From b460cbc581a53cc088ceba80608021dd49c63c43 Mon Sep 17 00:00:00 2001 From: "Serge E. Hallyn" Date: Thu, 18 Oct 2007 23:39:52 -0700 Subject: 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 Signed-off-by: Sukadev Bhattiprolu Acked-by: Pavel Emelianov Cc: Eric W. Biederman Cc: Cedric Le Goater Cc: Dave Hansen Cc: Herbert Poetzel Cc: Kirill Korotaev Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/avr32/mm/fault.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'arch/avr32/mm') diff --git a/arch/avr32/mm/fault.c b/arch/avr32/mm/fault.c index 11472f8701bd..6560cb18b4e3 100644 --- a/arch/avr32/mm/fault.c +++ b/arch/avr32/mm/fault.c @@ -160,7 +160,7 @@ bad_area: if (exception_trace && printk_ratelimit()) printk("%s%s[%d]: segfault at %08lx pc %08lx " "sp %08lx ecr %lu\n", - is_init(tsk) ? KERN_EMERG : KERN_INFO, + is_global_init(tsk) ? KERN_EMERG : KERN_INFO, tsk->comm, tsk->pid, address, regs->pc, regs->sp, ecr); _exception(SIGSEGV, regs, code, address); @@ -209,7 +209,7 @@ no_context: */ 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; @@ -231,7 +231,7 @@ do_sigbus: if (exception_trace) printk("%s%s[%d]: bus error at %08lx pc %08lx " "sp %08lx ecr %lu\n", - is_init(tsk) ? KERN_EMERG : KERN_INFO, + is_global_init(tsk) ? KERN_EMERG : KERN_INFO, tsk->comm, tsk->pid, address, regs->pc, regs->sp, ecr); -- cgit v1.2.3