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=-26.3 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=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 DBBDEC43381 for ; Fri, 15 Jan 2021 11:46:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B9CBB2389B for ; Fri, 15 Jan 2021 11:46:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728941AbhAOLqe (ORCPT ); Fri, 15 Jan 2021 06:46:34 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57064 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728444AbhAOLqd (ORCPT ); Fri, 15 Jan 2021 06:46:33 -0500 Received: from mail-qk1-x74a.google.com (mail-qk1-x74a.google.com [IPv6:2607:f8b0:4864:20::74a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3784DC061794 for ; Fri, 15 Jan 2021 03:45:53 -0800 (PST) Received: by mail-qk1-x74a.google.com with SMTP id b206so7646669qkc.14 for ; Fri, 15 Jan 2021 03:45:53 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=sender:date:in-reply-to:message-id:mime-version:references:subject :from:to:cc; bh=jR//nrlijl/JEPmJhF1uzhnuEqPPRoekagqUwRo/Wps=; b=NGPjIfYxeqdggFn0u42r+MwCt7fcCb+wOyNjTm0ctsFkxreS2Ffu8SRGHqhs0XWLbL +HC2gFKPh7WaOkbsWr3THWOSM5ljVoBQVV8EsAvbVp4Eoi3at0yKmhVlZvlp0WghefDt 3U+TYnTCRMNuCmPtJQ49lVNiN9ysRsCwIIx90PEiE8pTamnzhRy+3YNidyS4JikS95t4 wD6QHUqG28ZLTp260KgzM572Cj5IFyFQuF5y8Ek0oIoE9SzALmpLFN+Zp7aZaNg1Z3xN D1WY81Es/YODjFsLFoiV6C4sPToyQAyzwbIj5yFUW+LElCnpfsO+dLCGPH6pL6DXf9Rf stUQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=jR//nrlijl/JEPmJhF1uzhnuEqPPRoekagqUwRo/Wps=; b=BEbIKrGZhecePFZiju2cvJC2D0zh9Ferzr17gXI6nDgReHCTFh5NxmB2qau+vZY3m+ QPDHCstLMEa8/x361UuPPZYMLKzBPlq1kfBp/sLaLwk6xLICkomoXcZLlALCUyBaTzTT oKRU98ERkMSxNv1RsrcYWkV487ODYxhD5Fl6eDD3mvgGKM8VhG7dlzV797M6NYZaR5/x JkaATWOZkDznpvkitbuhcqLaOqRhjoj+coqfR+/aF7Ih1c08/yEIWOaadc9hfvrJ5hLr EB7yLZGh5JnqwkpJBW+s13COPPBTlHFWueiP9rRvPoruguzCGI90TTf6vRHYKnPym6Hz GUNQ== X-Gm-Message-State: AOAM531XgbcdeXW04T8zgbShE2aUcKgVWQ1qvWJSuDK72cjwbFmvvuf7 VXkp0H0jyZv0sVBYyDb9Fwjku6bOIf6j X-Google-Smtp-Source: ABdhPJzig+EXRL+D7XvYHYAIQivncwYh6hTL6zFdhd5ydmxvjATXyRAcl027gxFVsO0+c9Ta3VivoGMe9AQK Sender: "qperret via sendgmr" X-Received: from r2d2-qp.c.googlers.com ([fda3:e722:ac3:cc00:28:9cb1:c0a8:1652]) (user=qperret job=sendgmr) by 2002:a05:6214:b12:: with SMTP id u18mr5640495qvj.21.1610711152432; Fri, 15 Jan 2021 03:45:52 -0800 (PST) Date: Fri, 15 Jan 2021 11:45:44 +0000 In-Reply-To: <20210115114544.1830068-1-qperret@google.com> Message-Id: <20210115114544.1830068-3-qperret@google.com> Mime-Version: 1.0 References: <20210115114544.1830068-1-qperret@google.com> X-Mailer: git-send-email 2.30.0.284.gd98b1dd5eaa7-goog Subject: [PATCH 2/2] of/fdt: Make sure no-map does not remove already reserved regions From: Quentin Perret To: robh+dt@kernel.org, frowand.list@gmail.com Cc: devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, drinkcat@chromium.org, swboyd@chromium.org, f.fainelli@gmail.com, karahmed@amazon.de, kernel-team@android.com Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Nicolas Boichat If the device tree is incorrectly configured, and attempts to define a "no-map" reserved memory that overlaps with the kernel data/code, the kernel would crash quickly after boot, with no obvious clue about the nature of the issue. For example, this would happen if we have the kernel mapped at these addresses (from /proc/iomem): 40000000-41ffffff : System RAM 40080000-40dfffff : Kernel code 40e00000-411fffff : reserved 41200000-413e0fff : Kernel data And we declare a no-map shared-dma-pool region at a fixed address within that range: mem_reserved: mem_region { compatible = "shared-dma-pool"; reg = <0 0x40000000 0 0x01A00000>; no-map; }; To fix this, when removing memory regions at early boot (which is what "no-map" regions do), we need to make sure that the memory is not already reserved. If we do, __reserved_mem_reserve_reg will throw an error: [ 0.000000] OF: fdt: Reserved memory: failed to reserve memory for node 'mem_region': base 0x0000000040000000, size 26 MiB and the code that will try to use the region should also fail, later on. We do not do anything for non-"no-map" regions, as memblock explicitly allows reserved regions to overlap, and the commit that this fixes removed the check for that precise reason. [ qperret: fixed conflicts caused by the usage of memblock_mark_nomap ] Fixes: 094cb98179f19b7 ("of/fdt: memblock_reserve /memreserve/ regions in the case of partial overlap") Signed-off-by: Nicolas Boichat Reviewed-by: Stephen Boyd Signed-off-by: Quentin Perret --- drivers/of/fdt.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c index 427b534d60d2..dcc1dd96911a 100644 --- a/drivers/of/fdt.c +++ b/drivers/of/fdt.c @@ -1146,8 +1146,16 @@ int __init __weak early_init_dt_mark_hotplug_memory_arch(u64 base, u64 size) int __init __weak early_init_dt_reserve_memory_arch(phys_addr_t base, phys_addr_t size, bool nomap) { - if (nomap) + if (nomap) { + /* + * If the memory is already reserved (by another region), we + * should not allow it to be marked nomap. + */ + if (memblock_is_region_reserved(base, size)) + return -EBUSY; + return memblock_mark_nomap(base, size); + } return memblock_reserve(base, size); } -- 2.30.0.284.gd98b1dd5eaa7-goog