From: Alison Schofield <alison.schofield@xxxxxxxxx>
Signed-off-by: Alison Schofield <alison.schofield@xxxxxxxxx>
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
---
Documentation/x86/mktme/index.rst | 1 +
Documentation/x86/mktme/mktme_demo.rst | 53 ++++++++++++++++++++++++++
2 files changed, 54 insertions(+)
create mode 100644 Documentation/x86/mktme/mktme_demo.rst
diff --git a/Documentation/x86/mktme/index.rst b/Documentation/x86/mktme/index.rst
index ca3c76adc596..3af322d13225 100644
--- a/Documentation/x86/mktme/index.rst
+++ b/Documentation/x86/mktme/index.rst
@@ -10,3 +10,4 @@ Multi-Key Total Memory Encryption (MKTME)
mktme_configuration
mktme_keys
mktme_encrypt
+ mktme_demo
diff --git a/Documentation/x86/mktme/mktme_demo.rst b/Documentation/x86/mktme/mktme_demo.rst
new file mode 100644
index 000000000000..5af78617f887
--- /dev/null
+++ b/Documentation/x86/mktme/mktme_demo.rst
@@ -0,0 +1,53 @@
+Demonstration Program using MKTME API's
+=======================================
+
+/* Compile with the keyutils library: cc -o mdemo mdemo.c -lkeyutils */
+
+#include <sys/mman.h>
+#include <sys/syscall.h>
+#include <sys/types.h>
+#include <keyutils.h>
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+
+#define PAGE_SIZE sysconf(_SC_PAGE_SIZE)
+#define sys_encrypt_mprotect 434
+
+void main(void)
+{
+ char *options_CPU = "algorithm=aes-xts-128 type=cpu";
+ long size = PAGE_SIZE;
+ key_serial_t key;
+ void *ptra;
+ int ret;
+
+ /* Allocate an MKTME Key */
+ key = add_key("mktme", "testkey", options_CPU, strlen(options_CPU),
+ KEY_SPEC_THREAD_KEYRING);
+
+ if (key == -1) {
+ printf("addkey FAILED\n");
+ return;
+ }
+ /* Map a page of ANONYMOUS memory */
+ ptra = mmap(NULL, size, PROT_NONE, MAP_ANONYMOUS|MAP_PRIVATE, -1, 0);
+ if (!ptra) {
+ printf("failed to mmap");
+ goto inval_key;
+ }
+ /* Encrypt that page of memory with the MKTME Key */
+ ret = syscall(sys_encrypt_mprotect, ptra, size, PROT_NONE, key);
+ if (ret)
+ printf("mprotect error [%d]\n", ret);
+
+ /* Enjoy that page of encrypted memory */
+
+ /* Free the memory */
+ ret = munmap(ptra, size);
+
+inval_key:
+ /* Free the Key */
+ if (keyctl(KEYCTL_INVALIDATE, key) == -1)
+ printf("invalidate failed on key [%d]\n", key);
+}
--
2.21.0
