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authorLinus Torvalds <torvalds@linux-foundation.org>2022-05-26 12:09:50 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2022-05-26 12:09:50 -0700
commitdf202b452fe6c6d6f1351bad485e2367ef1e644e (patch)
tree40a0ff091ef8e4194e0c5102fd721583ed0bc49e /Documentation
parent16477cdfefdb494235a675cc80563d736991d833 (diff)
parent5ce2176b81f77366bd02c27509b83049f0020544 (diff)
downloadlinux-df202b452fe6c6d6f1351bad485e2367ef1e644e.tar.bz2
Merge tag 'kbuild-v5.19' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild
Pull Kbuild updates from Masahiro Yamada: - Add HOSTPKG_CONFIG env variable to allow users to override pkg-config - Support W=e as a shorthand for KCFLAGS=-Werror - Fix CONFIG_IKHEADERS build to support toybox cpio - Add scripts/dummy-tools/pahole to ease distro packagers' life - Suppress false-positive warnings from checksyscalls.sh for W=2 build - Factor out the common code of arch/*/boot/install.sh into scripts/install.sh - Support 'kernel-install' tool in scripts/prune-kernel - Refactor module-versioning to link the symbol versions at the final link of vmlinux and modules - Remove CONFIG_MODULE_REL_CRCS because module-versioning now works in an arch-agnostic way - Refactor modpost, Makefiles * tag 'kbuild-v5.19' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (56 commits) genksyms: adjust the output format to modpost kbuild: stop merging *.symversions kbuild: link symbol CRCs at final link, removing CONFIG_MODULE_REL_CRCS modpost: extract symbol versions from *.cmd files modpost: add sym_find_with_module() helper modpost: change the license of EXPORT_SYMBOL to bool type modpost: remove left-over cross_compile declaration kbuild: record symbol versions in *.cmd files kbuild: generate a list of objects in vmlinux modpost: move *.mod.c generation to write_mod_c_files() modpost: merge add_{intree_flag,retpoline,staging_flag} to add_header scripts/prune-kernel: Use kernel-install if available kbuild: factor out the common installation code into scripts/install.sh modpost: split new_symbol() to symbol allocation and hash table addition modpost: make sym_add_exported() always allocate a new symbol modpost: make multiple export error modpost: dump Module.symvers in the same order of modules.order modpost: traverse the namespace_list in order modpost: use doubly linked list for dump_lists modpost: traverse unresolved symbols in order ...
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/kbuild/kconfig-language.rst6
1 files changed, 6 insertions, 0 deletions
diff --git a/Documentation/kbuild/kconfig-language.rst b/Documentation/kbuild/kconfig-language.rst
index 93a5b6e1fabd..a7173843a294 100644
--- a/Documentation/kbuild/kconfig-language.rst
+++ b/Documentation/kbuild/kconfig-language.rst
@@ -693,6 +693,8 @@ in documenting basic Kconfig syntax a more precise definition of Kconfig
semantics is welcomed. One project deduced Kconfig semantics through
the use of the xconfig configurator [1]_. Work should be done to confirm if
the deduced semantics matches our intended Kconfig design goals.
+Another project formalized a denotational semantics of a core subset of
+the Kconfig language [10]_.
Having well defined semantics can be useful for tools for practical
evaluation of dependencies, for instance one such case was work to
@@ -700,6 +702,8 @@ express in boolean abstraction of the inferred semantics of Kconfig to
translate Kconfig logic into boolean formulas and run a SAT solver on this to
find dead code / features (always inactive), 114 dead features were found in
Linux using this methodology [1]_ (Section 8: Threats to validity).
+The kismet tool, based on the semantics in [10]_, finds abuses of reverse
+dependencies and has led to dozens of committed fixes to Linux Kconfig files [11]_.
Confirming this could prove useful as Kconfig stands as one of the leading
industrial variability modeling languages [1]_ [2]_. Its study would help
@@ -738,3 +742,5 @@ https://kernelnewbies.org/KernelProjects/kconfig-sat
.. [7] https://vamos.cs.fau.de
.. [8] https://undertaker.cs.fau.de
.. [9] https://www4.cs.fau.de/Publications/2011/tartler_11_eurosys.pdf
+.. [10] https://paulgazzillo.com/papers/esecfse21.pdf
+.. [11] https://github.com/paulgazz/kmax