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=-14.5 required=3.0 tests=BAYES_00,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=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 19CCCC433E2 for ; Mon, 14 Sep 2020 08:38:33 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (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 573CF21548 for ; Mon, 14 Sep 2020 08:38:32 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="c1nYA/OS" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 573CF21548 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+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=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:MIME-Version:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:References:In-Reply-To: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:List-Owner; bh=ZS3v+2KEEhOAo7Cu0bj9qc7SDiw+/t/IlNkwvAvCiVc=; b=c1nYA/OSYzFFuYVtjXdZkkfFnB EQ4Lvasjv/tAnJ3WWYc3er34vRCAxrSMLI+VYHdGADSWpQaG3tVS6f1nvT0kPsN+b+tsVMCU1cWXE r2ltmX1WLRNhc3Dt3C8S/liYEo+Il9cBsm65mtAHqkGFk2BUPrXR/uGZaRtcoIobSoIgaCLNOiRc0 tWCkIlmE72uZRNl/wjHBAoTyfftu7yrRYZgSI+/ZR/q3Qdi0AM03cooItBdIoEM4zlPppKrh0ITic dpe4orOfJOenF+1/p+1tdgYwhd4fyC10gwSUbdxLYDD2FEWiqJKGBxRq3trO7h8VM0XdwgFNSlZaG FuPe3KPA==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kHjzC-0004V1-OO; Mon, 14 Sep 2020 08:37:18 +0000 Received: from foss.arm.com ([217.140.110.172]) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kHjz7-0004Tb-Hx for linux-arm-kernel@lists.infradead.org; Mon, 14 Sep 2020 08:37:15 +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 2C4CE1045; Mon, 14 Sep 2020 01:37:12 -0700 (PDT) Received: from a077416.blr.arm.com (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 07B9B3F718; Mon, 14 Sep 2020 01:37:08 -0700 (PDT) From: Amit Daniel Kachhap To: linux-arm-kernel@lists.infradead.org Subject: [PATCH v8 1/6] arm64: kprobe: add checks for ARMv8.3-PAuth combined instructions Date: Mon, 14 Sep 2020 14:06:51 +0530 Message-Id: <20200914083656.21428-2-amit.kachhap@arm.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20200914083656.21428-1-amit.kachhap@arm.com> References: <20200914083656.21428-1-amit.kachhap@arm.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200914_043713_748364_4E987909 X-CRM114-Status: GOOD ( 14.01 ) 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 , Suzuki K Poulose , Catalin Marinas , Mark Brown , James Morse , Amit Daniel Kachhap , Vincenzo Frascino , Will Deacon , Dave Martin 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+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Currently the ARMv8.3-PAuth combined branch instructions (braa, retaa etc.) are not simulated for out-of-line execution with a handler. Hence the uprobe of such instructions leads to kernel warnings in a loop as they are not explicitly checked and fall into INSN_GOOD categories. Other combined instructions like LDRAA and LDRBB can be probed. The issue of the combined branch instructions is fixed by adding group definitions of all such instructions and rejecting their probes. The instruction groups added are br_auth(braa, brab, braaz and brabz), blr_auth(blraa, blrab, blraaz and blrabz), ret_auth(retaa and retab) and eret_auth(eretaa and eretab). Warning log: WARNING: CPU: 0 PID: 156 at arch/arm64/kernel/probes/uprobes.c:182 uprobe_single_step_handler+0x34/0x50 Modules linked in: CPU: 0 PID: 156 Comm: func Not tainted 5.9.0-rc3 #188 Hardware name: Foundation-v8A (DT) pstate: 804003c9 (Nzcv DAIF +PAN -UAO BTYPE=--) pc : uprobe_single_step_handler+0x34/0x50 lr : single_step_handler+0x70/0xf8 sp : ffff800012af3e30 x29: ffff800012af3e30 x28: ffff000878723b00 x27: 0000000000000000 x26: 0000000000000000 x25: 0000000000000000 x24: 0000000000000000 x23: 0000000060001000 x22: 00000000cb000022 x21: ffff800012065ce8 x20: ffff800012af3ec0 x19: ffff800012068d50 x18: 0000000000000000 x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000000000 x14: 0000000000000000 x13: 0000000000000000 x12: 0000000000000000 x11: 0000000000000000 x10: 0000000000000000 x9 : ffff800010085c90 x8 : 0000000000000000 x7 : 0000000000000000 x6 : ffff80001205a9c8 x5 : ffff80001205a000 x4 : ffff80001233db80 x3 : ffff8000100a7a60 x2 : 0020000000000003 x1 : 0000fffffffff008 x0 : ffff800012af3ec0 Call trace: uprobe_single_step_handler+0x34/0x50 single_step_handler+0x70/0xf8 do_debug_exception+0xb8/0x130 el0_sync_handler+0x138/0x1b8 el0_sync+0x158/0x180 Fixes: 74afda4016a7 ("arm64: compile the kernel with ptrauth return address signing") Fixes: 04ca3204fa09 ("arm64: enable pointer authentication") Signed-off-by: Amit Daniel Kachhap Reviewed-by: Dave Martin --- arch/arm64/include/asm/insn.h | 4 ++++ arch/arm64/kernel/insn.c | 5 ++++- arch/arm64/kernel/probes/decode-insn.c | 3 ++- 3 files changed, 10 insertions(+), 2 deletions(-) diff --git a/arch/arm64/include/asm/insn.h b/arch/arm64/include/asm/insn.h index 0bc46149e491..4b39293d0f72 100644 --- a/arch/arm64/include/asm/insn.h +++ b/arch/arm64/include/asm/insn.h @@ -359,9 +359,13 @@ __AARCH64_INSN_FUNCS(brk, 0xFFE0001F, 0xD4200000) __AARCH64_INSN_FUNCS(exception, 0xFF000000, 0xD4000000) __AARCH64_INSN_FUNCS(hint, 0xFFFFF01F, 0xD503201F) __AARCH64_INSN_FUNCS(br, 0xFFFFFC1F, 0xD61F0000) +__AARCH64_INSN_FUNCS(br_auth, 0xFEFFF800, 0xD61F0800) __AARCH64_INSN_FUNCS(blr, 0xFFFFFC1F, 0xD63F0000) +__AARCH64_INSN_FUNCS(blr_auth, 0xFEFFF800, 0xD63F0800) __AARCH64_INSN_FUNCS(ret, 0xFFFFFC1F, 0xD65F0000) +__AARCH64_INSN_FUNCS(ret_auth, 0xFFFFFBFF, 0xD65F0BFF) __AARCH64_INSN_FUNCS(eret, 0xFFFFFFFF, 0xD69F03E0) +__AARCH64_INSN_FUNCS(eret_auth, 0xFFFFFBFF, 0xD69F0BFF) __AARCH64_INSN_FUNCS(mrs, 0xFFF00000, 0xD5300000) __AARCH64_INSN_FUNCS(msr_imm, 0xFFF8F01F, 0xD500401F) __AARCH64_INSN_FUNCS(msr_reg, 0xFFF00000, 0xD5100000) diff --git a/arch/arm64/kernel/insn.c b/arch/arm64/kernel/insn.c index a107375005bc..ccc8c9e22b25 100644 --- a/arch/arm64/kernel/insn.c +++ b/arch/arm64/kernel/insn.c @@ -176,7 +176,7 @@ bool __kprobes aarch64_insn_uses_literal(u32 insn) bool __kprobes aarch64_insn_is_branch(u32 insn) { - /* b, bl, cb*, tb*, b.cond, br, blr */ + /* b, bl, cb*, tb*, ret*, b.cond, br*, blr* */ return aarch64_insn_is_b(insn) || aarch64_insn_is_bl(insn) || @@ -185,8 +185,11 @@ bool __kprobes aarch64_insn_is_branch(u32 insn) aarch64_insn_is_tbz(insn) || aarch64_insn_is_tbnz(insn) || aarch64_insn_is_ret(insn) || + aarch64_insn_is_ret_auth(insn) || aarch64_insn_is_br(insn) || + aarch64_insn_is_br_auth(insn) || aarch64_insn_is_blr(insn) || + aarch64_insn_is_blr_auth(insn) || aarch64_insn_is_bcond(insn); } diff --git a/arch/arm64/kernel/probes/decode-insn.c b/arch/arm64/kernel/probes/decode-insn.c index 263d5fba4c8a..c541fb48886e 100644 --- a/arch/arm64/kernel/probes/decode-insn.c +++ b/arch/arm64/kernel/probes/decode-insn.c @@ -29,7 +29,8 @@ static bool __kprobes aarch64_insn_is_steppable(u32 insn) aarch64_insn_is_msr_imm(insn) || aarch64_insn_is_msr_reg(insn) || aarch64_insn_is_exception(insn) || - aarch64_insn_is_eret(insn)) + aarch64_insn_is_eret(insn) || + aarch64_insn_is_eret_auth(insn)) return false; /* -- 2.17.1 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel