Hi Jens, On Fri, 5 Apr 2024 at 17:23, Jens Wiklander <jens.wiklander@xxxxxxxxxx> wrote: > > Adds support in the OP-TEE drivers (both SMC and FF-A ABIs) to probe and > use an RPMB device via the RPBM subsystem instead of passing the RPMB s/RPBM/RPMB/ > frames via tee-supplicant in user space. A fallback mechanism is kept to > route RPMB frames via tee-supplicant if the RPMB subsystem isn't > available. > > The OP-TEE RPC ABI is extended to support iterating over all RPMB > devices until one is found with the expected RPMB key already > programmed. > > Signed-off-by: Jens Wiklander <jens.wiklander@xxxxxxxxxx> > --- > drivers/tee/optee/core.c | 30 ++++ > drivers/tee/optee/device.c | 7 + > drivers/tee/optee/ffa_abi.c | 8 + > drivers/tee/optee/optee_private.h | 21 ++- > drivers/tee/optee/optee_rpc_cmd.h | 35 +++++ > drivers/tee/optee/rpc.c | 233 ++++++++++++++++++++++++++++++ > drivers/tee/optee/smc_abi.c | 7 + > 7 files changed, 340 insertions(+), 1 deletion(-) > > diff --git a/drivers/tee/optee/core.c b/drivers/tee/optee/core.c > index 3aed554bc8d8..082691c10a90 100644 > --- a/drivers/tee/optee/core.c > +++ b/drivers/tee/optee/core.c > @@ -11,6 +11,7 @@ > #include <linux/io.h> > #include <linux/mm.h> > #include <linux/module.h> > +#include <linux/rpmb.h> > #include <linux/slab.h> > #include <linux/string.h> > #include <linux/tee_drv.h> > @@ -80,6 +81,31 @@ void optee_pool_op_free_helper(struct tee_shm_pool *pool, struct tee_shm *shm, > shm->pages = NULL; > } > > +void optee_bus_scan_rpmb(struct work_struct *work) > +{ > + struct optee *optee = container_of(work, struct optee, > + rpmb_scan_bus_work); > + int ret; > + > + if (!optee->rpmb_scan_bus_done) { > + ret = optee_enumerate_devices(PTA_CMD_GET_DEVICES_RPMB); > + optee->rpmb_scan_bus_done = !ret; > + if (ret && ret != -ENODEV) > + pr_info("Scanning for RPMB device: ret %d\n", ret); > + } > +} > + > +int optee_rpmb_intf_rdev(struct notifier_block *intf, unsigned long action, > + void *data) > +{ > + struct optee *optee = container_of(intf, struct optee, rpmb_intf); > + > + if (action == RPMB_NOTIFY_ADD_DEVICE) > + schedule_work(&optee->rpmb_scan_bus_work); > + > + return 0; > +} > + > static void optee_bus_scan(struct work_struct *work) > { > WARN_ON(optee_enumerate_devices(PTA_CMD_GET_DEVICES_SUPP)); > @@ -161,6 +187,8 @@ void optee_release_supp(struct tee_context *ctx) > > void optee_remove_common(struct optee *optee) > { > + rpmb_interface_unregister(&optee->rpmb_intf); > + cancel_work_sync(&optee->rpmb_scan_bus_work); > /* Unregister OP-TEE specific client devices on TEE bus */ > optee_unregister_devices(); > > @@ -177,6 +205,8 @@ void optee_remove_common(struct optee *optee) > tee_shm_pool_free(optee->pool); > optee_supp_uninit(&optee->supp); > mutex_destroy(&optee->call_queue.mutex); > + rpmb_dev_put(optee->rpmb_dev); > + mutex_destroy(&optee->rpmb_dev_mutex); > } > > static int smc_abi_rc; > diff --git a/drivers/tee/optee/device.c b/drivers/tee/optee/device.c > index 4b1092127694..4274876857c8 100644 > --- a/drivers/tee/optee/device.c > +++ b/drivers/tee/optee/device.c > @@ -43,6 +43,13 @@ static int get_devices(struct tee_context *ctx, u32 session, > ret = tee_client_invoke_func(ctx, &inv_arg, param); > if ((ret < 0) || ((inv_arg.ret != TEEC_SUCCESS) && > (inv_arg.ret != TEEC_ERROR_SHORT_BUFFER))) { > + /* > + * TEE_ERROR_STORAGE_NOT_AVAILABLE is returned when getting > + * the list of device TAs that depends on RPMB but a usable > + * RPMB device isn't found. > + */ > + if (inv_arg.ret == TEE_ERROR_STORAGE_NOT_AVAILABLE) > + return -ENODEV; > pr_err("PTA_CMD_GET_DEVICES invoke function err: %x\n", > inv_arg.ret); > return -EINVAL; > diff --git a/drivers/tee/optee/ffa_abi.c b/drivers/tee/optee/ffa_abi.c > index ecb5eb079408..a8dfdb30b4e8 100644 > --- a/drivers/tee/optee/ffa_abi.c > +++ b/drivers/tee/optee/ffa_abi.c > @@ -7,6 +7,7 @@ > > #include <linux/arm_ffa.h> > #include <linux/errno.h> > +#include <linux/rpmb.h> > #include <linux/scatterlist.h> > #include <linux/sched.h> > #include <linux/slab.h> > @@ -934,6 +935,7 @@ static int optee_ffa_probe(struct ffa_device *ffa_dev) > optee_cq_init(&optee->call_queue, 0); > optee_supp_init(&optee->supp); > optee_shm_arg_cache_init(optee, arg_cache_flags); > + mutex_init(&optee->rpmb_dev_mutex); > ffa_dev_set_drvdata(ffa_dev, optee); > ctx = teedev_open(optee->teedev); > if (IS_ERR(ctx)) { > @@ -955,6 +957,9 @@ static int optee_ffa_probe(struct ffa_device *ffa_dev) > if (rc) > goto err_unregister_devices; > > + INIT_WORK(&optee->rpmb_scan_bus_work, optee_bus_scan_rpmb); > + optee->rpmb_intf.notifier_call = optee_rpmb_intf_rdev; > + rpmb_interface_register(&optee->rpmb_intf); > pr_info("initialized driver\n"); > return 0; > > @@ -968,6 +973,9 @@ static int optee_ffa_probe(struct ffa_device *ffa_dev) > teedev_close_context(ctx); > err_rhashtable_free: > rhashtable_free_and_destroy(&optee->ffa.global_ids, rh_free_fn, NULL); > + rpmb_dev_put(optee->rpmb_dev); > + mutex_destroy(&optee->rpmb_dev_mutex); > + rpmb_interface_unregister(&optee->rpmb_intf); > optee_supp_uninit(&optee->supp); > mutex_destroy(&optee->call_queue.mutex); > mutex_destroy(&optee->ffa.mutex); > diff --git a/drivers/tee/optee/optee_private.h b/drivers/tee/optee/optee_private.h > index 7a5243c78b55..ae72f3dda1d2 100644 > --- a/drivers/tee/optee/optee_private.h > +++ b/drivers/tee/optee/optee_private.h > @@ -8,6 +8,7 @@ > > #include <linux/arm-smccc.h> > #include <linux/rhashtable.h> > +#include <linux/rpmb.h> > #include <linux/semaphore.h> > #include <linux/tee_drv.h> > #include <linux/types.h> > @@ -20,11 +21,13 @@ > /* Some Global Platform error codes used in this driver */ > #define TEEC_SUCCESS 0x00000000 > #define TEEC_ERROR_BAD_PARAMETERS 0xFFFF0006 > +#define TEEC_ERROR_ITEM_NOT_FOUND 0xFFFF0008 > #define TEEC_ERROR_NOT_SUPPORTED 0xFFFF000A > #define TEEC_ERROR_COMMUNICATION 0xFFFF000E > #define TEEC_ERROR_OUT_OF_MEMORY 0xFFFF000C > #define TEEC_ERROR_BUSY 0xFFFF000D > #define TEEC_ERROR_SHORT_BUFFER 0xFFFF0010 > +#define TEE_ERROR_STORAGE_NOT_AVAILABLE 0xF0100003 > > #define TEEC_ORIGIN_COMMS 0x00000002 > > @@ -197,6 +200,12 @@ struct optee_ops { > * @notif: notification synchronization struct > * @supp: supplicant synchronization struct for RPC to supplicant > * @pool: shared memory pool > + * @mutex: mutex protecting @rpmb_dev > + * @rpmb_dev: current RPMB device or NULL > + * @rpmb_scan_bus_done flag if device registation of RPMB dependent devices > + * was already done > + * @rpmb_scan_bus_work workq to for an RPMB device and to scan optee bus > + * and register RPMB dependent optee drivers > * @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_work workq to scan optee bus and register optee drivers > @@ -215,9 +224,15 @@ struct optee { > struct optee_notif notif; > struct optee_supp supp; > struct tee_shm_pool *pool; > + /* Protects rpmb_dev pointer */ > + struct mutex rpmb_dev_mutex; > + struct rpmb_dev *rpmb_dev; > + struct notifier_block rpmb_intf; > unsigned int rpc_param_count; > - bool scan_bus_done; > + bool scan_bus_done; > + bool rpmb_scan_bus_done; > struct work_struct scan_bus_work; > + struct work_struct rpmb_scan_bus_work; > }; > > struct optee_session { > @@ -280,8 +295,12 @@ int optee_cancel_req(struct tee_context *ctx, u32 cancel_id, u32 session); > > #define PTA_CMD_GET_DEVICES 0x0 > #define PTA_CMD_GET_DEVICES_SUPP 0x1 > +#define PTA_CMD_GET_DEVICES_RPMB 0x2 > int optee_enumerate_devices(u32 func); > void optee_unregister_devices(void); > +void optee_bus_scan_rpmb(struct work_struct *work); > +int optee_rpmb_intf_rdev(struct notifier_block *intf, unsigned long action, > + void *data); > > int optee_pool_op_alloc_helper(struct tee_shm_pool *pool, struct tee_shm *shm, > size_t size, size_t align, > diff --git a/drivers/tee/optee/optee_rpc_cmd.h b/drivers/tee/optee/optee_rpc_cmd.h > index f3f06e0994a7..f351a8ac69fc 100644 > --- a/drivers/tee/optee/optee_rpc_cmd.h > +++ b/drivers/tee/optee/optee_rpc_cmd.h > @@ -16,6 +16,14 @@ > * and sends responses. > */ > > +/* > + * Replay Protected Memory Block access > + * > + * [in] memref[0] Frames to device > + * [out] memref[1] Frames from device > + */ > +#define OPTEE_RPC_CMD_RPMB 1 > + > /* > * Get time > * > @@ -103,4 +111,31 @@ > /* I2C master control flags */ > #define OPTEE_RPC_I2C_FLAGS_TEN_BIT BIT(0) > > +/* > + * Reset RPMB probing > + * > + * Releases an eventually already used RPMB devices and starts over searching > + * for RPMB devices. Returns the kind of shared memory to use in subsequent > + * OPTEE_RPC_CMD_RPMB_PROBE_NEXT and OPTEE_RPC_CMD_RPMB calls. > + * > + * [out] value[0].a OPTEE_RPC_SHM_TYPE_*, the parameter for > + * OPTEE_RPC_CMD_SHM_ALLOC > + */ > +#define OPTEE_RPC_CMD_RPMB_PROBE_RESET 22 > + AFAICS from [1], this RPMB reset probing is only used to check if the kernel supports RPMB probing or not. I suppose that should be detected via a single RPC call like: OPTEE_RPC_CMD_RPMB_PROBE. Other than that the shared memory allocation type can be used as THREAD_SHM_TYPE_KERNEL_PRIVATE if OPTEE_RPC_CMD_RPMB_PROBE works otherwise THREAD_SHM_TYPE_APPLICATION can be used for legacy RPMB init via tee-supplicant. Is there any other specific scenario I am missing which requires an explicit RPMB probe reset call? [1] https://github.com/jenswi-linaro/optee_os/commit/50ed7324411e3bdf7dba702d75eb0dbedda1c5cd -Sumit > +/* > + * Probe next RPMB device > + * > + * [out] value[0].a Type of RPMB device, OPTEE_RPC_RPMB_* > + * [out] value[0].b EXT CSD-slice 168 "RPMB Size" > + * [out] value[0].c EXT CSD-slice 222 "Reliable Write Sector Count" > + * [out] memref[1] Buffer with the raw CID > + */ > +#define OPTEE_RPC_CMD_RPMB_PROBE_NEXT 23 > + > +/* Type of RPMB device */ > +#define OPTEE_RPC_RPMB_EMMC 0 > +#define OPTEE_RPC_RPMB_UFS 1 > +#define OPTEE_RPC_RPMB_NVME 2 > + > #endif /*__OPTEE_RPC_CMD_H*/ > diff --git a/drivers/tee/optee/rpc.c b/drivers/tee/optee/rpc.c > index e69bc6380683..e211c1c94984 100644 > --- a/drivers/tee/optee/rpc.c > +++ b/drivers/tee/optee/rpc.c > @@ -7,6 +7,7 @@ > > #include <linux/delay.h> > #include <linux/i2c.h> > +#include <linux/rpmb.h> > #include <linux/slab.h> > #include <linux/tee_drv.h> > #include "optee_private.h" > @@ -255,6 +256,229 @@ void optee_rpc_cmd_free_suppl(struct tee_context *ctx, struct tee_shm *shm) > optee_supp_thrd_req(ctx, OPTEE_RPC_CMD_SHM_FREE, 1, ¶m); > } > > +static void handle_rpc_func_rpmb_probe_reset(struct tee_context *ctx, > + struct optee *optee, > + struct optee_msg_arg *arg) > +{ > + struct tee_param params[1]; > + > + if (!IS_ENABLED(CONFIG_RPMB)) { > + handle_rpc_supp_cmd(ctx, optee, arg); > + return; > + } > + > + if (arg->num_params != ARRAY_SIZE(params) || > + optee->ops->from_msg_param(optee, params, arg->num_params, > + arg->params) || > + params[0].attr != TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_OUTPUT) { > + arg->ret = TEEC_ERROR_BAD_PARAMETERS; > + return; > + } > + > + params[0].u.value.a = OPTEE_RPC_SHM_TYPE_KERNEL; > + params[0].u.value.b = 0; > + params[0].u.value.c = 0; > + if (optee->ops->to_msg_param(optee, arg->params, > + arg->num_params, params)) { > + arg->ret = TEEC_ERROR_BAD_PARAMETERS; > + return; > + } > + > + mutex_lock(&optee->rpmb_dev_mutex); > + rpmb_dev_put(optee->rpmb_dev); > + optee->rpmb_dev = NULL; > + mutex_unlock(&optee->rpmb_dev_mutex); > + > + arg->ret = TEEC_SUCCESS; > +} > + > +static int rpmb_type_to_rpc_type(enum rpmb_type rtype) > +{ > + switch (rtype) { > + case RPMB_TYPE_EMMC: > + return OPTEE_RPC_RPMB_EMMC; > + case RPMB_TYPE_UFS: > + return OPTEE_RPC_RPMB_UFS; > + case RPMB_TYPE_NVME: > + return OPTEE_RPC_RPMB_NVME; > + default: > + return -1; > + } > +} > + > +static int rpc_rpmb_match(struct rpmb_dev *rdev, const void *data) > +{ > + return rpmb_type_to_rpc_type(rdev->descr.type) >= 0; > +} > + > +static void handle_rpc_func_rpmb_probe_next(struct tee_context *ctx, > + struct optee *optee, > + struct optee_msg_arg *arg) > +{ > + struct rpmb_dev *rdev; > + struct tee_param params[2]; > + void *buf; > + > + if (!IS_REACHABLE(CONFIG_RPMB)) { > + handle_rpc_supp_cmd(ctx, optee, arg); > + return; > + } > + > + if (arg->num_params != ARRAY_SIZE(params) || > + optee->ops->from_msg_param(optee, params, arg->num_params, > + arg->params) || > + params[0].attr != TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_OUTPUT || > + params[1].attr != TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT) { > + arg->ret = TEEC_ERROR_BAD_PARAMETERS; > + return; > + } > + buf = tee_shm_get_va(params[1].u.memref.shm, > + params[1].u.memref.shm_offs); > + if (!buf) { > + arg->ret = TEEC_ERROR_BAD_PARAMETERS; > + return; > + } > + > + mutex_lock(&optee->rpmb_dev_mutex); > + rdev = rpmb_dev_find_device(NULL, optee->rpmb_dev, rpc_rpmb_match); > + rpmb_dev_put(optee->rpmb_dev); > + optee->rpmb_dev = rdev; > + mutex_unlock(&optee->rpmb_dev_mutex); > + > + if (!rdev) { > + arg->ret = TEEC_ERROR_ITEM_NOT_FOUND; > + return; > + } > + > + if (params[1].u.memref.size < rdev->descr.dev_id_len) { > + arg->ret = TEEC_ERROR_SHORT_BUFFER; > + return; > + } > + memcpy(buf, rdev->descr.dev_id, rdev->descr.dev_id_len); > + params[1].u.memref.size = rdev->descr.dev_id_len; > + params[0].u.value.a = rpmb_type_to_rpc_type(rdev->descr.type); > + params[0].u.value.b = rdev->descr.capacity; > + params[0].u.value.c = rdev->descr.reliable_wr_count; > + if (optee->ops->to_msg_param(optee, arg->params, > + arg->num_params, params)) { > + arg->ret = TEEC_ERROR_BAD_PARAMETERS; > + return; > + } > + > + arg->ret = TEEC_SUCCESS; > +} > + > +/* Request */ > +struct rpmb_req { > + u16 cmd; > +#define RPMB_CMD_DATA_REQ 0x00 > +#define RPMB_CMD_GET_DEV_INFO 0x01 > + u16 dev_id; > + u16 block_count; > + /* Optional data frames (rpmb_data_frame) follow */ > +}; > + > +#define RPMB_REQ_DATA(req) ((void *)((struct rpmb_req *)(req) + 1)) > + > +#define RPMB_CID_SZ 16 > + > +/* Response to device info request */ > +struct rpmb_dev_info { > + u8 cid[RPMB_CID_SZ]; > + u8 rpmb_size_mult; /* EXT CSD-slice 168: RPMB Size */ > + u8 rel_wr_sec_c; /* EXT CSD-slice 222: Reliable Write Sector */ > + /* Count */ > + u8 ret_code; > +#define RPMB_CMD_GET_DEV_INFO_RET_OK 0x00 > +#define RPMB_CMD_GET_DEV_INFO_RET_ERROR 0x01 > +}; > + > +static int get_dev_info(struct rpmb_dev *rdev, void *rsp, size_t rsp_size) > +{ > + struct rpmb_dev_info *dev_info; > + > + if (rsp_size != sizeof(*dev_info)) > + return TEEC_ERROR_BAD_PARAMETERS; > + > + dev_info = rsp; > + memcpy(dev_info->cid, rdev->descr.dev_id, sizeof(dev_info->cid)); > + dev_info->rpmb_size_mult = rdev->descr.capacity; > + dev_info->rel_wr_sec_c = rdev->descr.reliable_wr_count; > + dev_info->ret_code = RPMB_CMD_GET_DEV_INFO_RET_OK; > + > + return TEEC_SUCCESS; > +} > + > +/* > + * req is one struct rpmb_req followed by one or more struct rpmb_data_frame > + * rsp is either one struct rpmb_dev_info or one or more struct rpmb_data_frame > + */ > +static u32 rpmb_process_request(struct optee *optee, struct rpmb_dev *rdev, > + void *req, size_t req_size, > + void *rsp, size_t rsp_size) > +{ > + struct rpmb_req *sreq = req; > + int rc; > + > + if (req_size < sizeof(*sreq)) > + return TEEC_ERROR_BAD_PARAMETERS; > + > + switch (sreq->cmd) { > + case RPMB_CMD_DATA_REQ: > + rc = rpmb_route_frames(rdev, RPMB_REQ_DATA(req), > + req_size - sizeof(struct rpmb_req), > + rsp, rsp_size); > + if (rc) > + return TEEC_ERROR_BAD_PARAMETERS; > + return TEEC_SUCCESS; > + case RPMB_CMD_GET_DEV_INFO: > + return get_dev_info(rdev, rsp, rsp_size); > + default: > + return TEEC_ERROR_BAD_PARAMETERS; > + } > +} > + > +static void handle_rpc_func_rpmb(struct tee_context *ctx, struct optee *optee, > + struct optee_msg_arg *arg) > +{ > + struct tee_param params[2]; > + struct rpmb_dev *rdev; > + void *p0, *p1; > + > + mutex_lock(&optee->rpmb_dev_mutex); > + rdev = rpmb_dev_get(optee->rpmb_dev); > + mutex_unlock(&optee->rpmb_dev_mutex); > + if (!rdev) { > + handle_rpc_supp_cmd(ctx, optee, arg); > + return; > + } > + > + if (arg->num_params != ARRAY_SIZE(params) || > + optee->ops->from_msg_param(optee, params, arg->num_params, > + arg->params) || > + params[0].attr != TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT || > + params[1].attr != TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT) { > + arg->ret = TEEC_ERROR_BAD_PARAMETERS; > + goto out; > + } > + > + p0 = tee_shm_get_va(params[0].u.memref.shm, > + params[0].u.memref.shm_offs); > + p1 = tee_shm_get_va(params[1].u.memref.shm, > + params[1].u.memref.shm_offs); > + arg->ret = rpmb_process_request(optee, rdev, p0, > + params[0].u.memref.size, > + p1, params[1].u.memref.size); > + if (arg->ret) > + goto out; > + > + if (optee->ops->to_msg_param(optee, arg->params, > + arg->num_params, params)) > + arg->ret = TEEC_ERROR_BAD_PARAMETERS; > +out: > + rpmb_dev_put(rdev); > +} > + > void optee_rpc_cmd(struct tee_context *ctx, struct optee *optee, > struct optee_msg_arg *arg) > { > @@ -271,6 +495,15 @@ void optee_rpc_cmd(struct tee_context *ctx, struct optee *optee, > case OPTEE_RPC_CMD_I2C_TRANSFER: > handle_rpc_func_cmd_i2c_transfer(ctx, arg); > break; > + case OPTEE_RPC_CMD_RPMB_PROBE_RESET: > + handle_rpc_func_rpmb_probe_reset(ctx, optee, arg); > + break; > + case OPTEE_RPC_CMD_RPMB_PROBE_NEXT: > + handle_rpc_func_rpmb_probe_next(ctx, optee, arg); > + break; > + case OPTEE_RPC_CMD_RPMB: > + handle_rpc_func_rpmb(ctx, optee, arg); > + break; > default: > handle_rpc_supp_cmd(ctx, optee, arg); > } > diff --git a/drivers/tee/optee/smc_abi.c b/drivers/tee/optee/smc_abi.c > index a37f87087e5c..c23bcf35c8cb 100644 > --- a/drivers/tee/optee/smc_abi.c > +++ b/drivers/tee/optee/smc_abi.c > @@ -20,6 +20,7 @@ > #include <linux/of_irq.h> > #include <linux/of_platform.h> > #include <linux/platform_device.h> > +#include <linux/rpmb.h> > #include <linux/sched.h> > #include <linux/slab.h> > #include <linux/string.h> > @@ -1715,6 +1716,7 @@ static int optee_probe(struct platform_device *pdev) > optee->smc.memremaped_shm = memremaped_shm; > optee->pool = pool; > optee_shm_arg_cache_init(optee, arg_cache_flags); > + mutex_init(&optee->rpmb_dev_mutex); > > platform_set_drvdata(pdev, optee); > ctx = teedev_open(optee->teedev); > @@ -1769,6 +1771,9 @@ static int optee_probe(struct platform_device *pdev) > if (rc) > goto err_disable_shm_cache; > > + INIT_WORK(&optee->rpmb_scan_bus_work, optee_bus_scan_rpmb); > + optee->rpmb_intf.notifier_call = optee_rpmb_intf_rdev; > + rpmb_interface_register(&optee->rpmb_intf); > pr_info("initialized driver\n"); > return 0; > > @@ -1782,6 +1787,8 @@ static int optee_probe(struct platform_device *pdev) > err_close_ctx: > teedev_close_context(ctx); > err_supp_uninit: > + rpmb_dev_put(optee->rpmb_dev); > + mutex_destroy(&optee->rpmb_dev_mutex); > optee_shm_arg_cache_uninit(optee); > optee_supp_uninit(&optee->supp); > mutex_destroy(&optee->call_queue.mutex); > -- > 2.34.1 >