| Message ID | 20240528085915.1955987-4-tongtiangen@huawei.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | arm64: add ARCH_HAS_COPY_MC support | expand |
On Tue, 28 May 2024 16:59:12 +0800 Tong Tiangen <tongtiangen@huawei.com> wrote: > If hardware errors are encountered during page copying, returning the bytes > not copied is not meaningful, and the caller cannot do any processing on > the remaining data. Returning -EFAULT is more reasonable, which represents > a hardware error encountered during the copying. > > Signed-off-by: Tong Tiangen <tongtiangen@huawei.com> LGTM Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> > --- > include/linux/highmem.h | 8 ++++---- > mm/khugepaged.c | 4 ++-- > 2 files changed, 6 insertions(+), 6 deletions(-) > > diff --git a/include/linux/highmem.h b/include/linux/highmem.h > index 00341b56d291..64a567d5ad6f 100644 > --- a/include/linux/highmem.h > +++ b/include/linux/highmem.h > @@ -335,8 +335,8 @@ static inline void copy_highpage(struct page *to, struct page *from) > /* > * 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. > + * page with #MC in source page (@from) handled, and return -EFAULT 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) > @@ -352,7 +352,7 @@ static inline int copy_mc_user_highpage(struct page *to, struct page *from, > kunmap_local(vto); > kunmap_local(vfrom); > > - return ret; > + return ret ? -EFAULT : 0; > } > > static inline int copy_mc_highpage(struct page *to, struct page *from) > @@ -368,7 +368,7 @@ static inline int copy_mc_highpage(struct page *to, struct page *from) > kunmap_local(vto); > kunmap_local(vfrom); > > - return ret; > + return ret ? -EFAULT : 0; > } > #else > static inline int copy_mc_user_highpage(struct page *to, struct page *from, > diff --git a/mm/khugepaged.c b/mm/khugepaged.c > index 774a97e6e2da..cce838e85967 100644 > --- a/mm/khugepaged.c > +++ b/mm/khugepaged.c > @@ -798,7 +798,7 @@ static int __collapse_huge_page_copy(pte_t *pte, struct folio *folio, > continue; > } > src_page = pte_page(pteval); > - if (copy_mc_user_highpage(page, src_page, src_addr, vma) > 0) { > + if (copy_mc_user_highpage(page, src_page, src_addr, vma)) { > result = SCAN_COPY_MC; > break; > } > @@ -2042,7 +2042,7 @@ static int collapse_file(struct mm_struct *mm, unsigned long addr, > index++; > dst++; > } > - if (copy_mc_highpage(dst, folio_page(folio, 0)) > 0) { > + if (copy_mc_highpage(dst, folio_page(folio, 0))) { > result = SCAN_COPY_MC; > goto rollback; > }
diff --git a/include/linux/highmem.h b/include/linux/highmem.h index 00341b56d291..64a567d5ad6f 100644 --- a/include/linux/highmem.h +++ b/include/linux/highmem.h @@ -335,8 +335,8 @@ static inline void copy_highpage(struct page *to, struct page *from) /* * 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. + * page with #MC in source page (@from) handled, and return -EFAULT 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) @@ -352,7 +352,7 @@ static inline int copy_mc_user_highpage(struct page *to, struct page *from, kunmap_local(vto); kunmap_local(vfrom); - return ret; + return ret ? -EFAULT : 0; } static inline int copy_mc_highpage(struct page *to, struct page *from) @@ -368,7 +368,7 @@ static inline int copy_mc_highpage(struct page *to, struct page *from) kunmap_local(vto); kunmap_local(vfrom); - return ret; + return ret ? -EFAULT : 0; } #else static inline int copy_mc_user_highpage(struct page *to, struct page *from, diff --git a/mm/khugepaged.c b/mm/khugepaged.c index 774a97e6e2da..cce838e85967 100644 --- a/mm/khugepaged.c +++ b/mm/khugepaged.c @@ -798,7 +798,7 @@ static int __collapse_huge_page_copy(pte_t *pte, struct folio *folio, continue; } src_page = pte_page(pteval); - if (copy_mc_user_highpage(page, src_page, src_addr, vma) > 0) { + if (copy_mc_user_highpage(page, src_page, src_addr, vma)) { result = SCAN_COPY_MC; break; } @@ -2042,7 +2042,7 @@ static int collapse_file(struct mm_struct *mm, unsigned long addr, index++; dst++; } - if (copy_mc_highpage(dst, folio_page(folio, 0)) > 0) { + if (copy_mc_highpage(dst, folio_page(folio, 0))) { result = SCAN_COPY_MC; goto rollback; }
If hardware errors are encountered during page copying, returning the bytes not copied is not meaningful, and the caller cannot do any processing on the remaining data. Returning -EFAULT is more reasonable, which represents a hardware error encountered during the copying. Signed-off-by: Tong Tiangen <tongtiangen@huawei.com> --- include/linux/highmem.h | 8 ++++---- mm/khugepaged.c | 4 ++-- 2 files changed, 6 insertions(+), 6 deletions(-)