On Tue Jun 20, 2023 at 5:46 PM EEST, Greg Kroah-Hartman wrote:
> From: Ivan Orlov <ivan.orlov0322@xxxxxxxxx>
>
> Now that the driver core allows for struct class to be in read-only
> memory, making all 'class' structures to be declared at build time
> placing them into read-only memory, instead of having to be dynamically
> allocated at load time.
>
> Cc: Peter Huewe <peterhuewe@xxxxxx>
> Cc: Jarkko Sakkinen <jarkko@xxxxxxxxxx>
> Cc: Jason Gunthorpe <jgg@xxxxxxxx>
> Cc: linux-integrity@xxxxxxxxxxxxxxx
> Suggested-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> Signed-off-by: Ivan Orlov <ivan.orlov0322@xxxxxxxxx>
> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> ---
> drivers/char/tpm/tpm-chip.c | 11 ++++++++---
> drivers/char/tpm/tpm-interface.c | 21 +++++++++------------
> drivers/char/tpm/tpm.h | 4 ++--
> drivers/char/tpm/tpm2-space.c | 2 +-
> 4 files changed, 20 insertions(+), 18 deletions(-)
>
> diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c
> index cd48033b804a..7c028f0b9d38 100644
> --- a/drivers/char/tpm/tpm-chip.c
> +++ b/drivers/char/tpm/tpm-chip.c
> @@ -28,8 +28,13 @@
> DEFINE_IDR(dev_nums_idr);
> static DEFINE_MUTEX(idr_lock);
>
> -struct class *tpm_class;
> -struct class *tpmrm_class;
> +const struct class tpm_class = {
> + .name = "tpm",
> + .shutdown_pre = tpm_class_shutdown,
> +};
> +const struct class tpmrm_class = {
> + .name = "tmprm",
> +};
> dev_t tpm_devt;
>
> static int tpm_request_locality(struct tpm_chip *chip)
> @@ -336,7 +341,7 @@ struct tpm_chip *tpm_chip_alloc(struct device *pdev,
>
> device_initialize(&chip->dev);
>
> - chip->dev.class = tpm_class;
> + chip->dev.class = &tpm_class;
> chip->dev.release = tpm_dev_release;
> chip->dev.parent = pdev;
> chip->dev.groups = chip->groups;
> diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c
> index 586ca10b0d72..66b16d26eecc 100644
> --- a/drivers/char/tpm/tpm-interface.c
> +++ b/drivers/char/tpm/tpm-interface.c
> @@ -476,18 +476,15 @@ static int __init tpm_init(void)
> {
> int rc;
>
> - tpm_class = class_create("tpm");
> - if (IS_ERR(tpm_class)) {
> + rc = class_register(&tpm_class);
> + if (rc) {
> pr_err("couldn't create tpm class\n");
> - return PTR_ERR(tpm_class);
> + return rc;
> }
>
> - tpm_class->shutdown_pre = tpm_class_shutdown;
> -
> - tpmrm_class = class_create("tpmrm");
> - if (IS_ERR(tpmrm_class)) {
> + rc = class_register(&tpmrm_class);
> + if (rc) {
> pr_err("couldn't create tpmrm class\n");
> - rc = PTR_ERR(tpmrm_class);
> goto out_destroy_tpm_class;
> }
>
> @@ -508,9 +505,9 @@ static int __init tpm_init(void)
> out_unreg_chrdev:
> unregister_chrdev_region(tpm_devt, 2 * TPM_NUM_DEVICES);
> out_destroy_tpmrm_class:
> - class_destroy(tpmrm_class);
> + class_unregister(&tpmrm_class);
> out_destroy_tpm_class:
> - class_destroy(tpm_class);
> + class_unregister(&tpm_class);
>
> return rc;
> }
> @@ -518,8 +515,8 @@ static int __init tpm_init(void)
> static void __exit tpm_exit(void)
> {
> idr_destroy(&dev_nums_idr);
> - class_destroy(tpm_class);
> - class_destroy(tpmrm_class);
> + class_unregister(&tpm_class);
> + class_unregister(&tpmrm_class);
> unregister_chrdev_region(tpm_devt, 2*TPM_NUM_DEVICES);
> tpm_dev_common_exit();
> }
> diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h
> index 460bb85dd142..61445f1dc46d 100644
> --- a/drivers/char/tpm/tpm.h
> +++ b/drivers/char/tpm/tpm.h
> @@ -230,8 +230,8 @@ enum tpm2_pt_props {
> * compiler warnings about stack frame size. */
> #define TPM_MAX_RNG_DATA 128
>
> -extern struct class *tpm_class;
> -extern struct class *tpmrm_class;
> +extern const struct class tpm_class;
> +extern const struct class tpmrm_class;
> extern dev_t tpm_devt;
> extern const struct file_operations tpm_fops;
> extern const struct file_operations tpmrm_fops;
> diff --git a/drivers/char/tpm/tpm2-space.c b/drivers/char/tpm/tpm2-space.c
> index ffb35f0154c1..363afdd4d1d3 100644
> --- a/drivers/char/tpm/tpm2-space.c
> +++ b/drivers/char/tpm/tpm2-space.c
> @@ -606,7 +606,7 @@ int tpm_devs_add(struct tpm_chip *chip)
>
> device_initialize(&chip->devs);
> chip->devs.parent = chip->dev.parent;
> - chip->devs.class = tpmrm_class;
> + chip->devs.class = &tpmrm_class;
>
> /*
> * Get extra reference on main device to hold on behalf of devs.
> --
> 2.41.0
Acked-by: Jarkko Sakkinen <jarkko@xxxxxxxxxx>
BR, Jarkko
