Re: [PATCH] tee: make tee_class constant

On Fri, 6 Oct 2023 at 19:30, Greg Kroah-Hartman gregkh@linuxfoundation.org wrote:

Now that the driver core allows for struct class to be in read-only memory, we should make all 'class' structures declared at build time placing them into read-only memory, instead of having to be dynamically allocated at runtime.

Cc: Jens Wiklander jens.wiklander@linaro.org Cc: Sumit Garg sumit.garg@linaro.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org

---

drivers/tee/tee_core.c | 21 +++++++++++---------- 1 file changed, 11 insertions(+), 10 deletions(-)

Apart from nit below, feel free to add:

Reviewed-by: Sumit Garg sumit.garg@linaro.org

diff --git a/drivers/tee/tee_core.c b/drivers/tee/tee_core.c index 0eb342de0b00..5ddfd5d9ac7f 100644 --- a/drivers/tee/tee_core.c +++ b/drivers/tee/tee_core.c @@ -40,7 +40,10 @@ static const uuid_t tee_client_uuid_ns = UUID_INIT(0x58ac9ca0, 0x2086, 0x4683, static DECLARE_BITMAP(dev_mask, TEE_NUM_DEVICES); static DEFINE_SPINLOCK(driver_lock);

-static struct class *tee_class; +static const struct class tee_class = {

•   .name = "tee",
  

+};

static dev_t tee_devt;

struct tee_context *teedev_open(struct tee_device *teedev) @@ -919,7 +922,7 @@ struct tee_device *tee_device_alloc(const struct tee_desc *teedesc, teedesc->flags & TEE_DESC_PRIVILEGED ? "priv" : "", teedev->id - offs);

•   teedev->dev.class = tee_class;
  

•   teedev->dev.class = &tee_class;
    teedev->dev.release = tee_release_device;
    teedev->dev.parent = dev;
  
  

@@ -1112,7 +1115,7 @@ tee_client_open_context(struct tee_context *start, dev = &start->teedev->dev;

    do {

•           dev = class_find_device(tee_class, dev, &match_data, match_dev);
  

•           dev = class_find_device(&tee_class, dev, &match_data, match_dev);
            if (!dev) {
                    ctx = ERR_PTR(-ENOENT);
                    break;
  

@@ -1226,10 +1229,10 @@ static int __init tee_init(void) { int rc;

•   tee_class = class_create("tee");
  

•   if (IS_ERR(tee_class)) {
  

•   rc = class_register(&tee_class);
  

•   if (rc) {
            pr_err("couldn't create class\n");
  

nit: this error message should be updated as well.

-Sumit

•           return PTR_ERR(tee_class);
  

•           return rc;
    }
  
    rc = alloc_chrdev_region(&tee_devt, 0, TEE_NUM_DEVICES, "tee");
  

@@ -1249,8 +1252,7 @@ static int __init tee_init(void) out_unreg_chrdev: unregister_chrdev_region(tee_devt, TEE_NUM_DEVICES); out_unreg_class:

•   class_destroy(tee_class);
  

•   tee_class = NULL;
  

•   class_unregister(&tee_class);
  
    return rc;
  

} @@ -1259,8 +1261,7 @@ static void __exit tee_exit(void) { bus_unregister(&tee_bus_type); unregister_chrdev_region(tee_devt, TEE_NUM_DEVICES);

•   class_destroy(tee_class);
  

•   tee_class = NULL;
  

•   class_unregister(&tee_class);
  

}

subsys_initcall(tee_init);

2.42.0