| Message ID | 20221209021041.192835-2-wangkefeng.wang@huawei.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | mm: hwposion: support recovery from ksm_might_need_to_copy() | expand |
sorry, please ignore it, will resend. On 2022/12/9 10:10, Kefeng Wang wrote: > When the kernel copy a page from ksm_might_need_to_copy(), but runs > into an uncorrectable error, it will crash since poisoned page is > consumed by kernel, this is similar to Copy-on-write poison recovery, > When an error is detected during the page copy, return VM_FAULT_HWPOISON, > which help us to avoid system crash. Note, memory failure on a KSM > page will be skipped, but still call memory_failure_queue() to be > consistent with general memory failure process. > > Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> > --- > mm/ksm.c | 8 ++++++-- > mm/memory.c | 3 +++ > mm/swapfile.c | 2 +- > 3 files changed, 10 insertions(+), 3 deletions(-) > > diff --git a/mm/ksm.c b/mm/ksm.c > index f1e06b1d47f3..356e93b85287 100644 > --- a/mm/ksm.c > +++ b/mm/ksm.c > @@ -2629,8 +2629,12 @@ struct page *ksm_might_need_to_copy(struct page *page, > new_page = NULL; > } > if (new_page) { > - copy_user_highpage(new_page, page, address, vma); > - > + if (copy_mc_user_highpage(new_page, page, address, vma)) { > + put_page(new_page); > + new_page = ERR_PTR(-EHWPOISON); > + memory_failure_queue(page_to_pfn(page), 0); > + return new_page; > + } > SetPageDirty(new_page); > __SetPageUptodate(new_page); > __SetPageLocked(new_page); > diff --git a/mm/memory.c b/mm/memory.c > index 2615fa615be4..bb7b35e42297 100644 > --- a/mm/memory.c > +++ b/mm/memory.c > @@ -3840,6 +3840,9 @@ vm_fault_t do_swap_page(struct vm_fault *vmf) > if (unlikely(!page)) { > ret = VM_FAULT_OOM; > goto out_page; > + } els if (unlikely(PTR_ERR(page) == -EHWPOISON)) { > + ret = VM_FAULT_HWPOISON; > + goto out_page; > } > folio = page_folio(page); > > diff --git a/mm/swapfile.c b/mm/swapfile.c > index f670ffb7df7e..763ff6a8a576 100644 > --- a/mm/swapfile.c > +++ b/mm/swapfile.c > @@ -1767,7 +1767,7 @@ static int unuse_pte(struct vm_area_struct *vma, pmd_t *pmd, > > swapcache = page; > page = ksm_might_need_to_copy(page, vma, addr); > - if (unlikely(!page)) > + if (IS_ERR_OR_NULL(!page)) > return -ENOMEM; > > pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
diff --git a/mm/ksm.c b/mm/ksm.c index f1e06b1d47f3..356e93b85287 100644 --- a/mm/ksm.c +++ b/mm/ksm.c @@ -2629,8 +2629,12 @@ struct page *ksm_might_need_to_copy(struct page *page, new_page = NULL; } if (new_page) { - copy_user_highpage(new_page, page, address, vma); - + if (copy_mc_user_highpage(new_page, page, address, vma)) { + put_page(new_page); + new_page = ERR_PTR(-EHWPOISON); + memory_failure_queue(page_to_pfn(page), 0); + return new_page; + } SetPageDirty(new_page); __SetPageUptodate(new_page); __SetPageLocked(new_page); diff --git a/mm/memory.c b/mm/memory.c index 2615fa615be4..bb7b35e42297 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -3840,6 +3840,9 @@ vm_fault_t do_swap_page(struct vm_fault *vmf) if (unlikely(!page)) { ret = VM_FAULT_OOM; goto out_page; + } els if (unlikely(PTR_ERR(page) == -EHWPOISON)) { + ret = VM_FAULT_HWPOISON; + goto out_page; } folio = page_folio(page); diff --git a/mm/swapfile.c b/mm/swapfile.c index f670ffb7df7e..763ff6a8a576 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -1767,7 +1767,7 @@ static int unuse_pte(struct vm_area_struct *vma, pmd_t *pmd, swapcache = page; page = ksm_might_need_to_copy(page, vma, addr); - if (unlikely(!page)) + if (IS_ERR_OR_NULL(!page)) return -ENOMEM; pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
When the kernel copy a page from ksm_might_need_to_copy(), but runs into an uncorrectable error, it will crash since poisoned page is consumed by kernel, this is similar to Copy-on-write poison recovery, When an error is detected during the page copy, return VM_FAULT_HWPOISON, which help us to avoid system crash. Note, memory failure on a KSM page will be skipped, but still call memory_failure_queue() to be consistent with general memory failure process. Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> --- mm/ksm.c | 8 ++++++-- mm/memory.c | 3 +++ mm/swapfile.c | 2 +- 3 files changed, 10 insertions(+), 3 deletions(-)