bus: mhi: core: Fix error handling in mhi_register_controller()

There are a few problems with the error handling in this function.  They
mostly center around the alloc_ordered_workqueue() allocation.
1) If that allocation fails or if the kcalloc() prior to it fails then
it leads to a NULL dereference when we call
destroy_workqueue(mhi_cntrl->hiprio_wq).
2) The error code is not set.
3) The "mhi_cntrl->mhi_cmd" allocation is not freed.

The error handling was slightly confusing and I re-ordered it to be in
the exact mirror/reverse order of how things were allocated.  I changed
the label names to say what the goto does instead of describing where
the goto comes from.

Fixes: 8f7039787687 ("bus: mhi: core: Move to using high priority workqueue")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Loic Poulain <loic.poulain@linaro.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

diff --git a/drivers/bus/mhi/core/init.c b/drivers/bus/mhi/core/init.c
index 96cde9c0034c7092887042663b8c8dd93d2f3ef1..f0697f433c2f1bb8d32ad71ca24148b5a6d3cbfa 100644 (file)
--- a/drivers/bus/mhi/core/init.c
+++ b/drivers/bus/mhi/core/init.c
@@ -871,7 +871,7 @@ int mhi_register_controller(struct mhi_controller *mhi_cntrl,
                                     sizeof(*mhi_cntrl->mhi_cmd), GFP_KERNEL);
        if (!mhi_cntrl->mhi_cmd) {
                ret = -ENOMEM;
-               goto error_alloc_cmd;
+               goto err_free_event;
        }
 
        INIT_LIST_HEAD(&mhi_cntrl->transition_list);
@@ -886,7 +886,8 @@ int mhi_register_controller(struct mhi_controller *mhi_cntrl,
                                ("mhi_hiprio_wq", WQ_MEM_RECLAIM | WQ_HIGHPRI);
        if (!mhi_cntrl->hiprio_wq) {
                dev_err(mhi_cntrl->cntrl_dev, "Failed to allocate workqueue\n");
-               goto error_alloc_cmd;
+               ret = -ENOMEM;
+               goto err_free_cmd;
        }
 
        mhi_cmd = mhi_cntrl->mhi_cmd;
@@ -932,7 +933,7 @@ int mhi_register_controller(struct mhi_controller *mhi_cntrl,
        ret = mhi_read_reg(mhi_cntrl, mhi_cntrl->regs,
                           SOC_HW_VERSION_OFFS, &soc_info);
        if (ret)
-               goto error_alloc_dev;
+               goto err_destroy_wq;
 
        mhi_cntrl->family_number = (soc_info & SOC_HW_VERSION_FAM_NUM_BMSK) >>
                                        SOC_HW_VERSION_FAM_NUM_SHFT;
@@ -946,7 +947,7 @@ int mhi_register_controller(struct mhi_controller *mhi_cntrl,
        mhi_cntrl->index = ida_alloc(&mhi_controller_ida, GFP_KERNEL);
        if (mhi_cntrl->index < 0) {
                ret = mhi_cntrl->index;
-               goto error_ida_alloc;
+               goto err_destroy_wq;
        }
 
        /* Register controller with MHI bus */
@@ -954,7 +955,7 @@ int mhi_register_controller(struct mhi_controller *mhi_cntrl,
        if (IS_ERR(mhi_dev)) {
                dev_err(mhi_cntrl->cntrl_dev, "Failed to allocate MHI device\n");
                ret = PTR_ERR(mhi_dev);
-               goto error_alloc_dev;
+               goto err_ida_free;
        }
 
        mhi_dev->dev_type = MHI_DEVICE_CONTROLLER;
@@ -967,7 +968,7 @@ int mhi_register_controller(struct mhi_controller *mhi_cntrl,
 
        ret = device_add(&mhi_dev->dev);
        if (ret)
-               goto error_add_dev;
+               goto err_release_dev;
 
        mhi_cntrl->mhi_dev = mhi_dev;
 
@@ -975,19 +976,17 @@ int mhi_register_controller(struct mhi_controller *mhi_cntrl,
 
        return 0;
 
-error_add_dev:
+err_release_dev:
        put_device(&mhi_dev->dev);
-
-error_alloc_dev:
+err_ida_free:
        ida_free(&mhi_controller_ida, mhi_cntrl->index);
-
-error_ida_alloc:
+err_destroy_wq:
+       destroy_workqueue(mhi_cntrl->hiprio_wq);
+err_free_cmd:
        kfree(mhi_cntrl->mhi_cmd);
-
-error_alloc_cmd:
-       vfree(mhi_cntrl->mhi_chan);
+err_free_event:
        kfree(mhi_cntrl->mhi_event);
-       destroy_workqueue(mhi_cntrl->hiprio_wq);
+       vfree(mhi_cntrl->mhi_chan);
 
        return ret;
 }