Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

Pull second set of s390 patches from Martin Schwidefsky:
 "The main part of this merge are Heikos uaccess patches.  Together with
  commit 09884964335e ("mm: do not grow the stack vma just because of an
  overrun on preceding vma") the user string access is hopefully fixed
  for good.

  In addition some bug fixes and two cleanup patches."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
  s390/module: fix compile warning
  qdio: remove unused parameters
  s390/uaccess: fix kernel ds access for page table walk
  s390/uaccess: fix strncpy_from_user string length check
  input: disable i8042 PC Keyboard controller for s390
  s390/dis: Fix invalid array size
  s390/uaccess: remove pointless access_ok() checks
  s390/uaccess: fix strncpy_from_user/strnlen_user zero maxlen case
  s390/uaccess: shorten strncpy_from_user/strnlen_user
  s390/dasd: fix unresponsive device after all channel paths were lost
  s390/mm: ignore change bit for vmemmap
  s390/page table dumper: add support for change-recording override bit

1 files changed, 14 insertions, 12 deletions

diff --git a/arch/s390/lib/uaccess_mvcos.c b/arch/s390/lib/uaccess_mvcos.c
index 2443ae476e3..1829742bf47 100644
--- a/arch/s390/lib/uaccess_mvcos.c
+++ b/arch/s390/lib/uaccess_mvcos.c
@@ -162,19 +162,19 @@ static size_t clear_user_mvcos(size_t size, void __user *to)
 
 static size_t strnlen_user_mvcos(size_t count, const char __user *src)
 {
+	size_t done, len, offset, len_str;
 	char buf[256];
-	int rc;
-	size_t done, len, len_str;
 
 	done = 0;
 	do {
-		len = min(count - done, (size_t) 256);
-		rc = uaccess.copy_from_user(len, src + done, buf);
-		if (unlikely(rc == len))
+		offset = (size_t)src & ~PAGE_MASK;
+		len = min(256UL, PAGE_SIZE - offset);
+		len = min(count - done, len);
+		if (copy_from_user_mvcos(len, src, buf))
 			return 0;
-		len -= rc;
 		len_str = strnlen(buf, len);
 		done += len_str;
+		src += len_str;
 	} while ((len_str == len) && (done < count));
 	return done + 1;
 }
@@ -182,18 +182,20 @@ static size_t strnlen_user_mvcos(size_t count, const char __user *src)
 static size_t strncpy_from_user_mvcos(size_t count, const char __user *src,
 				      char *dst)
 {
-	int rc;
-	size_t done, len, len_str;
+	size_t done, len, offset, len_str;
 
+	if (unlikely(!count))
+		return 0;
 	done = 0;
 	do {
-		len = min(count - done, (size_t) 4096);
-		rc = uaccess.copy_from_user(len, src + done, dst);
-		if (unlikely(rc == len))
+		offset = (size_t)src & ~PAGE_MASK;
+		len = min(count - done, PAGE_SIZE - offset);
+		if (copy_from_user_mvcos(len, src, dst))
 			return -EFAULT;
-		len -= rc;
 		len_str = strnlen(dst, len);
 		done += len_str;
+		src += len_str;
+		dst += len_str;
 	} while ((len_str == len) && (done < count));
 	return done;
 }