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author | Linus Torvalds <torvalds@linux-foundation.org> | 2019-09-22 10:34:46 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2019-09-22 10:34:46 -0700 |
commit | e0703556644a531e50b5dc61b9f6ea83af5f6604 (patch) | |
tree | a0aa73809630d716f25b124cd2aa99a1f4743a55 /init/Kconfig | |
parent | 8808cf8cbc4da1ceef9307fba7e499563908c211 (diff) | |
parent | 2e6fcfeb9df6048a63fe0d5f7dfa39274bacbb71 (diff) | |
download | linux-e0703556644a531e50b5dc61b9f6ea83af5f6604.tar.gz linux-e0703556644a531e50b5dc61b9f6ea83af5f6604.tar.bz2 linux-e0703556644a531e50b5dc61b9f6ea83af5f6604.zip |
Merge tag 'modules-for-v5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux
Pull modules updates from Jessica Yu:
"The main bulk of this pull request introduces a new exported symbol
namespaces feature. The number of exported symbols is increasingly
growing with each release (we're at about 31k exports as of 5.3-rc7)
and we currently have no way of visualizing how these symbols are
"clustered" or making sense of this huge export surface.
Namespacing exported symbols allows kernel developers to more
explicitly partition and categorize exported symbols, as well as more
easily limiting the availability of namespaced symbols to other parts
of the kernel. For starters, we have introduced the USB_STORAGE
namespace to demonstrate the API's usage. I have briefly summarized
the feature and its main motivations in the tag below.
Summary:
- Introduce exported symbol namespaces.
This new feature allows subsystem maintainers to partition and
categorize their exported symbols into explicit namespaces. Module
authors are now required to import the namespaces they need.
Some of the main motivations of this feature include: allowing
kernel developers to better manage the export surface, allow
subsystem maintainers to explicitly state that usage of some
exported symbols should only be limited to certain users (think:
inter-module or inter-driver symbols, debugging symbols, etc), as
well as more easily limiting the availability of namespaced symbols
to other parts of the kernel.
With the module import requirement, it is also easier to spot the
misuse of exported symbols during patch review.
Two new macros are introduced: EXPORT_SYMBOL_NS() and
EXPORT_SYMBOL_NS_GPL(). The API is thoroughly documented in
Documentation/kbuild/namespaces.rst.
- Some small code and kbuild cleanups here and there"
* tag 'modules-for-v5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux:
module: Remove leftover '#undef' from export header
module: remove unneeded casts in cmp_name()
module: move CONFIG_UNUSED_SYMBOLS to the sub-menu of MODULES
module: remove redundant 'depends on MODULES'
module: Fix link failure due to invalid relocation on namespace offset
usb-storage: export symbols in USB_STORAGE namespace
usb-storage: remove single-use define for debugging
docs: Add documentation for Symbol Namespaces
scripts: Coccinelle script for namespace dependencies.
modpost: add support for generating namespace dependencies
export: allow definition default namespaces in Makefiles or sources
module: add config option MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS
modpost: add support for symbol namespaces
module: add support for symbol namespaces.
export: explicitly align struct kernel_symbol
module: support reading multiple values per modinfo tag
Diffstat (limited to 'init/Kconfig')
-rw-r--r-- | init/Kconfig | 33 |
1 files changed, 30 insertions, 3 deletions
diff --git a/init/Kconfig b/init/Kconfig index 058ba4e74250..57123594a7ca 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -2047,7 +2047,6 @@ config MODULE_SRCVERSION_ALL config MODULE_SIG bool "Module signature verification" - depends on MODULES select SYSTEM_DATA_VERIFICATION help Check modules for valid signatures upon load: the signature @@ -2124,7 +2123,6 @@ config MODULE_SIG_HASH config MODULE_COMPRESS bool "Compress modules on installation" - depends on MODULES help Compresses kernel modules when 'make modules_install' is run; gzip or @@ -2160,9 +2158,38 @@ config MODULE_COMPRESS_XZ endchoice +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 UNUSED_SYMBOLS + bool "Enable unused/obsolete exported symbols" + default y if X86 + help + Unused but exported symbols make the kernel needlessly bigger. For + that reason most of these unused exports will soon be removed. This + option is provided temporarily to provide a transition period in case + some external kernel module needs one of these symbols anyway. If you + encounter such a case in your module, consider if you are actually + using the right API. (rationale: since nobody in the kernel is using + this in a module, there is a pretty good chance it's actually the + wrong interface to use). If you really need the symbol, please send a + mail to the linux kernel mailing list mentioning the symbol and why + you really need it, and what the merge plan to the mainline kernel for + your module is. + config TRIM_UNUSED_KSYMS bool "Trim unused exported kernel symbols" - depends on MODULES && !UNUSED_SYMBOLS + depends on !UNUSED_SYMBOLS help The kernel and some modules make many symbols available for other modules to use via EXPORT_SYMBOL() and variants. Depending |