sparc64: tracehook syscall

This changes sparc64 syscall tracing to use the new tracehook.h entry
points.

[ Add assembly changes to force an immediate -ENOSYS return from
  the system call when syscall_trace() returns non-zero at syscall
  entry.  -DaveM ]
Signed-off-by: NRoland McGrath <roland@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

arch/sparc64/kernel/entry.h

@@ -22,8 +22,7 @@ extern void do_notify_resume(struct pt_regs *regs,
 			     unsigned long orig_i0,
 			     unsigned long thread_info_flags);
 
-extern asmlinkage void syscall_trace(struct pt_regs *regs,
-				     int syscall_exit_p);
+extern asmlinkage int syscall_trace(struct pt_regs *regs, int syscall_exit_p);
 
 extern void bad_trap_tl1(struct pt_regs *regs, long lvl);
 

arch/sparc64/kernel/ptrace.c

@@ -23,6 +23,7 @@
 #include <linux/audit.h>
 #include <linux/signal.h>
 #include <linux/regset.h>
+#include <linux/tracehook.h>
 #include <linux/compat.h>
 #include <linux/elf.h>
 
@@ -1049,8 +1050,10 @@ long arch_ptrace(struct task_struct *child, long request, long addr, long data)
 	return ret;
 }
 
-asmlinkage void syscall_trace(struct pt_regs *regs, int syscall_exit_p)
+asmlinkage int syscall_trace(struct pt_regs *regs, int syscall_exit_p)
 {
+	int ret = 0;
+
 	/* do the secure computing check first */
 	secure_computing(regs->u_regs[UREG_G1]);
 
@@ -1064,27 +1067,14 @@ asmlinkage void syscall_trace(struct pt_regs *regs, int syscall_exit_p)
 		audit_syscall_exit(result, regs->u_regs[UREG_I0]);
 	}
 
-	if (!(current->ptrace & PT_PTRACED))
-		goto out;
-
-	if (!test_thread_flag(TIF_SYSCALL_TRACE))
-		goto out;
-
-	ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD)
-				 ? 0x80 : 0));
-
-	/*
-	 * this isn't the same as continuing with a signal, but it will do
-	 * for normal use.  strace only continues with a signal if the
-	 * stopping signal is not SIGTRAP.  -brl
-	 */
-	if (current->exit_code) {
-		send_sig(current->exit_code, current, 1);
-		current->exit_code = 0;
+	if (test_thread_flag(TIF_SYSCALL_TRACE)) {
+		if (syscall_exit_p)
+			tracehook_report_syscall_exit(regs, 0);
+		else
+			ret = tracehook_report_syscall_entry(regs);
 	}
 
-out:
-	if (unlikely(current->audit_context) && !syscall_exit_p)
+	if (unlikely(current->audit_context) && !syscall_exit_p && !ret)
 		audit_syscall_entry((test_thread_flag(TIF_32BIT) ?
 				     AUDIT_ARCH_SPARC :
 				     AUDIT_ARCH_SPARC64),
@@ -1093,4 +1083,6 @@ asmlinkage void syscall_trace(struct pt_regs *regs, int syscall_exit_p)
 				    regs->u_regs[UREG_I1],
 				    regs->u_regs[UREG_I2],
 				    regs->u_regs[UREG_I3]);
+
+	return ret;
 }

arch/sparc64/kernel/syscalls.S

@@ -162,6 +162,8 @@ linux_syscall_trace32:
 	add	%sp, PTREGS_OFF, %o0
 	call	syscall_trace
 	 clr	%o1
+	brnz,pn	%o0, 3f
+	 mov	-ENOSYS, %o0
 	srl	%i0, 0, %o0
 	srl	%i4, 0, %o4
 	srl	%i1, 0, %o1
@@ -173,6 +175,8 @@ linux_syscall_trace:
 	add	%sp, PTREGS_OFF, %o0
 	call	syscall_trace
 	 clr	%o1
+	brnz,pn	%o0, 3f
+	 mov	-ENOSYS, %o0
 	mov	%i0, %o0
 	mov	%i1, %o1
 	mov	%i2, %o2