From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AH8x226mPsLEVi1b99pgGl+ltfiZwY6Lfk6Saxw/BIWcBh/fHFhAfiOGQXza5xesfS2w8qpZ0rxQ ARC-Seal: i=1; a=rsa-sha256; t=1516476225; cv=none; d=google.com; s=arc-20160816; b=uYsa9A2urkpNAdR+Sil04grotP9zohPjjsBr/+eeHgRQxEofSZ0ikPh5yS5idi7q2L F6XPWeEL2la8h+6eAB7Idt9c2qXQ5QQPcN53B92pmi2qn6VWk68u9TWZ4QF+IROBoioJ zBA1XavYXua/m+f6r1QEdE+H9Uf7VQ3WAXpcTNiEmfB7oco0D9OJeIMGfIqh54CRHxsF vvtDYaVVygI6G86A7LUQGyUNsBTUgnyEsjgVYajV4uhEMFIykB1eNKAs/SXFc4Aj0MtR 17fT87Gxm07NQexz5wa9ujA8IqMvM2jaYZMn4EfegYH+kd3+dBcnw9oQe+Tcxt9xVgNk 1a7w== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=references:in-reply-to:message-id:date:subject:cc:to:from :dkim-signature:arc-authentication-results; bh=ZUBs/+GJjylx+r7QkS+h3/vptWiEKpiLTyKIpNbgITM=; b=ppjXyrIMA2MULPLs7eyKbGWeUCuHeqbA11sYlJKWc38t/zrgBIJLPizbHcwHFd/pzG ApiREATqh5zaHu2nWjDci/Y/I13GGd+GrG7zyouQ4Gk8BqpNOPZcv3LiZ6JtRp11hKBg th4S0vYslMMIuXWeRK3kOHly8HW95xwc7XaPIqUzv5rlaD+p5koaPAej1xNK8fEvPOJP myRVOFabdnh5wrO6NXA8WQEgc/f1WwAXP72whfDtNulgWtPx9LDHhgIj1Ii4NfIuZktz 3SO9UEuHBhjcu6P3hndb+bzlUNSgm8Ag2MqLYj0OCHibn/+FUIuxSJDme84byPb4jJ3p 99pA== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@amazon.de header.s=amazon201209 header.b=EFGCrw+s; spf=pass (google.com: domain of prvs=551b82ed1=karahmed@amazon.com designates 207.171.190.10 as permitted sender) smtp.mailfrom=prvs=551b82ed1=karahmed@amazon.com; dmarc=pass (p=QUARANTINE sp=QUARANTINE dis=NONE) header.from=amazon.de Authentication-Results: mx.google.com; dkim=pass header.i=@amazon.de header.s=amazon201209 header.b=EFGCrw+s; spf=pass (google.com: domain of prvs=551b82ed1=karahmed@amazon.com designates 207.171.190.10 as permitted sender) smtp.mailfrom=prvs=551b82ed1=karahmed@amazon.com; dmarc=pass (p=QUARANTINE sp=QUARANTINE dis=NONE) header.from=amazon.de X-IronPort-AV: E=Sophos;i="5.46,387,1511827200"; d="scan'208";a="716423186" From: KarimAllah Ahmed To: linux-kernel@vger.kernel.org Cc: KarimAllah Ahmed , Andi Kleen , Andrea Arcangeli , Andy Lutomirski , Arjan van de Ven , Ashok Raj , Asit Mallick , Borislav Petkov , Dan Williams , Dave Hansen , David Woodhouse , Greg Kroah-Hartman , "H . Peter Anvin" , Ingo Molnar , Janakarajan Natarajan , Joerg Roedel , Jun Nakajima , Laura Abbott , Linus Torvalds , Masami Hiramatsu , Paolo Bonzini , Peter Zijlstra , =?UTF-8?q?Radim=20Kr=C4=8Dm=C3=A1=C5=99?= , Thomas Gleixner , Tim Chen , Tom Lendacky , kvm@vger.kernel.org, x86@kernel.org Subject: [RFC 07/10] x86: Simplify spectre_v2 command line parsing Date: Sat, 20 Jan 2018 20:22:58 +0100 Message-Id: <1516476182-5153-8-git-send-email-karahmed@amazon.de> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1516476182-5153-1-git-send-email-karahmed@amazon.de> References: <1516476182-5153-1-git-send-email-karahmed@amazon.de> X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: =?utf-8?q?1590140575000429454?= X-GMAIL-MSGID: =?utf-8?q?1590140575000429454?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: Signed-off-by: KarimAllah Ahmed --- arch/x86/kernel/cpu/bugs.c | 106 +++++++++++++++++++++++++-------------------- 1 file changed, 58 insertions(+), 48 deletions(-) diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c index 1d5e12f..349c7f4 100644 --- a/arch/x86/kernel/cpu/bugs.c +++ b/arch/x86/kernel/cpu/bugs.c @@ -99,13 +99,13 @@ static enum spectre_v2_mitigation spectre_v2_enabled = SPECTRE_V2_NONE; static void __init spec2_print_if_insecure(const char *reason) { if (boot_cpu_has_bug(X86_BUG_SPECTRE_V2)) - pr_info("%s\n", reason); + pr_info("%s selected on command line.\n", reason); } static void __init spec2_print_if_secure(const char *reason) { if (!boot_cpu_has_bug(X86_BUG_SPECTRE_V2)) - pr_info("%s\n", reason); + pr_info("%s selected on command line.\n", reason); } static inline bool retp_compiler(void) @@ -120,61 +120,71 @@ static inline bool match_option(const char *arg, int arglen, const char *opt) return len == arglen && !strncmp(arg, opt, len); } +static struct { + char *option; + enum spectre_v2_mitigation_cmd cmd; + bool secure; +} mitigation_options[] = { + { "off", SPECTRE_V2_CMD_NONE, false }, + { "on", SPECTRE_V2_CMD_FORCE, true }, + { "retpoline", SPECTRE_V2_CMD_RETPOLINE, false }, + { "retpoline,amd", SPECTRE_V2_CMD_RETPOLINE_AMD, false }, + { "retpoline,generic", SPECTRE_V2_CMD_RETPOLINE_GENERIC, false }, + { "ibrs", SPECTRE_V2_CMD_IBRS, false }, + { "auto", SPECTRE_V2_CMD_AUTO, false }, +}; + +static const int mitigation_options_count = sizeof(mitigation_options) / + sizeof(mitigation_options[0]); + static enum spectre_v2_mitigation_cmd __init spectre_v2_parse_cmdline(void) { char arg[20]; - int ret; + int ret, i; + enum spectre_v2_mitigation_cmd cmd = SPECTRE_V2_CMD_AUTO; + + if (cmdline_find_option_bool(boot_command_line, "nospectre_v2")) + return SPECTRE_V2_CMD_NONE; ret = cmdline_find_option(boot_command_line, "spectre_v2", arg, sizeof(arg)); - if (ret > 0) { - if (match_option(arg, ret, "off")) { - goto disable; - } else if (match_option(arg, ret, "on")) { - spec2_print_if_secure("force enabled on command line."); - return SPECTRE_V2_CMD_FORCE; - } else if (match_option(arg, ret, "retpoline")) { - if (!IS_ENABLED(CONFIG_RETPOLINE)) { - pr_err("retpoline selected but not compiled in. Switching to AUTO select\n"); - return SPECTRE_V2_CMD_AUTO; - } - spec2_print_if_insecure("retpoline selected on command line."); - return SPECTRE_V2_CMD_RETPOLINE; - } else if (match_option(arg, ret, "retpoline,amd")) { - if (!IS_ENABLED(CONFIG_RETPOLINE)) { - pr_err("retpoline,amd selected but not compiled in. Switching to AUTO select\n"); - return SPECTRE_V2_CMD_AUTO; - } - if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD) { - pr_err("retpoline,amd selected but CPU is not AMD. Switching to AUTO select\n"); - return SPECTRE_V2_CMD_AUTO; - } - spec2_print_if_insecure("AMD retpoline selected on command line."); - return SPECTRE_V2_CMD_RETPOLINE_AMD; - } else if (match_option(arg, ret, "retpoline,generic")) { - if (!IS_ENABLED(CONFIG_RETPOLINE)) { - pr_err("retpoline,generic selected but not compiled in. Switching to AUTO select\n"); - return SPECTRE_V2_CMD_AUTO; - } - spec2_print_if_insecure("generic retpoline selected on command line."); - return SPECTRE_V2_CMD_RETPOLINE_GENERIC; - } else if (match_option(arg, ret, "ibrs")) { - if (!boot_cpu_has(X86_FEATURE_SPEC_CTRL)) { - pr_err("IBRS selected but no CPU support. Switching to AUTO select\n"); - return SPECTRE_V2_CMD_AUTO; - } - spec2_print_if_insecure("IBRS seleted on command line."); - return SPECTRE_V2_CMD_IBRS; - } else if (match_option(arg, ret, "auto")) { - return SPECTRE_V2_CMD_AUTO; - } + if (ret < 0) + return SPECTRE_V2_CMD_AUTO; + + for (i = 0; i < mitigation_options_count; i++) { + if (!match_option(arg, ret, mitigation_options[i].option)) + continue; + cmd = mitigation_options[i].cmd; + break; } - if (!cmdline_find_option_bool(boot_command_line, "nospectre_v2")) + if (i >= mitigation_options_count) { + pr_err("unknown option (%s). Switching to AUTO select\n", + mitigation_options[i].option); return SPECTRE_V2_CMD_AUTO; -disable: - spec2_print_if_insecure("disabled on command line."); - return SPECTRE_V2_CMD_NONE; + } + + if ((cmd == SPECTRE_V2_CMD_RETPOLINE || + cmd == SPECTRE_V2_CMD_RETPOLINE_AMD || + cmd == SPECTRE_V2_CMD_RETPOLINE_GENERIC) && + !IS_ENABLED(CONFIG_RETPOLINE)) { + pr_err("%s selected but not compiled in. Switching to AUTO select\n", + mitigation_options[i].option); + return SPECTRE_V2_CMD_AUTO; + } + + if (cmd == SPECTRE_V2_CMD_RETPOLINE_AMD && + boot_cpu_data.x86_vendor != X86_VENDOR_AMD) { + pr_err("retpoline,amd selected but CPU is not AMD. Switching to AUTO select\n"); + return SPECTRE_V2_CMD_AUTO; + } + + if (mitigation_options[i].secure) + spec2_print_if_secure(mitigation_options[i].option); + else + spec2_print_if_insecure(mitigation_options[i].option); + + return cmd; } /* Check for Skylake-like CPUs (for RSB and IBRS handling) */ -- 2.7.4