kernel/linux.git/scripts/mod/modpost.c, branch v7.3-rc1

Merge tag 'objtool-core-2026-08-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2026-08-18T19:18:33+00:00

Pull objtool updates from Ingo Molnar: - Fix various klp-build bugs reported by Joe Lawrence (Josh Poimboeuf, Joe Lawrence) - Misc fixes and cleanups (Puranjay Mohan, Thomas Huth and Ingo Molnar) * tag 'objtool-core-2026-08-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: objtool/klp: Fix vmlinux klp relocations for EXPORT_SYMBOL_FOR_MODULES() objtool/klp: Fix .kcfi_traps special section extraction objtool/klp: Fix vmlinux .klp.symid link error for .exitcall.exit symbols objtool/klp: Fix line numbers in Module.symvers parse errors objtool/klp: Fix relocations for EXPORT_SYMBOL_FOR_MODULES() symbols objtool/klp: Allow new references to module exports objtool/klp: Don't match local symbols against exports objtool/klp: Fix cross-module klp relocation section naming objtool/klp: Explicitly disallow patching or referencing init code/data objtool/klp: Ignore replacement offset of empty x86 alternatives objtool/klp: Fix size of empty special section entries objtool/klp: Fix vmlinux .klp.symid link error for .no_trim_symbol symbols objtool/headers: Sync tools/include/linux/objtool_types.h with include/linux/objtool_types.h objtool: Replace __ASSEMBLY__ with __ASSEMBLER__ in header files objtool/klp: Fix symbol resolution for duplicate data symbols objtool/klp: Add .klp.symid for sympos disambiguation objtool/klp: Skip hidden directories when finding objects objtool/klp: Fix false module dependencies caused by dead relocs objtool/klp: Normalize Module.symvers paths to module names objtool/klp: Fix module name normalization for paths with dots

modpost: use mod_warn() and mod_error(), clean up logging

2026-08-15T19:01:51+00:00

Convert all module name logging to use the mod_warn() and mod_error() helpers, and pass the module to modpost_log() where used directly, to always have the module name prefixed in the log message, with .ko suffix for modules. Pass struct module *mod around in a few places instead of just mod->name. Further unify the logging while at it. Use single quotes instead of double quotes for symbols, sections, and namespaces. Explicitly state it's a "symbol" when referencing symbols. Signed-off-by: Jani Nikula Link: https://patch.msgid.link/17ed1bce5d54fb32533ba83bc83c429cb71adcb0.1786120005.git.jani.nikula@intel.com Reviewed-by: Nicolas Schier Reviewed-by: Nathan Chancellor Signed-off-by: Nicolas Schier

modpost: add module as parameter to modpost_log()

2026-08-14T19:34:40+00:00

modpost has a lot of error logging with module name, but the module name is logged in a plethora of ways. Add struct module * parameter to modpost_log(), and wrappers mod_warn() and mod_error(), to allow logging with a unified module name, if provided. If the module is provided, the messages will be of the format: (ERROR|WARNING): modpost: (modname.ko|vmlinux): message Actual conversion is done separately. Signed-off-by: Jani Nikula Link: https://patch.msgid.link/f27bd8810f0ef12fb86068f0190e4e0afa81e0fa.1786120005.git.jani.nikula@intel.com Reviewed-by: Nathan Chancellor Reviewed-by: Nicolas Schier Signed-off-by: Nicolas Schier

modpost: prevent leak when early return no suffix .o in read_symbols()

2026-08-05T12:51:58+00:00

The allocation for elf info symsearch and hdr from parse_elf() haven't been released when return because of modname didn't have suffix ".o". And it seems like the suffix ".o" check did not depends on parse_elf() to succeed first. So, move the suffix ".o" check before checking parse_elf() result to prevent resource leak when the modname didn't have suffix ".o" and return early. This is reported by Coverity Scan as "Resource leak". Fixes: 8c9ce89c5b63 ("modpost: simplify mod->name allocation") Signed-off-by: Robertus Diawan Chris Reviewed-by: Nathan Chancellor Link: https://patch.msgid.link/20260624044742.144852-1-robertusdchris@gmail.com Signed-off-by: Nicolas Schier

objtool/klp: Add .klp.symid for sympos disambiguation

2026-08-03T05:12:39+00:00

Livepatch identifies a duplicate-named symbol by its position (sympos) among same-named kallsyms entries, which for vmlinux are counted in ascending address order in the final linked kernel. That order can't be reliably derived from vmlinux.o: the final link reorders sub-sections (.text.unlikely*, .data..*, etc). Bridge the gap with a new .klp.symid section which can be used to correlate symbols between vmlinux.o and vmlinux so that klp-diff can reliably determine the sympos. The table can't survive --gc-sections: keeping it alive would keep every duplicate-named symbol's section alive, so the reference kernel would stop matching the one which ships. klp-build rejects CONFIG_LD_DEAD_CODE_DATA_ELIMINATION instead. Nothing is lost today: x86_64 is the only HAVE_KLP_BUILD arch and doesn't select HAVE_LD_DEAD_CODE_DATA_ELIMINATION, arm64 and s390 have never selected it either, and on powerpc, it's still EXPERIMENTAL and disabled by every distro kernel. This is the build-time half of reliable vmlinux sympos computation; "objtool klp diff" will consume the table in a subsequent commit. Signed-off-by: Josh Poimboeuf Signed-off-by: Ingo Molnar Cc: live-patching@vger.kernel.org Link: https://patch.msgid.link/64d50f077b569f47883c015cdb7079edb068efe8.1785727106.git.jpoimboe@kernel.org

modpost: Ignore Clang LTO suffixes in symbol matching

2026-06-18T18:35:22+00:00

When building the kernel with Clang ThinLTO enabled, the compiler can mangle static variable names by appending suffixes such as ".llvm." to prevent naming collisions across translation units. This name mangling breaks the section mismatch whitelisting in modpost. modpost relies on glob patterns (e.g., "*_ops" or "*_probe") to identify safe references between permanent data and initialization code. Because the LTO suffix modifies the end of the symbol name, legitimately whitelisted structures fail the match, resulting in false positive warnings. For example, a static pernet_operations struct triggers the following: WARNING: modpost: vmlinux: section mismatch in reference: \ ping_v4_net_ops.llvm.5641696707737373282 (section: .data) -> \ ping_v4_proc_init_net (section: .init.text) Fix this by ignoring "*_ops.llvm.*" in "from" symbol names (the same as "*_ops"). Reported-by: kernel test robot Closes: https://lore.kernel.org/oe-kbuild-all/202606111233.kM8oo8Df-lkp@intel.com/ Signed-off-by: Rong Xu Link: https://patch.msgid.link/20260617224623.1346309-1-xur@google.com Signed-off-by: Nathan Chancellor

modpost: Add __llvm_covfun and __llvm_covmap to section_white_list

2026-06-06T03:48:58+00:00

Modpost emits hundreds of warnings when using Clang to build for ARCH=um and CONFIG_GCOV=y. e.g.: vmlinux (__llvm_covfun): unexpected non-allocatable section. Did you forget to use "ax"/"aw" in a .S file? Note that for example contains section definitions for use in .S files. For example, when we use LLVM for a kunit user mode build with coverage: python3 tools/testing/kunit/kunit.py build --make_options LLVM=1 \ --kunitconfig=tools/testing/kunit/configs/default.config \ --kunitconfig=tools/testing/kunit/configs/coverage_uml.config The behaviour occurs when building the kernel for ARCH=um with code coverage enabled. The warnings come from modpost's check_sec_ref function, which ensures no sections reference others that will be discarded. covfun and covmap sections must reference __init and __exit sections to collect coverage data, triggering the modpost warning. To suppress these warnings, these section names have been added to modpost's whitelist. This is unlikely to suppress legitimate warnings as Clang will only insert these sections when building with coverage, and can be assumed to manage these references safely. Signed-off-by: James Lee Link: https://patch.msgid.link/20260604-dev-coverage-patch-v1-1-9f9368253cb4@codeconstruct.com.au Signed-off-by: Nathan Chancellor

kbuild: distributed build support for Clang ThinLTO

2026-05-29T20:44:29+00:00

Add distributed ThinLTO build support for the Linux kernel. This new mode offers several advantages: (1) Increased flexibility in handling user-specified build options. (2) Improved user-friendliness for developers. (3) Greater convenience for integrating with objtool and livepatch. Note that "distributed" in this context refers to a term that differentiates in-process ThinLTO builds by invoking backend compilation through the linker, not necessarily building in distributed environments. Distributed ThinLTO is enabled via the `CONFIG_LTO_CLANG_THIN_DIST` Kconfig option. For example: > make LLVM=1 defconfig > scripts/config -e LTO_CLANG_THIN_DIST > make LLVM=1 oldconfig > make LLVM=1 vmlinux -j <..> The build flow proceeds in four stages: 1. Perform FE compilation, mirroring the in-process ThinLTO mode. 2. Thin-link the generated IR files and object files. 3. Find all IR files and perform BE compilation, using the flags stored in the .*.o.cmd files. 4. Link the BE results to generate the final vmlinux.o. NOTE: This patch currently implements the build for the main kernel image (vmlinux) only. Kernel module support is planned for a subsequent patch. Tested on the following arch: x86, arm64, loongarch, and riscv. The earlier implementation details can be found here: https://discourse.llvm.org/t/rfc-distributed-thinlto-build-for-kernel/85934 Signed-off-by: Rong Xu Co-developed-by: Masahiro Yamada Signed-off-by: Masahiro Yamada Tested-by: Piotr Gorski Tested-by: Nathan Chancellor Link: https://patch.msgid.link/20260529185347.2418373-4-xur@google.com Signed-off-by: Nathan Chancellor

scripts: modpost: detect and report truncated buf_printf() output

2026-05-28T16:57:13+00:00

buf_printf() uses a fixed-size stack buffer. vsnprintf() returns the number of bytes that *would* have been written to that buffer, which can be larger than the size of said buffer if the formatted string is too long. The problem is that whenever this happens buf_printf() currently passes this length, unchecked, to buf_write(), which silently reads past the stack buffer and copies invalid data into the output buffer. Fix this by detecting vsnprintf() failures and truncations before appending to the output buffer, and report a fatal error instead of producing corrupt symbol names. Signed-off-by: Alexandre Courbot Link: https://patch.msgid.link/20260527-nova-exports-v2-1-06de4c556d55@nvidia.com Signed-off-by: Nathan Chancellor

Merge tag 'modules-7.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/modules/linux

2026-04-15T00:16:38+00:00

Pull module updates from Sami Tolvanen: "Kernel symbol flags: - Replace the separate *_gpl symbol sections (__ksymtab_gpl and __kcrctab_gpl) with a unified symbol table and a new __kflagstab section. This section stores symbol flags, such as the GPL-only flag, as an 8-bit bitset for each exported symbol. This is a cleanup that simplifies symbol lookup in the module loader by avoiding table fragmentation and will allow a cleaner way to add more flags later if needed. Module signature UAPI: - Move struct module_signature to the UAPI headers to allow reuse by tools outside the kernel proper, such as kmod and scripts/sign-file. This also renames a few constants for clarity and drops unused signature types as preparation for hash-based module integrity checking work that's in progress. Sysfs: - Add a /sys/module//import_ns sysfs attribute to show the symbol namespaces imported by loaded modules. This makes it easier to verify driver API access at runtime on systems that care about such things (e.g. Android). Cleanups and fixes: - Force sh_addr to 0 for all sections in module.lds. This prevents non-zero section addresses when linking modules with 'ld.bfd -r', which confused elfutils. - Fix a memory leak of charp module parameters on module unload when the kernel is configured with CONFIG_SYSFS=n. - Override the -EEXIST error code returned by module_init() to userspace. This prevents confusion with the errno reserved by the module loader to indicate that a module is already loaded. - Simplify the warning message and drop the stack dump on positive returns from module_init(). - Drop unnecessary extern keywords from function declarations and synchronize parse_args() arguments with their implementation" * tag 'modules-7.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/modules/linux: (23 commits) module: Simplify warning on positive returns from module_init() module: Override -EEXIST module return documentation: remove references to *_gpl sections module: remove *_gpl sections from vmlinux and modules module: deprecate usage of *_gpl sections in module loader module: use kflagstab instead of *_gpl sections module: populate kflagstab in modpost module: add kflagstab section to vmlinux and modules module: define ksym_flags enumeration to represent kernel symbol flags selftests/bpf: verify_pkcs7_sig: Use 'struct module_signature' from the UAPI headers sign-file: use 'struct module_signature' from the UAPI headers tools uapi headers: add linux/module_signature.h module: Move 'struct module_signature' to UAPI module: Give MODULE_SIG_STRING a more descriptive name module: Give 'enum pkey_id_type' a more specific name module: Drop unused signature types extract-cert: drop unused definition of PKEY_ID_PKCS7 docs: symbol-namespaces: mention sysfs attribute module: expose imported namespaces via sysfs module: Remove extern keyword from param prototypes ...