Quoting sukadev@us.ibm.com (sukadev@us.ibm.com):
> 
> Subject: Define is_global_init()
> 
> From: Serge E. Hallyn <serue@us.ibm.com>
> 
> 
> is_init() is an ambiguous name for the pid==1 check.  Split it into
> is_global_init() and is_container_init().
> 
> A container 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.
> 
> Changelog:
> 
> 	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 container if the container's init has a
> 	  bug rather than force a kernel panic.
> 
> Signed-off-by: Serge E. Hallyn <serue@us.ibm.com>
> Signed-off-by: Sukadev Bhattiprolu <sukadev@us.ibm.com>
> ---
>  arch/alpha/mm/fault.c                |    2 +-
>  arch/arm/mm/fault.c                  |    2 +-
>  arch/arm26/mm/fault.c                |    2 +-
>  arch/avr32/kernel/traps.c            |    2 +-
>  arch/avr32/mm/fault.c                |    6 +++---
>  arch/i386/lib/usercopy.c             |    2 +-
>  arch/i386/mm/fault.c                 |    2 +-
>  arch/ia64/mm/fault.c                 |    2 +-
>  arch/m32r/mm/fault.c                 |    2 +-
>  arch/m68k/mm/fault.c                 |    2 +-
>  arch/mips/mm/fault.c                 |    2 +-
>  arch/powerpc/kernel/traps.c          |    2 +-
>  arch/powerpc/mm/fault.c              |    2 +-
>  arch/powerpc/platforms/pseries/ras.c |    2 +-
>  arch/ppc/kernel/traps.c              |    2 +-
>  arch/ppc/mm/fault.c                  |    2 +-
>  arch/s390/lib/uaccess_pt.c           |    2 +-
>  arch/s390/mm/fault.c                 |    2 +-
>  arch/sh/mm/fault.c                   |    2 +-
>  arch/sh64/mm/fault.c                 |    6 +++---
>  arch/um/kernel/trap.c                |    2 +-
>  arch/x86_64/mm/fault.c               |    4 ++--
>  arch/xtensa/mm/fault.c               |    2 +-
>  drivers/char/sysrq.c                 |    2 +-
>  include/linux/sched.h                |   13 +++----------
>  kernel/capability.c                  |    3 ++-
>  kernel/exit.c                        |    2 +-
>  kernel/kexec.c                       |    2 +-
>  kernel/pid.c                         |   21 +++++++++++++++++++++
>  kernel/sysctl.c                      |    2 +-
>  mm/oom_kill.c                        |    4 ++--
>  security/commoncap.c                 |    2 +-
>  32 files changed, 61 insertions(+), 46 deletions(-)
> 
> Index: lx26-21-mm2/arch/alpha/mm/fault.c
> ===================================================================
> --- lx26-21-mm2.orig/arch/alpha/mm/fault.c	2007-05-22 16:58:38.000000000 -0700
> +++ lx26-21-mm2/arch/alpha/mm/fault.c	2007-05-22 16:59:46.000000000 -0700
> @@ -192,7 +192,7 @@ do_page_fault(unsigned long address, uns
>  	/* We ran out of memory, or some other thing happened to us that
>  	   made us unable to handle the page fault gracefully.  */
>   out_of_memory:
> -	if (is_init(current)) {
> +	if (is_global_init(current)) {
>  		yield();
>  		down_read(&mm->mmap_sem);
>  		goto survive;
> Index: lx26-21-mm2/arch/arm/mm/fault.c
> ===================================================================
> --- lx26-21-mm2.orig/arch/arm/mm/fault.c	2007-05-22 16:58:38.000000000 -0700
> +++ lx26-21-mm2/arch/arm/mm/fault.c	2007-05-22 16:59:46.000000000 -0700
> @@ -197,7 +197,7 @@ survive:
>  		return fault;
>  	}
> 
> -	if (!is_init(tsk))
> +	if (!is_global_init(tsk))
>  		goto out;
> 
>  	/*
> Index: lx26-21-mm2/arch/arm26/mm/fault.c
> ===================================================================
> --- lx26-21-mm2.orig/arch/arm26/mm/fault.c	2007-05-22 16:58:38.000000000 -0700
> +++ lx26-21-mm2/arch/arm26/mm/fault.c	2007-05-22 16:59:46.000000000 -0700
> @@ -185,7 +185,7 @@ survive:
>  	}
> 
>  	fault = -3; /* out of memory */
> -	if (!is_init(tsk))
> +	if (!is_global_init(tsk))
>  		goto out;
> 
>  	/*
> Index: lx26-21-mm2/arch/i386/lib/usercopy.c
> ===================================================================
> --- lx26-21-mm2.orig/arch/i386/lib/usercopy.c	2007-05-22 16:58:38.000000000 -0700
> +++ lx26-21-mm2/arch/i386/lib/usercopy.c	2007-05-22 16:59:46.000000000 -0700
> @@ -748,7 +748,7 @@ survive:
>  			retval = get_user_pages(current, current->mm,
>  					(unsigned long )to, 1, 1, 0, &pg, NULL);
> 
> -			if (retval == -ENOMEM && is_init(current)) {
> +			if (retval == -ENOMEM && is_global_init(current)) {
>  				up_read(&current->mm->mmap_sem);
>  				congestion_wait(WRITE, HZ/50);
>  				goto survive;
> Index: lx26-21-mm2/arch/i386/mm/fault.c
> ===================================================================
> --- lx26-21-mm2.orig/arch/i386/mm/fault.c	2007-05-22 16:58:38.000000000 -0700
> +++ lx26-21-mm2/arch/i386/mm/fault.c	2007-05-22 16:59:46.000000000 -0700
> @@ -576,7 +576,7 @@ no_context:
>   */
>  out_of_memory:
>  	up_read(&mm->mmap_sem);
> -	if (is_init(tsk)) {
> +	if (is_global_init(tsk)) {
>  		yield();
>  		down_read(&mm->mmap_sem);
>  		goto survive;
> Index: lx26-21-mm2/arch/ia64/mm/fault.c
> ===================================================================
> --- lx26-21-mm2.orig/arch/ia64/mm/fault.c	2007-05-22 16:58:38.000000000 -0700
> +++ lx26-21-mm2/arch/ia64/mm/fault.c	2007-05-22 16:59:46.000000000 -0700
> @@ -279,7 +279,7 @@ ia64_do_page_fault (unsigned long addres
> 
>    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;
> Index: lx26-21-mm2/arch/m32r/mm/fault.c
> ===================================================================
> --- lx26-21-mm2.orig/arch/m32r/mm/fault.c	2007-05-22 16:58:38.000000000 -0700
> +++ lx26-21-mm2/arch/m32r/mm/fault.c	2007-05-22 16:59:46.000000000 -0700
> @@ -272,7 +272,7 @@ no_context:
>   */
>  out_of_memory:
>  	up_read(&mm->mmap_sem);
> -	if (is_init(tsk)) {
> +	if (is_global_init(tsk)) {
>  		yield();
>  		down_read(&mm->mmap_sem);
>  		goto survive;
> Index: lx26-21-mm2/arch/m68k/mm/fault.c
> ===================================================================
> --- lx26-21-mm2.orig/arch/m68k/mm/fault.c	2007-05-22 16:58:38.000000000 -0700
> +++ lx26-21-mm2/arch/m68k/mm/fault.c	2007-05-22 16:59:46.000000000 -0700
> @@ -181,7 +181,7 @@ good_area:
>   */
>  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;
> Index: lx26-21-mm2/arch/mips/mm/fault.c
> ===================================================================
> --- lx26-21-mm2.orig/arch/mips/mm/fault.c	2007-05-22 16:58:38.000000000 -0700
> +++ lx26-21-mm2/arch/mips/mm/fault.c	2007-05-22 16:59:46.000000000 -0700
> @@ -174,7 +174,7 @@ no_context:
>   */
>  out_of_memory:
>  	up_read(&mm->mmap_sem);
> -	if (is_init(tsk)) {
> +	if (is_global_init(tsk)) {
>  		yield();
>  		down_read(&mm->mmap_sem);
>  		goto survive;
> Index: lx26-21-mm2/arch/powerpc/kernel/traps.c
> ===================================================================
> --- lx26-21-mm2.orig/arch/powerpc/kernel/traps.c	2007-05-22 16:58:38.000000000 -0700
> +++ lx26-21-mm2/arch/powerpc/kernel/traps.c	2007-05-22 16:59:46.000000000 -0700
> @@ -190,7 +190,7 @@ void _exception(int signr, struct pt_reg
>  	 * 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(&current->sighand->siglock);
> Index: lx26-21-mm2/arch/powerpc/mm/fault.c
> ===================================================================
> --- lx26-21-mm2.orig/arch/powerpc/mm/fault.c	2007-05-22 16:58:38.000000000 -0700
> +++ lx26-21-mm2/arch/powerpc/mm/fault.c	2007-05-22 16:59:46.000000000 -0700
> @@ -374,7 +374,7 @@ bad_area_nosemaphore:
>   */
>  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;
> Index: lx26-21-mm2/arch/powerpc/platforms/pseries/ras.c
> ===================================================================
> --- lx26-21-mm2.orig/arch/powerpc/platforms/pseries/ras.c	2007-05-22 16:58:38.000000000 -0700
> +++ lx26-21-mm2/arch/powerpc/platforms/pseries/ras.c	2007-05-22 16:59:46.000000000 -0700
> @@ -332,7 +332,7 @@ static int recover_mce(struct pt_regs *r
>  		   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);
> Index: lx26-21-mm2/arch/ppc/kernel/traps.c
> ===================================================================
> --- lx26-21-mm2.orig/arch/ppc/kernel/traps.c	2007-05-22 16:58:38.000000000 -0700
> +++ lx26-21-mm2/arch/ppc/kernel/t