Unverified Commit c7d3dd91 authored by Nathan Chancellor's avatar Nathan Chancellor
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Merge patch series "Add generated modalias to modules.builtin.modinfo" 

Alexey Gladkov says:

The modules.builtin.modinfo file is used by userspace (kmod to be specific) to
get information about builtin modules. Among other information about the module,
information about module aliases is stored. This is very important to determine
that a particular modalias will be handled by a module that is inside the
kernel.

There are several mechanisms for creating modalias for modules:

The first is to explicitly specify the MODULE_ALIAS of the macro. In this case,
the aliases go into the '.modinfo' section of the module if it is compiled
separately or into vmlinux.o if it is builtin into the kernel.

The second is the use of MODULE_DEVICE_TABLE followed by the use of the
modpost utility. In this case, vmlinux.o no longer has this information and
does not get it into modules.builtin.modinfo.

For example:

$ modinfo pci:v00008086d0000A36Dsv00001043sd00008694bc0Csc03i30
modinfo: ERROR: Module pci:v00008086d0000A36Dsv00001043sd00008694bc0Csc03i30 not found.

$ modinfo xhci_pci
name:           xhci_pci
filename:       (builtin)
license:        GPL
file:           drivers/usb/host/xhci-pci
description:    xHCI PCI Host Controller Driver

The builtin module is missing alias "pci:v*d*sv*sd*bc0Csc03i30*" which will be
generated by modpost if the module is built separately.

To fix this it is necessary to add the generated by modpost modalias to
modules.builtin.modinfo. Fortunately modpost already generates .vmlinux.export.c
for exported symbols. It is possible to add `.modinfo` for builtin modules and
modify the build system so that `.modinfo` section is extracted from the
intermediate vmlinux after modpost is executed.

Link: https://patch.msgid.link/cover.1758182101.git.legion@kernel.org


Signed-off-by: default avatarNathan Chancellor <nathan@kernel.org>
parents 95ee3364 3328d39a

arch/s390/kernel/vmlinux.lds.S

+5 −5
Original line number Diff line number Diff line
@@ -209,6 +209,11 @@ SECTIONS 
	. = ALIGN(PAGE_SIZE);

	_end = . ;



	/* Debugging sections.	*/

	STABS_DEBUG

	DWARF_DEBUG

	ELF_DETAILS



	/*

	 * uncompressed image info used by the decompressor

	 * it should match struct vmlinux_info
@@ -239,11 +244,6 @@ SECTIONS 
#endif

	} :NONE



	/* Debugging sections.	*/

	STABS_DEBUG

	DWARF_DEBUG

	ELF_DETAILS



	/*

	 * Make sure that the .got.plt is either completely empty or it

	 * contains only the three reserved double words.

drivers/scsi/BusLogic.c

+1 −3
Original line number Diff line number Diff line
@@ -3715,7 +3715,6 @@ static void __exit blogic_exit(void) 


__setup("BusLogic=", blogic_setup);



#ifdef MODULE

/*static const struct pci_device_id blogic_pci_tbl[] = {

	{ PCI_VENDOR_ID_BUSLOGIC, PCI_DEVICE_ID_BUSLOGIC_MULTIMASTER,

	  PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0},
@@ -3725,13 +3724,12 @@ __setup("BusLogic=", blogic_setup); 
	  PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0},

	{ }

};*/

static const struct pci_device_id blogic_pci_tbl[] = {

static const struct pci_device_id blogic_pci_tbl[] __maybe_unused = {

	{PCI_DEVICE(PCI_VENDOR_ID_BUSLOGIC, PCI_DEVICE_ID_BUSLOGIC_MULTIMASTER)},

	{PCI_DEVICE(PCI_VENDOR_ID_BUSLOGIC, PCI_DEVICE_ID_BUSLOGIC_MULTIMASTER_NC)},

	{PCI_DEVICE(PCI_VENDOR_ID_BUSLOGIC, PCI_DEVICE_ID_BUSLOGIC_FLASHPOINT)},

	{0, },

};

#endif

MODULE_DEVICE_TABLE(pci, blogic_pci_tbl);



module_init(blogic_init);

include/asm-generic/vmlinux.lds.h

+1 −1
Original line number Diff line number Diff line
@@ -831,6 +831,7 @@ defined(CONFIG_AUTOFDO_CLANG) || defined(CONFIG_PROPELLER_CLANG) 


/* Required sections not related to debugging. */

#define ELF_DETAILS							\

		.modinfo : { *(.modinfo) }				\

		.comment 0 : { *(.comment) }				\

		.symtab 0 : { *(.symtab) }				\

		.strtab 0 : { *(.strtab) }				\
@@ -1044,7 +1045,6 @@ defined(CONFIG_AUTOFDO_CLANG) || defined(CONFIG_PROPELLER_CLANG) 
	*(.discard.*)							\

	*(.export_symbol)						\

	*(.no_trim_symbol)						\

	*(.modinfo)							\

	/* ld.bfd warns about .gnu.version* even when not emitted */	\

	*(.gnu.version*)						\

include/linux/module.h

+13 −5
Original line number Diff line number Diff line
@@ -244,14 +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)



#ifdef MODULE

/*

 * 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)))))



/* 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)

#endif



/* Version of form [<epoch>:]<version>[-<extra-version>].

 * Or for CVS/RCS ID version, everything but the number is stripped.

rust/kernel/device_id.rs

+4 −4
Original line number Diff line number Diff line
@@ -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!(),

                    "__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()) };