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 X-Spam-Level: X-Spam-Status: No, score=-16.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 853E7C433E0 for ; Wed, 20 Jan 2021 14:36:40 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 157D9221FF for ; Wed, 20 Jan 2021 14:36:40 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 157D9221FF Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id A4D7D6B0008; Wed, 20 Jan 2021 09:36:39 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 9FDBD6B000E; Wed, 20 Jan 2021 09:36:39 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 93AB86B0010; Wed, 20 Jan 2021 09:36:39 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0134.hostedemail.com [216.40.44.134]) by kanga.kvack.org (Postfix) with ESMTP id 7DF116B0008 for ; Wed, 20 Jan 2021 09:36:39 -0500 (EST) Received: from smtpin29.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id 43DA7180AD82F for ; Wed, 20 Jan 2021 14:36:39 +0000 (UTC) X-FDA: 77726404518.29.mom20_330933b2755b Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin29.hostedemail.com (Postfix) with ESMTP id 181AD18086CC0 for ; Wed, 20 Jan 2021 14:36:39 +0000 (UTC) X-HE-Tag: mom20_330933b2755b X-Filterd-Recvd-Size: 3434 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf33.hostedemail.com (Postfix) with ESMTP for ; Wed, 20 Jan 2021 14:36:38 +0000 (UTC) Received: by mail.kernel.org (Postfix) with ESMTPSA id A8FE22245C; Wed, 20 Jan 2021 14:36:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1611153397; bh=gIx6Byc8LjKVM2fxtZc3MbFvHCR2ATctdI9B+bQjgWA=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=fkSuyQs8KSB/KtNGKxIrVGEifND+44NVHwWeNayUTerkL80A0LoOgfjJoX2lY7xWu Jjb0CRRjYi0vPSmrA0VC/ZpTt8zoq0WTd+lrjb801soxlOecDQ6uQ3nt2LdqUqR2Pz bQnYfuUJFtLVjBACmcPG3CyitoIgoj6VftlYiMfceXHsyoeFEe0mxJbGhBaS7OwLmp ApXp3/YG2LzIogMHRT16xfteWpqpp3FsMf8MNpT+UIap3qFkiwGt++1GlmynUQ8Q7J fU+LNDLUQmKQKbWsLyJAC7qBYCsxZwH1in5DlB9M8LwYwF3CpeXMoS3pMSoKF+ufCD iW7tB/rQMxsyw== Date: Wed, 20 Jan 2021 16:36:31 +0200 From: Jarkko Sakkinen To: Tianjia Zhang Cc: Thomas Gleixner , Ingo Molnar , Borislav Petkov , "H. Peter Anvin" , Andrew Morton , Shuah Khan , haitao.huang@intel.com, Kai Huang , x86@kernel.org, linux-sgx@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-kselftest@vger.kernel.org, Jia Zhang Subject: Re: [PATCH] x86/sgx: Fix free_cnt counting logic in epc section Message-ID: References: <20210118133347.99158-1-tianjia.zhang@linux.alibaba.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210118133347.99158-1-tianjia.zhang@linux.alibaba.com> X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Mon, Jan 18, 2021 at 09:33:47PM +0800, Tianjia Zhang wrote: > Increase `section->free_cnt` in sgx_sanitize_section() is > more reasonable, which is called in ksgxd kernel thread, > instead of assigning it to epc section pages number at > initialization. Although this is unlikely to fail, these > pages cannot be allocated after initialization, and which > need to be reset by ksgxd. > > Reported-by: Jia Zhang > Signed-off-by: Tianjia Zhang There is nothing broken in the logic. Convince me otherwise. I.e. what is exactly broken, and how? /Jarkko > --- > arch/x86/kernel/cpu/sgx/main.c | 6 +++--- > 1 file changed, 3 insertions(+), 3 deletions(-) > > diff --git a/arch/x86/kernel/cpu/sgx/main.c b/arch/x86/kernel/cpu/sgx/main.c > index c519fc5f6948..9e9a3cf7c00b 100644 > --- a/arch/x86/kernel/cpu/sgx/main.c > +++ b/arch/x86/kernel/cpu/sgx/main.c > @@ -48,9 +48,10 @@ static void sgx_sanitize_section(struct sgx_epc_section *section) > struct sgx_epc_page, list); > > ret = __eremove(sgx_get_epc_virt_addr(page)); > - if (!ret) > + if (!ret) { > list_move(&page->list, §ion->page_list); > - else > + section->free_cnt += 1; > + } else > list_move_tail(&page->list, &dirty); > > spin_unlock(§ion->lock); > @@ -646,7 +647,6 @@ static bool __init sgx_setup_epc_section(u64 phys_addr, u64 size, > list_add_tail(§ion->pages[i].list, §ion->init_laundry_list); > } > > - section->free_cnt = nr_pages; > return true; > } > > -- > 2.19.1.3.ge56e4f7 > >