Commit f034a32a authored by Kefeng Wang's avatar Kefeng Wang Committed by Tong Tiangen
Browse files

mm: support poison recovery from copy_present_page() 

mainline inclusion
from mainline-v6.11-rc6
commit 658be46520ce480a44fe405730a1725166298f27
category: feature
bugzilla: https://gitee.com/src-openeuler/kernel/issues/IATH6V
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=658be46520ce480a44fe405730a1725166298f27

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

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@huawei.com


Signed-off-by: default avatarKefeng Wang <wangkefeng.wang@huawei.com>
Reviewed-by: default avatarJane Chu <jane.chu@oracle.com>
Reviewed-by: default avatarMiaohe Lin <linmiaohe@huawei.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jiaqi Yan <jiaqiyan@google.com>
Cc: Naoya Horiguchi <nao.horiguchi@gmail.com>
Cc: Tony Luck <tony.luck@intel.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarTong Tiangen <tongtiangen@huawei.com>
parent 4676985c

mm/memory.c

+7 −3
Original line number Diff line number Diff line
@@ -920,8 +920,11 @@ copy_present_page(struct vm_area_struct *dst_vma, struct vm_area_struct *src_vma 
	 * 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);
@@ -1161,8 +1164,9 @@ copy_pte_range(struct vm_area_struct *dst_vma, struct vm_area_struct *src_vma, 
		/*

		 * 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)) {

			/*
@@ -1192,7 +1196,7 @@ copy_pte_range(struct vm_area_struct *dst_vma, struct vm_area_struct *src_vma, 
			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);