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 80BD7C77B61 for ; Mon, 24 Apr 2023 13:33:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232458AbjDXNd0 (ORCPT ); Mon, 24 Apr 2023 09:33:26 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59900 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232413AbjDXNdF (ORCPT ); Mon, 24 Apr 2023 09:33:05 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 64F277A9E for ; Mon, 24 Apr 2023 06:32:48 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id DD10662374 for ; Mon, 24 Apr 2023 13:32:10 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id F02D9C433EF; Mon, 24 Apr 2023 13:32:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1682343130; bh=KLV9dvTSLH+9DWbxDFOJcA1OUFgPOGVy3+1bSdM/77g=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Zm4iiXSHF8IhMU1LjM4aSqvHI/Dy/a3Bm1xxMGhLx5GUrHBRXxDoWmRHDpKdlkj1Y +fg+efjUbOe6JhMcFyaCmMJmC/jfIIG3TAJ1h61vDe57eAWvfBxaXzbvgw0Yly2E1i DsrPQ30wbWVoDrKx5o18vFmcT3A7ssL7Qeb8unc4= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Naoya Horiguchi , syzbot+07a218429c8d19b1fb25@syzkaller.appspotmail.com, Yang Shi , Miaohe Lin , Tetsuo Handa , Xu Yu , Andrew Morton Subject: [PATCH 6.2 088/110] mm/huge_memory.c: warn with pr_warn_ratelimited instead of VM_WARN_ON_ONCE_FOLIO Date: Mon, 24 Apr 2023 15:17:50 +0200 Message-Id: <20230424131139.809752609@linuxfoundation.org> X-Mailer: git-send-email 2.40.0 In-Reply-To: <20230424131136.142490414@linuxfoundation.org> References: <20230424131136.142490414@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Naoya Horiguchi commit 4737edbbdd4958ae29ca6a310a6a2fa4e0684b01 upstream. split_huge_page_to_list() WARNs when called for huge zero pages, which sounds to me too harsh because it does not imply a kernel bug, but just notifies the event to admins. On the other hand, this is considered as critical by syzkaller and makes its testing less efficient, which seems to me harmful. So replace the VM_WARN_ON_ONCE_FOLIO with pr_warn_ratelimited. Link: https://lkml.kernel.org/r/20230406082004.2185420-1-naoya.horiguchi@linux.dev Fixes: 478d134e9506 ("mm/huge_memory: do not overkill when splitting huge_zero_page") Signed-off-by: Naoya Horiguchi Reported-by: syzbot+07a218429c8d19b1fb25@syzkaller.appspotmail.com Link: https://lore.kernel.org/lkml/000000000000a6f34a05e6efcd01@google.com/ Reviewed-by: Yang Shi Cc: Miaohe Lin Cc: Tetsuo Handa Cc: Xu Yu Cc: Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman --- mm/huge_memory.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -2674,9 +2674,10 @@ int split_huge_page_to_list(struct page VM_BUG_ON_FOLIO(!folio_test_large(folio), folio); is_hzp = is_huge_zero_page(&folio->page); - VM_WARN_ON_ONCE_FOLIO(is_hzp, folio); - if (is_hzp) + if (is_hzp) { + pr_warn_ratelimited("Called split_huge_page for huge zero page\n"); return -EBUSY; + } if (folio_test_writeback(folio)) return -EBUSY;