From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ozlabs.org (ozlabs.org [IPv6:2401:3900:2:1::2]) (using TLSv1.2 with cipher ADH-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3zt7BC3SMCzF1rc for ; Fri, 2 Mar 2018 22:58:59 +1100 (AEDT) From: Michael Ellerman To: linuxppc-dev@ozlabs.org Subject: [RFC PATCH 10/10] powerpc/64s: Wire up cpu_show_spectre_v2() Date: Fri, 2 Mar 2018 22:58:46 +1100 Message-Id: <20180302115846.12240-4-mpe@ellerman.id.au> In-Reply-To: <20180302115846.12240-1-mpe@ellerman.id.au> References: <20180228145316.11347-1-mpe@ellerman.id.au> <20180302115846.12240-1-mpe@ellerman.id.au> List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Add a definition for cpu_show_spectre_v2() to override the generic version. This has several permuations, though in practice some may not occur we cater for any combination. The most verbose is: Mitigation: Indirect branch serialisation (kernel only), Indirect branch cache disabled, ori31 speculation barrier enabled We don't treat the ori31 speculation barrier as a mitigation on its own, because it has to be *used* by code in order to be a mitigation and we don't know if userspace is doing that. So if that's all we see we say: Vulnerable, ori31 speculation barrier enabled Signed-off-by: Michael Ellerman --- arch/powerpc/kernel/security.c | 33 +++++++++++++++++++++++++++++++++ 1 file changed, 33 insertions(+) diff --git a/arch/powerpc/kernel/security.c b/arch/powerpc/kernel/security.c index 0eace3cac818..2cee3dcd231b 100644 --- a/arch/powerpc/kernel/security.c +++ b/arch/powerpc/kernel/security.c @@ -58,3 +58,36 @@ ssize_t cpu_show_spectre_v1(struct device *dev, struct device_attribute *attr, c return sprintf(buf, "Vulnerable\n"); } + +ssize_t cpu_show_spectre_v2(struct device *dev, struct device_attribute *attr, char *buf) +{ + bool bcs, ccd, ori; + struct seq_buf s; + + seq_buf_init(&s, buf, PAGE_SIZE - 1); + + bcs = security_ftr_enabled(SEC_FTR_BCCTRL_SERIALISED); + ccd = security_ftr_enabled(SEC_FTR_COUNT_CACHE_DISABLED); + ori = security_ftr_enabled(SEC_FTR_SPEC_BAR_ORI31); + + if (bcs || ccd) { + seq_buf_printf(&s, "Mitigation: "); + + if (bcs) + seq_buf_printf(&s, "Indirect branch serialisation (kernel only)"); + + if (bcs && ccd) + seq_buf_printf(&s, ", "); + + if (ccd) + seq_buf_printf(&s, "Indirect branch cache disabled"); + } else + seq_buf_printf(&s, "Vulnerable"); + + if (ori) + seq_buf_printf(&s, ", ori31 speculation barrier enabled"); + + seq_buf_printf(&s, "\n"); + + return s.len; +} -- 2.14.1