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>
diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
index bf9e39c..9fb4a68 100644
--- a/arch/powerpc/kernel/traps.c
+++ b/arch/powerpc/kernel/traps.c
@@ -201,7 +201,7 @@
* generate the same exception over and over again and we get
* nowhere. Better to kill it and let the kernel panic.
*/
- if (is_init(current)) {
+ if (is_global_init(current)) {
__sighandler_t handler;
spin_lock_irq(¤t->sighand->siglock);
diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c
index ab3546c..a18fda3 100644
--- a/arch/powerpc/mm/fault.c
+++ b/arch/powerpc/mm/fault.c
@@ -375,7 +375,7 @@
*/
out_of_memory:
up_read(&mm->mmap_sem);
- if (is_init(current)) {
+ if (is_global_init(current)) {
yield();
down_read(&mm->mmap_sem);
goto survive;
diff --git a/arch/powerpc/platforms/pseries/ras.c b/arch/powerpc/platforms/pseries/ras.c
index 3a393c7..a1ab25c 100644
--- a/arch/powerpc/platforms/pseries/ras.c
+++ b/arch/powerpc/platforms/pseries/ras.c
@@ -332,7 +332,7 @@
err->disposition == RTAS_DISP_NOT_RECOVERED &&
err->target == RTAS_TARGET_MEMORY &&
err->type == RTAS_TYPE_ECC_UNCORR &&
- !(current->pid == 0 || is_init(current))) {
+ !(current->pid == 0 || is_global_init(current))) {
/* Kill off a user process with an ECC error */
printk(KERN_ERR "MCE: uncorrectable ecc error for pid %d\n",
current->pid);