Deprecate find_task_by_pid()

There are some places that are known to operate on tasks'
global pids only:

* the rest_init() call (called on boot)
* the kgdb's getthread
* the create_kthread() (since the kthread is run in init ns)

So use the find_task_by_pid_ns(..., &init_pid_ns) there
and schedule the find_task_by_pid for removal.

[sukadev@us.ibm.com: Fix warning in kernel/pid.c]
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Sukadev Bhattiprolu <sukadev@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 18 insertions, 0 deletions

diff --git a/Documentation/feature-removal-schedule.txt b/Documentation/feature-removal-schedule.txt
index 599fe55bf297..3c35d452b1a9 100644
--- a/Documentation/feature-removal-schedule.txt
+++ b/Documentation/feature-removal-schedule.txt
@@ -138,6 +138,24 @@ Who:	Kay Sievers <kay.sievers@suse.de>
 
 ---------------------------
 
+What:   find_task_by_pid
+When:   2.6.26
+Why:    With pid namespaces, calling this funciton will return the
+        wrong task when called from inside a namespace.
+
+        The best way to save a task pid and find a task by this
+        pid later, is to find this task's struct pid pointer (or get
+        it directly from the task) and call pid_task() later.
+
+        If someone really needs to get a task by its pid_t, then
+        he most likely needs the find_task_by_vpid() to get the
+        task from the same namespace as the current task is in, but
+        this may be not so in general.
+
+Who:    Pavel Emelyanov <xemul@openvz.org>
+
+---------------------------
+
 What:   ACPI procfs interface
 When:   July 2008
 Why:    ACPI sysfs conversion should be finished by January 2008.