From: Ira Weiny <ira.weiny@xxxxxxxxx> Work item initialization needs to be done with either INIT_WORK_ONSTACK() or INIT_WORK() depending on how the work item is allocated. The callers of pci_doe_submit_task() allocate struct pci_doe_task on the stack and pci_doe_submit_task() incorrectly used INIT_WORK(). Jonathan suggested creating doe task allocation macros such as DECLARE_CDAT_DOE_TASK_ONSTACK().[1] The issue with this is the work function is not known to the callers and must be initialized correctly. A follow up suggestion was to have an internal 'pci_doe_work' item allocated by pci_doe_submit_task().[2] This requires an allocation which could restrict the context where tasks are used. Another idea was to have an intermediate step to initialize the task struct with a new call.[3] This added a lot of complexity. Lukas pointed out that object_is_on_stack() is available to detect this automatically. Use object_is_on_stack() to determine the correct init work function to call. [1] https://lore.kernel.org/linux-cxl/20221014151045.24781-1-Jonathan.Cameron@xxxxxxxxxx/T/#m88a7f50dcce52f30c8bf5c3dcc06fa9843b54a2d [2] https://lore.kernel.org/linux-cxl/20221014151045.24781-1-Jonathan.Cameron@xxxxxxxxxx/T/#m63c636c5135f304480370924f4d03c00357be667 [3] https://lore.kernel.org/all/20221115011943.1051039-1-ira.weiny@xxxxxxxxx/ Cc: Bjorn Helgaas <helgaas@xxxxxxxxxx> Cc: Dan Williams <dan.j.williams@xxxxxxxxx> Reported-by: Gregory Price <gregory.price@xxxxxxxxxxxx> Reported-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx> Suggested-by: Lukas Wunner <lukas@xxxxxxxxx> Signed-off-by: Ira Weiny <ira.weiny@xxxxxxxxx> --- Changes from V1 Update oneliner Use object_is_on_stack() to make this a simple fix --- drivers/pci/doe.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/pci/doe.c b/drivers/pci/doe.c index e402f05068a5..42de517022d9 100644 --- a/drivers/pci/doe.c +++ b/drivers/pci/doe.c @@ -19,6 +19,7 @@ #include <linux/pci.h> #include <linux/pci-doe.h> #include <linux/workqueue.h> +#include <linux/sched/task_stack.h> #define PCI_DOE_PROTOCOL_DISCOVERY 0 @@ -529,7 +530,10 @@ int pci_doe_submit_task(struct pci_doe_mb *doe_mb, struct pci_doe_task *task) return -EIO; task->doe_mb = doe_mb; - INIT_WORK(&task->work, doe_statemachine_work); + if (object_is_on_stack(&task->work)) + INIT_WORK_ONSTACK(&task->work, doe_statemachine_work); + else + INIT_WORK(&task->work, doe_statemachine_work); queue_work(doe_mb->work_queue, &task->work); return 0; } base-commit: 30a0b95b1335e12efef89dd78518ed3e4a71a763 prerequisite-patch-id: dfea657e07f37aa9d7c3d477d68b07f64fe78721 prerequisite-patch-id: e27264e76e637214ee50cdab0e5854b223d44b4e -- 2.37.2
