On Thu, Jul 16, 2026 at 12:28:25PM +0530, Harshal Dev wrote:
Hi Amir,
On 7/15/2026 5:17 AM, Amirreza Zarrabi wrote:
Hi Harshal,
On 7/10/2026 4:37 PM, Harshal Dev wrote:
Hi Amir,
On 7/8/2026 11:31 AM, Amirreza Zarrabi wrote:
Hi Harshal,
On 7/7/2026 4:11 PM, Harshal Dev wrote:
QCOMTEE needs to distinguish between object invocations arriving from kernel clients and user-space clients in order to correctly marshal UBUF parameters and decide whether certain operations should be permitted.
Add a kernel_ctx flag to struct qcomtee_object_invoke_context to track the context of object invocation. Objects invoked from the kernel-space are expected to have the MSB of their 64-bit object-id set to indicate a kernel context, whereas objects invoked from user-space should not set it. To ensure this, we restrict the object-id space of user-space invoked objects to 32-bits. This is in-line with QTEE expectation of 32-bit object ids.
Signed-off-by: Amirreza Zarrabi amirreza.zarrabi@oss.qualcomm.com Signed-off-by: Harshal Dev harshal.dev@oss.qualcomm.com
drivers/tee/qcomtee/call.c | 24 ++++++++++++++++++++++-- drivers/tee/qcomtee/qcomtee.h | 6 ++++++ drivers/tee/qcomtee/qcomtee_object.h | 8 ++++++-- drivers/tee/tee_core.c | 4 ++++ 4 files changed, 38 insertions(+), 4 deletions(-)
diff --git a/drivers/tee/qcomtee/call.c b/drivers/tee/qcomtee/call.c index 0efc5646242a..a74a54d67b06 100644 --- a/drivers/tee/qcomtee/call.c +++ b/drivers/tee/qcomtee/call.c @@ -397,11 +397,31 @@ static int qcomtee_object_invoke(struct tee_context *ctx, { struct qcomtee_context_data *ctxdata = ctx->data; struct qcomtee_object *object;
- bool kernel_ctx = false; int i, ret, result;
if (qcomtee_params_check(params, arg->num_params)) return -EINVAL;
- /* Obtain the invocation context information from the MSB of the object
* `id` field.*/- kernel_ctx = QCOMTEE_GET_CLIENT_CTX(arg->id);
- /* User-space identifies a NULL object via a 32-bit TEE_OBJREF_NULL id, whereas
* the kernel uses as 64-bit object-id. Hence, we check for a NULL object by* sign-extending the object-id to 64 bits. If user-space is indeed invoking a* NULL object we must extend the object-id to 64-bits from here on so that* QCOMTEE can recognize it.*/- if (!kernel_ctx && ((s64)(s32)arg->id) == TEE_OBJREF_NULL)
arg->id = TEE_OBJREF_NULL;Does it need to be MSB -- why bit 63? the object ID supported by QTEE is 32-bit anyway. Let's mask the upper 32-bit and do something like kernel_ctx = !!upper_32_bits(id). What do you think?
I agree. Instead of checking for kernel-ctx by right shifting, I can use this approach. QTEE objects invoked from user-space (including NULL object) will always have their object-id constrained to lower 32 bits anyway as per PR: https://github.com/quic/quic-teec/pull/27
And for kernel-space invoked QTEE objects, upper 32-bits would be set for NULL object, and 63rd bit expected to be set as well.
Re-thinking this, I'm a bit concerned about overloading id while keeping it as a u64, and then filtering its upper 32 bits in tee_ioctl_object_invoke(). It feels unintuitive, as it naturally raises the question: if only the lower 32 bits are meaningful, why is id a `u64` in the first place?
What if we make the caller origin explicit instead, for example:
enum tee_object_invoke_origin { TEE_OBJECT_INVOKE_USERSPACE, TEE_OBJECT_INVOKE_KERNEL, };
and then pass it through the backend op:
int (*object_invoke_func)(struct tee_context *ctx, struct tee_ioctl_object_invoke_arg *arg, struct tee_param *param, enum tee_object_invoke_origin origin);
It seems more straightforward and avoids encoding caller-origin metadata into id. If you are OK, let's do this.
Honestly, this approach makes everything a lot more easier, since we don't need complex bit manipulation in back-end to filter the upper 32 bits and handle the case of TEE_OBJREF_NULL. I can also then drop the PR: https://github.com/quic/quic-teec/pull/27
I am fine with updating this callback and calling it with TEE_OBJECT_INVOKE_USERSPACE from https://elixir.bootlin.com/linux/v7.1/source/drivers/tee/tee_core.c#L704 and TEE_OBJECT_INVOKE_KERNEL from the newly introduced tee_client_object_invoke_func().
But is there any special reason for choosing an enum over a boolean value here? Are we planning to extend the enum later to introduce any other context information?
I think enum is just better to provide enough info for the flag.
I am fine with this approach. I hope the OP-TEE maintainers @Sumit are fine as well with the new parameter addition in the callback.
That's fine with me if it simplifies the object handling for you folks.
-Sumit