Date: Wed, 22 Apr 2026 00:44:22 +0000 From: Konstantin Belousov <kib@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org Cc: GenericRikka <rikka.goering@outlook.de> Subject: git: 0f89380a3d20 - main - kern/proc: expose reaper PID and subtree root in struct kinfo_proc Message-ID: <69e819e6.1f2b1.a1a0956@gitrepo.freebsd.org>
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The branch main has been updated by kib: URL: https://cgit.FreeBSD.org/src/commit/?id=0f89380a3d208d67698f2d35afd35257e5fdbe09 commit 0f89380a3d208d67698f2d35afd35257e5fdbe09 Author: GenericRikka <rikka.goering@outlook.de> AuthorDate: 2026-04-20 23:32:49 +0000 Commit: Konstantin Belousov <kib@FreeBSD.org> CommitDate: 2026-04-21 23:36:07 +0000 kern/proc: expose reaper PID and subtree root in struct kinfo_proc Expose process reaper metadata through struct kinfo_proc so userland can reconstruct reaper hierarchies from kern.proc.all without adding a new procctl(2) operation. Two pid_t fields are added by carving 8 bytes from ki_sparestrings (46 -> 38), restoring KI_NSPARE_INT to 2 and keeping sizeof(struct kinfo_proc) unchanged: ki_reaper: PID of the owning reaper process ki_reapsubtree: PID of the direct child of the reaper that roots the subtree the process belongs to fill_kinfo_proc_pgrp() populates both fields under proctree_lock. kvm_proclist() is updated for crash dump consumers. The freebsd32 compat struct and freebsd32_kinfo_proc_out() are updated accordingly. PR: 293871 Reviewed by: kib MFC after: 1 week Differential revision: https://reviews.freebsd.org/D56538 --- lib/libkvm/kvm_proc.c | 8 ++++++++ sys/compat/freebsd32/freebsd32.h | 4 +++- sys/kern/kern_proc.c | 4 ++++ sys/sys/user.h | 4 +++- 4 files changed, 18 insertions(+), 2 deletions(-) diff --git a/lib/libkvm/kvm_proc.c b/lib/libkvm/kvm_proc.c index fed483978e62..a952888c9ef0 100644 --- a/lib/libkvm/kvm_proc.c +++ b/lib/libkvm/kvm_proc.c @@ -121,6 +121,7 @@ kvm_proclist(kvm_t *kd, int what, int arg, struct proc *p, struct thread mtd; struct proc proc; struct proc pproc; + struct proc rproc; struct sysentvec sysent; char svname[KI_EMULNAMELEN]; struct thread *td = NULL; @@ -365,6 +366,13 @@ nopgrp: kp->ki_xstat = KW_EXITCODE(proc.p_xexit, proc.p_xsig); kp->ki_acflag = proc.p_acflag; kp->ki_lock = proc.p_lock; + if (KREAD(kd, (u_long)proc.p_reaper, &rproc)) { + _kvm_err(kd, kd->program, + "can't read reaper at %p", proc.p_reaper); + return (-1); + } + kp->ki_reaper = rproc.p_pid; + kp->ki_reapsubtree = proc.p_reapsubtree; kp->ki_tdev_freebsd11 = kp->ki_tdev; /* truncate */ /* Per-thread items; iterate as appropriate. */ diff --git a/sys/compat/freebsd32/freebsd32.h b/sys/compat/freebsd32/freebsd32.h index 1436b630689f..3f5b93859f5c 100644 --- a/sys/compat/freebsd32/freebsd32.h +++ b/sys/compat/freebsd32/freebsd32.h @@ -392,8 +392,10 @@ struct kinfo_proc32 { char ki_emul[KI_EMULNAMELEN+1]; char ki_loginclass[LOGINCLASSLEN+1]; char ki_moretdname[MAXCOMLEN-TDNAMLEN+1]; - char ki_sparestrings[46]; + char ki_sparestrings[38]; int ki_spareints[KI_NSPARE_INT]; + pid_t ki_reaper; + pid_t ki_reapsubtree; freebsd32_uint64_t ki_tdev; int ki_oncpu; int ki_lastcpu; diff --git a/sys/kern/kern_proc.c b/sys/kern/kern_proc.c index 1f9e39a0dda3..a88ed6902f3a 100644 --- a/sys/kern/kern_proc.c +++ b/sys/kern/kern_proc.c @@ -1235,6 +1235,8 @@ fill_kinfo_proc_pgrp(struct proc *p, struct kinfo_proc *kp) kp->ki_tdev = NODEV; kp->ki_tdev_freebsd11 = kp->ki_tdev; /* truncate */ } + kp->ki_reaper = p->p_reaper->p_pid; + kp->ki_reapsubtree = p->p_reapsubtree; } /* @@ -1494,6 +1496,8 @@ freebsd32_kinfo_proc_out(const struct kinfo_proc *ki, struct kinfo_proc32 *ki32) CP(*ki, *ki32, ki_fibnum); CP(*ki, *ki32, ki_cr_flags); CP(*ki, *ki32, ki_jid); + CP(*ki, *ki32, ki_reaper); + CP(*ki, *ki32, ki_reapsubtree); CP(*ki, *ki32, ki_numthreads); CP(*ki, *ki32, ki_tid); CP(*ki, *ki32, ki_pri); diff --git a/sys/sys/user.h b/sys/sys/user.h index 59210913f889..e1a3897cd319 100644 --- a/sys/sys/user.h +++ b/sys/sys/user.h @@ -186,8 +186,10 @@ struct kinfo_proc { * front of ki_sparestrings, and ints from the end of ki_spareints. * That way the spare room from both arrays will remain contiguous. */ - char ki_sparestrings[46]; /* spare string space */ + char ki_sparestrings[38]; /* spare string space */ int ki_spareints[KI_NSPARE_INT]; /* spare room for growth */ + pid_t ki_reaper; /* pid of reaper process */ + pid_t ki_reapsubtree; /* reaper subtree id */ uint64_t ki_tdev; /* controlling tty dev */ int ki_oncpu; /* Which cpu we are on */ int ki_lastcpu; /* Last cpu we were on */home | help
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