diff options
Diffstat (limited to 'kernel/user.c')
| -rw-r--r-- | kernel/user.c | 50 |
1 files changed, 43 insertions, 7 deletions
diff --git a/kernel/user.c b/kernel/user.c index a2478cddf536..f46b1d41163b 100644 --- a/kernel/user.c +++ b/kernel/user.c @@ -18,41 +18,51 @@ #include <linux/interrupt.h> #include <linux/export.h> #include <linux/user_namespace.h> +#include <linux/binfmts.h> #include <linux/proc_ns.h> +#if IS_ENABLED(CONFIG_BINFMT_MISC) +struct binfmt_misc init_binfmt_misc = { + .entries = LIST_HEAD_INIT(init_binfmt_misc.entries), + .enabled = true, + .entries_lock = __RW_LOCK_UNLOCKED(init_binfmt_misc.entries_lock), +}; +EXPORT_SYMBOL_GPL(init_binfmt_misc); +#endif + /* * userns count is 1 for root user, 1 for init_uts_ns, * and 1 for... ? */ struct user_namespace init_user_ns = { .uid_map = { - .nr_extents = 1, { .extent[0] = { .first = 0, .lower_first = 0, .count = 4294967295U, }, + .nr_extents = 1, }, }, .gid_map = { - .nr_extents = 1, { .extent[0] = { .first = 0, .lower_first = 0, .count = 4294967295U, }, + .nr_extents = 1, }, }, .projid_map = { - .nr_extents = 1, { .extent[0] = { .first = 0, .lower_first = 0, .count = 4294967295U, }, + .nr_extents = 1, }, }, .ns.count = REFCOUNT_INIT(3), @@ -67,6 +77,9 @@ struct user_namespace init_user_ns = { .keyring_name_list = LIST_HEAD_INIT(init_user_ns.keyring_name_list), .keyring_sem = __RWSEM_INITIALIZER(init_user_ns.keyring_sem), #endif +#if IS_ENABLED(CONFIG_BINFMT_MISC) + .binfmt_misc = &init_binfmt_misc, +#endif }; EXPORT_SYMBOL_GPL(init_user_ns); @@ -75,7 +88,7 @@ EXPORT_SYMBOL_GPL(init_user_ns); * when changing user ID's (ie setuid() and friends). */ -#define UIDHASH_BITS (CONFIG_BASE_SMALL ? 3 : 7) +#define UIDHASH_BITS (IS_ENABLED(CONFIG_BASE_SMALL) ? 3 : 7) #define UIDHASH_SZ (1 << UIDHASH_BITS) #define UIDHASH_MASK (UIDHASH_SZ - 1) #define __uidhashfn(uid) (((uid >> UIDHASH_BITS) + uid) & UIDHASH_MASK) @@ -98,9 +111,6 @@ static DEFINE_SPINLOCK(uidhash_lock); /* root_user.__count is 1, for init task cred */ struct user_struct root_user = { .__count = REFCOUNT_INIT(1), - .processes = ATOMIC_INIT(1), - .sigpending = ATOMIC_INIT(0), - .locked_shm = 0, .uid = GLOBAL_ROOT_UID, .ratelimit = RATELIMIT_STATE_INIT(root_user.ratelimit, 0, 0), }; @@ -132,6 +142,22 @@ static struct user_struct *uid_hash_find(kuid_t uid, struct hlist_head *hashent) return NULL; } +static int user_epoll_alloc(struct user_struct *up) +{ +#ifdef CONFIG_EPOLL + return percpu_counter_init(&up->epoll_watches, 0, GFP_KERNEL); +#else + return 0; +#endif +} + +static void user_epoll_free(struct user_struct *up) +{ +#ifdef CONFIG_EPOLL + percpu_counter_destroy(&up->epoll_watches); +#endif +} + /* IRQs are disabled and uidhash_lock is held upon function entry. * IRQ state (as stored in flags) is restored and uidhash_lock released * upon function exit. @@ -141,6 +167,7 @@ static void free_user(struct user_struct *up, unsigned long flags) { uid_hash_remove(up); spin_unlock_irqrestore(&uidhash_lock, flags); + user_epoll_free(up); kmem_cache_free(uid_cachep, up); } @@ -171,6 +198,7 @@ void free_uid(struct user_struct *up) if (refcount_dec_and_lock_irqsave(&up->__count, &uidhash_lock, &flags)) free_user(up, flags); } +EXPORT_SYMBOL_GPL(free_uid); struct user_struct *alloc_uid(kuid_t uid) { @@ -188,6 +216,10 @@ struct user_struct *alloc_uid(kuid_t uid) new->uid = uid; refcount_set(&new->__count, 1); + if (user_epoll_alloc(new)) { + kmem_cache_free(uid_cachep, new); + return NULL; + } ratelimit_state_init(&new->ratelimit, HZ, 100); ratelimit_set_flags(&new->ratelimit, RATELIMIT_MSG_ON_RELEASE); @@ -198,6 +230,7 @@ struct user_struct *alloc_uid(kuid_t uid) spin_lock_irq(&uidhash_lock); up = uid_hash_find(uid, hashent); if (up) { + user_epoll_free(new); kmem_cache_free(uid_cachep, new); } else { uid_hash_insert(new, hashent); @@ -219,6 +252,9 @@ static int __init uid_cache_init(void) for(n = 0; n < UIDHASH_SZ; ++n) INIT_HLIST_HEAD(uidhash_table + n); + if (user_epoll_alloc(&root_user)) + panic("root_user epoll percpu counter alloc failed"); + /* Insert the root user immediately (init already runs as root) */ spin_lock_irq(&uidhash_lock); uid_hash_insert(&root_user, uidhashentry(GLOBAL_ROOT_UID)); |