hulk inclusion category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I9GCZS CVE: NA
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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(-)
diff --git a/include/linux/highmem.h b/include/linux/highmem.h index 75607d4ba26c..b02a8570609d 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 107608bc2ada..0b8636537383 100644 --- a/mm/khugepaged.c +++ b/mm/khugepaged.c @@ -804,7 +804,7 @@ static int __collapse_huge_page_copy(pte_t *pte, continue; } src_page = pte_page(pteval); - if (copy_mc_user_highpage(page, src_page, _address, vma) > 0) { + if (copy_mc_user_highpage(page, src_page, _address, vma)) { result = SCAN_COPY_MC; break; } @@ -2071,7 +2071,7 @@ static int collapse_file(struct mm_struct *mm, unsigned long addr, clear_highpage(hpage + (index % HPAGE_PMD_NR)); index++; } - if (copy_mc_highpage(hpage + (page->index % HPAGE_PMD_NR), page) > 0) { + if (copy_mc_highpage(hpage + (page->index % HPAGE_PMD_NR), page)) { result = SCAN_COPY_MC; goto rollback; }