6.15-stable review patch. If anyone has any objections, please let me know.
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From: Jens Wiklander jens.wiklander@linaro.org
commit 312d02adb959ea199372f375ada06e0186f651e4 upstream.
The OP-TEE driver registers the function notif_callback() for FF-A notifications. However, this function is called in an atomic context leading to errors like this when processing asynchronous notifications:
| BUG: sleeping function called from invalid context at kernel/locking/mutex.c:258 | in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 9, name: kworker/0:0 | preempt_count: 1, expected: 0 | RCU nest depth: 0, expected: 0 | CPU: 0 UID: 0 PID: 9 Comm: kworker/0:0 Not tainted 6.14.0-00019-g657536ebe0aa #13 | Hardware name: linux,dummy-virt (DT) | Workqueue: ffa_pcpu_irq_notification notif_pcpu_irq_work_fn | Call trace: | show_stack+0x18/0x24 (C) | dump_stack_lvl+0x78/0x90 | dump_stack+0x18/0x24 | __might_resched+0x114/0x170 | __might_sleep+0x48/0x98 | mutex_lock+0x24/0x80 | optee_get_msg_arg+0x7c/0x21c | simple_call_with_arg+0x50/0xc0 | optee_do_bottom_half+0x14/0x20 | notif_callback+0x3c/0x48 | handle_notif_callbacks+0x9c/0xe0 | notif_get_and_handle+0x40/0x88 | generic_exec_single+0x80/0xc0 | smp_call_function_single+0xfc/0x1a0 | notif_pcpu_irq_work_fn+0x2c/0x38 | process_one_work+0x14c/0x2b4 | worker_thread+0x2e4/0x3e0 | kthread+0x13c/0x210 | ret_from_fork+0x10/0x20
Fix this by adding work queue to process the notification in a non-atomic context.
Fixes: d0476a59de06 ("optee: ffa_abi: add asynchronous notifications") Cc: stable@vger.kernel.org Reviewed-by: Sumit Garg sumit.garg@oss.qualcomm.com Tested-by: Sudeep Holla sudeep.holla@arm.com Link: https://lore.kernel.org/r/20250602120452.2507084-1-jens.wiklander@linaro.org Signed-off-by: Jens Wiklander jens.wiklander@linaro.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/tee/optee/ffa_abi.c | 41 +++++++++++++++++++++++++++++--------- drivers/tee/optee/optee_private.h | 2 + 2 files changed, 34 insertions(+), 9 deletions(-)
--- a/drivers/tee/optee/ffa_abi.c +++ b/drivers/tee/optee/ffa_abi.c @@ -728,12 +728,21 @@ static bool optee_ffa_exchange_caps(stru return true; }
+static void notif_work_fn(struct work_struct *work) +{ + struct optee_ffa *optee_ffa = container_of(work, struct optee_ffa, + notif_work); + struct optee *optee = container_of(optee_ffa, struct optee, ffa); + + optee_do_bottom_half(optee->ctx); +} + static void notif_callback(int notify_id, void *cb_data) { struct optee *optee = cb_data;
if (notify_id == optee->ffa.bottom_half_value) - optee_do_bottom_half(optee->ctx); + queue_work(optee->ffa.notif_wq, &optee->ffa.notif_work); else optee_notif_send(optee, notify_id); } @@ -817,9 +826,11 @@ static void optee_ffa_remove(struct ffa_ struct optee *optee = ffa_dev_get_drvdata(ffa_dev); u32 bottom_half_id = optee->ffa.bottom_half_value;
- if (bottom_half_id != U32_MAX) + if (bottom_half_id != U32_MAX) { ffa_dev->ops->notifier_ops->notify_relinquish(ffa_dev, bottom_half_id); + destroy_workqueue(optee->ffa.notif_wq); + } optee_remove_common(optee);
mutex_destroy(&optee->ffa.mutex); @@ -835,6 +846,13 @@ static int optee_ffa_async_notif_init(st u32 notif_id = 0; int rc;
+ INIT_WORK(&optee->ffa.notif_work, notif_work_fn); + optee->ffa.notif_wq = create_workqueue("optee_notification"); + if (!optee->ffa.notif_wq) { + rc = -EINVAL; + goto err; + } + while (true) { rc = ffa_dev->ops->notifier_ops->notify_request(ffa_dev, is_per_vcpu, @@ -851,19 +869,24 @@ static int optee_ffa_async_notif_init(st * notifications in that case. */ if (rc != -EACCES) - return rc; + goto err_wq; notif_id++; if (notif_id >= OPTEE_FFA_MAX_ASYNC_NOTIF_VALUE) - return rc; + goto err_wq; } optee->ffa.bottom_half_value = notif_id;
rc = enable_async_notif(optee); - if (rc < 0) { - ffa_dev->ops->notifier_ops->notify_relinquish(ffa_dev, - notif_id); - optee->ffa.bottom_half_value = U32_MAX; - } + if (rc < 0) + goto err_rel; + + return 0; +err_rel: + ffa_dev->ops->notifier_ops->notify_relinquish(ffa_dev, notif_id); +err_wq: + destroy_workqueue(optee->ffa.notif_wq); +err: + optee->ffa.bottom_half_value = U32_MAX;
return rc; } --- a/drivers/tee/optee/optee_private.h +++ b/drivers/tee/optee/optee_private.h @@ -165,6 +165,8 @@ struct optee_ffa { /* Serializes access to @global_ids */ struct mutex mutex; struct rhashtable global_ids; + struct workqueue_struct *notif_wq; + struct work_struct notif_work; };
struct optee;