tee_client_api: register user memory

Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
Signed-off-by: Volodymyr Babchuk <vlad.babchuk@gmail.com>
Reviewed-by: Etienne Carriere <etienne.carriere@linaro.org>
Reviewed-by: Igor Opaniuk <igor.opaniuk@linaro.org>
Reviewed-by: Joakim Bech <joakim.bech@linaro.org>
Reviewed-by: Jens Wiklander <jens.wiklander@linaro.org>

3 files changed, 113 insertions, 27 deletions

diff --git a/libteec/include/linux/tee.h b/libteec/include/linux/tee.h
index 8f6c1a4e..f19b2b4c 100644
--- a/libteec/include/linux/tee.h
+++ b/libteec/include/linux/tee.h
@@ -49,6 +49,7 @@
 #define TEE_MAX_ARG_SIZE        1024
 
 #define TEE_GEN_CAP_GP          (1 << 0)/* GlobalPlatform compliant TEE */
+#define TEE_GEN_CAP_REG_MEM     (1 << 2)/* Supports registering shared memory */
 
 /*
  * TEE Implementation ID
@@ -145,6 +146,36 @@ struct tee_ioctl_shm_register_fd_data {
                                      struct tee_ioctl_shm_register_fd_data)
 
 /**
+ * struct tee_ioctl_shm_register_data - Shared memory register argument
+ * @addr:      [in] Start address of shared memory to register
+ * @length:    [in/out] Length of shared memory to register
+ * @flags:     [in/out] Flags to/from registration.
+ * @id:                [out] Identifier of the shared memory
+ *
+ * The flags field should currently be zero as input. Updated by the call
+ * with actual flags as defined by TEE_IOCTL_SHM_* above.
+ * This structure is used as argument for TEE_IOC_SHM_REGISTER below.
+ */
+struct tee_ioctl_shm_register_data {
+        __u64 addr;
+        __u64 length;
+        __u32 flags;
+        __s32 id;
+};
+
+/**
+ * TEE_IOC_SHM_REGISTER - Register shared memory
+ *
+ * Registers shared memory between the user space process and secure OS.
+ *
+ * Returns a file descriptor on success or < 0 on failure
+ *
+ * The shared memory is unregisterred when the descriptor is closed.
+ */
+#define TEE_IOC_SHM_REGISTER   _IOWR(TEE_IOC_MAGIC, TEE_IOC_BASE + 9, \
+                                     struct tee_ioctl_shm_register_data)
+
+/**
  * struct tee_ioctl_buf_data - Variable sized buffer
  * @buf_ptr:    [in] A __user pointer to a buffer
  * @buf_len:    [in] Length of the buffer above
diff --git a/libteec/src/tee_client_api.c b/libteec/src/tee_client_api.c
index f30dad53..698092b7 100644
--- a/libteec/src/tee_client_api.c
+++ b/libteec/src/tee_client_api.c
@@ -29,8 +29,8 @@
 #include <fcntl.h>
 #include <limits.h>
 #include <pthread.h>
-#include <stdbool.h>
 #include <stdio.h>
+#include <stdlib.h>
 #include <string.h>
 #include <sys/ioctl.h>
 #include <sys/mman.h>
@@ -63,7 +63,8 @@ static void teec_mutex_unlock(pthread_mutex_t *mu)
         pthread_mutex_unlock(mu);
 }
 
-static int teec_open_dev(const char *devname, const char *capabilities)
+static int teec_open_dev(const char *devname, const char *capabilities,
+                         uint32_t *gen_caps)
 {
         struct tee_ioctl_version_data vers;
         int fd;
@@ -93,6 +94,7 @@ static int teec_open_dev(const char *devname, const char *capabilities)
                 }
         }
 
+        *gen_caps = vers.gen_caps;
         return fd;
 err:
         close(fd);
@@ -113,6 +115,21 @@ static int teec_shm_alloc(int fd, size_t size, int *id)
         return shm_fd;
 }
 
+static int teec_shm_register(int fd, void *buf, size_t size, int *id)
+{
+        int shm_fd;
+        struct tee_ioctl_shm_register_data data;
+
+        memset(&data, 0, sizeof(data));
+        data.addr = (uintptr_t)buf;
+        data.length = size;
+        shm_fd = ioctl(fd, TEE_IOC_SHM_REGISTER, &data);
+        if (shm_fd < 0)
+                return -1;
+        *id = data.id;
+        return shm_fd;
+}
+
 TEEC_Result TEEC_InitializeContext(const char *name, TEEC_Context *ctx)
 {
         char devname[PATH_MAX];
@@ -123,10 +140,13 @@ TEEC_Result TEEC_InitializeContext(const char *name, TEEC_Context *ctx)
                 return TEEC_ERROR_BAD_PARAMETERS;
 
         for (n = 0; n < TEEC_MAX_DEV_SEQ; n++) {
+                uint32_t gen_caps;
+
                 snprintf(devname, sizeof(devname), "/dev/tee%zu", n);
-                fd = teec_open_dev(devname, name);
+                fd = teec_open_dev(devname, name, &gen_caps);
                 if (fd >= 0) {
                         ctx->fd = fd;
+                        ctx->reg_mem = gen_caps & TEE_GEN_CAP_REG_MEM;
                         return TEEC_SUCCESS;
                 }
         }
@@ -635,20 +655,29 @@ TEEC_Result TEEC_RegisterSharedMemory(TEEC_Context *ctx, TEEC_SharedMemory *shm)
         s = shm->size;
         if (!s)
                 s = 8;
-
-        fd = teec_shm_alloc(ctx->fd, s, &shm->id);
-        if (fd < 0)
-                return TEEC_ERROR_OUT_OF_MEMORY;
-
-        shm->shadow_buffer = mmap(NULL, s, PROT_READ | PROT_WRITE, MAP_SHARED,
-                                  fd, 0);
-        close(fd);
-        if (shm->shadow_buffer == (void *)MAP_FAILED) {
-                shm->id = -1;
-                return TEEC_ERROR_OUT_OF_MEMORY;
+        if (ctx->reg_mem) {
+                fd = teec_shm_register(ctx->fd, shm->buffer, s, &shm->id);
+                if (fd < 0)
+                        return TEEC_ERROR_OUT_OF_MEMORY;
+                shm->registered_fd = fd;
+                shm->shadow_buffer = NULL;
+        } else {
+                fd = teec_shm_alloc(ctx->fd, s, &shm->id);
+                if (fd < 0)
+                        return TEEC_ERROR_OUT_OF_MEMORY;
+
+                shm->shadow_buffer = mmap(NULL, s, PROT_READ | PROT_WRITE,
+                                          MAP_SHARED, fd, 0);
+                close(fd);
+                if (shm->shadow_buffer == (void *)MAP_FAILED) {
+                        shm->id = -1;
+                        return TEEC_ERROR_OUT_OF_MEMORY;
+                }
+                shm->registered_fd = -1;
         }
+
         shm->alloced_size = s;
-        shm->registered_fd = -1;
+        shm->buffer_allocated = false;
         return TEEC_SUCCESS;
 }
 
@@ -694,19 +723,36 @@ TEEC_Result TEEC_AllocateSharedMemory(TEEC_Context *ctx, TEEC_SharedMemory *shm)
         if (!s)
                 s = 8;
 
-        fd = teec_shm_alloc(ctx->fd, s, &shm->id);
-        if (fd < 0)
-                return TEEC_ERROR_OUT_OF_MEMORY;
+        if (ctx->reg_mem) {
+                shm->buffer = malloc(s);
+                if (!shm->buffer)
+                        return TEEC_ERROR_OUT_OF_MEMORY;
 
-        shm->buffer = mmap(NULL, s, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
-        close(fd);
-        if (shm->buffer == (void *)MAP_FAILED) {
-                shm->id = -1;
-                return TEEC_ERROR_OUT_OF_MEMORY;
+                fd = teec_shm_register(ctx->fd, shm->buffer, s, &shm->id);
+                if (fd < 0) {
+                        free(shm->buffer);
+                        shm->buffer = NULL;
+                        return TEEC_ERROR_OUT_OF_MEMORY;
+                }
+                shm->registered_fd = fd;
+        } else {
+                fd = teec_shm_alloc(ctx->fd, s, &shm->id);
+                if (fd < 0)
+                        return TEEC_ERROR_OUT_OF_MEMORY;
+
+                shm->buffer = mmap(NULL, s, PROT_READ | PROT_WRITE,
+                                   MAP_SHARED, fd, 0);
+                close(fd);
+                if (shm->buffer == (void *)MAP_FAILED) {
+                        shm->id = -1;
+                        return TEEC_ERROR_OUT_OF_MEMORY;
+                }
+                shm->registered_fd = -1;
         }
+
         shm->shadow_buffer = NULL;
         shm->alloced_size = s;
-        shm->registered_fd = -1;
+        shm->buffer_allocated = true;
         return TEEC_SUCCESS;
 }
 
@@ -717,13 +763,19 @@ void TEEC_ReleaseSharedMemory(TEEC_SharedMemory *shm)
 
         if (shm->shadow_buffer)
                 munmap(shm->shadow_buffer, shm->alloced_size);
-        else if (shm->buffer)
-                munmap(shm->buffer, shm->alloced_size);
-        else if (shm->registered_fd >= 0)
+        else if (shm->buffer) {
+                if (shm->registered_fd >= 0) {
+                        if (shm->buffer_allocated)
+                                free(shm->buffer);
+                        close(shm->registered_fd);
+                } else
+                        munmap(shm->buffer, shm->alloced_size);
+        } else if (shm->registered_fd >= 0)
                 close(shm->registered_fd);
 
         shm->id = -1;
         shm->shadow_buffer = NULL;
         shm->buffer = NULL;
         shm->registered_fd = -1;
+        shm->buffer_allocated = false;
 }
diff --git a/public/tee_client_api.h b/public/tee_client_api.h
index a9d8a052..f37886df 100644
--- a/public/tee_client_api.h
+++ b/public/tee_client_api.h
@@ -35,6 +35,7 @@ extern "C" {
 
 #include <stdint.h>
 #include <stddef.h>
+#include <stdbool.h>
 #include <limits.h>
 
 /*
@@ -253,6 +254,7 @@ typedef uint32_t TEEC_Result;
 typedef struct {
         /* Implementation defined */
         int fd;
+        bool reg_mem;
 } TEEC_Context;
 
 /**
@@ -294,6 +296,7 @@ typedef struct {
         size_t alloced_size;
         void *shadow_buffer;
         int registered_fd;
+        bool buffer_allocated;
 } TEEC_SharedMemory;
 
 /**