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

Pull s390 updates from Martin Schwidefsky:
 "There are two memory management related changes, the CMMA support for
  KVM to avoid swap-in of freed pages and the split page table lock for
  the PMD level.  These two come with common code changes in mm/.

  A fix for the long standing theoretical TLB flush problem, this one
  comes with a common code change in kernel/sched/.

  Another set of changes is Heikos uaccess work, included is the initial
  set of patches with more to come.

  And fixes and cleanups as usual"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (36 commits)
  s390/con3270: optionally disable auto update
  s390/mm: remove unecessary parameter from pgste_ipte_notify
  s390/mm: remove unnecessary parameter from gmap_do_ipte_notify
  s390/mm: fixing comment so that parameter name match
  s390/smp: limit number of cpus in possible cpu mask
  hypfs: Add clarification for "weight_min" attribute
  s390: update defconfigs
  s390/ptrace: add support for PTRACE_SINGLEBLOCK
  s390/perf: make print_debug_cf() static
  s390/topology: Remove call to update_cpu_masks()
  s390/compat: remove compat exec domain
  s390: select CONFIG_TTY for use of tty in unconditional keyboard driver
  s390/appldata_os: fix cpu array size calculation
  s390/checksum: remove memset() within csum_partial_copy_from_user()
  s390/uaccess: remove copy_from_user_real()
  s390/sclp_early: Return correct HSA block count also for zero
  s390: add some drivers/subsystems to the MAINTAINERS file
  s390: improve debug feature usage
  s390/airq: add support for irq ranges
  s390/mm: enable split page table lock for PMD level
  ...

1 files changed, 2 insertions, 9 deletions

diff --git a/arch/s390/include/asm/checksum.h b/arch/s390/include/asm/checksum.h
index 4f57a4f3909a..740364856355 100644
--- a/arch/s390/include/asm/checksum.h
+++ b/arch/s390/include/asm/checksum.h
@@ -44,22 +44,15 @@ csum_partial(const void *buff, int len, __wsum sum)
  * here even more important to align src and dst on a 32-bit (or even
  * better 64-bit) boundary
  *
- * Copy from userspace and compute checksum.  If we catch an exception
- * then zero the rest of the buffer.
+ * Copy from userspace and compute checksum.
  */
 static inline __wsum
 csum_partial_copy_from_user(const void __user *src, void *dst,
                                           int len, __wsum sum,
                                           int *err_ptr)
 {
-        int missing;
-
-        missing = copy_from_user(dst, src, len);
-        if (missing) {
-                memset(dst + len - missing, 0, missing);
+        if (unlikely(copy_from_user(dst, src, len)))
                 *err_ptr = -EFAULT;
-        }
-                
         return csum_partial(dst, len, sum);
 }