[PATCH] modules: move module symbols from init/Kconfig

Luis Chamberlain
2022-07-11T16:20:58Z

This moves all the module symbols from init/Kconfig to its
own dedicated file now that we have all of the module code in
its own directory.

This does not introduce any functional changes.

Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
---
init/Kconfig | 298 +-----------------------------------------
kernel/module/Kconfig | 296 +++++++++++++++++++++++++++++++++++++++++
2 files changed, 297 insertions(+), 297 deletions(-)
create mode 100644 kernel/module/Kconfig

diff --git a/init/Kconfig b/init/Kconfig
index c7900e8975f1..afb45347b775 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -1918,303 +1918,6 @@ config BASE_SMALL
default 0 if BASE_FULL
default 1 if !BASE_FULL

-config MODULE_SIG_FORMAT
- def_bool n
- select SYSTEM_DATA_VERIFICATION
-
-menuconfig MODULES
- bool "Enable loadable module support"
- modules
- help
- Kernel modules are small pieces of compiled code which can
- be inserted in the running kernel, rather than being
- permanently built into the kernel. You use the "modprobe"
- tool to add (and sometimes remove) them. If you say Y here,
- many parts of the kernel can be built as modules (by
- answering M instead of Y where indicated): this is most
- useful for infrequently used options which are not required
- for booting. For more information, see the man pages for
- modprobe, lsmod, modinfo, insmod and rmmod.
-
- If you say Y here, you will need to run "make
- modules_install" to put the modules under /lib/modules/
- where modprobe can find them (you may need to be root to do
- this).
-
- If unsure, say Y.
-
-if MODULES
-
-config MODULE_FORCE_LOAD
- bool "Forced module loading"
- default n
- help
- Allow loading of modules without version information (ie. modprobe
- --force). Forced module loading sets the 'F' (forced) taint flag and
- is usually a really bad idea.
-
-config MODULE_UNLOAD
- bool "Module unloading"
- help
- Without this option you will not be able to unload any
- modules (note that some modules may not be unloadable
- anyway), which makes your kernel smaller, faster
- and simpler. If unsure, say Y.
-
-config MODULE_FORCE_UNLOAD
- bool "Forced module unloading"
- depends on MODULE_UNLOAD
- help
- This option allows you to force a module to unload, even if the
- kernel believes it is unsafe: the kernel will remove the module
- without waiting for anyone to stop using it (using the -f option to
- rmmod). This is mainly for kernel developers and desperate users.
- If unsure, say N.
-
-config MODULE_UNLOAD_TAINT_TRACKING
- bool "Tainted module unload tracking"
- depends on MODULE_UNLOAD
- default n
- help
- This option allows you to maintain a record of each unloaded
- module that tainted the kernel. In addition to displaying a
- list of linked (or loaded) modules e.g. on detection of a bad
- page (see bad_page()), the aforementioned details are also
- shown. If unsure, say N.
-
-config MODVERSIONS
- bool "Module versioning support"
- help
- Usually, you have to use modules compiled with your kernel.
- Saying Y here makes it sometimes possible to use modules
- compiled for different kernels, by adding enough information
- to the modules to (hopefully) spot any changes which would
- make them incompatible with the kernel you are running. If
- unsure, say N.
-
-config ASM_MODVERSIONS
- bool
- default HAVE_ASM_MODVERSIONS && MODVERSIONS
- help
- This enables module versioning for exported symbols also from
- assembly. This can be enabled only when the target architecture
- supports it.
-
-config MODULE_SRCVERSION_ALL
- bool "Source checksum for all modules"
- help
- Modules which contain a MODULE_VERSION get an extra "srcversion"
- field inserted into their modinfo section, which contains a
- sum of the source files which made it. This helps maintainers
- see exactly which source was used to build a module (since
- others sometimes change the module source without updating
- the version). With this option, such a "srcversion" field
- will be created for all modules. If unsure, say N.
-
-config MODULE_SIG
- bool "Module signature verification"
- select MODULE_SIG_FORMAT
- help
- Check modules for valid signatures upon load: the signature
- is simply appended to the module. For more information see
- <file:Documentation/admin-guide/module-signing.rst>.
-
- Note that this option adds the OpenSSL development packages as a
- kernel build dependency so that the signing tool can use its crypto
- library.
-
- You should enable this option if you wish to use either
- CONFIG_SECURITY_LOCKDOWN_LSM or lockdown functionality imposed via
- another LSM - otherwise unsigned modules will be loadable regardless
- of the lockdown policy.
-
- !!!WARNING!!! If you enable this option, you MUST make sure that the
- module DOES NOT get stripped after being signed. This includes the
- debuginfo strip done by some packagers (such as rpmbuild) and
- inclusion into an initramfs that wants the module size reduced.
-
-config MODULE_SIG_FORCE
- bool "Require modules to be validly signed"
- depends on MODULE_SIG
- help
- Reject unsigned modules or signed modules for which we don't have a
- key. Without this, such modules will simply taint the kernel.
-
-config MODULE_SIG_ALL
- bool "Automatically sign all modules"
- default y
- depends on MODULE_SIG || IMA_APPRAISE_MODSIG
- help
- Sign all modules during make modules_install. Without this option,
- modules must be signed manually, using the scripts/sign-file tool.
-
-comment "Do not forget to sign required modules with scripts/sign-file"
- depends on MODULE_SIG_FORCE && !MODULE_SIG_ALL
-
-choice
- prompt "Which hash algorithm should modules be signed with?"
- depends on MODULE_SIG || IMA_APPRAISE_MODSIG
- help
- This determines which sort of hashing algorithm will be used during
- signature generation. This algorithm _must_ be built into the kernel
- directly so that signature verification can take place. It is not
- possible to load a signed module containing the algorithm to check
- the signature on that module.
-
-config MODULE_SIG_SHA1
- bool "Sign modules with SHA-1"
- select CRYPTO_SHA1
-
-config MODULE_SIG_SHA224
- bool "Sign modules with SHA-224"
- select CRYPTO_SHA256
-
-config MODULE_SIG_SHA256
- bool "Sign modules with SHA-256"
- select CRYPTO_SHA256
-
-config MODULE_SIG_SHA384
- bool "Sign modules with SHA-384"
- select CRYPTO_SHA512
-
-config MODULE_SIG_SHA512
- bool "Sign modules with SHA-512"
- select CRYPTO_SHA512
-
-endchoice
-
-config MODULE_SIG_HASH
- string
- depends on MODULE_SIG || IMA_APPRAISE_MODSIG
- default "sha1" if MODULE_SIG_SHA1
- default "sha224" if MODULE_SIG_SHA224
- default "sha256" if MODULE_SIG_SHA256
- default "sha384" if MODULE_SIG_SHA384
- default "sha512" if MODULE_SIG_SHA512
-
-choice
- prompt "Module compression mode"
- help
- This option allows you to choose the algorithm which will be used to
- compress modules when 'make modules_install' is run. (or, you can
- choose to not compress modules at all.)
-
- External modules will also be compressed in the same way during the
- installation.
-
- For modules inside an initrd or initramfs, it's more efficient to
- compress the whole initrd or initramfs instead.
-
- This is fully compatible with signed modules.
-
- Please note that the tool used to load modules needs to support the
- corresponding algorithm. module-init-tools MAY support gzip, and kmod
- MAY support gzip, xz and zstd.
-
- Your build system needs to provide the appropriate compression tool
- to compress the modules.
-
- If in doubt, select 'None'.
-
-config MODULE_COMPRESS_NONE
- bool "None"
- help
- Do not compress modules. The installed modules are suffixed
- with .ko.
-
-config MODULE_COMPRESS_GZIP
- bool "GZIP"
- help
- Compress modules with GZIP. The installed modules are suffixed
- with .ko.gz.
-
-config MODULE_COMPRESS_XZ
- bool "XZ"
- help
- Compress modules with XZ. The installed modules are suffixed
- with .ko.xz.
-
-config MODULE_COMPRESS_ZSTD
- bool "ZSTD"
- help
- Compress modules with ZSTD. The installed modules are suffixed
- with .ko.zst.
-
-endchoice
-
-config MODULE_DECOMPRESS
- bool "Support in-kernel module decompression"
- depends on MODULE_COMPRESS_GZIP || MODULE_COMPRESS_XZ
- select ZLIB_INFLATE if MODULE_COMPRESS_GZIP
- select XZ_DEC if MODULE_COMPRESS_XZ
- help
-
- Support for decompressing kernel modules by the kernel itself
- instead of relying on userspace to perform this task. Useful when
- load pinning security policy is enabled.
-
- If unsure, say N.
-
-config MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS
- bool "Allow loading of modules with missing namespace imports"
- help
- Symbols exported with EXPORT_SYMBOL_NS*() are considered exported in
- a namespace. A module that makes use of a symbol exported with such a
- namespace is required to import the namespace via MODULE_IMPORT_NS().
- There is no technical reason to enforce correct namespace imports,
- but it creates consistency between symbols defining namespaces and
- users importing namespaces they make use of. This option relaxes this
- requirement and lifts the enforcement when loading a module.
-
- If unsure, say N.
-
-config MODPROBE_PATH
- string "Path to modprobe binary"
- default "/sbin/modprobe"
- help
- When kernel code requests a module, it does so by calling
- the "modprobe" userspace utility. This option allows you to
- set the path where that binary is found. This can be changed
- at runtime via the sysctl file
- /proc/sys/kernel/modprobe. Setting this to the empty string
- removes the kernel's ability to request modules (but
- userspace can still load modules explicitly).
-
-config TRIM_UNUSED_KSYMS
- bool "Trim unused exported kernel symbols" if EXPERT
- depends on !COMPILE_TEST
- help
- The kernel and some modules make many symbols available for
- other modules to use via EXPORT_SYMBOL() and variants. Depending
- on the set of modules being selected in your kernel configuration,
- many of those exported symbols might never be used.
-
- This option allows for unused exported symbols to be dropped from
- the build. In turn, this provides the compiler more opportunities
- (especially when using LTO) for optimizing the code and reducing
- binary size. This might have some security advantages as well.
-
- If unsure, or if you need to build out-of-tree modules, say N.
-
-config UNUSED_KSYMS_WHITELIST
- string "Whitelist of symbols to keep in ksymtab"
- depends on TRIM_UNUSED_KSYMS
- help
- By default, all unused exported symbols will be un-exported from the
- build when TRIM_UNUSED_KSYMS is selected.
-
- UNUSED_KSYMS_WHITELIST allows to whitelist symbols that must be kept
- exported at all times, even in absence of in-tree users. The value to
- set here is the path to a text file containing the list of symbols,
- one per line. The path can be absolute, or relative to the kernel
- source tree.
-
-endif # MODULES
-
-config MODULES_TREE_LOOKUP
- def_bool y
- depends on PERF_EVENTS || TRACING || CFI_CLANG
-
config INIT_ALL_POSSIBLE
bool
help
@@ -2224,6 +1927,7 @@ config INIT_ALL_POSSIBLE
it was better to provide this option than to break all the archs
and have several arch maintainers pursuing me down dark alleys.

+source "kernel/module/Kconfig"
source "block/Kconfig"

config PREEMPT_NOTIFIERS
diff --git a/kernel/module/Kconfig b/kernel/module/Kconfig
new file mode 100644
index 000000000000..5aff8a40c58e
--- /dev/null
+++ b/kernel/module/Kconfig
@@ -0,0 +1,296 @@
+config MODULE_SIG_FORMAT
+ def_bool n
+ select SYSTEM_DATA_VERIFICATION
+
+menuconfig MODULES
+ bool "Enable loadable module support"
+ modules
+ help
+ Kernel modules are small pieces of compiled code which can
+ be inserted in the running kernel, rather than being
+ permanently built into the kernel. You use the "modprobe"
+ tool to add (and sometimes remove) them. If you say Y here,
+ many parts of the kernel can be built as modules (by
+ answering M instead of Y where indicated): this is most
+ useful for infrequently used options which are not required
+ for booting. For more information, see the man pages for
+ modprobe, lsmod, modinfo, insmod and rmmod.
+
+ If you say Y here, you will need to run "make
+ modules_install" to put the modules under /lib/modules/
+ where modprobe can find them (you may need to be root to do
+ this).
+
+ If unsure, say Y.
+
+if MODULES
+
+config MODULE_FORCE_LOAD
+ bool "Forced module loading"
+ default n
+ help
+ Allow loading of modules without version information (ie. modprobe
+ --force). Forced module loading sets the 'F' (forced) taint flag and
+ is usually a really bad idea.
+
+config MODULE_UNLOAD
+ bool "Module unloading"
+ help
+ Without this option you will not be able to unload any
+ modules (note that some modules may not be unloadable
+ anyway), which makes your kernel smaller, faster
+ and simpler. If unsure, say Y.
+
+config MODULE_FORCE_UNLOAD
+ bool "Forced module unloading"
+ depends on MODULE_UNLOAD
+ help
+ This option allows you to force a module to unload, even if the
+ kernel believes it is unsafe: the kernel will remove the module
+ without waiting for anyone to stop using it (using the -f option to
+ rmmod). This is mainly for kernel developers and desperate users.
+ If unsure, say N.
+
+config MODULE_UNLOAD_TAINT_TRACKING
+ bool "Tainted module unload tracking"
+ depends on MODULE_UNLOAD
+ default n
+ help
+ This option allows you to maintain a record of each unloaded
+ module that tainted the kernel. In addition to displaying a
+ list of linked (or loaded) modules e.g. on detection of a bad
+ page (see bad_page()), the aforementioned details are also
+ shown. If unsure, say N.
+
+config MODVERSIONS
+ bool "Module versioning support"
+ help
+ Usually, you have to use modules compiled with your kernel.
+ Saying Y here makes it sometimes possible to use modules
+ compiled for different kernels, by adding enough information
+ to the modules to (hopefully) spot any changes which would
+ make them incompatible with the kernel you are running. If
+ unsure, say N.
+
+config ASM_MODVERSIONS
+ bool
+ default HAVE_ASM_MODVERSIONS && MODVERSIONS
+ help
+ This enables module versioning for exported symbols also from
+ assembly. This can be enabled only when the target architecture
+ supports it.
+
+config MODULE_SRCVERSION_ALL
+ bool "Source checksum for all modules"
+ help
+ Modules which contain a MODULE_VERSION get an extra "srcversion"
+ field inserted into their modinfo section, which contains a
+ sum of the source files which made it. This helps maintainers
+ see exactly which source was used to build a module (since
+ others sometimes change the module source without updating
+ the version). With this option, such a "srcversion" field
+ will be created for all modules. If unsure, say N.
+
+config MODULE_SIG
+ bool "Module signature verification"
+ select MODULE_SIG_FORMAT
+ help
+ Check modules for valid signatures upon load: the signature
+ is simply appended to the module. For more information see
+ <file:Documentation/admin-guide/module-signing.rst>.
+
+ Note that this option adds the OpenSSL development packages as a
+ kernel build dependency so that the signing tool can use its crypto
+ library.
+
+ You should enable this option if you wish to use either
+ CONFIG_SECURITY_LOCKDOWN_LSM or lockdown functionality imposed via
+ another LSM - otherwise unsigned modules will be loadable regardless
+ of the lockdown policy.
+
+ !!!WARNING!!! If you enable this option, you MUST make sure that the
+ module DOES NOT get stripped after being signed. This includes the
+ debuginfo strip done by some packagers (such as rpmbuild) and
+ inclusion into an initramfs that wants the module size reduced.
+
+config MODULE_SIG_FORCE
+ bool "Require modules to be validly signed"
+ depends on MODULE_SIG
+ help
+ Reject unsigned modules or signed modules for which we don't have a
+ key. Without this, such modules will simply taint the kernel.
+
+config MODULE_SIG_ALL
+ bool "Automatically sign all modules"
+ default y
+ depends on MODULE_SIG || IMA_APPRAISE_MODSIG
+ help
+ Sign all modules during make modules_install. Without this option,
+ modules must be signed manually, using the scripts/sign-file tool.
+
+comment "Do not forget to sign required modules with scripts/sign-file"
+ depends on MODULE_SIG_FORCE && !MODULE_SIG_ALL
+
+choice
+ prompt "Which hash algorithm should modules be signed with?"
+ depends on MODULE_SIG || IMA_APPRAISE_MODSIG
+ help
+ This determines which sort of hashing algorithm will be used during
+ signature generation. This algorithm _must_ be built into the kernel
+ directly so that signature verification can take place. It is not
+ possible to load a signed module containing the algorithm to check
+ the signature on that module.
+
+config MODULE_SIG_SHA1
+ bool "Sign modules with SHA-1"
+ select CRYPTO_SHA1
+
+config MODULE_SIG_SHA224
+ bool "Sign modules with SHA-224"
+ select CRYPTO_SHA256
+
+config MODULE_SIG_SHA256
+ bool "Sign modules with SHA-256"
+ select CRYPTO_SHA256
+
+config MODULE_SIG_SHA384
+ bool "Sign modules with SHA-384"
+ select CRYPTO_SHA512
+
+config MODULE_SIG_SHA512
+ bool "Sign modules with SHA-512"
+ select CRYPTO_SHA512
+
+endchoice
+
+config MODULE_SIG_HASH
+ string
+ depends on MODULE_SIG || IMA_APPRAISE_MODSIG
+ default "sha1" if MODULE_SIG_SHA1
+ default "sha224" if MODULE_SIG_SHA224
+ default "sha256" if MODULE_SIG_SHA256
+ default "sha384" if MODULE_SIG_SHA384
+ default "sha512" if MODULE_SIG_SHA512
+
+choice
+ prompt "Module compression mode"
+ help
+ This option allows you to choose the algorithm which will be used to
+ compress modules when 'make modules_install' is run. (or, you can
+ choose to not compress modules at all.)
+
+ External modules will also be compressed in the same way during the
+ installation.
+
+ For modules inside an initrd or initramfs, it's more efficient to
+ compress the whole initrd or initramfs instead.
+
+ This is fully compatible with signed modules.
+
+ Please note that the tool used to load modules needs to support the
+ corresponding algorithm. module-init-tools MAY support gzip, and kmod
+ MAY support gzip, xz and zstd.
+
+ Your build system needs to provide the appropriate compression tool
+ to compress the modules.
+
+ If in doubt, select 'None'.
+
+config MODULE_COMPRESS_NONE
+ bool "None"
+ help
+ Do not compress modules. The installed modules are suffixed
+ with .ko.
+
+config MODULE_COMPRESS_GZIP
+ bool "GZIP"
+ help
+ Compress modules with GZIP. The installed modules are suffixed
+ with .ko.gz.
+
+config MODULE_COMPRESS_XZ
+ bool "XZ"
+ help
+ Compress modules with XZ. The installed modules are suffixed
+ with .ko.xz.
+
+config MODULE_COMPRESS_ZSTD
+ bool "ZSTD"
+ help
+ Compress modules with ZSTD. The installed modules are suffixed
+ with .ko.zst.
+
+endchoice
+
+config MODULE_DECOMPRESS
+ bool "Support in-kernel module decompression"
+ depends on MODULE_COMPRESS_GZIP || MODULE_COMPRESS_XZ
+ select ZLIB_INFLATE if MODULE_COMPRESS_GZIP
+ select XZ_DEC if MODULE_COMPRESS_XZ
+ help
+
+ Support for decompressing kernel modules by the kernel itself
+ instead of relying on userspace to perform this task. Useful when
+ load pinning security policy is enabled.
+
+ If unsure, say N.
+
+config MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS
+ bool "Allow loading of modules with missing namespace imports"
+ help
+ Symbols exported with EXPORT_SYMBOL_NS*() are considered exported in
+ a namespace. A module that makes use of a symbol exported with such a
+ namespace is required to import the namespace via MODULE_IMPORT_NS().
+ There is no technical reason to enforce correct namespace imports,
+ but it creates consistency between symbols defining namespaces and
+ users importing namespaces they make use of. This option relaxes this
+ requirement and lifts the enforcement when loading a module.
+
+ If unsure, say N.
+
+config MODPROBE_PATH
+ string "Path to modprobe binary"
+ default "/sbin/modprobe"
+ help
+ When kernel code requests a module, it does so by calling
+ the "modprobe" userspace utility. This option allows you to
+ set the path where that binary is found. This can be changed
+ at runtime via the sysctl file
+ /proc/sys/kernel/modprobe. Setting this to the empty string
+ removes the kernel's ability to request modules (but
+ userspace can still load modules explicitly).
+
+config TRIM_UNUSED_KSYMS
+ bool "Trim unused exported kernel symbols" if EXPERT
+ depends on !COMPILE_TEST
+ help
+ The kernel and some modules make many symbols available for
+ other modules to use via EXPORT_SYMBOL() and variants. Depending
+ on the set of modules being selected in your kernel configuration,
+ many of those exported symbols might never be used.
+
+ This option allows for unused exported symbols to be dropped from
+ the build. In turn, this provides the compiler more opportunities
+ (especially when using LTO) for optimizing the code and reducing
+ binary size. This might have some security advantages as well.
+
+ If unsure, or if you need to build out-of-tree modules, say N.
+
+config UNUSED_KSYMS_WHITELIST
+ string "Whitelist of symbols to keep in ksymtab"
+ depends on TRIM_UNUSED_KSYMS
+ help
+ By default, all unused exported symbols will be un-exported from the
+ build when TRIM_UNUSED_KSYMS is selected.
+
+ UNUSED_KSYMS_WHITELIST allows to whitelist symbols that must be kept
+ exported at all times, even in absence of in-tree users. The value to
+ set here is the path to a text file containing the list of symbols,
+ one per line. The path can be absolute, or relative to the kernel
+ source tree.
+
+endif # MODULES
+
+config MODULES_TREE_LOOKUP
+ def_bool y
+ depends on PERF_EVENTS || TRACING || CFI_CLANG
--
2.35.1