On Mon, Jul 06, 2026 at 01:03:37AM -0400, Aaron Tomlin wrote: > Currently, the "module_blacklist=" command-line parameter only applies to > loadable modules. If a module is built-in, the parameter is silently > ignored. This patch extends the blacklisting functionality to built-in > modules by intercepting their initialization routines during early boot. > > To achieve this, we introduce a new ".initcall.modnames" memory section. > For each built-in module, we use a standard C structure (i.e., struct > initcall_modname) to map its initcall function pointer to its associated > KBUILD_MODNAME string. > > During boot, do_one_initcall() cross-references the initcall function > pointer against this table. If a match is found and the module is > present in the blacklist, the initcall is skipped.
Hi Arnd, Luis, Petr, Daniel, Sami, Please ignore. I will send a v4. Sashiko [1] correctly reported further issues (e.g., CONFIG_MODULES=n) which have been addressed as follows: - Decoupled the module_blacklist parameter parsing and the module_is_blacklisted() function from CONFIG_MODULES, moving the logic to init/main.c. This ensures the blacklist works for built-in modules even on monolithic kernels built without loadable module support (CONFIG_MODULES=n) - Removed the conditional stub implementation of module_is_blacklisted() in module.h and replaced it with a single, unconditional declaration outside of the #ifdef CONFIG_MODULES block. This prevents compiler warnings about missing prototypes and ensures visibility under a monolithic configuration - Replaced the initmem_freed state variable and its synchronisation logic in kernel_init() with race-free spatial boundary checks using is_kernel_text() and is_kernel_inittext() in initcall_get_modname() . - Aligned the .initcall_modnames table with relocations by assigning .initcall_fn using the __initcall_stub() helper in ___define_initcall(). This ensures the lookup matches the actual stub pointer passed to do_one_initcall() when CONFIG_HAVE_ARCH_PREL32_RELOCATIONS is enabled - Updated initcall_get_modname() in main.c to resolve the function pointer fn using dereference_function_descriptor(fn) prior to checking the .text and .init.text boundaries [1]: https://sashiko.dev/#/patchset/20260706050337.7613-1-atomlin%40atomlin.com -- Aaron Tomlin
