Re: [PATCH] tee: optee: Fix supplicant based device enumeration

[Jan Kiszka <jan.kiszka@siemens.com>]

On 07.06.23 17:14, Sumit Garg wrote:
> Currently supplicant dependent optee device enumeration only registers
> devices whenever tee-supplicant is invoked for the first time. But it
> forgets to remove devices when tee-supplicant daemon stops running and
> closes its context gracefully. This leads to following splats for fTPM
> driver during reboot/shutdown:
> 
> [   73.466791] tpm tpm0: ftpm_tee_tpm_op_send: SUBMIT_COMMAND invoke error: 0xffff3024
> [   73.474497] ------------[ cut here ]------------
> [   73.479119] WARNING: CPU: 1 PID: 1 at drivers/char/tpm/tpm_ftpm_tee.c:135 ftpm_tee_tpm_op_send+0x200/0x25c
> <snip>
> [   73.539952] pstate: 60000005 (nZCv daif -PAN -UAO -TCO BTYPE=--)
> [   73.545946] pc : ftpm_tee_tpm_op_send+0x200/0x25c
> [   73.550640] lr : ftpm_tee_tpm_op_send+0x200/0x25c
> [   73.555331] sp : ffff80001129baa0
> [   73.558635] x29: ffff80001129baa0 x28: ffff00000646f000
> [   73.563938] x27: ffff8000110f7000 x26: 0000000000000016
> [   73.569241] x25: 0000000000000145 x24: ffff000005395000
> [   73.574544] x23: ffff0000065a7280 x22: ffff00000646f000
> [   73.579847] x21: ffff000006422080 x20: 000000000000000c
> [   73.585149] x19: 0000000000000000 x18: 0000000000000000
> [   73.590450] x17: 0000000000000000 x16: 0000000000000000
> [   73.595753] x15: 0000000000000030 x14: ffffffffffffffff
> [   73.601055] x13: ffff80001110e838 x12: 00000000000006d2
> [   73.606357] x11: 0000000000000246 x10: ffff800011166838
> [   73.611659] x9 : 00000000fffff000 x8 : ffff80001110e838
> [   73.616962] x7 : ffff800011166838 x6 : 0000000000000000
> [   73.622263] x5 : 0000000000000000 x4 : 0000000000000000
> [   73.627565] x3 : 0000000000000000 x2 : 0000000000000000
> [   73.632867] x1 : 0000000000000000 x0 : ffff0000000e8000
> [   73.638170] Call trace:
> [   73.640610]  ftpm_tee_tpm_op_send+0x200/0x25c
> [   73.644960]  tpm_transmit+0xc8/0x33c
> [   73.648528]  tpm_transmit_cmd+0x30/0xc0
> [   73.652353]  tpm2_shutdown+0xa4/0x100
> [   73.656007]  tpm_class_shutdown+0x60/0x90
> [   73.660009]  device_shutdown+0x138/0x330
> [   73.663926]  __do_sys_reboot+0x218/0x2a0
> [   73.667839]  __arm64_sys_reboot+0x24/0x30
> [   73.671842]  el0_svc_common.constprop.0+0x78/0x1c4
> [   73.676622]  do_el0_svc+0x24/0x8c
> [   73.679932]  el0_svc+0x14/0x20
> [   73.682978]  el0_sync_handler+0xb0/0xb4
> [   73.686806]  el0_sync+0x180/0x1c0
> 
> Fix this properly by removing supplicant dependent devices when the
> supplicant closes gracefully. While at it use the global system
> workqueue for OP-TEE bus scanning work rather than our own custom one.
> 
> Reported-by: Jan Kiszka <jan.kiszka@siemens.com>
> Link: https://github.com/OP-TEE/optee_os/issues/6094
> Fixes: 5f178bb71e3a ("optee: enable support for multi-stage bus enumeration")
> Signed-off-by: Sumit Garg <sumit.garg@linaro.org>
> ---
>  drivers/tee/optee/core.c          | 26 +++++++++++---------------
>  drivers/tee/optee/device.c        | 27 ++++++++++++++++++++++++---
>  drivers/tee/optee/optee_private.h |  7 ++-----
>  3 files changed, 37 insertions(+), 23 deletions(-)
> 
> diff --git a/drivers/tee/optee/core.c b/drivers/tee/optee/core.c
> index d01ca47f7bde..e0f2c9cb0073 100644
> --- a/drivers/tee/optee/core.c
> +++ b/drivers/tee/optee/core.c
> @@ -15,7 +15,6 @@
>  #include <linux/string.h>
>  #include <linux/tee_drv.h>
>  #include <linux/types.h>
> -#include <linux/workqueue.h>
>  #include "optee_private.h"
>  
>  int optee_pool_op_alloc_helper(struct tee_shm_pool *pool, struct tee_shm *shm,
> @@ -84,6 +83,11 @@ static void optee_bus_scan(struct work_struct *work)
>  	WARN_ON(optee_enumerate_devices(PTA_CMD_GET_DEVICES_SUPP));
>  }
>  
> +static void optee_bus_remove(struct work_struct *work)
> +{
> +	optee_unregister_supp_devices();
> +}
> +
>  int optee_open(struct tee_context *ctx, bool cap_memref_null)
>  {
>  	struct optee_context_data *ctxdata;
> @@ -108,16 +112,8 @@ int optee_open(struct tee_context *ctx, bool cap_memref_null)
>  			return -EBUSY;
>  		}
>  
> -		if (!optee->scan_bus_done) {
> -			INIT_WORK(&optee->scan_bus_work, optee_bus_scan);
> -			optee->scan_bus_wq = create_workqueue("optee_bus_scan");
> -			if (!optee->scan_bus_wq) {
> -				kfree(ctxdata);
> -				return -ECHILD;
> -			}
> -			queue_work(optee->scan_bus_wq, &optee->scan_bus_work);
> -			optee->scan_bus_done = true;
> -		}
> +		INIT_WORK(&optee->scan_bus_work, optee_bus_scan);
> +		schedule_work(&optee->scan_bus_work);
>  	}
>  	mutex_init(&ctxdata->mutex);
>  	INIT_LIST_HEAD(&ctxdata->sess_list);
> @@ -159,10 +155,10 @@ void optee_release_supp(struct tee_context *ctx)
>  	struct optee *optee = tee_get_drvdata(ctx->teedev);
>  
>  	optee_release_helper(ctx, optee_close_session_helper);
> -	if (optee->scan_bus_wq) {
> -		destroy_workqueue(optee->scan_bus_wq);
> -		optee->scan_bus_wq = NULL;
> -	}
> +
> +	INIT_WORK(&optee->scan_bus_work, optee_bus_remove);
> +	schedule_work(&optee->scan_bus_work);
> +
>  	optee_supp_release(&optee->supp);
>  }
>  
> diff --git a/drivers/tee/optee/device.c b/drivers/tee/optee/device.c
> index 64f0e047c23d..88e1c3feb15d 100644
> --- a/drivers/tee/optee/device.c
> +++ b/drivers/tee/optee/device.c
> @@ -60,9 +60,10 @@ static void optee_release_device(struct device *dev)
>  	kfree(optee_device);
>  }
>  
> -static int optee_register_device(const uuid_t *device_uuid)
> +static int optee_register_device(const uuid_t *device_uuid, u32 func)
>  {
>  	struct tee_client_device *optee_device = NULL;
> +	const char *dev_name_fmt = NULL;
>  	int rc;
>  
>  	optee_device = kzalloc(sizeof(*optee_device), GFP_KERNEL);
> @@ -71,7 +72,13 @@ static int optee_register_device(const uuid_t *device_uuid)
>  
>  	optee_device->dev.bus = &tee_bus_type;
>  	optee_device->dev.release = optee_release_device;
> -	if (dev_set_name(&optee_device->dev, "optee-ta-%pUb", device_uuid)) {
> +
> +	if (func == PTA_CMD_GET_DEVICES_SUPP)
> +		dev_name_fmt = "optee-ta-supp-%pUb";
> +	else
> +		dev_name_fmt = "optee-ta-%pUb";
> +
> +	if (dev_set_name(&optee_device->dev, dev_name_fmt, device_uuid)) {
>  		kfree(optee_device);
>  		return -ENOMEM;
>  	}
> @@ -142,7 +149,7 @@ static int __optee_enumerate_devices(u32 func)
>  	num_devices = shm_size / sizeof(uuid_t);
>  
>  	for (idx = 0; idx < num_devices; idx++) {
> -		rc = optee_register_device(&device_uuid[idx]);
> +		rc = optee_register_device(&device_uuid[idx], func);
>  		if (rc)
>  			goto out_shm;
>  	}
> @@ -175,3 +182,17 @@ void optee_unregister_devices(void)
>  	bus_for_each_dev(&tee_bus_type, NULL, NULL,
>  			 __optee_unregister_device);
>  }
> +
> +static int __optee_unregister_supp_device(struct device *dev, void *data)
> +{
> +	if (!strncmp(dev_name(dev), "optee-ta-supp", strlen("optee-ta-supp")))
> +		device_unregister(dev);
> +
> +	return 0;
> +}
> +
> +void optee_unregister_supp_devices(void)
> +{
> +	bus_for_each_dev(&tee_bus_type, NULL, NULL,
> +			 __optee_unregister_supp_device);
> +}
> diff --git a/drivers/tee/optee/optee_private.h b/drivers/tee/optee/optee_private.h
> index 6dcecb83c893..cb5eae6f797d 100644
> --- a/drivers/tee/optee/optee_private.h
> +++ b/drivers/tee/optee/optee_private.h
> @@ -192,9 +192,7 @@ struct optee_ops {
>   * @supp:		supplicant synchronization struct for RPC to supplicant
>   * @pool:		shared memory pool
>   * @rpc_param_count:	If > 0 number of RPC parameters to make room for
> - * @scan_bus_done	flag if device registation was already done.
> - * @scan_bus_wq		workqueue to scan optee bus and register optee drivers
> - * @scan_bus_work	workq to scan optee bus and register optee drivers
> + * @scan_bus_work	work to scan optee bus and register optee drivers
>   */
>  struct optee {
>  	struct tee_device *supp_teedev;
> @@ -211,8 +209,6 @@ struct optee {
>  	struct optee_supp supp;
>  	struct tee_shm_pool *pool;
>  	unsigned int rpc_param_count;
> -	bool   scan_bus_done;
> -	struct workqueue_struct *scan_bus_wq;
>  	struct work_struct scan_bus_work;
>  };
>  
> @@ -280,6 +276,7 @@ int optee_cancel_req(struct tee_context *ctx, u32 cancel_id, u32 session);
>  #define PTA_CMD_GET_DEVICES_SUPP	0x1
>  int optee_enumerate_devices(u32 func);
>  void optee_unregister_devices(void);
> +void optee_unregister_supp_devices(void);
>  
>  int optee_pool_op_alloc_helper(struct tee_shm_pool *pool, struct tee_shm *shm,
>  			       size_t size, size_t align,

I had to backport to 5.10 to use this, but maybe this is still generic:

[  201.223833] Unregistered efivars operations
[  201.228081] Registered efivars operations
[  OK  ] Stopped TEE Supplicant.
E/TC:? 0 get_rpc_alloc_res:645 RPC allocation failed. Non-secure world result: ret=0xffff000c ret_origin=0x2
E/TC:? 0 get_rpc_alloc_res:645 RPC allocation failed. Non-secure world result: ret=0xffff000c ret_origin=0x2
E/TC:? 0 
E/TC:? 0 TA panicked with code 0xffff000c
E/LD:  Status of TA bc50d971-d4c9-42c4-82cb-343fb7f37896
E/LD:   arch: aarch64
E/LD:  region  0: va 0x40004000 pa 0x9ee1a000 size 0x002000 flags rw-s (ldelf)
E/LD:  region  1: va 0x40006000 pa 0x9ee1c000 size 0x008000 flags r-xs (ldelf)
E/LD:  region  2: va 0x4000e000 pa 0x9ee24000 size 0x001000 flags rw-s (ldelf)
E/LD:  region  3: va 0x4000f000 pa 0x9ee25000 size 0x004000 flags rw-s (ldelf)
[  OK  ] Stopped Modem Manager.
E/LD:  region  4: va 0x40013000 pa 0x9ee29000 size 0x001000 flags r--s
E/LD:  region  5: va 0x40014000 pa 0x9eeb0000 size 0x011000 flags rw-s (stack)
E/LD:  region  6: va 0x40025000 pa 0x8592e000 size 0x002000 flags rw-- (param)
E/LD:  region  7: va 0x4004d000 pa 0x00001000 size 0x067000 flags r-xs [0]
E/LD:  region  8: va 0x400b4000 pa 0x00068000 size 0x01f000 flags rw-s [0]
E/LD:   [0] bc50d971-d4c9-42c4-82cb-343fb7f37896 @ 0x4004d000
E/LD:  Call stack:
E/LD:   0x4008af50
E/LD:   0x4004dbb4
E/LD:   0x4004e238
E/LD:   0x4006cd5c
E/LD:   0x40086014
E/LD:   0x4004eae4
E/LD:   0x4009109c
E/LD:   0x400861c4
[  201.359311] tpm tpm0: ftpm_tee_tpm_op_send: SUBMIT_COMMAND invoke error: 0xffff3024
[  201.367031] tpm tpm0: tpm_try_transmit: send(): error -53212

tpm_ftpm_tee was built into the kernel, I dropped the rmmod workaround.

If you suspect backporting issues, I need to look into getting upstream 
running again (it does on our board but it's not commonly tested yet due 
to some missing feature called Ethernet).

Jan

-- 
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Competence Center Embedded Linux