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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Jeremy Linton <jeremy.linton@arm.com>,
        Andre Przywara <andre.przywara@arm.com>,
        Jonathan Corbet <corbet@lwn.net>,
        Florian Fainelli <f.fainelli@gmail.com>
Subject: [PATCH 4.9 261/271] Documentation: Document arm64 kpti control
Date:   Tue, 28 Jan 2020 15:06:50 +0100
Message-Id: <20200128135912.026352539@linuxfoundation.org>
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From: Jeremy Linton <jeremy.linton@arm.com>

commit de19055564c8f8f9d366f8db3395836da0b2176c upstream.

For a while Arm64 has been capable of force enabling
or disabling the kpti mitigations. Lets make sure the
documentation reflects that.

Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
[florian: patch the correct file]
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 Documentation/kernel-parameters.txt |    6 ++++++
 1 file changed, 6 insertions(+)

--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -1965,6 +1965,12 @@ bytes respectively. Such letter suffixes
 			kmemcheck=2 (one-shot mode)
 			Default: 2 (one-shot mode)
 
+	kpti=		[ARM64] Control page table isolation of user
+			and kernel address spaces.
+			Default: enabled on cores which need mitigation.
+			0: force disabled
+			1: force enabled
+
 	kstack=N	[X86] Print N words from the kernel stack
 			in oops dumps.