From: Shengming Hu <shengminghu512@qq.com&gt;
Date: Tue, 23 Sep 2025 20:56:28 +0800
Subject: [PATCH] mm/memory-failure: Ensure collect_procs is retried when
&nbsp;unmap fails


In the memory_failure process, if collect_procs is not executed with the
flag set, the to_kill list may be empty. Even if there are pages that fail
to be unmapped, SIGKILL or SIGBUS cannot be sent to the process via
collect_procs.


This patch fixes the issue by re-executing collect_procs when the to_kill
list is empty and unmap fails. This collects processes with unmap failures
into the to_kill list, allowing SIGBUS or SIGKILL to terminate them in
subsequent code.


Signed-off-by: Shengming Hu <hu.shengming@zte.com.cn&gt;
---
&nbsp;mm/memory-failure.c | 5 ++++-
&nbsp;1 file changed, 4 insertions(+), 1 deletion(-)


diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index a24806bb8e82..8157823c7fb7 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -1600,9 +1600,12 @@ static bool hwpoison_user_mappings(struct folio *folio, struct page *p,
&nbsp;	collect_procs(folio, p, &amp;tokill, flags &amp; MF_ACTION_REQUIRED);
&nbsp;
&nbsp;	unmap_success = !unmap_poisoned_folio(folio, pfn, flags &amp; MF_MUST_KILL);
-	if (!unmap_success)
+	if (!unmap_success) {
&nbsp;		pr_err("%#lx: failed to unmap page (folio mapcount=%d)\n",
&nbsp;		&nbsp; &nbsp; &nbsp; &nbsp;pfn, folio_mapcount(folio));
+		if (list_empty(&amp;tokill))
+			collect_procs(folio, p, &amp;tokill, 1);
+	}
&nbsp;
&nbsp;	/*
&nbsp;	&nbsp;* try_to_unmap() might put mlocked page in lru cache, so call
--&nbsp;
2.25.1