The patch titled
Subject: mm: support poison recovery from copy_present_page()
has been added to the -mm mm-unstable branch. Its filename is
mm-support-poison-recovery-from-copy_present_page.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-support-poison-recovery-from-copy_present_page.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next via the mm-everything
branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there every 2-3 working days
------------------------------------------------------
From: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>
Subject: mm: support poison recovery from copy_present_page()
Date: Fri, 6 Sep 2024 10:42:01 +0800
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@xxxxxxxxxx
Signed-off-by: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>
Reviewed-by: Jane Chu <jane.chu@xxxxxxxxxx>
Cc: David Hildenbrand <david@xxxxxxxxxx>
Cc: Jiaqi Yan <jiaqiyan@xxxxxxxxxx>
Cc: Miaohe Lin <linmiaohe@xxxxxxxxxx>
Cc: Naoya Horiguchi <nao.horiguchi@xxxxxxxxx>
Cc: Tony Luck <tony.luck@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/memory.c | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)
--- a/mm/memory.c~mm-support-poison-recovery-from-copy_present_page
+++ a/mm/memory.c
@@ -926,8 +926,11 @@ copy_present_page(struct vm_area_struct
* 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);
_
Patches currently in -mm which might be from wangkefeng.wang@xxxxxxxxxx are
mm-migrate_device-convert-to-migrate_device_coherent_folio.patch
mm-migrate_device-use-a-folio-in-migrate_device_range.patch
mm-migrate_device-use-more-folio-in-migrate_device_unmap.patch
mm-migrate_device-use-more-folio-in-migrate_device_finalize.patch
mm-remove-isolate_lru_page.patch
mm-remove-isolate_lru_page-fix.patch
mm-remove-putback_lru_page.patch
mm-migrate-remove-unused-includes.patch
mm-support-poison-recovery-from-do_cow_fault.patch
mm-support-poison-recovery-from-copy_present_page.patch
