X-Git-Url: http://git.rot13.org/?a=blobdiff_plain;f=kernel%2Fpid.c;h=2efe9d8d367b9346e1a38bc92027f0a24345029d;hb=df19b6b020791b4c42e7cf2e4f582454cbc49251;hp=373639a10d8456dce5998d8c6f949569edb1abcb;hpb=c88be3eb2e01bbb21c9ccdc3805f0d3546c1898c;p=powerpc.git diff --git a/kernel/pid.c b/kernel/pid.c index 373639a10d..2efe9d8d36 100644 --- a/kernel/pid.c +++ b/kernel/pid.c @@ -26,24 +26,29 @@ #include #include #include +#include #define pid_hashfn(nr) hash_long((unsigned long)nr, pidhash_shift) static struct hlist_head *pid_hash; static int pidhash_shift; -static kmem_cache_t *pid_cachep; +static struct kmem_cache *pid_cachep; int pid_max = PID_MAX_DEFAULT; -int last_pid; #define RESERVED_PIDS 300 int pid_max_min = RESERVED_PIDS + 1; int pid_max_max = PID_MAX_LIMIT; -#define PIDMAP_ENTRIES ((PID_MAX_LIMIT + 8*PAGE_SIZE - 1)/PAGE_SIZE/8) #define BITS_PER_PAGE (PAGE_SIZE*8) #define BITS_PER_PAGE_MASK (BITS_PER_PAGE-1) -#define mk_pid(map, off) (((map) - pidmap_array)*BITS_PER_PAGE + (off)) + +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) @@ -53,14 +58,17 @@ int pid_max_max = PID_MAX_LIMIT; * value does not cause lots of bitmaps to be allocated, but * the scheme scales to up to 4 million PIDs, runtime. */ -struct pidmap { - atomic_t nr_free; - void *page; +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, + .child_reaper = &init_task }; -static struct pidmap pidmap_array[PIDMAP_ENTRIES] = - { [ 0 ... PIDMAP_ENTRIES-1 ] = { ATOMIC_INIT(BITS_PER_PAGE), NULL } }; - /* * Note: disable interrupts while the pidmap_lock is held as an * interrupt might come in and do read_lock(&tasklist_lock). @@ -74,40 +82,41 @@ static struct pidmap pidmap_array[PIDMAP_ENTRIES] = * 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 fastcall void free_pidmap(int pid) +static fastcall void free_pidmap(struct pid_namespace *pid_ns, int pid) { - struct pidmap *map = pidmap_array + pid / BITS_PER_PAGE; + struct pidmap *map = pid_ns->pidmap + pid / BITS_PER_PAGE; int offset = pid & BITS_PER_PAGE_MASK; clear_bit(offset, map->page); atomic_inc(&map->nr_free); } -static int alloc_pidmap(void) +static int alloc_pidmap(struct pid_namespace *pid_ns) { - int i, offset, max_scan, pid, last = last_pid; + 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 = &pidmap_array[pid/BITS_PER_PAGE]; + map = &pid_ns->pidmap[pid/BITS_PER_PAGE]; max_scan = (pid_max + BITS_PER_PAGE - 1)/BITS_PER_PAGE - !offset; for (i = 0; i <= max_scan; ++i) { if (unlikely(!map->page)) { - unsigned long page = get_zeroed_page(GFP_KERNEL); + 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) - free_page(page); + kfree(page); else - map->page = (void *)page; + map->page = page; spin_unlock_irq(&pidmap_lock); if (unlikely(!map->page)) break; @@ -116,11 +125,11 @@ static int alloc_pidmap(void) do { if (!test_and_set_bit(offset, map->page)) { atomic_dec(&map->nr_free); - last_pid = pid; + pid_ns->last_pid = pid; return pid; } offset = find_next_offset(map, offset); - pid = mk_pid(map, offset); + pid = mk_pid(pid_ns, map, offset); /* * find_next_offset() found a bit, the pid from it * is in-bounds, and if we fell back to the last @@ -131,33 +140,34 @@ static int alloc_pidmap(void) (i != max_scan || pid < last || !((last+1) & BITS_PER_PAGE_MASK))); } - if (map < &pidmap_array[(pid_max-1)/BITS_PER_PAGE]) { + if (map < &pid_ns->pidmap[(pid_max-1)/BITS_PER_PAGE]) { ++map; offset = 0; } else { - map = &pidmap_array[0]; + map = &pid_ns->pidmap[0]; offset = RESERVED_PIDS; if (unlikely(last == offset)) break; } - pid = mk_pid(map, offset); + pid = mk_pid(pid_ns, map, offset); } return -1; } -static int next_pidmap(int last) +static int next_pidmap(struct pid_namespace *pid_ns, int last) { int offset; - struct pidmap *map; + struct pidmap *map, *end; offset = (last + 1) & BITS_PER_PAGE_MASK; - map = &pidmap_array[(last + 1)/BITS_PER_PAGE]; - for (; map < &pidmap_array[PIDMAP_ENTRIES]; map++, offset = 0) { + 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(map, offset); + return mk_pid(pid_ns, map, offset); } return -1; } @@ -187,7 +197,7 @@ fastcall void free_pid(struct pid *pid) hlist_del_rcu(&pid->pid_chain); spin_unlock_irqrestore(&pidmap_lock, flags); - free_pidmap(pid->nr); + free_pidmap(current->nsproxy->pid_ns, pid->nr); call_rcu(&pid->rcu, delayed_put_pid); } @@ -201,7 +211,7 @@ struct pid *alloc_pid(void) if (!pid) goto out; - nr = alloc_pidmap(); + nr = alloc_pidmap(current->nsproxy->pid_ns); if (nr < 0) goto out_free; @@ -299,6 +309,15 @@ struct task_struct *find_task_by_pid_type(int type, int nr) EXPORT_SYMBOL(find_task_by_pid_type); +struct pid *get_task_pid(struct task_struct *task, enum pid_type type) +{ + struct pid *pid; + rcu_read_lock(); + pid = get_pid(task->pids[type].pid); + rcu_read_unlock(); + return pid; +} + struct task_struct *fastcall get_pid_task(struct pid *pid, enum pid_type type) { struct task_struct *result; @@ -334,13 +353,33 @@ struct pid *find_ge_pid(int nr) pid = find_pid(nr); if (pid) break; - nr = next_pidmap(nr); + nr = next_pidmap(current->nsproxy->pid_ns, nr); } while (nr > 0); return pid; } EXPORT_SYMBOL_GPL(find_get_pid); +int copy_pid_ns(int flags, struct task_struct *tsk) +{ + struct pid_namespace *old_ns = tsk->nsproxy->pid_ns; + int err = 0; + + if (!old_ns) + return 0; + + get_pid_ns(old_ns); + return err; +} + +void free_pid_ns(struct kref *kref) +{ + struct pid_namespace *ns; + + ns = container_of(kref, struct pid_namespace, kref); + kfree(ns); +} + /* * 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 @@ -368,10 +407,10 @@ void __init pidhash_init(void) void __init pidmap_init(void) { - pidmap_array->page = (void *)get_zeroed_page(GFP_KERNEL); + init_pid_ns.pidmap[0].page = kzalloc(PAGE_SIZE, GFP_KERNEL); /* Reserve PID 0. We never call free_pidmap(0) */ - set_bit(0, pidmap_array->page); - atomic_dec(&pidmap_array->nr_free); + set_bit(0, init_pid_ns.pidmap[0].page); + atomic_dec(&init_pid_ns.pidmap[0].nr_free); pid_cachep = kmem_cache_create("pid", sizeof(struct pid), __alignof__(struct pid),