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, 23 insertions, 23 deletions

diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c
index e39fdec8a0b0..52de29000c7e 100644
--- a/fs/userfaultfd.c
+++ b/fs/userfaultfd.c
@@ -234,7 +234,7 @@ static inline bool userfaultfd_huge_must_wait(struct userfaultfd_ctx *ctx,
 	pte_t *ptep, pte;
 	bool ret = true;
 
-	VM_BUG_ON(!rwsem_is_locked(&mm->mmap_sem));
+	mmap_assert_locked(mm);
 
 	ptep = huge_pte_offset(mm, address, vma_mmu_pagesize(vma));
 
@@ -286,7 +286,7 @@ static inline bool userfaultfd_must_wait(struct userfaultfd_ctx *ctx,
 	pte_t *pte;
 	bool ret = true;
 
-	VM_BUG_ON(!rwsem_is_locked(&mm->mmap_sem));
+	mmap_assert_locked(mm);
 
 	pgd = pgd_offset(mm, address);
 	if (!pgd_present(*pgd))
@@ -369,13 +369,13 @@ static inline bool userfaultfd_signal_pending(unsigned int flags)
  * FAULT_FLAG_KILLABLE are not straightforward. The "Caution"
  * recommendation in __lock_page_or_retry is not an understatement.
  *
- * If FAULT_FLAG_ALLOW_RETRY is set, the mmap_sem must be released
+ * If FAULT_FLAG_ALLOW_RETRY is set, the mmap_lock must be released
  * before returning VM_FAULT_RETRY only if FAULT_FLAG_RETRY_NOWAIT is
  * not set.
  *
  * If FAULT_FLAG_ALLOW_RETRY is set but FAULT_FLAG_KILLABLE is not
  * set, VM_FAULT_RETRY can still be returned if and only if there are
- * fatal_signal_pending()s, and the mmap_sem must be released before
+ * fatal_signal_pending()s, and the mmap_lock must be released before
  * returning it.
  */
 vm_fault_t handle_userfault(struct vm_fault *vmf, unsigned long reason)
@@ -396,16 +396,16 @@ vm_fault_t handle_userfault(struct vm_fault *vmf, unsigned long reason)
 	 * FOLL_DUMP case, anon memory also checks for FOLL_DUMP with
 	 * the no_page_table() helper in follow_page_mask(), but the
 	 * shmem_vm_ops->fault method is invoked even during
-	 * coredumping without mmap_sem and it ends up here.
+	 * coredumping without mmap_lock and it ends up here.
 	 */
 	if (current->flags & (PF_EXITING|PF_DUMPCORE))
 		goto out;
 
 	/*
-	 * Coredumping runs without mmap_sem so we can only check that
-	 * the mmap_sem is held, if PF_DUMPCORE was not set.
+	 * Coredumping runs without mmap_lock so we can only check that
+	 * the mmap_lock is held, if PF_DUMPCORE was not set.
 	 */
-	WARN_ON_ONCE(!rwsem_is_locked(&mm->mmap_sem));
+	mmap_assert_locked(mm);
 
 	ctx = vmf->vma->vm_userfaultfd_ctx.ctx;
 	if (!ctx)
@@ -422,7 +422,7 @@ vm_fault_t handle_userfault(struct vm_fault *vmf, unsigned long reason)
 	/*
 	 * If it's already released don't get it. This avoids to loop
 	 * in __get_user_pages if userfaultfd_release waits on the
-	 * caller of handle_userfault to release the mmap_sem.
+	 * caller of handle_userfault to release the mmap_lock.
 	 */
 	if (unlikely(READ_ONCE(ctx->released))) {
 		/*
@@ -481,7 +481,7 @@ vm_fault_t handle_userfault(struct vm_fault *vmf, unsigned long reason)
 	if (vmf->flags & FAULT_FLAG_RETRY_NOWAIT)
 		goto out;
 
-	/* take the reference before dropping the mmap_sem */
+	/* take the reference before dropping the mmap_lock */
 	userfaultfd_ctx_get(ctx);
 
 	init_waitqueue_func_entry(&uwq.wq, userfaultfd_wake_function);
@@ -514,7 +514,7 @@ vm_fault_t handle_userfault(struct vm_fault *vmf, unsigned long reason)
 		must_wait = userfaultfd_huge_must_wait(ctx, vmf->vma,
 						       vmf->address,
 						       vmf->flags, reason);
-	up_read(&mm->mmap_sem);
+	mmap_read_unlock(mm);
 
 	if (likely(must_wait && !READ_ONCE(ctx->released) &&
 		   !userfaultfd_signal_pending(vmf->flags))) {
@@ -637,7 +637,7 @@ static void userfaultfd_event_wait_completion(struct userfaultfd_ctx *ctx,
 		struct mm_struct *mm = release_new_ctx->mm;
 
 		/* the various vma->vm_userfaultfd_ctx still points to it */
-		down_write(&mm->mmap_sem);
+		mmap_write_lock(mm);
 		/* no task can run (and in turn coredump) yet */
 		VM_WARN_ON(!mmget_still_valid(mm));
 		for (vma = mm->mmap; vma; vma = vma->vm_next)
@@ -645,7 +645,7 @@ static void userfaultfd_event_wait_completion(struct userfaultfd_ctx *ctx,
 				vma->vm_userfaultfd_ctx = NULL_VM_UFFD_CTX;
 				vma->vm_flags &= ~(VM_UFFD_WP | VM_UFFD_MISSING);
 			}
-		up_write(&mm->mmap_sem);
+		mmap_write_unlock(mm);
 
 		userfaultfd_ctx_put(release_new_ctx);
 	}
@@ -799,7 +799,7 @@ bool userfaultfd_remove(struct vm_area_struct *vma,
 
 	userfaultfd_ctx_get(ctx);
 	WRITE_ONCE(ctx->mmap_changing, true);
-	up_read(&mm->mmap_sem);
+	mmap_read_unlock(mm);
 
 	msg_init(&ewq.msg);
 
@@ -890,11 +890,11 @@ static int userfaultfd_release(struct inode *inode, struct file *file)
 	 * Flush page faults out of all CPUs. NOTE: all page faults
 	 * must be retried without returning VM_FAULT_SIGBUS if
 	 * userfaultfd_ctx_get() succeeds but vma->vma_userfault_ctx
-	 * changes while handle_userfault released the mmap_sem. So
+	 * changes while handle_userfault released the mmap_lock. So
 	 * it's critical that released is set to true (above), before
-	 * taking the mmap_sem for writing.
+	 * taking the mmap_lock for writing.
 	 */
-	down_write(&mm->mmap_sem);
+	mmap_write_lock(mm);
 	still_valid = mmget_still_valid(mm);
 	prev = NULL;
 	for (vma = mm->mmap; vma; vma = vma->vm_next) {
@@ -920,7 +920,7 @@ static int userfaultfd_release(struct inode *inode, struct file *file)
 		vma->vm_flags = new_flags;
 		vma->vm_userfaultfd_ctx = NULL_VM_UFFD_CTX;
 	}
-	up_write(&mm->mmap_sem);
+	mmap_write_unlock(mm);
 	mmput(mm);
 wakeup:
 	/*
@@ -1248,7 +1248,7 @@ static __always_inline void wake_userfault(struct userfaultfd_ctx *ctx,
 	/*
 	 * To be sure waitqueue_active() is not reordered by the CPU
 	 * before the pagetable update, use an explicit SMP memory
-	 * barrier here. PT lock release or up_read(mmap_sem) still
+	 * barrier here. PT lock release or mmap_read_unlock(mm) still
 	 * have release semantics that can allow the
 	 * waitqueue_active() to be reordered before the pte update.
 	 */
@@ -1345,7 +1345,7 @@ static int userfaultfd_register(struct userfaultfd_ctx *ctx,
 	if (!mmget_not_zero(mm))
 		goto out;
 
-	down_write(&mm->mmap_sem);
+	mmap_write_lock(mm);
 	if (!mmget_still_valid(mm))
 		goto out_unlock;
 	vma = find_vma_prev(mm, start, &prev);
@@ -1492,7 +1492,7 @@ static int userfaultfd_register(struct userfaultfd_ctx *ctx,
 		vma = vma->vm_next;
 	} while (vma && vma->vm_start < end);
 out_unlock:
-	up_write(&mm->mmap_sem);
+	mmap_write_unlock(mm);
 	mmput(mm);
 	if (!ret) {
 		__u64 ioctls_out;
@@ -1547,7 +1547,7 @@ static int userfaultfd_unregister(struct userfaultfd_ctx *ctx,
 	if (!mmget_not_zero(mm))
 		goto out;
 
-	down_write(&mm->mmap_sem);
+	mmap_write_lock(mm);
 	if (!mmget_still_valid(mm))
 		goto out_unlock;
 	vma = find_vma_prev(mm, start, &prev);
@@ -1664,7 +1664,7 @@ static int userfaultfd_unregister(struct userfaultfd_ctx *ctx,
 		vma = vma->vm_next;
 	} while (vma && vma->vm_start < end);
 out_unlock:
-	up_write(&mm->mmap_sem);
+	mmap_write_unlock(mm);
 	mmput(mm);
 out:
 	return ret;