+ mm-hwpoison-kill-procs-if-unmap-fails.patch added to mm-unstable branch

[Andrew Morton <akpm@linux-foundation.org>]

The patch titled
     Subject: mm, hwpoison: kill procs if unmap fails
has been added to the -mm mm-unstable branch.  Its filename is
     mm-hwpoison-kill-procs-if-unmap-fails.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-hwpoison-kill-procs-if-unmap-fails.patch

This patch will later appear in the mm-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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------------------------------------------------------
From: Miaohe Lin <linmiaohe@huawei.com>
Subject: mm, hwpoison: kill procs if unmap fails
Date: Thu, 18 Aug 2022 21:00:15 +0800

If try_to_unmap() fails, the hwpoisoned page still resides in the address
space of some processes.  We should kill these processes or the hwpoisoned
page might be consumed later.  collect_procs() is always called to collect
relevant processes now so they can be killed later if unmap fails.

Link: https://lkml.kernel.org/r/20220818130016.45313-6-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Naoya Horiguchi <naoya.horiguchi@nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/memory-failure.c |    9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

--- a/mm/memory-failure.c~mm-hwpoison-kill-procs-if-unmap-fails
+++ a/mm/memory-failure.c
@@ -1396,7 +1396,7 @@ static bool hwpoison_user_mappings(struc
 	struct address_space *mapping;
 	LIST_HEAD(tokill);
 	bool unmap_success;
-	int kill = 1, forcekill;
+	int forcekill;
 	bool mlocked = PageMlocked(hpage);
 
 	/*
@@ -1437,7 +1437,6 @@ static bool hwpoison_user_mappings(struc
 		if (page_mkclean(hpage)) {
 			SetPageDirty(hpage);
 		} else {
-			kill = 0;
 			ttu |= TTU_IGNORE_HWPOISON;
 			pr_info("%#lx: corrupted page was clean: dropped without side effects\n",
 				pfn);
@@ -1452,8 +1451,7 @@ static bool hwpoison_user_mappings(struc
 	 * Error handling: We ignore errors here because
 	 * there's nothing that can be done.
 	 */
-	if (kill)
-		collect_procs(hpage, &tokill, flags & MF_ACTION_REQUIRED);
+	collect_procs(hpage, &tokill, flags & MF_ACTION_REQUIRED);
 
 	if (PageHuge(hpage) && !PageAnon(hpage)) {
 		/*
@@ -1495,7 +1493,8 @@ static bool hwpoison_user_mappings(struc
 	 * use a more force-full uncatchable kill to prevent
 	 * any accesses to the poisoned memory.
 	 */
-	forcekill = PageDirty(hpage) || (flags & MF_MUST_KILL);
+	forcekill = PageDirty(hpage) || (flags & MF_MUST_KILL) ||
+		    !unmap_success;
 	kill_procs(&tokill, forcekill, !unmap_success, pfn, flags);
 
 	return unmap_success;
_

Patches currently in -mm which might be from linmiaohe@huawei.com are

mm-page_alloc-minor-clean-up-for-memmap_init_compound.patch
hugetlb_cgroup-remove-unneeded-nr_pages-0-check.patch
hugetlb_cgroup-hugetlbfs-use-helper-macro-sz_1kmg.patch
hugetlb_cgroup-remove-unneeded-return-value.patch
hugetlb_cgroup-use-helper-macro-numa_no_node.patch
hugetlb_cgroup-use-helper-for_each_hstate-and-hstate_index.patch
mm-hugetlb-fix-incorrect-update-of-max_huge_pages.patch
mm-hugetlb-fix-warn_onkobj-in-sysfs_create_group.patch
mm-hugetlb-fix-missing-call-to-restore_reserve_on_error.patch
mm-hugetlb_vmemmap-add-missing-smp_wmb-before-set_pte_at.patch
mm-hugetlb-fix-sysfs-group-leak-in-hugetlb_unregister_node.patch
mm-hugetlb-make-detecting-shared-pte-more-reliable.patch
mm-hwpoison-fix-page-refcnt-leaking-in-try_memory_failure_hugetlb.patch
mm-hwpoison-fix-page-refcnt-leaking-in-unpoison_memory.patch
mm-hwpoison-fix-extra-put_page-in-soft_offline_page.patch
mm-hwpoison-fix-possible-use-after-free-in-mf_dax_kill_procs.patch
mm-hwpoison-kill-procs-if-unmap-fails.patch
mm-hwpoison-avoid-trying-to-unpoison-reserved-page.patch