mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-05 16:36:43 +07:00
603ba7e41b
Pull vfs pile #2 from Al Viro: "Next pile (and there'll be one or two more). The large piece in this one is getting rid of /proc/*/ns/* weirdness; among other things, it allows to (finally) make nameidata completely opaque outside of fs/namei.c, making for easier further cleanups in there" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: coda_venus_readdir(): use file_inode() fs/namei.c: fold link_path_walk() call into path_init() path_init(): don't bother with LOOKUP_PARENT in argument fs/namei.c: new helper (path_cleanup()) path_init(): store the "base" pointer to file in nameidata itself make default ->i_fop have ->open() fail with ENXIO make nameidata completely opaque outside of fs/namei.c kill proc_ns completely take the targets of /proc/*/ns/* symlinks to separate fs bury struct proc_ns in fs/proc copy address of proc_ns_ops into ns_common new helpers: ns_alloc_inum/ns_free_inum make proc_ns_operations work with struct ns_common * instead of void * switch the rest of proc_ns_operations to working with &...->ns netns: switch ->get()/->put()/->install()/->inum() to working with &net->ns make mntns ->get()/->put()/->install()/->inum() work with &mnt_ns->ns common object embedded into various struct ....ns
609 lines
15 KiB
C
609 lines
15 KiB
C
/*
|
|
* Generic pidhash and scalable, time-bounded PID allocator
|
|
*
|
|
* (C) 2002-2003 Nadia Yvette Chambers, IBM
|
|
* (C) 2004 Nadia Yvette Chambers, Oracle
|
|
* (C) 2002-2004 Ingo Molnar, Red Hat
|
|
*
|
|
* pid-structures are backing objects for tasks sharing a given ID to chain
|
|
* against. There is very little to them aside from hashing them and
|
|
* parking tasks using given ID's on a list.
|
|
*
|
|
* The hash is always changed with the tasklist_lock write-acquired,
|
|
* and the hash is only accessed with the tasklist_lock at least
|
|
* read-acquired, so there's no additional SMP locking needed here.
|
|
*
|
|
* We have a list of bitmap pages, which bitmaps represent the PID space.
|
|
* Allocating and freeing PIDs is completely lockless. The worst-case
|
|
* allocation scenario when all but one out of 1 million PIDs possible are
|
|
* allocated already: the scanning of 32 list entries and at most PAGE_SIZE
|
|
* bytes. The typical fastpath is a single successful setbit. Freeing is O(1).
|
|
*
|
|
* Pid namespaces:
|
|
* (C) 2007 Pavel Emelyanov <xemul@openvz.org>, OpenVZ, SWsoft Inc.
|
|
* (C) 2007 Sukadev Bhattiprolu <sukadev@us.ibm.com>, IBM
|
|
* Many thanks to Oleg Nesterov for comments and help
|
|
*
|
|
*/
|
|
|
|
#include <linux/mm.h>
|
|
#include <linux/export.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/init.h>
|
|
#include <linux/rculist.h>
|
|
#include <linux/bootmem.h>
|
|
#include <linux/hash.h>
|
|
#include <linux/pid_namespace.h>
|
|
#include <linux/init_task.h>
|
|
#include <linux/syscalls.h>
|
|
#include <linux/proc_ns.h>
|
|
#include <linux/proc_fs.h>
|
|
|
|
#define pid_hashfn(nr, ns) \
|
|
hash_long((unsigned long)nr + (unsigned long)ns, pidhash_shift)
|
|
static struct hlist_head *pid_hash;
|
|
static unsigned int pidhash_shift = 4;
|
|
struct pid init_struct_pid = INIT_STRUCT_PID;
|
|
|
|
int pid_max = PID_MAX_DEFAULT;
|
|
|
|
#define RESERVED_PIDS 300
|
|
|
|
int pid_max_min = RESERVED_PIDS + 1;
|
|
int pid_max_max = PID_MAX_LIMIT;
|
|
|
|
static inline int mk_pid(struct pid_namespace *pid_ns,
|
|
struct pidmap *map, int off)
|
|
{
|
|
return (map - pid_ns->pidmap)*BITS_PER_PAGE + off;
|
|
}
|
|
|
|
#define find_next_offset(map, off) \
|
|
find_next_zero_bit((map)->page, BITS_PER_PAGE, off)
|
|
|
|
/*
|
|
* PID-map pages start out as NULL, they get allocated upon
|
|
* first use and are never deallocated. This way a low pid_max
|
|
* value does not cause lots of bitmaps to be allocated, but
|
|
* the scheme scales to up to 4 million PIDs, runtime.
|
|
*/
|
|
struct pid_namespace init_pid_ns = {
|
|
.kref = {
|
|
.refcount = ATOMIC_INIT(2),
|
|
},
|
|
.pidmap = {
|
|
[ 0 ... PIDMAP_ENTRIES-1] = { ATOMIC_INIT(BITS_PER_PAGE), NULL }
|
|
},
|
|
.last_pid = 0,
|
|
.nr_hashed = PIDNS_HASH_ADDING,
|
|
.level = 0,
|
|
.child_reaper = &init_task,
|
|
.user_ns = &init_user_ns,
|
|
.ns.inum = PROC_PID_INIT_INO,
|
|
#ifdef CONFIG_PID_NS
|
|
.ns.ops = &pidns_operations,
|
|
#endif
|
|
};
|
|
EXPORT_SYMBOL_GPL(init_pid_ns);
|
|
|
|
/*
|
|
* Note: disable interrupts while the pidmap_lock is held as an
|
|
* interrupt might come in and do read_lock(&tasklist_lock).
|
|
*
|
|
* If we don't disable interrupts there is a nasty deadlock between
|
|
* detach_pid()->free_pid() and another cpu that does
|
|
* spin_lock(&pidmap_lock) followed by an interrupt routine that does
|
|
* read_lock(&tasklist_lock);
|
|
*
|
|
* After we clean up the tasklist_lock and know there are no
|
|
* irq handlers that take it we can leave the interrupts enabled.
|
|
* For now it is easier to be safe than to prove it can't happen.
|
|
*/
|
|
|
|
static __cacheline_aligned_in_smp DEFINE_SPINLOCK(pidmap_lock);
|
|
|
|
static void free_pidmap(struct upid *upid)
|
|
{
|
|
int nr = upid->nr;
|
|
struct pidmap *map = upid->ns->pidmap + nr / BITS_PER_PAGE;
|
|
int offset = nr & BITS_PER_PAGE_MASK;
|
|
|
|
clear_bit(offset, map->page);
|
|
atomic_inc(&map->nr_free);
|
|
}
|
|
|
|
/*
|
|
* If we started walking pids at 'base', is 'a' seen before 'b'?
|
|
*/
|
|
static int pid_before(int base, int a, int b)
|
|
{
|
|
/*
|
|
* This is the same as saying
|
|
*
|
|
* (a - base + MAXUINT) % MAXUINT < (b - base + MAXUINT) % MAXUINT
|
|
* and that mapping orders 'a' and 'b' with respect to 'base'.
|
|
*/
|
|
return (unsigned)(a - base) < (unsigned)(b - base);
|
|
}
|
|
|
|
/*
|
|
* We might be racing with someone else trying to set pid_ns->last_pid
|
|
* at the pid allocation time (there's also a sysctl for this, but racing
|
|
* with this one is OK, see comment in kernel/pid_namespace.c about it).
|
|
* We want the winner to have the "later" value, because if the
|
|
* "earlier" value prevails, then a pid may get reused immediately.
|
|
*
|
|
* Since pids rollover, it is not sufficient to just pick the bigger
|
|
* value. We have to consider where we started counting from.
|
|
*
|
|
* 'base' is the value of pid_ns->last_pid that we observed when
|
|
* we started looking for a pid.
|
|
*
|
|
* 'pid' is the pid that we eventually found.
|
|
*/
|
|
static void set_last_pid(struct pid_namespace *pid_ns, int base, int pid)
|
|
{
|
|
int prev;
|
|
int last_write = base;
|
|
do {
|
|
prev = last_write;
|
|
last_write = cmpxchg(&pid_ns->last_pid, prev, pid);
|
|
} while ((prev != last_write) && (pid_before(base, last_write, pid)));
|
|
}
|
|
|
|
static int alloc_pidmap(struct pid_namespace *pid_ns)
|
|
{
|
|
int i, offset, max_scan, pid, last = pid_ns->last_pid;
|
|
struct pidmap *map;
|
|
|
|
pid = last + 1;
|
|
if (pid >= pid_max)
|
|
pid = RESERVED_PIDS;
|
|
offset = pid & BITS_PER_PAGE_MASK;
|
|
map = &pid_ns->pidmap[pid/BITS_PER_PAGE];
|
|
/*
|
|
* If last_pid points into the middle of the map->page we
|
|
* want to scan this bitmap block twice, the second time
|
|
* we start with offset == 0 (or RESERVED_PIDS).
|
|
*/
|
|
max_scan = DIV_ROUND_UP(pid_max, BITS_PER_PAGE) - !offset;
|
|
for (i = 0; i <= max_scan; ++i) {
|
|
if (unlikely(!map->page)) {
|
|
void *page = kzalloc(PAGE_SIZE, GFP_KERNEL);
|
|
/*
|
|
* Free the page if someone raced with us
|
|
* installing it:
|
|
*/
|
|
spin_lock_irq(&pidmap_lock);
|
|
if (!map->page) {
|
|
map->page = page;
|
|
page = NULL;
|
|
}
|
|
spin_unlock_irq(&pidmap_lock);
|
|
kfree(page);
|
|
if (unlikely(!map->page))
|
|
break;
|
|
}
|
|
if (likely(atomic_read(&map->nr_free))) {
|
|
for ( ; ; ) {
|
|
if (!test_and_set_bit(offset, map->page)) {
|
|
atomic_dec(&map->nr_free);
|
|
set_last_pid(pid_ns, last, pid);
|
|
return pid;
|
|
}
|
|
offset = find_next_offset(map, offset);
|
|
if (offset >= BITS_PER_PAGE)
|
|
break;
|
|
pid = mk_pid(pid_ns, map, offset);
|
|
if (pid >= pid_max)
|
|
break;
|
|
}
|
|
}
|
|
if (map < &pid_ns->pidmap[(pid_max-1)/BITS_PER_PAGE]) {
|
|
++map;
|
|
offset = 0;
|
|
} else {
|
|
map = &pid_ns->pidmap[0];
|
|
offset = RESERVED_PIDS;
|
|
if (unlikely(last == offset))
|
|
break;
|
|
}
|
|
pid = mk_pid(pid_ns, map, offset);
|
|
}
|
|
return -1;
|
|
}
|
|
|
|
int next_pidmap(struct pid_namespace *pid_ns, unsigned int last)
|
|
{
|
|
int offset;
|
|
struct pidmap *map, *end;
|
|
|
|
if (last >= PID_MAX_LIMIT)
|
|
return -1;
|
|
|
|
offset = (last + 1) & BITS_PER_PAGE_MASK;
|
|
map = &pid_ns->pidmap[(last + 1)/BITS_PER_PAGE];
|
|
end = &pid_ns->pidmap[PIDMAP_ENTRIES];
|
|
for (; map < end; map++, offset = 0) {
|
|
if (unlikely(!map->page))
|
|
continue;
|
|
offset = find_next_bit((map)->page, BITS_PER_PAGE, offset);
|
|
if (offset < BITS_PER_PAGE)
|
|
return mk_pid(pid_ns, map, offset);
|
|
}
|
|
return -1;
|
|
}
|
|
|
|
void put_pid(struct pid *pid)
|
|
{
|
|
struct pid_namespace *ns;
|
|
|
|
if (!pid)
|
|
return;
|
|
|
|
ns = pid->numbers[pid->level].ns;
|
|
if ((atomic_read(&pid->count) == 1) ||
|
|
atomic_dec_and_test(&pid->count)) {
|
|
kmem_cache_free(ns->pid_cachep, pid);
|
|
put_pid_ns(ns);
|
|
}
|
|
}
|
|
EXPORT_SYMBOL_GPL(put_pid);
|
|
|
|
static void delayed_put_pid(struct rcu_head *rhp)
|
|
{
|
|
struct pid *pid = container_of(rhp, struct pid, rcu);
|
|
put_pid(pid);
|
|
}
|
|
|
|
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);
|
|
for (i = 0; i <= pid->level; i++) {
|
|
struct upid *upid = pid->numbers + i;
|
|
struct pid_namespace *ns = upid->ns;
|
|
hlist_del_rcu(&upid->pid_chain);
|
|
switch(--ns->nr_hashed) {
|
|
case 2:
|
|
case 1:
|
|
/* When all that is left in the pid namespace
|
|
* is the reaper wake up the reaper. The reaper
|
|
* may be sleeping in zap_pid_ns_processes().
|
|
*/
|
|
wake_up_process(ns->child_reaper);
|
|
break;
|
|
case PIDNS_HASH_ADDING:
|
|
/* Handle a fork failure of the first process */
|
|
WARN_ON(ns->child_reaper);
|
|
ns->nr_hashed = 0;
|
|
/* fall through */
|
|
case 0:
|
|
schedule_work(&ns->proc_work);
|
|
break;
|
|
}
|
|
}
|
|
spin_unlock_irqrestore(&pidmap_lock, flags);
|
|
|
|
for (i = 0; i <= pid->level; i++)
|
|
free_pidmap(pid->numbers + i);
|
|
|
|
call_rcu(&pid->rcu, delayed_put_pid);
|
|
}
|
|
|
|
struct pid *alloc_pid(struct pid_namespace *ns)
|
|
{
|
|
struct pid *pid;
|
|
enum pid_type type;
|
|
int i, nr;
|
|
struct pid_namespace *tmp;
|
|
struct upid *upid;
|
|
|
|
pid = kmem_cache_alloc(ns->pid_cachep, GFP_KERNEL);
|
|
if (!pid)
|
|
goto out;
|
|
|
|
tmp = ns;
|
|
pid->level = ns->level;
|
|
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 (unlikely(is_child_reaper(pid))) {
|
|
if (pid_ns_prepare_proc(ns))
|
|
goto out_free;
|
|
}
|
|
|
|
get_pid_ns(ns);
|
|
atomic_set(&pid->count, 1);
|
|
for (type = 0; type < PIDTYPE_MAX; ++type)
|
|
INIT_HLIST_HEAD(&pid->tasks[type]);
|
|
|
|
upid = pid->numbers + ns->level;
|
|
spin_lock_irq(&pidmap_lock);
|
|
if (!(ns->nr_hashed & PIDNS_HASH_ADDING))
|
|
goto out_unlock;
|
|
for ( ; upid >= pid->numbers; --upid) {
|
|
hlist_add_head_rcu(&upid->pid_chain,
|
|
&pid_hash[pid_hashfn(upid->nr, upid->ns)]);
|
|
upid->ns->nr_hashed++;
|
|
}
|
|
spin_unlock_irq(&pidmap_lock);
|
|
|
|
out:
|
|
return pid;
|
|
|
|
out_unlock:
|
|
spin_unlock_irq(&pidmap_lock);
|
|
put_pid_ns(ns);
|
|
|
|
out_free:
|
|
while (++i <= ns->level)
|
|
free_pidmap(pid->numbers + i);
|
|
|
|
kmem_cache_free(ns->pid_cachep, pid);
|
|
pid = NULL;
|
|
goto out;
|
|
}
|
|
|
|
void disable_pid_allocation(struct pid_namespace *ns)
|
|
{
|
|
spin_lock_irq(&pidmap_lock);
|
|
ns->nr_hashed &= ~PIDNS_HASH_ADDING;
|
|
spin_unlock_irq(&pidmap_lock);
|
|
}
|
|
|
|
struct pid *find_pid_ns(int nr, struct pid_namespace *ns)
|
|
{
|
|
struct upid *pnr;
|
|
|
|
hlist_for_each_entry_rcu(pnr,
|
|
&pid_hash[pid_hashfn(nr, ns)], pid_chain)
|
|
if (pnr->nr == nr && pnr->ns == ns)
|
|
return container_of(pnr, struct pid,
|
|
numbers[ns->level]);
|
|
|
|
return NULL;
|
|
}
|
|
EXPORT_SYMBOL_GPL(find_pid_ns);
|
|
|
|
struct pid *find_vpid(int nr)
|
|
{
|
|
return find_pid_ns(nr, task_active_pid_ns(current));
|
|
}
|
|
EXPORT_SYMBOL_GPL(find_vpid);
|
|
|
|
/*
|
|
* attach_pid() must be called with the tasklist_lock write-held.
|
|
*/
|
|
void attach_pid(struct task_struct *task, enum pid_type type)
|
|
{
|
|
struct pid_link *link = &task->pids[type];
|
|
hlist_add_head_rcu(&link->node, &link->pid->tasks[type]);
|
|
}
|
|
|
|
static void __change_pid(struct task_struct *task, enum pid_type type,
|
|
struct pid *new)
|
|
{
|
|
struct pid_link *link;
|
|
struct pid *pid;
|
|
int tmp;
|
|
|
|
link = &task->pids[type];
|
|
pid = link->pid;
|
|
|
|
hlist_del_rcu(&link->node);
|
|
link->pid = new;
|
|
|
|
for (tmp = PIDTYPE_MAX; --tmp >= 0; )
|
|
if (!hlist_empty(&pid->tasks[tmp]))
|
|
return;
|
|
|
|
free_pid(pid);
|
|
}
|
|
|
|
void detach_pid(struct task_struct *task, enum pid_type type)
|
|
{
|
|
__change_pid(task, type, NULL);
|
|
}
|
|
|
|
void change_pid(struct task_struct *task, enum pid_type type,
|
|
struct pid *pid)
|
|
{
|
|
__change_pid(task, type, pid);
|
|
attach_pid(task, type);
|
|
}
|
|
|
|
/* transfer_pid is an optimization of attach_pid(new), detach_pid(old) */
|
|
void transfer_pid(struct task_struct *old, struct task_struct *new,
|
|
enum pid_type type)
|
|
{
|
|
new->pids[type].pid = old->pids[type].pid;
|
|
hlist_replace_rcu(&old->pids[type].node, &new->pids[type].node);
|
|
}
|
|
|
|
struct task_struct *pid_task(struct pid *pid, enum pid_type type)
|
|
{
|
|
struct task_struct *result = NULL;
|
|
if (pid) {
|
|
struct hlist_node *first;
|
|
first = rcu_dereference_check(hlist_first_rcu(&pid->tasks[type]),
|
|
lockdep_tasklist_lock_is_held());
|
|
if (first)
|
|
result = hlist_entry(first, struct task_struct, pids[(type)].node);
|
|
}
|
|
return result;
|
|
}
|
|
EXPORT_SYMBOL(pid_task);
|
|
|
|
/*
|
|
* Must be called under rcu_read_lock().
|
|
*/
|
|
struct task_struct *find_task_by_pid_ns(pid_t nr, struct pid_namespace *ns)
|
|
{
|
|
rcu_lockdep_assert(rcu_read_lock_held(),
|
|
"find_task_by_pid_ns() needs rcu_read_lock()"
|
|
" protection");
|
|
return pid_task(find_pid_ns(nr, ns), PIDTYPE_PID);
|
|
}
|
|
|
|
struct task_struct *find_task_by_vpid(pid_t vnr)
|
|
{
|
|
return find_task_by_pid_ns(vnr, task_active_pid_ns(current));
|
|
}
|
|
|
|
struct pid *get_task_pid(struct task_struct *task, enum pid_type type)
|
|
{
|
|
struct pid *pid;
|
|
rcu_read_lock();
|
|
if (type != PIDTYPE_PID)
|
|
task = task->group_leader;
|
|
pid = get_pid(task->pids[type].pid);
|
|
rcu_read_unlock();
|
|
return pid;
|
|
}
|
|
EXPORT_SYMBOL_GPL(get_task_pid);
|
|
|
|
struct task_struct *get_pid_task(struct pid *pid, enum pid_type type)
|
|
{
|
|
struct task_struct *result;
|
|
rcu_read_lock();
|
|
result = pid_task(pid, type);
|
|
if (result)
|
|
get_task_struct(result);
|
|
rcu_read_unlock();
|
|
return result;
|
|
}
|
|
EXPORT_SYMBOL_GPL(get_pid_task);
|
|
|
|
struct pid *find_get_pid(pid_t nr)
|
|
{
|
|
struct pid *pid;
|
|
|
|
rcu_read_lock();
|
|
pid = get_pid(find_vpid(nr));
|
|
rcu_read_unlock();
|
|
|
|
return pid;
|
|
}
|
|
EXPORT_SYMBOL_GPL(find_get_pid);
|
|
|
|
pid_t pid_nr_ns(struct pid *pid, struct pid_namespace *ns)
|
|
{
|
|
struct upid *upid;
|
|
pid_t nr = 0;
|
|
|
|
if (pid && ns->level <= pid->level) {
|
|
upid = &pid->numbers[ns->level];
|
|
if (upid->ns == ns)
|
|
nr = upid->nr;
|
|
}
|
|
return nr;
|
|
}
|
|
EXPORT_SYMBOL_GPL(pid_nr_ns);
|
|
|
|
pid_t pid_vnr(struct pid *pid)
|
|
{
|
|
return pid_nr_ns(pid, task_active_pid_ns(current));
|
|
}
|
|
EXPORT_SYMBOL_GPL(pid_vnr);
|
|
|
|
pid_t __task_pid_nr_ns(struct task_struct *task, enum pid_type type,
|
|
struct pid_namespace *ns)
|
|
{
|
|
pid_t nr = 0;
|
|
|
|
rcu_read_lock();
|
|
if (!ns)
|
|
ns = task_active_pid_ns(current);
|
|
if (likely(pid_alive(task))) {
|
|
if (type != PIDTYPE_PID)
|
|
task = task->group_leader;
|
|
nr = pid_nr_ns(task->pids[type].pid, ns);
|
|
}
|
|
rcu_read_unlock();
|
|
|
|
return nr;
|
|
}
|
|
EXPORT_SYMBOL(__task_pid_nr_ns);
|
|
|
|
pid_t task_tgid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
|
|
{
|
|
return pid_nr_ns(task_tgid(tsk), ns);
|
|
}
|
|
EXPORT_SYMBOL(task_tgid_nr_ns);
|
|
|
|
struct pid_namespace *task_active_pid_ns(struct task_struct *tsk)
|
|
{
|
|
return ns_of_pid(task_pid(tsk));
|
|
}
|
|
EXPORT_SYMBOL_GPL(task_active_pid_ns);
|
|
|
|
/*
|
|
* Used by proc to find the first pid that is greater than or equal to nr.
|
|
*
|
|
* If there is a pid at nr this function is exactly the same as find_pid_ns.
|
|
*/
|
|
struct pid *find_ge_pid(int nr, struct pid_namespace *ns)
|
|
{
|
|
struct pid *pid;
|
|
|
|
do {
|
|
pid = find_pid_ns(nr, ns);
|
|
if (pid)
|
|
break;
|
|
nr = next_pidmap(ns, nr);
|
|
} while (nr > 0);
|
|
|
|
return pid;
|
|
}
|
|
|
|
/*
|
|
* The pid hash table is scaled according to the amount of memory in the
|
|
* machine. From a minimum of 16 slots up to 4096 slots at one gigabyte or
|
|
* more.
|
|
*/
|
|
void __init pidhash_init(void)
|
|
{
|
|
unsigned int i, pidhash_size;
|
|
|
|
pid_hash = alloc_large_system_hash("PID", sizeof(*pid_hash), 0, 18,
|
|
HASH_EARLY | HASH_SMALL,
|
|
&pidhash_shift, NULL,
|
|
0, 4096);
|
|
pidhash_size = 1U << pidhash_shift;
|
|
|
|
for (i = 0; i < pidhash_size; i++)
|
|
INIT_HLIST_HEAD(&pid_hash[i]);
|
|
}
|
|
|
|
void __init pidmap_init(void)
|
|
{
|
|
/* Veryify no one has done anything silly */
|
|
BUILD_BUG_ON(PID_MAX_LIMIT >= PIDNS_HASH_ADDING);
|
|
|
|
/* bump default and minimum pid_max based on number of cpus */
|
|
pid_max = min(pid_max_max, max_t(int, pid_max,
|
|
PIDS_PER_CPU_DEFAULT * num_possible_cpus()));
|
|
pid_max_min = max_t(int, pid_max_min,
|
|
PIDS_PER_CPU_MIN * num_possible_cpus());
|
|
pr_info("pid_max: default: %u minimum: %u\n", pid_max, pid_max_min);
|
|
|
|
init_pid_ns.pidmap[0].page = kzalloc(PAGE_SIZE, GFP_KERNEL);
|
|
/* Reserve PID 0. We never call free_pidmap(0) */
|
|
set_bit(0, init_pid_ns.pidmap[0].page);
|
|
atomic_dec(&init_pid_ns.pidmap[0].nr_free);
|
|
|
|
init_pid_ns.pid_cachep = KMEM_CACHE(pid,
|
|
SLAB_HWCACHE_ALIGN | SLAB_PANIC);
|
|
}
|