diff --git a/sys/fs/nfs/nfs_commonkrpc.c b/sys/fs/nfs/nfs_commonkrpc.c
index 23d89547ff06..f08ba854ea69 100644
--- a/sys/fs/nfs/nfs_commonkrpc.c
+++ b/sys/fs/nfs/nfs_commonkrpc.c
@@ -1031,7 +1031,6 @@ int newnfs_sig_set[] = {
SIGTERM,
SIGHUP,
SIGKILL,
- SIGSTOP,
SIGQUIT
};
@@ -1052,7 +1051,7 @@ nfs_sig_pending(sigset_t set)
/*
* The set/restore sigmask functions are used to (temporarily) overwrite
- * the process p_sigmask during an RPC call (for example). These are also
+ * the thread td_sigmask during an RPC call (for example). These are also
* used in other places in the NFS client that might tsleep().
*/
void
@@ -1081,8 +1080,10 @@ newnfs_set_sigmask(struct thread *td, sigset_t *oldset)
SIGDELSET(newset, newnfs_sig_set[i]);
}
mtx_unlock(&p->p_sigacts->ps_mtx);
+ sigdeferstop(td);
+ kern_sigprocmask(td, SIG_SETMASK, &newset, oldset,
+ SIGPROCMASK_PROC_LOCKED);
PROC_UNLOCK(p);
- kern_sigprocmask(td, SIG_SETMASK, &newset, oldset, 0);
}
void
@@ -1091,6 +1092,7 @@ newnfs_restore_sigmask(struct thread *td, sigset_t *set)
if (td == NULL)
td = curthread; /* XXX */
kern_sigprocmask(td, SIG_SETMASK, set, NULL, 0);
+ sigallowstop(td);
}
/*
diff --git a/sys/kern/kern_sig.c b/sys/kern/kern_sig.c
index 9c5270726ead..e28bdc41ce1b 100644
--- a/sys/kern/kern_sig.c
+++ b/sys/kern/kern_sig.c
@@ -2363,6 +2363,13 @@ tdsigwakeup(struct thread *td, int sig, sig_t action, int intrval)
return;
}
+ /*
+ * Don't awaken a sleeping thread for SIGSTOP if the
+ * STOP signal is deferred.
+ */
+ if ((prop & SA_STOP) && (td->td_flags & TDF_SBDRY))
+ goto out;
+
/*
* Give low priority threads a better chance to run.
*/
@@ -2404,12 +2411,13 @@ sig_suspend_threads(struct thread *td, struct proc *p, int sending)
if ((TD_IS_SLEEPING(td2) || TD_IS_SWAPPED(td2)) &&
(td2->td_flags & TDF_SINTR)) {
if (td2->td_flags & TDF_SBDRY) {
- if (TD_IS_SUSPENDED(td2))
- wakeup_swapper |=
- thread_unsuspend_one(td2);
- if (TD_ON_SLEEPQ(td2))
- wakeup_swapper |=
- sleepq_abort(td2, ERESTART);
+ /*
+ * Once a thread is asleep with
+ * TDF_SBDRY set, it should never
+ * become suspended due to this check.
+ */
+ KASSERT(!TD_IS_SUSPENDED(td2),
+ ("thread with deferred stops suspended"));
} else if (!TD_IS_SUSPENDED(td2)) {
thread_suspend_one(td2);
}
@@ -2529,6 +2537,34 @@ tdsigcleanup(struct thread *td)
}
+/* Defer the delivery of SIGSTOP for the current thread. */
+void
+sigdeferstop(struct thread *td)
+{
+
+ KASSERT(!(td->td_flags & TDF_SBDRY),
+ ("attempt to set TDF_SBDRY recursively"));
+ thread_lock(td);
+ td->td_flags |= TDF_SBDRY;
+ thread_unlock(td);
+}
+
+/*
+ * Permit the delivery of SIGSTOP for the current thread. This does
+ * not immediately suspend if a stop was posted. Instead, the thread
+ * will suspend either via ast() or a subsequent interruptible sleep.
+ */
+void
+sigallowstop(struct thread *td)
+{
+
+ KASSERT(td->td_flags & TDF_SBDRY,
+ ("attempt to clear already-cleared TDF_SBDRY"));
+ thread_lock(td);
+ td->td_flags &= ~TDF_SBDRY;
+ thread_unlock(td);
+}
+
/*
* If the current process has received a signal (should be caught or cause
* termination, should interrupt current syscall), return the signal number.
@@ -2561,7 +2597,7 @@ issignal(struct thread *td, int stop_allowed)
SIGSETOR(sigpending, p->p_sigqueue.sq_signals);
SIGSETNAND(sigpending, td->td_sigmask);
- if (p->p_flag & P_PPWAIT)
+ if (p->p_flag & P_PPWAIT || td->td_flags & TDF_SBDRY)
SIG_STOPSIGMASK(sigpending);
if (SIGISEMPTY(sigpending)) /* no signal to send */
return (0);
@@ -2677,10 +2713,6 @@ issignal(struct thread *td, int stop_allowed)
(p->p_pgrp->pg_jobc == 0 &&
prop & SA_TTYSTOP))
break; /* == ignore */
-
- /* Ignore, but do not drop the stop signal. */
- if (stop_allowed != SIG_STOP_ALLOWED)
- return (sig);
mtx_unlock(&ps->ps_mtx);
WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK,
&p->p_mtx.lock_object, "Catching SIGSTOP");
diff --git a/sys/kern/subr_sleepqueue.c b/sys/kern/subr_sleepqueue.c
index 2d5ea511aafd..b6bd8fcc8842 100644
--- a/sys/kern/subr_sleepqueue.c
+++ b/sys/kern/subr_sleepqueue.c
@@ -352,8 +352,6 @@ sleepq_add(void *wchan, struct lock_object *lock, const char *wmesg, int flags,
if (flags & SLEEPQ_INTERRUPTIBLE) {
td->td_flags |= TDF_SINTR;
td->td_flags &= ~TDF_SLEEPABORT;
- if (flags & SLEEPQ_STOP_ON_BDRY)
- td->td_flags |= TDF_SBDRY;
}
thread_unlock(td);
}
@@ -600,7 +598,7 @@ sleepq_check_signals(void)
/* We are no longer in an interruptible sleep. */
if (td->td_flags & TDF_SINTR)
- td->td_flags &= ~(TDF_SINTR | TDF_SBDRY);
+ td->td_flags &= ~TDF_SINTR;
if (td->td_flags & TDF_SLEEPABORT) {
td->td_flags &= ~TDF_SLEEPABORT;
@@ -747,7 +745,7 @@ sleepq_resume_thread(struct sleepqueue *sq, struct thread *td, int pri)
td->td_wmesg = NULL;
td->td_wchan = NULL;
- td->td_flags &= ~(TDF_SINTR | TDF_SBDRY);
+ td->td_flags &= ~TDF_SINTR;
CTR3(KTR_PROC, "sleepq_wakeup: thread %p (pid %ld, %s)",
(void *)td, (long)td->td_proc->p_pid, td->td_name);
diff --git a/sys/nfsclient/nfs_krpc.c b/sys/nfsclient/nfs_krpc.c
index dd441ae29de3..851b0b618389 100644
--- a/sys/nfsclient/nfs_krpc.c
+++ b/sys/nfsclient/nfs_krpc.c
@@ -699,7 +699,6 @@ int nfs_sig_set[] = {
SIGTERM,
SIGHUP,
SIGKILL,
- SIGSTOP,
SIGQUIT
};
@@ -720,7 +719,7 @@ nfs_sig_pending(sigset_t set)
/*
* The set/restore sigmask functions are used to (temporarily) overwrite
- * the process p_sigmask during an RPC call (for example). These are also
+ * the thread td_sigmask during an RPC call (for example). These are also
* used in other places in the NFS client that might tsleep().
*/
void
@@ -749,8 +748,10 @@ nfs_set_sigmask(struct thread *td, sigset_t *oldset)
SIGDELSET(newset, nfs_sig_set[i]);
}
mtx_unlock(&p->p_sigacts->ps_mtx);
+ sigdeferstop(td);
+ kern_sigprocmask(td, SIG_SETMASK, &newset, oldset,
+ SIGPROCMASK_PROC_LOCKED);
PROC_UNLOCK(p);
- kern_sigprocmask(td, SIG_SETMASK, &newset, oldset, 0);
}
void
@@ -759,6 +760,7 @@ nfs_restore_sigmask(struct thread *td, sigset_t *set)
if (td == NULL)
td = curthread; /* XXX */
kern_sigprocmask(td, SIG_SETMASK, set, NULL, 0);
+ sigallowstop(td);
}
/*
diff --git a/sys/sys/signalvar.h b/sys/sys/signalvar.h
index 71685e7e5bd7..91655b25a5d0 100644
--- a/sys/sys/signalvar.h
+++ b/sys/sys/signalvar.h
@@ -328,6 +328,8 @@ extern struct mtx sigio_lock;
#define SIGPROCMASK_PS_LOCKED 0x0004
int cursig(struct thread *td, int stop_allowed);
+void sigdeferstop(struct thread *td);
+void sigallowstop(struct thread *td);
void execsigs(struct proc *p);
void gsignal(int pgid, int sig, ksiginfo_t *ksi);
void killproc(struct proc *p, char *why);