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[2620:137:e000::1:20]) by mx.google.com with ESMTP id e26-20020a65679a000000b005576714126csi729966pgr.671.2023.06.23.20.50.49; Fri, 23 Jun 2023 20:51:02 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229786AbjFXD0f (ORCPT + 99 others); Fri, 23 Jun 2023 23:26:35 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45176 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229451AbjFXD0d (ORCPT ); Fri, 23 Jun 2023 23:26:33 -0400 Received: from bg4.exmail.qq.com (bg4.exmail.qq.com [43.154.54.12]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DFC371B9 for ; Fri, 23 Jun 2023 20:26:30 -0700 (PDT) X-QQ-mid: bizesmtp73t1687577181tb6gbdfh Received: from localhost.localdomain ( [58.240.82.166]) by bizesmtp.qq.com (ESMTP) with id ; Sat, 24 Jun 2023 11:26:20 +0800 (CST) X-QQ-SSF: 01200000000000B0B000000A0000000 X-QQ-FEAT: ZdHcY4j9T+LMhqKHibX+gEym75LAizUeDwYPbOc+hBMYZZB/hIeGJqbOmbemd GsBRNduMYrhwB+Xycx9/oc+AAULh/ZqzZFZiHvkWNiRlIbIz9vJo5vlY0JUL6pb9mqEiAD5 kCkzc7DWNUOMMZzRoPnkMR9fzdjkXRTUWyMc3o6vsVYx1Ti99jvbu5x0q2Szc1TiQ51TnfJ HfJPWZlVwFAQRgdDxDxvtIExDf2AWqdBgfWQ+dO20QXI//G9Cek12DyLYSAMYLKbFvBh6+7 F93bCs6F4+YtB0sUj8DH0gr3LX119iyO7F5ZNfWr5ZwwYk0DmYzRIK0xitJAe3JVGMrvIiW rFGqVFNNqufSVbVbgU= X-QQ-GoodBg: 0 X-BIZMAIL-ID: 14577591654747292187 From: Song Shuai To: rppt@kernel.org, akpm@linux-foundation.org Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Song Shuai Subject: [PATCH] memblock: report failures when memblock_can_resize is not set Date: Sat, 24 Jun 2023 11:26:07 +0800 Message-Id: <20230624032607.921173-1-songshuaishuai@tinylab.org> X-Mailer: git-send-email 2.20.1 MIME-Version: 1.0 X-QQ-SENDSIZE: 520 Feedback-ID: bizesmtp:tinylab.org:qybglogicsvrgz:qybglogicsvrgz5a-3 X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00,SPF_HELO_NONE, SPF_PASS,T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-getmail-retrieved-from-mailbox: =?utf-8?q?INBOX?= X-GMAIL-THRID: =?utf-8?q?1769554483738503506?= X-GMAIL-MSGID: =?utf-8?q?1769554483738503506?= The callers of memblock_reserve() do not check the return value presuming that memblock_reserve() always succeeds, but there are cases where it may fail. Having numerous memblock reservations at early boot where memblock_can_resize is unset may exhaust the INIT_MEMBLOCK_REGIONS sized memblock.reserved regions array and an attempt to double this array via memblock_double_array() will fail and will return -1 to the caller. When this happens the system crashes anyway, but it's hard to identify the reason for the crash. Add a panic message to memblock_double_array() to aid debugging of the cases when too many regions are reserved before memblock can resize memblock.reserved array. Link: https://lore.kernel.org/linux-kernel/20230614131746.3670303-1-songshuaishuai@tinylab.org/ Signed-off-by: Song Shuai --- mm/memblock.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/memblock.c b/mm/memblock.c index 3feafea06ab2..1b8e902490e5 100644 --- a/mm/memblock.c +++ b/mm/memblock.c @@ -419,7 +419,7 @@ static int __init_memblock memblock_double_array(struct memblock_type *type, * of memory that aren't suitable for allocation */ if (!memblock_can_resize) - return -1; + panic("memblock: cannot resize %s array\n", type->name); /* Calculate new doubled size */ old_size = type->max * sizeof(struct memblock_region);