Subject: [PATCH] Modify pid_visible to take a pid argument and not a task argument
From: Eric W. Biederman <ebiederman@lnxi.com>
Date: 1129748713 -0600

---

 fs/proc/array.c        |    6 +++---
 fs/proc/base.c         |    4 ++--
 include/linux/pspace.h |    4 ++--
 kernel/timer.c         |    2 +-
 4 files changed, 8 insertions(+), 8 deletions(-)

823513a802c9b991c117baaa07b8784a6e0a607e
diff --git a/fs/proc/array.c b/fs/proc/array.c
index 59abcf7..4721c5d 100644
--- a/fs/proc/array.c
+++ b/fs/proc/array.c
@@ -167,9 +167,9 @@ static inline char * task_state(struct t
 	read_lock(&tasklist_lock);
 	tgid  = pid_to_user(p->tgid);
 	pid   = pid_to_user(p->pid);
-	ptgid = pid_alive(p) && pid_visible(p->group_leader->real_parent) ? 
+	ptgid = pid_alive(p) && pid_visible(p->group_leader->real_parent->tgid) ? 
 		pid_to_user(p->group_leader->real_parent->tgid) : 0;
-	tppid = pid_alive(p) && pid_visible(p->parent) && p->ptrace ? 
+	tppid = pid_alive(p) && pid_visible(p->parent->pid) && p->ptrace ? 
 		pid_to_user(p->parent->pid) : 0;
 	buffer += sprintf(buffer,
 		"State:\t%s\n"
@@ -394,7 +394,7 @@ static int do_task_stat(struct task_stru
 		}
 		it_real_value = task->signal->it_real_value;
 	}
-	ppid = pid_alive(task) && pid_visible(task->group_leader->real_parent) ? 
+	ppid = pid_alive(task) && pid_visible(task->group_leader->real_parent->tgid) ? 
 		pid_to_user(task->group_leader->real_parent->tgid) : 0;
 	read_unlock(&tasklist_lock);
 
diff --git a/fs/proc/base.c b/fs/proc/base.c
index d4ccf34..fb5fef8 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -2062,7 +2062,7 @@ static int get_tgid_list(int index, unsi
 		int tgid = p->pid;
 		if (!pid_alive(p))
 			continue;
-		if (!pid_visible(p))
+		if (!pid_visible(p->tgid))
 			continue;
 		if (--index >= 0)
 			continue;
@@ -2093,7 +2093,7 @@ static int get_tid_list(int index, unsig
 	 * unlinked task, which cannot be used to access the task-list
 	 * via next_thread().
 	 */
-	if (pid_alive(task) && pid_visible(task)) do {
+	if (pid_alive(task) && pid_visible(task->pid)) do {
 		int tid = task->pid;
 
 		if (--index >= 0)
diff --git a/include/linux/pspace.h b/include/linux/pspace.h
index 4506670..ab0ed58 100644
--- a/include/linux/pspace.h
+++ b/include/linux/pspace.h
@@ -44,9 +44,9 @@ static inline int pid_to_user(int pid)
 	return pid - current->pspace->offset;
 }
 
-static inline int pid_visible(struct task_struct *p)
+static inline int pid_visible(int pid)
 {
-	int pid = pid_to_user(p->pid);
+	pid = pid_to_user(pid);
 	return (pid > 0) && (pid < current->pspace->max);
 }
 
diff --git a/kernel/timer.c b/kernel/timer.c
index cdd6080..b7a65e3 100644
--- a/kernel/timer.c
+++ b/kernel/timer.c
@@ -1024,7 +1024,7 @@ asmlinkage long sys_getppid(void)
 
 	parent = me->group_leader->real_parent;
 	for (;;) {
-		pid = pid_visible(parent)? pid_to_user(parent->tgid) : 0;
+		pid = pid_visible(parent->tgid)? pid_to_user(parent->tgid) : 0;
 #if defined(CONFIG_SMP) || defined(CONFIG_PREEMPT)
 {
 		struct task_struct *old = parent;
-- 
1.0.GIT