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author | Sergey Ryazanov <ryazanov.s.a@gmail.com> | 2021-12-07 12:21:40 +0300 |
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committer | Jakub Kicinski <kuba@kernel.org> | 2021-12-08 17:58:59 -0800 |
commit | 283e6f5a8166f075eba78da6b867d76cc5d47e77 (patch) | |
tree | ee7c7a9be96d421f0a3d5dd7bf55a63bed20c25a /drivers/net/wwan/wwan_core.c | |
parent | cf90098dbb1f784661354ff8f7ca293e1ff8153b (diff) | |
download | linux-283e6f5a8166f075eba78da6b867d76cc5d47e77.tar.bz2 |
net: wwan: make debugfs optional
Debugfs interface is optional for the regular modem use. Some distros
and users will want to disable this feature for security or kernel
size reasons. So add a configuration option that allows to completely
disable the debugfs interface of the WWAN devices.
A primary considered use case for this option was embedded firmwares.
For example, in OpenWrt, you can not completely disable debugfs, as a
lot of wireless stuff can only be configured and monitored with the
debugfs knobs. At the same time, reducing the size of a kernel and
modules is an essential task in the world of embedded software.
Disabling the WWAN and IOSM debugfs interfaces allows us to save 50K
(x86-64 build) of space for module storage. Not much, but already
considerable when you only have 16MB of storage.
So it is hard to just disable whole debugfs. Users need some fine
grained set of options to control which debugfs interface is important
and should be available and which is not.
The new configuration symbol is enabled by default and is hidden under
the EXPERT option. So a regular user would not be bothered by another
one configuration question. While an embedded distro maintainer will be
able to a little more reduce the final image size.
Signed-off-by: Sergey Ryazanov <ryazanov.s.a@gmail.com>
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Reviewed-by: Loic Poulain <loic.poulain@linaro.org>
Acked-by: M Chetan Kumar <m.chetan.kumar@intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'drivers/net/wwan/wwan_core.c')
-rw-r--r-- | drivers/net/wwan/wwan_core.c | 17 |
1 files changed, 13 insertions, 4 deletions
diff --git a/drivers/net/wwan/wwan_core.c b/drivers/net/wwan/wwan_core.c index 5bf62dc35ac7..1508dc2a497b 100644 --- a/drivers/net/wwan/wwan_core.c +++ b/drivers/net/wwan/wwan_core.c @@ -50,7 +50,9 @@ struct wwan_device { atomic_t port_id; const struct wwan_ops *ops; void *ops_ctxt; +#ifdef CONFIG_WWAN_DEBUGFS struct dentry *debugfs_dir; +#endif }; /** @@ -146,6 +148,7 @@ static struct wwan_device *wwan_dev_get_by_name(const char *name) return to_wwan_dev(dev); } +#ifdef CONFIG_WWAN_DEBUGFS struct dentry *wwan_get_debugfs_dir(struct device *parent) { struct wwan_device *wwandev; @@ -157,6 +160,7 @@ struct dentry *wwan_get_debugfs_dir(struct device *parent) return wwandev->debugfs_dir; } EXPORT_SYMBOL_GPL(wwan_get_debugfs_dir); +#endif /* This function allocates and registers a new WWAN device OR if a WWAN device * already exist for the given parent, it gets a reference and return it. @@ -166,7 +170,6 @@ EXPORT_SYMBOL_GPL(wwan_get_debugfs_dir); static struct wwan_device *wwan_create_dev(struct device *parent) { struct wwan_device *wwandev; - const char *wwandev_name; int err, id; /* The 'find-alloc-register' operation must be protected against @@ -206,9 +209,11 @@ static struct wwan_device *wwan_create_dev(struct device *parent) goto done_unlock; } - wwandev_name = kobject_name(&wwandev->dev.kobj); - wwandev->debugfs_dir = debugfs_create_dir(wwandev_name, - wwan_debugfs_dir); +#ifdef CONFIG_WWAN_DEBUGFS + wwandev->debugfs_dir = + debugfs_create_dir(kobject_name(&wwandev->dev.kobj), + wwan_debugfs_dir); +#endif done_unlock: mutex_unlock(&wwan_register_lock); @@ -240,7 +245,9 @@ static void wwan_remove_dev(struct wwan_device *wwandev) ret = device_for_each_child(&wwandev->dev, NULL, is_wwan_child); if (!ret) { +#ifdef CONFIG_WWAN_DEBUGFS debugfs_remove_recursive(wwandev->debugfs_dir); +#endif device_unregister(&wwandev->dev); } else { put_device(&wwandev->dev); @@ -1140,7 +1147,9 @@ static int __init wwan_init(void) goto destroy; } +#ifdef CONFIG_WWAN_DEBUGFS wwan_debugfs_dir = debugfs_create_dir("wwan", NULL); +#endif return 0; |