linux/drivers/tee/tee_core.c
Etienne Carriere ab9d3db5b3 tee: check shm references are consistent in offset/size
This change prevents userland from referencing TEE shared memory
outside the area initially allocated by its owner. Prior this change an
application could not reference or access memory it did not own but
it could reference memory not explicitly allocated by owner but still
allocated to the owner due to the memory allocation granule.

Reported-by: Alexandre Jutras <alexandre.jutras@nxp.com>
Signed-off-by: Etienne Carriere <etienne.carriere@linaro.org>
Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
2018-05-07 11:51:03 +02:00

965 lines
23 KiB
C

/*
* Copyright (c) 2015-2016, Linaro Limited
*
* This software is licensed under the terms of the GNU General Public
* License version 2, as published by the Free Software Foundation, and
* may be copied, distributed, and modified under those terms.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
*/
#define pr_fmt(fmt) "%s: " fmt, __func__
#include <linux/cdev.h>
#include <linux/device.h>
#include <linux/fs.h>
#include <linux/idr.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/tee_drv.h>
#include <linux/uaccess.h>
#include "tee_private.h"
#define TEE_NUM_DEVICES 32
#define TEE_IOCTL_PARAM_SIZE(x) (sizeof(struct tee_param) * (x))
/*
* Unprivileged devices in the lower half range and privileged devices in
* the upper half range.
*/
static DECLARE_BITMAP(dev_mask, TEE_NUM_DEVICES);
static DEFINE_SPINLOCK(driver_lock);
static struct class *tee_class;
static dev_t tee_devt;
static int tee_open(struct inode *inode, struct file *filp)
{
int rc;
struct tee_device *teedev;
struct tee_context *ctx;
teedev = container_of(inode->i_cdev, struct tee_device, cdev);
if (!tee_device_get(teedev))
return -EINVAL;
ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
if (!ctx) {
rc = -ENOMEM;
goto err;
}
kref_init(&ctx->refcount);
ctx->teedev = teedev;
INIT_LIST_HEAD(&ctx->list_shm);
filp->private_data = ctx;
rc = teedev->desc->ops->open(ctx);
if (rc)
goto err;
return 0;
err:
kfree(ctx);
tee_device_put(teedev);
return rc;
}
void teedev_ctx_get(struct tee_context *ctx)
{
if (ctx->releasing)
return;
kref_get(&ctx->refcount);
}
static void teedev_ctx_release(struct kref *ref)
{
struct tee_context *ctx = container_of(ref, struct tee_context,
refcount);
ctx->releasing = true;
ctx->teedev->desc->ops->release(ctx);
kfree(ctx);
}
void teedev_ctx_put(struct tee_context *ctx)
{
if (ctx->releasing)
return;
kref_put(&ctx->refcount, teedev_ctx_release);
}
static void teedev_close_context(struct tee_context *ctx)
{
tee_device_put(ctx->teedev);
teedev_ctx_put(ctx);
}
static int tee_release(struct inode *inode, struct file *filp)
{
teedev_close_context(filp->private_data);
return 0;
}
static int tee_ioctl_version(struct tee_context *ctx,
struct tee_ioctl_version_data __user *uvers)
{
struct tee_ioctl_version_data vers;
ctx->teedev->desc->ops->get_version(ctx->teedev, &vers);
if (ctx->teedev->desc->flags & TEE_DESC_PRIVILEGED)
vers.gen_caps |= TEE_GEN_CAP_PRIVILEGED;
if (copy_to_user(uvers, &vers, sizeof(vers)))
return -EFAULT;
return 0;
}
static int tee_ioctl_shm_alloc(struct tee_context *ctx,
struct tee_ioctl_shm_alloc_data __user *udata)
{
long ret;
struct tee_ioctl_shm_alloc_data data;
struct tee_shm *shm;
if (copy_from_user(&data, udata, sizeof(data)))
return -EFAULT;
/* Currently no input flags are supported */
if (data.flags)
return -EINVAL;
shm = tee_shm_alloc(ctx, data.size, TEE_SHM_MAPPED | TEE_SHM_DMA_BUF);
if (IS_ERR(shm))
return PTR_ERR(shm);
data.id = shm->id;
data.flags = shm->flags;
data.size = shm->size;
if (copy_to_user(udata, &data, sizeof(data)))
ret = -EFAULT;
else
ret = tee_shm_get_fd(shm);
/*
* When user space closes the file descriptor the shared memory
* should be freed or if tee_shm_get_fd() failed then it will
* be freed immediately.
*/
tee_shm_put(shm);
return ret;
}
static int
tee_ioctl_shm_register(struct tee_context *ctx,
struct tee_ioctl_shm_register_data __user *udata)
{
long ret;
struct tee_ioctl_shm_register_data data;
struct tee_shm *shm;
if (copy_from_user(&data, udata, sizeof(data)))
return -EFAULT;
/* Currently no input flags are supported */
if (data.flags)
return -EINVAL;
shm = tee_shm_register(ctx, data.addr, data.length,
TEE_SHM_DMA_BUF | TEE_SHM_USER_MAPPED);
if (IS_ERR(shm))
return PTR_ERR(shm);
data.id = shm->id;
data.flags = shm->flags;
data.length = shm->size;
if (copy_to_user(udata, &data, sizeof(data)))
ret = -EFAULT;
else
ret = tee_shm_get_fd(shm);
/*
* When user space closes the file descriptor the shared memory
* should be freed or if tee_shm_get_fd() failed then it will
* be freed immediately.
*/
tee_shm_put(shm);
return ret;
}
static int params_from_user(struct tee_context *ctx, struct tee_param *params,
size_t num_params,
struct tee_ioctl_param __user *uparams)
{
size_t n;
for (n = 0; n < num_params; n++) {
struct tee_shm *shm;
struct tee_ioctl_param ip;
if (copy_from_user(&ip, uparams + n, sizeof(ip)))
return -EFAULT;
/* All unused attribute bits has to be zero */
if (ip.attr & ~TEE_IOCTL_PARAM_ATTR_MASK)
return -EINVAL;
params[n].attr = ip.attr;
switch (ip.attr & TEE_IOCTL_PARAM_ATTR_TYPE_MASK) {
case TEE_IOCTL_PARAM_ATTR_TYPE_NONE:
case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_OUTPUT:
break;
case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INPUT:
case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INOUT:
params[n].u.value.a = ip.a;
params[n].u.value.b = ip.b;
params[n].u.value.c = ip.c;
break;
case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT:
case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT:
case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INOUT:
/*
* If we fail to get a pointer to a shared memory
* object (and increase the ref count) from an
* identifier we return an error. All pointers that
* has been added in params have an increased ref
* count. It's the callers responibility to do
* tee_shm_put() on all resolved pointers.
*/
shm = tee_shm_get_from_id(ctx, ip.c);
if (IS_ERR(shm))
return PTR_ERR(shm);
/*
* Ensure offset + size does not overflow offset
* and does not overflow the size of the referred
* shared memory object.
*/
if ((ip.a + ip.b) < ip.a ||
(ip.a + ip.b) > shm->size) {
tee_shm_put(shm);
return -EINVAL;
}
params[n].u.memref.shm_offs = ip.a;
params[n].u.memref.size = ip.b;
params[n].u.memref.shm = shm;
break;
default:
/* Unknown attribute */
return -EINVAL;
}
}
return 0;
}
static int params_to_user(struct tee_ioctl_param __user *uparams,
size_t num_params, struct tee_param *params)
{
size_t n;
for (n = 0; n < num_params; n++) {
struct tee_ioctl_param __user *up = uparams + n;
struct tee_param *p = params + n;
switch (p->attr) {
case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_OUTPUT:
case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INOUT:
if (put_user(p->u.value.a, &up->a) ||
put_user(p->u.value.b, &up->b) ||
put_user(p->u.value.c, &up->c))
return -EFAULT;
break;
case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT:
case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INOUT:
if (put_user((u64)p->u.memref.size, &up->b))
return -EFAULT;
default:
break;
}
}
return 0;
}
static int tee_ioctl_open_session(struct tee_context *ctx,
struct tee_ioctl_buf_data __user *ubuf)
{
int rc;
size_t n;
struct tee_ioctl_buf_data buf;
struct tee_ioctl_open_session_arg __user *uarg;
struct tee_ioctl_open_session_arg arg;
struct tee_ioctl_param __user *uparams = NULL;
struct tee_param *params = NULL;
bool have_session = false;
if (!ctx->teedev->desc->ops->open_session)
return -EINVAL;
if (copy_from_user(&buf, ubuf, sizeof(buf)))
return -EFAULT;
if (buf.buf_len > TEE_MAX_ARG_SIZE ||
buf.buf_len < sizeof(struct tee_ioctl_open_session_arg))
return -EINVAL;
uarg = u64_to_user_ptr(buf.buf_ptr);
if (copy_from_user(&arg, uarg, sizeof(arg)))
return -EFAULT;
if (sizeof(arg) + TEE_IOCTL_PARAM_SIZE(arg.num_params) != buf.buf_len)
return -EINVAL;
if (arg.num_params) {
params = kcalloc(arg.num_params, sizeof(struct tee_param),
GFP_KERNEL);
if (!params)
return -ENOMEM;
uparams = uarg->params;
rc = params_from_user(ctx, params, arg.num_params, uparams);
if (rc)
goto out;
}
rc = ctx->teedev->desc->ops->open_session(ctx, &arg, params);
if (rc)
goto out;
have_session = true;
if (put_user(arg.session, &uarg->session) ||
put_user(arg.ret, &uarg->ret) ||
put_user(arg.ret_origin, &uarg->ret_origin)) {
rc = -EFAULT;
goto out;
}
rc = params_to_user(uparams, arg.num_params, params);
out:
/*
* If we've succeeded to open the session but failed to communicate
* it back to user space, close the session again to avoid leakage.
*/
if (rc && have_session && ctx->teedev->desc->ops->close_session)
ctx->teedev->desc->ops->close_session(ctx, arg.session);
if (params) {
/* Decrease ref count for all valid shared memory pointers */
for (n = 0; n < arg.num_params; n++)
if (tee_param_is_memref(params + n) &&
params[n].u.memref.shm)
tee_shm_put(params[n].u.memref.shm);
kfree(params);
}
return rc;
}
static int tee_ioctl_invoke(struct tee_context *ctx,
struct tee_ioctl_buf_data __user *ubuf)
{
int rc;
size_t n;
struct tee_ioctl_buf_data buf;
struct tee_ioctl_invoke_arg __user *uarg;
struct tee_ioctl_invoke_arg arg;
struct tee_ioctl_param __user *uparams = NULL;
struct tee_param *params = NULL;
if (!ctx->teedev->desc->ops->invoke_func)
return -EINVAL;
if (copy_from_user(&buf, ubuf, sizeof(buf)))
return -EFAULT;
if (buf.buf_len > TEE_MAX_ARG_SIZE ||
buf.buf_len < sizeof(struct tee_ioctl_invoke_arg))
return -EINVAL;
uarg = u64_to_user_ptr(buf.buf_ptr);
if (copy_from_user(&arg, uarg, sizeof(arg)))
return -EFAULT;
if (sizeof(arg) + TEE_IOCTL_PARAM_SIZE(arg.num_params) != buf.buf_len)
return -EINVAL;
if (arg.num_params) {
params = kcalloc(arg.num_params, sizeof(struct tee_param),
GFP_KERNEL);
if (!params)
return -ENOMEM;
uparams = uarg->params;
rc = params_from_user(ctx, params, arg.num_params, uparams);
if (rc)
goto out;
}
rc = ctx->teedev->desc->ops->invoke_func(ctx, &arg, params);
if (rc)
goto out;
if (put_user(arg.ret, &uarg->ret) ||
put_user(arg.ret_origin, &uarg->ret_origin)) {
rc = -EFAULT;
goto out;
}
rc = params_to_user(uparams, arg.num_params, params);
out:
if (params) {
/* Decrease ref count for all valid shared memory pointers */
for (n = 0; n < arg.num_params; n++)
if (tee_param_is_memref(params + n) &&
params[n].u.memref.shm)
tee_shm_put(params[n].u.memref.shm);
kfree(params);
}
return rc;
}
static int tee_ioctl_cancel(struct tee_context *ctx,
struct tee_ioctl_cancel_arg __user *uarg)
{
struct tee_ioctl_cancel_arg arg;
if (!ctx->teedev->desc->ops->cancel_req)
return -EINVAL;
if (copy_from_user(&arg, uarg, sizeof(arg)))
return -EFAULT;
return ctx->teedev->desc->ops->cancel_req(ctx, arg.cancel_id,
arg.session);
}
static int
tee_ioctl_close_session(struct tee_context *ctx,
struct tee_ioctl_close_session_arg __user *uarg)
{
struct tee_ioctl_close_session_arg arg;
if (!ctx->teedev->desc->ops->close_session)
return -EINVAL;
if (copy_from_user(&arg, uarg, sizeof(arg)))
return -EFAULT;
return ctx->teedev->desc->ops->close_session(ctx, arg.session);
}
static int params_to_supp(struct tee_context *ctx,
struct tee_ioctl_param __user *uparams,
size_t num_params, struct tee_param *params)
{
size_t n;
for (n = 0; n < num_params; n++) {
struct tee_ioctl_param ip;
struct tee_param *p = params + n;
ip.attr = p->attr;
switch (p->attr & TEE_IOCTL_PARAM_ATTR_TYPE_MASK) {
case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INPUT:
case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INOUT:
ip.a = p->u.value.a;
ip.b = p->u.value.b;
ip.c = p->u.value.c;
break;
case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT:
case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT:
case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INOUT:
ip.b = p->u.memref.size;
if (!p->u.memref.shm) {
ip.a = 0;
ip.c = (u64)-1; /* invalid shm id */
break;
}
ip.a = p->u.memref.shm_offs;
ip.c = p->u.memref.shm->id;
break;
default:
ip.a = 0;
ip.b = 0;
ip.c = 0;
break;
}
if (copy_to_user(uparams + n, &ip, sizeof(ip)))
return -EFAULT;
}
return 0;
}
static int tee_ioctl_supp_recv(struct tee_context *ctx,
struct tee_ioctl_buf_data __user *ubuf)
{
int rc;
struct tee_ioctl_buf_data buf;
struct tee_iocl_supp_recv_arg __user *uarg;
struct tee_param *params;
u32 num_params;
u32 func;
if (!ctx->teedev->desc->ops->supp_recv)
return -EINVAL;
if (copy_from_user(&buf, ubuf, sizeof(buf)))
return -EFAULT;
if (buf.buf_len > TEE_MAX_ARG_SIZE ||
buf.buf_len < sizeof(struct tee_iocl_supp_recv_arg))
return -EINVAL;
uarg = u64_to_user_ptr(buf.buf_ptr);
if (get_user(num_params, &uarg->num_params))
return -EFAULT;
if (sizeof(*uarg) + TEE_IOCTL_PARAM_SIZE(num_params) != buf.buf_len)
return -EINVAL;
params = kcalloc(num_params, sizeof(struct tee_param), GFP_KERNEL);
if (!params)
return -ENOMEM;
rc = params_from_user(ctx, params, num_params, uarg->params);
if (rc)
goto out;
rc = ctx->teedev->desc->ops->supp_recv(ctx, &func, &num_params, params);
if (rc)
goto out;
if (put_user(func, &uarg->func) ||
put_user(num_params, &uarg->num_params)) {
rc = -EFAULT;
goto out;
}
rc = params_to_supp(ctx, uarg->params, num_params, params);
out:
kfree(params);
return rc;
}
static int params_from_supp(struct tee_param *params, size_t num_params,
struct tee_ioctl_param __user *uparams)
{
size_t n;
for (n = 0; n < num_params; n++) {
struct tee_param *p = params + n;
struct tee_ioctl_param ip;
if (copy_from_user(&ip, uparams + n, sizeof(ip)))
return -EFAULT;
/* All unused attribute bits has to be zero */
if (ip.attr & ~TEE_IOCTL_PARAM_ATTR_MASK)
return -EINVAL;
p->attr = ip.attr;
switch (ip.attr & TEE_IOCTL_PARAM_ATTR_TYPE_MASK) {
case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_OUTPUT:
case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INOUT:
/* Only out and in/out values can be updated */
p->u.value.a = ip.a;
p->u.value.b = ip.b;
p->u.value.c = ip.c;
break;
case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT:
case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INOUT:
/*
* Only the size of the memref can be updated.
* Since we don't have access to the original
* parameters here, only store the supplied size.
* The driver will copy the updated size into the
* original parameters.
*/
p->u.memref.shm = NULL;
p->u.memref.shm_offs = 0;
p->u.memref.size = ip.b;
break;
default:
memset(&p->u, 0, sizeof(p->u));
break;
}
}
return 0;
}
static int tee_ioctl_supp_send(struct tee_context *ctx,
struct tee_ioctl_buf_data __user *ubuf)
{
long rc;
struct tee_ioctl_buf_data buf;
struct tee_iocl_supp_send_arg __user *uarg;
struct tee_param *params;
u32 num_params;
u32 ret;
/* Not valid for this driver */
if (!ctx->teedev->desc->ops->supp_send)
return -EINVAL;
if (copy_from_user(&buf, ubuf, sizeof(buf)))
return -EFAULT;
if (buf.buf_len > TEE_MAX_ARG_SIZE ||
buf.buf_len < sizeof(struct tee_iocl_supp_send_arg))
return -EINVAL;
uarg = u64_to_user_ptr(buf.buf_ptr);
if (get_user(ret, &uarg->ret) ||
get_user(num_params, &uarg->num_params))
return -EFAULT;
if (sizeof(*uarg) + TEE_IOCTL_PARAM_SIZE(num_params) > buf.buf_len)
return -EINVAL;
params = kcalloc(num_params, sizeof(struct tee_param), GFP_KERNEL);
if (!params)
return -ENOMEM;
rc = params_from_supp(params, num_params, uarg->params);
if (rc)
goto out;
rc = ctx->teedev->desc->ops->supp_send(ctx, ret, num_params, params);
out:
kfree(params);
return rc;
}
static long tee_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
{
struct tee_context *ctx = filp->private_data;
void __user *uarg = (void __user *)arg;
switch (cmd) {
case TEE_IOC_VERSION:
return tee_ioctl_version(ctx, uarg);
case TEE_IOC_SHM_ALLOC:
return tee_ioctl_shm_alloc(ctx, uarg);
case TEE_IOC_SHM_REGISTER:
return tee_ioctl_shm_register(ctx, uarg);
case TEE_IOC_OPEN_SESSION:
return tee_ioctl_open_session(ctx, uarg);
case TEE_IOC_INVOKE:
return tee_ioctl_invoke(ctx, uarg);
case TEE_IOC_CANCEL:
return tee_ioctl_cancel(ctx, uarg);
case TEE_IOC_CLOSE_SESSION:
return tee_ioctl_close_session(ctx, uarg);
case TEE_IOC_SUPPL_RECV:
return tee_ioctl_supp_recv(ctx, uarg);
case TEE_IOC_SUPPL_SEND:
return tee_ioctl_supp_send(ctx, uarg);
default:
return -EINVAL;
}
}
static const struct file_operations tee_fops = {
.owner = THIS_MODULE,
.open = tee_open,
.release = tee_release,
.unlocked_ioctl = tee_ioctl,
.compat_ioctl = tee_ioctl,
};
static void tee_release_device(struct device *dev)
{
struct tee_device *teedev = container_of(dev, struct tee_device, dev);
spin_lock(&driver_lock);
clear_bit(teedev->id, dev_mask);
spin_unlock(&driver_lock);
mutex_destroy(&teedev->mutex);
idr_destroy(&teedev->idr);
kfree(teedev);
}
/**
* tee_device_alloc() - Allocate a new struct tee_device instance
* @teedesc: Descriptor for this driver
* @dev: Parent device for this device
* @pool: Shared memory pool, NULL if not used
* @driver_data: Private driver data for this device
*
* Allocates a new struct tee_device instance. The device is
* removed by tee_device_unregister().
*
* @returns a pointer to a 'struct tee_device' or an ERR_PTR on failure
*/
struct tee_device *tee_device_alloc(const struct tee_desc *teedesc,
struct device *dev,
struct tee_shm_pool *pool,
void *driver_data)
{
struct tee_device *teedev;
void *ret;
int rc, max_id;
int offs = 0;
if (!teedesc || !teedesc->name || !teedesc->ops ||
!teedesc->ops->get_version || !teedesc->ops->open ||
!teedesc->ops->release || !pool)
return ERR_PTR(-EINVAL);
teedev = kzalloc(sizeof(*teedev), GFP_KERNEL);
if (!teedev) {
ret = ERR_PTR(-ENOMEM);
goto err;
}
max_id = TEE_NUM_DEVICES / 2;
if (teedesc->flags & TEE_DESC_PRIVILEGED) {
offs = TEE_NUM_DEVICES / 2;
max_id = TEE_NUM_DEVICES;
}
spin_lock(&driver_lock);
teedev->id = find_next_zero_bit(dev_mask, max_id, offs);
if (teedev->id < max_id)
set_bit(teedev->id, dev_mask);
spin_unlock(&driver_lock);
if (teedev->id >= max_id) {
ret = ERR_PTR(-ENOMEM);
goto err;
}
snprintf(teedev->name, sizeof(teedev->name), "tee%s%d",
teedesc->flags & TEE_DESC_PRIVILEGED ? "priv" : "",
teedev->id - offs);
teedev->dev.class = tee_class;
teedev->dev.release = tee_release_device;
teedev->dev.parent = dev;
teedev->dev.devt = MKDEV(MAJOR(tee_devt), teedev->id);
rc = dev_set_name(&teedev->dev, "%s", teedev->name);
if (rc) {
ret = ERR_PTR(rc);
goto err_devt;
}
cdev_init(&teedev->cdev, &tee_fops);
teedev->cdev.owner = teedesc->owner;
teedev->cdev.kobj.parent = &teedev->dev.kobj;
dev_set_drvdata(&teedev->dev, driver_data);
device_initialize(&teedev->dev);
/* 1 as tee_device_unregister() does one final tee_device_put() */
teedev->num_users = 1;
init_completion(&teedev->c_no_users);
mutex_init(&teedev->mutex);
idr_init(&teedev->idr);
teedev->desc = teedesc;
teedev->pool = pool;
return teedev;
err_devt:
unregister_chrdev_region(teedev->dev.devt, 1);
err:
pr_err("could not register %s driver\n",
teedesc->flags & TEE_DESC_PRIVILEGED ? "privileged" : "client");
if (teedev && teedev->id < TEE_NUM_DEVICES) {
spin_lock(&driver_lock);
clear_bit(teedev->id, dev_mask);
spin_unlock(&driver_lock);
}
kfree(teedev);
return ret;
}
EXPORT_SYMBOL_GPL(tee_device_alloc);
static ssize_t implementation_id_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct tee_device *teedev = container_of(dev, struct tee_device, dev);
struct tee_ioctl_version_data vers;
teedev->desc->ops->get_version(teedev, &vers);
return scnprintf(buf, PAGE_SIZE, "%d\n", vers.impl_id);
}
static DEVICE_ATTR_RO(implementation_id);
static struct attribute *tee_dev_attrs[] = {
&dev_attr_implementation_id.attr,
NULL
};
static const struct attribute_group tee_dev_group = {
.attrs = tee_dev_attrs,
};
/**
* tee_device_register() - Registers a TEE device
* @teedev: Device to register
*
* tee_device_unregister() need to be called to remove the @teedev if
* this function fails.
*
* @returns < 0 on failure
*/
int tee_device_register(struct tee_device *teedev)
{
int rc;
if (teedev->flags & TEE_DEVICE_FLAG_REGISTERED) {
dev_err(&teedev->dev, "attempt to register twice\n");
return -EINVAL;
}
rc = cdev_add(&teedev->cdev, teedev->dev.devt, 1);
if (rc) {
dev_err(&teedev->dev,
"unable to cdev_add() %s, major %d, minor %d, err=%d\n",
teedev->name, MAJOR(teedev->dev.devt),
MINOR(teedev->dev.devt), rc);
return rc;
}
rc = device_add(&teedev->dev);
if (rc) {
dev_err(&teedev->dev,
"unable to device_add() %s, major %d, minor %d, err=%d\n",
teedev->name, MAJOR(teedev->dev.devt),
MINOR(teedev->dev.devt), rc);
goto err_device_add;
}
rc = sysfs_create_group(&teedev->dev.kobj, &tee_dev_group);
if (rc) {
dev_err(&teedev->dev,
"failed to create sysfs attributes, err=%d\n", rc);
goto err_sysfs_create_group;
}
teedev->flags |= TEE_DEVICE_FLAG_REGISTERED;
return 0;
err_sysfs_create_group:
device_del(&teedev->dev);
err_device_add:
cdev_del(&teedev->cdev);
return rc;
}
EXPORT_SYMBOL_GPL(tee_device_register);
void tee_device_put(struct tee_device *teedev)
{
mutex_lock(&teedev->mutex);
/* Shouldn't put in this state */
if (!WARN_ON(!teedev->desc)) {
teedev->num_users--;
if (!teedev->num_users) {
teedev->desc = NULL;
complete(&teedev->c_no_users);
}
}
mutex_unlock(&teedev->mutex);
}
bool tee_device_get(struct tee_device *teedev)
{
mutex_lock(&teedev->mutex);
if (!teedev->desc) {
mutex_unlock(&teedev->mutex);
return false;
}
teedev->num_users++;
mutex_unlock(&teedev->mutex);
return true;
}
/**
* tee_device_unregister() - Removes a TEE device
* @teedev: Device to unregister
*
* This function should be called to remove the @teedev even if
* tee_device_register() hasn't been called yet. Does nothing if
* @teedev is NULL.
*/
void tee_device_unregister(struct tee_device *teedev)
{
if (!teedev)
return;
if (teedev->flags & TEE_DEVICE_FLAG_REGISTERED) {
sysfs_remove_group(&teedev->dev.kobj, &tee_dev_group);
cdev_del(&teedev->cdev);
device_del(&teedev->dev);
}
tee_device_put(teedev);
wait_for_completion(&teedev->c_no_users);
/*
* No need to take a mutex any longer now since teedev->desc was
* set to NULL before teedev->c_no_users was completed.
*/
teedev->pool = NULL;
put_device(&teedev->dev);
}
EXPORT_SYMBOL_GPL(tee_device_unregister);
/**
* tee_get_drvdata() - Return driver_data pointer
* @teedev: Device containing the driver_data pointer
* @returns the driver_data pointer supplied to tee_register().
*/
void *tee_get_drvdata(struct tee_device *teedev)
{
return dev_get_drvdata(&teedev->dev);
}
EXPORT_SYMBOL_GPL(tee_get_drvdata);
static int __init tee_init(void)
{
int rc;
tee_class = class_create(THIS_MODULE, "tee");
if (IS_ERR(tee_class)) {
pr_err("couldn't create class\n");
return PTR_ERR(tee_class);
}
rc = alloc_chrdev_region(&tee_devt, 0, TEE_NUM_DEVICES, "tee");
if (rc) {
pr_err("failed to allocate char dev region\n");
class_destroy(tee_class);
tee_class = NULL;
}
return rc;
}
static void __exit tee_exit(void)
{
class_destroy(tee_class);
tee_class = NULL;
unregister_chrdev_region(tee_devt, TEE_NUM_DEVICES);
}
subsys_initcall(tee_init);
module_exit(tee_exit);
MODULE_AUTHOR("Linaro");
MODULE_DESCRIPTION("TEE Driver");
MODULE_VERSION("1.0");
MODULE_LICENSE("GPL v2");