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=-2.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,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 668B7ECDFBB for ; Fri, 20 Jul 2018 12:36:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2CC5F206B7 for ; Fri, 20 Jul 2018 12:36:49 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2CC5F206B7 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linuxfoundation.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389138AbeGTNYt (ORCPT ); Fri, 20 Jul 2018 09:24:49 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:44578 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387847AbeGTNYr (ORCPT ); Fri, 20 Jul 2018 09:24:47 -0400 Received: from localhost (LFbn-1-12238-233.w90-92.abo.wanadoo.fr [90.92.53.233]) by mail.linuxfoundation.org (Postfix) with ESMTPSA id DE706CAE; Fri, 20 Jul 2018 12:34:49 +0000 (UTC) From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Greg Kroah-Hartman , Mark Rutland , Julien Grall , Will Deacon , Marc Zyngier , Catalin Marinas Subject: [PATCH 4.14 79/92] arm64: Call ARCH_WORKAROUND_2 on transitions between EL0 and EL1 Date: Fri, 20 Jul 2018 14:14:23 +0200 Message-Id: <20180720121422.266514737@linuxfoundation.org> X-Mailer: git-send-email 2.18.0 In-Reply-To: <20180720121417.206337808@linuxfoundation.org> References: <20180720121417.206337808@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Marc Zyngier commit 8e2906245f1e3b0d027169d9f2e55ce0548cb96e upstream. In order for the kernel to protect itself, let's call the SSBD mitigation implemented by the higher exception level (either hypervisor or firmware) on each transition between userspace and kernel. We must take the PSCI conduit into account in order to target the right exception level, hence the introduction of a runtime patching callback. Reviewed-by: Mark Rutland Reviewed-by: Julien Grall Acked-by: Will Deacon Signed-off-by: Marc Zyngier Signed-off-by: Catalin Marinas Signed-off-by: Marc Zyngier Signed-off-by: Greg Kroah-Hartman --- arch/arm64/kernel/cpu_errata.c | 24 ++++++++++++++++++++++++ arch/arm64/kernel/entry.S | 22 ++++++++++++++++++++++ include/linux/arm-smccc.h | 5 +++++ 3 files changed, 51 insertions(+) --- a/arch/arm64/kernel/cpu_errata.c +++ b/arch/arm64/kernel/cpu_errata.c @@ -228,6 +228,30 @@ static int qcom_enable_link_stack_saniti } #endif /* CONFIG_HARDEN_BRANCH_PREDICTOR */ +#ifdef CONFIG_ARM64_SSBD +void __init arm64_update_smccc_conduit(struct alt_instr *alt, + __le32 *origptr, __le32 *updptr, + int nr_inst) +{ + u32 insn; + + BUG_ON(nr_inst != 1); + + switch (psci_ops.conduit) { + case PSCI_CONDUIT_HVC: + insn = aarch64_insn_get_hvc_value(); + break; + case PSCI_CONDUIT_SMC: + insn = aarch64_insn_get_smc_value(); + break; + default: + return; + } + + *updptr = cpu_to_le32(insn); +} +#endif /* CONFIG_ARM64_SSBD */ + #define MIDR_RANGE(model, min, max) \ .def_scope = SCOPE_LOCAL_CPU, \ .matches = is_affected_midr_range, \ --- a/arch/arm64/kernel/entry.S +++ b/arch/arm64/kernel/entry.S @@ -18,6 +18,7 @@ * along with this program. If not, see . */ +#include #include #include @@ -137,6 +138,18 @@ alternative_else_nop_endif add \dst, \dst, #(\sym - .entry.tramp.text) .endm + // This macro corrupts x0-x3. It is the caller's duty + // to save/restore them if required. + .macro apply_ssbd, state +#ifdef CONFIG_ARM64_SSBD + mov w0, #ARM_SMCCC_ARCH_WORKAROUND_2 + mov w1, #\state +alternative_cb arm64_update_smccc_conduit + nop // Patched to SMC/HVC #0 +alternative_cb_end +#endif + .endm + .macro kernel_entry, el, regsize = 64 .if \regsize == 32 mov w0, w0 // zero upper 32 bits of x0 @@ -163,6 +176,13 @@ alternative_else_nop_endif ldr x19, [tsk, #TSK_TI_FLAGS] // since we can unmask debug disable_step_tsk x19, x20 // exceptions when scheduling. + apply_ssbd 1 + +#ifdef CONFIG_ARM64_SSBD + ldp x0, x1, [sp, #16 * 0] + ldp x2, x3, [sp, #16 * 1] +#endif + mov x29, xzr // fp pointed to user-space .else add x21, sp, #S_FRAME_SIZE @@ -301,6 +321,8 @@ alternative_if ARM64_WORKAROUND_845719 alternative_else_nop_endif #endif 3: + apply_ssbd 0 + .endif msr elr_el1, x21 // set up the return data --- a/include/linux/arm-smccc.h +++ b/include/linux/arm-smccc.h @@ -80,6 +80,11 @@ ARM_SMCCC_SMC_32, \ 0, 0x8000) +#define ARM_SMCCC_ARCH_WORKAROUND_2 \ + ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL, \ + ARM_SMCCC_SMC_32, \ + 0, 0x7fff) + #ifndef __ASSEMBLY__ #include