linux/kernel/pid_namespace.c, branch v2.6.28

pid_ns: (BUG 11391) change ->child_reaper when init->group_leader exits

2008-09-03T02:21:38Z

We don't change pid_ns->child_reaper when the main thread of the subnamespace init exits. As Robert Rex pointed out this is wrong. Yes, the re-parenting itself works correctly, but if the reparented task exits it needs ->parent->nsproxy->pid_ns in do_notify_parent(), and if the main thread is zombie its ->nsproxy was already cleared by exit_task_namespaces(). Introduce the new function, find_new_reaper(), which finds the new ->parent for the re-parenting and changes ->child_reaper if needed. Kill the now unneeded exit_child_reaper(). Also move the changing of ->child_reaper from zap_pid_ns_processes() to find_new_reaper(), this consolidates the games with ->child_reaper and makes it stable under tasklist_lock. Addresses http://bugzilla.kernel.org/show_bug.cgi?id=11391 Reported-by: Robert Rex Signed-off-by: Oleg Nesterov Acked-by: Serge Hallyn Acked-by: Pavel Emelyanov Acked-by: Sukadev Bhattiprolu Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

pid_ns: zap_pid_ns_processes: fix the ->child_reaper changing

2008-09-03T02:21:38Z

zap_pid_ns_processes() sets pid_ns->child_reaper = NULL, this is wrong. Yes, we have already killed all tasks in this namespace, and sys_wait4() doesn't see any child. But this doesn't mean ->children list is empty, we may have EXIT_DEAD tasks which are not visible to do_wait(). In that case the subsequent forget_original_parent() will crash the kernel because it will try to re-parent these tasks to the NULL reaper. Even if there are no childs, it is not good that forget_original_parent() uses reaper == NULL. Change the code to set ->child_reaper = init_pid_ns.child_reaper instead. We could use pid_ns->parent->child_reaper as well, I think this does not really matter. These EXIT_DEAD tasks are not visible to the new ->parent after re-parenting, they will silently do release_task() eventually. Note that we must change ->child_reaper, otherwise forget_original_parent() will use reaper == father, and in that case we will hit the (correct) BUG_ON(!list_empty(&father->children)). Signed-off-by: Oleg Nesterov Acked-by: Serge Hallyn Acked-by: Sukadev Bhattiprolu Acked-by: Pavel Emelyanov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

bsdacct: switch from global bsd_acct_struct instance to per-pidns one

2008-07-25T17:53:47Z

Allocate the structure on the first call to sys_acct(). After this each namespace, that ordered the accounting, will live with this structure till its own death. Two notes - routines, that close the accounting on fs umount time use the init_pid_ns's acct by now; - accounting routine accounts to dying task's namespace (also by now). Signed-off-by: Pavel Emelyanov Cc: Balbir Singh Cc: "Eric W. Biederman" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

pidns: use kzalloc when allocating new pid_namespace struct

2008-07-25T17:53:46Z

It makes many fields initialization implicit helping in auto-setting #ifdef-ed fields (bsd-acct related pointer will be such). Signed-off-by: Pavel Emelyanov Cc: Balbir Singh Cc: "Eric W. Biederman" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

pidns: make pid->level and pid_ns->level unsigned

2008-04-30T15:29:49Z

These values represent the nesting level of a namespace and pids living in it, and it's always non-negative. Turning this from int to unsigned int saves some space in pid.c (11 bytes on x86 and 64 on ia64) by letting the compiler optimize the pid_nr_ns a bit. E.g. on ia64 this removes the sign extension calls, which compiler adds to optimize access to pid->nubers[ns->level]. Signed-off-by: Pavel Emelyanov Cc: "Eric W. Biederman" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

kernel: fix integer as NULL pointer warnings

2008-04-29T00:29:18Z

kernel/cpuset.c:1268:52: warning: Using plain integer as NULL pointer kernel/pid_namespace.c:95:24: warning: Using plain integer as NULL pointer Signed-off-by: Harvey Harrison Reviewed-by: Paul Jackson Signed-off-by: Linus Torvalds

namespaces: cleanup the code managed with PID_NS option

2008-02-08T17:22:23Z

Just like with the user namespaces, move the namespace management code into the separate .c file and mark the (already existing) PID_NS option as "depend on NAMESPACES" [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Pavel Emelyanov Acked-by: Serge Hallyn Cc: Cedric Le Goater Cc: "Eric W. Biederman" Cc: Herbert Poetzl Cc: Kirill Korotaev Cc: Sukadev Bhattiprolu Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds