| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <20251218204239.4159453-1-sashal@kernel.org> Date: Thu, 18 Dec 2025 15:42:22 -0500 From: Sasha Levin <sashal@...nel.org> To: linux-api@...r.kernel.org Cc: linux-doc@...r.kernel.org, linux-kernel@...r.kernel.org, tools@...nel.org, gpaoloni@...hat.com, Sasha Levin <sashal@...nel.org> Subject: [RFC PATCH v5 00/15] Kernel API Specification Framework This proposal introduces machinery for documenting kernel APIs, addressing the long-standing challenge of maintaining stable interfaces between the kernel and user-space programs. Despite the kernel's commitment to never breaking user space, the lack of machine-readable API specifications has led to breakages and across system calls and IOCTLs. Specifications can document parameter types, valid ranges, constraints, and alignment requirements. They capture return value semantics including success conditions and error codes with their meaning. Execution context requirements, capabilities, locking constraints, signal handling behavior, and side effects can all be formally specified. These specifications live alongside the code they document and are both human-readable and machine-parseable. They can be validated at runtime when CONFIG_KAPI_RUNTIME_CHECKS is enabled, exported via debugfs for userspace tools, and extracted from either vmlinux or source code. This enables static analysis tools to verify userspace API usage at compile time, test generation based on formal specifications, consistent error handling validation, automated documentation generation, and formal verification of kernel interfaces. The implementation includes a core framework with ELF section storage, kerneldoc integration for inline specification, a debugfs interface for runtime querying, and a Rust-based extraction tool (tools/kapi) supporting JSON, RST, and plain text output formats. Example specifications are provided for async I/O, xattr, and basic file operation syscalls. The series with runtime testing enabled (CONFIG_KAPI_RUNTIME_CHECKS=y) currently survives LTP tests in a KVM VM. I am not looking for a review of the actual specs just yet. Those are LLM generated, and the main focus right now is the format of the spec rather than the individual specs. Having said that, there is a set with more syscall specs (100+) available at git://git.kernel.org/pub/scm/linux/kernel/git/sashal/linux.git branch "spec" for folks who are interested in testing it out. Changes since RFC v4: - Rebase on top of v6.19-rc1, addressing a few conflict resulting of how Documentation/ now handles python. - Moved documentation from Documentation/admin-guide/ to Documentation/dev-tools/ (Randy Dunlap) - Different examples of specs to hopefully allow for better review. - Simplified architecture support by using generic vmlinux.lds.h instead of per-architecture linker script modifications. Sasha Levin (15): kernel/api: introduce kernel API specification framework kernel/api: enable kerneldoc-based API specifications kernel/api: add debugfs interface for kernel API specifications tools/kapi: Add kernel API specification extraction tool kernel/api: add API specification for io_setup kernel/api: add API specification for io_destroy kernel/api: add API specification for io_submit kernel/api: add API specification for io_cancel kernel/api: add API specification for setxattr kernel/api: add API specification for lsetxattr kernel/api: add API specification for fsetxattr kernel/api: add API specification for sys_open kernel/api: add API specification for sys_close kernel/api: add API specification for sys_read kernel/api: add API specification for sys_write .gitignore | 1 + Documentation/dev-tools/kernel-api-spec.rst | 699 ++++++++ MAINTAINERS | 9 + fs/aio.c | 982 +++++++++- fs/open.c | 565 +++++- fs/read_write.c | 664 +++++++ fs/xattr.c | 959 ++++++++++ include/asm-generic/vmlinux.lds.h | 28 + include/linux/kernel_api_spec.h | 1597 +++++++++++++++++ include/linux/syscall_api_spec.h | 198 ++ include/linux/syscalls.h | 38 + init/Kconfig | 2 + kernel/Makefile | 3 + kernel/api/Kconfig | 55 + kernel/api/Makefile | 32 + kernel/api/kapi_debugfs.c | 358 ++++ kernel/api/kernel_api_spec.c | 1185 ++++++++++++ scripts/Makefile.build | 28 + scripts/Makefile.clean | 3 + scripts/generate_api_specs.sh | 87 + scripts/kernel-doc.py | 5 + tools/kapi/.gitignore | 4 + tools/kapi/Cargo.toml | 19 + tools/kapi/src/extractor/debugfs.rs | 442 +++++ tools/kapi/src/extractor/kerneldoc_parser.rs | 692 +++++++ tools/kapi/src/extractor/mod.rs | 464 +++++ tools/kapi/src/extractor/source_parser.rs | 213 +++ .../src/extractor/vmlinux/binary_utils.rs | 180 ++ .../src/extractor/vmlinux/magic_finder.rs | 102 ++ tools/kapi/src/extractor/vmlinux/mod.rs | 864 +++++++++ tools/kapi/src/formatter/json.rs | 468 +++++ tools/kapi/src/formatter/mod.rs | 140 ++ tools/kapi/src/formatter/plain.rs | 549 ++++++ tools/kapi/src/formatter/rst.rs | 621 +++++++ tools/kapi/src/main.rs | 116 ++ tools/lib/python/kdoc/kdoc_apispec.py | 755 ++++++++ tools/lib/python/kdoc/kdoc_output.py | 9 +- tools/lib/python/kdoc/kdoc_parser.py | 86 +- 38 files changed, 13176 insertions(+), 46 deletions(-) create mode 100644 Documentation/dev-tools/kernel-api-spec.rst create mode 100644 include/linux/kernel_api_spec.h create mode 100644 include/linux/syscall_api_spec.h create mode 100644 kernel/api/Kconfig create mode 100644 kernel/api/Makefile create mode 100644 kernel/api/kapi_debugfs.c create mode 100644 kernel/api/kernel_api_spec.c create mode 100755 scripts/generate_api_specs.sh create mode 100644 tools/kapi/.gitignore create mode 100644 tools/kapi/Cargo.toml create mode 100644 tools/kapi/src/extractor/debugfs.rs create mode 100644 tools/kapi/src/extractor/kerneldoc_parser.rs create mode 100644 tools/kapi/src/extractor/mod.rs create mode 100644 tools/kapi/src/extractor/source_parser.rs create mode 100644 tools/kapi/src/extractor/vmlinux/binary_utils.rs create mode 100644 tools/kapi/src/extractor/vmlinux/magic_finder.rs create mode 100644 tools/kapi/src/extractor/vmlinux/mod.rs create mode 100644 tools/kapi/src/formatter/json.rs create mode 100644 tools/kapi/src/formatter/mod.rs create mode 100644 tools/kapi/src/formatter/plain.rs create mode 100644 tools/kapi/src/formatter/rst.rs create mode 100644 tools/kapi/src/main.rs create mode 100644 tools/lib/python/kdoc/kdoc_apispec.py -- 2.51.0
Powered by blists - more mailing lists