diff options
Diffstat (limited to 'kernel')
48 files changed, 1474 insertions, 865 deletions
diff --git a/kernel/Makefile b/kernel/Makefile index e9cf191..2d64cfc 100644 --- a/kernel/Makefile +++ b/kernel/Makefile @@ -61,7 +61,6 @@ obj-$(CONFIG_COMPAT) += compat.o obj-$(CONFIG_CGROUPS) += cgroup.o obj-$(CONFIG_CGROUP_FREEZER) += cgroup_freezer.o obj-$(CONFIG_CPUSETS) += cpuset.o -obj-$(CONFIG_CGROUP_NS) += ns_cgroup.o obj-$(CONFIG_UTS_NS) += utsname.o obj-$(CONFIG_USER_NS) += user_namespace.o obj-$(CONFIG_PID_NS) += pid_namespace.o diff --git a/kernel/capability.c b/kernel/capability.c index 32a80e0..283c529 100644 --- a/kernel/capability.c +++ b/kernel/capability.c @@ -22,12 +22,8 @@ */ const kernel_cap_t __cap_empty_set = CAP_EMPTY_SET; -const kernel_cap_t __cap_full_set = CAP_FULL_SET; -const kernel_cap_t __cap_init_eff_set = CAP_INIT_EFF_SET; EXPORT_SYMBOL(__cap_empty_set); -EXPORT_SYMBOL(__cap_full_set); -EXPORT_SYMBOL(__cap_init_eff_set); int file_caps_enabled = 1; diff --git a/kernel/cgroup.c b/kernel/cgroup.c index 909a355..2731d11 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -57,6 +57,7 @@ #include <linux/vmalloc.h> /* TODO: replace with more sophisticated array */ #include <linux/eventfd.h> #include <linux/poll.h> +#include <linux/flex_array.h> /* used in cgroup_attach_proc */ #include <asm/atomic.h> @@ -1735,6 +1736,76 @@ int cgroup_path(const struct cgroup *cgrp, char *buf, int buflen) } EXPORT_SYMBOL_GPL(cgroup_path); +/* + * cgroup_task_migrate - move a task from one cgroup to another. + * + * 'guarantee' is set if the caller promises that a new css_set for the task + * will already exist. If not set, this function might sleep, and can fail with + * -ENOMEM. Otherwise, it can only fail with -ESRCH. + */ +static int cgroup_task_migrate(struct cgroup *cgrp, struct cgroup *oldcgrp, + struct task_struct *tsk, bool guarantee) +{ + struct css_set *oldcg; + struct css_set *newcg; + + /* + * get old css_set. we need to take task_lock and refcount it, because + * an exiting task can change its css_set to init_css_set and drop its + * old one without taking cgroup_mutex. + */ + task_lock(tsk); + oldcg = tsk->cgroups; + get_css_set(oldcg); + task_unlock(tsk); + + /* locate or allocate a new css_set for this task. */ + if (guarantee) { + /* we know the css_set we want already exists. */ + struct cgroup_subsys_state *template[CGROUP_SUBSYS_COUNT]; + read_lock(&css_set_lock); + newcg = find_existing_css_set(oldcg, cgrp, template); + BUG_ON(!newcg); + get_css_set(newcg); + read_unlock(&css_set_lock); + } else { + might_sleep(); + /* find_css_set will give us newcg already referenced. */ + newcg = find_css_set(oldcg, cgrp); + if (!newcg) { + put_css_set(oldcg); + return -ENOMEM; + } + } + put_css_set(oldcg); + + /* if PF_EXITING is set, the tsk->cgroups pointer is no longer safe. */ + task_lock(tsk); + if (tsk->flags & PF_EXITING) { + task_unlock(tsk); + put_css_set(newcg); + return -ESRCH; + } + rcu_assign_pointer(tsk->cgroups, newcg); + task_unlock(tsk); + + /* Update the css_set linked lists if we're using them */ + write_lock(&css_set_lock); + if (!list_empty(&tsk->cg_list)) + list_move(&tsk->cg_list, &newcg->tasks); + write_unlock(&css_set_lock); + + /* + * We just gained a reference on oldcg by taking it from the task. As + * trading it for newcg is protected by cgroup_mutex, we're safe to drop + * it here; it will be freed under RCU. + */ + put_css_set(oldcg); + + set_bit(CGRP_RELEASABLE, &oldcgrp->flags); + return 0; +} + /** * cgroup_attach_task - attach task 'tsk' to cgroup 'cgrp' * @cgrp: the cgroup the task is attaching to @@ -1745,11 +1816,9 @@ EXPORT_SYMBOL_GPL(cgroup_path); */ int cgroup_attach_task(struct cgroup *cgrp, struct task_struct *tsk) { - int retval = 0; + int retval; struct cgroup_subsys *ss, *failed_ss = NULL; struct cgroup *oldcgrp; - struct css_set *cg; - struct css_set *newcg; struct cgroupfs_root *root = cgrp->root; /* Nothing to do if the task is already in that cgroup */ @@ -1759,7 +1828,7 @@ int cgroup_attach_task(struct cgroup *cgrp, struct task_struct *tsk) for_each_subsys(root, ss) { if (ss->can_attach) { - retval = ss->can_attach(ss, cgrp, tsk, false); + retval = ss->can_attach(ss, cgrp, tsk); if (retval) { /* * Remember on which subsystem the can_attach() @@ -1771,46 +1840,29 @@ int cgroup_attach_task(struct cgroup *cgrp, struct task_struct *tsk) goto out; } } + if (ss->can_attach_task) { + retval = ss->can_attach_task(cgrp, tsk); + if (retval) { + failed_ss = ss; + goto out; + } + } } - task_lock(tsk); - cg = tsk->cgroups; - get_css_set(cg); - task_unlock(tsk); - /* - * Locate or allocate a new css_set for this task, - * based on its final set of cgroups - */ - newcg = find_css_set(cg, cgrp); - put_css_set(cg); - if (!newcg) { - retval = -ENOMEM; - goto out; - } - - task_lock(tsk); - if (tsk->flags & PF_EXITING) { - task_unlock(tsk); - put_css_set(newcg); - retval = -ESRCH; + retval = cgroup_task_migrate(cgrp, oldcgrp, tsk, false); + if (retval) goto out; - } - rcu_assign_pointer(tsk->cgroups, newcg); - task_unlock(tsk); - - /* Update the css_set linked lists if we're using them */ - write_lock(&css_set_lock); - if (!list_empty(&tsk->cg_list)) - list_move(&tsk->cg_list, &newcg->tasks); - write_unlock(&css_set_lock); for_each_subsys(root, ss) { + if (ss->pre_attach) + ss->pre_attach(cgrp); + if (ss->attach_task) + ss->attach_task(cgrp, tsk); if (ss->attach) - ss->attach(ss, cgrp, oldcgrp, tsk, false); + ss->attach(ss, cgrp, oldcgrp, tsk); } - set_bit(CGRP_RELEASABLE, &oldcgrp->flags); + synchronize_rcu(); - put_css_set(cg); /* * wake up rmdir() waiter. the rmdir should fail since the cgroup @@ -1829,7 +1881,7 @@ out: */ break; if (ss->cancel_attach) - ss->cancel_attach(ss, cgrp, tsk, false); + ss->cancel_attach(ss, cgrp, tsk); } } return retval; @@ -1860,49 +1912,370 @@ int cgroup_attach_task_all(struct task_struct *from, struct task_struct *tsk) EXPORT_SYMBOL_GPL(cgroup_attach_task_all); /* - * Attach task with pid 'pid' to cgroup 'cgrp'. Call with cgroup_mutex - * held. May take task_lock of task + * cgroup_attach_proc works in two stages, the first of which prefetches all + * new css_sets needed (to make sure we have enough memory before committing + * to the move) and stores them in a list of entries of the following type. + * TODO: possible optimization: use css_set->rcu_head for chaining instead + */ +struct cg_list_entry { + struct css_set *cg; + struct list_head links; +}; + +static bool css_set_check_fetched(struct cgroup *cgrp, + struct task_struct *tsk, struct css_set *cg, + struct list_head *newcg_list) +{ + struct css_set *newcg; + struct cg_list_entry *cg_entry; + struct cgroup_subsys_state *template[CGROUP_SUBSYS_COUNT]; + + read_lock(&css_set_lock); + newcg = find_existing_css_set(cg, cgrp, template); + if (newcg) + get_css_set(newcg); + read_unlock(&css_set_lock); + + /* doesn't exist at all? */ + if (!newcg) + return false; + /* see if it's already in the list */ + list_for_each_entry(cg_entry, newcg_list, links) { + if (cg_entry->cg == newcg) { + put_css_set(newcg); + return true; + } + } + + /* not found */ + put_css_set(newcg); + return false; +} + +/* + * Find the new css_set and store it in the list in preparation for moving the + * given task to the given cgroup. Returns 0 or -ENOMEM. + */ +static int css_set_prefetch(struct cgroup *cgrp, struct css_set *cg, + struct list_head *newcg_list) +{ + struct css_set *newcg; + struct cg_list_entry *cg_entry; + + /* ensure a new css_set will exist for this thread */ + newcg = find_css_set(cg, cgrp); + if (!newcg) + return -ENOMEM; + /* add it to the list */ + cg_entry = kmalloc(sizeof(struct cg_list_entry), GFP_KERNEL); + if (!cg_entry) { + put_css_set(newcg); + return -ENOMEM; + } + cg_entry->cg = newcg; + list_add(&cg_entry->links, newcg_list); + return 0; +} + +/** + * cgroup_attach_proc - attach all threads in a threadgroup to a cgroup + * @cgrp: the cgroup to attach to + * @leader: the threadgroup leader task_struct of the group to be attached + * + * Call holding cgroup_mutex and the threadgroup_fork_lock of the leader. Will + * take task_lock of each thread in leader's threadgroup individually in turn. + */ +int cgroup_attach_proc(struct cgroup *cgrp, struct task_struct *leader) +{ + int retval, i, group_size; + struct cgroup_subsys *ss, *failed_ss = NULL; + bool cancel_failed_ss = false; + /* guaranteed to be initialized later, but the compiler needs this */ + struct cgroup *oldcgrp = NULL; + struct css_set *oldcg; + struct cgroupfs_root *root = cgrp->root; + /* threadgroup list cursor and array */ + struct task_struct *tsk; + struct flex_array *group; + /* + * we need to make sure we have css_sets for all the tasks we're + * going to move -before- we actually start moving them, so that in + * case we get an ENOMEM we can bail out before making any changes. + */ + struct list_head newcg_list; + struct cg_list_entry *cg_entry, *temp_nobe; + + /* + * step 0: in order to do expensive, possibly blocking operations for + * every thread, we cannot iterate the thread group list, since it needs + * rcu or tasklist locked. instead, build an array of all threads in the + * group - threadgroup_fork_lock prevents new threads from appearing, + * and if threads exit, this will just be an over-estimate. + */ + group_size = get_nr_threads(leader); + /* flex_array supports very large thread-groups better than kmalloc. */ + group = flex_array_alloc(sizeof(struct task_struct *), group_size, + GFP_KERNEL); + if (!group) + return -ENOMEM; + /* pre-allocate to guarantee space while iterating in rcu read-side. */ + retval = flex_array_prealloc(group, 0, group_size - 1, GFP_KERNEL); + if (retval) + goto out_free_group_list; + + /* prevent changes to the threadgroup list while we take a snapshot. */ + rcu_read_lock(); + if (!thread_group_leader(leader)) { + /* + * a race with de_thread from another thread's exec() may strip + * us of our leadership, making while_each_thread unsafe to use + * on this task. if this happens, there is no choice but to + * throw this task away and try again (from cgroup_procs_write); + * this is "double-double-toil-and-trouble-check locking". + */ + rcu_read_unlock(); + retval = -EAGAIN; + goto out_free_group_list; + } + /* take a reference on each task in the group to go in the array. */ + tsk = leader; + i = 0; + do { + /* as per above, nr_threads may decrease, but not increase. */ + BUG_ON(i >= group_size); + get_task_struct(tsk); + /* + * saying GFP_ATOMIC has no effect here because we did prealloc + * earlier, but it's good form to communicate our expectations. + */ + retval = flex_array_put_ptr(group, i, tsk, GFP_ATOMIC); + BUG_ON(retval != 0); + i++; + } while_each_thread(leader, tsk); + /* remember the number of threads in the array for later. */ + group_size = i; + rcu_read_unlock(); + + /* + * step 1: check that we can legitimately attach to the cgroup. + */ + for_each_subsys(root, ss) { + if (ss->can_attach) { + retval = ss->can_attach(ss, cgrp, leader); + if (retval) { + failed_ss = ss; + goto out_cancel_attach; + } + } + /* a callback to be run on every thread in the threadgroup. */ + if (ss->can_attach_task) { + /* run on each task in the threadgroup. */ + for (i = 0; i < group_size; i++) { + tsk = flex_array_get_ptr(group, i); + retval = ss->can_attach_task(cgrp, tsk); + if (retval) { + failed_ss = ss; + cancel_failed_ss = true; + goto out_cancel_attach; + } + } + } + } + + /* + * step 2: make sure css_sets exist for all threads to be migrated. + * we use find_css_set, which allocates a new one if necessary. + */ + INIT_LIST_HEAD(&newcg_list); + for (i = 0; i < group_size; i++) { + tsk = flex_array_get_ptr(group, i); + /* nothing to do if this task is already in the cgroup */ + oldcgrp = task_cgroup_from_root(tsk, root); + if (cgrp == oldcgrp) + continue; + /* get old css_set pointer */ + task_lock(tsk); + if (tsk->flags & PF_EXITING) { + /* ignore this task if it's going away */ + task_unlock(tsk); + continue; + } + oldcg = tsk->cgroups; + get_css_set(oldcg); + task_unlock(tsk); + /* see if the new one for us is already in the list? */ + if (css_set_check_fetched(cgrp, tsk, oldcg, &newcg_list)) { + /* was already there, nothing to do. */ + put_css_set(oldcg); + } else { + /* we don't already have it. get new one. */ + retval = css_set_prefetch(cgrp, oldcg, &newcg_list); + put_css_set(oldcg); + if (retval) + goto out_list_teardown; + } + } + + /* + * step 3: now that we're guaranteed success wrt the css_sets, proceed + * to move all tasks to the new cgroup, calling ss->attach_task for each + * one along the way. there are no failure cases after here, so this is + * the commit point. + */ + for_each_subsys(root, ss) { + if (ss->pre_attach) + ss->pre_attach(cgrp); + } + for (i = 0; i < group_size; i++) { + tsk = flex_array_get_ptr(group, i); + /* leave current thread as it is if it's already there */ + oldcgrp = task_cgroup_from_root(tsk, root); + if (cgrp == oldcgrp) + continue; + /* attach each task to each subsystem */ + for_each_subsys(root, ss) { + if (ss->attach_task) + ss->attach_task(cgrp, tsk); + } + /* if the thread is PF_EXITING, it can just get skipped. */ + retval = cgroup_task_migrate(cgrp, oldcgrp, tsk, true); + BUG_ON(retval != 0 && retval != -ESRCH); + } + /* nothing is sensitive to fork() after this point. */ + + /* + * step 4: do expensive, non-thread-specific subsystem callbacks. + * TODO: if ever a subsystem needs to know the oldcgrp for each task + * being moved, this call will need to be reworked to communicate that. + */ + for_each_subsys(root, ss) { + if (ss->attach) + ss->attach(ss, cgrp, oldcgrp, leader); + } + + /* + * step 5: success! and cleanup + */ + synchronize_rcu(); + cgroup_wakeup_rmdir_waiter(cgrp); + retval = 0; +out_list_teardown: + /* clean up the list of prefetched css_sets. */ + list_for_each_entry_safe(cg_entry, temp_nobe, &newcg_list, links) { + list_del(&cg_entry->links); + put_css_set(cg_entry->cg); + kfree(cg_entry); + } +out_cancel_attach: + /* same deal as in cgroup_attach_task */ + if (retval) { + for_each_subsys(root, ss) { + if (ss == failed_ss) { + if (cancel_failed_ss && ss->cancel_attach) + ss->cancel_attach(ss, cgrp, leader); + break; + } + if (ss->cancel_attach) + ss->cancel_attach(ss, cgrp, leader); + } + } + /* clean up the array of referenced threads in the group. */ + for (i = 0; i < group_size; i++) { + tsk = flex_array_get_ptr(group, i); + put_task_struct(tsk); + } +out_free_group_list: + flex_array_free(group); + return retval; +} + +/* + * Find the task_struct of the task to attach by vpid and pass it along to the + * function to attach either it or all tasks in its threadgroup. Will take + * cgroup_mutex; may take task_lock of task. */ -static int attach_task_by_pid(struct cgroup *cgrp, u64 pid) +static int attach_task_by_pid(struct cgroup *cgrp, u64 pid, bool threadgroup) { struct task_struct *tsk; const struct cred *cred = current_cred(), *tcred; int ret; + if (!cgroup_lock_live_group(cgrp)) + return -ENODEV; + if (pid) { rcu_read_lock(); tsk = find_task_by_vpid(pid); - if (!tsk || tsk->flags & PF_EXITING) { + if (!tsk) { rcu_read_unlock(); + cgroup_unlock(); + return -ESRCH; + } + if (threadgroup) { + /* + * RCU protects this access, since tsk was found in the + * tid map. a race with de_thread may cause group_leader + * to stop being the leader, but cgroup_attach_proc will + * detect it later. + */ + tsk = tsk->group_leader; + } else if (tsk->flags & PF_EXITING) { + /* optimization for the single-task-only case */ + rcu_read_unlock(); + cgroup_unlock(); return -ESRCH; } + /* + * even if we're attaching all tasks in the thread group, we + * only need to check permissions on one of them. + */ tcred = __task_cred(tsk); if (cred->euid && cred->euid != tcred->uid && cred->euid != tcred->suid) { rcu_read_unlock(); + cgroup_unlock(); return -EACCES; } get_task_struct(tsk); rcu_read_unlock(); } else { - tsk = current; + if (threadgroup) + tsk = current->group_leader; + else + tsk = current; get_task_struct(tsk); } - ret = cgroup_attach_task(cgrp, tsk); + if (threadgroup) { + threadgroup_fork_write_lock(tsk); + ret = cgroup_attach_proc(cgrp, tsk); + threadgroup_fork_write_unlock(tsk); + } else { + ret = cgroup_attach_task(cgrp, tsk); + } put_task_struct(tsk); + cgroup_unlock(); return ret; } static int cgroup_tasks_write(struct cgroup *cgrp, struct cftype *cft, u64 pid) { + return attach_task_by_pid(cgrp, pid, false); +} + +static int cgroup_procs_write(struct cgroup *cgrp, struct cftype *cft, u64 tgid) +{ int ret; - if (!cgroup_lock_live_group(cgrp)) - return -ENODEV; - ret = attach_task_by_pid(cgrp, pid); - cgroup_unlock(); + do { + /* + * attach_proc fails with -EAGAIN if threadgroup leadership + * changes in the middle of the operation, in which case we need + * to find the task_struct for the new leader and start over. + */ + ret = attach_task_by_pid(cgrp, tgid, true); + } while (ret == -EAGAIN); return ret; } @@ -3259,9 +3632,9 @@ static struct cftype files[] = { { .name = CGROUP_FILE_GENERIC_PREFIX "procs", .open = cgroup_procs_open, - /* .write_u64 = cgroup_procs_write, TODO */ + .write_u64 = cgroup_procs_write, .release = cgroup_pidlist_release, - .mode = S_IRUGO, + .mode = S_IRUGO | S_IWUSR, }, { .name = "notify_on_release", @@ -4257,122 +4630,6 @@ void cgroup_exit(struct task_struct *tsk, int run_callbacks) } /** - * cgroup_clone - clone the cgroup the given subsystem is attached to - * @tsk: the task to be moved - * @subsys: the given subsystem - * @nodename: the name for the new cgroup - * - * Duplicate the current cgroup in the hierarchy that the given - * subsystem is attached to, and move this task into the new - * child. - */ -int cgroup_clone(struct task_struct *tsk, struct cgroup_subsys *subsys, - char *nodename) -{ - struct dentry *dentry; - int ret = 0; - struct cgroup *parent, *child; - struct inode *inode; - struct css_set *cg; - struct cgroupfs_root *root; - struct cgroup_subsys *ss; - - /* We shouldn't be called by an unregistered subsystem */ - BUG_ON(!subsys->active); - - /* First figure out what hierarchy and cgroup we're dealing - * with, and pin them so we can drop cgroup_mutex */ - mutex_lock(&cgroup_mutex); - again: - root = subsys->root; - if (root == &rootnode) { - mutex_unlock(&cgroup_mutex); - return 0; - } - - /* Pin the hierarchy */ - if (!atomic_inc_not_zero(&root->sb->s_active)) { - /* We race with the final deactivate_super() */ - mutex_unlock(&cgroup_mutex); - return 0; - } - - /* Keep the cgroup alive */ - task_lock(tsk); - parent = task_cgroup(tsk, subsys->subsys_id); - cg = tsk->cgroups; - get_css_set(cg); - task_unlock(tsk); - - mutex_unlock(&cgroup_mutex); - - /* Now do the VFS work to create a cgroup */ - inode = parent->dentry->d_inode; - - /* Hold the parent directory mutex across this operation to - * stop anyone else deleting the new cgroup */ - mutex_lock(&inode->i_mutex); - dentry = lookup_one_len(nodename, parent->dentry, strlen(nodename)); - if (IS_ERR(dentry)) { - printk(KERN_INFO - "cgroup: Couldn't allocate dentry for %s: %ld\n", nodename, - PTR_ERR(dentry)); - ret = PTR_ERR(dentry); - goto out_release; - } - - /* Create the cgroup directory, which also creates the cgroup */ - ret = vfs_mkdir(inode, dentry, 0755); - child = __d_cgrp(dentry); - dput(dentry); - if (ret) { - printk(KERN_INFO - "Failed to create cgroup %s: %d\n", nodename, - ret); - goto out_release; - } - - /* The cgroup now exists. Retake cgroup_mutex and check - * that we're still in the same state that we thought we - * were. */ - mutex_lock(&cgroup_mutex); - if ((root != subsys->root) || - (parent != task_cgroup(tsk, subsys->subsys_id))) { - /* Aargh, we raced ... */ - mutex_unlock(&inode->i_mutex); - put_css_set(cg); - - deactivate_super(root->sb); - /* The cgroup is still accessible in the VFS, but - * we're not going to try to rmdir() it at this - * point. */ - printk(KERN_INFO - "Race in cgroup_clone() - leaking cgroup %s\n", - nodename); - goto again; - } - - /* do any required auto-setup */ - for_each_subsys(root, ss) { - if (ss->post_clone) - ss->post_clone(ss, child); - } - - /* All seems fine. Finish by moving the task into the new cgroup */ - ret = cgroup_attach_task(child, tsk); - mutex_unlock(&cgroup_mutex); - - out_release: - mutex_unlock(&inode->i_mutex); - - mutex_lock(&cgroup_mutex); - put_css_set(cg); - mutex_unlock(&cgroup_mutex); - deactivate_super(root->sb); - return ret; -} - -/** * cgroup_is_descendant - see if @cgrp is a descendant of @task's cgrp * @cgrp: the cgroup in question * @task: the task in question diff --git a/kernel/cgroup_freezer.c b/kernel/cgroup_freezer.c index e7bebb7..e691818 100644 --- a/kernel/cgroup_freezer.c +++ b/kernel/cgroup_freezer.c @@ -160,7 +160,7 @@ static void freezer_destroy(struct cgroup_subsys *ss, */ static int freezer_can_attach(struct cgroup_subsys *ss, struct cgroup *new_cgroup, - struct task_struct *task, bool threadgroup) + struct task_struct *task) { struct freezer *freezer; @@ -172,26 +172,17 @@ static int freezer_can_attach(struct cgroup_subsys *ss, if (freezer->state != CGROUP_THAWED) return -EBUSY; + return 0; +} + +static int freezer_can_attach_task(struct cgroup *cgrp, struct task_struct *tsk) +{ rcu_read_lock(); - if (__cgroup_freezing_or_frozen(task)) { + if (__cgroup_freezing_or_frozen(tsk)) { rcu_read_unlock(); return -EBUSY; } rcu_read_unlock(); - - if (threadgroup) { - struct task_struct *c; - - rcu_read_lock(); - list_for_each_entry_rcu(c, &task->thread_group, thread_group) { - if (__cgroup_freezing_or_frozen(c)) { - rcu_read_unlock(); - return -EBUSY; - } - } - rcu_read_unlock(); - } - return 0; } @@ -390,6 +381,9 @@ struct cgroup_subsys freezer_subsys = { .populate = freezer_populate, .subsys_id = freezer_subsys_id, .can_attach = freezer_can_attach, + .can_attach_task = freezer_can_attach_task, + .pre_attach = NULL, + .attach_task = NULL, .attach = NULL, .fork = freezer_fork, .exit = NULL, diff --git a/kernel/compat.c b/kernel/compat.c index 9214dcd..fc9eb093 100644 --- a/kernel/compat.c +++ b/kernel/compat.c @@ -293,6 +293,8 @@ asmlinkage long compat_sys_times(struct compat_tms __user *tbuf) return compat_jiffies_to_clock_t(jiffies); } +#ifdef __ARCH_WANT_SYS_SIGPENDING + /* * Assumption: old_sigset_t and compat_old_sigset_t are both * types that can be passed to put_user()/get_user(). @@ -312,6 +314,10 @@ asmlinkage long compat_sys_sigpending(compat_old_sigset_t __user *set) return ret; } +#endif + +#ifdef __ARCH_WANT_SYS_SIGPROCMASK + asmlinkage long compat_sys_sigprocmask(int how, compat_old_sigset_t __user *set, compat_old_sigset_t __user *oset) { @@ -333,6 +339,8 @@ asmlinkage long compat_sys_sigprocmask(int how, compat_old_sigset_t __user *set, return ret; } +#endif + asmlinkage long compat_sys_setrlimit(unsigned int resource, struct compat_rlimit __user *rlim) { diff --git a/kernel/cpuset.c b/kernel/cpuset.c index 2bb8c2e..9c9b754 100644 --- a/kernel/cpuset.c +++ b/kernel/cpuset.c @@ -1367,14 +1367,10 @@ static int fmeter_getrate(struct fmeter *fmp) return val; } -/* Protected by cgroup_lock */ -static cpumask_var_t cpus_attach; - /* Called by cgroups to determine if a cpuset is usable; cgroup_mutex held */ static int cpuset_can_attach(struct cgroup_subsys *ss, struct cgroup *cont, - struct task_struct *tsk, bool threadgroup) + struct task_struct *tsk) { - int ret; struct cpuset *cs = cgroup_cs(cont); if (cpumask_empty(cs->cpus_allowed) || nodes_empty(cs->mems_allowed)) @@ -1391,29 +1387,42 @@ static int cpuset_can_attach(struct cgroup_subsys *ss, struct cgroup *cont, if (tsk->flags & PF_THREAD_BOUND) return -EINVAL; - ret = security_task_setscheduler(tsk); - if (ret) - return ret; - if (threadgroup) { - struct task_struct *c; - - rcu_read_lock(); - list_for_each_entry_rcu(c, &tsk->thread_group, thread_group) { - ret = security_task_setscheduler(c); - if (ret) { - rcu_read_unlock(); - return ret; - } - } - rcu_read_unlock(); - } return 0; } -static void cpuset_attach_task(struct task_struct *tsk, nodemask_t *to, - struct cpuset *cs) +static int cpuset_can_attach_task(struct cgroup *cgrp, struct task_struct *task) +{ + return security_task_setscheduler(task); +} + +/* + * Protected by cgroup_lock. The nodemasks must be stored globally because + * dynamically allocating them is not allowed in pre_attach, and they must + * persist among pre_attach, attach_task, and attach. + */ +static cpumask_var_t cpus_attach; +static nodemask_t cpuset_attach_nodemask_from; +static nodemask_t cpuset_attach_nodemask_to; + +/* Set-up work for before attaching each task. */ +static void cpuset_pre_attach(struct cgroup *cont) +{ + struct cpuset *cs = cgroup_cs(cont); + + if (cs == &top_cpuset) + cpumask_copy(cpus_attach, cpu_possible_mask); + else + guarantee_online_cpus(cs, cpus_attach); + + guarantee_online_mems(cs, &cpuset_attach_nodemask_to); +} + +/* Per-thread attachment work. */ +static void cpuset_attach_task(struct cgroup *cont, struct task_struct *tsk) { int err; + struct cpuset *cs = cgroup_cs(cont); + /* * can_attach beforehand should guarantee that this doesn't fail. * TODO: have a better way to handle failure here @@ -1421,45 +1430,29 @@ static void cpuset_attach_task(struct task_struct *tsk, nodemask_t *to, err = set_cpus_allowed_ptr(tsk, cpus_attach); WARN_ON_ONCE(err); - cpuset_change_task_nodemask(tsk, to); + cpuset_change_task_nodemask(tsk, &cpuset_attach_nodemask_to); cpuset_update_task_spread_flag(cs, tsk); - } static void cpuset_attach(struct cgroup_subsys *ss, struct cgroup *cont, - struct cgroup *oldcont, struct task_struct *tsk, - bool threadgroup) + struct cgroup *oldcont, struct task_struct *tsk) { struct mm_struct *mm; struct cpuset *cs = cgroup_cs(cont); struct cpuset *oldcs = cgroup_cs(oldcont); - static nodemask_t to; /* protected by cgroup_mutex */ - if (cs == &top_cpuset) { - cpumask_copy(cpus_attach, cpu_possible_mask); - } else { - guarantee_online_cpus(cs, cpus_attach); - } - guarantee_online_mems(cs, &to); - - /* do per-task migration stuff possibly for each in the threadgroup */ - cpuset_attach_task(tsk, &to, cs); - if (threadgroup) { - struct task_struct *c; - rcu_read_lock(); - list_for_each_entry_rcu(c, &tsk->thread_group, thread_group) { - cpuset_attach_task(c, &to, cs); - } - rcu_read_unlock(); - } - - /* change mm; only needs to be done once even if threadgroup */ - to = cs->mems_allowed; + /* + * Change mm, possibly for multiple threads in a threadgroup. This is + * expensive and may sleep. + */ + cpuset_attach_nodemask_from = oldcs->mems_allowed; + cpuset_attach_nodemask_to = cs->mems_allowed; mm = get_task_mm(tsk); if (mm) { - mpol_rebind_mm(mm, &to); + mpol_rebind_mm(mm, &cpuset_attach_nodemask_to); if (is_memory_migrate(cs)) - cpuset_migrate_mm(mm, &oldcs->mems_allowed, &to); + cpuset_migrate_mm(mm, &cpuset_attach_nodemask_from, + &cpuset_attach_nodemask_to); mmput(mm); } } @@ -1809,10 +1802,9 @@ static int cpuset_populate(struct cgroup_subsys *ss, struct cgroup *cont) } /* - * post_clone() is called at the end of cgroup_clone(). - * 'cgroup' was just created automatically as a result of - * a cgroup_clone(), and the current task is about to - * be moved into 'cgroup'. + * post_clone() is called during cgroup_create() when the + * clone_children mount argument was specified. The cgroup + * can not yet have any tasks. * * Currently we refuse to set up the cgroup - thereby * refusing the task to be entered, and as a result refusing @@ -1911,6 +1903,9 @@ struct cgroup_subsys cpuset_subsys = { .create = cpuset_create, .destroy = cpuset_destroy, .can_attach = cpuset_can_attach, + .can_attach_task = cpuset_can_attach_task, + .pre_attach = cpuset_pre_attach, + .attach_task = cpuset_attach_task, .attach = cpuset_attach, .populate = cpuset_populate, .post_clone = cpuset_post_clone, @@ -2195,7 +2190,7 @@ int cpuset_cpus_allowed_fallback(struct task_struct *tsk) rcu_read_lock(); cs = task_cs(tsk); if (cs) - cpumask_copy(&tsk->cpus_allowed, cs->cpus_allowed); + do_set_cpus_allowed(tsk, cs->cpus_allowed); rcu_read_unlock(); /* @@ -2222,7 +2217,7 @@ int cpuset_cpus_allowed_fallback(struct task_struct *tsk) * Like above we can temporary set any mask and rely on * set_cpus_allowed_ptr() as synchronization point. */ - cpumask_copy(&tsk->cpus_allowed, cpu_possible_mask); + do_set_cpus_allowed(tsk, cpu_possible_mask); cpu = cpumask_any(cpu_active_mask); } diff --git a/kernel/cred.c b/kernel/cred.c index 8093c16..174fa84 100644 --- a/kernel/cred.c +++ b/kernel/cred.c @@ -1,4 +1,4 @@ -/* Task credentials management - see Documentation/credentials.txt +/* Task credentials management - see Documentation/security/credentials.txt * * Copyright (C) 2008 Red Hat, Inc. All Rights Reserved. * Written by David Howells (dhowells@redhat.com) @@ -49,10 +49,10 @@ struct cred init_cred = { .magic = CRED_MAGIC, #endif .securebits = SECUREBITS_DEFAULT, - .cap_inheritable = CAP_INIT_INH_SET, + .cap_inheritable = CAP_EMPTY_SET, .cap_permitted = CAP_FULL_SET, - .cap_effective = CAP_INIT_EFF_SET, - .cap_bset = CAP_INIT_BSET, + .cap_effective = CAP_FULL_SET, + .cap_bset = CAP_FULL_SET, .user = INIT_USER, .user_ns = &init_user_ns, .group_info = &init_groups, diff --git a/kernel/events/core.c b/kernel/events/core.c index c09767f..9efe710 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -5028,6 +5028,14 @@ static int __perf_event_overflow(struct perf_event *event, int nmi, else perf_event_output(event, nmi, data, regs); + if (event->fasync && event->pending_kill) { + if (nmi) { + event->pending_wakeup = 1; + irq_work_queue(&event->pending); + } else + perf_event_wakeup(event); + } + return ret; } @@ -7394,26 +7402,12 @@ static int __perf_cgroup_move(void *info) return 0; } -static void perf_cgroup_move(struct task_struct *task) +static void +perf_cgroup_attach_task(struct cgroup *cgrp, struct task_struct *task) { task_function_call(task, __perf_cgroup_move, task); } -static void perf_cgroup_attach(struct cgroup_subsys *ss, struct cgroup *cgrp, - struct cgroup *old_cgrp, struct task_struct *task, - bool threadgroup) -{ - perf_cgroup_move(task); - if (threadgroup) { - struct task_struct *c; - rcu_read_lock(); - list_for_each_entry_rcu(c, &task->thread_group, thread_group) { - perf_cgroup_move(c); - } - rcu_read_unlock(); - } -} - static void perf_cgroup_exit(struct cgroup_subsys *ss, struct cgroup *cgrp, struct cgroup *old_cgrp, struct task_struct *task) { @@ -7425,7 +7419,7 @@ static void perf_cgroup_exit(struct cgroup_subsys *ss, struct cgroup *cgrp, if (!(task->flags & PF_EXITING)) return; - perf_cgroup_move(task); + perf_cgroup_attach_task(cgrp, task); } struct cgroup_subsys perf_subsys = { @@ -7434,6 +7428,6 @@ struct cgroup_subsys perf_subsys = { .create = perf_cgroup_create, .destroy = perf_cgroup_destroy, .exit = perf_cgroup_exit, - .attach = perf_cgroup_attach, + .attach_task = perf_cgroup_attach_task, }; #endif /* CONFIG_CGROUP_PERF */ diff --git a/kernel/fork.c b/kernel/fork.c index 2b44d82..0276c30 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -59,7 +59,6 @@ #include <linux/taskstats_kern.h> #include <linux/random.h> #include <linux/tty.h> -#include <linux/proc_fs.h> #include <linux/blkdev.h> #include <linux/fs_struct.h> #include <linux/magic.h> @@ -383,15 +382,14 @@ static int dup_mmap(struct mm_struct *mm, struct mm_struct *oldmm) get_file(file); if (tmp->vm_flags & VM_DENYWRITE) atomic_dec(&inode->i_writecount); - spin_lock(&mapping->i_mmap_lock); + mutex_lock(&mapping->i_mmap_mutex); if (tmp->vm_flags & VM_SHARED) mapping->i_mmap_writable++; - tmp->vm_truncate_count = mpnt->vm_truncate_count; flush_dcache_mmap_lock(mapping); /* insert tmp into the share list, just after mpnt */ vma_prio_tree_add(tmp, mpnt); flush_dcache_mmap_unlock(mapping); - spin_unlock(&mapping->i_mmap_lock); + mutex_unlock(&mapping->i_mmap_mutex); } /* @@ -522,11 +520,12 @@ struct mm_struct * mm_alloc(void) struct mm_struct * mm; mm = allocate_mm(); - if (mm) { - memset(mm, 0, sizeof(*mm)); - mm = mm_init(mm, current); - } - return mm; + if (!mm) + return NULL; + + memset(mm, 0, sizeof(*mm)); + mm_init_cpumask(mm); + return mm_init(mm, current); } /* @@ -573,6 +572,57 @@ void mmput(struct mm_struct *mm) } EXPORT_SYMBOL_GPL(mmput); +/* + * We added or removed a vma mapping the executable. The vmas are only mapped + * during exec and are not mapped with the mmap system call. + * Callers must hold down_write() on the mm's mmap_sem for these + */ +void added_exe_file_vma(struct mm_struct *mm) +{ + mm->num_exe_file_vmas++; +} + +void removed_exe_file_vma(struct mm_struct *mm) +{ + mm->num_exe_file_vmas--; + if ((mm->num_exe_file_vmas == 0) && mm->exe_file){ + fput(mm->exe_file); + mm->exe_file = NULL; + } + +} + +void set_mm_exe_file(struct mm_struct *mm, struct file *new_exe_file) +{ + if (new_exe_file) + get_file(new_exe_file); + if (mm->exe_file) + fput(mm->exe_file); + mm->exe_file = new_exe_file; + mm->num_exe_file_vmas = 0; +} + +struct file *get_mm_exe_file(struct mm_struct *mm) +{ + struct file *exe_file; + + /* We need mmap_sem to protect against races with removal of + * VM_EXECUTABLE vmas */ + down_read(&mm->mmap_sem); + exe_file = mm->exe_file; + if (exe_file) + get_file(exe_file); + up_read(&mm->mmap_sem); + return exe_file; +} + +static void dup_mm_exe_file(struct mm_struct *oldmm, struct mm_struct *newmm) +{ + /* It's safe to write the exe_file pointer without exe_file_lock because + * this is called during fork when the task is not yet in /proc */ + newmm->exe_file = get_mm_exe_file(oldmm); +} + /** * get_task_mm - acquire a reference to the task's mm * @@ -679,6 +729,7 @@ struct mm_struct *dup_mm(struct task_struct *tsk) goto fail_nomem; memcpy(mm, oldmm, sizeof(*mm)); + mm_init_cpumask(mm); /* Initializing for Swap token stuff */ mm->token_priority = 0; @@ -927,6 +978,10 @@ static int copy_signal(unsigned long clone_flags, struct task_struct *tsk) tty_audit_fork(sig); sched_autogroup_fork(sig); +#ifdef CONFIG_CGROUPS + init_rwsem(&sig->threadgroup_fork_lock); +#endif + sig->oom_adj = current->signal->oom_adj; sig->oom_score_adj = current->signal->oom_score_adj; sig->oom_score_adj_min = current->signal->oom_score_adj_min; @@ -1108,6 +1163,8 @@ static struct task_struct *copy_process(unsigned long clone_flags, monotonic_to_bootbased(&p->real_start_time); p->io_context = NULL; p->audit_context = NULL; + if (clone_flags & CLONE_THREAD) + threadgroup_fork_read_lock(current); cgroup_fork(p); #ifdef CONFIG_NUMA p->mempolicy = mpol_dup(p->mempolicy); @@ -1193,12 +1250,6 @@ static struct task_struct *copy_process(unsigned long clone_flags, if (clone_flags & CLONE_THREAD) p->tgid = current->tgid; - if (current->nsproxy != p->nsproxy) { - retval = ns_cgroup_clone(p, pid); - if (retval) - goto bad_fork_free_pid; - } - p->set_child_tid = (clone_flags & CLONE_CHILD_SETTID) ? child_tidptr : NULL; /* * Clear TID on mm_release()? @@ -1312,6 +1363,8 @@ static struct task_struct *copy_process(unsigned long clone_flags, write_unlock_irq(&tasklist_lock); proc_fork_connector(p); cgroup_post_fork(p); + if (clone_flags & CLONE_THREAD) + threadgroup_fork_read_unlock(current); perf_event_fork(p); return p; @@ -1350,6 +1403,8 @@ bad_fork_cleanup_policy: mpol_put(p->mempolicy); bad_fork_cleanup_cgroup: #endif + if (clone_flags & CLONE_THREAD) + threadgroup_fork_read_unlock(current); cgroup_exit(p, cgroup_callbacks_done); delayacct_tsk_free(p); module_put(task_thread_info(p)->exec_domain->module); @@ -1507,6 +1562,13 @@ void __init proc_caches_init(void) fs_cachep = kmem_cache_create("fs_cache", sizeof(struct fs_struct), 0, SLAB_HWCACHE_ALIGN|SLAB_PANIC|SLAB_NOTRACK, NULL); + /* + * FIXME! The "sizeof(struct mm_struct)" currently includes the + * whole struct cpumask for the OFFSTACK case. We could change + * this to *only* allocate as much of it as required by the + * maximum number of CPU's we can ever have. The cpumask_allocation + * is at the end of the structure, exactly for that reason. + */ mm_cachep = kmem_cache_create("mm_struct", sizeof(struct mm_struct), ARCH_MIN_MMSTRUCT_ALIGN, SLAB_HWCACHE_ALIGN|SLAB_PANIC|SLAB_NOTRACK, NULL); diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c index c541ee5..a9205e3 100644 --- a/kernel/hrtimer.c +++ b/kernel/hrtimer.c @@ -748,7 +748,7 @@ static inline void retrigger_next_event(void *arg) { } */ void clock_was_set(void) { -#ifdef CONFIG_HIGHRES_TIMERS +#ifdef CONFIG_HIGH_RES_TIMERS /* Retrigger the CPU local events everywhere */ on_each_cpu(retrigger_next_event, NULL, 1); #endif diff --git a/kernel/irq/handle.c b/kernel/irq/handle.c index 90cb55f..470d08c 100644 --- a/kernel/irq/handle.c +++ b/kernel/irq/handle.c @@ -133,12 +133,6 @@ handle_irq_event_percpu(struct irq_desc *desc, struct irqaction *action) switch (res) { case IRQ_WAKE_THREAD: /* - * Set result to handled so the spurious check - * does not trigger. - */ - res = IRQ_HANDLED; - - /* * Catch drivers which return WAKE_THREAD but * did not set up a thread function */ diff --git a/kernel/irq/irqdesc.c b/kernel/irq/irqdesc.c index 886e803..4c60a50 100644 --- a/kernel/irq/irqdesc.c +++ b/kernel/irq/irqdesc.c @@ -257,13 +257,11 @@ int __init early_irq_init(void) count = ARRAY_SIZE(irq_desc); for (i = 0; i < count; i++) { - desc[i].irq_data.irq = i; - desc[i].irq_data.chip = &no_irq_chip; desc[i].kstat_irqs = alloc_percpu(unsigned int); - irq_settings_clr_and_set(desc, ~0, _IRQ_DEFAULT_INIT_FLAGS); - alloc_masks(desc + i, GFP_KERNEL, node); - desc_smp_init(desc + i, node); + alloc_masks(&desc[i], GFP_KERNEL, node); + raw_spin_lock_init(&desc[i].lock); lockdep_set_class(&desc[i].lock, &irq_desc_lock_class); + desc_set_defaults(i, &desc[i], node); } return arch_early_irq_init(); } @@ -346,6 +344,12 @@ irq_alloc_descs(int irq, unsigned int from, unsigned int cnt, int node) if (!cnt) return -EINVAL; + if (irq >= 0) { + if (from > irq) + return -EINVAL; + from = irq; + } + mutex_lock(&sparse_irq_lock); start = bitmap_find_next_zero_area(allocated_irqs, IRQ_BITMAP_BITS, diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c index f7ce002..d64bafb 100644 --- a/kernel/irq/manage.c +++ b/kernel/irq/manage.c @@ -723,13 +723,16 @@ irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action) { } * context. So we need to disable bh here to avoid deadlocks and other * side effects. */ -static void +static irqreturn_t irq_forced_thread_fn(struct irq_desc *desc, struct irqaction *action) { + irqreturn_t ret; + local_bh_disable(); - action->thread_fn(action->irq, action->dev_id); + ret = action->thread_fn(action->irq, action->dev_id); irq_finalize_oneshot(desc, action, false); local_bh_enable(); + return ret; } /* @@ -737,10 +740,14 @@ irq_forced_thread_fn(struct irq_desc *desc, struct irqaction *action) * preemtible - many of them need to sleep and wait for slow busses to * complete. */ -static void irq_thread_fn(struct irq_desc *desc, struct irqaction *action) +static irqreturn_t irq_thread_fn(struct irq_desc *desc, + struct irqaction *action) { - action->thread_fn(action->irq, action->dev_id); + irqreturn_t ret; + + ret = action->thread_fn(action->irq, action->dev_id); irq_finalize_oneshot(desc, action, false); + return ret; } /* @@ -753,7 +760,8 @@ static int irq_thread(void *data) }; struct irqaction *action = data; struct irq_desc *desc = irq_to_desc(action->irq); - void (*handler_fn)(struct irq_desc *desc, struct irqaction *action); + irqreturn_t (*handler_fn)(struct irq_desc *desc, + struct irqaction *action); int wake; if (force_irqthreads & test_bit(IRQTF_FORCED_THREAD, @@ -783,8 +791,12 @@ static int irq_thread(void *data) desc->istate |= IRQS_PENDING; raw_spin_unlock_irq(&desc->lock); } else { + irqreturn_t action_ret; + raw_spin_unlock_irq(&desc->lock); - handler_fn(desc, action); + action_ret = handler_fn(desc, action); + if (!noirqdebug) + note_interrupt(action->irq, desc, action_ret); } wake = atomic_dec_and_test(&desc->threads_active); diff --git a/kernel/irq/proc.c b/kernel/irq/proc.c index 834899f..4bd4faa 100644 --- a/kernel/irq/proc.c +++ b/kernel/irq/proc.c @@ -19,7 +19,7 @@ static struct proc_dir_entry *root_irq_dir; #ifdef CONFIG_SMP -static int irq_affinity_proc_show(struct seq_file *m, void *v) +static int show_irq_affinity(int type, struct seq_file *m, void *v) { struct irq_desc *desc = irq_to_desc((long)m->private); const struct cpumask *mask = desc->irq_data.affinity; @@ -28,7 +28,10 @@ static int irq_affinity_proc_show(struct seq_file *m, void *v) if (irqd_is_setaffinity_pending(&desc->irq_data)) mask = desc->pending_mask; #endif - seq_cpumask(m, mask); + if (type) + seq_cpumask_list(m, mask); + else + seq_cpumask(m, mask); seq_putc(m, '\n'); return 0; } @@ -59,7 +62,18 @@ static int irq_affinity_hint_proc_show(struct seq_file *m, void *v) #endif int no_irq_affinity; -static ssize_t irq_affinity_proc_write(struct file *file, +static int irq_affinity_proc_show(struct seq_file *m, void *v) +{ + return show_irq_affinity(0, m, v); +} + +static int irq_affinity_list_proc_show(struct seq_file *m, void *v) +{ + return show_irq_affinity(1, m, v); +} + + +static ssize_t write_irq_affinity(int type, struct file *file, const char __user *buffer, size_t count, loff_t *pos) { unsigned int irq = (int)(long)PDE(file->f_path.dentry->d_inode)->data; @@ -72,7 +86,10 @@ static ssize_t irq_affinity_proc_write(struct file *file, if (!alloc_cpumask_var(&new_value, GFP_KERNEL)) return -ENOMEM; - err = cpumask_parse_user(buffer, count, new_value); + if (type) + err = cpumask_parselist_user(buffer, count, new_value); + else + err = cpumask_parse_user(buffer, count, new_value); if (err) goto free_cpumask; @@ -100,11 +117,28 @@ free_cpumask: return err; } +static ssize_t irq_affinity_proc_write(struct file *file, + const char __user *buffer, size_t count, loff_t *pos) +{ + return write_irq_affinity(0, file, buffer, count, pos); +} + +static ssize_t irq_affinity_list_proc_write(struct file *file, + const char __user *buffer, size_t count, loff_t *pos) +{ + return write_irq_affinity(1, file, buffer, count, pos); +} + static int irq_affinity_proc_open(struct inode *inode, struct file *file) { return single_open(file, irq_affinity_proc_show, PDE(inode)->data); } +static int irq_affinity_list_proc_open(struct inode *inode, struct file *file) +{ + return single_open(file, irq_affinity_list_proc_show, PDE(inode)->data); +} + static int irq_affinity_hint_proc_open(struct inode *inode, struct file *file) { return single_open(file, irq_affinity_hint_proc_show, PDE(inode)->data); @@ -125,6 +159,14 @@ static const struct file_operations irq_affinity_hint_proc_fops = { .release = single_release, }; +static const struct file_operations irq_affinity_list_proc_fops = { + .open = irq_affinity_list_proc_open, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, + .write = irq_affinity_list_proc_write, +}; + static int default_affinity_show(struct seq_file *m, void *v) { seq_cpumask(m, irq_default_affinity); @@ -289,6 +331,10 @@ void register_irq_proc(unsigned int irq, struct irq_desc *desc) proc_create_data("affinity_hint", 0400, desc->dir, &irq_affinity_hint_proc_fops, (void *)(long)irq); + /* create /proc/irq/<irq>/smp_affinity_list */ + proc_create_data("smp_affinity_list", 0600, desc->dir, + &irq_affinity_list_proc_fops, (void *)(long)irq); + proc_create_data("node", 0444, desc->dir, &irq_node_proc_fops, (void *)(long)irq); #endif @@ -306,6 +352,7 @@ void unregister_irq_proc(unsigned int irq, struct irq_desc *desc) #ifdef CONFIG_SMP remove_proc_entry("smp_affinity", desc->dir); remove_proc_entry("affinity_hint", desc->dir); + remove_proc_entry("smp_affinity_list", desc->dir); remove_proc_entry("node", desc->dir); #endif remove_proc_entry("spurious", desc->dir); diff --git a/kernel/irq/spurious.c b/kernel/irq/spurious.c index dfbd550..aa57d5d 100644 --- a/kernel/irq/spurious.c +++ b/kernel/irq/spurious.c @@ -167,6 +167,13 @@ out: jiffies + POLL_SPURIOUS_IRQ_INTERVAL); } +static inline int bad_action_ret(irqreturn_t action_ret) +{ + if (likely(action_ret <= (IRQ_HANDLED | IRQ_WAKE_THREAD))) + return 0; + return 1; +} + /* * If 99,900 of the previous 100,000 interrupts have not been handled * then assume that the IRQ is stuck in some manner. Drop a diagnostic @@ -182,7 +189,7 @@ __report_bad_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *action; unsigned long flags; - if (action_ret != IRQ_HANDLED && action_ret != IRQ_NONE) { + if (bad_action_ret(action_ret)) { printk(KERN_ERR "irq event %d: bogus return value %x\n", irq, action_ret); } else { @@ -201,10 +208,11 @@ __report_bad_irq(unsigned int irq, struct irq_desc *desc, raw_spin_lock_irqsave(&desc->lock, flags); action = desc->action; while (action) { - printk(KERN_ERR "[<%p>]", action->handler); - print_symbol(" (%s)", - (unsigned long)action->handler); - printk("\n"); + printk(KERN_ERR "[<%p>] %pf", action->handler, action->handler); + if (action->thread_fn) + printk(KERN_CONT " threaded [<%p>] %pf", + action->thread_fn, action->thread_fn); + printk(KERN_CONT "\n"); action = action->next; } raw_spin_unlock_irqrestore(&desc->lock, flags); @@ -262,7 +270,16 @@ void note_interrupt(unsigned int irq, struct irq_desc *desc, if (desc->istate & IRQS_POLL_INPROGRESS) return; - if (unlikely(action_ret != IRQ_HANDLED)) { + /* we get here again via the threaded handler */ + if (action_ret == IRQ_WAKE_THREAD) + return; + + if (bad_action_ret(action_ret)) { + report_bad_irq(irq, desc, action_ret); + return; + } + + if (unlikely(action_ret == IRQ_NONE)) { /* * If we are seeing only the odd spurious IRQ caused by * bus asynchronicity then don't eventually trigger an error, @@ -274,8 +291,6 @@ void note_interrupt(unsigned int irq, struct irq_desc *desc, else desc->irqs_unhandled++; desc->last_unhandled = jiffies; - if (unlikely(action_ret != IRQ_NONE)) - report_bad_irq(irq, desc, action_ret); } if (unlikely(try_misrouted_irq(irq, desc, action_ret))) { diff --git a/kernel/jump_label.c b/kernel/jump_label.c index 74d1c09..fa27e75 100644 --- a/kernel/jump_label.c +++ b/kernel/jump_label.c @@ -105,9 +105,12 @@ static int __jump_label_text_reserved(struct jump_entry *iter_start, } static void __jump_label_update(struct jump_label_key *key, - struct jump_entry *entry, int enable) + struct jump_entry *entry, + struct jump_entry *stop, int enable) { - for (; entry->key == (jump_label_t)(unsigned long)key; entry++) { + for (; (entry < stop) && + (entry->key == (jump_label_t)(unsigned long)key); + entry++) { /* * entry->code set to 0 invalidates module init text sections * kernel_text_address() verifies we are not in core kernel @@ -181,7 +184,11 @@ static void __jump_label_mod_update(struct jump_label_key *key, int enable) struct jump_label_mod *mod = key->next; while (mod) { - __jump_label_update(key, mod->entries, enable); + struct module *m = mod->mod; + + __jump_label_update(key, mod->entries, + m->jump_entries + m->num_jump_entries, + enable); mod = mod->next; } } @@ -245,7 +252,8 @@ static int jump_label_add_module(struct module *mod) key->next = jlm; if (jump_label_enabled(key)) - __jump_label_update(key, iter, JUMP_LABEL_ENABLE); + __jump_label_update(key, iter, iter_stop, + JUMP_LABEL_ENABLE); } return 0; @@ -371,7 +379,7 @@ static void jump_label_update(struct jump_label_key *key, int enable) /* if there are no users, entry can be NULL */ if (entry) - __jump_label_update(key, entry, enable); + __jump_label_update(key, entry, __stop___jump_table, enable); #ifdef CONFIG_MODULES __jump_label_mod_update(key, enable); diff --git a/kernel/kmod.c b/kernel/kmod.c index 5ae0ff3..ad6a81c 100644 --- a/kernel/kmod.c +++ b/kernel/kmod.c @@ -25,6 +25,7 @@ #include <linux/kmod.h> #include <linux/slab.h> #include <linux/completion.h> +#include <linux/cred.h> #include <linux/file.h> #include <linux/fdtable.h> #include <linux/workqueue.h> @@ -43,6 +44,13 @@ extern int max_threads; static struct workqueue_struct *khelper_wq; +#define CAP_BSET (void *)1 +#define CAP_PI (void *)2 + +static kernel_cap_t usermodehelper_bset = CAP_FULL_SET; +static kernel_cap_t usermodehelper_inheritable = CAP_FULL_SET; +static DEFINE_SPINLOCK(umh_sysctl_lock); + #ifdef CONFIG_MODULES /* @@ -132,6 +140,7 @@ EXPORT_SYMBOL(__request_module); static int ____call_usermodehelper(void *data) { struct subprocess_info *sub_info = data; + struct cred *new; int retval; spin_lock_irq(¤t->sighand->siglock); @@ -153,6 +162,19 @@ static int ____call_usermodehelper(void *data) goto fail; } + retval = -ENOMEM; + new = prepare_kernel_cred(current); + if (!new) + goto fail; + + spin_lock(&umh_sysctl_lock); + new->cap_bset = cap_intersect(usermodehelper_bset, new->cap_bset); + new->cap_inheritable = cap_intersect(usermodehelper_inheritable, + new->cap_inheritable); + spin_unlock(&umh_sysctl_lock); + + commit_creds(new); + retval = kernel_execve(sub_info->path, (const char *const *)sub_info->argv, (const char *const *)sub_info->envp); @@ -420,6 +442,84 @@ unlock: } EXPORT_SYMBOL(call_usermodehelper_exec); +static int proc_cap_handler(struct ctl_table *table, int write, + void __user *buffer, size_t *lenp, loff_t *ppos) +{ + struct ctl_table t; + unsigned long cap_array[_KERNEL_CAPABILITY_U32S]; + kernel_cap_t new_cap; + int err, i; + + if (write && (!capable(CAP_SETPCAP) || + !capable(CAP_SYS_MODULE))) + return -EPERM; + + /* + * convert from the global kernel_cap_t to the ulong array to print to + * userspace if this is a read. + */ + spin_lock(&umh_sysctl_lock); + for (i = 0; i < _KERNEL_CAPABILITY_U32S; i++) { + if (table->data == CAP_BSET) + cap_array[i] = usermodehelper_bset.cap[i]; + else if (table->data == CAP_PI) + cap_array[i] = usermodehelper_inheritable.cap[i]; + else + BUG(); + } + spin_unlock(&umh_sysctl_lock); + + t = *table; + t.data = &cap_array; + + /* + * actually read or write and array of ulongs from userspace. Remember + * these are least significant 32 bits first + */ + err = proc_doulongvec_minmax(&t, write, buffer, lenp, ppos); + if (err < 0) + return err; + + /* + * convert from the sysctl array of ulongs to the kernel_cap_t + * internal representation + */ + for (i = 0; i < _KERNEL_CAPABILITY_U32S; i++) + new_cap.cap[i] = cap_array[i]; + + /* + * Drop everything not in the new_cap (but don't add things) + */ + spin_lock(&umh_sysctl_lock); + if (write) { + if (table->data == CAP_BSET) + usermodehelper_bset = cap_intersect(usermodehelper_bset, new_cap); + if (table->data == CAP_PI) + usermodehelper_inheritable = cap_intersect(usermodehelper_inheritable, new_cap); + } + spin_unlock(&umh_sysctl_lock); + + return 0; +} + +struct ctl_table usermodehelper_table[] = { + { + .procname = "bset", + .data = CAP_BSET, + .maxlen = _KERNEL_CAPABILITY_U32S * sizeof(unsigned long), + .mode = 0600, + .proc_handler = proc_cap_handler, + }, + { + .procname = "inheritable", + .data = CAP_PI, + .maxlen = _KERNEL_CAPABILITY_U32S * sizeof(unsigned long), + .mode = 0600, + .proc_handler = proc_cap_handler, + }, + { } +}; + void __init usermodehelper_init(void) { khelper_wq = create_singlethread_workqueue("khelper"); diff --git a/kernel/kthread.c b/kernel/kthread.c index 3b34d27..4ba7ccc 100644 --- a/kernel/kthread.c +++ b/kernel/kthread.c @@ -202,8 +202,8 @@ void kthread_bind(struct task_struct *p, unsigned int cpu) return; } - p->cpus_allowed = cpumask_of_cpu(cpu); - p->rt.nr_cpus_allowed = 1; + /* It's safe because the task is inactive. */ + do_set_cpus_allowed(p, cpumask_of(cpu)); p->flags |= PF_THREAD_BOUND; } EXPORT_SYMBOL(kthread_bind); diff --git a/kernel/lockdep.c b/kernel/lockdep.c index 63437d0..298c927 100644 --- a/kernel/lockdep.c +++ b/kernel/lockdep.c @@ -3426,7 +3426,7 @@ int lock_is_held(struct lockdep_map *lock) int ret = 0; if (unlikely(current->lockdep_recursion)) - return ret; + return 1; /* avoid false negative lockdep_assert_held() */ raw_local_irq_save(flags); check_flags(flags); diff --git a/kernel/mutex.c b/kernel/mutex.c index 2c938e2..d607ed5 100644 --- a/kernel/mutex.c +++ b/kernel/mutex.c @@ -131,14 +131,14 @@ EXPORT_SYMBOL(mutex_unlock); */ static inline int __sched __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass, - unsigned long ip) + struct lockdep_map *nest_lock, unsigned long ip) { struct task_struct *task = current; struct mutex_waiter waiter; unsigned long flags; preempt_disable(); - mutex_acquire(&lock->dep_map, subclass, 0, ip); + mutex_acquire_nest(&lock->dep_map, subclass, 0, nest_lock, ip); #ifdef CONFIG_MUTEX_SPIN_ON_OWNER /* @@ -269,16 +269,25 @@ void __sched mutex_lock_nested(struct mutex *lock, unsigned int subclass) { might_sleep(); - __mutex_lock_common(lock, TASK_UNINTERRUPTIBLE, subclass, _RET_IP_); + __mutex_lock_common(lock, TASK_UNINTERRUPTIBLE, subclass, NULL, _RET_IP_); } EXPORT_SYMBOL_GPL(mutex_lock_nested); +void __sched +_mutex_lock_nest_lock(struct mutex *lock, struct lockdep_map *nest) +{ + might_sleep(); + __mutex_lock_common(lock, TASK_UNINTERRUPTIBLE, 0, nest, _RET_IP_); +} + +EXPORT_SYMBOL_GPL(_mutex_lock_nest_lock); + int __sched mutex_lock_killable_nested(struct mutex *lock, unsigned int subclass) { might_sleep(); - return __mutex_lock_common(lock, TASK_KILLABLE, subclass, _RET_IP_); + return __mutex_lock_common(lock, TASK_KILLABLE, subclass, NULL, _RET_IP_); } EXPORT_SYMBOL_GPL(mutex_lock_killable_nested); @@ -287,7 +296,7 @@ mutex_lock_interruptible_nested(struct mutex *lock, unsigned int subclass) { might_sleep(); return __mutex_lock_common(lock, TASK_INTERRUPTIBLE, - subclass, _RET_IP_); + subclass, NULL, _RET_IP_); } EXPORT_SYMBOL_GPL(mutex_lock_interruptible_nested); @@ -393,7 +402,7 @@ __mutex_lock_slowpath(atomic_t *lock_count) { struct mutex *lock = container_of(lock_count, struct mutex, count); - __mutex_lock_common(lock, TASK_UNINTERRUPTIBLE, 0, _RET_IP_); + __mutex_lock_common(lock, TASK_UNINTERRUPTIBLE, 0, NULL, _RET_IP_); } static noinline int __sched @@ -401,7 +410,7 @@ __mutex_lock_killable_slowpath(atomic_t *lock_count) { struct mutex *lock = container_of(lock_count, struct mutex, count); - return __mutex_lock_common(lock, TASK_KILLABLE, 0, _RET_IP_); + return __mutex_lock_common(lock, TASK_KILLABLE, 0, NULL, _RET_IP_); } static noinline int __sched @@ -409,7 +418,7 @@ __mutex_lock_interruptible_slowpath(atomic_t *lock_count) { struct mutex *lock = container_of(lock_count, struct mutex, count); - return __mutex_lock_common(lock, TASK_INTERRUPTIBLE, 0, _RET_IP_); + return __mutex_lock_common(lock, TASK_INTERRUPTIBLE, 0, NULL, _RET_IP_); } #endif diff --git a/kernel/ns_cgroup.c b/kernel/ns_cgroup.c deleted file mode 100644 index 2c98ad9..0000000 --- a/kernel/ns_cgroup.c +++ /dev/null @@ -1,118 +0,0 @@ -/* - * ns_cgroup.c - namespace cgroup subsystem - * - * Copyright 2006, 2007 IBM Corp - */ - -#include <linux/module.h> -#include <linux/cgroup.h> -#include <linux/fs.h> -#include <linux/proc_fs.h> -#include <linux/slab.h> -#include <linux/nsproxy.h> - -struct ns_cgroup { - struct cgroup_subsys_state css; -}; - -struct cgroup_subsys ns_subsys; - -static inline struct ns_cgroup *cgroup_to_ns( - struct cgroup *cgroup) -{ - return container_of(cgroup_subsys_state(cgroup, ns_subsys_id), - struct ns_cgroup, css); -} - -int ns_cgroup_clone(struct task_struct *task, struct pid *pid) -{ - char name[PROC_NUMBUF]; - - snprintf(name, PROC_NUMBUF, "%d", pid_vnr(pid)); - return cgroup_clone(task, &ns_subsys, name); -} - -/* - * Rules: - * 1. you can only enter a cgroup which is a descendant of your current - * cgroup - * 2. you can only place another process into a cgroup if - * a. you have CAP_SYS_ADMIN - * b. your cgroup is an ancestor of task's destination cgroup - * (hence either you are in the same cgroup as task, or in an - * ancestor cgroup thereof) - */ -static int ns_can_attach(struct cgroup_subsys *ss, struct cgroup *new_cgroup, - struct task_struct *task, bool threadgroup) -{ - if (current != task) { - if (!capable(CAP_SYS_ADMIN)) - return -EPERM; - - if (!cgroup_is_descendant(new_cgroup, current)) - return -EPERM; - } - - if (!cgroup_is_descendant(new_cgroup, task)) - return -EPERM; - - if (threadgroup) { - struct task_struct *c; - rcu_read_lock(); - list_for_each_entry_rcu(c, &task->thread_group, thread_group) { - if (!cgroup_is_descendant(new_cgroup, c)) { - rcu_read_unlock(); - return -EPERM; - } - } - rcu_read_unlock(); - } - - return 0; -} - -/* - * Rules: you can only create a cgroup if - * 1. you are capable(CAP_SYS_ADMIN) - * 2. the target cgroup is a descendant of your own cgroup - */ -static struct cgroup_subsys_state *ns_create(struct cgroup_subsys *ss, - struct cgroup *cgroup) -{ - struct ns_cgroup *ns_cgroup; - - if (!capable(CAP_SYS_ADMIN)) - return ERR_PTR(-EPERM); - if (!cgroup_is_descendant(cgroup, current)) - return ERR_PTR(-EPERM); - if (test_bit(CGRP_CLONE_CHILDREN, &cgroup->flags)) { - printk("ns_cgroup can't be created with parent " - "'clone_children' set.\n"); - return ERR_PTR(-EINVAL); - } - - printk_once("ns_cgroup deprecated: consider using the " - "'clone_children' flag without the ns_cgroup.\n"); - - ns_cgroup = kzalloc(sizeof(*ns_cgroup), GFP_KERNEL); - if (!ns_cgroup) - return ERR_PTR(-ENOMEM); - return &ns_cgroup->css; -} - -static void ns_destroy(struct cgroup_subsys *ss, - struct cgroup *cgroup) -{ - struct ns_cgroup *ns_cgroup; - - ns_cgroup = cgroup_to_ns(cgroup); - kfree(ns_cgroup); -} - -struct cgroup_subsys ns_subsys = { - .name = "ns", - .can_attach = ns_can_attach, - .create = ns_create, - .destroy = ns_destroy, - .subsys_id = ns_subsys_id, -}; diff --git a/kernel/nsproxy.c b/kernel/nsproxy.c index a05d191..d6a00f3 100644 --- a/kernel/nsproxy.c +++ b/kernel/nsproxy.c @@ -22,6 +22,9 @@ #include <linux/pid_namespace.h> #include <net/net_namespace.h> #include <linux/ipc_namespace.h> +#include <linux/proc_fs.h> +#include <linux/file.h> +#include <linux/syscalls.h> static struct kmem_cache *nsproxy_cachep; @@ -198,10 +201,6 @@ int unshare_nsproxy_namespaces(unsigned long unshare_flags, goto out; } - err = ns_cgroup_clone(current, task_pid(current)); - if (err) - put_nsproxy(*new_nsp); - out: return err; } @@ -233,6 +232,45 @@ void exit_task_namespaces(struct task_struct *p) switch_task_namespaces(p, NULL); } +SYSCALL_DEFINE2(setns, int, fd, int, nstype) +{ + const struct proc_ns_operations *ops; + struct task_struct *tsk = current; + struct nsproxy *new_nsproxy; + struct proc_inode *ei; + struct file *file; + int err; + + if (!capable(CAP_SYS_ADMIN)) + return -EPERM; + + file = proc_ns_fget(fd); + if (IS_ERR(file)) + return PTR_ERR(file); + + err = -EINVAL; + ei = PROC_I(file->f_dentry->d_inode); + ops = ei->ns_ops; + if (nstype && (ops->type != nstype)) + goto out; + + new_nsproxy = create_new_namespaces(0, tsk, tsk->fs); + if (IS_ERR(new_nsproxy)) { + err = PTR_ERR(new_nsproxy); + goto out; + } + + err = ops->install(new_nsproxy, ei->ns); + if (err) { + free_nsproxy(new_nsproxy); + goto out; + } + switch_task_namespaces(tsk, new_nsproxy); +out: + fput(file); + return err; +} + static int __init nsproxy_cache_init(void) { nsproxy_cachep = KMEM_CACHE(nsproxy, SLAB_PANIC); diff --git a/kernel/pm_qos_params.c b/kernel/pm_qos_params.c index beb1846..6824ca7 100644 --- a/kernel/pm_qos_params.c +++ b/kernel/pm_qos_params.c @@ -40,6 +40,7 @@ #include <linux/string.h> #include <linux/platform_device.h> #include <linux/init.h> +#include <linux/kernel.h> #include <linux/uaccess.h> @@ -53,11 +54,17 @@ enum pm_qos_type { PM_QOS_MIN /* return the smallest value */ }; +/* + * Note: The lockless read path depends on the CPU accessing + * target_value atomically. Atomic access is only guaranteed on all CPU + * types linux supports for 32 bit quantites + */ struct pm_qos_object { struct plist_head requests; struct blocking_notifier_head *notifiers; struct miscdevice pm_qos_power_miscdev; char *name; + s32 target_value; /* Do not change to 64 bit */ s32 default_value; enum pm_qos_type type; }; @@ -70,7 +77,8 @@ static struct pm_qos_object cpu_dma_pm_qos = { .requests = PLIST_HEAD_INIT(cpu_dma_pm_qos.requests, pm_qos_lock), .notifiers = &cpu_dma_lat_notifier, .name = "cpu_dma_latency", - .default_value = 2000 * USEC_PER_SEC, + .target_value = PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE, + .default_value = PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE, .type = PM_QOS_MIN, }; @@ -79,7 +87,8 @@ static struct pm_qos_object network_lat_pm_qos = { .requests = PLIST_HEAD_INIT(network_lat_pm_qos.requests, pm_qos_lock), .notifiers = &network_lat_notifier, .name = "network_latency", - .default_value = 2000 * USEC_PER_SEC, + .target_value = PM_QOS_NETWORK_LAT_DEFAULT_VALUE, + .default_value = PM_QOS_NETWORK_LAT_DEFAULT_VALUE, .type = PM_QOS_MIN }; @@ -89,7 +98,8 @@ static struct pm_qos_object network_throughput_pm_qos = { .requests = PLIST_HEAD_INIT(network_throughput_pm_qos.requests, pm_qos_lock), .notifiers = &network_throughput_notifier, .name = "network_throughput", - .default_value = 0, + .target_value = PM_QOS_NETWORK_THROUGHPUT_DEFAULT_VALUE, + .default_value = PM_QOS_NETWORK_THROUGHPUT_DEFAULT_VALUE, .type = PM_QOS_MAX, }; @@ -135,6 +145,16 @@ static inline int pm_qos_get_value(struct pm_qos_object *o) } } +static inline s32 pm_qos_read_value(struct pm_qos_object *o) +{ + return o->target_value; +} + +static inline void pm_qos_set_value(struct pm_qos_object *o, s32 value) +{ + o->target_value = value; +} + static void update_target(struct pm_qos_object *o, struct plist_node *node, int del, int value) { @@ -159,6 +179,7 @@ static void update_target(struct pm_qos_object *o, struct plist_node *node, plist_add(node, &o->requests); } curr_value = pm_qos_get_value(o); + pm_qos_set_value(o, curr_value); spin_unlock_irqrestore(&pm_qos_lock, flags); if (prev_value != curr_value) @@ -193,18 +214,11 @@ static int find_pm_qos_object_by_minor(int minor) * pm_qos_request - returns current system wide qos expectation * @pm_qos_class: identification of which qos value is requested * - * This function returns the current target value in an atomic manner. + * This function returns the current target value. */ int pm_qos_request(int pm_qos_class) { - unsigned long flags; - int value; - - spin_lock_irqsave(&pm_qos_lock, flags); - value = pm_qos_get_value(pm_qos_array[pm_qos_class]); - spin_unlock_irqrestore(&pm_qos_lock, flags); - - return value; + return pm_qos_read_value(pm_qos_array[pm_qos_class]); } EXPORT_SYMBOL_GPL(pm_qos_request); @@ -404,24 +418,36 @@ static ssize_t pm_qos_power_write(struct file *filp, const char __user *buf, size_t count, loff_t *f_pos) { s32 value; - int x; - char ascii_value[11]; struct pm_qos_request_list *pm_qos_req; if (count == sizeof(s32)) { if (copy_from_user(&value, buf, sizeof(s32))) return -EFAULT; - } else if (count == 11) { /* len('0x12345678/0') */ - if (copy_from_user(ascii_value, buf, 11)) + } else if (count <= 11) { /* ASCII perhaps? */ + char ascii_value[11]; + unsigned long int ulval; + int ret; + + if (copy_from_user(ascii_value, buf, count)) return -EFAULT; - if (strlen(ascii_value) != 10) - return -EINVAL; - x = sscanf(ascii_value, "%x", &value); - if (x != 1) + + if (count > 10) { + if (ascii_value[10] == '\n') + ascii_value[10] = '\0'; + else + return -EINVAL; + } else { + ascii_value[count] = '\0'; + } + ret = strict_strtoul(ascii_value, 16, &ulval); + if (ret) { + pr_debug("%s, 0x%lx, 0x%x\n", ascii_value, ulval, ret); return -EINVAL; - pr_debug("%s, %d, 0x%x\n", ascii_value, x, value); - } else + } + value = (s32)lower_32_bits(ulval); + } else { return -EINVAL; + } pm_qos_req = filp->private_data; pm_qos_update_request(pm_qos_req, value); diff --git a/kernel/posix-timers.c b/kernel/posix-timers.c index a1b5edf..4556182 100644 --- a/kernel/posix-timers.c +++ b/kernel/posix-timers.c @@ -491,6 +491,13 @@ static struct k_itimer * alloc_posix_timer(void) return tmr; } +static void k_itimer_rcu_free(struct rcu_head *head) +{ + struct k_itimer *tmr = container_of(head, struct k_itimer, it.rcu); + + kmem_cache_free(posix_timers_cache, tmr); +} + #define IT_ID_SET 1 #define IT_ID_NOT_SET 0 static void release_posix_timer(struct k_itimer *tmr, int it_id_set) @@ -503,7 +510,7 @@ static void release_posix_timer(struct k_itimer *tmr, int it_id_set) } put_pid(tmr->it_pid); sigqueue_free(tmr->sigq); - kmem_cache_free(posix_timers_cache, tmr); + call_rcu(&tmr->it.rcu, k_itimer_rcu_free); } static struct k_clock *clockid_to_kclock(const clockid_t id) @@ -631,22 +638,18 @@ out: static struct k_itimer *__lock_timer(timer_t timer_id, unsigned long *flags) { struct k_itimer *timr; - /* - * Watch out here. We do a irqsave on the idr_lock and pass the - * flags part over to the timer lock. Must not let interrupts in - * while we are moving the lock. - */ - spin_lock_irqsave(&idr_lock, *flags); + + rcu_read_lock(); timr = idr_find(&posix_timers_id, (int)timer_id); if (timr) { - spin_lock(&timr->it_lock); + spin_lock_irqsave(&timr->it_lock, *flags); if (timr->it_signal == current->signal) { - spin_unlock(&idr_lock); + rcu_read_unlock(); return timr; } - spin_unlock(&timr->it_lock); + spin_unlock_irqrestore(&timr->it_lock, *flags); } - spin_unlock_irqrestore(&idr_lock, *flags); + rcu_read_unlock(); return NULL; } diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c index f9bec56..8f7b1db 100644 --- a/kernel/power/hibernate.c +++ b/kernel/power/hibernate.c @@ -25,7 +25,6 @@ #include <linux/gfp.h> #include <linux/syscore_ops.h> #include <scsi/scsi_scan.h> -#include <asm/suspend.h> #include "power.h" @@ -55,10 +54,9 @@ static int hibernation_mode = HIBERNATION_SHUTDOWN; static const struct platform_hibernation_ops *hibernation_ops; /** - * hibernation_set_ops - set the global hibernate operations - * @ops: the hibernation operations to use in subsequent hibernation transitions + * hibernation_set_ops - Set the global hibernate operations. + * @ops: Hibernation operations to use in subsequent hibernation transitions. */ - void hibernation_set_ops(const struct platform_hibernation_ops *ops) { if (ops && !(ops->begin && ops->end && ops->pre_snapshot @@ -115,10 +113,9 @@ static int hibernation_test(int level) { return 0; } #endif /* !CONFIG_PM_DEBUG */ /** - * platform_begin - tell the platform driver that we're starting - * hibernation + * platform_begin - Call platform to start hibernation. + * @platform_mode: Whether or not to use the platform driver. */ - static int platform_begin(int platform_mode) { return (platform_mode && hibernation_ops) ? @@ -126,10 +123,9 @@ static int platform_begin(int platform_mode) } /** - * platform_end - tell the platform driver that we've entered the - * working state + * platform_end - Call platform to finish transition to the working state. + * @platform_mode: Whether or not to use the platform driver. */ - static void platform_end(int platform_mode) { if (platform_mode && hibernation_ops) @@ -137,8 +133,11 @@ static void platform_end(int platform_mode) } /** - * platform_pre_snapshot - prepare the machine for hibernation using the - * platform driver if so configured and return an error code if it fails + * platform_pre_snapshot - Call platform to prepare the machine for hibernation. + * @platform_mode: Whether or not to use the platform driver. + * + * Use the platform driver to prepare the system for creating a hibernate image, + * if so configured, and return an error code if that fails. */ static int platform_pre_snapshot(int platform_mode) @@ -148,10 +147,14 @@ static int platform_pre_snapshot(int platform_mode) } /** - * platform_leave - prepare the machine for switching to the normal mode - * of operation using the platform driver (called with interrupts disabled) + * platform_leave - Call platform to prepare a transition to the working state. + * @platform_mode: Whether or not to use the platform driver. + * + * Use the platform driver prepare to prepare the machine for switching to the + * normal mode of operation. + * + * This routine is called on one CPU with interrupts disabled. */ - static void platform_leave(int platform_mode) { if (platform_mode && hibernation_ops) @@ -159,10 +162,14 @@ static void platform_leave(int platform_mode) } /** - * platform_finish - switch the machine to the normal mode of operation - * using the platform driver (must be called after platform_prepare()) + * platform_finish - Call platform to switch the system to the working state. + * @platform_mode: Whether or not to use the platform driver. + * + * Use the platform driver to switch the machine to the normal mode of + * operation. + * + * This routine must be called after platform_prepare(). */ - static void platform_finish(int platform_mode) { if (platform_mode && hibernation_ops) @@ -170,11 +177,15 @@ static void platform_finish(int platform_mode) } /** - * platform_pre_restore - prepare the platform for the restoration from a - * hibernation image. If the restore fails after this function has been - * called, platform_restore_cleanup() must be called. + * platform_pre_restore - Prepare for hibernate image restoration. + * @platform_mode: Whether or not to use the platform driver. + * + * Use the platform driver to prepare the system for resume from a hibernation + * image. + * + * If the restore fails after this function has been called, + * platform_restore_cleanup() must be called. */ - static int platform_pre_restore(int platform_mode) { return (platform_mode && hibernation_ops) ? @@ -182,12 +193,16 @@ static int platform_pre_restore(int platform_mode) } /** - * platform_restore_cleanup - switch the platform to the normal mode of - * operation after a failing restore. If platform_pre_restore() has been - * called before the failing restore, this function must be called too, - * regardless of the result of platform_pre_restore(). + * platform_restore_cleanup - Switch to the working state after failing restore. + * @platform_mode: Whether or not to use the platform driver. + * + * Use the platform driver to switch the system to the normal mode of operation + * after a failing restore. + * + * If platform_pre_restore() has been called before the failing restore, this + * function must be called too, regardless of the result of + * platform_pre_restore(). */ - static void platform_restore_cleanup(int platform_mode) { if (platform_mode && hibernation_ops) @@ -195,10 +210,9 @@ static void platform_restore_cleanup(int platform_mode) } /** - * platform_recover - recover the platform from a failure to suspend - * devices. + * platform_recover - Recover from a failure to suspend devices. + * @platform_mode: Whether or not to use the platform driver. */ - static void platform_recover(int platform_mode) { if (platform_mode && hibernation_ops && hibernation_ops->recover) @@ -206,13 +220,12 @@ static void platform_recover(int platform_mode) } /** - * swsusp_show_speed - print the time elapsed between two events. - * @start: Starting event. - * @stop: Final event. - * @nr_pages - number of pages processed between @start and @stop - * @msg - introductory message to print + * swsusp_show_speed - Print time elapsed between two events during hibernation. + * @start: Starting event. + * @stop: Final event. + * @nr_pages: Number of memory pages processed between @start and @stop. + * @msg: Additional diagnostic message to print. */ - void swsusp_show_speed(struct timeval *start, struct timeval *stop, unsigned nr_pages, char *msg) { @@ -235,25 +248,18 @@ void swsusp_show_speed(struct timeval *start, struct timeval *stop, } /** - * create_image - freeze devices that need to be frozen with interrupts - * off, create the hibernation image and thaw those devices. Control - * reappears in this routine after a restore. + * create_image - Create a hibernation image. + * @platform_mode: Whether or not to use the platform driver. + * + * Execute device drivers' .freeze_noirq() callbacks, create a hibernation image + * and execute the drivers' .thaw_noirq() callbacks. + * + * Control reappears in this routine after the subsequent restore. */ - static int create_image(int platform_mode) { int error; - error = arch_prepare_suspend(); - if (error) - return error; - - /* At this point, dpm_suspend_start() has been called, but *not* - * dpm_suspend_noirq(). We *must* call dpm_suspend_noirq() now. - * Otherwise, drivers for some devices (e.g. interrupt controllers) - * become desynchronized with the actual state of the hardware - * at resume time, and evil weirdness ensues. - */ error = dpm_suspend_noirq(PMSG_FREEZE); if (error) { printk(KERN_ERR "PM: Some devices failed to power down, " @@ -297,9 +303,6 @@ static int create_image(int platform_mode) Power_up: syscore_resume(); - /* NOTE: dpm_resume_noirq() is just a resume() for devices - * that suspended with irqs off ... no overall powerup. - */ Enable_irqs: local_irq_enable(); @@ -317,14 +320,11 @@ static int create_image(int platform_mode) } /** - * hibernation_snapshot - quiesce devices and create the hibernation - * snapshot image. - * @platform_mode - if set, use the platform driver, if available, to - * prepare the platform firmware for the power transition. + * hibernation_snapshot - Quiesce devices and create a hibernation image. + * @platform_mode: If set, use platform driver to prepare for the transition. * - * Must be called with pm_mutex held + * This routine must be called with pm_mutex held. */ - int hibernation_snapshot(int platform_mode) { pm_message_t msg = PMSG_RECOVER; @@ -384,13 +384,14 @@ int hibernation_snapshot(int platform_mode) } /** - * resume_target_kernel - prepare devices that need to be suspended with - * interrupts off, restore the contents of highmem that have not been - * restored yet from the image and run the low level code that will restore - * the remaining contents of memory and switch to the just restored target - * kernel. + * resume_target_kernel - Restore system state from a hibernation image. + * @platform_mode: Whether or not to use the platform driver. + * + * Execute device drivers' .freeze_noirq() callbacks, restore the contents of + * highmem that have not been restored yet from the image and run the low-level + * code that will restore the remaining contents of memory and switch to the + * just restored target kernel. */ - static int resume_target_kernel(bool platform_mode) { int error; @@ -416,24 +417,26 @@ static int resume_target_kernel(bool platform_mode) if (error) goto Enable_irqs; - /* We'll ignore saved state, but this gets preempt count (etc) right */ save_processor_state(); error = restore_highmem(); if (!error) { error = swsusp_arch_resume(); /* * The code below is only ever reached in case of a failure. - * Otherwise execution continues at place where - * swsusp_arch_suspend() was called + * Otherwise, execution continues at the place where + * swsusp_arch_suspend() was called. */ BUG_ON(!error); - /* This call to restore_highmem() undos the previous one */ + /* + * This call to restore_highmem() reverts the changes made by + * the previous one. + */ restore_highmem(); } /* * The only reason why swsusp_arch_resume() can fail is memory being * very tight, so we have to free it as soon as we can to avoid - * subsequent failures + * subsequent failures. */ swsusp_free(); restore_processor_state(); @@ -456,14 +459,12 @@ static int resume_target_kernel(bool platform_mode) } /** - * hibernation_restore - quiesce devices and restore the hibernation - * snapshot image. If successful, control returns in hibernation_snaphot() - * @platform_mode - if set, use the platform driver, if available, to - * prepare the platform firmware for the transition. + * hibernation_restore - Quiesce devices and restore from a hibernation image. + * @platform_mode: If set, use platform driver to prepare for the transition. * - * Must be called with pm_mutex held + * This routine must be called with pm_mutex held. If it is successful, control + * reappears in the restored target kernel in hibernation_snaphot(). */ - int hibernation_restore(int platform_mode) { int error; @@ -483,10 +484,8 @@ int hibernation_restore(int platform_mode) } /** - * hibernation_platform_enter - enter the hibernation state using the - * platform driver (if available) + * hibernation_platform_enter - Power off the system using the platform driver. */ - int hibernation_platform_enter(void) { int error; @@ -557,12 +556,12 @@ int hibernation_platform_enter(void) } /** - * power_down - Shut the machine down for hibernation. + * power_down - Shut the machine down for hibernation. * - * Use the platform driver, if configured so; otherwise try - * to power off or reboot. + * Use the platform driver, if configured, to put the system into the sleep + * state corresponding to hibernation, or try to power it off or reboot, + * depending on the value of hibernation_mode. */ - static void power_down(void) { switch (hibernation_mode) { @@ -599,9 +598,8 @@ static int prepare_processes(void) } /** - * hibernate - The granpappy of the built-in hibernation management + * hibernate - Carry out system hibernation, including saving the image. */ - int hibernate(void) { int error; @@ -679,17 +677,20 @@ int hibernate(void) /** - * software_resume - Resume from a saved image. + * software_resume - Resume from a saved hibernation image. * - * Called as a late_initcall (so all devices are discovered and - * initialized), we call swsusp to see if we have a saved image or not. - * If so, we quiesce devices, the restore the saved image. We will - * return above (in hibernate() ) if everything goes well. - * Otherwise, we fail gracefully and return to the normally - * scheduled program. + * This routine is called as a late initcall, when all devices have been + * discovered and initialized already. * + * The image reading code is called to see if there is a hibernation image + * available for reading. If that is the case, devices are quiesced and the + * contents of memory is restored from the saved image. + * + * If this is successful, control reappears in the restored target kernel in + * hibernation_snaphot() which returns to hibernate(). Otherwise, the routine + * attempts to recover gracefully and make the kernel return to the normal mode + * of operation. */ - static int software_resume(void) { int error; @@ -819,21 +820,17 @@ static const char * const hibernation_modes[] = { [HIBERNATION_TESTPROC] = "testproc", }; -/** - * disk - Control hibernation mode - * - * Suspend-to-disk can be handled in several ways. We have a few options - * for putting the system to sleep - using the platform driver (e.g. ACPI - * or other hibernation_ops), powering off the system or rebooting the - * system (for testing) as well as the two test modes. +/* + * /sys/power/disk - Control hibernation mode. * - * The system can support 'platform', and that is known a priori (and - * encoded by the presence of hibernation_ops). However, the user may - * choose 'shutdown' or 'reboot' as alternatives, as well as one fo the - * test modes, 'test' or 'testproc'. + * Hibernation can be handled in several ways. There are a few different ways + * to put the system into the sleep state: using the platform driver (e.g. ACPI + * or other hibernation_ops), powering it off or rebooting it (for testing + * mostly), or using one of the two available test modes. * - * show() will display what the mode is currently set to. - * store() will accept one of + * The sysfs file /sys/power/disk provides an interface for selecting the + * hibernation mode to use. Reading from this file causes the available modes + * to be printed. There are 5 modes that can be supported: * * 'platform' * 'shutdown' @@ -841,8 +838,14 @@ static const char * const hibernation_modes[] = { * 'test' * 'testproc' * - * It will only change to 'platform' if the system - * supports it (as determined by having hibernation_ops). + * If a platform hibernation driver is in use, 'platform' will be supported + * and will be used by default. Otherwise, 'shutdown' will be used by default. + * The selected option (i.e. the one corresponding to the current value of + * hibernation_mode) is enclosed by a square bracket. + * + * To select a given hibernation mode it is necessary to write the mode's + * string representation (as returned by reading from /sys/power/disk) back + * into /sys/power/disk. */ static ssize_t disk_show(struct kobject *kobj, struct kobj_attribute *attr, @@ -875,7 +878,6 @@ static ssize_t disk_show(struct kobject *kobj, struct kobj_attribute *attr, return buf-start; } - static ssize_t disk_store(struct kobject *kobj, struct kobj_attribute *attr, const char *buf, size_t n) { diff --git a/kernel/printk.c b/kernel/printk.c index da8ca81..3518539 100644 --- a/kernel/printk.c +++ b/kernel/printk.c @@ -31,6 +31,7 @@ #include <linux/smp.h> #include <linux/security.h> #include <linux/bootmem.h> +#include <linux/memblock.h> #include <linux/syscalls.h> #include <linux/kexec.h> #include <linux/kdb.h> @@ -167,46 +168,74 @@ void log_buf_kexec_setup(void) } #endif +/* requested log_buf_len from kernel cmdline */ +static unsigned long __initdata new_log_buf_len; + +/* save requested log_buf_len since it's too early to process it */ static int __init log_buf_len_setup(char *str) { unsigned size = memparse(str, &str); - unsigned long flags; if (size) size = roundup_pow_of_two(size); - if (size > log_buf_len) { - unsigned start, dest_idx, offset; - char *new_log_buf; + if (size > log_buf_len) + new_log_buf_len = size; - new_log_buf = alloc_bootmem(size); - if (!new_log_buf) { - printk(KERN_WARNING "log_buf_len: allocation failed\n"); - goto out; - } + return 0; +} +early_param("log_buf_len", log_buf_len_setup); - spin_lock_irqsave(&logbuf_lock, flags); - log_buf_len = size; - log_buf = new_log_buf; - - offset = start = min(con_start, log_start); - dest_idx = 0; - while (start != log_end) { - log_buf[dest_idx] = __log_buf[start & (__LOG_BUF_LEN - 1)]; - start++; - dest_idx++; - } - log_start -= offset; - con_start -= offset; - log_end -= offset; - spin_unlock_irqrestore(&logbuf_lock, flags); +void __init setup_log_buf(int early) +{ + unsigned long flags; + unsigned start, dest_idx, offset; + char *new_log_buf; + int free; + + if (!new_log_buf_len) + return; + + if (early) { + unsigned long mem; - printk(KERN_NOTICE "log_buf_len: %d\n", log_buf_len); + mem = memblock_alloc(new_log_buf_len, PAGE_SIZE); + if (mem == MEMBLOCK_ERROR) + return; + new_log_buf = __va(mem); + } else { + new_log_buf = alloc_bootmem_nopanic(new_log_buf_len); } -out: - return 1; -} -__setup("log_buf_len=", log_buf_len_setup); + if (unlikely(!new_log_buf)) { + pr_err("log_buf_len: %ld bytes not available\n", + new_log_buf_len); + return; + } + + spin_lock_irqsave(&logbuf_lock, flags); + log_buf_len = new_log_buf_len; + log_buf = new_log_buf; + new_log_buf_len = 0; + free = __LOG_BUF_LEN - log_end; + + offset = start = min(con_start, log_start); + dest_idx = 0; + while (start != log_end) { + unsigned log_idx_mask = start & (__LOG_BUF_LEN - 1); + + log_buf[dest_idx] = __log_buf[log_idx_mask]; + start++; + dest_idx++; + } + log_start -= offset; + con_start -= offset; + log_end -= offset; + spin_unlock_irqrestore(&logbuf_lock, flags); + + pr_info("log_buf_len: %d\n", log_buf_len); + pr_info("early log buf free: %d(%d%%)\n", + free, (free * 100) / __LOG_BUF_LEN); +} #ifdef CONFIG_BOOT_PRINTK_DELAY diff --git a/kernel/profile.c b/kernel/profile.c index 14c9f87..961b389 100644 --- a/kernel/profile.c +++ b/kernel/profile.c @@ -303,14 +303,12 @@ static void profile_discard_flip_buffers(void) mutex_unlock(&profile_flip_mutex); } -void profile_hits(int type, void *__pc, unsigned int nr_hits) +static void do_profile_hits(int type, void *__pc, unsigned int nr_hits) { unsigned long primary, secondary, flags, pc = (unsigned long)__pc; int i, j, cpu; struct profile_hit *hits; - if (prof_on != type || !prof_buffer) - return; pc = min((pc - (unsigned long)_stext) >> prof_shift, prof_len - 1); i = primary = (pc & (NR_PROFILE_GRP - 1)) << PROFILE_GRPSHIFT; secondary = (~(pc << 1) & (NR_PROFILE_GRP - 1)) << PROFILE_GRPSHIFT; @@ -417,16 +415,20 @@ out_free: #define profile_discard_flip_buffers() do { } while (0) #define profile_cpu_callback NULL -void profile_hits(int type, void *__pc, unsigned int nr_hits) +static void do_profile_hits(int type, void *__pc, unsigned int nr_hits) { unsigned long pc; - - if (prof_on != type || !prof_buffer) - return; pc = ((unsigned long)__pc - (unsigned long)_stext) >> prof_shift; atomic_add(nr_hits, &prof_buffer[min(pc, prof_len - 1)]); } #endif /* !CONFIG_SMP */ + +void profile_hits(int type, void *__pc, unsigned int nr_hits) +{ + if (prof_on != type || !prof_buffer) + return; + do_profile_hits(type, __pc, nr_hits); +} EXPORT_SYMBOL_GPL(profile_hits); void profile_tick(int type) diff --git a/kernel/ptrace.c b/kernel/ptrace.c index 7a81fc0..2df1157 100644 --- a/kernel/ptrace.c +++ b/kernel/ptrace.c @@ -562,7 +562,7 @@ static int ptrace_resume(struct task_struct *child, long request, } child->exit_code = data; - wake_up_process(child); + wake_up_state(child, __TASK_TRACED); return 0; } diff --git a/kernel/rcutree.c b/kernel/rcutree.c index f07d2f0..89419ff 100644 --- a/kernel/rcutree.c +++ b/kernel/rcutree.c @@ -36,7 +36,7 @@ #include <linux/interrupt.h> #include <linux/sched.h> #include <linux/nmi.h> -#include <asm/atomic.h> +#include <linux/atomic.h> #include <linux/bitops.h> #include <linux/module.h> #include <linux/completion.h> @@ -95,7 +95,6 @@ static DEFINE_PER_CPU(struct task_struct *, rcu_cpu_kthread_task); DEFINE_PER_CPU(unsigned int, rcu_cpu_kthread_status); DEFINE_PER_CPU(int, rcu_cpu_kthread_cpu); DEFINE_PER_CPU(unsigned int, rcu_cpu_kthread_loops); -static DEFINE_PER_CPU(wait_queue_head_t, rcu_cpu_wq); DEFINE_PER_CPU(char, rcu_cpu_has_work); static char rcu_kthreads_spawnable; @@ -163,7 +162,7 @@ EXPORT_SYMBOL_GPL(rcu_note_context_switch); #ifdef CONFIG_NO_HZ DEFINE_PER_CPU(struct rcu_dynticks, rcu_dynticks) = { .dynticks_nesting = 1, - .dynticks = 1, + .dynticks = ATOMIC_INIT(1), }; #endif /* #ifdef CONFIG_NO_HZ */ @@ -322,13 +321,25 @@ void rcu_enter_nohz(void) unsigned long flags; struct rcu_dynticks *rdtp; - smp_mb(); /* CPUs seeing ++ must see prior RCU read-side crit sects */ local_irq_save(flags); rdtp = &__get_cpu_var(rcu_dynticks); - rdtp->dynticks++; - rdtp->dynticks_nesting--; - WARN_ON_ONCE(rdtp->dynticks & 0x1); + if (--rdtp->dynticks_nesting) { + local_irq_restore(flags); + return; + } + /* CPUs seeing atomic_inc() must see prior RCU read-side crit sects */ + smp_mb__before_atomic_inc(); /* See above. */ + atomic_inc(&rdtp->dynticks); + smp_mb__after_atomic_inc(); /* Force ordering with next sojourn. */ + WARN_ON_ONCE(atomic_read(&rdtp->dynticks) & 0x1); local_irq_restore(flags); + + /* If the interrupt queued a callback, get out of dyntick mode. */ + if (in_irq() && + (__get_cpu_var(rcu_sched_data).nxtlist || + __get_cpu_var(rcu_bh_data).nxtlist || + rcu_preempt_needs_cpu(smp_processor_id()))) + set_need_resched(); } /* @@ -344,11 +355,16 @@ void rcu_exit_nohz(void) local_irq_save(flags); rdtp = &__get_cpu_var(rcu_dynticks); - rdtp->dynticks++; - rdtp->dynticks_nesting++; - WARN_ON_ONCE(!(rdtp->dynticks & 0x1)); + if (rdtp->dynticks_nesting++) { + local_irq_restore(flags); + return; + } + smp_mb__before_atomic_inc(); /* Force ordering w/previous sojourn. */ + atomic_inc(&rdtp->dynticks); + /* CPUs seeing atomic_inc() must see later RCU read-side crit sects */ + smp_mb__after_atomic_inc(); /* See above. */ + WARN_ON_ONCE(!(atomic_read(&rdtp->dynticks) & 0x1)); local_irq_restore(flags); - smp_mb(); /* CPUs seeing ++ must see later RCU read-side crit sects */ } /** @@ -362,11 +378,15 @@ void rcu_nmi_enter(void) { struct rcu_dynticks *rdtp = &__get_cpu_var(rcu_dynticks); - if (rdtp->dynticks & 0x1) + if (rdtp->dynticks_nmi_nesting == 0 && + (atomic_read(&rdtp->dynticks) & 0x1)) return; - rdtp->dynticks_nmi++; - WARN_ON_ONCE(!(rdtp->dynticks_nmi & 0x1)); - smp_mb(); /* CPUs seeing ++ must see later RCU read-side crit sects */ + rdtp->dynticks_nmi_nesting++; + smp_mb__before_atomic_inc(); /* Force delay from prior write. */ + atomic_inc(&rdtp->dynticks); + /* CPUs seeing atomic_inc() must see later RCU read-side crit sects */ + smp_mb__after_atomic_inc(); /* See above. */ + WARN_ON_ONCE(!(atomic_read(&rdtp->dynticks) & 0x1)); } /** @@ -380,11 +400,14 @@ void rcu_nmi_exit(void) { struct rcu_dynticks *rdtp = &__get_cpu_var(rcu_dynticks); - if (rdtp->dynticks & 0x1) + if (rdtp->dynticks_nmi_nesting == 0 || + --rdtp->dynticks_nmi_nesting != 0) return; - smp_mb(); /* CPUs seeing ++ must see prior RCU read-side crit sects */ - rdtp->dynticks_nmi++; - WARN_ON_ONCE(rdtp->dynticks_nmi & 0x1); + /* CPUs seeing atomic_inc() must see prior RCU read-side crit sects */ + smp_mb__before_atomic_inc(); /* See above. */ + atomic_inc(&rdtp->dynticks); + smp_mb__after_atomic_inc(); /* Force delay to next write. */ + WARN_ON_ONCE(atomic_read(&rdtp->dynticks) & 0x1); } /** @@ -395,13 +418,7 @@ void rcu_nmi_exit(void) */ void rcu_irq_enter(void) { - struct rcu_dynticks *rdtp = &__get_cpu_var(rcu_dynticks); - - if (rdtp->dynticks_nesting++) - return; - rdtp->dynticks++; - WARN_ON_ONCE(!(rdtp->dynticks & 0x1)); - smp_mb(); /* CPUs seeing ++ must see later RCU read-side crit sects */ + rcu_exit_nohz(); } /** @@ -413,18 +430,7 @@ void rcu_irq_enter(void) */ void rcu_irq_exit(void) { - struct rcu_dynticks *rdtp = &__get_cpu_var(rcu_dynticks); - - if (--rdtp->dynticks_nesting) - return; - smp_mb(); /* CPUs seeing ++ must see prior RCU read-side crit sects */ - rdtp->dynticks++; - WARN_ON_ONCE(rdtp->dynticks & 0x1); - - /* If the interrupt queued a callback, get out of dyntick mode. */ - if (__this_cpu_read(rcu_sched_data.nxtlist) || - __this_cpu_read(rcu_bh_data.nxtlist)) - set_need_resched(); + rcu_enter_nohz(); } #ifdef CONFIG_SMP @@ -436,19 +442,8 @@ void rcu_irq_exit(void) */ static int dyntick_save_progress_counter(struct rcu_data *rdp) { - int ret; - int snap; - int snap_nmi; - - snap = rdp->dynticks->dynticks; - snap_nmi = rdp->dynticks->dynticks_nmi; - smp_mb(); /* Order sampling of snap with end of grace period. */ - rdp->dynticks_snap = snap; - rdp->dynticks_nmi_snap = snap_nmi; - ret = ((snap & 0x1) == 0) && ((snap_nmi & 0x1) == 0); - if (ret) - rdp->dynticks_fqs++; - return ret; + rdp->dynticks_snap = atomic_add_return(0, &rdp->dynticks->dynticks); + return 0; } /* @@ -459,16 +454,11 @@ static int dyntick_save_progress_counter(struct rcu_data *rdp) */ static int rcu_implicit_dynticks_qs(struct rcu_data *rdp) { - long curr; - long curr_nmi; - long snap; - long snap_nmi; + unsigned long curr; + unsigned long snap; - curr = rdp->dynticks->dynticks; - snap = rdp->dynticks_snap; - curr_nmi = rdp->dynticks->dynticks_nmi; - snap_nmi = rdp->dynticks_nmi_snap; - smp_mb(); /* force ordering with cpu entering/leaving dynticks. */ + curr = (unsigned long)atomic_add_return(0, &rdp->dynticks->dynticks); + snap = (unsigned long)rdp->dynticks_snap; /* * If the CPU passed through or entered a dynticks idle phase with @@ -478,8 +468,7 @@ static int rcu_implicit_dynticks_qs(struct rcu_data *rdp) * read-side critical section that started before the beginning * of the current RCU grace period. */ - if ((curr != snap || (curr & 0x1) == 0) && - (curr_nmi != snap_nmi || (curr_nmi & 0x1) == 0)) { + if ((curr & 0x1) == 0 || ULONG_CMP_GE(curr, snap + 2)) { rdp->dynticks_fqs++; return 1; } @@ -908,6 +897,12 @@ static void rcu_report_qs_rsp(struct rcu_state *rsp, unsigned long flags) unsigned long gp_duration; WARN_ON_ONCE(!rcu_gp_in_progress(rsp)); + + /* + * Ensure that all grace-period and pre-grace-period activity + * is seen before the assignment to rsp->completed. + */ + smp_mb(); /* See above block comment. */ gp_duration = jiffies - rsp->gp_start; if (gp_duration > rsp->gp_max) rsp->gp_max = gp_duration; @@ -1455,25 +1450,11 @@ __rcu_process_callbacks(struct rcu_state *rsp, struct rcu_data *rdp) */ static void rcu_process_callbacks(void) { - /* - * Memory references from any prior RCU read-side critical sections - * executed by the interrupted code must be seen before any RCU - * grace-period manipulations below. - */ - smp_mb(); /* See above block comment. */ - __rcu_process_callbacks(&rcu_sched_state, &__get_cpu_var(rcu_sched_data)); __rcu_process_callbacks(&rcu_bh_state, &__get_cpu_var(rcu_bh_data)); rcu_preempt_process_callbacks(); - /* - * Memory references from any later RCU read-side critical sections - * executed by the interrupted code must be seen after any RCU - * grace-period manipulations above. - */ - smp_mb(); /* See above block comment. */ - /* If we are last CPU on way to dyntick-idle mode, accelerate it. */ rcu_needs_cpu_flush(); } @@ -1494,7 +1475,7 @@ static void invoke_rcu_cpu_kthread(void) local_irq_restore(flags); return; } - wake_up(&__get_cpu_var(rcu_cpu_wq)); + wake_up_process(__this_cpu_read(rcu_cpu_kthread_task)); local_irq_restore(flags); } @@ -1544,13 +1525,10 @@ static void rcu_cpu_kthread_setrt(int cpu, int to_rt) */ static void rcu_cpu_kthread_timer(unsigned long arg) { - unsigned long flags; struct rcu_data *rdp = per_cpu_ptr(rcu_state->rda, arg); struct rcu_node *rnp = rdp->mynode; - raw_spin_lock_irqsave(&rnp->lock, flags); - rnp->wakemask |= rdp->grpmask; - raw_spin_unlock_irqrestore(&rnp->lock, flags); + atomic_or(rdp->grpmask, &rnp->wakemask); invoke_rcu_node_kthread(rnp); } @@ -1617,14 +1595,12 @@ static int rcu_cpu_kthread(void *arg) unsigned long flags; int spincnt = 0; unsigned int *statusp = &per_cpu(rcu_cpu_kthread_status, cpu); - wait_queue_head_t *wqp = &per_cpu(rcu_cpu_wq, cpu); char work; char *workp = &per_cpu(rcu_cpu_has_work, cpu); for (;;) { *statusp = RCU_KTHREAD_WAITING; - wait_event_interruptible(*wqp, - *workp != 0 || kthread_should_stop()); + rcu_wait(*workp != 0 || kthread_should_stop()); local_bh_disable(); if (rcu_cpu_kthread_should_stop(cpu)) { local_bh_enable(); @@ -1675,7 +1651,6 @@ static int __cpuinit rcu_spawn_one_cpu_kthread(int cpu) per_cpu(rcu_cpu_kthread_cpu, cpu) = cpu; WARN_ON_ONCE(per_cpu(rcu_cpu_kthread_task, cpu) != NULL); per_cpu(rcu_cpu_kthread_task, cpu) = t; - wake_up_process(t); sp.sched_priority = RCU_KTHREAD_PRIO; sched_setscheduler_nocheck(t, SCHED_FIFO, &sp); return 0; @@ -1698,11 +1673,10 @@ static int rcu_node_kthread(void *arg) for (;;) { rnp->node_kthread_status = RCU_KTHREAD_WAITING; - wait_event_interruptible(rnp->node_wq, rnp->wakemask != 0); + rcu_wait(atomic_read(&rnp->wakemask) != 0); rnp->node_kthread_status = RCU_KTHREAD_RUNNING; raw_spin_lock_irqsave(&rnp->lock, flags); - mask = rnp->wakemask; - rnp->wakemask = 0; + mask = atomic_xchg(&rnp->wakemask, 0); rcu_initiate_boost(rnp, flags); /* releases rnp->lock. */ for (cpu = rnp->grplo; cpu <= rnp->grphi; cpu++, mask >>= 1) { if ((mask & 0x1) == 0) @@ -1783,13 +1757,14 @@ static int __cpuinit rcu_spawn_one_node_kthread(struct rcu_state *rsp, raw_spin_lock_irqsave(&rnp->lock, flags); rnp->node_kthread_task = t; raw_spin_unlock_irqrestore(&rnp->lock, flags); - wake_up_process(t); sp.sched_priority = 99; sched_setscheduler_nocheck(t, SCHED_FIFO, &sp); } return rcu_spawn_one_boost_kthread(rsp, rnp, rnp_index); } +static void rcu_wake_one_boost_kthread(struct rcu_node *rnp); + /* * Spawn all kthreads -- called as soon as the scheduler is running. */ @@ -1797,24 +1772,31 @@ static int __init rcu_spawn_kthreads(void) { int cpu; struct rcu_node *rnp; + struct task_struct *t; rcu_kthreads_spawnable = 1; for_each_possible_cpu(cpu) { - init_waitqueue_head(&per_cpu(rcu_cpu_wq, cpu)); per_cpu(rcu_cpu_has_work, cpu) = 0; - if (cpu_online(cpu)) + if (cpu_online(cpu)) { (void)rcu_spawn_one_cpu_kthread(cpu); + t = per_cpu(rcu_cpu_kthread_task, cpu); + if (t) + wake_up_process(t); + } } rnp = rcu_get_root(rcu_state); - init_waitqueue_head(&rnp->node_wq); - rcu_init_boost_waitqueue(rnp); (void)rcu_spawn_one_node_kthread(rcu_state, rnp); - if (NUM_RCU_NODES > 1) + if (rnp->node_kthread_task) + wake_up_process(rnp->node_kthread_task); + if (NUM_RCU_NODES > 1) { rcu_for_each_leaf_node(rcu_state, rnp) { - init_waitqueue_head(&rnp->node_wq); - rcu_init_boost_waitqueue(rnp); (void)rcu_spawn_one_node_kthread(rcu_state, rnp); + t = rnp->node_kthread_task; + if (t) + wake_up_process(t); + rcu_wake_one_boost_kthread(rnp); } + } return 0; } early_initcall(rcu_spawn_kthreads); @@ -2218,14 +2200,14 @@ rcu_init_percpu_data(int cpu, struct rcu_state *rsp, int preemptible) raw_spin_unlock_irqrestore(&rsp->onofflock, flags); } -static void __cpuinit rcu_online_cpu(int cpu) +static void __cpuinit rcu_prepare_cpu(int cpu) { rcu_init_percpu_data(cpu, &rcu_sched_state, 0); rcu_init_percpu_data(cpu, &rcu_bh_state, 0); rcu_preempt_init_percpu_data(cpu); } -static void __cpuinit rcu_online_kthreads(int cpu) +static void __cpuinit rcu_prepare_kthreads(int cpu) { struct rcu_data *rdp = per_cpu_ptr(rcu_state->rda, cpu); struct rcu_node *rnp = rdp->mynode; @@ -2239,6 +2221,31 @@ static void __cpuinit rcu_online_kthreads(int cpu) } /* + * kthread_create() creates threads in TASK_UNINTERRUPTIBLE state, + * but the RCU threads are woken on demand, and if demand is low this + * could be a while triggering the hung task watchdog. + * + * In order to avoid this, poke all tasks once the CPU is fully + * up and running. + */ +static void __cpuinit rcu_online_kthreads(int cpu) +{ + struct rcu_data *rdp = per_cpu_ptr(rcu_state->rda, cpu); + struct rcu_node *rnp = rdp->mynode; + struct task_struct *t; + + t = per_cpu(rcu_cpu_kthread_task, cpu); + if (t) + wake_up_process(t); + + t = rnp->node_kthread_task; + if (t) + wake_up_process(t); + + rcu_wake_one_boost_kthread(rnp); +} + +/* * Handle CPU online/offline notification events. */ static int __cpuinit rcu_cpu_notify(struct notifier_block *self, @@ -2251,10 +2258,11 @@ static int __cpuinit rcu_cpu_notify(struct notifier_block *self, switch (action) { case CPU_UP_PREPARE: case CPU_UP_PREPARE_FROZEN: - rcu_online_cpu(cpu); - rcu_online_kthreads(cpu); + rcu_prepare_cpu(cpu); + rcu_prepare_kthreads(cpu); break; case CPU_ONLINE: + rcu_online_kthreads(cpu); case CPU_DOWN_FAILED: rcu_node_kthread_setaffinity(rnp, -1); rcu_cpu_kthread_setrt(cpu, 1); diff --git a/kernel/rcutree.h b/kernel/rcutree.h index 2576648..7b9a08b 100644 --- a/kernel/rcutree.h +++ b/kernel/rcutree.h @@ -84,11 +84,9 @@ * Dynticks per-CPU state. */ struct rcu_dynticks { - int dynticks_nesting; /* Track nesting level, sort of. */ - int dynticks; /* Even value for dynticks-idle, else odd. */ - int dynticks_nmi; /* Even value for either dynticks-idle or */ - /* not in nmi handler, else odd. So this */ - /* remains even for nmi from irq handler. */ + int dynticks_nesting; /* Track irq/process nesting level. */ + int dynticks_nmi_nesting; /* Track NMI nesting level. */ + atomic_t dynticks; /* Even value for dynticks-idle, else odd. */ }; /* RCU's kthread states for tracing. */ @@ -121,7 +119,9 @@ struct rcu_node { /* elements that need to drain to allow the */ /* current expedited grace period to */ /* complete (only for TREE_PREEMPT_RCU). */ - unsigned long wakemask; /* CPUs whose kthread needs to be awakened. */ + atomic_t wakemask; /* CPUs whose kthread needs to be awakened. */ + /* Since this has meaning only for leaf */ + /* rcu_node structures, 32 bits suffices. */ unsigned long qsmaskinit; /* Per-GP initial value for qsmask & expmask. */ unsigned long grpmask; /* Mask to apply to parent qsmask. */ @@ -159,9 +159,6 @@ struct rcu_node { struct task_struct *boost_kthread_task; /* kthread that takes care of priority */ /* boosting for this rcu_node structure. */ - wait_queue_head_t boost_wq; - /* Wait queue on which to park the boost */ - /* kthread. */ unsigned int boost_kthread_status; /* State of boost_kthread_task for tracing. */ unsigned long n_tasks_boosted; @@ -188,9 +185,6 @@ struct rcu_node { /* kthread that takes care of this rcu_node */ /* structure, for example, awakening the */ /* per-CPU kthreads as needed. */ - wait_queue_head_t node_wq; - /* Wait queue on which to park the per-node */ - /* kthread. */ unsigned int node_kthread_status; /* State of node_kthread_task for tracing. */ } ____cacheline_internodealigned_in_smp; @@ -284,7 +278,6 @@ struct rcu_data { /* 3) dynticks interface. */ struct rcu_dynticks *dynticks; /* Shared per-CPU dynticks state. */ int dynticks_snap; /* Per-GP tracking for dynticks. */ - int dynticks_nmi_snap; /* Per-GP tracking for dynticks_nmi. */ #endif /* #ifdef CONFIG_NO_HZ */ /* 4) reasons this CPU needed to be kicked by force_quiescent_state */ @@ -337,6 +330,16 @@ struct rcu_data { /* scheduling clock irq */ /* before ratting on them. */ +#define rcu_wait(cond) \ +do { \ + for (;;) { \ + set_current_state(TASK_INTERRUPTIBLE); \ + if (cond) \ + break; \ + schedule(); \ + } \ + __set_current_state(TASK_RUNNING); \ +} while (0) /* * RCU global state, including node hierarchy. This hierarchy is @@ -446,7 +449,6 @@ static void __cpuinit rcu_preempt_init_percpu_data(int cpu); static void rcu_preempt_send_cbs_to_online(void); static void __init __rcu_init_preempt(void); static void rcu_needs_cpu_flush(void); -static void __init rcu_init_boost_waitqueue(struct rcu_node *rnp); static void rcu_initiate_boost(struct rcu_node *rnp, unsigned long flags); static void rcu_boost_kthread_setaffinity(struct rcu_node *rnp, cpumask_var_t cm); diff --git a/kernel/rcutree_plugin.h b/kernel/rcutree_plugin.h index 3f6559a..c8bff30 100644 --- a/kernel/rcutree_plugin.h +++ b/kernel/rcutree_plugin.h @@ -1196,8 +1196,7 @@ static int rcu_boost_kthread(void *arg) for (;;) { rnp->boost_kthread_status = RCU_KTHREAD_WAITING; - wait_event_interruptible(rnp->boost_wq, rnp->boost_tasks || - rnp->exp_tasks); + rcu_wait(rnp->boost_tasks || rnp->exp_tasks); rnp->boost_kthread_status = RCU_KTHREAD_RUNNING; more2boost = rcu_boost(rnp); if (more2boost) @@ -1275,14 +1274,6 @@ static void rcu_preempt_boost_start_gp(struct rcu_node *rnp) } /* - * Initialize the RCU-boost waitqueue. - */ -static void __init rcu_init_boost_waitqueue(struct rcu_node *rnp) -{ - init_waitqueue_head(&rnp->boost_wq); -} - -/* * Create an RCU-boost kthread for the specified node if one does not * already exist. We only create this kthread for preemptible RCU. * Returns zero if all is well, a negated errno otherwise. @@ -1306,12 +1297,17 @@ static int __cpuinit rcu_spawn_one_boost_kthread(struct rcu_state *rsp, raw_spin_lock_irqsave(&rnp->lock, flags); rnp->boost_kthread_task = t; raw_spin_unlock_irqrestore(&rnp->lock, flags); - wake_up_process(t); sp.sched_priority = RCU_KTHREAD_PRIO; sched_setscheduler_nocheck(t, SCHED_FIFO, &sp); return 0; } +static void __cpuinit rcu_wake_one_boost_kthread(struct rcu_node *rnp) +{ + if (rnp->boost_kthread_task) + wake_up_process(rnp->boost_kthread_task); +} + #else /* #ifdef CONFIG_RCU_BOOST */ static void rcu_initiate_boost(struct rcu_node *rnp, unsigned long flags) @@ -1328,10 +1324,6 @@ static void rcu_preempt_boost_start_gp(struct rcu_node *rnp) { } -static void __init rcu_init_boost_waitqueue(struct rcu_node *rnp) -{ -} - static int __cpuinit rcu_spawn_one_boost_kthread(struct rcu_state *rsp, struct rcu_node *rnp, int rnp_index) @@ -1339,6 +1331,10 @@ static int __cpuinit rcu_spawn_one_boost_kthread(struct rcu_state *rsp, return 0; } +static void __cpuinit rcu_wake_one_boost_kthread(struct rcu_node *rnp) +{ +} + #endif /* #else #ifdef CONFIG_RCU_BOOST */ #ifndef CONFIG_SMP @@ -1520,7 +1516,6 @@ int rcu_needs_cpu(int cpu) { int c = 0; int snap; - int snap_nmi; int thatcpu; /* Check for being in the holdoff period. */ @@ -1531,10 +1526,10 @@ int rcu_needs_cpu(int cpu) for_each_online_cpu(thatcpu) { if (thatcpu == cpu) continue; - snap = per_cpu(rcu_dynticks, thatcpu).dynticks; - snap_nmi = per_cpu(rcu_dynticks, thatcpu).dynticks_nmi; + snap = atomic_add_return(0, &per_cpu(rcu_dynticks, + thatcpu).dynticks); smp_mb(); /* Order sampling of snap with end of grace period. */ - if (((snap & 0x1) != 0) || ((snap_nmi & 0x1) != 0)) { + if ((snap & 0x1) != 0) { per_cpu(rcu_dyntick_drain, cpu) = 0; per_cpu(rcu_dyntick_holdoff, cpu) = jiffies - 1; return rcu_needs_cpu_quick_check(cpu); diff --git a/kernel/rcutree_trace.c b/kernel/rcutree_trace.c index aa0fd72..9678cc3 100644 --- a/kernel/rcutree_trace.c +++ b/kernel/rcutree_trace.c @@ -69,10 +69,10 @@ static void print_one_rcu_data(struct seq_file *m, struct rcu_data *rdp) rdp->passed_quiesc, rdp->passed_quiesc_completed, rdp->qs_pending); #ifdef CONFIG_NO_HZ - seq_printf(m, " dt=%d/%d dn=%d df=%lu", - rdp->dynticks->dynticks, + seq_printf(m, " dt=%d/%d/%d df=%lu", + atomic_read(&rdp->dynticks->dynticks), rdp->dynticks->dynticks_nesting, - rdp->dynticks->dynticks_nmi, + rdp->dynticks->dynticks_nmi_nesting, rdp->dynticks_fqs); #endif /* #ifdef CONFIG_NO_HZ */ seq_printf(m, " of=%lu ri=%lu", rdp->offline_fqs, rdp->resched_ipi); @@ -141,9 +141,9 @@ static void print_one_rcu_data_csv(struct seq_file *m, struct rcu_data *rdp) rdp->qs_pending); #ifdef CONFIG_NO_HZ seq_printf(m, ",%d,%d,%d,%lu", - rdp->dynticks->dynticks, + atomic_read(&rdp->dynticks->dynticks), rdp->dynticks->dynticks_nesting, - rdp->dynticks->dynticks_nmi, + rdp->dynticks->dynticks_nmi_nesting, rdp->dynticks_fqs); #endif /* #ifdef CONFIG_NO_HZ */ seq_printf(m, ",%lu,%lu", rdp->offline_fqs, rdp->resched_ipi); @@ -167,7 +167,7 @@ static int show_rcudata_csv(struct seq_file *m, void *unused) { seq_puts(m, "\"CPU\",\"Online?\",\"c\",\"g\",\"pq\",\"pqc\",\"pq\","); #ifdef CONFIG_NO_HZ - seq_puts(m, "\"dt\",\"dt nesting\",\"dn\",\"df\","); + seq_puts(m, "\"dt\",\"dt nesting\",\"dt NMI nesting\",\"df\","); #endif /* #ifdef CONFIG_NO_HZ */ seq_puts(m, "\"of\",\"ri\",\"ql\",\"b\",\"ci\",\"co\",\"ca\"\n"); #ifdef CONFIG_TREE_PREEMPT_RCU diff --git a/kernel/sched.c b/kernel/sched.c index 2d12893..3f2e502 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -605,10 +605,10 @@ static inline int cpu_of(struct rq *rq) /* * Return the group to which this tasks belongs. * - * We use task_subsys_state_check() and extend the RCU verification - * with lockdep_is_held(&p->pi_lock) because cpu_cgroup_attach() - * holds that lock for each task it moves into the cgroup. Therefore - * by holding that lock, we pin the task to the current cgroup. + * We use task_subsys_state_check() and extend the RCU verification with + * pi->lock and rq->lock because cpu_cgroup_attach() holds those locks for each + * task it moves into the cgroup. Therefore by holding either of those locks, + * we pin the task to the current cgroup. */ static inline struct task_group *task_group(struct task_struct *p) { @@ -616,7 +616,8 @@ static inline struct task_group *task_group(struct task_struct *p) struct cgroup_subsys_state *css; css = task_subsys_state_check(p, cpu_cgroup_subsys_id, - lockdep_is_held(&p->pi_lock)); + lockdep_is_held(&p->pi_lock) || + lockdep_is_held(&task_rq(p)->lock)); tg = container_of(css, struct task_group, css); return autogroup_task_group(p, tg); @@ -2200,6 +2201,16 @@ void set_task_cpu(struct task_struct *p, unsigned int new_cpu) !(task_thread_info(p)->preempt_count & PREEMPT_ACTIVE)); #ifdef CONFIG_LOCKDEP + /* + * The caller should hold either p->pi_lock or rq->lock, when changing + * a task's CPU. ->pi_lock for waking tasks, rq->lock for runnable tasks. + * + * sched_move_task() holds both and thus holding either pins the cgroup, + * see set_task_rq(). + * + * Furthermore, all task_rq users should acquire both locks, see + * task_rq_lock(). + */ WARN_ON_ONCE(debug_locks && !(lockdep_is_held(&p->pi_lock) || lockdep_is_held(&task_rq(p)->lock))); #endif @@ -2447,6 +2458,10 @@ ttwu_stat(struct task_struct *p, int cpu, int wake_flags) } rcu_read_unlock(); } + + if (wake_flags & WF_MIGRATED) + schedstat_inc(p, se.statistics.nr_wakeups_migrate); + #endif /* CONFIG_SMP */ schedstat_inc(rq, ttwu_count); @@ -2455,9 +2470,6 @@ ttwu_stat(struct task_struct *p, int cpu, int wake_flags) if (wake_flags & WF_SYNC) schedstat_inc(p, se.statistics.nr_wakeups_sync); - if (cpu != task_cpu(p)) - schedstat_inc(p, se.statistics.nr_wakeups_migrate); - #endif /* CONFIG_SCHEDSTATS */ } @@ -2573,7 +2585,26 @@ static void ttwu_queue_remote(struct task_struct *p, int cpu) if (!next) smp_send_reschedule(cpu); } -#endif + +#ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW +static int ttwu_activate_remote(struct task_struct *p, int wake_flags) +{ + struct rq *rq; + int ret = 0; + + rq = __task_rq_lock(p); + if (p->on_cpu) { + ttwu_activate(rq, p, ENQUEUE_WAKEUP); + ttwu_do_wakeup(rq, p, wake_flags); + ret = 1; + } + __task_rq_unlock(rq); + + return ret; + +} +#endif /* __ARCH_WANT_INTERRUPTS_ON_CTXSW */ +#endif /* CONFIG_SMP */ static void ttwu_queue(struct task_struct *p, int cpu) { @@ -2581,6 +2612,7 @@ static void ttwu_queue(struct task_struct *p, int cpu) #if defined(CONFIG_SMP) if (sched_feat(TTWU_QUEUE) && cpu != smp_processor_id()) { + sched_clock_cpu(cpu); /* sync clocks x-cpu */ ttwu_queue_remote(p, cpu); return; } @@ -2631,17 +2663,17 @@ try_to_wake_up(struct task_struct *p, unsigned int state, int wake_flags) while (p->on_cpu) { #ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW /* - * If called from interrupt context we could have landed in the - * middle of schedule(), in this case we should take care not - * to spin on ->on_cpu if p is current, since that would - * deadlock. + * In case the architecture enables interrupts in + * context_switch(), we cannot busy wait, since that + * would lead to deadlocks when an interrupt hits and + * tries to wake up @prev. So bail and do a complete + * remote wakeup. */ - if (p == current) { - ttwu_queue(p, cpu); + if (ttwu_activate_remote(p, wake_flags)) goto stat; - } -#endif +#else cpu_relax(); +#endif } /* * Pairs with the smp_wmb() in finish_lock_switch(). @@ -2655,8 +2687,10 @@ try_to_wake_up(struct task_struct *p, unsigned int state, int wake_flags) p->sched_class->task_waking(p); cpu = select_task_rq(p, SD_BALANCE_WAKE, wake_flags); - if (task_cpu(p) != cpu) + if (task_cpu(p) != cpu) { + wake_flags |= WF_MIGRATED; set_task_cpu(p, cpu); + } #endif /* CONFIG_SMP */ ttwu_queue(p, cpu); @@ -5841,7 +5875,7 @@ void __cpuinit init_idle(struct task_struct *idle, int cpu) idle->state = TASK_RUNNING; idle->se.exec_start = sched_clock(); - cpumask_copy(&idle->cpus_allowed, cpumask_of(cpu)); + do_set_cpus_allowed(idle, cpumask_of(cpu)); /* * We're having a chicken and egg problem, even though we are * holding rq->lock, the cpu isn't yet set to this cpu so the @@ -5929,6 +5963,16 @@ static inline void sched_init_granularity(void) } #ifdef CONFIG_SMP +void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask) +{ + if (p->sched_class && p->sched_class->set_cpus_allowed) + p->sched_class->set_cpus_allowed(p, new_mask); + else { + cpumask_copy(&p->cpus_allowed, new_mask); + p->rt.nr_cpus_allowed = cpumask_weight(new_mask); + } +} + /* * This is how migration works: * @@ -5974,12 +6018,7 @@ int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask) goto out; } - if (p->sched_class->set_cpus_allowed) - p->sched_class->set_cpus_allowed(p, new_mask); - else { - cpumask_copy(&p->cpus_allowed, new_mask); - p->rt.nr_cpus_allowed = cpumask_weight(new_mask); - } + do_set_cpus_allowed(p, new_mask); /* Can the task run on the task's current CPU? If so, we're done */ if (cpumask_test_cpu(task_cpu(p), new_mask)) @@ -8764,42 +8803,10 @@ cpu_cgroup_can_attach_task(struct cgroup *cgrp, struct task_struct *tsk) return 0; } -static int -cpu_cgroup_can_attach(struct cgroup_subsys *ss, struct cgroup *cgrp, - struct task_struct *tsk, bool threadgroup) -{ - int retval = cpu_cgroup_can_attach_task(cgrp, tsk); - if (retval) - return retval; - if (threadgroup) { - struct task_struct *c; - rcu_read_lock(); - list_for_each_entry_rcu(c, &tsk->thread_group, thread_group) { - retval = cpu_cgroup_can_attach_task(cgrp, c); - if (retval) { - rcu_read_unlock(); - return retval; - } - } - rcu_read_unlock(); - } - return 0; -} - static void -cpu_cgroup_attach(struct cgroup_subsys *ss, struct cgroup *cgrp, - struct cgroup *old_cont, struct task_struct *tsk, - bool threadgroup) +cpu_cgroup_attach_task(struct cgroup *cgrp, struct task_struct *tsk) { sched_move_task(tsk); - if (threadgroup) { - struct task_struct *c; - rcu_read_lock(); - list_for_each_entry_rcu(c, &tsk->thread_group, thread_group) { - sched_move_task(c); - } - rcu_read_unlock(); - } } static void @@ -8887,8 +8894,8 @@ struct cgroup_subsys cpu_cgroup_subsys = { .name = "cpu", .create = cpu_cgroup_create, .destroy = cpu_cgroup_destroy, - .can_attach = cpu_cgroup_can_attach, - .attach = cpu_cgroup_attach, + .can_attach_task = cpu_cgroup_can_attach_task, + .attach_task = cpu_cgroup_attach_task, .exit = cpu_cgroup_exit, .populate = cpu_cgroup_populate, .subsys_id = cpu_cgroup_subsys_id, diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index e32a9b7..433491c2 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -1076,8 +1076,6 @@ dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags) se->on_rq = 0; update_cfs_load(cfs_rq, 0); account_entity_dequeue(cfs_rq, se); - update_min_vruntime(cfs_rq); - update_cfs_shares(cfs_rq); /* * Normalize the entity after updating the min_vruntime because the @@ -1086,6 +1084,9 @@ dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags) */ if (!(flags & DEQUEUE_SLEEP)) se->vruntime -= cfs_rq->min_vruntime; + + update_min_vruntime(cfs_rq); + update_cfs_shares(cfs_rq); } /* diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c index 64b2a37..88725c9 100644 --- a/kernel/sched_rt.c +++ b/kernel/sched_rt.c @@ -1263,6 +1263,7 @@ static int find_lowest_rq(struct task_struct *task) if (!cpumask_test_cpu(this_cpu, lowest_mask)) this_cpu = -1; /* Skip this_cpu opt if not among lowest */ + rcu_read_lock(); for_each_domain(cpu, sd) { if (sd->flags & SD_WAKE_AFFINE) { int best_cpu; @@ -1272,15 +1273,20 @@ static int find_lowest_rq(struct task_struct *task) * remote processor. */ if (this_cpu != -1 && - cpumask_test_cpu(this_cpu, sched_domain_span(sd))) + cpumask_test_cpu(this_cpu, sched_domain_span(sd))) { + rcu_read_unlock(); return this_cpu; + } best_cpu = cpumask_first_and(lowest_mask, sched_domain_span(sd)); - if (best_cpu < nr_cpu_ids) + if (best_cpu < nr_cpu_ids) { + rcu_read_unlock(); return best_cpu; + } } } + rcu_read_unlock(); /* * And finally, if there were no matches within the domains diff --git a/kernel/sched_stats.h b/kernel/sched_stats.h index 48ddf43..331e01b 100644 --- a/kernel/sched_stats.h +++ b/kernel/sched_stats.h @@ -37,7 +37,7 @@ static int show_schedstat(struct seq_file *seq, void *v) #ifdef CONFIG_SMP /* domain-specific stats */ - preempt_disable(); + rcu_read_lock(); for_each_domain(cpu, sd) { enum cpu_idle_type itype; @@ -64,7 +64,7 @@ static int show_schedstat(struct seq_file *seq, void *v) sd->ttwu_wake_remote, sd->ttwu_move_affine, sd->ttwu_move_balance); } - preempt_enable(); + rcu_read_unlock(); #endif } kfree(mask_str); diff --git a/kernel/signal.c b/kernel/signal.c index ad5e818..86c32b8 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -3023,8 +3023,10 @@ SYSCALL_DEFINE2(signal, int, sig, __sighandler_t, handler) SYSCALL_DEFINE0(pause) { - current->state = TASK_INTERRUPTIBLE; - schedule(); + while (!signal_pending(current)) { + current->state = TASK_INTERRUPTIBLE; + schedule(); + } return -ERESTARTNOHAND; } diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 3dd0c46..f175d98 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -56,6 +56,7 @@ #include <linux/kprobes.h> #include <linux/pipe_fs_i.h> #include <linux/oom.h> +#include <linux/kmod.h> #include <asm/uaccess.h> #include <asm/processor.h> @@ -616,6 +617,11 @@ static struct ctl_table kern_table[] = { .child = random_table, }, { + .procname = "usermodehelper", + .mode = 0555, + .child = usermodehelper_table, + }, + { .procname = "overflowuid", .data = &overflowuid, .maxlen = sizeof(int), @@ -932,6 +938,12 @@ static struct ctl_table kern_table[] = { }, #endif #ifdef CONFIG_PERF_EVENTS + /* + * User-space scripts rely on the existence of this file + * as a feature check for perf_events being enabled. + * + * So it's an ABI, do not remove! + */ { .procname = "perf_event_paranoid", .data = &sysctl_perf_event_paranoid, @@ -1500,7 +1512,7 @@ static struct ctl_table fs_table[] = { static struct ctl_table debug_table[] = { #if defined(CONFIG_X86) || defined(CONFIG_PPC) || defined(CONFIG_SPARC) || \ - defined(CONFIG_S390) + defined(CONFIG_S390) || defined(CONFIG_TILE) { .procname = "exception-trace", .data = &show_unhandled_signals, diff --git a/kernel/time/clockevents.c b/kernel/time/clockevents.c index c027d4f..e4c699d 100644 --- a/kernel/time/clockevents.c +++ b/kernel/time/clockevents.c @@ -182,7 +182,10 @@ void clockevents_register_device(struct clock_event_device *dev) unsigned long flags; BUG_ON(dev->mode != CLOCK_EVT_MODE_UNUSED); - BUG_ON(!dev->cpumask); + if (!dev->cpumask) { + WARN_ON(num_possible_cpus() > 1); + dev->cpumask = cpumask_of(smp_processor_id()); + } raw_spin_lock_irqsave(&clockevents_lock, flags); diff --git a/kernel/timer.c b/kernel/timer.c index fd61986..8cff361 100644 --- a/kernel/timer.c +++ b/kernel/timer.c @@ -749,16 +749,15 @@ unsigned long apply_slack(struct timer_list *timer, unsigned long expires) unsigned long expires_limit, mask; int bit; - expires_limit = expires; - if (timer->slack >= 0) { expires_limit = expires + timer->slack; } else { - unsigned long now = jiffies; + long delta = expires - jiffies; + + if (delta < 256) + return expires; - /* No slack, if already expired else auto slack 0.4% */ - if (time_after(expires, now)) - expires_limit = expires + (expires - now)/256; + expires_limit = expires + delta / 256; } mask = expires ^ expires_limit; if (mask == 0) @@ -795,6 +794,8 @@ unsigned long apply_slack(struct timer_list *timer, unsigned long expires) */ int mod_timer(struct timer_list *timer, unsigned long expires) { + expires = apply_slack(timer, expires); + /* * This is a common optimization triggered by the * networking code - if the timer is re-modified @@ -803,8 +804,6 @@ int mod_timer(struct timer_list *timer, unsigned long expires) if (timer_pending(timer) && timer->expires == expires) return 1; - expires = apply_slack(timer, expires); - return __mod_timer(timer, expires, false, TIMER_NOT_PINNED); } EXPORT_SYMBOL(mod_timer); diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index d017c2c..1ee417f 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -109,12 +109,18 @@ ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip); static void ftrace_global_list_func(unsigned long ip, unsigned long parent_ip) { - struct ftrace_ops *op = rcu_dereference_raw(ftrace_global_list); /*see above*/ + struct ftrace_ops *op; + + if (unlikely(trace_recursion_test(TRACE_GLOBAL_BIT))) + return; + trace_recursion_set(TRACE_GLOBAL_BIT); + op = rcu_dereference_raw(ftrace_global_list); /*see above*/ while (op != &ftrace_list_end) { op->func(ip, parent_ip); op = rcu_dereference_raw(op->next); /*see above*/ }; + trace_recursion_clear(TRACE_GLOBAL_BIT); } static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip) @@ -1638,12 +1644,12 @@ static void ftrace_startup_enable(int command) ftrace_run_update_code(command); } -static void ftrace_startup(struct ftrace_ops *ops, int command) +static int ftrace_startup(struct ftrace_ops *ops, int command) { bool hash_enable = true; if (unlikely(ftrace_disabled)) - return; + return -ENODEV; ftrace_start_up++; command |= FTRACE_ENABLE_CALLS; @@ -1662,6 +1668,8 @@ static void ftrace_startup(struct ftrace_ops *ops, int command) ftrace_hash_rec_enable(ops, 1); ftrace_startup_enable(command); + + return 0; } static void ftrace_shutdown(struct ftrace_ops *ops, int command) @@ -2501,7 +2509,7 @@ static void __enable_ftrace_function_probe(void) ret = __register_ftrace_function(&trace_probe_ops); if (!ret) - ftrace_startup(&trace_probe_ops, 0); + ret = ftrace_startup(&trace_probe_ops, 0); ftrace_probe_registered = 1; } @@ -3466,7 +3474,11 @@ device_initcall(ftrace_nodyn_init); static inline int ftrace_init_dyn_debugfs(struct dentry *d_tracer) { return 0; } static inline void ftrace_startup_enable(int command) { } /* Keep as macros so we do not need to define the commands */ -# define ftrace_startup(ops, command) do { } while (0) +# define ftrace_startup(ops, command) \ + ({ \ + (ops)->flags |= FTRACE_OPS_FL_ENABLED; \ + 0; \ + }) # define ftrace_shutdown(ops, command) do { } while (0) # define ftrace_startup_sysctl() do { } while (0) # define ftrace_shutdown_sysctl() do { } while (0) @@ -3484,6 +3496,10 @@ ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip) { struct ftrace_ops *op; + if (unlikely(trace_recursion_test(TRACE_INTERNAL_BIT))) + return; + + trace_recursion_set(TRACE_INTERNAL_BIT); /* * Some of the ops may be dynamically allocated, * they must be freed after a synchronize_sched(). @@ -3496,6 +3512,7 @@ ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip) op = rcu_dereference_raw(op->next); }; preempt_enable_notrace(); + trace_recursion_clear(TRACE_INTERNAL_BIT); } static void clear_ftrace_swapper(void) @@ -3799,7 +3816,7 @@ int register_ftrace_function(struct ftrace_ops *ops) ret = __register_ftrace_function(ops); if (!ret) - ftrace_startup(ops, 0); + ret = ftrace_startup(ops, 0); out_unlock: @@ -4045,7 +4062,7 @@ int register_ftrace_graph(trace_func_graph_ret_t retfunc, ftrace_graph_return = retfunc; ftrace_graph_entry = entryfunc; - ftrace_startup(&global_ops, FTRACE_START_FUNC_RET); + ret = ftrace_startup(&global_ops, FTRACE_START_FUNC_RET); out: mutex_unlock(&ftrace_lock); diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index 0ef7b4b..b0c7aa4 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -2216,7 +2216,7 @@ static noinline void trace_recursive_fail(void) printk_once(KERN_WARNING "Tracing recursion: depth[%ld]:" "HC[%lu]:SC[%lu]:NMI[%lu]\n", - current->trace_recursion, + trace_recursion_buffer(), hardirq_count() >> HARDIRQ_SHIFT, softirq_count() >> SOFTIRQ_SHIFT, in_nmi()); @@ -2226,9 +2226,9 @@ static noinline void trace_recursive_fail(void) static inline int trace_recursive_lock(void) { - current->trace_recursion++; + trace_recursion_inc(); - if (likely(current->trace_recursion < TRACE_RECURSIVE_DEPTH)) + if (likely(trace_recursion_buffer() < TRACE_RECURSIVE_DEPTH)) return 0; trace_recursive_fail(); @@ -2238,9 +2238,9 @@ static inline int trace_recursive_lock(void) static inline void trace_recursive_unlock(void) { - WARN_ON_ONCE(!current->trace_recursion); + WARN_ON_ONCE(!trace_recursion_buffer()); - current->trace_recursion--; + trace_recursion_dec(); } #else diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 6b69c4b..229f859 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -784,4 +784,19 @@ extern const char *__stop___trace_bprintk_fmt[]; FTRACE_ENTRY(call, struct_name, id, PARAMS(tstruct), PARAMS(print)) #include "trace_entries.h" +/* Only current can touch trace_recursion */ +#define trace_recursion_inc() do { (current)->trace_recursion++; } while (0) +#define trace_recursion_dec() do { (current)->trace_recursion--; } while (0) + +/* Ring buffer has the 10 LSB bits to count */ +#define trace_recursion_buffer() ((current)->trace_recursion & 0x3ff) + +/* for function tracing recursion */ +#define TRACE_INTERNAL_BIT (1<<11) +#define TRACE_GLOBAL_BIT (1<<12) + +#define trace_recursion_set(bit) do { (current)->trace_recursion |= (bit); } while (0) +#define trace_recursion_clear(bit) do { (current)->trace_recursion &= ~(bit); } while (0) +#define trace_recursion_test(bit) ((current)->trace_recursion & (bit)) + #endif /* _LINUX_KERNEL_TRACE_H */ diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index 2fe1103..686ec39 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -1657,7 +1657,12 @@ static struct ftrace_ops trace_ops __initdata = static __init void event_trace_self_test_with_function(void) { - register_ftrace_function(&trace_ops); + int ret; + ret = register_ftrace_function(&trace_ops); + if (WARN_ON(ret < 0)) { + pr_info("Failed to enable function tracer for event tests\n"); + return; + } pr_info("Running tests again, along with the function tracer\n"); event_trace_self_tests(); unregister_ftrace_function(&trace_ops); diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c index cf535cc..e37de492 100644 --- a/kernel/trace/trace_output.c +++ b/kernel/trace/trace_output.c @@ -353,6 +353,33 @@ ftrace_print_symbols_seq(struct trace_seq *p, unsigned long val, } EXPORT_SYMBOL(ftrace_print_symbols_seq); +#if BITS_PER_LONG == 32 +const char * +ftrace_print_symbols_seq_u64(struct trace_seq *p, unsigned long long val, + const struct trace_print_flags_u64 *symbol_array) +{ + int i; + const char *ret = p->buffer + p->len; + + for (i = 0; symbol_array[i].name; i++) { + + if (val != symbol_array[i].mask) + continue; + + trace_seq_puts(p, symbol_array[i].name); + break; + } + + if (!p->len) + trace_seq_printf(p, "0x%llx", val); + + trace_seq_putc(p, 0); + + return ret; +} +EXPORT_SYMBOL(ftrace_print_symbols_seq_u64); +#endif + const char * ftrace_print_hex_seq(struct trace_seq *p, const unsigned char *buf, int buf_len) { diff --git a/kernel/utsname.c b/kernel/utsname.c index 4464617..bff131b 100644 --- a/kernel/utsname.c +++ b/kernel/utsname.c @@ -15,6 +15,7 @@ #include <linux/err.h> #include <linux/slab.h> #include <linux/user_namespace.h> +#include <linux/proc_fs.h> static struct uts_namespace *create_uts_ns(void) { @@ -79,3 +80,41 @@ void free_uts_ns(struct kref *kref) put_user_ns(ns->user_ns); kfree(ns); } + +static void *utsns_get(struct task_struct *task) +{ + struct uts_namespace *ns = NULL; + struct nsproxy *nsproxy; + + rcu_read_lock(); + nsproxy = task_nsproxy(task); + if (nsproxy) { + ns = nsproxy->uts_ns; + get_uts_ns(ns); + } + rcu_read_unlock(); + + return ns; +} + +static void utsns_put(void *ns) +{ + put_uts_ns(ns); +} + +static int utsns_install(struct nsproxy *nsproxy, void *ns) +{ + get_uts_ns(ns); + put_uts_ns(nsproxy->uts_ns); + nsproxy->uts_ns = ns; + return 0; +} + +const struct proc_ns_operations utsns_operations = { + .name = "uts", + .type = CLONE_NEWUTS, + .get = utsns_get, + .put = utsns_put, + .install = utsns_install, +}; + diff --git a/kernel/watchdog.c b/kernel/watchdog.c index 7daa4b0..3d0c56a 100644 --- a/kernel/watchdog.c +++ b/kernel/watchdog.c @@ -415,15 +415,13 @@ static void watchdog_nmi_disable(int cpu) { return; } #endif /* CONFIG_HARDLOCKUP_DETECTOR */ /* prepare/enable/disable routines */ -static int watchdog_prepare_cpu(int cpu) +static void watchdog_prepare_cpu(int cpu) { struct hrtimer *hrtimer = &per_cpu(watchdog_hrtimer, cpu); WARN_ON(per_cpu(softlockup_watchdog, cpu)); hrtimer_init(hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); hrtimer->function = watchdog_timer_fn; - - return 0; } static int watchdog_enable(int cpu) @@ -542,17 +540,16 @@ static int __cpuinit cpu_callback(struct notifier_block *nfb, unsigned long action, void *hcpu) { int hotcpu = (unsigned long)hcpu; - int err = 0; switch (action) { case CPU_UP_PREPARE: case CPU_UP_PREPARE_FROZEN: - err = watchdog_prepare_cpu(hotcpu); + watchdog_prepare_cpu(hotcpu); break; case CPU_ONLINE: case CPU_ONLINE_FROZEN: if (watchdog_enabled) - err = watchdog_enable(hotcpu); + watchdog_enable(hotcpu); break; #ifdef CONFIG_HOTPLUG_CPU case CPU_UP_CANCELED: diff --git a/kernel/workqueue.c b/kernel/workqueue.c index e3378e8..0400553 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -2866,9 +2866,7 @@ static int alloc_cwqs(struct workqueue_struct *wq) } } - /* just in case, make sure it's actually aligned - * - this is affected by PERCPU() alignment in vmlinux.lds.S - */ + /* just in case, make sure it's actually aligned */ BUG_ON(!IS_ALIGNED(wq->cpu_wq.v, align)); return wq->cpu_wq.v ? 0 : -ENOMEM; } |
