By using the 32-bit Linux version of Sun's Java Development Kit 1.6

on FreeBSD (amd64), invocations of "javac" (or "java") eventually
end with the output of "Killed" and exit code 137.

This is caused by:
1. After calling exec() in multithreaded linux program threads are not
   destroyed and continue running. They get killed after program being
   executed finishes.

2. linux_exit_group doesn't return correct exit code when called not
   from group leader. Which happens regularly using sun jvm.

The submitters fix this in a similar way to how NetBSD handles this.

I took the PRs away from dchagin, who seems to be out of touch of
this since a while (no response from him).

The patches committed here are from [2], with some little modifications
from me to the style.

PR:		141439 [1], 144194 [2]
Submitted by:	Stefan Schmidt <stefan.schmidt@stadtbuch.de>, gk
Reviewed by:	rdivacky (in april 2010)
MFC after:	5 days

1 files changed, 38 insertions, 1 deletions

diff --git a/sys/compat/linux/linux_emul.c b/sys/compat/linux/linux_emul.c
index dc81553..eb10ca6 100644
--- a/sys/compat/linux/linux_emul.c
+++ b/sys/compat/linux/linux_emul.c
@@ -155,7 +155,7 @@ void
 linux_proc_exit(void *arg __unused, struct proc *p)
 {
 	struct linux_emuldata *em;
-	int error;
+	int error, shared_flags, shared_xstat;
 	struct thread *td = FIRST_THREAD_IN_PROC(p);
 	int *child_clear_tid;
 	struct proc *q, *nq;
@@ -187,6 +187,8 @@ linux_proc_exit(void *arg __unused, struct proc *p)
 	}
 
 	EMUL_SHARED_WLOCK(&emul_shared_lock);
+	shared_flags = em->shared->flags;
+	shared_xstat = em->shared->xstat;
 	LIST_REMOVE(em, threads);
 
 	em->shared->refs--;
@@ -196,6 +198,12 @@ linux_proc_exit(void *arg __unused, struct proc *p)
 	} else	
 		EMUL_SHARED_WUNLOCK(&emul_shared_lock);
 
+	if ((shared_flags & EMUL_SHARED_HASXSTAT) != 0) {
+		PROC_LOCK(p);
+		p->p_xstat = shared_xstat;
+		PROC_UNLOCK(p);
+	}
+
 	if (child_clear_tid != NULL) {
 		struct linux_sys_futex_args cup;
 		int null = 0;
@@ -257,6 +265,9 @@ linux_proc_exec(void *arg __unused, struct proc *p, struct image_params *imgp)
 	if (__predict_false(imgp->sysent == &elf_linux_sysvec
 	    && p->p_sysent != &elf_linux_sysvec))
 		linux_proc_init(FIRST_THREAD_IN_PROC(p), p->p_pid, 0);
+	if (__predict_false(p->p_sysent == &elf_linux_sysvec))
+		/* Kill threads regardless of imgp->sysent value */
+		linux_kill_threads(FIRST_THREAD_IN_PROC(p), SIGKILL);
 	if (__predict_false(imgp->sysent != &elf_linux_sysvec
 	    && p->p_sysent == &elf_linux_sysvec)) {
 		struct linux_emuldata *em;
@@ -334,3 +345,29 @@ linux_set_tid_address(struct thread *td, struct linux_set_tid_address_args *args
 	EMUL_UNLOCK(&emul_lock);
 	return 0;
 }
+
+void
+linux_kill_threads(struct thread *td, int sig)
+{
+	struct linux_emuldata *em, *td_em, *tmp_em;
+	struct proc *sp;
+
+	td_em = em_find(td->td_proc, EMUL_DONTLOCK);
+
+	KASSERT(td_em != NULL, ("linux_kill_threads: emuldata not found.\n"));
+
+	EMUL_SHARED_RLOCK(&emul_shared_lock);
+	LIST_FOREACH_SAFE(em, &td_em->shared->threads, threads, tmp_em) {
+		if (em->pid == td_em->pid)
+			continue;
+
+		sp = pfind(em->pid);
+		if ((sp->p_flag & P_WEXIT) == 0)
+			psignal(sp, sig);
+		PROC_UNLOCK(sp);
+#ifdef DEBUG
+		printf(LMSG("linux_kill_threads: kill PID %d\n"), em->pid);
+#endif
+	}
+	EMUL_SHARED_RUNLOCK(&emul_shared_lock);
+}