This is a note to let you know that I've just added the patch titled
mm: call arch_swap_restore() from do_swap_page()
to the 5.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
mm-call-arch_swap_restore-from-do_swap_page.patch
and it can be found in the queue-5.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 6dca4ac6fc91fd41ea4d6c4511838d37f4e0eab2 Mon Sep 17 00:00:00 2001
From: Peter Collingbourne <pcc@xxxxxxxxxx>
Date: Mon, 22 May 2023 17:43:08 -0700
Subject: mm: call arch_swap_restore() from do_swap_page()
From: Peter Collingbourne <pcc@xxxxxxxxxx>
commit 6dca4ac6fc91fd41ea4d6c4511838d37f4e0eab2 upstream.
Commit c145e0b47c77 ("mm: streamline COW logic in do_swap_page()") moved
the call to swap_free() before the call to set_pte_at(), which meant that
the MTE tags could end up being freed before set_pte_at() had a chance to
restore them. Fix it by adding a call to the arch_swap_restore() hook
before the call to swap_free().
Link: https://lkml.kernel.org/r/20230523004312.1807357-2-pcc@xxxxxxxxxx
Link: https://linux-review.googlesource.com/id/I6470efa669e8bd2f841049b8c61020c510678965
Fixes: c145e0b47c77 ("mm: streamline COW logic in do_swap_page()")
Signed-off-by: Peter Collingbourne <pcc@xxxxxxxxxx>
Reported-by: Qun-wei Lin <Qun-wei.Lin@xxxxxxxxxxxx>
Closes: https://lore.kernel.org/all/5050805753ac469e8d727c797c2218a9d780d434.camel@xxxxxxxxxxxx/
Acked-by: David Hildenbrand <david@xxxxxxxxxx>
Acked-by: "Huang, Ying" <ying.huang@xxxxxxxxx>
Reviewed-by: Steven Price <steven.price@xxxxxxx>
Acked-by: Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx> [6.1+]
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
mm/memory.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/mm/memory.c b/mm/memory.c
index 0ae594703021..01f39e8144ef 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -3950,6 +3950,13 @@ vm_fault_t do_swap_page(struct vm_fault *vmf)
}
}
+ /*
+ * Some architectures may have to restore extra metadata to the page
+ * when reading from swap. This metadata may be indexed by swap entry
+ * so this must be called before swap_free().
+ */
+ arch_swap_restore(entry, folio);
+
/*
* Remove the swap entry and conditionally try to free up the swapcache.
* We're already holding a reference on the page but haven't mapped it
--
2.41.0
Patches currently in stable-queue which might be from pcc@xxxxxxxxxx are
queue-5.10/mm-call-arch_swap_restore-from-do_swap_page.patch
