| Age | Commit message (Collapse) | Author |
|---|
|
Add two tracepoints to the CONFIG_KAPI_RUNTIME_CHECKS syscall validation
path so the framework's behavior can be observed without the noise and
loss of pr_warn_ratelimited():
kapi_syscall_enter - the spec name, the raw argument values, and a
rendered "name=value" list of the specified
parameters (pointer-like values in hex, signed
integers and file descriptors in decimal)
kapi_syscall_exit - the spec name, the return value, and whether it
matched the specification (spec_match)
Both fire only for syscalls that have a KAPI specification and live
inside the existing CONFIG_KAPI_RUNTIME_CHECKS region, so they exist
exactly when the runtime checks do; they compile to no-ops without
CONFIG_TRACEPOINTS and stay dormant until enabled. The parameter list
is rendered only when the enter tracepoint is enabled.
kapi_syscall_exit is also emitted on the parameter-validation rejection
path -- where the validator returns -EINVAL and the real handler is
skipped -- with spec_match=0, so every kapi_syscall_enter has a matching
exit.
Assisted-by: LLM
Signed-off-by: Sasha Levin <sashal@kernel.org>
|
|
Add a debugfs interface, enabled by CONFIG_KAPI_SPEC_DEBUGFS, to expose
kernel API specifications at runtime. This allows tools and users to
query the complete API specifications through the debugfs filesystem.
The interface provides:
- /sys/kernel/debug/kapi/list - lists all available API specifications
- /sys/kernel/debug/kapi/specs/<name> - detailed info for each API
- /sys/kernel/debug/kapi/specs-json/<name> - the same spec as JSON
Each specification file includes:
- Function name, version, and descriptions
- Execution context requirements and flags
- Parameter details with types, flags, and constraints
- Return value specifications and success conditions
- Error codes with descriptions and conditions
- Locking requirements and constraints
- Signal handling specifications
- Examples and notes
This enables runtime introspection of kernel APIs for documentation
tools, static analyzers, and debugging purposes.
Assisted-by: LLM
Signed-off-by: Sasha Levin <sashal@kernel.org>
|
|
Add a framework for formally documenting kernel APIs with inline
specifications. This framework provides:
- Structured API documentation with parameter specifications, return
values, error conditions, and execution context requirements
- Runtime validation capabilities for debugging
(CONFIG_KAPI_RUNTIME_CHECKS)
- Support for both internal kernel APIs and system calls
The framework stores specifications in a dedicated ELF section and
provides infrastructure for:
- Runtime querying of API documentation
- Integration with existing SYSCALL_DEFINE macros
A KUnit suite (CONFIG_KAPI_KUNIT_TEST) covers registration, lookup,
parameter and return value validation, and JSON export.
No specifications are added here; subsequent patches add them for
individual syscalls. With CONFIG_KAPI_SPEC=n the SYSCALL_DEFINEx()
expansion is unchanged. CONFIG_KAPI_RUNTIME_CHECKS is a debug option:
a syscall whose arguments violate its specification returns -EINVAL
without running.
Assisted-by: LLM
Signed-off-by: Sasha Levin <sashal@kernel.org>
|
