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, 90 insertions, 0 deletions

diff --git a/include/linux/mmap_lock.h b/include/linux/mmap_lock.h
new file mode 100644
index 000000000000..0707671851a8
--- /dev/null
+++ b/include/linux/mmap_lock.h
@@ -0,0 +1,90 @@
+#ifndef _LINUX_MMAP_LOCK_H
+#define _LINUX_MMAP_LOCK_H
+
+#include <linux/mmdebug.h>
+
+#define MMAP_LOCK_INITIALIZER(name) \
+	.mmap_lock = __RWSEM_INITIALIZER((name).mmap_lock),
+
+static inline void mmap_init_lock(struct mm_struct *mm)
+{
+	init_rwsem(&mm->mmap_lock);
+}
+
+static inline void mmap_write_lock(struct mm_struct *mm)
+{
+	down_write(&mm->mmap_lock);
+}
+
+static inline void mmap_write_lock_nested(struct mm_struct *mm, int subclass)
+{
+	down_write_nested(&mm->mmap_lock, subclass);
+}
+
+static inline int mmap_write_lock_killable(struct mm_struct *mm)
+{
+	return down_write_killable(&mm->mmap_lock);
+}
+
+static inline bool mmap_write_trylock(struct mm_struct *mm)
+{
+	return down_write_trylock(&mm->mmap_lock) != 0;
+}
+
+static inline void mmap_write_unlock(struct mm_struct *mm)
+{
+	up_write(&mm->mmap_lock);
+}
+
+static inline void mmap_write_downgrade(struct mm_struct *mm)
+{
+	downgrade_write(&mm->mmap_lock);
+}
+
+static inline void mmap_read_lock(struct mm_struct *mm)
+{
+	down_read(&mm->mmap_lock);
+}
+
+static inline int mmap_read_lock_killable(struct mm_struct *mm)
+{
+	return down_read_killable(&mm->mmap_lock);
+}
+
+static inline bool mmap_read_trylock(struct mm_struct *mm)
+{
+	return down_read_trylock(&mm->mmap_lock) != 0;
+}
+
+static inline void mmap_read_unlock(struct mm_struct *mm)
+{
+	up_read(&mm->mmap_lock);
+}
+
+static inline bool mmap_read_trylock_non_owner(struct mm_struct *mm)
+{
+	if (down_read_trylock(&mm->mmap_lock)) {
+		rwsem_release(&mm->mmap_lock.dep_map, _RET_IP_);
+		return true;
+	}
+	return false;
+}
+
+static inline void mmap_read_unlock_non_owner(struct mm_struct *mm)
+{
+	up_read_non_owner(&mm->mmap_lock);
+}
+
+static inline void mmap_assert_locked(struct mm_struct *mm)
+{
+	lockdep_assert_held(&mm->mmap_lock);
+	VM_BUG_ON_MM(!rwsem_is_locked(&mm->mmap_lock), mm);
+}
+
+static inline void mmap_assert_write_locked(struct mm_struct *mm)
+{
+	lockdep_assert_held_write(&mm->mmap_lock);
+	VM_BUG_ON_MM(!rwsem_is_locked(&mm->mmap_lock), mm);
+}
+
+#endif /* _LINUX_MMAP_LOCK_H */