On Thu, Jan 26, 2023 at 11:17:09AM +0200, Mike Rapoport wrote:
On Wed, Jan 25, 2023 at 12:38:46AM -0800, Suren Baghdasaryan wrote:
vm_flags are among VMA attributes which affect decisions like VMA merging and splitting. Therefore all vm_flags modifications are performed after taking exclusive mmap_lock to prevent vm_flags updates racing with such operations. Introduce modifier functions for vm_flags to be used whenever flags are updated. This way we can better check and control correct locking behavior during these updates.
Signed-off-by: Suren Baghdasaryan surenb@google.com
include/linux/mm.h | 37 +++++++++++++++++++++++++++++++++++++ include/linux/mm_types.h | 8 +++++++- 2 files changed, 44 insertions(+), 1 deletion(-)
diff --git a/include/linux/mm.h b/include/linux/mm.h index c2f62bdce134..b71f2809caac 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -627,6 +627,43 @@ static inline void vma_init(struct vm_area_struct *vma, struct mm_struct *mm) INIT_LIST_HEAD(&vma->anon_vma_chain); }
+/* Use when VMA is not part of the VMA tree and needs no locking */ +static inline void init_vm_flags(struct vm_area_struct *vma,
unsigned long flags)I'd suggest to make it vm_flags_init() etc.
Thinking more about it, it will be even clearer to name these vma_flags_xyz()
Except that
Acked-by: Mike Rapoport (IBM) rppt@kernel.org
-- Sincerely yours, Mike.