Subject: [PATCH] Generalize killing all processes to work in process groups, and to work
From: Eric W. Biederman <ebiederman@lnxi.com>
Date: 1129507113 -0600

externall from the process group.

---

 kernel/signal.c |   71 ++++++++++++++++++++++++++++++++++++++++++++-----------
 1 files changed, 57 insertions(+), 14 deletions(-)

46d02452455338e61ece83d77172cfc8a0ac16a6
diff --git a/kernel/signal.c b/kernel/signal.c
index 5b89b8f..8228f81 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -1145,6 +1145,51 @@ int group_send_sig_info(int sig, struct 
 }
 
 /*
+ * kill_pspace_info() sends a signal to all processes in a process id space.
+ * This is what kill(-1, sig) does.
+ */
+
+int __kill_pspace_info(int sig, struct siginfo *info, pid_t pspaceid)
+{
+	struct task_struct *p = NULL;
+	struct pspace *pspace;
+	pid_t min, max;
+	int retval = 0, count = 0;
+
+	p = find_task_by_pid_type(PIDTYPE_TGID, pspaceid);
+	if (!p || (p->tgid != (p->pspace->offset + 1)))
+		return -ESRCH;
+
+	pspace = p->pspace;
+	min = pspace->offset; 
+	max = pspace->offset + pspace->max;
+
+	for_each_process(p) {
+		if ((p->pid != current->pspace->offset + 1) && (p->tgid != current->tgid) &&
+			(p->pid > min) && (p->pid < max))
+		{
+			int err = group_send_sig_info(sig, info, p);
+			++count;
+			if (err != -EPERM)
+				retval = err;
+		}
+	}
+	return count ? retval : -ESRCH;
+}
+
+int
+kill_pspace_info(int sig, struct siginfo *info, pid_t pspaceid)
+{
+	int retval;
+
+	read_lock(&tasklist_lock);
+	retval = __kill_pspace_info(sig, info, pspaceid);
+	read_unlock(&tasklist_lock);
+
+	return retval;
+}
+
+/*
  * kill_pg_info() sends a signal to a process group: this is what the tty
  * control characters do (^C, ^Z etc)
  */
@@ -1200,29 +1245,27 @@ kill_proc_info(int sig, struct siginfo *
  *
  * POSIX specifies that kill(-1,sig) is unspecified, but what we have
  * is probably wrong.  Should make it like BSD or SYSV.
+ *
+ * This has been extended to treak all process spaces just like kill(-1, sig)
  */
 
 static int kill_something_info(int sig, struct siginfo *info, int pid)
 {
 	if (!pid) {
 		return kill_pg_info(sig, info, process_group(current));
-	} else if (pid == -1) {
-		int retval = 0, count = 0;
-		struct task_struct * p;
+	} else if (pid < 0) {
+		struct task_struct *p;
+		int retval;
 
+		pid = pid_from_user(-pid);
 		read_lock(&tasklist_lock);
-		for_each_process(p) {
-			if (p->pid > 1 && p->tgid != current->tgid && pid_visible(p)) {
-				int err = group_send_sig_info(sig, info, p);
-				++count;
-				if (err != -EPERM)
-					retval = err;
-			}
-		}
+		p = find_task_by_pid_type(PIDTYPE_TGID, pid);
+		if (likely(!p || (p->tgid != (p->pspace->offset + 1))))
+			retval = __kill_pg_info(sig, info, pid);
+		else
+			retval = __kill_pspace_info(sig, info, pid);
 		read_unlock(&tasklist_lock);
-		return count ? retval : -ESRCH;
-	} else if (pid < 0) {
-		return kill_pg_info(sig, info, pid_from_user(-pid));
+		return retval;
 	} else {
 		return kill_proc_info(sig, info, pid_from_user(pid));
 	}
-- 
1.0.GIT