Patch "arm64: ssbs: Don't treat CPUs with SSBS as unaffected by SSB" has been added to the 4.19-stable tree

[<gregkh@linuxfoundation.org>]

This is a note to let you know that I've just added the patch titled

    arm64: ssbs: Don't treat CPUs with SSBS as unaffected by SSB

to the 4.19-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     arm64-ssbs-don-t-treat-cpus-with-ssbs-as-unaffected-by-ssb.patch
and it can be found in the queue-4.19 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


From foo@baz Wed 09 Oct 2019 10:02:12 AM CEST
From: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Date: Tue,  8 Oct 2019 17:39:29 +0200
Subject: arm64: ssbs: Don't treat CPUs with SSBS as unaffected by SSB
To: linux-arm-kernel@lists.infradead.org
Cc: stable@vger.kernel.org, Will Deacon <will.deacon@arm.com>, Ard Biesheuvel <ard.biesheuvel@linaro.org>
Message-ID: <20191008153930.15386-16-ard.biesheuvel@linaro.org>

From: Will Deacon <will.deacon@arm.com>

[ Upstream commit eb337cdfcd5dd3b10522c2f34140a73a4c285c30 ]

SSBS provides a relatively cheap mitigation for SSB, but it is still a
mitigation and its presence does not indicate that the CPU is unaffected
by the vulnerability.

Tweak the mitigation logic so that we report the correct string in sysfs.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 arch/arm64/kernel/cpu_errata.c |   10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

--- a/arch/arm64/kernel/cpu_errata.c
+++ b/arch/arm64/kernel/cpu_errata.c
@@ -341,15 +341,17 @@ static bool has_ssbd_mitigation(const st
 
 	WARN_ON(scope != SCOPE_LOCAL_CPU || preemptible());
 
+	/* delay setting __ssb_safe until we get a firmware response */
+	if (is_midr_in_range_list(read_cpuid_id(), entry->midr_range_list))
+		this_cpu_safe = true;
+
 	if (this_cpu_has_cap(ARM64_SSBS)) {
+		if (!this_cpu_safe)
+			__ssb_safe = false;
 		required = false;
 		goto out_printmsg;
 	}
 
-	/* delay setting __ssb_safe until we get a firmware response */
-	if (is_midr_in_range_list(read_cpuid_id(), entry->midr_range_list))
-		this_cpu_safe = true;
-
 	if (psci_ops.smccc_version == SMCCC_VERSION_1_0) {
 		ssbd_state = ARM64_SSBD_UNKNOWN;
 		if (!this_cpu_safe)


Patches currently in stable-queue which might be from ard.biesheuvel@linaro.org are

queue-4.19/arm64-add-sysfs-vulnerability-show-for-meltdown.patch
queue-4.19/arm64-force-ssbs-on-context-switch.patch
queue-4.19/arm64-enable-generic-cpu-vulnerabilites-support.patch
queue-4.19/arm64-provide-a-command-line-to-disable-spectre_v2-mitigation.patch
queue-4.19/arm64-always-enable-spectre-v2-vulnerability-detection.patch
queue-4.19/arm64-docs-document-ssbs-hwcap.patch
queue-4.19/arm64-add-sysfs-vulnerability-show-for-spectre-v1.patch
queue-4.19/arm64-add-sysfs-vulnerability-show-for-speculative-store-bypass.patch
queue-4.19/kvm-arm64-set-sctlr_el2.dssbs-if-ssbd-is-forcefully-disabled-and-vhe.patch
queue-4.19/arm64-always-enable-ssb-vulnerability-detection.patch
queue-4.19/arm64-advertise-mitigation-of-spectre-v2-or-lack-thereof.patch
queue-4.19/arm64-ssbs-don-t-treat-cpus-with-ssbs-as-unaffected-by-ssb.patch
queue-4.19/crypto-skcipher-unmap-pages-after-an-external-error.patch
queue-4.19/arm64-cpufeature-detect-ssbs-and-advertise-to-userspace.patch
queue-4.19/arm64-ssbd-add-support-for-pstate.ssbs-rather-than-trapping-to-el3.patch
queue-4.19/arm64-fix-ssbs-sanitization.patch
queue-4.19/arm64-add-sysfs-vulnerability-show-for-spectre-v2.patch

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