diff mbox series

[RFC,19/28] mm: disallow do_swap_page to handle page faults under VMA lock

Message ID 20220829212531.3184856-20-surenb@google.com (mailing list archive)
State New, archived
Headers show
Series per-VMA locks proposal | expand

Commit Message

Suren Baghdasaryan Aug. 29, 2022, 9:25 p.m. UTC 
Due to the possibility of do_swap_page dropping mmap_lock, abort fault
handling under VMA lock and retry holding mmap_lock. This can be handled
more gracefully in the future.

Signed-off-by: Suren Baghdasaryan <surenb@google.com>
---
 mm/memory.c | 5 +++++
 1 file changed, 5 insertions(+)
diff mbox series

Patch

diff --git a/mm/memory.c b/mm/memory.c
index 9ac9944e8c62..29d2f49f922a 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -3738,6 +3738,11 @@  vm_fault_t do_swap_page(struct vm_fault *vmf)
 	vm_fault_t ret = 0;
 	void *shadow = NULL;
 
+	if (vmf->flags & FAULT_FLAG_VMA_LOCK) {
+		ret = VM_FAULT_RETRY;
+		goto out;
+	}
+
 	if (!pte_unmap_same(vmf))
 		goto out;