linux-kernel - [RFC PATCH] mm: memory-failure: add missing set_mce_nospec() for memory

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Date:   Tue, 4 Jul 2023 20:19:48 +0800
From:   Miaohe Lin <linmiaohe@...wei.com>
To:     <akpm@...ux-foundation.org>, <naoya.horiguchi@....com>
CC:     <linux-mm@...ck.org>, <linux-kernel@...r.kernel.org>,
        <linmiaohe@...wei.com>
Subject: [RFC PATCH] mm: memory-failure: add missing set_mce_nospec() for memory_failure()

If memory_failure() succeeds to hwpoison a page, the set_mce_nospec() is
expected to be called to prevent speculative access to the page by marking
it not-present. Add such missing call to set_mce_nospec() in async memory
failure handling scene.

Signed-off-by: Miaohe Lin <linmiaohe@...wei.com>
---
 mm/memory-failure.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index e245191e6b04..c7f88c4042d4 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -63,6 +63,7 @@
 #include <linux/pagewalk.h>
 #include <linux/shmem_fs.h>
 #include <linux/sysctl.h>
+#include <linux/set_memory.h>
 #include "swap.h"
 #include "internal.h"
 #include "ras/ras_event.h"
@@ -2407,7 +2408,9 @@ static void memory_failure_work_func(struct work_struct *work)
 		if (entry.flags & MF_SOFT_OFFLINE)
 			soft_offline_page(entry.pfn, entry.flags);
 		else
-			memory_failure(entry.pfn, entry.flags);
+			if (!memory_failure(entry.pfn, entry.flags))
+				if (!entry.flags & MF_SW_SIMULATED)
+					set_mce_nospec(entry.pfn);
 	}
 }
 
-- 
2.33.0