From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AH8x225gl9BCxH0b2EHeUuNAemfHTNOVteELkzkqCztYDGsiDMKLkP3FBXmBqZHYequsRroW6nWx ARC-Seal: i=1; a=rsa-sha256; t=1517855109; cv=none; d=google.com; s=arc-20160816; b=kciAqQP7oCRP8Ws/mTmBWBJa9dmUcKOviQF9rlg8k8rXMCCdCiyTrB5oroxFN3RMVU kVSCdRxXQ4/BhOPo4iXomAjVvfjkp1Nv41HBoBCUOfJwGKbrrflbpvKKc20VwEtPtoiY 00GglTsz08LdYy1go2dXd/Pf3scXEmUrXYmzH5s4pxqK5lcvjqIXwvc9Knk4Azb86Y3c Sk8/MmqWU6vXqmv6MDRwSYpLDJ/hXzLVq0gbywXnrn3wgrqzEUbDuZquevU3vt19KV7X NNZQ8R/iI37QqfoB94Ubj/DEsUVZQ8eOC8Kg3D0JB9qYpwvZVQUxEu1nYwx/iBTeIb0L TR9Q== 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=wn4/Y5s15j2exljyjEC6P+eWAjeeoEfvcPRWBYzC07I=; b=Ds6LpWG1WYXrOmkRPuUVpqfUjhjeXNAHnWNfRbDHcxpgsGJFwolChrF92dPmqO8lr2 UxFsiAMXcKmtC79ts9cMJOxuE8zP+5mc/ESmcm8oTL3lijK+7oAacZatI1Hn/70hx46E CkE+VI3z6qNEYik7S652pHOZLwP1kjvqmqwLT+IT078csuV+UxnvHTWnaXB1rOWBlJHE RsXXg6p4pjL3RqYLb2QRUhzHufQVpBxQRtfkdUnACcfAekq/VrkG4NSwrArGiSz3DP3p JYTUC4qj72H+gFaHMbBvy57PVw8gXMWB8edRYgfbbewjyQYae20sXpoi/JEDpckpD9wS lWJw== 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, David Woodhouse , Thomas Gleixner , gnomes@lxorguk.ukuu.org.uk, ak@linux.intel.com, ashok.raj@intel.com, dave.hansen@intel.com, karahmed@amazon.de, arjan@linux.intel.com, torvalds@linux-foundation.org, peterz@infradead.org, bp@alien8.de, pbonzini@redhat.com, tim.c.chen@linux.intel.com, gregkh@linux-foundation.org Subject: [PATCH 4.15 09/60] x86/cpufeature: Blacklist SPEC_CTRL/PRED_CMD on early Spectre v2 microcodes Date: Mon, 5 Feb 2018 10:22:42 -0800 Message-Id: <20180205182214.305086493@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?1591586336170736700?= X-GMAIL-MSGID: =?utf-8?q?1591586438786121742?= 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: David Woodhouse dwmw@amazon.co.uk commit a5b2966364538a0e68c9fa29bc0a3a1651799035 This doesn't refuse to load the affected microcodes; it just refuses to use the Spectre v2 mitigation features if they're detected, by clearing the appropriate feature bits. The AMD CPUID bits are handled here too, because hypervisors *may* have been exposing those bits even on Intel chips, for fine-grained control of what's available. It is non-trivial to use x86_match_cpu() for this table because that doesn't handle steppings. And the approach taken in commit bd9240a18 almost made me lose my lunch. Signed-off-by: David Woodhouse Signed-off-by: Thomas Gleixner Reviewed-by: Greg Kroah-Hartman Cc: gnomes@lxorguk.ukuu.org.uk Cc: ak@linux.intel.com Cc: ashok.raj@intel.com Cc: dave.hansen@intel.com Cc: karahmed@amazon.de Cc: arjan@linux.intel.com Cc: torvalds@linux-foundation.org Cc: peterz@infradead.org Cc: bp@alien8.de Cc: pbonzini@redhat.com Cc: tim.c.chen@linux.intel.com Cc: gregkh@linux-foundation.org Link: https://lkml.kernel.org/r/1516896855-7642-7-git-send-email-dwmw@amazon.co.uk Signed-off-by: Greg Kroah-Hartman --- arch/x86/kernel/cpu/intel.c | 66 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 66 insertions(+) --- a/arch/x86/kernel/cpu/intel.c +++ b/arch/x86/kernel/cpu/intel.c @@ -102,6 +102,59 @@ static void probe_xeon_phi_r3mwait(struc ELF_HWCAP2 |= HWCAP2_RING3MWAIT; } +/* + * Early microcode releases for the Spectre v2 mitigation were broken. + * Information taken from; + * - https://newsroom.intel.com/wp-content/uploads/sites/11/2018/01/microcode-update-guidance.pdf + * - https://kb.vmware.com/s/article/52345 + * - Microcode revisions observed in the wild + * - Release note from 20180108 microcode release + */ +struct sku_microcode { + u8 model; + u8 stepping; + u32 microcode; +}; +static const struct sku_microcode spectre_bad_microcodes[] = { + { INTEL_FAM6_KABYLAKE_DESKTOP, 0x0B, 0x84 }, + { INTEL_FAM6_KABYLAKE_DESKTOP, 0x0A, 0x84 }, + { INTEL_FAM6_KABYLAKE_DESKTOP, 0x09, 0x84 }, + { INTEL_FAM6_KABYLAKE_MOBILE, 0x0A, 0x84 }, + { INTEL_FAM6_KABYLAKE_MOBILE, 0x09, 0x84 }, + { INTEL_FAM6_SKYLAKE_X, 0x03, 0x0100013e }, + { INTEL_FAM6_SKYLAKE_X, 0x04, 0x0200003c }, + { INTEL_FAM6_SKYLAKE_MOBILE, 0x03, 0xc2 }, + { INTEL_FAM6_SKYLAKE_DESKTOP, 0x03, 0xc2 }, + { INTEL_FAM6_BROADWELL_CORE, 0x04, 0x28 }, + { INTEL_FAM6_BROADWELL_GT3E, 0x01, 0x1b }, + { INTEL_FAM6_BROADWELL_XEON_D, 0x02, 0x14 }, + { INTEL_FAM6_BROADWELL_XEON_D, 0x03, 0x07000011 }, + { INTEL_FAM6_BROADWELL_X, 0x01, 0x0b000025 }, + { INTEL_FAM6_HASWELL_ULT, 0x01, 0x21 }, + { INTEL_FAM6_HASWELL_GT3E, 0x01, 0x18 }, + { INTEL_FAM6_HASWELL_CORE, 0x03, 0x23 }, + { INTEL_FAM6_HASWELL_X, 0x02, 0x3b }, + { INTEL_FAM6_HASWELL_X, 0x04, 0x10 }, + { INTEL_FAM6_IVYBRIDGE_X, 0x04, 0x42a }, + /* Updated in the 20180108 release; blacklist until we know otherwise */ + { INTEL_FAM6_ATOM_GEMINI_LAKE, 0x01, 0x22 }, + /* Observed in the wild */ + { INTEL_FAM6_SANDYBRIDGE_X, 0x06, 0x61b }, + { INTEL_FAM6_SANDYBRIDGE_X, 0x07, 0x712 }, +}; + +static bool bad_spectre_microcode(struct cpuinfo_x86 *c) +{ + int i; + + for (i = 0; i < ARRAY_SIZE(spectre_bad_microcodes); i++) { + if (c->x86_model == spectre_bad_microcodes[i].model && + c->x86_mask == spectre_bad_microcodes[i].stepping) + return (c->microcode <= spectre_bad_microcodes[i].microcode); + } + return false; +} + static void early_init_intel(struct cpuinfo_x86 *c) { u64 misc_enable; @@ -122,6 +175,19 @@ static void early_init_intel(struct cpui if (c->x86 >= 6 && !cpu_has(c, X86_FEATURE_IA64)) c->microcode = intel_get_microcode_revision(); + if ((cpu_has(c, X86_FEATURE_SPEC_CTRL) || + cpu_has(c, X86_FEATURE_STIBP) || + cpu_has(c, X86_FEATURE_AMD_SPEC_CTRL) || + cpu_has(c, X86_FEATURE_AMD_PRED_CMD) || + cpu_has(c, X86_FEATURE_AMD_STIBP)) && bad_spectre_microcode(c)) { + pr_warn("Intel Spectre v2 broken microcode detected; disabling SPEC_CTRL\n"); + clear_cpu_cap(c, X86_FEATURE_SPEC_CTRL); + clear_cpu_cap(c, X86_FEATURE_STIBP); + clear_cpu_cap(c, X86_FEATURE_AMD_SPEC_CTRL); + clear_cpu_cap(c, X86_FEATURE_AMD_PRED_CMD); + clear_cpu_cap(c, X86_FEATURE_AMD_STIBP); + } + /* * Atom erratum AAE44/AAF40/AAG38/AAH41: *