From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id CA9ACC433FE for ; Tue, 18 Oct 2022 20:01:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230026AbiJRUBh (ORCPT ); Tue, 18 Oct 2022 16:01:37 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46824 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229991AbiJRUBf (ORCPT ); Tue, 18 Oct 2022 16:01:35 -0400 Received: from mail-yw1-x114a.google.com (mail-yw1-x114a.google.com [IPv6:2607:f8b0:4864:20::114a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C22089D50A for ; Tue, 18 Oct 2022 13:01:34 -0700 (PDT) Received: by mail-yw1-x114a.google.com with SMTP id 00721157ae682-33dc888dc62so149550597b3.4 for ; Tue, 18 Oct 2022 13:01:34 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=cc:to:from:subject:message-id:mime-version:date:from:to:cc:subject :date:message-id:reply-to; bh=gWINlDuaY2L8iLCd06Hh2mBWo/vkOwHDew9Pwd1Mff0=; b=X2mLtVikXakn4hxHFaq5nvCpGMMIKzqg3vy+vui5ke+ILw0deOuNgwKM1a/6a2ucxr GyieO1X4Q+l8LPgHbxJqxtzLU7CCTsM6/dZV01yipi3H88nNem4nHrCjA7LHUpqWFqDz q57Rdzz1h2zTCUkTdI0psI+kPDK9nMq9apT8gRuofGMLElnRw5FE1tLG+yehmAXGbwqh 8W3RXe7c+5mFoVHOPi8KUjehorqwVUpCe1J7SBD8AJmpVZunyIjsMoyq497A8fbPX975 1+SODuMBIi1s1C45CO8wwl+K1HYsDdGhXJA3ngFwLFXZxiqiZUqMaG/cljW4TUcnPrEp ugSg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:from:subject:message-id:mime-version:date:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=gWINlDuaY2L8iLCd06Hh2mBWo/vkOwHDew9Pwd1Mff0=; b=mbCWUVcTflMe0XOiiriKB0Bd8XkqenERGzuY2GdX4/nwOT75UxeH68zTO/3IiFZd38 RzeTi8pB9DIvtDw1ak0Un759zUMo0hJGVosin9uYlcGkYVt0Yb0V8MnP1RdJNY/lvWQ8 ZgfZpULDDpORhFYNSBWec+7adoER7gj6QNFK+xaZ2VXMFWCFax7X+hieZpSU+bSpAE9g fuzNt/FYhL9DXGRXLg3SMTXomwqSwAeBcld3BsNiTPoojLBtfBCKBGN8zFXKZo6rDqhh +VDHpFJWV9pE0Tn1XDYW0U+r3ShGkRgUqt+ov7pUp7dfdEsrFuPj0EkLJpx9PhnG18n4 DmRQ== X-Gm-Message-State: ACrzQf2WBPgHQRG7bdeRnQBsOWr//ivR1WaIkO1H44BT7DitnDMvH+Kr qKVDxmiSmyPzLMDUgvzsF0K/c6/o8FEW8mGI X-Google-Smtp-Source: AMsMyM6JNgKvtwBSVr1HSV1EZHxot8IHHFatQXp/SbInzL9njtXvXY9HUEar18bQ2lUU3mkPCCiAScNVf/8WgioJ X-Received: from jthoughton.c.googlers.com ([fda3:e722:ac3:cc00:14:4d90:c0a8:2a4f]) (user=jthoughton job=sendgmr) by 2002:a0d:d5c8:0:b0:356:6d6c:7b83 with SMTP id x191-20020a0dd5c8000000b003566d6c7b83mr3920713ywd.439.1666123294095; Tue, 18 Oct 2022 13:01:34 -0700 (PDT) Date: Tue, 18 Oct 2022 20:01:25 +0000 Mime-Version: 1.0 X-Mailer: git-send-email 2.38.0.413.g74048e4d9e-goog Message-ID: <20221018200125.848471-1-jthoughton@google.com> Subject: [PATCH] hugetlbfs: don't delete error page from pagecache From: James Houghton To: Mike Kravetz , Muchun Song , Naoya Horiguchi , Miaohe Lin Cc: Andrew Morton , Yang Shi , Axel Rasmussen , linux-mm@kvack.org, linux-kernel@vger.kernel.org, James Houghton Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This change is very similar to the change that was made for shmem [1], and it solves the same problem but for HugeTLBFS instead. Currently, when poison is found in a HugeTLB page, the page is removed from the page cache. That means that attempting to map or read that hugepage in the future will result in a new hugepage being allocated instead of notifying the user that the page was poisoned. As [1] states, this is effectively memory corruption. The fix is to leave the page in the page cache. If the user attempts to use a poisoned HugeTLB page with a syscall, the syscall will fail with EIO, the same error code that shmem uses. For attempts to map the page, the thread will get a BUS_MCEERR_AR SIGBUS. [1]: commit a76054266661 ("mm: shmem: don't truncate page if memory failure happens") Signed-off-by: James Houghton --- fs/hugetlbfs/inode.c | 13 ++++++------- mm/hugetlb.c | 4 ++++ mm/memory-failure.c | 5 ++++- 3 files changed, 14 insertions(+), 8 deletions(-) diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c index fef5165b73a5..7f836f8f9db1 100644 --- a/fs/hugetlbfs/inode.c +++ b/fs/hugetlbfs/inode.c @@ -328,6 +328,12 @@ static ssize_t hugetlbfs_read_iter(struct kiocb *iocb, struct iov_iter *to) } else { unlock_page(page); + if (PageHWPoison(page)) { + put_page(page); + retval = -EIO; + break; + } + /* * We have the page, copy it to user space buffer. */ @@ -1111,13 +1117,6 @@ static int hugetlbfs_migrate_folio(struct address_space *mapping, static int hugetlbfs_error_remove_page(struct address_space *mapping, struct page *page) { - struct inode *inode = mapping->host; - pgoff_t index = page->index; - - hugetlb_delete_from_page_cache(page_folio(page)); - if (unlikely(hugetlb_unreserve_pages(inode, index, index + 1, 1))) - hugetlb_fix_reserve_counts(inode); - return 0; } diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 97896165fd3f..5120a9ccbf5b 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -6101,6 +6101,10 @@ int hugetlb_mcopy_atomic_pte(struct mm_struct *dst_mm, ptl = huge_pte_lock(h, dst_mm, dst_pte); + ret = -EIO; + if (PageHWPoison(page)) + goto out_release_unlock; + /* * We allow to overwrite a pte marker: consider when both MISSING|WP * registered, we firstly wr-protect a none pte which has no page cache diff --git a/mm/memory-failure.c b/mm/memory-failure.c index 145bb561ddb3..bead6bccc7f2 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -1080,6 +1080,7 @@ static int me_huge_page(struct page_state *ps, struct page *p) int res; struct page *hpage = compound_head(p); struct address_space *mapping; + bool extra_pins = false; if (!PageHuge(hpage)) return MF_DELAYED; @@ -1087,6 +1088,8 @@ static int me_huge_page(struct page_state *ps, struct page *p) mapping = page_mapping(hpage); if (mapping) { res = truncate_error_page(hpage, page_to_pfn(p), mapping); + /* The page is kept in page cache. */ + extra_pins = true; unlock_page(hpage); } else { unlock_page(hpage); @@ -1104,7 +1107,7 @@ static int me_huge_page(struct page_state *ps, struct page *p) } } - if (has_extra_refcount(ps, p, false)) + if (has_extra_refcount(ps, p, extra_pins)) res = MF_FAILED; return res; -- 2.38.0.413.g74048e4d9e-goog