The patch titled
Subject: mm/swapfile: fix wrong swap entry type for hwpoisoned swapcache page
has been added to the -mm mm-hotfixes-unstable branch. Its filename is
mm-swapfile-fix-wrong-swap-entry-type-for-hwpoisoned-swapcache-page.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-swapfile-fix-wrong-swap-entry-type-for-hwpoisoned-swapcache-page.patch
This patch will later appear in the mm-hotfixes-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Miaohe Lin <linmiaohe@xxxxxxxxxx>
Subject: mm/swapfile: fix wrong swap entry type for hwpoisoned swapcache page
Date: Thu, 27 Jul 2023 19:56:40 +0800
Patch series "A few fixup patches for mm", v2.
This series contains a few fixup patches to fix potential unexpected
return value, fix wrong swap entry type for hwpoisoned swapcache page and
so on. More details can be found in the respective changelogs.
This patch (of 4):
Hwpoisoned dirty swap cache page is kept in the swap cache and there's
simple interception code in do_swap_page() to catch it. But when trying
to swapoff, unuse_pte() will wrongly install a general sense of "future
accesses are invalid" swap entry for hwpoisoned swap cache page due to
unaware of such type of page. The user will receive SIGBUS signal without
expected BUS_MCEERR_AR payload. BTW, typo 'hwposioned' is fixed.
Link: https://lkml.kernel.org/r/20230727115643.639741-1-linmiaohe@xxxxxxxxxx
Link: https://lkml.kernel.org/r/20230727115643.639741-2-linmiaohe@xxxxxxxxxx
Fixes: 6b970599e807 ("mm: hwpoison: support recovery from ksm_might_need_to_copy()")
Signed-off-by: Miaohe Lin <linmiaohe@xxxxxxxxxx>
Cc: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>
Cc: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Cc: Naoya Horiguchi <naoya.horiguchi@xxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/ksm.c | 2 ++
mm/swapfile.c | 8 ++++----
2 files changed, 6 insertions(+), 4 deletions(-)
--- a/mm/ksm.c~mm-swapfile-fix-wrong-swap-entry-type-for-hwpoisoned-swapcache-page
+++ a/mm/ksm.c
@@ -2784,6 +2784,8 @@ struct page *ksm_might_need_to_copy(stru
anon_vma->root == vma->anon_vma->root) {
return page; /* still no need to copy it */
}
+ if (PageHWPoison(page))
+ return ERR_PTR(-EHWPOISON);
if (!PageUptodate(page))
return page; /* let do_swap_page report the error */
--- a/mm/swapfile.c~mm-swapfile-fix-wrong-swap-entry-type-for-hwpoisoned-swapcache-page
+++ a/mm/swapfile.c
@@ -1746,7 +1746,7 @@ static int unuse_pte(struct vm_area_stru
struct page *swapcache;
spinlock_t *ptl;
pte_t *pte, new_pte, old_pte;
- bool hwposioned = false;
+ bool hwpoisoned = PageHWPoison(page);
int ret = 1;
swapcache = page;
@@ -1754,7 +1754,7 @@ static int unuse_pte(struct vm_area_stru
if (unlikely(!page))
return -ENOMEM;
else if (unlikely(PTR_ERR(page) == -EHWPOISON))
- hwposioned = true;
+ hwpoisoned = true;
pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
if (unlikely(!pte || !pte_same_as_swp(ptep_get(pte),
@@ -1765,11 +1765,11 @@ static int unuse_pte(struct vm_area_stru
old_pte = ptep_get(pte);
- if (unlikely(hwposioned || !PageUptodate(page))) {
+ if (unlikely(hwpoisoned || !PageUptodate(page))) {
swp_entry_t swp_entry;
dec_mm_counter(vma->vm_mm, MM_SWAPENTS);
- if (hwposioned) {
+ if (hwpoisoned) {
swp_entry = make_hwpoison_entry(swapcache);
page = swapcache;
} else {
_
Patches currently in -mm which might be from linmiaohe@xxxxxxxxxx are
mm-swapfile-fix-wrong-swap-entry-type-for-hwpoisoned-swapcache-page.patch
mm-memory-failure-fix-potential-unexpected-return-value-from-unpoison_memory.patch
mm-memory-failure-avoid-false-hwpoison-page-mapped-error-info.patch
mm-memory-failure-add-pageoffline-check.patch
mm-mm_initc-update-obsolete-comment-in-get_pfn_range_for_nid.patch
mm-memory-failure-fix-unexpected-return-value-in-soft_offline_page.patch
mm-memory-failure-fix-potential-page-refcnt-leak-in-memory_failure.patch
mm-memory-failure-remove-unneeded-page-state-check-in-shake_page.patch
memory-tier-use-helper-function-destroy_memory_type.patch
mm-memory-failure-remove-unneeded-inline-annotation.patch
mm-mm_initc-remove-obsolete-macro-hash_small.patch
mm-page_alloc-avoid-false-page-outside-zone-error-info.patch
memory-tier-rename-destroy_memory_type-to-put_memory_type.patch
mm-remove-obsolete-comment-above-struct-per_cpu_pages.patch
mm-memcg-minor-cleanup-for-mem_cgroup_id_max.patch
mm-memory-failure-remove-unneeded-pagehuge-check.patch
mm-memory-failure-ensure-moving-hwpoison-flag-to-the-raw-error-pages.patch
mm-memory-failure-dont-account-hwpoison_filter-filtered-pages.patch
mm-memory-failure-use-local-variable-huge-to-check-hugetlb-page.patch
mm-memory-failure-remove-unneeded-header-files.patch
mm-memory-failure-minor-cleanup-for-comments-and-codestyle.patch
mm-memory-failure-fetch-compound-head-after-extra-page-refcnt-is-held.patch
mm-memory-failure-fix-race-window-when-trying-to-get-hugetlb-folio.patch
mm-huge_memory-use-rmap_none-when-calling-page_add_anon_rmap.patch
mm-memcg-fix-obsolete-comment-above-mem_cgroup_max_reclaim_loops.patch
mm-memcg-minor-cleanup-for-mc_handle_present_pte.patch
memory-tier-use-helper-macro-__attr_rw.patch
mm-fix-obsolete-function-name-above-debug_pagealloc_enabled_static.patch
mm-mprotect-fix-obsolete-function-name-in-change_pte_range.patch
mm-memcg-fix-obsolete-function-name-in-mem_cgroup_protection.patch
