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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1387CC433EF for ; Wed, 20 Jul 2022 01:12:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240754AbiGTBMn (ORCPT ); Tue, 19 Jul 2022 21:12:43 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33356 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240519AbiGTBMP (ORCPT ); Tue, 19 Jul 2022 21:12:15 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 186D9664FC; Tue, 19 Jul 2022 18:11:53 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 8A93C61384; Wed, 20 Jul 2022 01:11:52 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7ADCFC341C6; Wed, 20 Jul 2022 01:11:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1658279512; bh=0Qr97Syi6E4vRW6NBm4l2vDXMFIe+WrnluOYgtacz94=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=hOV9kTOkHEKQNGDyzb+OmnY3Alv2I5uG+CBl5j9EXG1yIMddMvntqF8PISslwOnXn OsSYUzIYaa7KLns4FFhS9mSEEOzSxW30ujwmyC4u4eOXpuubzZlbpHV2p5JMjsPyHa CZslXNfGUVmece6XvHtLAHCgYVrMO+RLFWBLJmzKJ3ZOEm747DNjvwrteohzQ05mjW TK7UYwjQq/C78Skr0V2pnTHqY7I0uPPwof+eWsJeQf6lIFeac8C8amsxbGrmta1NiB hXnGhBDDtcEQ0Yo8CSzyxs6E7z0+NLJDE466bmIW+9ox7u+Yp7fX+/Ckfa+hnlU0m5 vLP2/wpIcGQAA== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Peter Zijlstra , Borislav Petkov , Josh Poimboeuf , Sasha Levin , tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, x86@kernel.org, pawan.kumar.gupta@linux.intel.com, sblbir@amazon.com, alexandre.chartre@oracle.com, kim.phillips@amd.com Subject: [PATCH AUTOSEL 5.18 18/54] x86/bugs: Split spectre_v2_select_mitigation() and spectre_v2_user_select_mitigation() Date: Tue, 19 Jul 2022 21:09:55 -0400 Message-Id: <20220720011031.1023305-18-sashal@kernel.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220720011031.1023305-1-sashal@kernel.org> References: <20220720011031.1023305-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Peter Zijlstra [ Upstream commit 166115c08a9b0b846b783088808a27d739be6e8d ] retbleed will depend on spectre_v2, while spectre_v2_user depends on retbleed. Break this cycle. Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Borislav Petkov Reviewed-by: Josh Poimboeuf Signed-off-by: Borislav Petkov Signed-off-by: Sasha Levin --- arch/x86/kernel/cpu/bugs.c | 25 +++++++++++++++++-------- 1 file changed, 17 insertions(+), 8 deletions(-) diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c index 9defb942e941..a9ef81e83f28 100644 --- a/arch/x86/kernel/cpu/bugs.c +++ b/arch/x86/kernel/cpu/bugs.c @@ -37,8 +37,9 @@ #include "cpu.h" static void __init spectre_v1_select_mitigation(void); -static void __init retbleed_select_mitigation(void); static void __init spectre_v2_select_mitigation(void); +static void __init retbleed_select_mitigation(void); +static void __init spectre_v2_user_select_mitigation(void); static void __init ssb_select_mitigation(void); static void __init l1tf_select_mitigation(void); static void __init mds_select_mitigation(void); @@ -145,13 +146,19 @@ void __init check_bugs(void) /* Select the proper CPU mitigations before patching alternatives: */ spectre_v1_select_mitigation(); + spectre_v2_select_mitigation(); + /* + * retbleed_select_mitigation() relies on the state set by + * spectre_v2_select_mitigation(); specifically it wants to know about + * spectre_v2=ibrs. + */ retbleed_select_mitigation(); /* - * spectre_v2_select_mitigation() relies on the state set by + * spectre_v2_user_select_mitigation() relies on the state set by * retbleed_select_mitigation(); specifically the STIBP selection is * forced for UNRET. */ - spectre_v2_select_mitigation(); + spectre_v2_user_select_mitigation(); ssb_select_mitigation(); l1tf_select_mitigation(); md_clear_select_mitigation(); @@ -1005,13 +1012,15 @@ static void __init spec_v2_user_print_cond(const char *reason, bool secure) pr_info("spectre_v2_user=%s forced on command line.\n", reason); } +static __ro_after_init enum spectre_v2_mitigation_cmd spectre_v2_cmd; + static enum spectre_v2_user_cmd __init -spectre_v2_parse_user_cmdline(enum spectre_v2_mitigation_cmd v2_cmd) +spectre_v2_parse_user_cmdline(void) { char arg[20]; int ret, i; - switch (v2_cmd) { + switch (spectre_v2_cmd) { case SPECTRE_V2_CMD_NONE: return SPECTRE_V2_USER_CMD_NONE; case SPECTRE_V2_CMD_FORCE: @@ -1045,7 +1054,7 @@ static inline bool spectre_v2_in_eibrs_mode(enum spectre_v2_mitigation mode) } static void __init -spectre_v2_user_select_mitigation(enum spectre_v2_mitigation_cmd v2_cmd) +spectre_v2_user_select_mitigation(void) { enum spectre_v2_user_mitigation mode = SPECTRE_V2_USER_NONE; bool smt_possible = IS_ENABLED(CONFIG_SMP); @@ -1058,7 +1067,7 @@ spectre_v2_user_select_mitigation(enum spectre_v2_mitigation_cmd v2_cmd) cpu_smt_control == CPU_SMT_NOT_SUPPORTED) smt_possible = false; - cmd = spectre_v2_parse_user_cmdline(v2_cmd); + cmd = spectre_v2_parse_user_cmdline(); switch (cmd) { case SPECTRE_V2_USER_CMD_NONE: goto set_mode; @@ -1346,7 +1355,7 @@ static void __init spectre_v2_select_mitigation(void) } /* Set up IBPB and STIBP depending on the general spectre V2 command */ - spectre_v2_user_select_mitigation(cmd); + spectre_v2_cmd = cmd; } static void update_stibp_msr(void * __unused) -- 2.35.1