[PATCHv2 42/59] syscall/x86: Wire up a system call for MKTME encryption keys

From: "Kirill A. Shutemov" <kirill@shutemov.name>
To: Andrew Morton <akpm@linux-foundation.org>,
	x86@kernel.org, Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>, "H. Peter Anvin" <hpa@zytor.com>,
	Borislav Petkov <bp@alien8.de>,
	Peter Zijlstra <peterz@infradead.org>,
	Andy Lutomirski <luto@amacapital.net>,
	David Howells <dhowells@redhat.com>
Cc: Kees Cook <keescook@chromium.org>,
	Dave Hansen <dave.hansen@intel.com>,
	Kai Huang <kai.huang@linux.intel.com>,
	Jacob Pan <jacob.jun.pan@linux.intel.com>,
	Alison Schofield <alison.schofield@intel.com>,
	linux-mm@kvack.org, kvm@vger.kernel.org,
	keyrings@vger.kernel.org, linux-kernel@vger.kernel.org,
	"Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>
Subject: [PATCHv2 42/59] syscall/x86: Wire up a system call for MKTME encryption keys
Date: Wed, 31 Jul 2019 18:07:56 +0300	[thread overview]
Message-ID: <20190731150813.26289-43-kirill.shutemov@linux.intel.com> (raw)
In-Reply-To: <20190731150813.26289-1-kirill.shutemov@linux.intel.com>

From: Alison Schofield <alison.schofield@intel.com>

encrypt_mprotect() is a new system call to support memory encryption.

It takes the same parameters as legacy mprotect, plus an additional
key serial number that is mapped to an encryption keyid.

Signed-off-by: Alison Schofield <alison.schofield@intel.com>
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
---
 arch/x86/entry/syscalls/syscall_32.tbl | 1 +
 arch/x86/entry/syscalls/syscall_64.tbl | 1 +
 include/linux/syscalls.h               | 2 ++
 include/uapi/asm-generic/unistd.h      | 4 +++-
 kernel/sys_ni.c                        | 2 ++
 5 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/arch/x86/entry/syscalls/syscall_32.tbl b/arch/x86/entry/syscalls/syscall_32.tbl
index c00019abd076..1b30cd007a6a 100644
--- a/arch/x86/entry/syscalls/syscall_32.tbl
+++ b/arch/x86/entry/syscalls/syscall_32.tbl
@@ -440,3 +440,4 @@
 433	i386	fspick			sys_fspick			__ia32_sys_fspick
 434	i386	pidfd_open		sys_pidfd_open			__ia32_sys_pidfd_open
 435	i386	clone3			sys_clone3			__ia32_sys_clone3
+436	i386	encrypt_mprotect	sys_encrypt_mprotect		__ia32_sys_encrypt_mprotect
diff --git a/arch/x86/entry/syscalls/syscall_64.tbl b/arch/x86/entry/syscalls/syscall_64.tbl
index c29976eca4a8..716d8a89159b 100644
--- a/arch/x86/entry/syscalls/syscall_64.tbl
+++ b/arch/x86/entry/syscalls/syscall_64.tbl
@@ -357,6 +357,7 @@
 433	common	fspick			__x64_sys_fspick
 434	common	pidfd_open		__x64_sys_pidfd_open
 435	common	clone3			__x64_sys_clone3/ptregs
+436	common	encrypt_mprotect	__x64_sys_encrypt_mprotect
 
 #
 # x32-specific system call numbers start at 512 to avoid cache impact
diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index 88145da7d140..4494b1d9c85a 100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -1000,6 +1000,8 @@ asmlinkage long sys_fspick(int dfd, const char __user *path, unsigned int flags)
 asmlinkage long sys_pidfd_send_signal(int pidfd, int sig,
 				       siginfo_t __user *info,
 				       unsigned int flags);
+asmlinkage long sys_encrypt_mprotect(unsigned long start, size_t len,
+				     unsigned long prot, key_serial_t serial);
 
 /*
  * Architecture-specific system calls
diff --git a/include/uapi/asm-generic/unistd.h b/include/uapi/asm-generic/unistd.h
index 1be0e798e362..7c1cd13f6aaf 100644
--- a/include/uapi/asm-generic/unistd.h
+++ b/include/uapi/asm-generic/unistd.h
@@ -850,9 +850,11 @@ __SYSCALL(__NR_pidfd_open, sys_pidfd_open)
 #define __NR_clone3 435
 __SYSCALL(__NR_clone3, sys_clone3)
 #endif
+#define __NR_encrypt_mprotect 436
+__SYSCALL(__NR_encrypt_mprotect, sys_encrypt_mprotect)
 
 #undef __NR_syscalls
-#define __NR_syscalls 436
+#define __NR_syscalls 437
 
 /*
  * 32 bit systems traditionally used different
diff --git a/kernel/sys_ni.c b/kernel/sys_ni.c
index 34b76895b81e..84c8c47cf9d6 100644
--- a/kernel/sys_ni.c
+++ b/kernel/sys_ni.c
@@ -349,6 +349,8 @@ COND_SYSCALL(pkey_mprotect);
 COND_SYSCALL(pkey_alloc);
 COND_SYSCALL(pkey_free);
 
+/* multi-key total memory encryption keys */
+COND_SYSCALL(encrypt_mprotect);
 
 /*
  * Architecture specific weak syscall entries.
-- 
2.21.0

