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=-26.2 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT,USER_IN_DEF_DKIM_WL autolearn=unavailable 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 BCA8BC433DB for ; Wed, 3 Feb 2021 00:32:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 80D9264F6A for ; Wed, 3 Feb 2021 00:32:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232396AbhBCAcT (ORCPT ); Tue, 2 Feb 2021 19:32:19 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44752 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232295AbhBCAcR (ORCPT ); Tue, 2 Feb 2021 19:32:17 -0500 Received: from mail-yb1-xb49.google.com (mail-yb1-xb49.google.com [IPv6:2607:f8b0:4864:20::b49]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0A2CFC0613D6 for ; Tue, 2 Feb 2021 16:31:37 -0800 (PST) Received: by mail-yb1-xb49.google.com with SMTP id s7so25684363ybj.0 for ; Tue, 02 Feb 2021 16:31:36 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=sender:date:message-id:mime-version:subject:from:to:cc; bh=SOXagrKaf/SGUJ0It1u1ORMjiyQ7gfGWlZufV5zUWJE=; b=Du2OOc57uVZ5uhkj2egHtA2wa0SFb9m9+y9NUmdFQiDq6WF2NakwTwFWFMXWVb3EBL 6yZFOR+lPWlQVyiwF9d8puYRUFCxEGC1+R29nJZU8FOnSiKOy4numK8O9O1pWyf7m1VF 8chND7Te/w1IUSVTEvSM8juDTdD/Y9h/tjYjVRIOVVMIrQ95XmURDbfFMzRgUhQ3iaW/ ykaovl20AETBww7DpJLvE4T3DJlaYWWtMgd5XgGU2SXCdiQbXAqgAOVTrRqQT/IObwbO wz8tYr1IEZgh7+XbFH1Jf8hI3AA5tNm6TDQlfW/GVzGjDcRPqQagtp6MdCrThoU9FjSr Qs3Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:date:message-id:mime-version:subject:from :to:cc; bh=SOXagrKaf/SGUJ0It1u1ORMjiyQ7gfGWlZufV5zUWJE=; b=sk/hQgjiH+ueFvsG/6eO3/jApbDJV8rEeIMfJjVbTPjFh75nVaca6ZC7X8d2ecTaWZ VONvZsqpwoVZvdf3H5VWo+CiYNrdLkdRt+uECc3zPQg4jWIVGYSC7Y/OlrJbg76g7AA9 nlb6dIpekuZop6lXpfWBlxjADds/x3Uan/JKhnFVOFqPhvdMkBiJZ46wW/1LYuQR36j3 bUm7LiTAlSL+biXoPwKjMdnFTXvdrc8/c78DtqNvGcLZ9IBxAZvS3e4ygZKcaFDPL9+X U7CkXvvp9KIg2oCd7tCI0FkK/b+7m3DTHlJkzTNWS95TLKgPGk6l5QUCHirX/dR1RuXT FwLQ== X-Gm-Message-State: AOAM5313ufc/psHTeU+SrKWd/peWaFSjY+Z+O2F23gpZR74rVd7d17JB LU3LBnHzXmd95xVCKqorbGozGhcBXqw= X-Google-Smtp-Source: ABdhPJx1oe0/DgxGORm9UrMRCk0QL4fxRFPA1BcJxhU6LPzwDc8fSpOWryrH8a7W+r9pJcxrhxvwKlDBtU0= Sender: "surenb via sendgmr" X-Received: from surenb1.mtv.corp.google.com ([2620:15c:211:200:9194:cd6:1ec:3e2d]) (user=surenb job=sendgmr) by 2002:a05:6902:1025:: with SMTP id x5mr707532ybt.21.1612312296088; Tue, 02 Feb 2021 16:31:36 -0800 (PST) Date: Tue, 2 Feb 2021 16:31:33 -0800 Message-Id: <20210203003134.2422308-1-surenb@google.com> Mime-Version: 1.0 X-Mailer: git-send-email 2.30.0.365.g02bc693789-goog Subject: [PATCH 1/2] mm: replace BUG_ON in vm_insert_page with a return of an error From: Suren Baghdasaryan To: sumit.semwal@linaro.org Cc: akpm@linux-foundation.org, hch@infradead.org, lmark@codeaurora.org, labbott@redhat.com, Brian.Starkey@arm.com, john.stultz@linaro.org, christian.koenig@amd.com, cgoldswo@codeaurora.org, orjan.eide@arm.com, robin.murphy@arm.com, jajones@nvidia.com, minchan@kernel.org, hridya@google.com, sspatil@google.com, linux-media@vger.kernel.org, dri-devel@lists.freedesktop.org, linaro-mm-sig@lists.linaro.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, kernel-team@android.com, surenb@google.com Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Replace BUG_ON(vma->vm_flags & VM_PFNMAP) in vm_insert_page with WARN_ON_ONCE and returning an error. This is to ensure users of the vm_insert_page that set VM_PFNMAP are notified of the wrong flag usage and get an indication of an error without panicing the kernel. This will help identifying drivers that need to clear VM_PFNMAP before using dmabuf system heap which is moving to use vm_insert_page. Suggested-by: Christoph Hellwig Signed-off-by: Suren Baghdasaryan --- mm/memory.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/mm/memory.c b/mm/memory.c index feff48e1465a..e503c9801cd9 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -1827,7 +1827,8 @@ int vm_insert_page(struct vm_area_struct *vma, unsigned long addr, return -EINVAL; if (!(vma->vm_flags & VM_MIXEDMAP)) { BUG_ON(mmap_read_trylock(vma->vm_mm)); - BUG_ON(vma->vm_flags & VM_PFNMAP); + if (WARN_ON_ONCE(vma->vm_flags & VM_PFNMAP)) + return -EINVAL; vma->vm_flags |= VM_MIXEDMAP; } return insert_page(vma, addr, page, vma->vm_page_prot); -- 2.30.0.365.g02bc693789-goog