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From:   Randy Dunlap <rdunlap@infradead.org>
To:     linux-kernel@vger.kernel.org
Cc:     Randy Dunlap <rdunlap@infradead.org>,
        Dexuan Cui <decui@microsoft.com>, linux-crypto@vger.kernel.org,
        Eric Biggers <ebiggers@kernel.org>,
        Herbert Xu <herbert@gondor.apana.org.au>,
        "David S. Miller" <davem@davemloft.net>,
        Jonathan Corbet <corbet@lwn.net>, linux-doc@vger.kernel.org
Subject: [PATCH v2] Documentation: crypto: add info about "fips=" boot option
Date:   Mon, 29 Mar 2021 22:06:51 -0700
Message-Id: <20210330050651.13344-1-rdunlap@infradead.org>
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Having just seen a report of using "fips=1" on the kernel command line,
I could not find it documented anywhere, so add some help for it.

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Dexuan Cui <decui@microsoft.com>
Cc: linux-crypto@vger.kernel.org
Cc: Eric Biggers <ebiggers@kernel.org>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: linux-doc@vger.kernel.org
---
Updates/corrections welcome.

v2: drop comment that "fips_enabled can cause some tests to be skipped".

 Documentation/admin-guide/kernel-parameters.txt |   14 ++++++++++++++
 1 file changed, 14 insertions(+)

--- linux-next-20210329.orig/Documentation/admin-guide/kernel-parameters.txt
+++ linux-next-20210329/Documentation/admin-guide/kernel-parameters.txt
@@ -1370,6 +1370,20 @@
 			See Documentation/admin-guide/sysctl/net.rst for
 			fb_tunnels_only_for_init_ns
 
+	fips=		Format: { 0 | 1}
+			Use to disable (0) or enable (1) FIPS mode.
+			If enabled, any process that is waiting on the
+			'fips_fail_notif_chain' will be notified of fips
+			failures.
+			This setting can also be modified via sysctl at
+			/proc/sysctl/crypto/fips_enabled, i.e.,
+			crypto.fips_enabled.
+			If fips_enabled = 1 and a test fails, it will cause a
+			kernel panic.
+			If fips_enabled = 1, RSA test requires a key size of
+			2K or larger.
+			It can also effect which ECC curve is used.
+
 	floppy=		[HW]
 			See Documentation/admin-guide/blockdev/floppy.rst.