diff options
Diffstat (limited to 'internal')
| -rw-r--r-- | internal/generate/family.go | 33 | ||||
| -rw-r--r-- | internal/generate/family_test.go | 18 |
2 files changed, 50 insertions, 1 deletions
diff --git a/internal/generate/family.go b/internal/generate/family.go index dafbe13..daa7ab8 100644 --- a/internal/generate/family.go +++ b/internal/generate/family.go @@ -101,7 +101,38 @@ var syscallFamilies = map[string]SyscallFamily{ "ioprio_get": FamilyProcess, "ioprio_set": FamilyProcess, "kcmp": FamilyProcess, "personality": FamilyProcess, "pivot_root": FamilyProcess, "prctl": FamilyProcess, "prlimit64": FamilyProcess, "reboot": FamilyProcess, - "restart_syscall": FamilyProcess, "set_tid_address": FamilyProcess, + "restart_syscall": FamilyProcess, + // Boundary rule for the Process vs Misc split of PER-THREAD POINTER + // REGISTRATION syscalls (keep consistent — distinct from the futex IPC-vs- + // Misc rule documented in the futex block above): + // + // - set_tid_address(2) stays Process. Although it "merely" hands the + // kernel a tidptr it consults later, that pointer is the kernel's + // primary THREAD-EXIT notification mechanism: it sets clear_child_tid, + // which the kernel zeroes and FUTEX_WAKEs at thread teardown. The C + // runtime sets it (via clone(2) CLONE_CHILD_CLEARTID, or this syscall) + // for essentially every thread, the call returns the caller's thread ID + // (a pid_t, like gettid/getpid), and it is mandatory thread-lifecycle + // plumbing. It therefore belongs with the core process/thread lifecycle + // cluster — clone/clone3/fork/vfork/exit/exit_group/wait4/waitid/gettid + // — not with optional opt-in features. + // + // - rseq(2) and set_robust_list/get_robust_list(2) stay Misc (absent from + // this table by design; see ClassifySyscallFamily's default and the + // assertions in family_test.go). They register OPTIONAL, opt-in + // per-thread feature areas: rseq a restartable-sequences scheduling + // optimization, robust_list a futex-cleanup list a program only uses if + // it opts into robust mutexes. They are not part of the mandatory + // thread-lifecycle path and a thread runs fine without ever calling + // them. + // + // The split axis here is mandatory-thread-lifecycle vs optional-opt-in- + // feature, NOT pointer-registration-vs-operation (which would lump all + // three into Misc). Do not move set_tid_address to Misc for "registration + // consistency" with rseq/robust_list: registration is the surface form, but + // set_tid_address is core thread lifecycle while the others are optional + // features. + "set_tid_address": FamilyProcess, "setfsuid": FamilyProcess, "setfsgid": FamilyProcess, "setgid": FamilyProcess, "setgroups": FamilyProcess, "setns": FamilyProcess, "setpgid": FamilyProcess, "setpriority": FamilyProcess, "setregid": FamilyProcess, "setresgid": FamilyProcess, diff --git a/internal/generate/family_test.go b/internal/generate/family_test.go index 4bff095..ee92740 100644 --- a/internal/generate/family_test.go +++ b/internal/generate/family_test.go @@ -166,6 +166,24 @@ func TestClassifySyscallFamily(t *testing.T) { {"sys_exit_rseq", FamilyMisc}, {"sys_enter_set_robust_list", FamilyMisc}, {"sys_enter_get_robust_list", FamilyMisc}, + // set_tid_address(2) is the deliberate counterpoint to the + // rseq/robust_list cluster above: it shares the surface form + // ("per-thread registration of a pointer the kernel consults later") + // but stays Process, NOT Misc. WHY: the tidptr it registers is + // clear_child_tid — the kernel's primary thread-EXIT notification + // mechanism (zeroed + FUTEX_WAKEd at thread teardown), set by the C + // runtime for essentially every thread (clone(2) CLONE_CHILD_CLEARTID), + // and the call returns the caller's thread ID like gettid/getpid. It is + // mandatory thread-lifecycle plumbing and belongs with + // clone/fork/exit/gettid, whereas rseq (scheduling optimization) and + // robust_list (opt-in futex cleanup) are OPTIONAL per-thread features a + // thread runs fine without. The Process-vs-Misc axis here is + // mandatory-lifecycle vs optional-opt-in-feature, not registration-vs- + // operation. Assert enter+exit so a stray move to Misc trips this test. + // See the Process-vs-Misc boundary block in family.go and keep in sync + // with the Process list in docs/syscall-tracing-plan.md. + {"sys_enter_set_tid_address", FamilyProcess}, + {"sys_exit_set_tid_address", FamilyProcess}, // sysinfo(2) returns overall system statistics (memory/swap usage and // load averages) into a single userspace struct sysinfo *info pointer // (an output buffer, not an fd/path). It is not in the explicit family |