user/sven/linux.git/include/linux/compiler.h, branch v6.10.7

compiler.h: Add missing quote in macro comment

2024-04-09T16:06:50Z

Add a missing doublequote in the __is_constexpr() macro comment. Signed-off-by: Thorsten Blum Signed-off-by: Linus Torvalds

Merge tag 'loongarch-6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson

2024-03-22T17:22:45Z

Pull LoongArch updates from Huacai Chen: - Add objtool support for LoongArch - Add ORC stack unwinder support for LoongArch - Add kernel livepatching support for LoongArch - Select ARCH_HAS_CURRENT_STACK_POINTER in Kconfig - Select HAVE_ARCH_USERFAULTFD_MINOR in Kconfig - Some bug fixes and other small changes * tag 'loongarch-6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson: LoongArch/crypto: Clean up useless assignment operations LoongArch: Define the __io_aw() hook as mmiowb() LoongArch: Remove superfluous flush_dcache_page() definition LoongArch: Move {dmw,tlb}_virt_to_page() definition to page.h LoongArch: Change __my_cpu_offset definition to avoid mis-optimization LoongArch: Select HAVE_ARCH_USERFAULTFD_MINOR in Kconfig LoongArch: Select ARCH_HAS_CURRENT_STACK_POINTER in Kconfig LoongArch: Add kernel livepatching support LoongArch: Add ORC stack unwinder support objtool: Check local label in read_unwind_hints() objtool: Check local label in add_dead_ends() objtool/LoongArch: Enable orc to be built objtool/x86: Separate arch-specific and generic parts objtool/LoongArch: Implement instruction decoder objtool/LoongArch: Enable objtool to be built

Merge tag 'hardening-v6.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

2024-03-12T21:49:30Z

Pull hardening updates from Kees Cook: "As is pretty normal for this tree, there are changes all over the place, especially for small fixes, selftest improvements, and improved macro usability. Some header changes ended up landing via this tree as they depended on the string header cleanups. Also, a notable set of changes is the work for the reintroduction of the UBSAN signed integer overflow sanitizer so that we can continue to make improvements on the compiler side to make this sanitizer a more viable future security hardening option. Summary: - string.h and related header cleanups (Tanzir Hasan, Andy Shevchenko) - VMCI memcpy() usage and struct_size() cleanups (Vasiliy Kovalev, Harshit Mogalapalli) - selftests/powerpc: Fix load_unaligned_zeropad build failure (Michael Ellerman) - hardened Kconfig fragment updates (Marco Elver, Lukas Bulwahn) - Handle tail call optimization better in LKDTM (Douglas Anderson) - Use long form types in overflow.h (Andy Shevchenko) - Add flags param to string_get_size() (Andy Shevchenko) - Add Coccinelle script for potential struct_size() use (Jacob Keller) - Fix objtool corner case under KCFI (Josh Poimboeuf) - Drop 13 year old backward compat CAP_SYS_ADMIN check (Jingzi Meng) - Add str_plural() helper (Michal Wajdeczko, Kees Cook) - Ignore relocations in .notes section - Add comments to explain how __is_constexpr() works - Fix m68k stack alignment expectations in stackinit Kunit test - Convert string selftests to KUnit - Add KUnit tests for fortified string functions - Improve reporting during fortified string warnings - Allow non-type arg to type_max() and type_min() - Allow strscpy() to be called with only 2 arguments - Add binary mode to leaking_addresses scanner - Various small cleanups to leaking_addresses scanner - Adding wrapping_*() arithmetic helper - Annotate initial signed integer wrap-around in refcount_t - Add explicit UBSAN section to MAINTAINERS - Fix UBSAN self-test warnings - Simplify UBSAN build via removal of CONFIG_UBSAN_SANITIZE_ALL - Reintroduce UBSAN's signed overflow sanitizer" * tag 'hardening-v6.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: (51 commits) selftests/powerpc: Fix load_unaligned_zeropad build failure string: Convert helpers selftest to KUnit string: Convert selftest to KUnit sh: Fix build with CONFIG_UBSAN=y compiler.h: Explain how __is_constexpr() works overflow: Allow non-type arg to type_max() and type_min() VMCI: Fix possible memcpy() run-time warning in vmci_datagram_invoke_guest_handler() lib/string_helpers: Add flags param to string_get_size() x86, relocs: Ignore relocations in .notes section objtool: Fix UNWIND_HINT_{SAVE,RESTORE} across basic blocks overflow: Use POD in check_shl_overflow() lib: stackinit: Adjust target string to 8 bytes for m68k sparc: vdso: Disable UBSAN instrumentation kernel.h: Move lib/cmdline.c prototypes to string.h leaking_addresses: Provide mechanism to scan binary files leaking_addresses: Ignore input device status lines leaking_addresses: Use File::Temp for /tmp files MAINTAINERS: Update LEAKING_ADDRESSES details fortify: Improve buffer overflow reporting fortify: Add KUnit tests for runtime overflows ...

LoongArch: Add ORC stack unwinder support

2024-03-11T14:23:47Z

The kernel CONFIG_UNWINDER_ORC option enables the ORC unwinder, which is similar in concept to a DWARF unwinder. The difference is that the format of the ORC data is much simpler than DWARF, which in turn allows the ORC unwinder to be much simpler and faster. The ORC data consists of unwind tables which are generated by objtool. After analyzing all the code paths of a .o file, it determines information about the stack state at each instruction address in the file and outputs that information to the .orc_unwind and .orc_unwind_ip sections. The per-object ORC sections are combined at link time and are sorted and post-processed at boot time. The unwinder uses the resulting data to correlate instruction addresses with their stack states at run time. Most of the logic are similar with x86, in order to get ra info before ra is saved into stack, add ra_reg and ra_offset into orc_entry. At the same time, modify some arch-specific code to silence the objtool warnings. Co-developed-by: Jinyang He Signed-off-by: Jinyang He Co-developed-by: Youling Tang Signed-off-by: Youling Tang Signed-off-by: Tiezhu Yang Signed-off-by: Huacai Chen

compiler.h: Explain how __is_constexpr() works

2024-03-02T00:03:32Z

The __is_constexpr() macro is dark magic. Shed some light on it with a comment to explain how and why it works. Acked-by: Gustavo A. R. Silva Reviewed-by: Jani Nikula Link: https://lore.kernel.org/r/20240301044428.work.411-kees@kernel.org Signed-off-by: Kees Cook

Merge tag 'v6.8-rc4' into x86/percpu, to resolve conflicts and refresh the branch

2024-02-14T09:45:07Z

Conflicts: arch/x86/include/asm/percpu.h arch/x86/include/asm/text-patching.h Signed-off-by: Ingo Molnar

x86/percpu: Introduce const-qualified const_pcpu_hot to micro-optimize code generation

2023-10-23T09:27:35Z

Some variables in pcpu_hot, currently current_task and top_of_stack are actually per-thread variables implemented as per-CPU variables and thus stable for the duration of the respective task. There is already an attempt to eliminate redundant reads from these variables using this_cpu_read_stable() asm macro, which hides the dependency on the read memory address. However, the compiler has limited ability to eliminate asm common subexpressions, so this approach results in a limited success. The solution is to allow more aggressive elimination by aliasing pcpu_hot into a const-qualified const_pcpu_hot, and to read stable per-CPU variables from this constant copy. The current per-CPU infrastructure does not support reads from const-qualified variables. However, when the compiler supports segment qualifiers, it is possible to declare the const-aliased variable in the relevant named address space. The compiler considers access to the variable, declared in this way, as a read from a constant location, and will optimize reads from the variable accordingly. By implementing constant-qualified const_pcpu_hot, the compiler can eliminate redundant reads from the constant variables, reducing the number of loads from current_task from 3766 to 3217 on a test build, a -14.6% reduction. The reduction of loads translates to the following code savings: text data bss dec hex filename 25,477,353 4389456 808452 30675261 1d4113d vmlinux-old.o 25,476,074 4389440 808452 30673966 1d40c2e vmlinux-new.o representing a code size reduction of -1279 bytes. [ mingo: Updated the changelog, EXPORT(const_pcpu_hot). ] Co-developed-by: Nadav Amit Signed-off-by: Nadav Amit Signed-off-by: Uros Bizjak Signed-off-by: Ingo Molnar Link: https://lore.kernel.org/r/20231020162004.135244-1-ubizjak@gmail.com

compiler.h: move __is_constexpr() to compiler.h

2023-10-18T21:43:22Z

Prior to f747e6667ebb2 __is_constexpr() was in its only user minmax.h. That commit moved it to const.h - but that file just defines ULL(x) and UL(x) so that constants can be defined for .S and .c files. So apart from the word 'const' it wasn't really a good location. Instead move the definition to compiler.h just before the similar is_signed_type() and is_unsigned_type(). This may not be a good long-term home, but the three definitions belong together. Link: https://lkml.kernel.org/r/2a6680bbe2e84459816a113730426782@AcuMS.aculab.com Signed-off-by: David Laight Reviewed-by: Kees Cook Cc: Arnd Bergmann Cc: Bart Van Assche Cc: Nathan Chancellor Cc: Nick Desaulniers Cc: Rasmus Villemoes Cc: Steven Rostedt (Google) Signed-off-by: Andrew Morton

compiler.h: unify __UNIQUE_ID

2023-10-04T17:41:56Z

commit 6f33d58794ef ("__UNIQUE_ID()") added a fallback definition of __UNIQUE_ID because gcc 4.2 and older did not support __COUNTER__. Also, this commit is effectively a revert of commit b41c29b0527c ("Kbuild: provide a __UNIQUE_ID for clang") which mentions clang 2.6+ supporting __COUNTER__. Documentation/process/changes.rst currently lists the minimum supported version of these compilers as: - gcc: 5.1 - clang: 11.0.0 It should be safe to say that __COUNTER__ is well supported by this point. Link: https://lkml.kernel.org/r/20230831-unique_id-v1-1-28bacd18eb1d@google.com Signed-off-by: Nick Desaulniers Cc: Arnd Bergmann Cc: Jan Beulich Cc: Luc Van Oostenryck Cc: Michal rarek Cc: Nathan Chancellor Cc: Paul Russel Cc: Tom Rix Signed-off-by: Andrew Morton

tracing: make ftrace_likely_update() declaration visible

2023-05-17T16:36:46Z

This function is only used when CONFIG_TRACE_BRANCH_PROFILING is set and DISABLE_BRANCH_PROFILING is not set, and the declaration is hidden behind this combination of tests. But that causes a warning when building with CONFIG_TRACING_BRANCHES, since that sets DISABLE_BRANCH_PROFILING for the tracing code, and the declaration is thus hidden: kernel/trace/trace_branch.c:205:6: error: no previous prototype for 'ftrace_likely_update' [-Werror=missing-prototypes] Move the declaration out of the #ifdef to avoid the warning. Signed-off-by: Arnd Bergmann Signed-off-by: Linus Torvalds