1 files changed, 0 insertions, 252 deletions
diff --git a/mm/memory.c b/mm/memory.c
index 71c255f3fdcc..f18266b5a0a9 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -6378,258 +6378,6 @@ out:
 }
 EXPORT_SYMBOL_GPL(handle_mm_fault);
 
-#ifdef CONFIG_LOCK_MM_AND_FIND_VMA
-#include <linux/extable.h>
-
-static inline bool get_mmap_lock_carefully(struct mm_struct *mm, struct pt_regs *regs)
-{
-	if (likely(mmap_read_trylock(mm)))
-		return true;
-
-	if (regs && !user_mode(regs)) {
-		unsigned long ip = exception_ip(regs);
-		if (!search_exception_tables(ip))
-			return false;
-	}
-
-	return !mmap_read_lock_killable(mm);
-}
-
-static inline bool mmap_upgrade_trylock(struct mm_struct *mm)
-{
-	/*
-	 * We don't have this operation yet.
-	 *
-	 * It should be easy enough to do: it's basically a
-	 *    atomic_long_try_cmpxchg_acquire()
-	 * from RWSEM_READER_BIAS -> RWSEM_WRITER_LOCKED, but
-	 * it also needs the proper lockdep magic etc.
-	 */
-	return false;
-}
-
-static inline bool upgrade_mmap_lock_carefully(struct mm_struct *mm, struct pt_regs *regs)
-{
-	mmap_read_unlock(mm);
-	if (regs && !user_mode(regs)) {
-		unsigned long ip = exception_ip(regs);
-		if (!search_exception_tables(ip))
-			return false;
-	}
-	return !mmap_write_lock_killable(mm);
-}
-
-/*
- * Helper for page fault handling.
- *
- * This is kind of equivalent to "mmap_read_lock()" followed
- * by "find_extend_vma()", except it's a lot more careful about
- * the locking (and will drop the lock on failure).
- *
- * For example, if we have a kernel bug that causes a page
- * fault, we don't want to just use mmap_read_lock() to get
- * the mm lock, because that would deadlock if the bug were
- * to happen while we're holding the mm lock for writing.
- *
- * So this checks the exception tables on kernel faults in
- * order to only do this all for instructions that are actually
- * expected to fault.
- *
- * We can also actually take the mm lock for writing if we
- * need to extend the vma, which helps the VM layer a lot.
- */
-struct vm_area_struct *lock_mm_and_find_vma(struct mm_struct *mm,
-			unsigned long addr, struct pt_regs *regs)
-{
-	struct vm_area_struct *vma;
-
-	if (!get_mmap_lock_carefully(mm, regs))
-		return NULL;
-
-	vma = find_vma(mm, addr);
-	if (likely(vma && (vma->vm_start <= addr)))
-		return vma;
-
-	/*
-	 * Well, dang. We might still be successful, but only
-	 * if we can extend a vma to do so.
-	 */
-	if (!vma || !(vma->vm_flags & VM_GROWSDOWN)) {
-		mmap_read_unlock(mm);
-		return NULL;
-	}
-
-	/*
-	 * We can try to upgrade the mmap lock atomically,
-	 * in which case we can continue to use the vma
-	 * we already looked up.
-	 *
-	 * Otherwise we'll have to drop the mmap lock and
-	 * re-take it, and also look up the vma again,
-	 * re-checking it.
-	 */
-	if (!mmap_upgrade_trylock(mm)) {
-		if (!upgrade_mmap_lock_carefully(mm, regs))
-			return NULL;
-
-		vma = find_vma(mm, addr);
-		if (!vma)
-			goto fail;
-		if (vma->vm_start <= addr)
-			goto success;
-		if (!(vma->vm_flags & VM_GROWSDOWN))
-			goto fail;
-	}
-
-	if (expand_stack_locked(vma, addr))
-		goto fail;
-
-success:
-	mmap_write_downgrade(mm);
-	return vma;
-
-fail:
-	mmap_write_unlock(mm);
-	return NULL;
-}
-#endif
-
-#ifdef CONFIG_PER_VMA_LOCK
-static inline bool __vma_enter_locked(struct vm_area_struct *vma, bool detaching)
-{
-	unsigned int tgt_refcnt = VMA_LOCK_OFFSET;
-
-	/* Additional refcnt if the vma is attached. */
-	if (!detaching)
-		tgt_refcnt++;
-
-	/*
-	 * If vma is detached then only vma_mark_attached() can raise the
-	 * vm_refcnt. mmap_write_lock prevents racing with vma_mark_attached().
-	 */
-	if (!refcount_add_not_zero(VMA_LOCK_OFFSET, &vma->vm_refcnt))
-		return false;
-
-	rwsem_acquire(&vma->vmlock_dep_map, 0, 0, _RET_IP_);
-	rcuwait_wait_event(&vma->vm_mm->vma_writer_wait,
-		   refcount_read(&vma->vm_refcnt) == tgt_refcnt,
-		   TASK_UNINTERRUPTIBLE);
-	lock_acquired(&vma->vmlock_dep_map, _RET_IP_);
-
-	return true;
-}
-
-static inline void __vma_exit_locked(struct vm_area_struct *vma, bool *detached)
-{
-	*detached = refcount_sub_and_test(VMA_LOCK_OFFSET, &vma->vm_refcnt);
-	rwsem_release(&vma->vmlock_dep_map, _RET_IP_);
-}
-
-void __vma_start_write(struct vm_area_struct *vma, unsigned int mm_lock_seq)
-{
-	bool locked;
-
-	/*
-	 * __vma_enter_locked() returns false immediately if the vma is not
-	 * attached, otherwise it waits until refcnt is indicating that vma
-	 * is attached with no readers.
-	 */
-	locked = __vma_enter_locked(vma, false);
-
-	/*
-	 * We should use WRITE_ONCE() here because we can have concurrent reads
-	 * from the early lockless pessimistic check in vma_start_read().
-	 * We don't really care about the correctness of that early check, but
-	 * we should use WRITE_ONCE() for cleanliness and to keep KCSAN happy.
-	 */
-	WRITE_ONCE(vma->vm_lock_seq, mm_lock_seq);
-
-	if (locked) {
-		bool detached;
-
-		__vma_exit_locked(vma, &detached);
-		WARN_ON_ONCE(detached); /* vma should remain attached */
-	}
-}
-EXPORT_SYMBOL_GPL(__vma_start_write);
-
-void vma_mark_detached(struct vm_area_struct *vma)
-{
-	vma_assert_write_locked(vma);
-	vma_assert_attached(vma);
-
-	/*
-	 * We are the only writer, so no need to use vma_refcount_put().
-	 * The condition below is unlikely because the vma has been already
-	 * write-locked and readers can increment vm_refcnt only temporarily
-	 * before they check vm_lock_seq, realize the vma is locked and drop
-	 * back the vm_refcnt. That is a narrow window for observing a raised
-	 * vm_refcnt.
-	 */
-	if (unlikely(!refcount_dec_and_test(&vma->vm_refcnt))) {
-		/* Wait until vma is detached with no readers. */
-		if (__vma_enter_locked(vma, true)) {
-			bool detached;
-
-			__vma_exit_locked(vma, &detached);
-			WARN_ON_ONCE(!detached);
-		}
-	}
-}
-
-/*
- * Lookup and lock a VMA under RCU protection. Returned VMA is guaranteed to be
- * stable and not isolated. If the VMA is not found or is being modified the
- * function returns NULL.
- */
-struct vm_area_struct *lock_vma_under_rcu(struct mm_struct *mm,
-					  unsigned long address)
-{
-	MA_STATE(mas, &mm->mm_mt, address, address);
-	struct vm_area_struct *vma;
-
-	rcu_read_lock();
-retry:
-	vma = mas_walk(&mas);
-	if (!vma)
-		goto inval;
-
-	vma = vma_start_read(mm, vma);
-	if (IS_ERR_OR_NULL(vma)) {
-		/* Check if the VMA got isolated after we found it */
-		if (PTR_ERR(vma) == -EAGAIN) {
-			count_vm_vma_lock_event(VMA_LOCK_MISS);
-			/* The area was replaced with another one */
-			goto retry;
-		}
-
-		/* Failed to lock the VMA */
-		goto inval;
-	}
-	/*
-	 * At this point, we have a stable reference to a VMA: The VMA is
-	 * locked and we know it hasn't already been isolated.
-	 * From here on, we can access the VMA without worrying about which
-	 * fields are accessible for RCU readers.
-	 */
-
-	/* Check if the vma we locked is the right one. */
-	if (unlikely(vma->vm_mm != mm ||
-		     address < vma->vm_start || address >= vma->vm_end))
-		goto inval_end_read;
-
-	rcu_read_unlock();
-	return vma;
-
-inval_end_read:
-	vma_end_read(vma);
-inval:
-	rcu_read_unlock();
-	count_vm_vma_lock_event(VMA_LOCK_ABORT);
-	return NULL;
-}
-#endif /* CONFIG_PER_VMA_LOCK */
-
 #ifndef __PAGETABLE_P4D_FOLDED
 /*
  * Allocate p4d page table.