user/sven/linux.git/scripts/Makefile.extrawarn, branch v6.6.14

extrawarn: move -Wrestrict into W=1 warnings

2023-08-20T05:16:59Z

There are few of these, so enable them whenever W=1 is enabled. Signed-off-by: Arnd Bergmann Signed-off-by: Masahiro Yamada

extrawarn: enable format and stringop overflow warnings in W=1

2023-08-20T05:16:59Z

The stringop and format warnings got disabled globally when they were newly introduced in commit bd664f6b3e376 ("disable new gcc-7.1.1 warnings for now"), 217c3e0196758 ("disable stringop truncation warnings for now") and 5a76021c2eff7 ("gcc-10: disable 'stringop-overflow' warning for now"). In all cases, the sentiment at the time was that the warnings are useful, and we actually addressed a number of real bugs based on them, but we never managed to eliminate them all because even the build bots using W=1 builds only see the -Wstringop-truncation warnings that are enabled at that level. Move these into the W=1 section to give them a larger build coverage and actually eliminate them over time. Signed-off-by: Arnd Bergmann Signed-off-by: Masahiro Yamada

kbuild: avoid duplicate warning options

2023-08-20T05:16:57Z

Some warning options are disabled at one place and then conditionally re-enabled later in scripts/Makefile.extrawarn. For consistency, rework this file so each of those warnings only gets etiher enabled or disabled based on the W= flags but not both. Signed-off-by: Arnd Bergmann Signed-off-by: Masahiro Yamada

kbuild: consolidate warning flags in scripts/Makefile.extrawarn

2023-08-20T05:16:54Z

Warning options are enabled and disabled in inconsistent ways and inconsistent locations. Start rearranging those by moving all options into Makefile.extrawarn. This should not change any behavior, but makes sure we can group them in a way that ensures that each warning that got temporarily disabled is turned back on at an appropriate W=1 level later on. Signed-off-by: Arnd Bergmann Signed-off-by: Masahiro Yamada

kbuild: add -Wundef to KBUILD_CPPFLAGS for W=1 builds

2022-12-11T08:28:32Z

The use of an undefined macro in an #if directive is warned, but only in *.c files. No warning from other files such as *.S, *.lds.S. Since -Wundef is a preprocessor-related warning, it should be added to KBUILD_CPPFLAGS instead of KBUILD_CFLAGS. My previous attempt [1] uncovered several issues. I could not finish fixing them all. This commit adds -Wundef to KBUILD_CPPFLAGS for W=1 builds in order to block new breakages. (The kbuild test robot tests with W=1) We can fix the warnings one by one. After fixing all of them, we can make it default in the top Makefile, and remove -Wundef from KBUILD_CFLAGS. [1]: https://lore.kernel.org/all/20221012180118.331005-2-masahiroy@kernel.org/ Signed-off-by: Masahiro Yamada Reviewed-by: Nathan Chancellor Reviewed-by: Nick Desaulniers

Merge tag 'kbuild-v6.1' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

2022-10-10T19:00:45Z

Pull Kbuild updates from Masahiro Yamada: - Remove potentially incomplete targets when Kbuid is interrupted by SIGINT etc in case GNU Make may miss to do that when stderr is piped to another program. - Rewrite the single target build so it works more correctly. - Fix rpm-pkg builds with V=1. - List top-level subdirectories in ./Kbuild. - Ignore auto-generated __kstrtab_* and __kstrtabns_* symbols in kallsyms. - Avoid two different modules in lib/zstd/ having shared code, which potentially causes building the common code as build-in and modular back-and-forth. - Unify two modpost invocations to optimize the build process. - Remove head-y syntax in favor of linker scripts for placing particular sections in the head of vmlinux. - Bump the minimal GNU Make version to 3.82. - Clean up misc Makefiles and scripts. * tag 'kbuild-v6.1' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (41 commits) docs: bump minimal GNU Make version to 3.82 ia64: simplify esi object addition in Makefile Revert "kbuild: Check if linker supports the -X option" kbuild: rebuild .vmlinux.export.o when its prerequisite is updated kbuild: move modules.builtin(.modinfo) rules to Makefile.vmlinux_o zstd: Fixing mixed module-builtin objects kallsyms: ignore __kstrtab_* and __kstrtabns_* symbols kallsyms: take the input file instead of reading stdin kallsyms: drop duplicated ignore patterns from kallsyms.c kbuild: reuse mksysmap output for kallsyms mksysmap: update comment about __crc_* kbuild: remove head-y syntax kbuild: use obj-y instead extra-y for objects placed at the head kbuild: hide error checker logs for V=1 builds kbuild: re-run modpost when it is updated kbuild: unify two modpost invocations kbuild: move vmlinux.o rule to the top Makefile kbuild: move .vmlinux.objs rule to Makefile.modpost kbuild: list sub-directories in ./Kbuild Makefile.compiler: replace cc-ifversion with compiler-specific macros ...

Merge tag 'hardening-v6.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

2022-10-04T00:24:22Z

Pull kernel hardening updates from Kees Cook: "Most of the collected changes here are fixes across the tree for various hardening features (details noted below). The most notable new feature here is the addition of the memcpy() overflow warning (under CONFIG_FORTIFY_SOURCE), which is the next step on the path to killing the common class of "trivially detectable" buffer overflow conditions (i.e. on arrays with sizes known at compile time) that have resulted in many exploitable vulnerabilities over the years (e.g. BleedingTooth). This feature is expected to still have some undiscovered false positives. It's been in -next for a full development cycle and all the reported false positives have been fixed in their respective trees. All the known-bad code patterns we could find with Coccinelle are also either fixed in their respective trees or in flight. The commit message in commit 54d9469bc515 ("fortify: Add run-time WARN for cross-field memcpy()") for the feature has extensive details, but I'll repeat here that this is a warning _only_, and is not intended to actually block overflows (yet). The many patches fixing array sizes and struct members have been landing for several years now, and we're finally able to turn this on to find any remaining stragglers. Summary: Various fixes across several hardening areas: - loadpin: Fix verity target enforcement (Matthias Kaehlcke). - zero-call-used-regs: Add missing clobbers in paravirt (Bill Wendling). - CFI: clean up sparc function pointer type mismatches (Bart Van Assche). - Clang: Adjust compiler flag detection for various Clang changes (Sami Tolvanen, Kees Cook). - fortify: Fix warnings in arch-specific code in sh, ARM, and xen. Improvements to existing features: - testing: improve overflow KUnit test, introduce fortify KUnit test, add more coverage to LKDTM tests (Bart Van Assche, Kees Cook). - overflow: Relax overflow type checking for wider utility. New features: - string: Introduce strtomem() and strtomem_pad() to fill a gap in strncpy() replacement needs. - um: Enable FORTIFY_SOURCE support. - fortify: Enable run-time struct member memcpy() overflow warning" * tag 'hardening-v6.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: (27 commits) Makefile.extrawarn: Move -Wcast-function-type-strict to W=1 hardening: Remove Clang's enable flag for -ftrivial-auto-var-init=zero sparc: Unbreak the build x86/paravirt: add extra clobbers with ZERO_CALL_USED_REGS enabled x86/paravirt: clean up typos and grammaros fortify: Convert to struct vs member helpers fortify: Explicitly check bounds are compile-time constants x86/entry: Work around Clang __bdos() bug ARM: decompressor: Include .data.rel.ro.local fortify: Adjust KUnit test for modular build sh: machvec: Use char[] for section boundaries kunit/memcpy: Avoid pathological compile-time string size lib: Improve the is_signed_type() kunit test LoadPin: Require file with verity root digests to have a header dm: verity-loadpin: Only trust verity targets with enforcement LoadPin: Fix Kconfig doc about format of file with verity digests um: Enable FORTIFY_SOURCE lkdtm: Update tests for memcpy() run-time warnings fortify: Add run-time WARN for cross-field memcpy() fortify: Use SIZE_MAX instead of (size_t)-1 ...

Makefile.extrawarn: Move -Wcast-function-type-strict to W=1

2022-10-01T14:46:05Z

We enable -Wcast-function-type globally in the kernel to warn about mismatching types in function pointer casts. Compilers currently warn only about ABI incompability with this flag, but Clang 16 will enable a stricter version of the check by default that checks for an exact type match. This will be very noisy in the kernel, so disable -Wcast-function-type-strict without W=1 until the new warnings have been addressed. Cc: stable@vger.kernel.org Link: https://reviews.llvm.org/D134831 Link: https://github.com/ClangBuiltLinux/linux/issues/1724 Suggested-by: Nathan Chancellor Signed-off-by: Sami Tolvanen Signed-off-by: Kees Cook Link: https://lore.kernel.org/r/20220930203310.4010564-1-samitolvanen@google.com

Makefile.compiler: replace cc-ifversion with compiler-specific macros

2022-09-28T19:40:16Z

cc-ifversion is GCC specific. Replace it with compiler specific variants. Update the users of cc-ifversion to use these new macros. Link: https://github.com/ClangBuiltLinux/linux/issues/350 Link: https://lore.kernel.org/llvm/CAGG=3QWSAUakO42kubrCap8fp-gm1ERJJAYXTnP1iHk_wrH=BQ@mail.gmail.com/ Suggested-by: Bill Wendling Reviewed-by: Nathan Chancellor Signed-off-by: Nick Desaulniers Signed-off-by: Masahiro Yamada

Makefile.extrawarn: re-enable -Wformat for clang; take 2

2022-09-04T18:15:50Z

-Wformat was recently re-enabled for builds with clang, then quickly re-disabled, due to concerns stemming from the frequency of default argument promotion related warning instances. commit 258fafcd0683 ("Makefile.extrawarn: re-enable -Wformat for clang") commit 21f9c8a13bb2 ("Revert "Makefile.extrawarn: re-enable -Wformat for clang"") ISO WG14 has ratified N2562 to address default argument promotion explicitly for printf, as part of the upcoming ISO C2X standard. The behavior of clang was changed in clang-16 to not warn for the cited cases in all language modes. Add a version check, so that users of clang-16 now get the full effect of -Wformat. For older clang versions, re-enable flags under the -Wformat group that way users still get some useful checks related to format strings, without noisy default argument promotion warnings. I intentionally omitted -Wformat-y2k and -Wformat-security from being re-enabled, which are also part of -Wformat in clang-16. Link: https://github.com/ClangBuiltLinux/linux/issues/378 Link: https://github.com/llvm/llvm-project/issues/57102 Link: https://www.open-std.org/jtc1/sc22/wg14/www/docs/n2562.pdf Suggested-by: Justin Stitt Suggested-by: Nathan Chancellor Suggested-by: Youngmin Nam Signed-off-by: Nick Desaulniers Reviewed-by: Masahiro Yamada Reviewed-by: Nathan Chancellor Signed-off-by: Linus Torvalds