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| author | Serge E. Hallyn <serue@us.ibm.com> | 2007-10-19 10:39:52 +0400 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-10-19 22:53:37 +0400 |
| commit | b460cbc581a53cc088ceba80608021dd49c63c43 (patch) | |
| tree | 83c28d0adbc15f4157c77b40fa60c40a71cb8673 /kernel/pid.c | |
| parent | 3743ca05ff464b8a9e345c08a6c9ce30485f9805 (diff) | |
| download | linux-b460cbc581a53cc088ceba80608021dd49c63c43.tar.xz | |
pid namespaces: define is_global_init() and is_container_init()
is_init() is an ambiguous name for the pid==1 check. Split it into
is_global_init() and is_container_init().
A cgroup init has it's tsk->pid == 1.
A global init also has it's tsk->pid == 1 and it's active pid namespace
is the init_pid_ns. But rather than check the active pid namespace,
compare the task structure with 'init_pid_ns.child_reaper', which is
initialized during boot to the /sbin/init process and never changes.
Changelog:
2.6.22-rc4-mm2-pidns1:
- Use 'init_pid_ns.child_reaper' to determine if a given task is the
global init (/sbin/init) process. This would improve performance
and remove dependence on the task_pid().
2.6.21-mm2-pidns2:
- [Sukadev Bhattiprolu] Changed is_container_init() calls in {powerpc,
ppc,avr32}/traps.c for the _exception() call to is_global_init().
This way, we kill only the cgroup if the cgroup's init has a
bug rather than force a kernel panic.
[akpm@linux-foundation.org: fix comment]
[sukadev@us.ibm.com: Use is_global_init() in arch/m32r/mm/fault.c]
[bunk@stusta.de: kernel/pid.c: remove unused exports]
[sukadev@us.ibm.com: Fix capability.c to work with threaded init]
Signed-off-by: Serge E. Hallyn <serue@us.ibm.com>
Signed-off-by: Sukadev Bhattiprolu <sukadev@us.ibm.com>
Acked-by: Pavel Emelianov <xemul@openvz.org>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Cedric Le Goater <clg@fr.ibm.com>
Cc: Dave Hansen <haveblue@us.ibm.com>
Cc: Herbert Poetzel <herbert@13thfloor.at>
Cc: Kirill Korotaev <dev@sw.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel/pid.c')
| -rw-r--r-- | kernel/pid.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/kernel/pid.c b/kernel/pid.c index 78c0dbffde65..bb0785109d39 100644 --- a/kernel/pid.c +++ b/kernel/pid.c @@ -70,6 +70,11 @@ struct pid_namespace init_pid_ns = { .child_reaper = &init_task }; +int is_global_init(struct task_struct *tsk) +{ + return tsk == init_pid_ns.child_reaper; +} + /* * Note: disable interrupts while the pidmap_lock is held as an * interrupt might come in and do read_lock(&tasklist_lock). |