[PATCH v2 09/12] tee: add tee_shm_register_{user,kernel}_buf()

From: Jens Wiklander
Date: Fri Jan 14 2022 - 10:09:26 EST


Adds the two new functions tee_shm_register_user_buf() and
tee_shm_register_kernel_buf() which should be used instead of the old
tee_shm_register().

This avoids having the caller supplying the flags parameter which
exposes a bit more than desired of the internals of the TEE subsystem.

Signed-off-by: Jens Wiklander <jens.wiklander@xxxxxxxxxx>
---
drivers/tee/tee_core.c | 3 +--
drivers/tee/tee_shm.c | 34 ++++++++++++++++++++++++++++++++++
include/linux/tee_drv.h | 4 ++++
3 files changed, 39 insertions(+), 2 deletions(-)

diff --git a/drivers/tee/tee_core.c b/drivers/tee/tee_core.c
index a15812baaeb1..8aa1a4836b92 100644
--- a/drivers/tee/tee_core.c
+++ b/drivers/tee/tee_core.c
@@ -334,8 +334,7 @@ tee_ioctl_shm_register(struct tee_context *ctx,
if (data.flags)
return -EINVAL;

- shm = tee_shm_register(ctx, data.addr, data.length,
- TEE_SHM_DMA_BUF | TEE_SHM_USER_MAPPED);
+ shm = tee_shm_register_user_buf(ctx, data.addr, data.length);
if (IS_ERR(shm))
return PTR_ERR(shm);

diff --git a/drivers/tee/tee_shm.c b/drivers/tee/tee_shm.c
index d51bf97ce7e5..6a1dbce75616 100644
--- a/drivers/tee/tee_shm.c
+++ b/drivers/tee/tee_shm.c
@@ -301,6 +301,40 @@ struct tee_shm *tee_shm_register(struct tee_context *ctx, unsigned long addr,
}
EXPORT_SYMBOL_GPL(tee_shm_register);

+/**
+ * tee_shm_register_user_buf() - Register a userspace shared memory buffer
+ * @ctx: Context that registers the shared memory
+ * @addr: The userspace address of the shared buffer
+ * @length: Length of the shared buffer
+ *
+ * @returns a pointer to 'struct tee_shm'
+ */
+struct tee_shm *tee_shm_register_user_buf(struct tee_context *ctx,
+ unsigned long addr, size_t length)
+{
+ return tee_shm_register(ctx, addr, length,
+ TEE_SHM_DMA_BUF | TEE_SHM_USER_MAPPED);
+}
+EXPORT_SYMBOL_GPL(tee_shm_register_user_buf);
+
+/**
+ * tee_shm_register_kernel_buf() - Register kernel memory to be shared with
+ * secure world
+ * @ctx: Context that registers the shared memory
+ * @addr: The buffer
+ * @length: Length of the buffer
+ *
+ * @returns a pointer to 'struct tee_shm'
+ */
+
+struct tee_shm *tee_shm_register_kernel_buf(struct tee_context *ctx,
+ void *addr, size_t length)
+{
+ return tee_shm_register(ctx, (unsigned long)addr, length,
+ TEE_SHM_DMA_BUF | TEE_SHM_KERNEL_MAPPED);
+}
+EXPORT_SYMBOL_GPL(tee_shm_register_kernel_buf);
+
static int tee_shm_fop_release(struct inode *inode, struct file *filp)
{
tee_shm_put(filp->private_data);
diff --git a/include/linux/tee_drv.h b/include/linux/tee_drv.h
index e71cb0411e9c..029c9a0590cc 100644
--- a/include/linux/tee_drv.h
+++ b/include/linux/tee_drv.h
@@ -289,6 +289,10 @@ struct tee_shm *tee_shm_alloc_kernel_buf(struct tee_context *ctx, size_t size);
*/
struct tee_shm *tee_shm_register(struct tee_context *ctx, unsigned long addr,
size_t length, u32 flags);
+struct tee_shm *tee_shm_register_user_buf(struct tee_context *ctx,
+ unsigned long addr, size_t length);
+struct tee_shm *tee_shm_register_kernel_buf(struct tee_context *ctx,
+ void *addr, size_t length);

/**
* tee_shm_is_registered() - Check if shared memory object in registered in TEE
--
2.31.1