mm: use rwsem assertion macros for mmap_lock

This slightly strengthens our write assertion when lockdep is disabled.
It also downgrades us from BUG_ON to WARN_ON, but I think that's an
improvement. I don't think dumping the mm_struct was all that valuable;
the call chain is what's important.

Link: https://lkml.kernel.org/r/[e-mail]
Signed-off-by: Matthew Wilcox (Oracle) <[e-mail]>
Reviewed-by: David Hildenbrand <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>

include/linux/mmap_lock.h

···
 
 #endif /* CONFIG_TRACING */
 
-static inline void mmap_assert_locked(struct mm_struct *mm)
+static inline void mmap_assert_locked(const struct mm_struct *mm)
 {
-	lockdep_assert_held(&mm->mmap_lock);
-	VM_BUG_ON_MM(!rwsem_is_locked(&mm->mmap_lock), mm);
+	rwsem_assert_held(&mm->mmap_lock);
 }
 
-static inline void mmap_assert_write_locked(struct mm_struct *mm)
+static inline void mmap_assert_write_locked(const struct mm_struct *mm)
 {
-	lockdep_assert_held_write(&mm->mmap_lock);
-	VM_BUG_ON_MM(!rwsem_is_locked(&mm->mmap_lock), mm);
+	rwsem_assert_held_write(&mm->mmap_lock);
 }
 
 #ifdef CONFIG_PER_VMA_LOCK