tile: use si_int instead of si_ptr for compat_siginfo

To be compatible with the generic get_compat_sigevent(), the
copy_siginfo_to_user32() and thus copy_siginfo_from_user32()
have to use si_int instead of si_ptr.  Using si_ptr means that
for the case of ILP32 compat code running in big-endian mode,
we would end up copying the high 32 bits of the pointer value
into si_int instead of the desired low 32 bits.
Signed-off-by: NChris Metcalf <cmetcalf@ezchip.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>

arch/tile/kernel/compat_signal.c

@@ -68,7 +68,7 @@ int copy_siginfo_to_user32(struct compat_siginfo __user *to, const siginfo_t *fr
 	if (from->si_code < 0) {
 		err |= __put_user(from->si_pid, &to->si_pid);
 		err |= __put_user(from->si_uid, &to->si_uid);
-		err |= __put_user(ptr_to_compat(from->si_ptr), &to->si_ptr);
+		err |= __put_user(from->si_int, &to->si_int);
 	} else {
 		/*
 		 * First 32bits of unions are always present:
@@ -93,8 +93,7 @@ int copy_siginfo_to_user32(struct compat_siginfo __user *to, const siginfo_t *fr
 			break;
 		case __SI_TIMER >> 16:
 			err |= __put_user(from->si_overrun, &to->si_overrun);
-			err |= __put_user(ptr_to_compat(from->si_ptr),
-					  &to->si_ptr);
+			err |= __put_user(from->si_int, &to->si_int);
 			break;
 			 /* This is not generated by the kernel as of now.  */
 		case __SI_RT >> 16:
@@ -110,19 +109,19 @@ int copy_siginfo_to_user32(struct compat_siginfo __user *to, const siginfo_t *fr
 int copy_siginfo_from_user32(siginfo_t *to, struct compat_siginfo __user *from)
 {
 	int err;
-	u32 ptr32;
 
 	if (!access_ok(VERIFY_READ, from, sizeof(struct compat_siginfo)))
 		return -EFAULT;
 
+	memset(to, 0, sizeof(*to));
+
 	err = __get_user(to->si_signo, &from->si_signo);
 	err |= __get_user(to->si_errno, &from->si_errno);
 	err |= __get_user(to->si_code, &from->si_code);
 
 	err |= __get_user(to->si_pid, &from->si_pid);
 	err |= __get_user(to->si_uid, &from->si_uid);
-	err |= __get_user(ptr32, &from->si_ptr);
-	to->si_ptr = compat_ptr(ptr32);
+	err |= __get_user(to->si_int, &from->si_int);
 
 	return err;
 }