[PATCH v3 03/11] tee: add TEE_IOCTL_PARAM_ATTR_TYPE_UBUF
Amirreza Zarrabi
amirreza.zarrabi at oss.qualcomm.com
Wed Apr 9 07:20:08 UTC 2025
On 4/9/2025 4:41 PM, Jens Wiklander wrote:
> Hi Amirreza,
>
> On Wed, Apr 9, 2025 at 2:28 AM Amirreza Zarrabi
> <amirreza.zarrabi at oss.qualcomm.com> wrote:
>>
>> Hi jens,
>>
>> On 4/8/2025 10:19 PM, Jens Wiklander wrote:
>>
>> Hi Amirreza,
>>
>> On Fri, Mar 28, 2025 at 3:48 AM Amirreza Zarrabi
>> <amirreza.zarrabi at oss.qualcomm.com> 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 <amirreza.zarrabi at oss.qualcomm.com>
>> ---
>> drivers/tee/tee_core.c | 33 +++++++++++++++++++++++++++++++++
>> include/linux/tee_drv.h | 6 ++++++
>> include/uapi/linux/tee.h | 22 ++++++++++++++++------
>> 3 files changed, 55 insertions(+), 6 deletions(-)
>>
>> Is this patch needed now that the QCOMTEE driver supports shared
>> memory? I prefer keeping changes to the ABI to a minimum.
>>
>> Cheers,
>> Jens
>>
>> Unfortunately, this is still required. QTEE supports two types of data transfer:
>> (1) using UBUF and (2) memory objects. Even with memory object support, some APIs still
>> expect to receive data using UBUF. For instance, to load a TA, QTEE offers two interfaces:
>> one where the TA binary is in UBUF and another where the TA binary is in a memory object.
>
> Is this a limitation in the QTEE backend driver or on the secure side?
> Can it be fixed? I don't ask for changes in the ABI to the secure
> world since I assume you haven't made such changes while this patch
> set has evolved.
>
> Cheers,
> Jens
The secure-side ABI supports passing data using memcpy to the same
buffer that contains the message for QTEE, rather than using a memory
object. Some services tend to use this approach for small data instead
of allocating a memory object. I have no choice but to expose this support.
Throughout the patchset, I have not made any change to the ABI but
tried to provide support for the memory object in a separate,
independent commit, distinct from the UBUF.
Best regards,
Amir
>
>>
>> Best Regards,
>> Amir
>>
>> diff --git a/drivers/tee/tee_core.c b/drivers/tee/tee_core.c
>> index 22cc7d624b0c..bc862a11d437 100644
>> --- a/drivers/tee/tee_core.c
>> +++ b/drivers/tee/tee_core.c
>> @@ -404,6 +404,17 @@ 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))
>> + 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:
>> @@ -472,6 +483,11 @@ 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))
>> @@ -672,6 +688,13 @@ 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:
>> @@ -774,6 +797,16 @@ 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);
>> + p->u.ubuf.size = ip.b;
>> +
>> + if (!access_ok(params[n].u.ubuf.uaddr,
>> + params[n].u.ubuf.size))
>> + return -EFAULT;
>> +
>> + 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 ce23fd42c5d4..d773f91c6bdd 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..3e9b1ec5dfde 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 of the user buffer,
>> + * 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
>>
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