Each struct upid element of struct pid has to be initialized properly,
i.e. its nr mst be allocated from appropriate pidmap and it must be
inserted into the hash.

Signed-off-by: Pavel Emelyanov <[EMAIL PROTECTED]>

---

include/linux/pid.h |    2 +-
kernel/pid.c        |   52 +++++++++++++++++++++++++++++++++++++---------------
2 files changed, 38 insertions(+), 16 deletions(-)

diff -upr linux-2.6.23-rc1-mm1.orig/include/linux/pid.h 
linux-2.6.23-rc1-mm1-7/include/linux/pid.h
--- linux-2.6.23-rc1-mm1.orig/include/linux/pid.h       2007-07-26 
16:34:45.000000000 +0400
+++ linux-2.6.23-rc1-mm1-7/include/linux/pid.h  2007-07-26 16:36:37.000000000 
+0400
@@ -83,7 +92,7 @@ extern void FASTCALL(detach_pid(struct t
extern struct pid *find_get_pid(int nr);
extern struct pid *find_ge_pid(int nr);

-extern struct pid *alloc_pid(void);
+extern struct pid *alloc_pid(struct pid_namespace *ns);
extern void FASTCALL(free_pid(struct pid *pid));

static inline pid_t pid_nr(struct pid *pid)
diff -upr linux-2.6.23-rc1-mm1.orig/kernel/pid.c 
linux-2.6.23-rc1-mm1-7/kernel/pid.c
--- linux-2.6.23-rc1-mm1.orig/kernel/pid.c      2007-07-26 16:34:45.000000000 
+0400
+++ linux-2.6.23-rc1-mm1-7/kernel/pid.c 2007-07-26 16:36:37.000000000 +0400
@@ -28,7 +28,8 @@
#include <linux/pid_namespace.h>
#include <linux/init_task.h>

-#define pid_hashfn(nr) hash_long((unsigned long)nr, pidhash_shift)
+#define pid_hashfn(nr, ns)     \
+       hash_long((unsigned long)nr + (unsigned long)ns, pidhash_shift)
static struct hlist_head *pid_hash;
static int pidhash_shift;
struct pid init_struct_pid = INIT_STRUCT_PID;
@@ -187,11 +202,13 @@ fastcall void put_pid(struct pid *pid)
        if (!pid)
                return;

-       /* FIXME - this must be the namespace this pid lives in */
-       ns = &init_pid_ns;
+       ns = pid->numbers[pid->level].ns;
        if ((atomic_read(&pid->count) == 1) ||
-            atomic_dec_and_test(&pid->count))
+            atomic_dec_and_test(&pid->count)) {
                kmem_cache_free(ns->pid_cachep, pid);
+               if (ns != &init_pid_ns)
+                       put_pid_ns(ns);
+       }
}
EXPORT_SYMBOL_GPL(put_pid);

@@ -204,45 +221,64 @@ static void delayed_put_pid(struct rcu_h
fastcall void free_pid(struct pid *pid)
{
        /* We can be called with write_lock_irq(&tasklist_lock) held */
+       int i;
        unsigned long flags;

        spin_lock_irqsave(&pidmap_lock, flags);
-       hlist_del_rcu(&pid->pid_chain);
+       for (i = 0; i <= pid->level; i++)
+               hlist_del_rcu(&pid->numbers[i].pid_chain);
        spin_unlock_irqrestore(&pidmap_lock, flags);

-       free_pidmap(&init_pid_ns, pid->nr);
+       for (i = 0; i <= pid->level; i++)
+               free_pidmap(pid->numbers[i].ns, pid->numbers[i].nr);
+
        call_rcu(&pid->rcu, delayed_put_pid);
}

-struct pid *alloc_pid(void)
+struct pid *alloc_pid(struct pid_namespace *ns)
{
        struct pid *pid;
        enum pid_type type;
-       int nr = -1;
-       struct pid_namespace *ns;
+       int i, nr;
+       struct pid_namespace *tmp;

-       ns = task_active_pid_ns(current);
        pid = kmem_cache_alloc(ns->pid_cachep, GFP_KERNEL);
        if (!pid)
                goto out;

-       nr = alloc_pidmap(ns);
-       if (nr < 0)
-               goto out_free;
+       tmp = ns;
+       for (i = ns->level; i >= 0; i--) {
+               nr = alloc_pidmap(tmp);
+               if (nr < 0)
+                       goto out_free;
+
+               pid->numbers[i].nr = nr;
+               pid->numbers[i].ns = tmp;
+               tmp = tmp->parent;
+       }

+       if (ns != &init_pid_ns)
+               get_pid_ns(ns);
+
+       pid->level = ns->level;
        atomic_set(&pid->count, 1);
-       pid->nr = nr;
        for (type = 0; type < PIDTYPE_MAX; ++type)
                INIT_HLIST_HEAD(&pid->tasks[type]);

        spin_lock_irq(&pidmap_lock);
-       hlist_add_head_rcu(&pid->pid_chain, &pid_hash[pid_hashfn(pid->nr)]);
+       for (i = pid->level; i >= 0; i--)
+               hlist_add_head_rcu(&pid->numbers[i].pid_chain,
+                               &pid_hash[pid_hashfn(pid->numbers[i].nr,
+                                       pid->numbers[i].ns)]);
        spin_unlock_irq(&pidmap_lock);

out:
        return pid;

out_free:
+       for (i++; i <= ns->level; i++)
+               free_pidmap(pid->numbers[i].ns, pid->numbers[i].nr);
+
        kmem_cache_free(ns->pid_cachep, pid);
        pid = NULL;
        goto out;

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