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authorSukadev Bhattiprolu <sukadev@us.ibm.com>2006-09-29 02:00:07 -0700
committerLinus Torvalds <torvalds@g5.osdl.org>2006-09-29 09:18:12 -0700
commitf400e198b2ed26ce55b22a1412ded0896e7516ac (patch)
treea3d78bfc1c20635e199fe0fe85aaa1d8792acc58 /include
parent959ed340f4867fda7684340625f60e211c2296d6 (diff)
[PATCH] pidspace: is_init()
This is an updated version of Eric Biederman's is_init() patch. (http://lkml.org/lkml/2006/2/6/280). It applies cleanly to 2.6.18-rc3 and replaces a few more instances of ->pid == 1 with is_init(). Further, is_init() checks pid and thus removes dependency on Eric's other patches for now. Eric's original description: There are a lot of places in the kernel where we test for init because we give it special properties. Most significantly init must not die. This results in code all over the kernel test ->pid == 1. Introduce is_init to capture this case. With multiple pid spaces for all of the cases affected we are looking for only the first process on the system, not some other process that has pid == 1. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Sukadev Bhattiprolu <sukadev@us.ibm.com> Cc: Dave Hansen <haveblue@us.ibm.com> Cc: Serge Hallyn <serue@us.ibm.com> Cc: Cedric Le Goater <clg@fr.ibm.com> Cc: <lxc-devel@lists.sourceforge.net> Acked-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'include')
-rw-r--r--include/linux/sched.h10
1 files changed, 10 insertions, 0 deletions
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 3696f2f7126..ed2af867158 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1033,6 +1033,16 @@ static inline int pid_alive(struct task_struct *p)
return p->pids[PIDTYPE_PID].pid != NULL;
}
+/**
+ * is_init - check if a task structure is the first user space
+ * task the kernel created.
+ * @p: Task structure to be checked.
+ */
+static inline int is_init(struct task_struct *tsk)
+{
+ return tsk->pid == 1;
+}
+
extern void free_task(struct task_struct *tsk);
#define get_task_struct(tsk) do { atomic_inc(&(tsk)->usage); } while(0)