Gitweb:
http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=8ef047aaaeb811247a5639c92e2f2ae1221a28dd
Commit: 8ef047aaaeb811247a5639c92e2f2ae1221a28dd
Parent: faacbfd3a6808bf87d8f353b42eceeaba2c78a47
Author: Pavel Emelyanov <[EMAIL PROTECTED]>
AuthorDate: Thu Oct 18 23:40:05 2007 -0700
Committer: Linus Torvalds <[EMAIL PROTECTED]>
CommitDate: Fri Oct 19 11:53:39 2007 -0700
pid namespaces: make alloc_pid(), free_pid() and put_pid() work with struct
upid
Each struct upid element of struct pid has to be initialized properly, i.e.
its nr mst be allocated from appropriate pidmap and ns set to appropriate
namespace.
When allocating a new pid, we need to know the namespace this pid will live
in, so the additional argument is added to alloc_pid().
On the other hand, the rest of the kernel still uses the pid->nr and
pid->pid_chain fields, so these ones are still initialized, but this will be
removed soon.
Signed-off-by: Pavel Emelyanov <[EMAIL PROTECTED]>
Cc: Oleg Nesterov <[EMAIL PROTECTED]>
Cc: Sukadev Bhattiprolu <[EMAIL PROTECTED]>
Cc: Paul Menage <[EMAIL PROTECTED]>
Cc: "Eric W. Biederman" <[EMAIL PROTECTED]>
Signed-off-by: Andrew Morton <[EMAIL PROTECTED]>
Signed-off-by: Linus Torvalds <[EMAIL PROTECTED]>
---
include/linux/pid.h | 2 +-
kernel/fork.c | 2 +-
kernel/pid.c | 49 ++++++++++++++++++++++++++++++++++---------------
3 files changed, 36 insertions(+), 17 deletions(-)
diff --git a/include/linux/pid.h b/include/linux/pid.h
index e5865a9..67470ad 100644
--- a/include/linux/pid.h
+++ b/include/linux/pid.h
@@ -111,7 +111,7 @@ extern struct pid *FASTCALL(find_pid(int nr));
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 --git a/kernel/fork.c b/kernel/fork.c
index d2f4a42..984d259 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1041,7 +1041,7 @@ static struct task_struct *copy_process(unsigned long
clone_flags,
goto bad_fork_cleanup_put_domain;
if (pid != &init_struct_pid) {
- pid = alloc_pid();
+ pid = alloc_pid(task_active_pid_ns(p));
if (!pid)
goto bad_fork_put_binfmt_module;
}
diff --git a/kernel/pid.c b/kernel/pid.c
index c7346fb..8132a6d 100644
--- a/kernel/pid.c
+++ b/kernel/pid.c
@@ -29,7 +29,8 @@
#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;
@@ -186,11 +187,13 @@ 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);
@@ -203,45 +206,61 @@ static void delayed_put_pid(struct rcu_head *rhp)
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);
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;
+ pid->nr = pid->numbers[0].nr;
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)]);
+ hlist_add_head_rcu(&pid->pid_chain, &pid_hash[pid_hashfn(pid->nr, 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;
@@ -253,7 +272,7 @@ struct pid * fastcall find_pid(int nr)
struct pid *pid;
hlist_for_each_entry_rcu(pid, elem,
- &pid_hash[pid_hashfn(nr)], pid_chain) {
+ &pid_hash[pid_hashfn(nr, &init_pid_ns)], pid_chain) {
if (pid->nr == nr)
return pid;
}
-
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