diff mbox series

[37/41] mm: introduce mod_vm_flags_nolock

Message ID 20230109205336.3665937-38-surenb@google.com (mailing list archive)
State New
Headers show
Series Per-VMA locks | expand

Commit Message

Suren Baghdasaryan Jan. 9, 2023, 8:53 p.m. UTC 
In cases when VMA flags are modified after VMA was isolated and mmap_lock
was downgraded, flags modifications do not require per-VMA locking and
an attempt to lock the VMA would result in an assertion because mmap
write lock is not held.
Introduce mod_vm_flags_nolock to be used in such situation.

Signed-off-by: Suren Baghdasaryan <surenb@google.com>
---
 include/linux/mm.h | 8 ++++++++
 1 file changed, 8 insertions(+)
diff mbox series

Patch

diff --git a/include/linux/mm.h b/include/linux/mm.h
index 2e3be1d45371..7d436a5027cc 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -743,6 +743,14 @@  void clear_vm_flags(struct vm_area_struct *vma, unsigned long flags)
 	vma->vm_flags &= ~flags;
 }
 
+static inline
+void mod_vm_flags_nolock(struct vm_area_struct *vma,
+		  unsigned long set, unsigned long clear)
+{
+	vma->vm_flags |= set;
+	vma->vm_flags &= ~clear;
+}
+
 static inline
 void mod_vm_flags(struct vm_area_struct *vma,
 		  unsigned long set, unsigned long clear)