Add the wait6(2) system call. It takes POSIX waitid()-like process

designator to select a process which is waited for. The system call
optionally returns siginfo_t which would be otherwise provided to
SIGCHLD handler, as well as extended structure accounting for child
and cumulative grandchild resource usage.

Allow to get the current rusage information for non-exited processes
as well, similar to Solaris.

The explicit WEXITED flag is required to wait for exited processes,
allowing for more fine-grained control of the events the waiter is
interested in.

Fix the handling of siginfo for WNOWAIT option for all wait*(2)
family, by not removing the queued signal state.

PR:	standards/170346
Submitted by:	"Jukka A. Ukkonen" <jau@iki.fi>
MFC after:	1 month

3 files changed, 48 insertions, 0 deletions

diff --git a/sys/compat/freebsd32/freebsd32.h b/sys/compat/freebsd32/freebsd32.h
index fccdef0..a95b0e5 100644
--- a/sys/compat/freebsd32/freebsd32.h
+++ b/sys/compat/freebsd32/freebsd32.h
@@ -88,6 +88,11 @@ struct rusage32 {
 	int32_t	ru_nivcsw;
 };
 
+struct wrusage32 {
+	struct rusage32	wru_self;
+	struct rusage32 wru_children;
+};
+
 struct itimerval32 {
 	struct timeval32 it_interval;
 	struct timeval32 it_value;
diff --git a/sys/compat/freebsd32/freebsd32_misc.c b/sys/compat/freebsd32/freebsd32_misc.c
index ce8bd7a..8c5f5a6 100644
--- a/sys/compat/freebsd32/freebsd32_misc.c
+++ b/sys/compat/freebsd32/freebsd32_misc.c
@@ -180,6 +180,44 @@ freebsd32_wait4(struct thread *td, struct freebsd32_wait4_args *uap)
 	return (error);
 }
 
+int
+freebsd32_wait6(struct thread *td, struct freebsd32_wait6_args *uap)
+{
+	struct wrusage32 wru32;
+	struct __wrusage wru, *wrup;
+	struct siginfo32 si32;
+	struct __siginfo si, *sip;
+	int error, status;
+
+	if (uap->wrusage != NULL)
+		wrup = &wru;
+	else
+		wrup = NULL;
+
+	if (uap->info != NULL) {
+		sip = &si;
+		bzero(sip, sizeof(*sip));
+	} else
+		sip = NULL;
+
+	error = kern_wait6(td, uap->idtype, uap->id, &status, uap->options,
+	    wrup, sip);
+	if (error != 0)
+		return (error);
+	if (uap->status != NULL)
+		error = copyout(&status, uap->status, sizeof(status));
+	if (uap->wrusage != NULL && error == 0) {
+		freebsd32_rusage_out(&wru.wru_self, &wru32.wru_self);
+		freebsd32_rusage_out(&wru.wru_children, &wru32.wru_children);
+		error = copyout(&wru32, uap->wrusage, sizeof(wru32));
+	}
+	if (uap->info != NULL && error == 0) {
+		siginfo_to_siginfo32 (&si, &si32);
+		error = copyout(&si32, uap->info, sizeof(si32));
+	}
+	return (error);
+}
+
 #ifdef COMPAT_FREEBSD4
 static void
 copy_statfs(struct statfs *in, struct statfs32 *out)
diff --git a/sys/compat/freebsd32/syscalls.master b/sys/compat/freebsd32/syscalls.master
index 478558a..4106447 100644
--- a/sys/compat/freebsd32/syscalls.master
+++ b/sys/compat/freebsd32/syscalls.master
@@ -1000,3 +1000,8 @@
 				    uint32_t offset1, uint32_t offset2,\
 				    uint32_t len1, uint32_t len2, \
 				    int advice); }
+532	AUE_WAIT6	STD	{ int freebsd32_wait6(int idtype, int id, \
+				    int *status, int options, \
+				    struct wrusage32 *wrusage, \
+				    siginfo_t *info); }
+