[PATCH v13 3/5] modules: Allow extended modversions without basic MODVERSIONS
From: Matthew Maurer <hidden>
Date: 2025-01-03 17:37:10
Also in:
linux-doc, linux-kbuild, linux-modules, lkml, rust-for-linux
Subsystem:
kernel build + files below scripts/ (unless maintained elsewhere), module support, the rest · Maintainers:
Nathan Chancellor, Nicolas Schier, Luis Chamberlain, Petr Pavlu, Daniel Gomez, Sami Tolvanen, Linus Torvalds
If you know that your kernel modules will only ever be loaded by a newer kernel, you can disable BASIC_MODVERSIONS to save space. This also allows easy creation of test modules to see how tooling will respond to modules that only have the new format. Signed-off-by: Matthew Maurer <redacted> --- kernel/module/Kconfig | 15 +++++++++++++++ scripts/Makefile.modpost | 1 + scripts/mod/modpost.c | 9 +++++++-- 3 files changed, 23 insertions(+), 2 deletions(-)
diff --git a/kernel/module/Kconfig b/kernel/module/Kconfig
index 9568b629a03ce8289d3f3597eefc66fc96445720..4538f3af63e1ca531d0f74ef45a6f5268e505aec 100644
--- a/kernel/module/Kconfig
+++ b/kernel/module/Kconfig@@ -217,6 +217,21 @@ config EXTENDED_MODVERSIONS The most likely reason you would enable this is to enable Rust support. If unsure, say N. +config BASIC_MODVERSIONS + bool "Basic Module Versioning Support" + depends on MODVERSIONS + default y + help + This enables basic MODVERSIONS support, allowing older tools or + kernels to potentially load modules. + + Disabling this may cause older `modprobe` or `kmod` to be unable + to read MODVERSIONS information from built modules. With this + disabled, older kernels may treat this module as unversioned. + + This is enabled by default when MODVERSIONS are enabled. + If unsure, say Y. + config MODULE_SRCVERSION_ALL bool "Source checksum for all modules" help
diff --git a/scripts/Makefile.modpost b/scripts/Makefile.modpost
index 40426fc6350985780c0092beb49c6cc29b9eff62..d7d45067d08b94a82451d66a64eae29b6826e139 100644
--- a/scripts/Makefile.modpost
+++ b/scripts/Makefile.modpost@@ -43,6 +43,7 @@ MODPOST = $(objtree)/scripts/mod/modpost modpost-args = \ $(if $(CONFIG_MODULES),-M) \ $(if $(CONFIG_MODVERSIONS),-m) \ + $(if $(CONFIG_BASIC_MODVERSIONS),-b) \ $(if $(CONFIG_EXTENDED_MODVERSIONS),-x) \ $(if $(CONFIG_MODULE_SRCVERSION_ALL),-a) \ $(if $(CONFIG_SECTION_MISMATCH_WARN_ONLY),,-E) \
diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
index 6324b30f6b97ac24dc517b9229f227c6c369f7d5..3784f1e08104dc2ca1da10d45ed92bb8adf4826a 100644
--- a/scripts/mod/modpost.c
+++ b/scripts/mod/modpost.c@@ -33,6 +33,8 @@ static bool module_enabled; static bool modversions; /* Is CONFIG_MODULE_SRCVERSION_ALL set? */ static bool all_versions; +/* Is CONFIG_BASIC_MODVERSIONS set? */ +static bool basic_modversions; /* Is CONFIG_EXTENDED_MODVERSIONS set? */ static bool extended_modversions; /* If we are modposting external module set to 1 */
@@ -1856,7 +1858,7 @@ static void add_versions(struct buffer *b, struct module *mod) { struct symbol *s; - if (!modversions) + if (!basic_modversions) return; buf_printf(b, "\n");
@@ -2176,7 +2178,7 @@ int main(int argc, char **argv) LIST_HEAD(dump_lists); struct dump_list *dl, *dl2; - while ((opt = getopt(argc, argv, "ei:MmnT:to:au:WwENd:x")) != -1) { + while ((opt = getopt(argc, argv, "ei:MmnT:to:au:WwENd:xb")) != -1) { switch (opt) { case 'e': external_module = true;
@@ -2225,6 +2227,9 @@ int main(int argc, char **argv) case 'd': missing_namespace_deps = optarg; break; + case 'b': + basic_modversions = true; + break; case 'x': extended_modversions = true; break;
--
2.47.1.613.gc27f4b7a9f-goog