Merge branch 'akpm' (patches from Andrew)

Merge even more updates from Andrew Morton:

 - a kernel-wide sweep of show_stack()

 - pagetable cleanups

 - abstract out accesses to mmap_sem - prep for mmap_sem scalability work

 - hch's user acess work

Subsystems affected by this patch series: debug, mm/pagemap, mm/maccess,
mm/documentation.

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (93 commits)
  include/linux/cache.h: expand documentation over __read_mostly
  maccess: return -ERANGE when probe_kernel_read() fails
  x86: use non-set_fs based maccess routines
  maccess: allow architectures to provide kernel probing directly
  maccess: move user access routines together
  maccess: always use strict semantics for probe_kernel_read
  maccess: remove strncpy_from_unsafe
  tracing/kprobes: handle mixed kernel/userspace probes better
  bpf: rework the compat kernel probe handling
  bpf:bpf_seq_printf(): handle potentially unsafe format string better
  bpf: handle the compat string in bpf_trace_copy_string better
  bpf: factor out a bpf_trace_copy_string helper
  maccess: unify the probe kernel arch hooks
  maccess: remove probe_read_common and probe_write_common
  maccess: rename strnlen_unsafe_user to strnlen_user_nofault
  maccess: rename strncpy_from_unsafe_strict to strncpy_from_kernel_nofault
  maccess: rename strncpy_from_unsafe_user to strncpy_from_user_nofault
  maccess: update the top of file comment
  maccess: clarify kerneldoc comments
  maccess: remove duplicate kerneldoc comments
  ...

1 files changed, 7 insertions, 6 deletions

diff --git a/include/linux/mmu_notifier.h b/include/linux/mmu_notifier.h
index 736f6918335e..fc68f3570e19 100644
--- a/include/linux/mmu_notifier.h
+++ b/include/linux/mmu_notifier.h
@@ -5,6 +5,7 @@
 #include <linux/list.h>
 #include <linux/spinlock.h>
 #include <linux/mm_types.h>
+#include <linux/mmap_lock.h>
 #include <linux/srcu.h>
 #include <linux/interval_tree.h>
 
@@ -121,7 +122,7 @@ struct mmu_notifier_ops {
 
 	/*
 	 * invalidate_range_start() and invalidate_range_end() must be
-	 * paired and are called only when the mmap_sem and/or the
+	 * paired and are called only when the mmap_lock and/or the
 	 * locks protecting the reverse maps are held. If the subsystem
 	 * can't guarantee that no additional references are taken to
 	 * the pages in the range, it has to implement the
@@ -212,13 +213,13 @@ struct mmu_notifier_ops {
 };
 
 /*
- * The notifier chains are protected by mmap_sem and/or the reverse map
+ * The notifier chains are protected by mmap_lock and/or the reverse map
  * semaphores. Notifier chains are only changed when all reverse maps and
- * the mmap_sem locks are taken.
+ * the mmap_lock locks are taken.
  *
  * Therefore notifier chains can only be traversed when either
  *
- * 1. mmap_sem is held.
+ * 1. mmap_lock is held.
  * 2. One of the reverse map locks is held (i_mmap_rwsem or anon_vma->rwsem).
  * 3. No other concurrent thread can access the list (release)
  */
@@ -277,9 +278,9 @@ mmu_notifier_get(const struct mmu_notifier_ops *ops, struct mm_struct *mm)
 {
 	struct mmu_notifier *ret;
 
-	down_write(&mm->mmap_sem);
+	mmap_write_lock(mm);
 	ret = mmu_notifier_get_locked(ops, mm);
-	up_write(&mm->mmap_sem);
+	mmap_write_unlock(mm);
 	return ret;
 }
 void mmu_notifier_put(struct mmu_notifier *subscription);