From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AH8x225hStUzP32ZOMaNbnRHy1dhfowaU/UFXgl+ahY2Xl0Ig5xCup4iWBP8btYcXhgHeNPnpzsn ARC-Seal: i=1; a=rsa-sha256; t=1517855162; cv=none; d=google.com; s=arc-20160816; b=NCjXAiHafzYH/ZpNZPRFYPDWELhITDdRP4TV0SZz1fcJDd4nlVtiHcQKRhrmRNhaBY Prya/wMbniE5eN2FMWYG+BBK5X6h/SXe/hcM9dECdVISk1bP4wRUwiHcbKMjNstQ9WfP jpMTWZBejmfWBGkvK0ilzPwgh+PWa0666R3NKn4hNXf+xjCJ2oIv9xoUSH/ydO8AmH6L jGshRpukV2IrmZF9KJaSAGvv2eKEYbT8TMFW7be/8wQFWCI+3NpkEgMPHQP/1SEcmLkk lxKvdl44J125/6wX3kANSGMK1OCNKFScMuQXXGRxwX2cSyGUn6itm80RBoXZXlfFAedP KUbw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=mime-version:user-agent:references:in-reply-to:message-id:date :subject:cc:to:from:arc-authentication-results; bh=T1MguqecCA2RPHfwzb6EPf54I4dFPbqNU45oiKWjM7o=; b=R98TrEzRZJ/DSeF8kioBfjffTFQekYBAzbzdGv+NlT0LymmAZAzyVRwLKx2mNTclHw Em9YkDv2YUUiRX4Nc7udSou6TVpomGDrDo25L6LNAfz3k+gKYl6MXlv/FUHVJ0p3qsvH O0cUeb6Nf+cOVCu2SijmK/sKaJkK2wAoVbaVY0AYbiuwdfi/Onr9NxA9BxEYskr9WNiq 6cW5tACpo6ulUa9frn+1USpZ7MWdpJOgdvdAHQTjfHCbgNeq4INTZ978zQIIGsYzDSkv 7XzOdWDw5G288gg5+DTJaYJXEckwLTeRqCY7AKBnUrVGGm6u384ZVKhhh8wwpoQrjNH5 txCg== ARC-Authentication-Results: i=1; mx.google.com; spf=softfail (google.com: domain of transitioning gregkh@linuxfoundation.org does not designate 104.132.1.108 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org Authentication-Results: mx.google.com; spf=softfail (google.com: domain of transitioning gregkh@linuxfoundation.org does not designate 104.132.1.108 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, KarimAllah Ahmed , David Woodhouse , Thomas Gleixner , peterz@infradead.org, bp@alien8.de Subject: [PATCH 4.15 51/60] x86/spectre: Simplify spectre_v2 command line parsing Date: Mon, 5 Feb 2018 10:23:24 -0800 Message-Id: <20180205182216.343466931@linuxfoundation.org> X-Mailer: git-send-email 2.16.1 In-Reply-To: <20180205182213.902626065@linuxfoundation.org> References: <20180205182213.902626065@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-LABELS: =?utf-8?b?IlxcU2VudCI=?= X-GMAIL-THRID: =?utf-8?q?1591586400224596220?= X-GMAIL-MSGID: =?utf-8?q?1591586494918116569?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 4.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: KarimAllah Ahmed karahmed@amazon.de commit 9005c6834c0ffdfe46afa76656bd9276cca864f6 [dwmw2: Use ARRAY_SIZE] Signed-off-by: KarimAllah Ahmed Signed-off-by: David Woodhouse Signed-off-by: Thomas Gleixner Cc: peterz@infradead.org Cc: bp@alien8.de Link: https://lkml.kernel.org/r/1517484441-1420-3-git-send-email-dwmw@amazon.co.uk Signed-off-by: Greg Kroah-Hartman --- arch/x86/kernel/cpu/bugs.c | 84 +++++++++++++++++++++++++++++---------------- 1 file changed, 55 insertions(+), 29 deletions(-) --- a/arch/x86/kernel/cpu/bugs.c +++ b/arch/x86/kernel/cpu/bugs.c @@ -119,13 +119,13 @@ static inline const char *spectre_v2_mod 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) @@ -140,42 +140,68 @@ static inline bool match_option(const ch return len == arglen && !strncmp(arg, opt, len); } +static const struct { + const 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 }, + { "auto", SPECTRE_V2_CMD_AUTO, false }, +}; + 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; + else { + ret = cmdline_find_option(boot_command_line, "spectre_v2", arg, + sizeof(arg)); + if (ret < 0) + return SPECTRE_V2_CMD_AUTO; - 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")) { - spec2_print_if_insecure("retpoline selected on command line."); - return SPECTRE_V2_CMD_RETPOLINE; - } else if (match_option(arg, ret, "retpoline,amd")) { - 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")) { - spec2_print_if_insecure("generic retpoline selected on command line."); - return SPECTRE_V2_CMD_RETPOLINE_GENERIC; - } else if (match_option(arg, ret, "auto")) { + for (i = 0; i < ARRAY_SIZE(mitigation_options); i++) { + if (!match_option(arg, ret, mitigation_options[i].option)) + continue; + cmd = mitigation_options[i].cmd; + break; + } + + if (i >= ARRAY_SIZE(mitigation_options)) { + pr_err("unknown option (%s). Switching to AUTO select\n", + mitigation_options[i].option); return SPECTRE_V2_CMD_AUTO; } } - if (!cmdline_find_option_bool(boot_command_line, "nospectre_v2")) + 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; -disable: - spec2_print_if_insecure("disabled on command line."); - return SPECTRE_V2_CMD_NONE; + } + + 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 handling) */