The patch titled
Subject: mm/hwpoison: introduce copy_mc_highpage
has been added to the -mm mm-unstable branch. Its filename is
mm-hwpoison-introduce-copy_mc_highpage.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-hwpoison-introduce-copy_mc_highpage.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: Jiaqi Yan <jiaqiyan@xxxxxxxxxx>
Subject: mm/hwpoison: introduce copy_mc_highpage
Date: Sat, 4 Mar 2023 22:51:11 -0800
Similar to how copy_mc_user_highpage is implemented for copy_user_highpage
on #MC supported architecture, introduce the #MC handled version of
copy_highpage.
This helper has immediate usage when khugepaged wants to copy file-backed
memory pages and tolerate #MC.
Link: https://lkml.kernel.org/r/20230305065112.1932255-3-jiaqiyan@xxxxxxxxxx
Signed-off-by: Jiaqi Yan <jiaqiyan@xxxxxxxxxx>
Cc: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>
Cc: "Kirill A . Shutemov" <kirill@xxxxxxxxxxxxx>
Cc: Miaohe Lin <linmiaohe@xxxxxxxxxx>
Cc: Naoya Horiguchi <naoya.horiguchi@xxxxxxx>
Cc: Oscar Salvador <osalvador@xxxxxxx>
Cc: Tong Tiangen <tongtiangen@xxxxxxxxxx>
Cc: Tony Luck <tony.luck@xxxxxxxxx>
Cc: Yang Shi <shy828301@xxxxxxxxx>
Cc: David Stevens <stevensd@xxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
--- a/include/linux/highmem.h~mm-hwpoison-introduce-copy_mc_highpage
+++ a/include/linux/highmem.h
@@ -315,7 +315,29 @@ static inline void copy_user_highpage(st
#endif
+#ifndef __HAVE_ARCH_COPY_HIGHPAGE
+
+static inline void copy_highpage(struct page *to, struct page *from)
+{
+ char *vfrom, *vto;
+
+ vfrom = kmap_local_page(from);
+ vto = kmap_local_page(to);
+ copy_page(vto, vfrom);
+ kmsan_copy_page_meta(to, from);
+ kunmap_local(vto);
+ kunmap_local(vfrom);
+}
+
+#endif
+
#ifdef copy_mc_to_kernel
+/*
+ * If architecture supports machine check exception handling, define the
+ * #MC versions of copy_user_highpage and copy_highpage. They copy a memory
+ * page with #MC in source page (@from) handled, and return the number
+ * of bytes not copied if there was a #MC, otherwise 0 for success.
+ */
static inline int copy_mc_user_highpage(struct page *to, struct page *from,
unsigned long vaddr, struct vm_area_struct *vma)
{
@@ -332,29 +354,35 @@ static inline int copy_mc_user_highpage(
return ret;
}
-#else
-static inline int copy_mc_user_highpage(struct page *to, struct page *from,
- unsigned long vaddr, struct vm_area_struct *vma)
-{
- copy_user_highpage(to, from, vaddr, vma);
- return 0;
-}
-#endif
-
-#ifndef __HAVE_ARCH_COPY_HIGHPAGE
-static inline void copy_highpage(struct page *to, struct page *from)
+static inline int copy_mc_highpage(struct page *to, struct page *from)
{
+ unsigned long ret;
char *vfrom, *vto;
vfrom = kmap_local_page(from);
vto = kmap_local_page(to);
- copy_page(vto, vfrom);
- kmsan_copy_page_meta(to, from);
+ ret = copy_mc_to_kernel(vto, vfrom, PAGE_SIZE);
+ if (!ret)
+ kmsan_copy_page_meta(to, from);
kunmap_local(vto);
kunmap_local(vfrom);
+
+ return ret;
+}
+#else
+static inline int copy_mc_user_highpage(struct page *to, struct page *from,
+ unsigned long vaddr, struct vm_area_struct *vma)
+{
+ copy_user_highpage(to, from, vaddr, vma);
+ return 0;
}
+static inline int copy_mc_highpage(struct page *to, struct page *from)
+{
+ copy_highpage(to, from);
+ return 0;
+}
#endif
static inline void memcpy_page(struct page *dst_page, size_t dst_off,
_
Patches currently in -mm which might be from jiaqiyan@xxxxxxxxxx are
mm-khugepaged-recover-from-poisoned-anonymous-memory.patch
mm-hwpoison-introduce-copy_mc_highpage.patch
mm-khugepaged-recover-from-poisoned-file-backed-memory.patch
