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 F2E0BC433EF for ; Mon, 25 Apr 2022 17:58:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244182AbiDYSBQ (ORCPT ); Mon, 25 Apr 2022 14:01:16 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59304 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S244167AbiDYSBJ (ORCPT ); Mon, 25 Apr 2022 14:01:09 -0400 Received: from mail-ed1-x52c.google.com (mail-ed1-x52c.google.com [IPv6:2a00:1450:4864:20::52c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6A2FC286CE for ; Mon, 25 Apr 2022 10:58:04 -0700 (PDT) Received: by mail-ed1-x52c.google.com with SMTP id z19so6134354edx.9 for ; Mon, 25 Apr 2022 10:58:04 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=6ogzFF1vidBXb8qUr8gbdeuYvvr4G0L7hay7vGN5jrk=; b=fQk1z1BqeH70BndD2TZKd5xfNwDkTjv0pCOIscV3w0xlpv4EByQ3g0nDFXzpYuYmaT RvuXfazqN51WsaphX9uC8uMOJzdPsRFjef1QnIjbJv6usa5cFne57w/1WeFj+YG2/dEm fiZsYE79OI1QraVMFla8BNx98JNUbyny0gjtxD1UBLKOXaADFgF64qiwJhpmKsCnW13l Zvp7CtVGE1LPjR2dHhE8/6Qxb0uSItPF+cbEapdHUd7M6U9lHDeI3bbSjv6n0kuPJew7 gGTXYdlq/iFOX46RHhEPwXw1o9Uaaa3nkECP9jk+yGhUgEFOSnQ2IRilFCv8oU8ak5Lg qtRA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=6ogzFF1vidBXb8qUr8gbdeuYvvr4G0L7hay7vGN5jrk=; b=GV8biGD3Itm7JRoXQBJRcS8D3Y6V8ujeKXGGTnoty2m0T1aBlD4ZTy3t+ncREEV4to wg3dY1wPZ/Ai8NfyjnV9RIM6StR4s1qBdkLFU/ISA+6tzGt8M72G+qOTCxJCJKyz3Yh7 OBSGdWFwzs8Sv1/l5Db/YaviI9pNoUaEJZdDH3BCXOC4dAjabqQqY60Ul7Hz/Q3jHxB2 cyfpJBRvxQP2sDFIUZhlNeCsqnohl//5HTEJsUJ9a6Iuy0gNW6UjzXeohrv4u+YR0ehN OopMdoI/k3knBAq9DqsbJYiWQqjc8ALfpu1lM0gPnb/LQu5fJt/prENC243QZm+0LZzr y0FA== X-Gm-Message-State: AOAM532/a+u4FlEV/S45fTDwIRHua5qvvy8a5daEa6v2XKJEJ8v1iSYT 9e5QPwvN2+5KLSa1IRl3d1HkDDta2oI= X-Google-Smtp-Source: ABdhPJwjFtfMyK+sAOiJ7QyESeOYFPoQId61DP7WcjKDuglqZugmp3vyRhWpSHMX6Dxt9u3oD+yP3g== X-Received: by 2002:a05:6402:1a26:b0:425:d3cf:d7f0 with SMTP id be6-20020a0564021a2600b00425d3cfd7f0mr13265179edb.251.1650909483031; Mon, 25 Apr 2022 10:58:03 -0700 (PDT) Received: from localhost.localdomain (host-79-50-86-254.retail.telecomitalia.it. [79.50.86.254]) by smtp.gmail.com with ESMTPSA id ia5-20020a170907a06500b006f392df973bsm1497207ejc.107.2022.04.25.10.58.00 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 25 Apr 2022 10:58:01 -0700 (PDT) From: "Fabio M. De Francesco" To: Greg Kroah-Hartman , =?UTF-8?q?Arve=20Hj=C3=B8nnev=C3=A5g?= , Todd Kjos , Martijn Coenen , Joel Fernandes , Christian Brauner , Hridya Valsaraju , Suren Baghdasaryan , Ira Weiny , linux-kernel@vger.kernel.org, Christophe JAILLET Cc: "Fabio M. De Francesco" , Todd Kjos Subject: [PATCH v2 2/3] binder: Use kmap_local_page() in binder_alloc_copy_user_to_buffer() Date: Mon, 25 Apr 2022 19:57:53 +0200 Message-Id: <20220425175754.8180-3-fmdefrancesco@gmail.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220425175754.8180-1-fmdefrancesco@gmail.com> References: <20220425175754.8180-1-fmdefrancesco@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The use of kmap() is being deprecated in favor of kmap_local_page() where it is feasible. With kmap_local_page(), the mapping is per thread, CPU local and not globally visible. binder_alloc_copy_user_to_buffer() is a function where the use of kmap_local_page() in place of kmap() is correctly suited because the mapping is local to the thread. Therefore, use kmap_local_page() / kunmap_local(). Cc: Christophe JAILLET Acked-by: Todd Kjos Signed-off-by: Fabio M. De Francesco --- v1->v2: Add Todd Kjos's tag in the commit message (thanks!). drivers/android/binder_alloc.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/android/binder_alloc.c b/drivers/android/binder_alloc.c index 0b3f2f569053..0875c463c002 100644 --- a/drivers/android/binder_alloc.c +++ b/drivers/android/binder_alloc.c @@ -1217,9 +1217,9 @@ binder_alloc_copy_user_to_buffer(struct binder_alloc *alloc, page = binder_alloc_get_page(alloc, buffer, buffer_offset, &pgoff); size = min_t(size_t, bytes, PAGE_SIZE - pgoff); - kptr = kmap(page) + pgoff; + kptr = kmap_local_page(page) + pgoff; ret = copy_from_user(kptr, from, size); - kunmap(page); + kunmap_local(kptr); if (ret) return bytes - size + ret; bytes -= size; -- 2.34.1