linux-kernel - [PATCH v3 09/15] x86/cpu: Add a configuration and command line option for Key Locker

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20211124200700.15888-10-chang.seok.bae@intel.com>
Date:   Wed, 24 Nov 2021 12:06:54 -0800
From:   "Chang S. Bae" <chang.seok.bae@...el.com>
To:     tglx@...utronix.de, bp@...e.de, dave.hansen@...ux.intel.com,
        mingo@...nel.org, luto@...nel.org, x86@...nel.org,
        herbert@...dor.apana.org.au
Cc:     linux-kernel@...r.kernel.org, linux-crypto@...r.kernel.org,
        dan.j.williams@...el.com, charishma1.gairuboyina@...el.com,
        kumar.n.dwarakanath@...el.com, lalithambika.krishnakumar@...el.com,
        ravi.v.shankar@...el.com, chang.seok.bae@...el.com,
        linux-doc@...r.kernel.org
Subject: [PATCH v3 09/15] x86/cpu: Add a configuration and command line option for Key Locker

Add CONFIG_X86_KEYLOCKER to gate whether Key Locker is initialized at boot.
The option is selected by the Key Locker cipher module CRYPTO_AES_KL (to be
added in a later patch).

Add a new command line option "nokeylocker" to optionally override the
default CONFIG_X86_KEYLOCKER=y behavior.

Signed-off-by: Chang S. Bae <chang.seok.bae@...el.com>
Reviewed-by: Dan Williams <dan.j.williams@...el.com>
Cc: linux-doc@...r.kernel.org
Cc: linux-kernel@...r.kernel.org
---
Changes from RFC v2:
* Make the option selected by CRYPTO_AES_KL. (Dan Williams)
* Massage the changelog and the config option description.
---
 Documentation/admin-guide/kernel-parameters.txt |  2 ++
 arch/x86/Kconfig                                |  3 +++
 arch/x86/kernel/cpu/common.c                    | 16 ++++++++++++++++
 3 files changed, 21 insertions(+)

diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 9725c546a0d4..336495722b12 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -3399,6 +3399,8 @@
 
 	nohugevmalloc	[PPC] Disable kernel huge vmalloc mappings.
 
+	nokeylocker	[X86] Disable Key Locker hardware feature.
+
 	nosmt		[KNL,S390] Disable symmetric multithreading (SMT).
 			Equivalent to smt=1.
 
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index b9281fab4e3e..b0050e8cf723 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -1864,6 +1864,9 @@ config X86_INTEL_MEMORY_PROTECTION_KEYS
 
 	  If unsure, say y.
 
+config X86_KEYLOCKER
+	bool
+
 choice
 	prompt "TSX enable mode"
 	depends on CPU_SUP_INTEL
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 23b4aa437c1e..db1fc9ff0fe3 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -364,6 +364,22 @@ static __always_inline void setup_umip(struct cpuinfo_x86 *c)
 /* These bits should not change their value after CPU init is finished. */
 static const unsigned long cr4_pinned_mask =
 	X86_CR4_SMEP | X86_CR4_SMAP | X86_CR4_UMIP | X86_CR4_FSGSBASE;
+
+static __init int x86_nokeylocker_setup(char *arg)
+{
+	/* Expect an exact match without trailing characters. */
+	if (strlen(arg))
+		return 0;
+
+	if (!cpu_feature_enabled(X86_FEATURE_KEYLOCKER))
+		return 1;
+
+	setup_clear_cpu_cap(X86_FEATURE_KEYLOCKER);
+	pr_info("x86/keylocker: Disabled by kernel command line.\n");
+	return 1;
+}
+__setup("nokeylocker", x86_nokeylocker_setup);
+
 static DEFINE_STATIC_KEY_FALSE_RO(cr_pinning);
 static unsigned long cr4_pinned_bits __ro_after_init;
 
-- 
2.17.1