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

From: Sumit Garg
Date: Wed Jun 07 2023 - 11:15:08 EST

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@xxxxxxxxxxx>
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@xxxxxxxxxx>
---
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,
--
2.34.1