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

Kirill A. Shutemov
2019-07-31T15:09:02Z

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