From 658be46520ce480a44fe405730a1725166298f27 Mon Sep 17 00:00:00 2001
From: Kefeng Wang <wangkefeng.wang@huawei.com>
Date: Fri, 6 Sep 2024 10:42:01 +0800
Subject: [PATCH] mm: support poison recovery from copy_present_page()
Similar to other poison recovery, use copy_mc_user_highpage() to avoid
potentially kernel panic during copy page in copy_present_page() from
fork, once copy failed due to hwpoison in source page, we need to break
out of copy in copy_pte_range() and release prealloc folio, so
copy_mc_user_highpage() is moved ahead before set *prealloc to NULL.
Link: https://lkml.kernel.org/r/20240906024201.1214712-3-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Reviewed-by: Jane Chu <jane.chu@oracle.com>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jiaqi Yan <jiaqiyan@google.com>
Cc: Naoya Horiguchi <nao.horiguchi@gmail.com>
Cc: Tony Luck <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
mm/memory.c | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)
diff --git a/mm/memory.c b/mm/memory.c
index 64421ea5a4036..cca3d29074399 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -926,8 +926,11 @@ copy_present_page(struct vm_area_struct *dst_vma, struct vm_area_struct *src_vma
* We have a prealloc page, all good! Take it
* over and copy the page & arm it.
*/
+
+ if (copy_mc_user_highpage(&new_folio->page, page, addr, src_vma))
+ return -EHWPOISON;
+
*prealloc = NULL;
- copy_user_highpage(&new_folio->page, page, addr, src_vma);
__folio_mark_uptodate(new_folio);
folio_add_new_anon_rmap(new_folio, dst_vma, addr, RMAP_EXCLUSIVE);
folio_add_lru_vma(new_folio, dst_vma);
@@ -1166,8 +1169,9 @@ again:
/*
* If we need a pre-allocated page for this pte, drop the
* locks, allocate, and try again.
+ * If copy failed due to hwpoison in source page, break out.
*/
- if (unlikely(ret == -EAGAIN))
+ if (unlikely(ret == -EAGAIN || ret == -EHWPOISON))
break;
if (unlikely(prealloc)) {
/*
@@ -1197,7 +1201,7 @@ again:
goto out;
}
entry.val = 0;
- } else if (ret == -EBUSY) {
+ } else if (ret == -EBUSY || unlikely(ret == -EHWPOISON)) {
goto out;
} else if (ret == -EAGAIN) {
prealloc = folio_prealloc(src_mm, src_vma, addr, false);
--
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