Re: [PATCH v2 3/8] tee: add TEE_IOCTL_PARAM_ATTR_TYPE_UBUF

On 2/17/2025 9:10 PM, Jens Wiklander wrote:

On Sun, Feb 02, 2025 at 06:43:31PM -0800, Amirreza Zarrabi wrote:

...

For drivers that can transfer data to the TEE without using shared memory from client, it is necessary to receive the user address directly, bypassing any processing by the TEE subsystem. Introduce TEE_IOCTL_PARAM_ATTR_TYPE_UBUF_INPUT/OUTPUT/INOUT to represent userspace buffers.

Signed-off-by: Amirreza Zarrabi quic_azarrabi@quicinc.com

drivers/tee/tee_core.c | 27 +++++++++++++++++++++++++++ include/linux/tee_drv.h | 6 ++++++ include/uapi/linux/tee.h | 22 ++++++++++++++++------ 3 files changed, 49 insertions(+), 6 deletions(-)

diff --git a/drivers/tee/tee_core.c b/drivers/tee/tee_core.c index 721522fe5c63..9f4b9a995e16 100644 --- a/drivers/tee/tee_core.c +++ b/drivers/tee/tee_core.c @@ -386,6 +386,16 @@ static int params_from_user(struct tee_context *ctx, struct tee_param *params, params[n].u.value.b = ip.b; params[n].u.value.c = ip.c; break;

• case TEE_IOCTL_PARAM_ATTR_TYPE_UBUF_INPUT:
  

• case TEE_IOCTL_PARAM_ATTR_TYPE_UBUF_OUTPUT:
  

• case TEE_IOCTL_PARAM_ATTR_TYPE_UBUF_INOUT:
  

• 	params[n].u.ubuf.uaddr = u64_to_user_ptr(ip.a);
  

• 	params[n].u.ubuf.size = ip.b;
  

• 	if (!access_ok(params[n].u.ubuf.uaddr, params[n].u.ubuf.size))
  

This line is over 80 columns, https://docs.kernel.org/process/coding-style.html#breaking-long-lines-and-st...

...

• 		return -EFAULT;
  

• 	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:

@@ -454,6 +464,11 @@ static int params_to_user(struct tee_ioctl_param __user *uparams, put_user(p->u.value.c, &up->c)) return -EFAULT; break;

• case TEE_IOCTL_PARAM_ATTR_TYPE_UBUF_OUTPUT:
  

• case TEE_IOCTL_PARAM_ATTR_TYPE_UBUF_INOUT:
  

• 	if (put_user((u64)p->u.ubuf.size, &up->b))
  

• 		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))

@@ -654,6 +669,13 @@ static int params_to_supp(struct tee_context *ctx, ip.b = p->u.value.b; ip.c = p->u.value.c; break;

• case TEE_IOCTL_PARAM_ATTR_TYPE_UBUF_INPUT:
  

• case TEE_IOCTL_PARAM_ATTR_TYPE_UBUF_OUTPUT:
  

• case TEE_IOCTL_PARAM_ATTR_TYPE_UBUF_INOUT:
  

• 	ip.a = (u64)p->u.ubuf.uaddr;
  

• 	ip.b = p->u.ubuf.size;
  

• 	ip.c = 0;
  

• 	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:

@@ -756,6 +778,11 @@ static int params_from_supp(struct tee_param *params, size_t num_params, p->u.value.b = ip.b; p->u.value.c = ip.c; break;

• case TEE_IOCTL_PARAM_ATTR_TYPE_UBUF_OUTPUT:
  

• case TEE_IOCTL_PARAM_ATTR_TYPE_UBUF_INOUT:
  

• 	p->u.ubuf.uaddr = u64_to_user_ptr(ip.a);
  

Is this needed? Compare with how TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_* is handled below. If it's indeed needed, please add an access_ok() check.

Yes, it is needed. Unlike the MEMREF which is a fixed memory range, UBUF can be any user memory range, for instance if it is comming from a readonly secion, it is easier for user to update the address, size pair rather than copying it.

Sorry I missed the access_ok here. I'll add.

...

• 	p->u.ubuf.size = ip.b;
  

• 	break;
  

  case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT: case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INOUT: /*

diff --git a/include/linux/tee_drv.h b/include/linux/tee_drv.h index d5f0c70ac95c..130782d4d5f6 100644 --- a/include/linux/tee_drv.h +++ b/include/linux/tee_drv.h @@ -82,6 +82,11 @@ struct tee_param_memref { struct tee_shm *shm; }; +struct tee_param_ubuf {

• void * __user uaddr;
• size_t size;

+};

struct tee_param_value { u64 a; u64 b; @@ -92,6 +97,7 @@ struct tee_param { u64 attr; union { struct tee_param_memref memref;

• struct tee_param_ubuf ubuf;
  

  struct tee_param_value value; } u;

}; diff --git a/include/uapi/linux/tee.h b/include/uapi/linux/tee.h index d0430bee8292..4a1dcfb4290e 100644 --- a/include/uapi/linux/tee.h +++ b/include/uapi/linux/tee.h @@ -151,6 +151,13 @@ struct tee_ioctl_buf_data { #define TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT 6 #define TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INOUT 7 /* input and output */ +/*

• • These defines userspace buffer parameters.
• */

+#define TEE_IOCTL_PARAM_ATTR_TYPE_UBUF_INPUT 8 +#define TEE_IOCTL_PARAM_ATTR_TYPE_UBUF_OUTPUT 9 +#define TEE_IOCTL_PARAM_ATTR_TYPE_UBUF_INOUT 10 /* input and output */

/*

• Mask for the type part of the attribute, leaves room for more types

*/ @@ -186,14 +193,17 @@ struct tee_ioctl_buf_data { /**

• struct tee_ioctl_param - parameter
• @attr: attributes

• • @a: if a memref, offset into the shared memory object, else a value parameter
• • @b: if a memref, size of the buffer, else a value parameter

• • @a: if a memref, offset into the shared memory object,

• • else if a ubuf, address into the user buffer,
    

address _of_ the user buffer?

Thanks, Jens

Ack.

Thanks, Amir

...

• • else a value parameter
    

• • @b: if a memref or ubuf, size of the buffer, else a value parameter
  • @c: if a memref, shared memory identifier, else a value parameter

• • @attr & TEE_PARAM_ATTR_TYPE_MASK indicates if memref or value is used in
• • the union. TEE_PARAM_ATTR_TYPE_VALUE_* indicates value and
• • TEE_PARAM_ATTR_TYPE_MEMREF_* indicates memref. TEE_PARAM_ATTR_TYPE_NONE
• • indicates that none of the members are used.

• • @attr & TEE_PARAM_ATTR_TYPE_MASK indicates if memref, ubuf, or value is
• • used in the union. TEE_PARAM_ATTR_TYPE_VALUE_* indicates value,
• • TEE_PARAM_ATTR_TYPE_MEMREF_* indicates memref, and TEE_PARAM_ATTR_TYPE_UBUF_*
• • indicates ubuf. TEE_PARAM_ATTR_TYPE_NONE indicates that none of the members
• • are used.
  • Shared memory is allocated with TEE_IOC_SHM_ALLOC which returns an
  • identifier representing the shared memory object. A memref can reference

-- 2.34.1