Commit 681be068 authored by Tong Tiangen's avatar Tong Tiangen
Browse files

mm/hwpoison: return -EFAULT when copy fail in copy_mc_[user]_highpage() 

hulk inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I8M74H


CVE: NA

-------------------------------

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: default avatarTong Tiangen <tongtiangen@huawei.com>
parent 1a1eddb9

include/linux/highmem.h

+4 −4
Original line number Diff line number Diff line
@@ -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,

mm/khugepaged.c

+2 −2
Original line number Diff line number Diff line
@@ -797,7 +797,7 @@ 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;

		}
@@ -2050,7 +2050,7 @@ 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;

		}