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=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT 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 862D0C31E40 for ; Fri, 9 Aug 2019 10:09:01 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 058102171F for ; Fri, 9 Aug 2019 10:09:01 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 058102171F Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=huawei.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from bilbo.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 464gtz0q8DzDqsr for ; Fri, 9 Aug 2019 20:08:59 +1000 (AEST) Authentication-Results: lists.ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=huawei.com (client-ip=45.249.212.191; helo=huawei.com; envelope-from=yanaijie@huawei.com; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=huawei.com Received: from huawei.com (szxga05-in.huawei.com [45.249.212.191]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 464gWW4VwvzDqmh for ; Fri, 9 Aug 2019 19:52:07 +1000 (AEST) Received: from DGGEMS403-HUB.china.huawei.com (unknown [172.30.72.58]) by Forcepoint Email with ESMTP id 0FD4448BB7BFEF59E24E; Fri, 9 Aug 2019 17:52:03 +0800 (CST) Received: from huawei.com (10.175.124.28) by DGGEMS403-HUB.china.huawei.com (10.3.19.203) with Microsoft SMTP Server id 14.3.439.0; Fri, 9 Aug 2019 17:51:57 +0800 From: Jason Yan To: , , , , , , , , Subject: [PATCH v6 10/12] powerpc/fsl_booke/kaslr: dump out kernel offset information on panic Date: Fri, 9 Aug 2019 18:07:58 +0800 Message-ID: <20190809100800.5426-11-yanaijie@huawei.com> X-Mailer: git-send-email 2.17.2 In-Reply-To: <20190809100800.5426-1-yanaijie@huawei.com> References: <20190809100800.5426-1-yanaijie@huawei.com> MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.175.124.28] X-CFilter-Loop: Reflected X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: wangkefeng.wang@huawei.com, Jason Yan , linux-kernel@vger.kernel.org, jingxiangfeng@huawei.com, zhaohongjiang@huawei.com, thunder.leizhen@huawei.com, fanchengyang@huawei.com, yebin10@huawei.com Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" When kaslr is enabled, the kernel offset is different for every boot. This brings some difficult to debug the kernel. Dump out the kernel offset when panic so that we can easily debug the kernel. This code is derived from x86/arm64 which has similar functionality. Signed-off-by: Jason Yan Cc: Diana Craciun Cc: Michael Ellerman Cc: Christophe Leroy Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Nicholas Piggin Cc: Kees Cook Reviewed-by: Christophe Leroy Reviewed-by: Diana Craciun Tested-by: Diana Craciun --- arch/powerpc/include/asm/page.h | 5 +++++ arch/powerpc/kernel/setup-common.c | 20 ++++++++++++++++++++ 2 files changed, 25 insertions(+) diff --git a/arch/powerpc/include/asm/page.h b/arch/powerpc/include/asm/page.h index 4d32d1b561d6..b34b9cdd91f1 100644 --- a/arch/powerpc/include/asm/page.h +++ b/arch/powerpc/include/asm/page.h @@ -317,6 +317,11 @@ struct vm_area_struct; extern unsigned long kernstart_virt_addr; +static inline unsigned long kaslr_offset(void) +{ + return kernstart_virt_addr - KERNELBASE; +} + #include #endif /* __ASSEMBLY__ */ #include diff --git a/arch/powerpc/kernel/setup-common.c b/arch/powerpc/kernel/setup-common.c index 1f8db666468d..ba1a34ab218a 100644 --- a/arch/powerpc/kernel/setup-common.c +++ b/arch/powerpc/kernel/setup-common.c @@ -715,8 +715,28 @@ static struct notifier_block ppc_panic_block = { .priority = INT_MIN /* may not return; must be done last */ }; +/* + * Dump out kernel offset information on panic. + */ +static int dump_kernel_offset(struct notifier_block *self, unsigned long v, + void *p) +{ + pr_emerg("Kernel Offset: 0x%lx from 0x%lx\n", + kaslr_offset(), KERNELBASE); + + return 0; +} + +static struct notifier_block kernel_offset_notifier = { + .notifier_call = dump_kernel_offset +}; + void __init setup_panic(void) { + if (IS_ENABLED(CONFIG_RANDOMIZE_BASE) && kaslr_offset() > 0) + atomic_notifier_chain_register(&panic_notifier_list, + &kernel_offset_notifier); + /* PPC64 always does a hard irq disable in its panic handler */ if (!IS_ENABLED(CONFIG_PPC64) && !ppc_md.panic) return; -- 2.17.2