This patch series is intended for use alongside the Implement MODVERSIONS for RUST [1] series as a replacement for the symbol name hashing approach used there to enable RUST and MODVERSIONS at the same time. Elsewhere, we've seen a desire for long symbol name support for LTO symbol names [2], and the previous series came up [3] as a possible solution rather than hashing, which some have objected [4] to. This series adds a MODVERSIONS format which uses a section per column. This avoids userspace tools breaking if we need to make a similar change to the format in the future - we would do so by adding a new section, rather than editing the struct definition. In the new format, the name section is formatted as a concatenated sequence of NUL-terminated strings, which allows for arbitrary length names. Currently, this series emits both the extended format and the current format on all modules, and prefers the extended format when checking if present. I'm open to various other policies via Kconfig knobs, but this seemed like a good initial default. The refactor to MODVERSIONS is prefixed to this series as result of an explicit request [5] by Luis in response to the original patchset. If you are testing this patch alongside RUST by manually removing the !MODVERSIONS restriction (this series doesn't remove it, because the CRCs don't mean what we'd want them to yet, we need the DWARF patch for that) and have kernel hardening enabled, you may need the CPU Mitigations [6] series. Without it, the foo.mod.o file produced by the C compiler will reference __x86_return_thunk, but foo.o will not. This means that the version table will not contain a version for __x86_return_thunk, but foo.ko will reference it, which will result in a version check failure. [1] https://lore.kernel.org/all/20240617175818.58219-17-samitolvanen@xxxxxxxxxx/ [2] https://lore.kernel.org/lkml/20240605032120.3179157-1-song@xxxxxxxxxx/ [3] https://lore.kernel.org/lkml/ZoxbEEsK40ASi1cY@xxxxxxxxxxxxxxxxxxxxxx/ [4] https://lore.kernel.org/lkml/0b2697fd-7ab4-469f-83a6-ec9ebc701ba0@xxxxxxxx/ [5] https://lore.kernel.org/lkml/ZVZNh%2FPA5HiVRkeb@xxxxxxxxxxxxxxxxxxxxxx/ [6] https://lore.kernel.org/all/20240725183325.122827-1-ojeda@xxxxxxxxxx/ Changes in v5: - Addresses Sami's comments from v3 that I missed in v4 (missing early return, extra parens) v4: https://lore.kernel.org/asahi/20240924212024.540574-1-mmaurer@xxxxxxxxxx/ - Fix incorrect dot munging in PPC v3: https://lore.kernel.org/lkml/87le0w2hop.fsf@mail.lhotse/T/ - Split up the module verification refactor into smaller patches, per Greg K-H's suggestion. v2: https://lore.kernel.org/all/20231118025748.2778044-1-mmaurer@xxxxxxxxxx/ - Add loading/verification refactor before modifying, per Luis's request v1: https://lore.kernel.org/rust-for-linux/20231115185858.2110875-1-mmaurer@xxxxxxxxxx/ Matthew Maurer (16): module: Take const arg in validate_section_offset module: Factor out elf_validity_ehdr module: Factor out elf_validity_cache_sechdrs module: Factor out elf_validity_cache_secstrings module: Factor out elf_validity_cache_index_info module: Factor out elf_validity_cache_index_mod module: Factor out elf_validity_cache_index_sym module: Factor out elf_validity_cache_index_str module: Group section index calculations together module: Factor out elf_validity_cache_strtab module: Additional validation in elf_validity_cache_strtab module: Reformat struct for code style export_report: Rehabilitate script modules: Support extended MODVERSIONS info modpost: Produce extended modversion information export_report: Use new version info format arch/powerpc/kernel/module_64.c | 23 +- kernel/module/internal.h | 18 +- kernel/module/main.c | 647 ++++++++++++++++++++++++-------- kernel/module/version.c | 45 +++ scripts/export_report.pl | 17 +- scripts/mod/modpost.c | 39 +- 6 files changed, 628 insertions(+), 161 deletions(-) -- 2.46.1.824.gd892dcdcdd-goog
