From: Michael Ellerman <mpe@ellerman.id.au>
To: greg@kroah.com
Cc: stable@vger.kernel.org, tglx@linutronix.de, linuxppc-dev@ozlabs.org
Subject: [PATCH stable 4.16 11/14] powerpc/64s: Wire up cpu_show_spectre_v2()
Date: Wed, 23 May 2018 00:41:22 +1000 [thread overview]
Message-ID: <20180522144125.10345-12-mpe@ellerman.id.au> (raw)
In-Reply-To: <20180522144125.10345-1-mpe@ellerman.id.au>
commit d6fbe1c55c55c6937cbea3531af7da84ab7473c3 upstream.
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 <mpe@ellerman.id.au>
---
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
next prev parent reply other threads:[~2018-05-22 14:42 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-05-22 14:41 [PATCH stable 4.16 00/14] powerpc backports for 4.16 Michael Ellerman
2018-05-22 14:41 ` [PATCH stable 4.16 01/14] powerpc/rfi-flush: Always enable fallback flush on pseries Michael Ellerman
2018-05-23 17:23 ` Patch "powerpc/rfi-flush: Always enable fallback flush on pseries" has been added to the 4.16-stable tree gregkh
2018-05-22 14:41 ` [PATCH stable 4.16 02/14] powerpc: Add security feature flags for Spectre/Meltdown Michael Ellerman
2018-05-23 17:23 ` Patch "powerpc: Add security feature flags for Spectre/Meltdown" has been added to the 4.16-stable tree gregkh
2018-05-22 14:41 ` [PATCH stable 4.16 03/14] powerpc/pseries: Add new H_GET_CPU_CHARACTERISTICS flags Michael Ellerman
2018-05-23 17:23 ` Patch "powerpc/pseries: Add new H_GET_CPU_CHARACTERISTICS flags" has been added to the 4.16-stable tree gregkh
2018-05-22 14:41 ` [PATCH stable 4.16 04/14] powerpc/pseries: Set or clear security feature flags Michael Ellerman
2018-05-23 17:23 ` Patch "powerpc/pseries: Set or clear security feature flags" has been added to the 4.16-stable tree gregkh
2018-05-22 14:41 ` [PATCH stable 4.16 05/14] powerpc/powernv: Set or clear security feature flags Michael Ellerman
2018-05-23 17:23 ` Patch "powerpc/powernv: Set or clear security feature flags" has been added to the 4.16-stable tree gregkh
2018-05-22 14:41 ` [PATCH stable 4.16 06/14] powerpc/64s: Move cpu_show_meltdown() Michael Ellerman
2018-05-23 17:23 ` Patch "powerpc/64s: Move cpu_show_meltdown()" has been added to the 4.16-stable tree gregkh
2018-05-22 14:41 ` [PATCH stable 4.16 07/14] powerpc/64s: Enhance the information in cpu_show_meltdown() Michael Ellerman
2018-05-23 17:23 ` Patch "powerpc/64s: Enhance the information in cpu_show_meltdown()" has been added to the 4.16-stable tree gregkh
2018-05-22 14:41 ` [PATCH stable 4.16 08/14] powerpc/powernv: Use the security flags in pnv_setup_rfi_flush() Michael Ellerman
2018-05-23 17:23 ` Patch "powerpc/powernv: Use the security flags in pnv_setup_rfi_flush()" has been added to the 4.16-stable tree gregkh
2018-05-22 14:41 ` [PATCH stable 4.16 09/14] powerpc/pseries: Use the security flags in pseries_setup_rfi_flush() Michael Ellerman
2018-05-23 17:23 ` Patch "powerpc/pseries: Use the security flags in pseries_setup_rfi_flush()" has been added to the 4.16-stable tree gregkh
2018-05-22 14:41 ` [PATCH stable 4.16 10/14] powerpc/64s: Wire up cpu_show_spectre_v1() Michael Ellerman
2018-05-23 17:23 ` Patch "powerpc/64s: Wire up cpu_show_spectre_v1()" has been added to the 4.16-stable tree gregkh
2018-05-22 14:41 ` Michael Ellerman [this message]
2018-05-23 17:23 ` Patch "powerpc/64s: Wire up cpu_show_spectre_v2()" " gregkh
2018-05-22 14:41 ` [PATCH stable 4.16 12/14] powerpc/pseries: Fix clearing of security feature flags Michael Ellerman
2018-05-23 17:23 ` Patch "powerpc/pseries: Fix clearing of security feature flags" has been added to the 4.16-stable tree gregkh
2018-05-22 14:41 ` [PATCH stable 4.16 13/14] powerpc: Move default security feature flags Michael Ellerman
2018-05-23 17:23 ` Patch "powerpc: Move default security feature flags" has been added to the 4.16-stable tree gregkh
2018-05-22 14:41 ` [PATCH stable 4.16 14/14] powerpc/64s: Add support for a store forwarding barrier at kernel entry/exit Michael Ellerman
2018-05-23 17:23 ` Patch "powerpc/64s: Add support for a store forwarding barrier at kernel entry/exit" has been added to the 4.16-stable tree gregkh
2018-05-23 17:21 ` [PATCH stable 4.16 00/14] powerpc backports for 4.16 Greg KH
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