Commit 0792a4a6 authored by Miaohe Lin's avatar Miaohe Lin Committed by Andrew Morton
Browse files

mm, hwpoison: kill procs if unmap fails 

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.

[linmiaohe@huawei.com: v2]
  Link: https://lkml.kernel.org/r/20220823032346.4260-6-linmiaohe@huawei.com
Link: https://lkml.kernel.org/r/20220818130016.45313-6-linmiaohe@huawei.com


Signed-off-by: default avatarMiaohe Lin <linmiaohe@huawei.com>
Acked-by: default avatarNaoya Horiguchi <naoya.horiguchi@nec.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 54f9555d

mm/memory-failure.c

+4 −8
Original line number Diff line number Diff line
@@ -1397,7 +1397,7 @@ static bool hwpoison_user_mappings(struct page *p, unsigned long pfn, 
	struct address_space *mapping;

	LIST_HEAD(tokill);

	bool unmap_success;

	int kill = 1, forcekill;

	int forcekill;

	bool mlocked = PageMlocked(hpage);



	/*
@@ -1438,7 +1438,6 @@ static bool hwpoison_user_mappings(struct page *p, unsigned long pfn, 
		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);
@@ -1449,11 +1448,7 @@ static bool hwpoison_user_mappings(struct page *p, unsigned long pfn, 
	 * First collect all the processes that have the page

	 * mapped in dirty form.  This has to be done before try_to_unmap,

	 * because ttu takes the rmap data structures down.

	 *

	 * Error handling: We ignore errors here because

	 * there's nothing that can be done.

	 */

	if (kill)

	collect_procs(hpage, &tokill, flags & MF_ACTION_REQUIRED);



	if (PageHuge(hpage) && !PageAnon(hpage)) {
@@ -1496,7 +1491,8 @@ static bool hwpoison_user_mappings(struct page *p, unsigned long pfn, 
	 * 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;