From f0794b6f83c2aaadf072e1c63dfd9a45d7503f6b Mon Sep 17 00:00:00 2001 From: mpi Date: Mon, 8 Mar 2021 10:12:05 +0000 Subject: [PATCH] Kill SINGLE_PTRACE and use SINGLE_SUSPEND which has almost the same semantic. single_thread_set() is modified to explicitly indicated when waiting until sibling threads are parked is required. This is obviously not required if a traced thread is switching away from a CPU after handling a STOP signal. ok claudio@ --- sys/kern/kern_exec.c | 4 ++-- sys/kern/kern_exit.c | 4 ++-- sys/kern/kern_sig.c | 16 ++++++---------- 3 files changed, 10 insertions(+), 14 deletions(-) diff --git a/sys/kern/kern_exec.c b/sys/kern/kern_exec.c index 8f5e05aac67..192d5e66ff6 100644 --- a/sys/kern/kern_exec.c +++ b/sys/kern/kern_exec.c @@ -1,4 +1,4 @@ -/* $OpenBSD: kern_exec.c,v 1.219 2020/10/15 16:31:11 cheloha Exp $ */ +/* $OpenBSD: kern_exec.c,v 1.220 2021/03/08 10:12:05 mpi Exp $ */ /* $NetBSD: kern_exec.c,v 1.75 1996/02/09 18:59:28 christos Exp $ */ /*- @@ -432,7 +432,7 @@ sys_execve(struct proc *p, void *v, register_t *retval) * we're committed: any further errors will kill the process, so * kill the other threads now. */ - single_thread_set(p, SINGLE_EXIT, 0); + single_thread_set(p, SINGLE_EXIT, 1); /* * Prepare vmspace for remapping. Note that uvmspace_exec can replace diff --git a/sys/kern/kern_exit.c b/sys/kern/kern_exit.c index cbb116e6dcc..fa72891271e 100644 --- a/sys/kern/kern_exit.c +++ b/sys/kern/kern_exit.c @@ -1,4 +1,4 @@ -/* $OpenBSD: kern_exit.c,v 1.196 2021/02/15 09:35:59 mpi Exp $ */ +/* $OpenBSD: kern_exit.c,v 1.197 2021/03/08 10:12:05 mpi Exp $ */ /* $NetBSD: kern_exit.c,v 1.39 1996/04/22 01:38:25 christos Exp $ */ /* @@ -136,7 +136,7 @@ exit1(struct proc *p, int xexit, int xsig, int flags) } else { /* nope, multi-threaded */ if (flags == EXIT_NORMAL) - single_thread_set(p, SINGLE_EXIT, 0); + single_thread_set(p, SINGLE_EXIT, 1); else if (flags == EXIT_THREAD) single_thread_check(p, 0); } diff --git a/sys/kern/kern_sig.c b/sys/kern/kern_sig.c index 8f957beab20..d4f87e7c68f 100644 --- a/sys/kern/kern_sig.c +++ b/sys/kern/kern_sig.c @@ -1,4 +1,4 @@ -/* $OpenBSD: kern_sig.c,v 1.274 2021/03/04 09:02:37 mpi Exp $ */ +/* $OpenBSD: kern_sig.c,v 1.275 2021/03/08 10:12:05 mpi Exp $ */ /* $NetBSD: kern_sig.c,v 1.54 1996/04/22 01:38:32 christos Exp $ */ /* @@ -1490,7 +1490,7 @@ sigexit(struct proc *p, int signum) /* if there are other threads, pause them */ if (P_HASSIBLING(p)) - single_thread_set(p, SINGLE_SUSPEND, 0); + single_thread_set(p, SINGLE_SUSPEND, 1); if (coredump(p) == 0) signum |= WCOREFLAG; @@ -2000,14 +2000,12 @@ single_thread_check(struct proc *p, int deep) * where the other threads should stop: * - SINGLE_SUSPEND: stop wherever they are, will later either be told to exit * (by setting to SINGLE_EXIT) or be released (via single_thread_clear()) - * - SINGLE_PTRACE: stop wherever they are, will wait for them to stop - * later (via single_thread_wait()) and released as with SINGLE_SUSPEND * - SINGLE_UNWIND: just unwind to kernel boundary, will be told to exit * or released as with SINGLE_SUSPEND * - SINGLE_EXIT: unwind to kernel boundary and exit */ int -single_thread_set(struct proc *p, enum single_thread_mode mode, int deep) +single_thread_set(struct proc *p, enum single_thread_mode mode, int wait) { struct process *pr = p->p_p; struct proc *q; @@ -2016,7 +2014,7 @@ single_thread_set(struct proc *p, enum single_thread_mode mode, int deep) KASSERT(curproc == p); SCHED_LOCK(s); - error = single_thread_check_locked(p, deep, s); + error = single_thread_check_locked(p, (mode == SINGLE_UNWIND), s); if (error) { SCHED_UNLOCK(s); return error; @@ -2024,7 +2022,6 @@ single_thread_set(struct proc *p, enum single_thread_mode mode, int deep) switch (mode) { case SINGLE_SUSPEND: - case SINGLE_PTRACE: break; case SINGLE_UNWIND: atomic_setbits_int(&pr->ps_flags, PS_SINGLEUNWIND); @@ -2063,8 +2060,7 @@ single_thread_set(struct proc *p, enum single_thread_mode mode, int deep) /* if it's not interruptible, then just have to wait */ if (q->p_flag & P_SINTR) { /* merely need to suspend? just stop it */ - if (mode == SINGLE_SUSPEND || - mode == SINGLE_PTRACE) { + if (mode == SINGLE_SUSPEND) { q->p_stat = SSTOP; break; } @@ -2089,7 +2085,7 @@ single_thread_set(struct proc *p, enum single_thread_mode mode, int deep) } SCHED_UNLOCK(s); - if (mode != SINGLE_PTRACE) + if (wait) single_thread_wait(pr, 1); return 0; -- 2.20.1