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, 37 insertions, 37 deletions

diff --git a/mm/mmap.c b/mm/mmap.c
index 39bd60c20a82..59a4682ebf3f 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -132,7 +132,7 @@ void vma_set_page_prot(struct vm_area_struct *vma)
 		vm_flags &= ~VM_SHARED;
 		vm_page_prot = vm_pgprot_modify(vm_page_prot, vm_flags);
 	}
-	/* remove_protection_ptes reads vma->vm_page_prot without mmap_sem */
+	/* remove_protection_ptes reads vma->vm_page_prot without mmap_lock */
 	WRITE_ONCE(vma->vm_page_prot, vm_page_prot);
 }
 
@@ -198,7 +198,7 @@ SYSCALL_DEFINE1(brk, unsigned long, brk)
 	bool downgraded = false;
 	LIST_HEAD(uf);
 
-	if (down_write_killable(&mm->mmap_sem))
+	if (mmap_write_lock_killable(mm))
 		return -EINTR;
 
 	origbrk = mm->brk;
@@ -238,14 +238,14 @@ SYSCALL_DEFINE1(brk, unsigned long, brk)
 
 	/*
 	 * Always allow shrinking brk.
-	 * __do_munmap() may downgrade mmap_sem to read.
+	 * __do_munmap() may downgrade mmap_lock to read.
 	 */
 	if (brk <= mm->brk) {
 		int ret;
 
 		/*
-		 * mm->brk must to be protected by write mmap_sem so update it
-		 * before downgrading mmap_sem. When __do_munmap() fails,
+		 * mm->brk must to be protected by write mmap_lock so update it
+		 * before downgrading mmap_lock. When __do_munmap() fails,
 		 * mm->brk will be restored from origbrk.
 		 */
 		mm->brk = brk;
@@ -272,9 +272,9 @@ SYSCALL_DEFINE1(brk, unsigned long, brk)
 success:
 	populate = newbrk > oldbrk && (mm->def_flags & VM_LOCKED) != 0;
 	if (downgraded)
-		up_read(&mm->mmap_sem);
+		mmap_read_unlock(mm);
 	else
-		up_write(&mm->mmap_sem);
+		mmap_write_unlock(mm);
 	userfaultfd_unmap_complete(mm, &uf);
 	if (populate)
 		mm_populate(oldbrk, newbrk - oldbrk);
@@ -282,7 +282,7 @@ success:
 
 out:
 	retval = origbrk;
-	up_write(&mm->mmap_sem);
+	mmap_write_unlock(mm);
 	return retval;
 }
 
@@ -505,7 +505,7 @@ static __always_inline void vma_rb_erase(struct vm_area_struct *vma,
  * After the update, the vma will be reinserted using
  * anon_vma_interval_tree_post_update_vma().
  *
- * The entire update must be protected by exclusive mmap_sem and by
+ * The entire update must be protected by exclusive mmap_lock and by
  * the root anon_vma's mutex.
  */
 static inline void
@@ -1361,7 +1361,7 @@ static inline bool file_mmap_ok(struct file *file, struct inode *inode,
 }
 
 /*
- * The caller must hold down_write(&current->mm->mmap_sem).
+ * The caller must write-lock current->mm->mmap_lock.
  */
 unsigned long do_mmap(struct file *file, unsigned long addr,
 			unsigned long len, unsigned long prot,
@@ -2371,7 +2371,7 @@ int expand_upwards(struct vm_area_struct *vma, unsigned long address)
 
 	/*
 	 * vma->vm_start/vm_end cannot change under us because the caller
-	 * is required to hold the mmap_sem in read mode.  We need the
+	 * is required to hold the mmap_lock in read mode.  We need the
 	 * anon_vma lock to serialize against concurrent expand_stacks.
 	 */
 	anon_vma_lock_write(vma->anon_vma);
@@ -2389,7 +2389,7 @@ int expand_upwards(struct vm_area_struct *vma, unsigned long address)
 			if (!error) {
 				/*
 				 * vma_gap_update() doesn't support concurrent
-				 * updates, but we only hold a shared mmap_sem
+				 * updates, but we only hold a shared mmap_lock
 				 * lock here, so we need to protect against
 				 * concurrent vma expansions.
 				 * anon_vma_lock_write() doesn't help here, as
@@ -2451,7 +2451,7 @@ int expand_downwards(struct vm_area_struct *vma,
 
 	/*
 	 * vma->vm_start/vm_end cannot change under us because the caller
-	 * is required to hold the mmap_sem in read mode.  We need the
+	 * is required to hold the mmap_lock in read mode.  We need the
 	 * anon_vma lock to serialize against concurrent expand_stacks.
 	 */
 	anon_vma_lock_write(vma->anon_vma);
@@ -2469,7 +2469,7 @@ int expand_downwards(struct vm_area_struct *vma,
 			if (!error) {
 				/*
 				 * vma_gap_update() doesn't support concurrent
-				 * updates, but we only hold a shared mmap_sem
+				 * updates, but we only hold a shared mmap_lock
 				 * lock here, so we need to protect against
 				 * concurrent vma expansions.
 				 * anon_vma_lock_write() doesn't help here, as
@@ -2828,7 +2828,7 @@ int __do_munmap(struct mm_struct *mm, unsigned long start, size_t len,
 	detach_vmas_to_be_unmapped(mm, vma, prev, end);
 
 	if (downgrade)
-		downgrade_write(&mm->mmap_sem);
+		mmap_write_downgrade(mm);
 
 	unmap_region(mm, vma, prev, start, end);
 
@@ -2850,20 +2850,20 @@ static int __vm_munmap(unsigned long start, size_t len, bool downgrade)
 	struct mm_struct *mm = current->mm;
 	LIST_HEAD(uf);
 
-	if (down_write_killable(&mm->mmap_sem))
+	if (mmap_write_lock_killable(mm))
 		return -EINTR;
 
 	ret = __do_munmap(mm, start, len, &uf, downgrade);
 	/*
-	 * Returning 1 indicates mmap_sem is downgraded.
+	 * Returning 1 indicates mmap_lock is downgraded.
 	 * But 1 is not legal return value of vm_munmap() and munmap(), reset
 	 * it to 0 before return.
 	 */
 	if (ret == 1) {
-		up_read(&mm->mmap_sem);
+		mmap_read_unlock(mm);
 		ret = 0;
 	} else
-		up_write(&mm->mmap_sem);
+		mmap_write_unlock(mm);
 
 	userfaultfd_unmap_complete(mm, &uf);
 	return ret;
@@ -2911,7 +2911,7 @@ SYSCALL_DEFINE5(remap_file_pages, unsigned long, start, unsigned long, size,
 	if (pgoff + (size >> PAGE_SHIFT) < pgoff)
 		return ret;
 
-	if (down_write_killable(&mm->mmap_sem))
+	if (mmap_write_lock_killable(mm))
 		return -EINTR;
 
 	vma = find_vma(mm, start);
@@ -2974,7 +2974,7 @@ SYSCALL_DEFINE5(remap_file_pages, unsigned long, start, unsigned long, size,
 			prot, flags, pgoff, &populate, NULL);
 	fput(file);
 out:
-	up_write(&mm->mmap_sem);
+	mmap_write_unlock(mm);
 	if (populate)
 		mm_populate(ret, populate);
 	if (!IS_ERR_VALUE(ret))
@@ -3074,12 +3074,12 @@ int vm_brk_flags(unsigned long addr, unsigned long request, unsigned long flags)
 	if (!len)
 		return 0;
 
-	if (down_write_killable(&mm->mmap_sem))
+	if (mmap_write_lock_killable(mm))
 		return -EINTR;
 
 	ret = do_brk_flags(addr, len, flags, &uf);
 	populate = ((mm->def_flags & VM_LOCKED) != 0);
-	up_write(&mm->mmap_sem);
+	mmap_write_unlock(mm);
 	userfaultfd_unmap_complete(mm, &uf);
 	if (populate && !ret)
 		mm_populate(addr, len);
@@ -3107,12 +3107,12 @@ void exit_mmap(struct mm_struct *mm)
 		/*
 		 * Manually reap the mm to free as much memory as possible.
 		 * Then, as the oom reaper does, set MMF_OOM_SKIP to disregard
-		 * this mm from further consideration.  Taking mm->mmap_sem for
+		 * this mm from further consideration.  Taking mm->mmap_lock for
 		 * write after setting MMF_OOM_SKIP will guarantee that the oom
-		 * reaper will not run on this mm again after mmap_sem is
+		 * reaper will not run on this mm again after mmap_lock is
 		 * dropped.
 		 *
-		 * Nothing can be holding mm->mmap_sem here and the above call
+		 * Nothing can be holding mm->mmap_lock here and the above call
 		 * to mmu_notifier_release(mm) ensures mmu notifier callbacks in
 		 * __oom_reap_task_mm() will not block.
 		 *
@@ -3123,8 +3123,8 @@ void exit_mmap(struct mm_struct *mm)
 		(void)__oom_reap_task_mm(mm);
 
 		set_bit(MMF_OOM_SKIP, &mm->flags);
-		down_write(&mm->mmap_sem);
-		up_write(&mm->mmap_sem);
+		mmap_write_lock(mm);
+		mmap_write_unlock(mm);
 	}
 
 	if (mm->locked_vm) {
@@ -3437,7 +3437,7 @@ bool vma_is_special_mapping(const struct vm_area_struct *vma,
 }
 
 /*
- * Called with mm->mmap_sem held for writing.
+ * Called with mm->mmap_lock held for writing.
  * Insert a new vma covering the given region, with the given flags.
  * Its pages are supplied by the given array of struct page *.
  * The array can be shorter than len >> PAGE_SHIFT if it's null-terminated.
@@ -3474,7 +3474,7 @@ static void vm_lock_anon_vma(struct mm_struct *mm, struct anon_vma *anon_vma)
 		 * The LSB of head.next can't change from under us
 		 * because we hold the mm_all_locks_mutex.
 		 */
-		down_write_nest_lock(&anon_vma->root->rwsem, &mm->mmap_sem);
+		down_write_nest_lock(&anon_vma->root->rwsem, &mm->mmap_lock);
 		/*
 		 * We can safely modify head.next after taking the
 		 * anon_vma->root->rwsem. If some other vma in this mm shares
@@ -3504,7 +3504,7 @@ static void vm_lock_mapping(struct mm_struct *mm, struct address_space *mapping)
 		 */
 		if (test_and_set_bit(AS_MM_ALL_LOCKS, &mapping->flags))
 			BUG();
-		down_write_nest_lock(&mapping->i_mmap_rwsem, &mm->mmap_sem);
+		down_write_nest_lock(&mapping->i_mmap_rwsem, &mm->mmap_lock);
 	}
 }
 
@@ -3513,11 +3513,11 @@ static void vm_lock_mapping(struct mm_struct *mm, struct address_space *mapping)
  * operations that could ever happen on a certain mm. This includes
  * vmtruncate, try_to_unmap, and all page faults.
  *
- * The caller must take the mmap_sem in write mode before calling
+ * The caller must take the mmap_lock in write mode before calling
  * mm_take_all_locks(). The caller isn't allowed to release the
- * mmap_sem until mm_drop_all_locks() returns.
+ * mmap_lock until mm_drop_all_locks() returns.
  *
- * mmap_sem in write mode is required in order to block all operations
+ * mmap_lock in write mode is required in order to block all operations
  * that could modify pagetables and free pages without need of
  * altering the vma layout. It's also needed in write mode to avoid new
  * anon_vmas to be associated with existing vmas.
@@ -3550,7 +3550,7 @@ int mm_take_all_locks(struct mm_struct *mm)
 	struct vm_area_struct *vma;
 	struct anon_vma_chain *avc;
 
-	BUG_ON(down_read_trylock(&mm->mmap_sem));
+	BUG_ON(mmap_read_trylock(mm));
 
 	mutex_lock(&mm_all_locks_mutex);
 
@@ -3622,7 +3622,7 @@ static void vm_unlock_mapping(struct address_space *mapping)
 }
 
 /*
- * The mmap_sem cannot be released by the caller until
+ * The mmap_lock cannot be released by the caller until
  * mm_drop_all_locks() returns.
  */
 void mm_drop_all_locks(struct mm_struct *mm)
@@ -3630,7 +3630,7 @@ void mm_drop_all_locks(struct mm_struct *mm)
 	struct vm_area_struct *vma;
 	struct anon_vma_chain *avc;
 
-	BUG_ON(down_read_trylock(&mm->mmap_sem));
+	BUG_ON(mmap_read_trylock(mm));
 	BUG_ON(!mutex_is_locked(&mm_all_locks_mutex));
 
 	for (vma = mm->mmap; vma; vma = vma->vm_next) {