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=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,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 6B23EC5519A for ; Mon, 27 Apr 2020 06:25:52 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 3E2BE206B6 for ; Mon, 27 Apr 2020 06:25:52 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="W4MsmCv+" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3E2BE206B6 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:MIME-Version:Cc:List-Subscribe: List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id:Message-Id:Date: Subject:To:From:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To: References:List-Owner; bh=XjNfkSWWoScprGG90YdrAeGpy1lmSP8/xysVfffoHAg=; b=W4M smCv+vlF9px9hcs219UsvDjvg901FI1EOymES/Jv5kcsUtk56dD88eELyiSkjjbzMYf/OWxXnAUFJ Edj5uSx3sKhfSyyDFAhFo6PhnqYwpcsxrOdgCe2fxBzp5mfaa7/M5kqOWnmJzotc0Q1euLWiflzaQ A4rLNCYEyj+Iig0BK4n8A7AGE0dLo2fbKyVAU3GGS3OVCTVtwFbjRPjMVamq7X0os/MKjIAw6dXX5 ZlPrfWrn5Neh1hlkWsnbHranjKKHZWeae3HZ8LXGvciE3gew0wEOGEKqfqEdKoSQgJ7Il1rx99oFa gCcnWQVxrVmWOnQCZ3S8Crz9UQrzUEA==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1jSxDB-0003Mm-RM; Mon, 27 Apr 2020 06:25:49 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1jSxCi-0002t3-5O; Mon, 27 Apr 2020 06:25:23 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 6999931B; Sun, 26 Apr 2020 23:25:15 -0700 (PDT) Received: from a075553-lin.blr.arm.com (a075553-lin.blr.arm.com [10.162.17.24]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id A1AF13F73D; Sun, 26 Apr 2020 23:25:12 -0700 (PDT) From: Amit Daniel Kachhap To: linux-arm-kernel@lists.infradead.org Subject: [PATCH v2 1/2] arm64/crash_core: Export KERNELPACMASK in vmcoreinfo Date: Mon, 27 Apr 2020 11:55:01 +0530 Message-Id: <1587968702-19996-1-git-send-email-amit.kachhap@arm.com> X-Mailer: git-send-email 2.7.4 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200426_232521_743639_494B663B X-CRM114-Status: GOOD ( 10.70 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , Catalin Marinas , Bhupesh Sharma , kexec@lists.infradead.org, linux-kernel@vger.kernel.org, James Morse , Amit Daniel Kachhap , Vincenzo Frascino , Will Deacon MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org Recently arm64 linux kernel added support for Armv8.3-A Pointer Authentication feature. If this feature is enabled in the kernel and the hardware supports address authentication then the return addresses are signed and stored in the stack to prevent ROP kind of attack. Kdump tool will now dump the kernel with signed lr values in the stack. Any user analysis tool for this kernel dump may need the kernel pac mask information in vmcoreinfo to generate the correct return address for stacktrace purpose as well as to resolve the symbol name. This patch is similar to commit ec6e822d1a22d0eef ("arm64: expose user PAC bit positions via ptrace") which exposes pac mask information via ptrace interfaces. Cc: Catalin Marinas Cc: Will Deacon Cc: Mark Rutland Signed-off-by: Amit Daniel Kachhap --- Changes since v1: * Rebased to kernel 5.7-rc3. * commit log change. An implementation of this new KERNELPACMASK vmcoreinfo field used by crash tool can be found here[1]. This change is accepted by crash utility maintainer [2]. [1]: https://www.redhat.com/archives/crash-utility/2020-April/msg00095.html [2]: https://www.redhat.com/archives/crash-utility/2020-April/msg00099.html arch/arm64/include/asm/compiler.h | 3 +++ arch/arm64/kernel/crash_core.c | 4 ++++ 2 files changed, 7 insertions(+) diff --git a/arch/arm64/include/asm/compiler.h b/arch/arm64/include/asm/compiler.h index eece20d..32d5900 100644 --- a/arch/arm64/include/asm/compiler.h +++ b/arch/arm64/include/asm/compiler.h @@ -19,6 +19,9 @@ #define __builtin_return_address(val) \ (void *)(ptrauth_clear_pac((unsigned long)__builtin_return_address(val))) +#else /* !CONFIG_ARM64_PTR_AUTH */ +#define ptrauth_user_pac_mask() 0ULL +#define ptrauth_kernel_pac_mask() 0ULL #endif /* CONFIG_ARM64_PTR_AUTH */ #endif /* __ASM_COMPILER_H */ diff --git a/arch/arm64/kernel/crash_core.c b/arch/arm64/kernel/crash_core.c index ca4c3e1..25cf2ce 100644 --- a/arch/arm64/kernel/crash_core.c +++ b/arch/arm64/kernel/crash_core.c @@ -6,6 +6,7 @@ #include #include +#include void arch_crash_save_vmcoreinfo(void) { @@ -16,4 +17,7 @@ void arch_crash_save_vmcoreinfo(void) vmcoreinfo_append_str("NUMBER(PHYS_OFFSET)=0x%llx\n", PHYS_OFFSET); vmcoreinfo_append_str("KERNELOFFSET=%lx\n", kaslr_offset()); + vmcoreinfo_append_str("NUMBER(KERNELPACMASK)=0x%llx\n", + system_supports_address_auth() ? + ptrauth_kernel_pac_mask() : 0); } -- 2.7.4 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel