[RFC v4 03/17] x86: key creation with PKEY_DISABLE_EXECUTE disallowed

From: Ram Pai <linuxram@us.ibm.com>
To: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org,
	linux-arch@vger.kernel.org, linux-mm@kvack.org, x86@kernel.org,
	linux-doc@vger.kernel.org, linux-kselftest@vger.kernel.org
Cc: benh@kernel.crashing.org, paulus@samba.org, mpe@ellerman.id.au,
	khandual@linux.vnet.ibm.com, aneesh.kumar@linux.vnet.ibm.com,
	bsingharora@gmail.com, dave.hansen@intel.com, hbabu@us.ibm.com,
	linuxram@us.ibm.com, arnd@arndb.de, akpm@linux-foundation.org,
	corbet@lwn.net, mingo@redhat.com
Subject: [RFC v4 03/17] x86: key creation with PKEY_DISABLE_EXECUTE disallowed
Date: Tue, 27 Jun 2017 03:11:45 -0700	[thread overview]
Message-ID: <1498558319-32466-4-git-send-email-linuxram@us.ibm.com> (raw)
In-Reply-To: <1498558319-32466-1-git-send-email-linuxram@us.ibm.com>

x86 does not support disabling execute permissions on a pkey.

Signed-off-by: Ram Pai <linuxram@us.ibm.com>
---
 arch/x86/kernel/fpu/xstate.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c
index c24ac1e..d582631 100644
--- a/arch/x86/kernel/fpu/xstate.c
+++ b/arch/x86/kernel/fpu/xstate.c
@@ -900,6 +900,9 @@ int arch_set_user_pkey_access(struct task_struct *tsk, int pkey,
 	if (!boot_cpu_has(X86_FEATURE_OSPKE))
 		return -EINVAL;
 
+	if (init_val & PKEY_DISABLE_EXECUTE)
+		return -EINVAL;
+
 	/* Set the bits we need in PKRU:  */
 	if (init_val & PKEY_DISABLE_ACCESS)
 		new_pkru_bits |= PKRU_AD_BIT;
-- 
1.8.3.1

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