fix(process): align wait and ptrace child semantics#1983
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fslongjin merged 2 commits intoJun 22, 2026
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Refactor wait child selection away from the kill-only PID converter and introduce a wait-specific selector that models wait4 and waitid rules directly. This keeps P_ALL, P_PID, P_PGID and the current P_PIDFD boundary in the wait layer instead of leaking waitid semantics into sys_kill. Split natural-child and ptrace-child handling into explicit wait relations. Natural P_PID waits now resolve through the thread-group leader while ptrace waits resolve by task PID, matching Linux's TGID/PID split. The scan path also handles __WCLONE, __WALL and __WNOTHREAD without relying on test-specific shortcuts. Add a small ptrace relation module for PTRACE_TRACEME, tracee ownership, relation cleanup and wait-side checks. The relation is protected by a shared lock so wait cannot observe half-published ptrace state, and TRACEME uses the actual fork parent when a worker thread creates the child. Tighten event reporting and reaping. Zombie ownership is acquired before user-visible return data is filled, stopped and continued notifications are consumed with a single sighand lock operation, and zombie group leaders with live subthreads stay waitable without being reaped early. Extend wait_rusage dunitests to cover ptrace TRACEME, repeated TRACEME denial, __WNOTHREAD behavior, delayed group leader reaping, natural TID wait rejection, waitid option filtering and the current negative P_PIDFD errno boundary. Signed-off-by: longjin <longjin@dragonos.org>
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Remove blocklist entries now covered by wait/ptrace compatibility fixes. Signed-off-by: longjin <longjin@dragonos.org> Co-authored-by: Cursor <cursoragent@cursor.com>
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Summary
This PR refactors wait child selection and ptrace child handling to better match Linux wait semantics.
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Notes
P_PIDFD support remains an explicit future compatibility boundary beyond the currently covered errno validation. Full ptrace attach/detach and traced-stop semantics are also outside this minimal TRACEME relation change.
Related to: #1850