X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=kernel%2Fexit.c;h=019a2843bf958e6727f19c9b30ceb4b0da8e7cb9;hb=0d2daf5cc858bd9305bae187310a1dabaad0a2db;hp=3f45e3cf931d917fc1dca145be32618afda895cd;hpb=96200591a34f8ecb98481c626125df43a2463b55;p=safe%2Fjmp%2Flinux-2.6 diff --git a/kernel/exit.c b/kernel/exit.c index 3f45e3c..019a284 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -55,7 +55,6 @@ #include #include #include -#include "cred-internals.h" static void exit_mm(struct task_struct * tsk); @@ -68,10 +67,10 @@ static void __unhash_process(struct task_struct *p) detach_pid(p, PIDTYPE_SID); list_del_rcu(&p->tasks); + list_del_init(&p->sibling); __get_cpu_var(process_counts)--; } list_del_rcu(&p->thread_group); - list_del_init(&p->sibling); } /* @@ -85,7 +84,9 @@ static void __exit_signal(struct task_struct *tsk) BUG_ON(!sig); BUG_ON(!atomic_read(&sig->count)); - sighand = rcu_dereference(tsk->sighand); + sighand = rcu_dereference_check(tsk->sighand, + rcu_read_lock_held() || + lockdep_tasklist_lock_is_held()); spin_lock(&sighand->siglock); posix_cpu_timers_exit(tsk); @@ -111,9 +112,9 @@ static void __exit_signal(struct task_struct *tsk) * We won't ever get here for the group leader, since it * will have been the last reference on the signal_struct. */ - sig->utime = cputime_add(sig->utime, task_utime(tsk)); - sig->stime = cputime_add(sig->stime, task_stime(tsk)); - sig->gtime = cputime_add(sig->gtime, task_gtime(tsk)); + sig->utime = cputime_add(sig->utime, tsk->utime); + sig->stime = cputime_add(sig->stime, tsk->stime); + sig->gtime = cputime_add(sig->gtime, tsk->gtime); sig->min_flt += tsk->min_flt; sig->maj_flt += tsk->maj_flt; sig->nvcsw += tsk->nvcsw; @@ -170,8 +171,10 @@ void release_task(struct task_struct * p) repeat: tracehook_prepare_release_task(p); /* don't need to get the RCU readlock here - the process is dead and - * can't be modifying its own credentials */ + * can't be modifying its own credentials. But shut RCU-lockdep up */ + rcu_read_lock(); atomic_dec(&__task_cred(p)->user->processes); + rcu_read_unlock(); proc_flush_task(p); @@ -473,9 +476,11 @@ static void close_files(struct files_struct * files) /* * It is safe to dereference the fd table without RCU or * ->file_lock because this is the last reference to the - * files structure. + * files structure. But use RCU to shut RCU-lockdep up. */ + rcu_read_lock(); fdt = files_fdtable(files); + rcu_read_unlock(); for (;;) { unsigned long set; i = j * __NFDBITS; @@ -521,10 +526,12 @@ void put_files_struct(struct files_struct *files) * at the end of the RCU grace period. Otherwise, * you can free files immediately. */ + rcu_read_lock(); fdt = files_fdtable(files); if (fdt != &files->fdtab) kmem_cache_free(files_cachep, files); free_fdtable(fdt); + rcu_read_unlock(); } } @@ -736,12 +743,9 @@ static struct task_struct *find_new_reaper(struct task_struct *father) /* * Any that need to be release_task'd are put on the @dead list. */ -static void reparent_thread(struct task_struct *father, struct task_struct *p, +static void reparent_leader(struct task_struct *father, struct task_struct *p, struct list_head *dead) { - if (p->pdeath_signal) - group_send_sig_info(p->pdeath_signal, SEND_SIG_NOINFO, p); - list_move_tail(&p->sibling, &p->real_parent->children); if (task_detached(p)) @@ -780,12 +784,18 @@ static void forget_original_parent(struct task_struct *father) reaper = find_new_reaper(father); list_for_each_entry_safe(p, n, &father->children, sibling) { - p->real_parent = reaper; - if (p->parent == father) { - BUG_ON(task_ptrace(p)); - p->parent = p->real_parent; - } - reparent_thread(father, p, &dead_children); + struct task_struct *t = p; + do { + t->real_parent = reaper; + if (t->parent == father) { + BUG_ON(task_ptrace(t)); + t->parent = t->real_parent; + } + if (t->pdeath_signal) + group_send_sig_info(t->pdeath_signal, + SEND_SIG_NOINFO, t); + } while_each_thread(p, t); + reparent_leader(father, p, &dead_children); } write_unlock_irq(&tasklist_lock); @@ -933,7 +943,7 @@ NORET_TYPE void do_exit(long code) * an exiting task cleaning up the robust pi futexes. */ smp_mb(); - spin_unlock_wait(&tsk->pi_lock); + raw_spin_unlock_wait(&tsk->pi_lock); if (unlikely(in_atomic())) printk(KERN_INFO "note: %s[%d] exited with preempt_count %d\n", @@ -941,7 +951,9 @@ NORET_TYPE void do_exit(long code) preempt_count()); acct_update_integrals(tsk); - + /* sync mm's RSS info before statistics gathering */ + if (tsk->mm) + sync_mm_rss(tsk, tsk->mm); group_dead = atomic_dec_and_test(&tsk->signal->live); if (group_dead) { hrtimer_cancel(&tsk->signal->real_timer); @@ -971,7 +983,7 @@ NORET_TYPE void do_exit(long code) exit_thread(); cgroup_exit(tsk, 1); - if (group_dead && tsk->signal->leader) + if (group_dead) disassociate_ctty(1); module_put(task_thread_info(tsk)->exec_domain->module); @@ -990,8 +1002,10 @@ NORET_TYPE void do_exit(long code) exit_notify(tsk, group_dead); #ifdef CONFIG_NUMA + task_lock(tsk); mpol_put(tsk->mempolicy); tsk->mempolicy = NULL; + task_unlock(tsk); #endif #ifdef CONFIG_FUTEX if (unlikely(current->pi_state_cache)) @@ -1009,7 +1023,7 @@ NORET_TYPE void do_exit(long code) tsk->flags |= PF_EXITPIDONE; if (tsk->io_context) - exit_io_context(); + exit_io_context(tsk); if (tsk->splice_pipe) __free_pipe_info(tsk->splice_pipe); @@ -1177,7 +1191,7 @@ static int wait_task_zombie(struct wait_opts *wo, struct task_struct *p) if (unlikely(wo->wo_flags & WNOWAIT)) { int exit_code = p->exit_code; - int why, status; + int why; get_task_struct(p); read_unlock(&tasklist_lock); @@ -1210,6 +1224,7 @@ static int wait_task_zombie(struct wait_opts *wo, struct task_struct *p) struct signal_struct *psig; struct signal_struct *sig; unsigned long maxrss; + cputime_t tgutime, tgstime; /* * The resource counters for the group leader are in its @@ -1225,20 +1240,23 @@ static int wait_task_zombie(struct wait_opts *wo, struct task_struct *p) * need to protect the access to parent->signal fields, * as other threads in the parent group can be right * here reaping other children at the same time. + * + * We use thread_group_times() to get times for the thread + * group, which consolidates times for all threads in the + * group including the group leader. */ + thread_group_times(p, &tgutime, &tgstime); spin_lock_irq(&p->real_parent->sighand->siglock); psig = p->real_parent->signal; sig = p->signal; psig->cutime = cputime_add(psig->cutime, - cputime_add(p->utime, - cputime_add(sig->utime, - sig->cutime))); + cputime_add(tgutime, + sig->cutime)); psig->cstime = cputime_add(psig->cstime, - cputime_add(p->stime, - cputime_add(sig->stime, - sig->cstime))); + cputime_add(tgstime, + sig->cstime)); psig->cgtime = cputime_add(psig->cgtime, cputime_add(p->gtime, @@ -1547,14 +1565,9 @@ static int do_wait_thread(struct wait_opts *wo, struct task_struct *tsk) struct task_struct *p; list_for_each_entry(p, &tsk->children, sibling) { - /* - * Do not consider detached threads. - */ - if (!task_detached(p)) { - int ret = wait_consider_task(wo, 0, p); - if (ret) - return ret; - } + int ret = wait_consider_task(wo, 0, p); + if (ret) + return ret; } return 0;