[RFC PATCH 1/6] mm: Add a new mm flag for Copy-On-Write PTE table

From: Chih-En Lin
Date: Thu May 19 2022 - 14:30:23 EST


Add MMF_COW_PGTABLE flag to prepare the subsequent implementation of
copy-on-write for the page table.

Signed-off-by: Chih-En Lin <shiyn.lin@xxxxxxxxx>
---
include/linux/sched/coredump.h | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/include/linux/sched/coredump.h b/include/linux/sched/coredump.h
index 4d9e3a656875..19e9f2b71398 100644
--- a/include/linux/sched/coredump.h
+++ b/include/linux/sched/coredump.h
@@ -83,7 +83,10 @@ static inline int get_dumpable(struct mm_struct *mm)
#define MMF_HAS_PINNED 28 /* FOLL_PIN has run, never cleared */
#define MMF_DISABLE_THP_MASK (1 << MMF_DISABLE_THP)

+#define MMF_COW_PGTABLE 29
+#define MMF_COW_PGTABLE_MASK (1 << MMF_COW_PGTABLE)
+
#define MMF_INIT_MASK (MMF_DUMPABLE_MASK | MMF_DUMP_FILTER_MASK |\
- MMF_DISABLE_THP_MASK)
+ MMF_DISABLE_THP_MASK | MMF_COW_PGTABLE_MASK)

#endif /* _LINUX_SCHED_COREDUMP_H */
--
2.36.1