/alpha/kernel/entry.S
@@ -917,15 +917,6 @@ sys_pipe:
 .end sys_pipe
 
         .align  4
-        .globl  sys_ptrace
-        .ent    sys_ptrace
-sys_ptrace:
-        .prologue 0
-        mov     $sp, $20
-        jmp     $31, do_sys_ptrace
-.end sys_ptrace
-
-        .align  4
         .globl  sys_execve
         .ent    sys_execve
 sys_execve:
diff --git a/arch/alpha/kernel/ptrace.c b/arch/alpha/kernel/ptrace.c
index eaf4ee5f0c35..1e9ad52c460e 100644
--- a/arch/alpha/kernel/ptrace.c
+++ b/arch/alpha/kernel/ptrace.c
@@ -260,38 +260,12 @@ void ptrace_disable(struct task_struct *child)
         ptrace_cancel_bpt(child);
 }
 
-asmlinkage long
-do_sys_ptrace(long request, long pid, long addr, long data,
-              struct pt_regs *regs)
+long arch_ptrace(struct task_struct *child, long request, long addr, long data)
 {
-        struct task_struct *child;
         unsigned long tmp;
         size_t copied;
         long ret;
 
-        lock_kernel();
-        DBG(DBG_MEM, ("request=%ld pid=%ld addr=0x%lx data=0x%lx\n",
-                      request, pid, addr, data));
-        if (request == PTRACE_TRACEME) {
-                ret = ptrace_traceme();
-                goto out_notsk;
-        }
-
-        child = ptrace_get_task_struct(pid);
-        if (IS_ERR(child)) {
-                ret = PTR_ERR(child);
-                goto out_notsk;
-        }
-
-        if (request == PTRACE_ATTACH) {
-                ret = ptrace_attach(child);
-                goto out;
-        }
-
-        ret = ptrace_check_attach(child, request == PTRACE_KILL);
-        if (ret < 0)
-                goto out;
-
         switch (request) {
         /* When I and D space are separate, these will need to be fixed.  */
         case PTRACE_PEEKTEXT: /* read word at location addr. */
@@ -301,13 +275,13 @@ do_sys_ptrace(long request, long pid, long addr, long data,
                 if (copied != sizeof(tmp))
                         break;
                 
-                regs->r0 = 0;   /* special return: no errors */
+                force_successful_syscall_return();
                 ret = tmp;
                 break;
 
         /* Read register number ADDR. */
         case PTRACE_PEEKUSR:
-                regs->r0 = 0;   /* special return: no errors */
+                force_successful_syscall_return();
                 ret = get_reg(child, addr);
                 DBG(DBG_MEM, ("peek $%ld->%#lx\n", addr, ret));
                 break;
@@ -353,7 +327,7 @@ do_sys_ptrace(long request, long pid, long addr, long data,
                 /* make sure single-step breakpoint is gone. */
                 ptrace_cancel_bpt(child);
                 wake_up_process(child);
-                goto out;
+                break;
 
         case PTRACE_SINGLESTEP:  /* execute single instruction. */
                 ret = -EIO;
@@ -366,16 +340,12 @@ do_sys_ptrace(long request, long pid, long addr, long data,
                 wake_up_process(child);
                 /* give it a chance to run. */
                 ret = 0;
-                goto out;
+                break;
 
         default:
                 ret = ptrace_request(child, request, addr, data);
-                goto out;
+                break;
         }
- out:
-        put_task_struct(child);
- out_notsk:
-        unlock_kernel();
         return ret;
 }
 
diff --git a/include/asm-alpha/ptrace.h b/include/asm-alpha/ptrace.h
index 9933b8b3612e..32c7a5cddd59 100644
--- a/include/asm-alpha/ptrace.h
+++ b/include/asm-alpha/ptrace.h
@@ -68,8 +68,6 @@ struct switch_stack {
 
 #ifdef __KERNEL__
 
-#define __ARCH_SYS_PTRACE       1
-
 #define user_mode(regs) (((regs)->ps & 8) != 0)
 #define instruction_pointer(regs) ((regs)->pc)
 #define profile_pc(regs) instruction_pointer(regs)