parisc: Wire up PTRACE_GETREGS/PTRACE_SETREGS for compat case

Wire up the missing ptrace requests PTRACE_GETREGS, PTRACE_SETREGS,
PTRACE_GETFPREGS and PTRACE_SETFPREGS when running 32-bit applications
on 64-bit kernels.
Signed-off-by: Helge Deller <deller@gmx.de>
Cc: stable@vger.kernel.org # 4.7+

arch/parisc/kernel/ptrace.c

@@ -126,6 +126,12 @@ long arch_ptrace(struct task_struct *child, long request,
 	unsigned long tmp;
 	long ret = -EIO;
 
+	unsigned long user_regs_struct_size = sizeof(struct user_regs_struct);
+#ifdef CONFIG_64BIT
+	if (is_compat_task())
+		user_regs_struct_size /= 2;
+#endif
+
 	switch (request) {
 
 	/* Read the word at location addr in the USER area.  For ptraced
@@ -181,14 +187,14 @@ long arch_ptrace(struct task_struct *child, long request,
 		return copy_regset_to_user(child,
 					   task_user_regset_view(current),
 					   REGSET_GENERAL,
-					   0, sizeof(struct user_regs_struct),
+					   0, user_regs_struct_size,
 					   datap);
 
 	case PTRACE_SETREGS:	/* Set all gp regs in the child. */
 		return copy_regset_from_user(child,
 					     task_user_regset_view(current),
 					     REGSET_GENERAL,
-					     0, sizeof(struct user_regs_struct),
+					     0, user_regs_struct_size,
 					     datap);
 
 	case PTRACE_GETFPREGS:	/* Get the child FPU state. */
@@ -302,6 +308,11 @@ long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
 			}
 		}
 		break;
+	case PTRACE_GETREGS:
+	case PTRACE_SETREGS:
+	case PTRACE_GETFPREGS:
+	case PTRACE_SETFPREGS:
+		return arch_ptrace(child, request, addr, data);
 
 	default:
 		ret = compat_ptrace_request(child, request, addr, data);