On Thu Aug 14, 2025 at 3:07 PM CEST, Alexey Gladkov wrote:
> At this point, if a symbol is compiled as part of the kernel,
> information about which module the symbol belongs to is lost.
>
> To save this it is possible to add the module name to the alias name.
> It's not very pretty, but it's possible for now.
>
> Cc: Miguel Ojeda <oj...@kernel.org>
> Cc: Andreas Hindborg <a.hindb...@kernel.org>
> Cc: Danilo Krummrich <d...@kernel.org>
> Cc: Alex Gaynor <alex.gay...@gmail.com>
> Cc: rust-for-li...@vger.kernel.org
> Signed-off-by: Alexey Gladkov <leg...@kernel.org>
> ---
> include/linux/module.h | 14 +++++++++++++-
> rust/kernel/device_id.rs | 8 ++++----
> scripts/mod/file2alias.c | 18 ++++++++++++++----
> 3 files changed, 31 insertions(+), 9 deletions(-)
>
> diff --git a/include/linux/module.h b/include/linux/module.h
> index 3319a5269d28..e31ee29fac6b 100644
> --- a/include/linux/module.h
> +++ b/include/linux/module.h
> @@ -244,10 +244,22 @@ struct module_kobject
> *lookup_or_create_module_kobject(const char *name);
> /* What your module does. */
> #define MODULE_DESCRIPTION(_description) MODULE_INFO(description,
> _description)
>
> +/*
> + * Format: __mod_device_table__kmod_<modname>__<type>__<name>
> + * Parts of the string `__kmod_` and `__` are used as delimiters when parsing
> + * a symbol in file2alias.c
> + */
> +#define __mod_device_table(type, name) \
> + __PASTE(__mod_device_table__, \
> + __PASTE(__KBUILD_MODNAME, \
> + __PASTE(__, \
> + __PASTE(type, \
> + __PASTE(__, name)))))
> +
> #ifdef MODULE
> /* Creates an alias so file2alias.c can find device table. */
> #define MODULE_DEVICE_TABLE(type, name)
> \
> -static typeof(name) __mod_device_table__##type##__##name \
> +static typeof(name) __mod_device_table(type, name) \
> __attribute__ ((used, alias(__stringify(name))))
> #else /* !MODULE */
> #define MODULE_DEVICE_TABLE(type, name)
> diff --git a/rust/kernel/device_id.rs b/rust/kernel/device_id.rs
> index 70d57814ff79..62c42da12e9d 100644
> --- a/rust/kernel/device_id.rs
> +++ b/rust/kernel/device_id.rs
> @@ -195,10 +195,10 @@ macro_rules! module_device_table {
> ($table_type: literal, $module_table_name:ident, $table_name:ident) => {
> #[rustfmt::skip]
> #[export_name =
> - concat!("__mod_device_table__", $table_type,
> - "__", module_path!(),
> - "_", line!(),
> - "_", stringify!($table_name))
> + concat!("__mod_device_table__", line!(),
Why do we have line!() between "__mod_device_table__" and "__kmod_", while the
format is defined as "__mod_device_table__kmod_<modname>__<type>__<name>" above?
The previous logic was to create a unique name with
using "<module_path>_<line>_<table_name>" as "<name>". So, I think this should
actually be:
concat!("__mod_device_table__kmod_",
module_path!(),
"__", $table_type,
"__", stringify!($table_name),
"_", line!())
rather than the below.
> + "__kmod_", module_path!(),
> + "__", $table_type,
> + "__", stringify!($table_name))
> ]
> static $module_table_name: [::core::mem::MaybeUninit<u8>;
> $table_name.raw_ids().size()] =
> unsafe { ::core::mem::transmute_copy($table_name.raw_ids()) };
