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=-6.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 8C26FC43381 for ; Mon, 1 Apr 2019 17:54:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5DCF82084B for ; Mon, 1 Apr 2019 17:54:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1554141269; bh=AuIKCoDQMko9Dawfi++v5HGdLmxb8riKOG7DS7sM5Ts=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=DFDUQTk6AiZxlsFKZV+y9c08t3wWUByi8FPK01w15qyyNhkKPNSuZsdxZoeRPUqb8 t+oE+XwVeEls9dkj7SnyqucsId0kt0iJI8x39jExKOX2wZCduTAalouNNg7tnlfF/U nTj+6eAoKAUK1YksmgTtahIMj299u3E2Eyk0Ul+s= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729784AbfDARYe (ORCPT ); Mon, 1 Apr 2019 13:24:34 -0400 Received: from mail.kernel.org ([198.145.29.99]:55092 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732073AbfDARYa (ORCPT ); Mon, 1 Apr 2019 13:24:30 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 6944820880; Mon, 1 Apr 2019 17:24:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1554139469; bh=AuIKCoDQMko9Dawfi++v5HGdLmxb8riKOG7DS7sM5Ts=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=wEXz7EBxSrio1Nr4xnMyBG/ngsLR0R6i5fhrVPBymy8sTTZcKZ2XU6heRGqVisf4u 5Qf3FMRhP9wPDbROpd/G/qZDJZ+FAH472CFPF3rDvtuUjmDYArWJQIGTRGElliMiUh PHg0gn0WZ1x+x+1mOIKJMui3XW9NVZIQAAo0YFII= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Diana Craciun , Michael Ellerman Subject: [PATCH 4.14 048/107] powerpc/fsl: Flush the branch predictor at each kernel entry (64bit) Date: Mon, 1 Apr 2019 19:02:03 +0200 Message-Id: <20190401170050.191600220@linuxfoundation.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190401170045.246405031@linuxfoundation.org> References: <20190401170045.246405031@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Diana Craciun commit 10c5e83afd4a3f01712d97d3bb1ae34d5b74a185 upstream. In order to protect against speculation attacks on indirect branches, the branch predictor is flushed at kernel entry to protect for the following situations: - userspace process attacking another userspace process - userspace process attacking the kernel Basically when the privillege level change (i.e. the kernel is entered), the branch predictor state is flushed. Signed-off-by: Diana Craciun Signed-off-by: Michael Ellerman Signed-off-by: Greg Kroah-Hartman --- arch/powerpc/kernel/entry_64.S | 5 +++++ arch/powerpc/kernel/exceptions-64e.S | 26 +++++++++++++++++++++++++- arch/powerpc/mm/tlb_low_64e.S | 7 +++++++ 3 files changed, 37 insertions(+), 1 deletion(-) --- a/arch/powerpc/kernel/entry_64.S +++ b/arch/powerpc/kernel/entry_64.S @@ -78,6 +78,11 @@ END_FTR_SECTION_IFSET(CPU_FTR_TM) std r0,GPR0(r1) std r10,GPR1(r1) beq 2f /* if from kernel mode */ +#ifdef CONFIG_PPC_FSL_BOOK3E +START_BTB_FLUSH_SECTION + BTB_FLUSH(r10) +END_BTB_FLUSH_SECTION +#endif ACCOUNT_CPU_USER_ENTRY(r13, r10, r11) 2: std r2,GPR2(r1) std r3,GPR3(r1) --- a/arch/powerpc/kernel/exceptions-64e.S +++ b/arch/powerpc/kernel/exceptions-64e.S @@ -295,7 +295,8 @@ ret_from_mc_except: andi. r10,r11,MSR_PR; /* save stack pointer */ \ beq 1f; /* branch around if supervisor */ \ ld r1,PACAKSAVE(r13); /* get kernel stack coming from usr */\ -1: cmpdi cr1,r1,0; /* check if SP makes sense */ \ +1: type##_BTB_FLUSH \ + cmpdi cr1,r1,0; /* check if SP makes sense */ \ bge- cr1,exc_##n##_bad_stack;/* bad stack (TODO: out of line) */ \ mfspr r10,SPRN_##type##_SRR0; /* read SRR0 before touching stack */ @@ -327,6 +328,29 @@ ret_from_mc_except: #define SPRN_MC_SRR0 SPRN_MCSRR0 #define SPRN_MC_SRR1 SPRN_MCSRR1 +#ifdef CONFIG_PPC_FSL_BOOK3E +#define GEN_BTB_FLUSH \ + START_BTB_FLUSH_SECTION \ + beq 1f; \ + BTB_FLUSH(r10) \ + 1: \ + END_BTB_FLUSH_SECTION + +#define CRIT_BTB_FLUSH \ + START_BTB_FLUSH_SECTION \ + BTB_FLUSH(r10) \ + END_BTB_FLUSH_SECTION + +#define DBG_BTB_FLUSH CRIT_BTB_FLUSH +#define MC_BTB_FLUSH CRIT_BTB_FLUSH +#define GDBELL_BTB_FLUSH GEN_BTB_FLUSH +#else +#define GEN_BTB_FLUSH +#define CRIT_BTB_FLUSH +#define DBG_BTB_FLUSH +#define GDBELL_BTB_FLUSH +#endif + #define NORMAL_EXCEPTION_PROLOG(n, intnum, addition) \ EXCEPTION_PROLOG(n, intnum, GEN, addition##_GEN(n)) --- a/arch/powerpc/mm/tlb_low_64e.S +++ b/arch/powerpc/mm/tlb_low_64e.S @@ -69,6 +69,13 @@ END_FTR_SECTION_IFSET(CPU_FTR_EMB_HV) std r15,EX_TLB_R15(r12) std r10,EX_TLB_CR(r12) #ifdef CONFIG_PPC_FSL_BOOK3E +START_BTB_FLUSH_SECTION + mfspr r11, SPRN_SRR1 + andi. r10,r11,MSR_PR + beq 1f + BTB_FLUSH(r10) +1: +END_BTB_FLUSH_SECTION std r7,EX_TLB_R7(r12) #endif TLB_MISS_PROLOG_STATS