(Forced commit, to clarify previous commit of ksiginfo/signal queue code.)

I've added a structure, kernel-private, to represent a pending or in-delivery
signal, called `ksiginfo'.  It is roughly analogous to the basic information
that is exported by the POSIX interface 'siginfo_t', but more basic.  I've
added functions to allocate these structures, and further to wrap all signal
operations using them.

Once the operations are wrapped, I've added a TailQ (see queue(3)) of these
structures to 'struct proc', and all pending signals are in that TailQ.  When
a signal is being delivered, it is dequeued from the list.  Once I finish
the spreading of ksiginfo throughout the tree, the dequeued structure will be
delivered to the process in question, whereas currently and normally, the
signal number is what is used.

3 files changed, 28 insertions, 4 deletions

diff --git a/sys/kern/kern_sig.c b/sys/kern/kern_sig.c
index ada2016..5e42a7e 100644
--- a/sys/kern/kern_sig.c
+++ b/sys/kern/kern_sig.c
@@ -1227,8 +1227,11 @@ trapsignal(p, sig, code)
 	u_long code;
 {
 	register struct sigacts *ps = p->p_sigacts;
+	struct ksiginfo *ksi;
 
 	PROC_LOCK(p);
+	ksiginfo_alloc(&ksi, sig);
+	ksi->ksi_code = code;
 	if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(p->p_sigcatch, sig) &&
 	    !SIGISMEMBER(p->p_sigmask, sig)) {
 		p->p_stats->p_ru.ru_nsignals++;
@@ -1237,8 +1240,8 @@ trapsignal(p, sig, code)
 			ktrpsig(sig, ps->ps_sigact[_SIG_IDX(sig)],
 			    &p->p_sigmask, code);
 #endif
-		(*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], sig,
-						&p->p_sigmask, code);
+		(*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], ksi,
+						&p->p_sigmask);
 		SIGSETOR(p->p_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]);
 		if (!SIGISMEMBER(ps->ps_signodefer, sig))
 			SIGADDSET(p->p_sigmask, sig);
@@ -1799,6 +1802,7 @@ postsig(sig)
 {
 	struct thread *td = curthread;
 	register struct proc *p = td->td_proc;
+	struct ksiginfo *ksi;
 	struct sigacts *ps;
 	sig_t action;
 	sigset_t returnmask;
@@ -1808,7 +1812,7 @@ postsig(sig)
 
 	PROC_LOCK_ASSERT(p, MA_OWNED);
 	ps = p->p_sigacts;
-	signal_delete(p, NULL, sig);
+	ksiginfo_dequeue(&ksi, p, sig);
 	action = ps->ps_sigact[_SIG_IDX(sig)];
 #ifdef KTRACE
 	if (KTRPOINT(td, KTR_PSIG))
@@ -1822,6 +1826,7 @@ postsig(sig)
 		 * Default action, where the default is to kill
 		 * the process.  (Other cases were ignored above.)
 		 */
+		ksiginfo_destroy(&ksi);
 		sigexit(td, sig);
 		/* NOTREACHED */
 	} else {
@@ -1870,7 +1875,7 @@ postsig(sig)
 		if (p->p_flag & P_KSES)
 			if (signal_upcall(p, sig))
 				return;
-		(*p->p_sysent->sv_sendsig)(action, sig, &returnmask, code);
+		(*p->p_sysent->sv_sendsig)(action, ksi, &returnmask);
 	}
 }
 
diff --git a/sys/kern/subr_sigq.c b/sys/kern/subr_sigq.c
index fa44fab..cf5dd50 100644
--- a/sys/kern/subr_sigq.c
+++ b/sys/kern/subr_sigq.c
@@ -118,6 +118,23 @@ out:
 }
 
 int
+ksiginfo_to_siginfo_t(struct ksiginfo *ksi, siginfo_t *si)
+{
+	int error;
+
+	error = 0;
+
+	si->si_addr = ksi->ksi_addr;
+	si->si_code = ksi->ksi_code;
+	si->si_errno = ksi->ksi_errno;
+	si->si_signo = ksi->ksi_errno;
+	si->si_status = ksi->ksi_status;
+	si->si_uid = ksi->ksi_ruid;
+	si->si_pid = ksi->ksi_pid;
+	return (error);
+}
+
+int
 ksiginfo_to_sigset_t(struct proc *p, sigset_t *setp)
 {
 	int error;
diff --git a/sys/sys/ksiginfo.h b/sys/sys/ksiginfo.h
index 26b88d5..40d9542 100644
--- a/sys/sys/ksiginfo.h
+++ b/sys/sys/ksiginfo.h
@@ -36,6 +36,7 @@
 #endif
 
 #include <sys/malloc.h>
+#include <sys/signal.h>
 
 /*
  * Structures and prototypes for working with the in-kernel representation
@@ -66,6 +67,7 @@ __BEGIN_DECLS;
 int ksiginfo_alloc(struct ksiginfo **, int);
 int ksiginfo_dequeue(struct ksiginfo **, struct proc *, int);
 int ksiginfo_destroy(struct ksiginfo **);
+int ksiginfo_to_siginfo_t(struct ksiginfo *, siginfo_t *);
 int ksiginfo_to_sigset_t(struct proc *, sigset_t *);
 int signal_add(struct proc *, struct ksiginfo *, int);
 int signal_delete(struct proc *, struct ksiginfo *, int);