diff options
Diffstat (limited to 'kernel')
54 files changed, 4491 insertions, 2470 deletions
diff --git a/kernel/Makefile b/kernel/Makefile index cb41b9547c9f..6c07f30fa9b7 100644 --- a/kernel/Makefile +++ b/kernel/Makefile @@ -43,6 +43,7 @@ obj-$(CONFIG_DEBUG_RT_MUTEXES) += rtmutex-debug.o obj-$(CONFIG_RT_MUTEX_TESTER) += rtmutex-tester.o obj-$(CONFIG_GENERIC_ISA_DMA) += dma.o obj-$(CONFIG_SMP) += smp.o +obj-$(CONFIG_SMP) += smpboot.o ifneq ($(CONFIG_SMP),y) obj-y += up.o endif diff --git a/kernel/auditsc.c b/kernel/auditsc.c index af1de0f34eae..4b96415527b8 100644 --- a/kernel/auditsc.c +++ b/kernel/auditsc.c @@ -67,6 +67,7 @@ #include <linux/syscalls.h> #include <linux/capability.h> #include <linux/fs_struct.h> +#include <linux/compat.h> #include "audit.h" @@ -2710,13 +2711,16 @@ void audit_core_dumps(long signr) audit_log_end(ab); } -void __audit_seccomp(unsigned long syscall) +void __audit_seccomp(unsigned long syscall, long signr, int code) { struct audit_buffer *ab; ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_ANOM_ABEND); - audit_log_abend(ab, "seccomp", SIGKILL); + audit_log_abend(ab, "seccomp", signr); audit_log_format(ab, " syscall=%ld", syscall); + audit_log_format(ab, " compat=%d", is_compat_task()); + audit_log_format(ab, " ip=0x%lx", KSTK_EIP(current)); + audit_log_format(ab, " code=0x%x", code); audit_log_end(ab); } diff --git a/kernel/cgroup.c b/kernel/cgroup.c index ed64ccac67c9..ad8eae5bb801 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -60,9 +60,13 @@ #include <linux/eventfd.h> #include <linux/poll.h> #include <linux/flex_array.h> /* used in cgroup_attach_proc */ +#include <linux/kthread.h> #include <linux/atomic.h> +/* css deactivation bias, makes css->refcnt negative to deny new trygets */ +#define CSS_DEACT_BIAS INT_MIN + /* * cgroup_mutex is the master lock. Any modification to cgroup or its * hierarchy must be performed while holding it. @@ -127,6 +131,9 @@ struct cgroupfs_root { /* A list running through the active hierarchies */ struct list_head root_list; + /* All cgroups on this root, cgroup_mutex protected */ + struct list_head allcg_list; + /* Hierarchy-specific flags */ unsigned long flags; @@ -145,6 +152,15 @@ struct cgroupfs_root { static struct cgroupfs_root rootnode; /* + * cgroupfs file entry, pointed to from leaf dentry->d_fsdata. + */ +struct cfent { + struct list_head node; + struct dentry *dentry; + struct cftype *type; +}; + +/* * CSS ID -- ID per subsys's Cgroup Subsys State(CSS). used only when * cgroup_subsys->use_id != 0. */ @@ -239,6 +255,14 @@ int cgroup_lock_is_held(void) EXPORT_SYMBOL_GPL(cgroup_lock_is_held); +/* the current nr of refs, always >= 0 whether @css is deactivated or not */ +static int css_refcnt(struct cgroup_subsys_state *css) +{ + int v = atomic_read(&css->refcnt); + + return v >= 0 ? v : v - CSS_DEACT_BIAS; +} + /* convenient tests for these bits */ inline int cgroup_is_removed(const struct cgroup *cgrp) { @@ -279,6 +303,21 @@ list_for_each_entry(_ss, &_root->subsys_list, sibling) #define for_each_active_root(_root) \ list_for_each_entry(_root, &roots, root_list) +static inline struct cgroup *__d_cgrp(struct dentry *dentry) +{ + return dentry->d_fsdata; +} + +static inline struct cfent *__d_cfe(struct dentry *dentry) +{ + return dentry->d_fsdata; +} + +static inline struct cftype *__d_cft(struct dentry *dentry) +{ + return __d_cfe(dentry)->type; +} + /* the list of cgroups eligible for automatic release. Protected by * release_list_lock */ static LIST_HEAD(release_list); @@ -816,12 +855,17 @@ static int cgroup_call_pre_destroy(struct cgroup *cgrp) struct cgroup_subsys *ss; int ret = 0; - for_each_subsys(cgrp->root, ss) - if (ss->pre_destroy) { - ret = ss->pre_destroy(cgrp); - if (ret) - break; + for_each_subsys(cgrp->root, ss) { + if (!ss->pre_destroy) + continue; + + ret = ss->pre_destroy(cgrp); + if (ret) { + /* ->pre_destroy() failure is being deprecated */ + WARN_ON_ONCE(!ss->__DEPRECATED_clear_css_refs); + break; } + } return ret; } @@ -864,6 +908,14 @@ static void cgroup_diput(struct dentry *dentry, struct inode *inode) BUG_ON(!list_empty(&cgrp->pidlists)); kfree_rcu(cgrp, rcu_head); + } else { + struct cfent *cfe = __d_cfe(dentry); + struct cgroup *cgrp = dentry->d_parent->d_fsdata; + + WARN_ONCE(!list_empty(&cfe->node) && + cgrp != &cgrp->root->top_cgroup, + "cfe still linked for %s\n", cfe->type->name); + kfree(cfe); } iput(inode); } @@ -882,34 +934,36 @@ static void remove_dir(struct dentry *d) dput(parent); } -static void cgroup_clear_directory(struct dentry *dentry) -{ - struct list_head *node; - - BUG_ON(!mutex_is_locked(&dentry->d_inode->i_mutex)); - spin_lock(&dentry->d_lock); - node = dentry->d_subdirs.next; - while (node != &dentry->d_subdirs) { - struct dentry *d = list_entry(node, struct dentry, d_u.d_child); - - spin_lock_nested(&d->d_lock, DENTRY_D_LOCK_NESTED); - list_del_init(node); - if (d->d_inode) { - /* This should never be called on a cgroup - * directory with child cgroups */ - BUG_ON(d->d_inode->i_mode & S_IFDIR); - dget_dlock(d); - spin_unlock(&d->d_lock); - spin_unlock(&dentry->d_lock); - d_delete(d); - simple_unlink(dentry->d_inode, d); - dput(d); - spin_lock(&dentry->d_lock); - } else - spin_unlock(&d->d_lock); - node = dentry->d_subdirs.next; +static int cgroup_rm_file(struct cgroup *cgrp, const struct cftype *cft) +{ + struct cfent *cfe; + + lockdep_assert_held(&cgrp->dentry->d_inode->i_mutex); + lockdep_assert_held(&cgroup_mutex); + + list_for_each_entry(cfe, &cgrp->files, node) { + struct dentry *d = cfe->dentry; + + if (cft && cfe->type != cft) + continue; + + dget(d); + d_delete(d); + simple_unlink(d->d_inode, d); + list_del_init(&cfe->node); + dput(d); + + return 0; } - spin_unlock(&dentry->d_lock); + return -ENOENT; +} + +static void cgroup_clear_directory(struct dentry *dir) +{ + struct cgroup *cgrp = __d_cgrp(dir); + + while (!list_empty(&cgrp->files)) + cgroup_rm_file(cgrp, NULL); } /* @@ -1294,6 +1348,11 @@ static int cgroup_remount(struct super_block *sb, int *flags, char *data) if (ret) goto out_unlock; + /* See feature-removal-schedule.txt */ + if (opts.subsys_bits != root->actual_subsys_bits || opts.release_agent) + pr_warning("cgroup: option changes via remount are deprecated (pid=%d comm=%s)\n", + task_tgid_nr(current), current->comm); + /* Don't allow flags or name to change at remount */ if (opts.flags != root->flags || (opts.name && strcmp(opts.name, root->name))) { @@ -1308,7 +1367,8 @@ static int cgroup_remount(struct super_block *sb, int *flags, char *data) goto out_unlock; } - /* (re)populate subsystem files */ + /* clear out any existing files and repopulate subsystem files */ + cgroup_clear_directory(cgrp->dentry); cgroup_populate_dir(cgrp); if (opts.release_agent) @@ -1333,6 +1393,7 @@ static void init_cgroup_housekeeping(struct cgroup *cgrp) { INIT_LIST_HEAD(&cgrp->sibling); INIT_LIST_HEAD(&cgrp->children); + INIT_LIST_HEAD(&cgrp->files); INIT_LIST_HEAD(&cgrp->css_sets); INIT_LIST_HEAD(&cgrp->release_list); INIT_LIST_HEAD(&cgrp->pidlists); @@ -1344,11 +1405,14 @@ static void init_cgroup_housekeeping(struct cgroup *cgrp) static void init_cgroup_root(struct cgroupfs_root *root) { struct cgroup *cgrp = &root->top_cgroup; + INIT_LIST_HEAD(&root->subsys_list); INIT_LIST_HEAD(&root->root_list); + INIT_LIST_HEAD(&root->allcg_list); root->number_of_cgroups = 1; cgrp->root = root; cgrp->top_cgroup = cgrp; + list_add_tail(&cgrp->allcg_node, &root->allcg_list); init_cgroup_housekeeping(cgrp); } @@ -1692,16 +1756,6 @@ static struct file_system_type cgroup_fs_type = { static struct kobject *cgroup_kobj; -static inline struct cgroup *__d_cgrp(struct dentry *dentry) -{ - return dentry->d_fsdata; -} - -static inline struct cftype *__d_cft(struct dentry *dentry) -{ - return dentry->d_fsdata; -} - /** * cgroup_path - generate the path of a cgroup * @cgrp: the cgroup in question @@ -2172,6 +2226,18 @@ retry_find_task: if (threadgroup) tsk = tsk->group_leader; + + /* + * Workqueue threads may acquire PF_THREAD_BOUND and become + * trapped in a cpuset, or RT worker may be born in a cgroup + * with no rt_runtime allocated. Just say no. + */ + if (tsk == kthreadd_task || (tsk->flags & PF_THREAD_BOUND)) { + ret = -EINVAL; + rcu_read_unlock(); + goto out_unlock_cgroup; + } + get_task_struct(tsk); rcu_read_unlock(); @@ -2603,50 +2669,191 @@ static umode_t cgroup_file_mode(const struct cftype *cft) return mode; } -int cgroup_add_file(struct cgroup *cgrp, - struct cgroup_subsys *subsys, - const struct cftype *cft) +static int cgroup_add_file(struct cgroup *cgrp, struct cgroup_subsys *subsys, + const struct cftype *cft) { struct dentry *dir = cgrp->dentry; + struct cgroup *parent = __d_cgrp(dir); struct dentry *dentry; + struct cfent *cfe; int error; umode_t mode; - char name[MAX_CGROUP_TYPE_NAMELEN + MAX_CFTYPE_NAME + 2] = { 0 }; + + /* does @cft->flags tell us to skip creation on @cgrp? */ + if ((cft->flags & CFTYPE_NOT_ON_ROOT) && !cgrp->parent) + return 0; + if ((cft->flags & CFTYPE_ONLY_ON_ROOT) && cgrp->parent) + return 0; + if (subsys && !test_bit(ROOT_NOPREFIX, &cgrp->root->flags)) { strcpy(name, subsys->name); strcat(name, "."); } strcat(name, cft->name); + BUG_ON(!mutex_is_locked(&dir->d_inode->i_mutex)); + + cfe = kzalloc(sizeof(*cfe), GFP_KERNEL); + if (!cfe) + return -ENOMEM; + dentry = lookup_one_len(name, dir, strlen(name)); - if (!IS_ERR(dentry)) { - mode = cgroup_file_mode(cft); - error = cgroup_create_file(dentry, mode | S_IFREG, - cgrp->root->sb); - if (!error) - dentry->d_fsdata = (void *)cft; - dput(dentry); - } else + if (IS_ERR(dentry)) { error = PTR_ERR(dentry); + goto out; + } + + mode = cgroup_file_mode(cft); + error = cgroup_create_file(dentry, mode | S_IFREG, cgrp->root->sb); + if (!error) { + cfe->type = (void *)cft; + cfe->dentry = dentry; + dentry->d_fsdata = cfe; + list_add_tail(&cfe->node, &parent->files); + cfe = NULL; + } + dput(dentry); +out: + kfree(cfe); return error; } -EXPORT_SYMBOL_GPL(cgroup_add_file); -int cgroup_add_files(struct cgroup *cgrp, - struct cgroup_subsys *subsys, - const struct cftype cft[], - int count) +static int cgroup_addrm_files(struct cgroup *cgrp, struct cgroup_subsys *subsys, + const struct cftype cfts[], bool is_add) { - int i, err; - for (i = 0; i < count; i++) { - err = cgroup_add_file(cgrp, subsys, &cft[i]); - if (err) - return err; + const struct cftype *cft; + int err, ret = 0; + + for (cft = cfts; cft->name[0] != '\0'; cft++) { + if (is_add) + err = cgroup_add_file(cgrp, subsys, cft); + else + err = cgroup_rm_file(cgrp, cft); + if (err) { + pr_warning("cgroup_addrm_files: failed to %s %s, err=%d\n", + is_add ? "add" : "remove", cft->name, err); + ret = err; + } + } + return ret; +} + +static DEFINE_MUTEX(cgroup_cft_mutex); + +static void cgroup_cfts_prepare(void) + __acquires(&cgroup_cft_mutex) __acquires(&cgroup_mutex) +{ + /* + * Thanks to the entanglement with vfs inode locking, we can't walk + * the existing cgroups under cgroup_mutex and create files. + * Instead, we increment reference on all cgroups and build list of + * them using @cgrp->cft_q_node. Grab cgroup_cft_mutex to ensure + * exclusive access to the field. + */ + mutex_lock(&cgroup_cft_mutex); + mutex_lock(&cgroup_mutex); +} + +static void cgroup_cfts_commit(struct cgroup_subsys *ss, + const struct cftype *cfts, bool is_add) + __releases(&cgroup_mutex) __releases(&cgroup_cft_mutex) +{ + LIST_HEAD(pending); + struct cgroup *cgrp, *n; + + /* %NULL @cfts indicates abort and don't bother if @ss isn't attached */ + if (cfts && ss->root != &rootnode) { + list_for_each_entry(cgrp, &ss->root->allcg_list, allcg_node) { + dget(cgrp->dentry); + list_add_tail(&cgrp->cft_q_node, &pending); + } + } + + mutex_unlock(&cgroup_mutex); + + /* + * All new cgroups will see @cfts update on @ss->cftsets. Add/rm + * files for all cgroups which were created before. + */ + list_for_each_entry_safe(cgrp, n, &pending, cft_q_node) { + struct inode *inode = cgrp->dentry->d_inode; + + mutex_lock(&inode->i_mutex); + mutex_lock(&cgroup_mutex); + if (!cgroup_is_removed(cgrp)) + cgroup_addrm_files(cgrp, ss, cfts, is_add); + mutex_unlock(&cgroup_mutex); + mutex_unlock(&inode->i_mutex); + + list_del_init(&cgrp->cft_q_node); + dput(cgrp->dentry); } + + mutex_unlock(&cgroup_cft_mutex); +} + +/** + * cgroup_add_cftypes - add an array of cftypes to a subsystem + * @ss: target cgroup subsystem + * @cfts: zero-length name terminated array of cftypes + * + * Register @cfts to @ss. Files described by @cfts are created for all + * existing cgroups to which @ss is attached and all future cgroups will + * have them too. This function can be called anytime whether @ss is + * attached or not. + * + * Returns 0 on successful registration, -errno on failure. Note that this + * function currently returns 0 as long as @cfts registration is successful + * even if some file creation attempts on existing cgroups fail. + */ +int cgroup_add_cftypes(struct cgroup_subsys *ss, const struct cftype *cfts) +{ + struct cftype_set *set; + + set = kzalloc(sizeof(*set), GFP_KERNEL); + if (!set) + return -ENOMEM; + + cgroup_cfts_prepare(); + set->cfts = cfts; + list_add_tail(&set->node, &ss->cftsets); + cgroup_cfts_commit(ss, cfts, true); + return 0; } -EXPORT_SYMBOL_GPL(cgroup_add_files); +EXPORT_SYMBOL_GPL(cgroup_add_cftypes); + +/** + * cgroup_rm_cftypes - remove an array of cftypes from a subsystem + * @ss: target cgroup subsystem + * @cfts: zero-length name terminated array of cftypes + * + * Unregister @cfts from @ss. Files described by @cfts are removed from + * all existing cgroups to which @ss is attached and all future cgroups + * won't have them either. This function can be called anytime whether @ss + * is attached or not. + * + * Returns 0 on successful unregistration, -ENOENT if @cfts is not + * registered with @ss. + */ +int cgroup_rm_cftypes(struct cgroup_subsys *ss, const struct cftype *cfts) +{ + struct cftype_set *set; + + cgroup_cfts_prepare(); + + list_for_each_entry(set, &ss->cftsets, node) { + if (set->cfts == cfts) { + list_del_init(&set->node); + cgroup_cfts_commit(ss, cfts, false); + return 0; + } + } + + cgroup_cfts_commit(ss, NULL, false); + return -ENOENT; +} /** * cgroup_task_count - count the number of tasks in a cgroup. @@ -3625,13 +3832,14 @@ static struct cftype files[] = { .read_u64 = cgroup_clone_children_read, .write_u64 = cgroup_clone_children_write, }, -}; - -static struct cftype cft_release_agent = { - .name = "release_agent", - .read_seq_string = cgroup_release_agent_show, - .write_string = cgroup_release_agent_write, - .max_write_len = PATH_MAX, + { + .name = "release_agent", + .flags = CFTYPE_ONLY_ON_ROOT, + .read_seq_string = cgroup_release_agent_show, + .write_string = cgroup_release_agent_write, + .max_write_len = PATH_MAX, + }, + { } /* terminate */ }; static int cgroup_populate_dir(struct cgroup *cgrp) @@ -3639,22 +3847,18 @@ static int cgroup_populate_dir(struct cgroup *cgrp) int err; struct cgroup_subsys *ss; - /* First clear out any existing files */ - cgroup_clear_directory(cgrp->dentry); - - err = cgroup_add_files(cgrp, NULL, files, ARRAY_SIZE(files)); + err = cgroup_addrm_files(cgrp, NULL, files, true); if (err < 0) return err; - if (cgrp == cgrp->top_cgroup) { - if ((err = cgroup_add_file(cgrp, NULL, &cft_release_agent)) < 0) - return err; - } - + /* process cftsets of each subsystem */ for_each_subsys(cgrp->root, ss) { - if (ss->populate && (err = ss->populate(ss, cgrp)) < 0) - return err; + struct cftype_set *set; + + list_for_each_entry(set, &ss->cftsets, node) + cgroup_addrm_files(cgrp, ss, set->cfts, true); } + /* This cgroup is ready now */ for_each_subsys(cgrp->root, ss) { struct cgroup_subsys_state *css = cgrp->subsys[ss->subsys_id]; @@ -3670,6 +3874,14 @@ static int cgroup_populate_dir(struct cgroup *cgrp) return 0; } +static void css_dput_fn(struct work_struct *work) +{ + struct cgroup_subsys_state *css = + container_of(work, struct cgroup_subsys_state, dput_work); + + dput(css->cgroup->dentry); +} + static void init_cgroup_css(struct cgroup_subsys_state *css, struct cgroup_subsys *ss, struct cgroup *cgrp) @@ -3682,6 +3894,16 @@ static void init_cgroup_css(struct cgroup_subsys_state *css, set_bit(CSS_ROOT, &css->flags); BUG_ON(cgrp->subsys[ss->subsys_id]); cgrp->subsys[ss->subsys_id] = css; + + /* + * If !clear_css_refs, css holds an extra ref to @cgrp->dentry + * which is put on the last css_put(). dput() requires process + * context, which css_put() may be called without. @css->dput_work + * will be used to invoke dput() asynchronously from css_put(). + */ + INIT_WORK(&css->dput_work, css_dput_fn); + if (ss->__DEPRECATED_clear_css_refs) + set_bit(CSS_CLEAR_CSS_REFS, &css->flags); } static void cgroup_lock_hierarchy(struct cgroupfs_root *root) @@ -3784,9 +4006,16 @@ static long cgroup_create(struct cgroup *parent, struct dentry *dentry, if (err < 0) goto err_remove; + /* If !clear_css_refs, each css holds a ref to the cgroup's dentry */ + for_each_subsys(root, ss) + if (!ss->__DEPRECATED_clear_css_refs) + dget(dentry); + /* The cgroup directory was pre-locked for us */ BUG_ON(!mutex_is_locked(&cgrp->dentry->d_inode->i_mutex)); + list_add_tail(&cgrp->allcg_node, &root->allcg_list); + err = cgroup_populate_dir(cgrp); /* If err < 0, we have a half-filled directory - oh well ;) */ @@ -3826,18 +4055,19 @@ static int cgroup_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode) return cgroup_create(c_parent, dentry, mode | S_IFDIR); } +/* + * Check the reference count on each subsystem. Since we already + * established that there are no tasks in the cgroup, if the css refcount + * is also 1, then there should be no outstanding references, so the + * subsystem is safe to destroy. We scan across all subsystems rather than + * using the per-hierarchy linked list of mounted subsystems since we can + * be called via check_for_release() with no synchronization other than + * RCU, and the subsystem linked list isn't RCU-safe. + */ static int cgroup_has_css_refs(struct cgroup *cgrp) { - /* Check the reference count on each subsystem. Since we - * already established that there are no tasks in the - * cgroup, if the css refcount is also 1, then there should - * be no outstanding references, so the subsystem is safe to - * destroy. We scan across all subsystems rather than using - * the per-hierarchy linked list of mounted subsystems since - * we can be called via check_for_release() with no - * synchronization other than RCU, and the subsystem linked - * list isn't RCU-safe */ int i; + /* * We won't need to lock the subsys array, because the subsystems * we're concerned about aren't going anywhere since our cgroup root @@ -3846,17 +4076,21 @@ static int cgroup_has_css_refs(struct cgroup *cgrp) for (i = 0; i < CGROUP_SUBSYS_COUNT; i++) { struct cgroup_subsys *ss = subsys[i]; struct cgroup_subsys_state *css; + /* Skip subsystems not present or not in this hierarchy */ if (ss == NULL || ss->root != cgrp->root) continue; + css = cgrp->subsys[ss->subsys_id]; - /* When called from check_for_release() it's possible + /* + * When called from check_for_release() it's possible * that by this point the cgroup has been removed * and the css deleted. But a false-positive doesn't * matter, since it can only happen if the cgroup * has been deleted and hence no longer needs the - * release agent to be called anyway. */ - if (css && (atomic_read(&css->refcnt) > 1)) + * release agent to be called anyway. + */ + if (css && css_refcnt(css) > 1) return 1; } return 0; @@ -3866,51 +4100,63 @@ static int cgroup_has_css_refs(struct cgroup *cgrp) * Atomically mark all (or else none) of the cgroup's CSS objects as * CSS_REMOVED. Return true on success, or false if the cgroup has * busy subsystems. C |