ptrace: powerpc: implement user_single_step_siginfo()

Suggested by Roland.

Implement user_single_step_siginfo() for powerpc.
Signed-off-by: NOleg Nesterov <oleg@redhat.com>
Acked-by: NRoland McGrath <roland@redhat.com>
Cc: <linux-arch@vger.kernel.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

arch/powerpc/include/asm/ptrace.h

@@ -140,6 +140,8 @@ extern void user_enable_single_step(struct task_struct *);
 extern void user_enable_block_step(struct task_struct *);
 extern void user_disable_single_step(struct task_struct *);
 
+#define ARCH_HAS_USER_SINGLE_STEP_INFO
+
 #endif /* __ASSEMBLY__ */
 
 #endif /* __KERNEL__ */

arch/powerpc/kernel/traps.c

@@ -174,6 +174,15 @@ int die(const char *str, struct pt_regs *regs, long err)
 	return 0;
 }
 
+void user_single_step_siginfo(struct task_struct *tsk,
+				struct pt_regs *regs, siginfo_t *info)
+{
+	memset(info, 0, sizeof(*info));
+	info->si_signo = SIGTRAP;
+	info->si_code = TRAP_TRACE;
+	info->si_addr = (void __user *)regs->nip;
+}
+
 void _exception(int signr, struct pt_regs *regs, int code, unsigned long addr)
 {
 	siginfo_t info;