user/sven/linux.git/scripts/mod, branch v6.1.21

modpost: fix module versioning when a symbol lacks valid CRC

2022-08-20T17:47:36Z

Since commit 7b4537199a4a ("kbuild: link symbol CRCs at final link, removing CONFIG_MODULE_REL_CRCS"), module versioning is broken on some architectures. Loading a module fails with "disagrees about version of symbol module_layout". On such architectures (e.g. ARCH=sparc build with sparc64_defconfig), modpost shows a warning, like follows: WARNING: modpost: EXPORT symbol "_mcount" [vmlinux] version generation failed, symbol will not be versioned. Is "_mcount" prototyped in ? Previously, it was a harmless warning (CRC check was just skipped), but now wrong CRCs are used for comparison because invalid CRCs are just skipped. $ sparc64-linux-gnu-nm -n vmlinux [snip] 0000000000c2cea0 r __ksymtab__kstrtol 0000000000c2ceb8 r __ksymtab__kstrtoul 0000000000c2ced0 r __ksymtab__local_bh_enable 0000000000c2cee8 r __ksymtab__mcount 0000000000c2cf00 r __ksymtab__printk 0000000000c2cf18 r __ksymtab__raw_read_lock 0000000000c2cf30 r __ksymtab__raw_read_lock_bh [snip] 0000000000c53b34 D __crc__kstrtol 0000000000c53b38 D __crc__kstrtoul 0000000000c53b3c D __crc__local_bh_enable 0000000000c53b40 D __crc__printk 0000000000c53b44 D __crc__raw_read_lock 0000000000c53b48 D __crc__raw_read_lock_bh Please notice __crc__mcount is missing here. When the module subsystem looks up a CRC that comes after, it results in reading out a wrong address. For example, when __crc__printk is needed, the module subsystem reads 0xc53b44 instead of 0xc53b40. All CRC entries must be output for correct index accessing. Invalid CRCs will be unused, but are needed to keep the one-to-one mapping between __ksymtab_* and __crc_*. The best is to fix all modpost warnings, but several warnings are still remaining on less popular architectures. Fixes: 7b4537199a4a ("kbuild: link symbol CRCs at final link, removing CONFIG_MODULE_REL_CRCS") Reported-by: matoro Signed-off-by: Masahiro Yamada Tested-by: matoro

Merge tag 'kbuild-v5.20' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

2022-08-10T17:40:41Z

Pull Kbuild updates from Masahiro Yamada: - Remove the support for -O3 (CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE_O3) - Fix error of rpm-pkg cross-builds - Support riscv for checkstack tool - Re-enable -Wformwat warnings for Clang - Clean up modpost, Makefiles, and misc scripts * tag 'kbuild-v5.20' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (30 commits) modpost: remove .symbol_white_list field entirely modpost: remove unneeded .symbol_white_list initializers modpost: add PATTERNS() helper macro modpost: shorten warning messages in report_sec_mismatch() Revert "Kbuild, lto, workaround: Don't warn for initcall_reference in modpost" modpost: use more reliable way to get fromsec in section_rel(a)() modpost: add array range check to sec_name() modpost: refactor get_secindex() kbuild: set EXIT trap before creating temporary directory modpost: remove unused Elf_Sword macro Makefile.extrawarn: re-enable -Wformat for clang kbuild: add dtbs_prepare target kconfig: Qt5: tell the user which packages are required modpost: use sym_get_data() to get module device_table data modpost: drop executable ELF support checkstack: add riscv support for scripts/checkstack.pl kconfig: shorten the temporary directory name for cc-option scripts: headers_install.sh: Update config leak ignore entries kbuild: error out if $(INSTALL_MOD_PATH) contains % or : kbuild: error out if $(KBUILD_EXTMOD) contains % or : ...

modpost: remove .symbol_white_list field entirely

2022-08-04T11:32:13Z

It is not so useful to have symbol whitelists in arrays. With this over-engineering, the code is difficult to follow. Let's do it more directly, and collect the relevant code to one place. Signed-off-by: Masahiro Yamada

modpost: remove unneeded .symbol_white_list initializers

2022-08-04T11:32:13Z

The ->symbol_white_list field is referenced in secref_whitelist(), only when 'fromsec' is data_sections. /* Check for pattern 2 */ if (match(tosec, init_exit_sections) && match(fromsec, data_sections) && match(fromsym, mismatch->symbol_white_list)) return 0; If .fromsec is not data sections, the .symbol_white_list member is not used by anyone. Signed-off-by: Masahiro Yamada

modpost: add PATTERNS() helper macro

2022-08-04T11:32:13Z

This will be useful to define a NULL-terminated array inside a function call. Currently, string arrays passed to match() are defined in separate places: static const char *const init_sections[] = { ALL_INIT_SECTIONS, NULL }; static const char *const text_sections[] = { ALL_TEXT_SECTIONS, NULL }; static const char *const optim_symbols[] = { "*.constprop.*", NULL }; ... /* Check for pattern 5 */ if (match(fromsec, text_sections) && match(tosec, init_sections) && match(fromsym, optim_symbols)) return 0; With the new helper macro, you can list the patterns directly in the function call, like this: /* Check for pattern 5 */ if (match(fromsec, PATTERNS(ALL_TEXT_SECTIONS)) && match(tosec, PATTERNS(ALL_INIT_SECTIONS)) && match(fromsym, PATTERNS("*.contprop.*"))) return 0; Signed-off-by: Masahiro Yamada

modpost: shorten warning messages in report_sec_mismatch()

2022-08-04T11:32:13Z

Each section mismatch results in long warning messages. Too much. Make each warning fit in one line, and remove a lot of messy code. Signed-off-by: Masahiro Yamada

Revert "Kbuild, lto, workaround: Don't warn for initcall_reference in modpost"

2022-08-04T11:27:17Z

This reverts commit 77ab21adae509c5540956729e2d03bc1a59bc82a. Even after 8 years later, GCC LTO has not been upstreamed. Also, it said "This is a workaround". If this is needed in the future, it should be added in a proper way. Signed-off-by: Masahiro Yamada Reviewed-by: Nick Desaulniers Acked-by: Jiri Slaby

modpost: use more reliable way to get fromsec in section_rel(a)()

2022-08-03T13:58:10Z

The section name of Rel and Rela starts with ".rel" and ".rela" respectively (but, I do not know whether this is specification or convention). For example, ".rela.text" holds relocation entries applied to the ".text" section. So, the code chops the ".rel" or ".rela" prefix to get the name of the section to which the relocation applies. However, I do not like to skip 4 or 5 bytes blindly because it is potential memory overrun. The ELF specification provides a more reliable way to do this. - The sh_info field holds extra information, whose interpretation depends on the section type - If the section type is SHT_REL or SHT_RELA, the sh_info field holds the section header index of the section to which the relocation applies. Signed-off-by: Masahiro Yamada

modpost: add array range check to sec_name()

2022-08-03T13:58:10Z

The section index is always positive, so the argument, secindex, should be unsigned. Also, inserted the array range check. If sym->st_shndx is a special section index (between SHN_LORESERVE and SHN_HIRESERVE), there is no corresponding section header. For example, if a symbol specifies an absolute value, sym->st_shndx is SHN_ABS (=0xfff1). The current users do not cause the out-of-range access of info->sechddrs[], but it is better to avoid such a pitfall. Signed-off-by: Masahiro Yamada

modpost: refactor get_secindex()

2022-08-03T13:56:46Z

SPECIAL() is only used in get_secindex(). Squash it. Make the code more readable with more comments. Signed-off-by: Masahiro Yamada