From patchwork Thu Jan 25 10:06:02 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jia-Ju Bai X-Patchwork-Id: 10183823 X-Patchwork-Delegate: herbert@gondor.apana.org.au Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 191ED60383 for ; Thu, 25 Jan 2018 10:01:50 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 06FC728A23 for ; Thu, 25 Jan 2018 10:01:50 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id EC8CC28A6D; Thu, 25 Jan 2018 10:01:49 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.0 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, FREEMAIL_FROM, RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 98BD628A23 for ; Thu, 25 Jan 2018 10:01:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751626AbeAYKBe (ORCPT ); Thu, 25 Jan 2018 05:01:34 -0500 Received: from mail-it0-f68.google.com ([209.85.214.68]:37290 "EHLO mail-it0-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751642AbeAYKBb (ORCPT ); Thu, 25 Jan 2018 05:01:31 -0500 Received: by mail-it0-f68.google.com with SMTP id q8so8701004itb.2; Thu, 25 Jan 2018 02:01:31 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id; bh=8URkHNlcoa4rHfFcRZZN4rkcuNZZk54ZrG8WeLln1qo=; b=Oc2YhpwfLPkFIoh2uAOkqkSV1I6ke2O3YN3eOGXR5vDjfcWoqrDp9MezoDf3mvhQg2 rovNfuC5lF84zfiDdB4POyOZt9OKuv+s+Jn4jTZ/5r1Igr/GCFlx61nSrgXr9OYwp5Ux pO9v1hNJ9fE9igl3w1YI5MVY8eCRweOPNNRzjPi0n7ISzKoK8+4rChbkfDrZDn0bPaoj Jl5PUoRV2+5D8HsMqb8bBe7tXhpe+9fMPcA2DP1noUWToeUoXQS7F6210TKiPZ5CvZzT P/ABG5/L7I57czbW0OiUJEd72HQYpugzT+rap0b2MPd5dyAP5qHYUQgV1Bpdln/l+s8O km2g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id; bh=8URkHNlcoa4rHfFcRZZN4rkcuNZZk54ZrG8WeLln1qo=; b=mDNyRalUCyC+2teXAl1xu/jESKJG9JgbSDkKZFK3XRg0yWI+EQsI2h++9Hn34tU4im MJ9Y62RcuA70cRMn6nF555hz7Ax7bRU2q3AUdosV30rBQ05l8mM8aA8qRTx6hjmOD2Ci 96WbwBFiU+aeU72T+KmyjGlpOD8/081bat5Iou4ZSoddAARJhF8+mrdUy0r2PJAxlpPj 6UgZ0UTEg4IUnnaZE0WOtl5IU/REh5ms0tUr4kXl1rMIecEHZ+pGNS1PWWkRBjMsX9HM tKlTarUs+kV48FC/T2gOVcsttki8J5Bulr3jKIRKfUkLdU50c7Sn4mHNOr8trlmwEmjt G1YA== X-Gm-Message-State: AKwxytfKGFhSuwpSte3N5baDASLuQYhtBqZ8L4hjz62iaXw5EYn5YxDp dz8XKfS8kfwd9pkIfank6dY= X-Google-Smtp-Source: AH8x2242DTw6wkhWHllvZwG/py/Eon1nzfFAyUVQ+PalZqg50yBXwe1yq4N4ZJcl513nLzdjy5M4Ww== X-Received: by 10.36.91.210 with SMTP id g201mr12338541itb.50.1516874491108; Thu, 25 Jan 2018 02:01:31 -0800 (PST) Received: from bai-oslab.tsinghua.edu.cn ([2402:f000:1:4413:9980:256a:8e6d:5903]) by smtp.gmail.com with ESMTPSA id v2sm1479613iob.72.2018.01.25.02.01.28 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 25 Jan 2018 02:01:30 -0800 (PST) From: Jia-Ju Bai To: herbert@gondor.apana.org.au, davem@davemloft.net Cc: linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org, Jia-Ju Bai Subject: [PATCH] crypto: crypto_user: Replace GFP_ATOMIC with GFP_KERNEL in crypto_report Date: Thu, 25 Jan 2018 18:06:02 +0800 Message-Id: <1516874762-12046-1-git-send-email-baijiaju1990@gmail.com> X-Mailer: git-send-email 1.7.9.5 Sender: linux-crypto-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-crypto@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP After checking all possible call chains to crypto_report here, my tool finds that crypto_report is never called in atomic context. And crypto_report calls crypto_alg_match which calls down_read, thus it proves again that crypto_report can call functions which may sleep. Thus GFP_ATOMIC is not necessary, and it can be replaced with GFP_KERNEL. This is found by a static analysis tool named DCNS written by myself. Signed-off-by: Jia-Ju Bai --- crypto/crypto_user.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/crypto/crypto_user.c b/crypto/crypto_user.c index 0dbe2be7..23baef1 100644 --- a/crypto/crypto_user.c +++ b/crypto/crypto_user.c @@ -271,7 +271,7 @@ static int crypto_report(struct sk_buff *in_skb, struct nlmsghdr *in_nlh, return -ENOENT; err = -ENOMEM; - skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC); + skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL); if (!skb) goto drop_alg;