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 83CFAC64ED8 for ; Sat, 18 Feb 2023 00:28:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229820AbjBRA2s (ORCPT ); Fri, 17 Feb 2023 19:28:48 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41652 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229510AbjBRA2q (ORCPT ); Fri, 17 Feb 2023 19:28:46 -0500 Received: from mail-yw1-x1149.google.com (mail-yw1-x1149.google.com [IPv6:2607:f8b0:4864:20::1149]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3CB2459B49 for ; Fri, 17 Feb 2023 16:28:45 -0800 (PST) Received: by mail-yw1-x1149.google.com with SMTP id 00721157ae682-536582abb72so22509327b3.5 for ; Fri, 17 Feb 2023 16:28:45 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=WRJSWRU8dQHXXhdXAbgeFtewLtYoHueyg1zV/lollrc=; b=JUkI+uUZUGikStVOrWOWfUFvkifZQjdvysrYVMcxjv1b2yQplxM71vw1fjhTzhEkxI BEohrL6MRF518g9B3YG2ljl8T7G93FwY6nToc+IVWoDTzVPkWMKdK99Fw+Y/07yhJ3P2 Pt0n2XoDP+p37aLwSJxXkZR/Jyh8LDLuXTOP46PclH0WaRZarQPsfJWYdmcsYTgivcxA V29rcePGsSV2Bm8JBI3cnvgY6VYwZ38Vy23D8uxt/hblg5U5P6fb6PnTeEwjCMXWB3jt Xt02v+X21m74LuwV377B2oYbsfLR/FpkRSgMkEe4zOTBZt33XomrJuA07ToJPeOqmC5B 2qvw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=WRJSWRU8dQHXXhdXAbgeFtewLtYoHueyg1zV/lollrc=; b=EFhDPtIx+Qrf0TIl/4WzadxlbNvCFb/DC0O4nJH6L5mqgMMaPMCn21myVcAXUcXeEh RfTkfQ4w7ZrSo/ssU1dGh9y1kn8UnUJPO1DHqQeVswx94rABzuihVLJGlinpHrXcNPQC PeCpgxQHiAT8W9gvJDNzTuEr/5R2ICjDzaRtIv6gBH7x0W9r+kQbAvw8SV98nWtx1jWu qsdSJgUQAgoJDcWIxAlOvNcDUOD4uCDa5D6iPiNVwz2WB1EWm1JsxsDfWRc8za4CD/wQ tBvokvaP006rcr7iYsbKHDSd72up7gagteZt3Lclwwx9S2DRWB5lLgMhpe9VLQUYvTBU R9WA== X-Gm-Message-State: AO0yUKXItu4v/sEEHBs8svAlKqTmYGHRsTmwIDH6YikvS8OTk9Cyvmmd usz/rZVcHt6xu/rt2Efoj330AKZlzMcJg5fS X-Google-Smtp-Source: AK7set/WjcZL+XrN64oa4iFWZNoLag2qFEizB65Q47paRVpixNGKzuLMD0K/0D4ZsPotwj/bHVSjyMfKhh7AGtfF X-Received: from jthoughton.c.googlers.com ([fda3:e722:ac3:cc00:14:4d90:c0a8:2a4f]) (user=jthoughton job=sendgmr) by 2002:a81:4981:0:b0:527:adb4:3297 with SMTP id w123-20020a814981000000b00527adb43297mr1507453ywa.161.1676680124408; Fri, 17 Feb 2023 16:28:44 -0800 (PST) Date: Sat, 18 Feb 2023 00:27:34 +0000 In-Reply-To: <20230218002819.1486479-1-jthoughton@google.com> Mime-Version: 1.0 References: <20230218002819.1486479-1-jthoughton@google.com> X-Mailer: git-send-email 2.39.2.637.g21b0678d19-goog Message-ID: <20230218002819.1486479-2-jthoughton@google.com> Subject: [PATCH v2 01/46] hugetlb: don't set PageUptodate for UFFDIO_CONTINUE From: James Houghton To: Mike Kravetz , Muchun Song , Peter Xu , Andrew Morton Cc: David Hildenbrand , David Rientjes , Axel Rasmussen , Mina Almasry , "Zach O'Keefe" , Manish Mishra , Naoya Horiguchi , "Dr . David Alan Gilbert" , "Matthew Wilcox (Oracle)" , Vlastimil Babka , Baolin Wang , Miaohe Lin , Yang Shi , Frank van der Linden , Jiaqi Yan , 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 If would be bad if we actually set PageUptodate with UFFDIO_CONTINUE; PageUptodate indicates that the page has been zeroed, and we don't want to give a non-zeroed page to the user. The reason this change is being made now is because UFFDIO_CONTINUEs on subpages definitely shouldn't set this page flag on the head page. Signed-off-by: James Houghton diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 07abcb6eb203..792cb2e67ce5 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -6256,7 +6256,16 @@ int hugetlb_mcopy_atomic_pte(struct mm_struct *dst_mm, * preceding stores to the page contents become visible before * the set_pte_at() write. */ - __folio_mark_uptodate(folio); + if (!is_continue) + __folio_mark_uptodate(folio); + else if (!folio_test_uptodate(folio)) { + /* + * This should never happen; HugeTLB pages are always Uptodate + * as soon as they are allocated. + */ + ret = -EFAULT; + goto out_release_nounlock; + } /* Add shared, newly allocated pages to the page cache. */ if (vm_shared && !is_continue) { -- 2.39.2.637.g21b0678d19-goog