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 80818CCA487 for ; Wed, 20 Jul 2022 01:19:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241492AbiGTBT5 (ORCPT ); Tue, 19 Jul 2022 21:19:57 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48514 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241362AbiGTBSz (ORCPT ); Tue, 19 Jul 2022 21:18:55 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7256FD8F; Tue, 19 Jul 2022 18:15:06 -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 ams.source.kernel.org (Postfix) with ESMTPS id 140A4B81DE3; Wed, 20 Jul 2022 01:14:50 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5BBDAC341CB; Wed, 20 Jul 2022 01:14:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1658279688; bh=tt//DfZUzL9cum2aE1NuqVo8+WIRKq8peSgGbEYXEFQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=eSTwJZCC5AodT2jpb5jdQH0q3AMICxW6oPZF1n6ioOWCiSsrJuF1z9qVWtSewbAi7 Sih6i0+G0xW7mUol9oAltAqBYzEvsJl/wzLWPGJA3grB1o9HbS+ewoueopuMXSFFnY rB97XHnF55CzolBtcV37XbsQZv3LXVEma6qgsMM4aL4rdOCzj2PyslFSTVaZyvWfN/ 245z/K7cBvNYbv2zY5pLCOhltGeuKwDUMsbhw1r6jQzUXWeafOrjMFbkqSrh4Ht84e jN7KAfHXACfcc4N6vnpSKmRa+TMSHnLh+teVjwd6pvvQAsOc4YxGpzXPOpSpHC66oS q5r81Rv7SkhXw== 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, kim.phillips@amd.com, alexandre.chartre@oracle.com, sblbir@amazon.com Subject: [PATCH AUTOSEL 5.15 14/42] x86/bugs: Split spectre_v2_select_mitigation() and spectre_v2_user_select_mitigation() Date: Tue, 19 Jul 2022 21:13:22 -0400 Message-Id: <20220720011350.1024134-14-sashal@kernel.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220720011350.1024134-1-sashal@kernel.org> References: <20220720011350.1024134-1-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 ae7715385153..7637318f3b7e 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