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tee: add register user memory
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Added new ioctl to allow users register own buffers as a shared memory.

Signed-off-by: Volodymyr Babchuk <vlad.babchuk@gmail.com>
[jw: moved tee_shm_is_registered() declaration]
[jw: added space after __tee_shm_alloc() implementation]
Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
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@jenswi-linaro
jenswi-linaro committed Dec 15, 2017
1 parent e2aca5d commit 033ddf1
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Showing 4 changed files with 294 additions and 30 deletions.
41 changes: 39 additions & 2 deletions drivers/tee/tee_core.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -114,8 +114,6 @@ static int tee_ioctl_shm_alloc(struct tee_context *ctx,
if (data.flags)
return -EINVAL;

data.id = -1;

shm = tee_shm_alloc(ctx, data.size, TEE_SHM_MAPPED | TEE_SHM_DMA_BUF);
if (IS_ERR(shm))
return PTR_ERR(shm);
Expand All @@ -138,6 +136,43 @@ static int tee_ioctl_shm_alloc(struct tee_context *ctx,
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)
Expand Down Expand Up @@ -586,6 +621,8 @@ static long tee_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
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:
Expand Down
206 changes: 180 additions & 26 deletions drivers/tee/tee_shm.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -23,20 +23,36 @@
static void tee_shm_release(struct tee_shm *shm)
{
struct tee_device *teedev = shm->teedev;
struct tee_shm_pool_mgr *poolm;

mutex_lock(&teedev->mutex);
idr_remove(&teedev->idr, shm->id);
if (shm->ctx)
list_del(&shm->link);
mutex_unlock(&teedev->mutex);

if (shm->flags & TEE_SHM_DMA_BUF)
poolm = teedev->pool->dma_buf_mgr;
else
poolm = teedev->pool->private_mgr;
if (shm->flags & TEE_SHM_POOL) {
struct tee_shm_pool_mgr *poolm;

if (shm->flags & TEE_SHM_DMA_BUF)
poolm = teedev->pool->dma_buf_mgr;
else
poolm = teedev->pool->private_mgr;

poolm->ops->free(poolm, shm);
} else if (shm->flags & TEE_SHM_REGISTER) {
size_t n;
int rc = teedev->desc->ops->shm_unregister(shm->ctx, shm);

if (rc)
dev_err(teedev->dev.parent,
"unregister shm %p failed: %d", shm, rc);

for (n = 0; n < shm->num_pages; n++)
put_page(shm->pages[n]);

kfree(shm->pages);
}

poolm->ops->free(poolm, shm);
kfree(shm);

tee_device_put(teedev);
Expand Down Expand Up @@ -76,6 +92,10 @@ static int tee_shm_op_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma)
struct tee_shm *shm = dmabuf->priv;
size_t size = vma->vm_end - vma->vm_start;

/* Refuse sharing shared memory provided by application */
if (shm->flags & TEE_SHM_REGISTER)
return -EINVAL;

return remap_pfn_range(vma, vma->vm_start, shm->paddr >> PAGE_SHIFT,
size, vma->vm_page_prot);
}
Expand All @@ -89,26 +109,20 @@ static const struct dma_buf_ops tee_shm_dma_buf_ops = {
.mmap = tee_shm_op_mmap,
};

/**
* tee_shm_alloc() - Allocate shared memory
* @ctx: Context that allocates the shared memory
* @size: Requested size of shared memory
* @flags: Flags setting properties for the requested shared memory.
*
* Memory allocated as global shared memory is automatically freed when the
* TEE file pointer is closed. The @flags field uses the bits defined by
* TEE_SHM_* in <linux/tee_drv.h>. TEE_SHM_MAPPED must currently always be
* set. If TEE_SHM_DMA_BUF global shared memory will be allocated and
* associated with a dma-buf handle, else driver private memory.
*/
struct tee_shm *tee_shm_alloc(struct tee_context *ctx, size_t size, u32 flags)
struct tee_shm *__tee_shm_alloc(struct tee_context *ctx,
struct tee_device *teedev,
size_t size, u32 flags)
{
struct tee_device *teedev = ctx->teedev;
struct tee_shm_pool_mgr *poolm = NULL;
struct tee_shm *shm;
void *ret;
int rc;

if (ctx && ctx->teedev != teedev) {
dev_err(teedev->dev.parent, "ctx and teedev mismatch\n");
return ERR_PTR(-EINVAL);
}

if (!(flags & TEE_SHM_MAPPED)) {
dev_err(teedev->dev.parent,
"only mapped allocations supported\n");
Expand All @@ -135,7 +149,7 @@ struct tee_shm *tee_shm_alloc(struct tee_context *ctx, size_t size, u32 flags)
goto err_dev_put;
}

shm->flags = flags;
shm->flags = flags | TEE_SHM_POOL;
shm->teedev = teedev;
shm->ctx = ctx;
if (flags & TEE_SHM_DMA_BUF)
Expand Down Expand Up @@ -171,9 +185,12 @@ struct tee_shm *tee_shm_alloc(struct tee_context *ctx, size_t size, u32 flags)
goto err_rem;
}
}
mutex_lock(&teedev->mutex);
list_add_tail(&shm->link, &ctx->list_shm);
mutex_unlock(&teedev->mutex);

if (ctx) {
mutex_lock(&teedev->mutex);
list_add_tail(&shm->link, &ctx->list_shm);
mutex_unlock(&teedev->mutex);
}

return shm;
err_rem:
Expand All @@ -188,19 +205,150 @@ struct tee_shm *tee_shm_alloc(struct tee_context *ctx, size_t size, u32 flags)
tee_device_put(teedev);
return ret;
}

/**
* tee_shm_alloc() - Allocate shared memory
* @ctx: Context that allocates the shared memory
* @size: Requested size of shared memory
* @flags: Flags setting properties for the requested shared memory.
*
* Memory allocated as global shared memory is automatically freed when the
* TEE file pointer is closed. The @flags field uses the bits defined by
* TEE_SHM_* in <linux/tee_drv.h>. TEE_SHM_MAPPED must currently always be
* set. If TEE_SHM_DMA_BUF global shared memory will be allocated and
* associated with a dma-buf handle, else driver private memory.
*/
struct tee_shm *tee_shm_alloc(struct tee_context *ctx, size_t size, u32 flags)
{
return __tee_shm_alloc(ctx, ctx->teedev, size, flags);
}
EXPORT_SYMBOL_GPL(tee_shm_alloc);

struct tee_shm *tee_shm_priv_alloc(struct tee_device *teedev, size_t size)
{
return __tee_shm_alloc(NULL, teedev, size, TEE_SHM_MAPPED);
}
EXPORT_SYMBOL_GPL(tee_shm_priv_alloc);

struct tee_shm *tee_shm_register(struct tee_context *ctx, unsigned long addr,
size_t length, u32 flags)
{
struct tee_device *teedev = ctx->teedev;
const u32 req_flags = TEE_SHM_DMA_BUF | TEE_SHM_USER_MAPPED;
struct tee_shm *shm;
void *ret;
int rc;
int num_pages;
unsigned long start;

if (flags != req_flags)
return ERR_PTR(-ENOTSUPP);

if (!tee_device_get(teedev))
return ERR_PTR(-EINVAL);

if (!teedev->desc->ops->shm_register ||
!teedev->desc->ops->shm_unregister) {
tee_device_put(teedev);
return ERR_PTR(-ENOTSUPP);
}

shm = kzalloc(sizeof(*shm), GFP_KERNEL);
if (!shm) {
ret = ERR_PTR(-ENOMEM);
goto err;
}

shm->flags = flags | TEE_SHM_REGISTER;
shm->teedev = teedev;
shm->ctx = ctx;
shm->id = -1;
start = rounddown(addr, PAGE_SIZE);
shm->offset = addr - start;
shm->size = length;
num_pages = (roundup(addr + length, PAGE_SIZE) - start) / PAGE_SIZE;
shm->pages = kcalloc(num_pages, sizeof(*shm->pages), GFP_KERNEL);
if (!shm->pages) {
ret = ERR_PTR(-ENOMEM);
goto err;
}

rc = get_user_pages_fast(start, num_pages, 1, shm->pages);
if (rc > 0)
shm->num_pages = rc;
if (rc != num_pages) {
if (rc > 0)
rc = -ENOMEM;
ret = ERR_PTR(rc);
goto err;
}

mutex_lock(&teedev->mutex);
shm->id = idr_alloc(&teedev->idr, shm, 1, 0, GFP_KERNEL);
mutex_unlock(&teedev->mutex);

if (shm->id < 0) {
ret = ERR_PTR(shm->id);
goto err;
}

rc = teedev->desc->ops->shm_register(ctx, shm, shm->pages,
shm->num_pages);
if (rc) {
ret = ERR_PTR(rc);
goto err;
}

if (flags & TEE_SHM_DMA_BUF) {
DEFINE_DMA_BUF_EXPORT_INFO(exp_info);

exp_info.ops = &tee_shm_dma_buf_ops;
exp_info.size = shm->size;
exp_info.flags = O_RDWR;
exp_info.priv = shm;

shm->dmabuf = dma_buf_export(&exp_info);
if (IS_ERR(shm->dmabuf)) {
ret = ERR_CAST(shm->dmabuf);
teedev->desc->ops->shm_unregister(ctx, shm);
goto err;
}
}

mutex_lock(&teedev->mutex);
list_add_tail(&shm->link, &ctx->list_shm);
mutex_unlock(&teedev->mutex);

return shm;
err:
if (shm) {
size_t n;

if (shm->id >= 0) {
mutex_lock(&teedev->mutex);
idr_remove(&teedev->idr, shm->id);
mutex_unlock(&teedev->mutex);
}
for (n = 0; n < shm->num_pages; n++)
put_page(shm->pages[n]);
kfree(shm->pages);
}
kfree(shm);
tee_device_put(teedev);
return ret;
}
EXPORT_SYMBOL_GPL(tee_shm_register);

/**
* tee_shm_get_fd() - Increase reference count and return file descriptor
* @shm: Shared memory handle
* @returns user space file descriptor to shared memory
*/
int tee_shm_get_fd(struct tee_shm *shm)
{
u32 req_flags = TEE_SHM_MAPPED | TEE_SHM_DMA_BUF;
int fd;

if ((shm->flags & req_flags) != req_flags)
if (!(shm->flags & TEE_SHM_DMA_BUF))
return -EINVAL;

fd = dma_buf_fd(shm->dmabuf, O_CLOEXEC);
Expand Down Expand Up @@ -238,6 +386,8 @@ EXPORT_SYMBOL_GPL(tee_shm_free);
*/
int tee_shm_va2pa(struct tee_shm *shm, void *va, phys_addr_t *pa)
{
if (!(shm->flags & TEE_SHM_MAPPED))
return -EINVAL;
/* Check that we're in the range of the shm */
if ((char *)va < (char *)shm->kaddr)
return -EINVAL;
Expand All @@ -258,6 +408,8 @@ EXPORT_SYMBOL_GPL(tee_shm_va2pa);
*/
int tee_shm_pa2va(struct tee_shm *shm, phys_addr_t pa, void **va)
{
if (!(shm->flags & TEE_SHM_MAPPED))
return -EINVAL;
/* Check that we're in the range of the shm */
if (pa < shm->paddr)
return -EINVAL;
Expand All @@ -284,6 +436,8 @@ EXPORT_SYMBOL_GPL(tee_shm_pa2va);
*/
void *tee_shm_get_va(struct tee_shm *shm, size_t offs)
{
if (!(shm->flags & TEE_SHM_MAPPED))
return ERR_PTR(-EINVAL);
if (offs >= shm->size)
return ERR_PTR(-EINVAL);
return (char *)shm->kaddr + offs;
Expand Down
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