ALSA: usb-audio: add support for Akai MPD16
[safe/jmp/linux-2.6] / kernel / fork.c
index 166b8c4..4d57d9e 100644 (file)
@@ -64,6 +64,7 @@
 #include <linux/magic.h>
 #include <linux/perf_event.h>
 #include <linux/posix-timers.h>
+#include <linux/user-return-notifier.h>
 
 #include <asm/pgtable.h>
 #include <asm/pgalloc.h>
@@ -86,6 +87,14 @@ DEFINE_PER_CPU(unsigned long, process_counts) = 0;
 
 __cacheline_aligned DEFINE_RWLOCK(tasklist_lock);  /* outer */
 
+#ifdef CONFIG_PROVE_RCU
+int lockdep_tasklist_lock_is_held(void)
+{
+       return lockdep_is_held(&tasklist_lock);
+}
+EXPORT_SYMBOL_GPL(lockdep_tasklist_lock_is_held);
+#endif /* #ifdef CONFIG_PROVE_RCU */
+
 int nr_processes(void)
 {
        int cpu;
@@ -249,6 +258,7 @@ static struct task_struct *dup_task_struct(struct task_struct *orig)
                goto out;
 
        setup_thread_stack(tsk, orig);
+       clear_user_return_notifier(tsk);
        stackend = end_of_stack(tsk);
        *stackend = STACK_END_MAGIC;    /* for overflow detection */
 
@@ -326,15 +336,17 @@ static int dup_mmap(struct mm_struct *mm, struct mm_struct *oldmm)
                if (!tmp)
                        goto fail_nomem;
                *tmp = *mpnt;
+               INIT_LIST_HEAD(&tmp->anon_vma_chain);
                pol = mpol_dup(vma_policy(mpnt));
                retval = PTR_ERR(pol);
                if (IS_ERR(pol))
                        goto fail_nomem_policy;
                vma_set_policy(tmp, pol);
+               if (anon_vma_fork(tmp, mpnt))
+                       goto fail_nomem_anon_vma_fork;
                tmp->vm_flags &= ~VM_LOCKED;
                tmp->vm_mm = mm;
                tmp->vm_next = NULL;
-               anon_vma_link(tmp);
                file = tmp->vm_file;
                if (file) {
                        struct inode *inode = file->f_path.dentry->d_inode;
@@ -389,6 +401,8 @@ out:
        flush_tlb_mm(oldmm);
        up_write(&oldmm->mmap_sem);
        return retval;
+fail_nomem_anon_vma_fork:
+       mpol_put(pol);
 fail_nomem_policy:
        kmem_cache_free(vm_area_cachep, tmp);
 fail_nomem:
@@ -452,8 +466,7 @@ static struct mm_struct * mm_init(struct mm_struct * mm, struct task_struct *p)
                (current->mm->flags & MMF_INIT_MASK) : default_dump_filter;
        mm->core_state = NULL;
        mm->nr_ptes = 0;
-       set_mm_counter(mm, file_rss, 0);
-       set_mm_counter(mm, anon_rss, 0);
+       memset(&mm->rss_stat, 0, sizeof(mm->rss_stat));
        spin_lock_init(&mm->page_table_lock);
        mm->free_area_cache = TASK_UNMAPPED_BASE;
        mm->cached_hole_size = ~0UL;
@@ -822,23 +835,14 @@ void __cleanup_sighand(struct sighand_struct *sighand)
  */
 static void posix_cpu_timers_init_group(struct signal_struct *sig)
 {
+       unsigned long cpu_limit;
+
        /* Thread group counters. */
        thread_group_cputime_init(sig);
 
-       /* Expiration times and increments. */
-       sig->it[CPUCLOCK_PROF].expires = cputime_zero;
-       sig->it[CPUCLOCK_PROF].incr = cputime_zero;
-       sig->it[CPUCLOCK_VIRT].expires = cputime_zero;
-       sig->it[CPUCLOCK_VIRT].incr = cputime_zero;
-
-       /* Cached expiration times. */
-       sig->cputime_expires.prof_exp = cputime_zero;
-       sig->cputime_expires.virt_exp = cputime_zero;
-       sig->cputime_expires.sched_exp = 0;
-
-       if (sig->rlim[RLIMIT_CPU].rlim_cur != RLIM_INFINITY) {
-               sig->cputime_expires.prof_exp =
-                       secs_to_cputime(sig->rlim[RLIMIT_CPU].rlim_cur);
+       cpu_limit = ACCESS_ONCE(sig->rlim[RLIMIT_CPU].rlim_cur);
+       if (cpu_limit != RLIM_INFINITY) {
+               sig->cputime_expires.prof_exp = secs_to_cputime(cpu_limit);
                sig->cputimer.running = 1;
        }
 
@@ -855,7 +859,7 @@ static int copy_signal(unsigned long clone_flags, struct task_struct *tsk)
        if (clone_flags & CLONE_THREAD)
                return 0;
 
-       sig = kmem_cache_alloc(signal_cachep, GFP_KERNEL);
+       sig = kmem_cache_zalloc(signal_cachep, GFP_KERNEL);
        tsk->signal = sig;
        if (!sig)
                return -ENOMEM;
@@ -863,43 +867,21 @@ static int copy_signal(unsigned long clone_flags, struct task_struct *tsk)
        atomic_set(&sig->count, 1);
        atomic_set(&sig->live, 1);
        init_waitqueue_head(&sig->wait_chldexit);
-       sig->flags = 0;
        if (clone_flags & CLONE_NEWPID)
                sig->flags |= SIGNAL_UNKILLABLE;
-       sig->group_exit_code = 0;
-       sig->group_exit_task = NULL;
-       sig->group_stop_count = 0;
        sig->curr_target = tsk;
        init_sigpending(&sig->shared_pending);
        INIT_LIST_HEAD(&sig->posix_timers);
 
        hrtimer_init(&sig->real_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
-       sig->it_real_incr.tv64 = 0;
        sig->real_timer.function = it_real_fn;
 
-       sig->leader = 0;        /* session leadership doesn't inherit */
-       sig->tty_old_pgrp = NULL;
-       sig->tty = NULL;
-
-       sig->utime = sig->stime = sig->cutime = sig->cstime = cputime_zero;
-       sig->gtime = cputime_zero;
-       sig->cgtime = cputime_zero;
-       sig->nvcsw = sig->nivcsw = sig->cnvcsw = sig->cnivcsw = 0;
-       sig->min_flt = sig->maj_flt = sig->cmin_flt = sig->cmaj_flt = 0;
-       sig->inblock = sig->oublock = sig->cinblock = sig->coublock = 0;
-       sig->maxrss = sig->cmaxrss = 0;
-       task_io_accounting_init(&sig->ioac);
-       sig->sum_sched_runtime = 0;
-       taskstats_tgid_init(sig);
-
        task_lock(current->group_leader);
        memcpy(sig->rlim, current->signal->rlim, sizeof sig->rlim);
        task_unlock(current->group_leader);
 
        posix_cpu_timers_init_group(sig);
 
-       acct_init_pacct(&sig->pacct);
-
        tty_audit_fork(sig);
 
        sig->oom_adj = current->signal->oom_adj;
@@ -934,9 +916,9 @@ SYSCALL_DEFINE1(set_tid_address, int __user *, tidptr)
 
 static void rt_mutex_init_task(struct task_struct *p)
 {
-       spin_lock_init(&p->pi_lock);
+       raw_spin_lock_init(&p->pi_lock);
 #ifdef CONFIG_RT_MUTEXES
-       plist_head_init(&p->pi_waiters, &p->pi_lock);
+       plist_head_init_raw(&p->pi_waiters, &p->pi_lock);
        p->pi_blocked_on = NULL;
 #endif
 }
@@ -1028,7 +1010,7 @@ static struct task_struct *copy_process(unsigned long clone_flags,
 #endif
        retval = -EAGAIN;
        if (atomic_read(&p->real_cred->user->processes) >=
-                       p->signal->rlim[RLIMIT_NPROC].rlim_cur) {
+                       task_rlimit(p, RLIMIT_NPROC)) {
                if (!capable(CAP_SYS_ADMIN) && !capable(CAP_SYS_RESOURCE) &&
                    p->real_cred->user != INIT_USER)
                        goto bad_fork_free;
@@ -1066,8 +1048,13 @@ static struct task_struct *copy_process(unsigned long clone_flags,
        p->gtime = cputime_zero;
        p->utimescaled = cputime_zero;
        p->stimescaled = cputime_zero;
+#ifndef CONFIG_VIRT_CPU_ACCOUNTING
        p->prev_utime = cputime_zero;
        p->prev_stime = cputime_zero;
+#endif
+#if defined(SPLIT_RSS_COUNTING)
+       memset(&p->rss_stat, 0, sizeof(p->rss_stat));
+#endif
 
        p->default_timer_slack_ns = current->timer_slack_ns;
 
@@ -1120,10 +1107,10 @@ static struct task_struct *copy_process(unsigned long clone_flags,
 #ifdef CONFIG_DEBUG_MUTEXES
        p->blocked_on = NULL; /* not blocked yet */
 #endif
-
-       p->bts = NULL;
-
-       p->stack_start = stack_start;
+#ifdef CONFIG_CGROUP_MEM_RES_CTLR
+       p->memcg_batch.do_batch = 0;
+       p->memcg_batch.memcg = NULL;
+#endif
 
        /* Perform scheduler related setup. Assign this task to a CPU. */
        sched_fork(p, clone_flags);
@@ -1199,9 +1186,10 @@ static struct task_struct *copy_process(unsigned long clone_flags,
                p->sas_ss_sp = p->sas_ss_size = 0;
 
        /*
-        * Syscall tracing should be turned off in the child regardless
-        * of CLONE_PTRACE.
+        * Syscall tracing and stepping should be turned off in the
+        * child regardless of CLONE_PTRACE.
         */
+       user_disable_single_step(p);
        clear_tsk_thread_flag(p, TIF_SYSCALL_TRACE);
 #ifdef TIF_SYSCALL_EMU
        clear_tsk_thread_flag(p, TIF_SYSCALL_EMU);
@@ -1229,21 +1217,6 @@ static struct task_struct *copy_process(unsigned long clone_flags,
        /* Need tasklist lock for parent etc handling! */
        write_lock_irq(&tasklist_lock);
 
-       /*
-        * The task hasn't been attached yet, so its cpus_allowed mask will
-        * not be changed, nor will its assigned CPU.
-        *
-        * The cpus_allowed mask of the parent may have changed after it was
-        * copied first time - so re-copy it here, then check the child's CPU
-        * to ensure it is on a valid CPU (and if not, just force it back to
-        * parent's CPU). This avoids alot of nasty races.
-        */
-       p->cpus_allowed = current->cpus_allowed;
-       p->rt.nr_cpus_allowed = current->rt.nr_cpus_allowed;
-       if (unlikely(!cpu_isset(task_cpu(p), p->cpus_allowed) ||
-                       !cpu_online(task_cpu(p))))
-               set_task_cpu(p, smp_processor_id());
-
        /* CLONE_PARENT re-uses the old parent */
        if (clone_flags & (CLONE_PARENT|CLONE_THREAD)) {
                p->real_parent = current->real_parent;
@@ -1279,7 +1252,6 @@ static struct task_struct *copy_process(unsigned long clone_flags,
        }
 
        if (likely(p->pid)) {
-               list_add_tail(&p->sibling, &p->real_parent->children);
                tracehook_finish_clone(p, clone_flags, trace);
 
                if (thread_group_leader(p)) {
@@ -1291,6 +1263,7 @@ static struct task_struct *copy_process(unsigned long clone_flags,
                        p->signal->tty = tty_kref_get(current->signal->tty);
                        attach_pid(p, PIDTYPE_PGID, task_pgrp(current));
                        attach_pid(p, PIDTYPE_SID, task_session(current));
+                       list_add_tail(&p->sibling, &p->real_parent->children);
                        list_add_tail_rcu(&p->tasks, &init_task.tasks);
                        __get_cpu_var(process_counts)++;
                }
@@ -1310,7 +1283,8 @@ bad_fork_free_pid:
        if (pid != &init_struct_pid)
                free_pid(pid);
 bad_fork_cleanup_io:
-       put_io_context(p->io_context);
+       if (p->io_context)
+               exit_io_context(p);
 bad_fork_cleanup_namespaces:
        exit_task_namespaces(p);
 bad_fork_cleanup_mm: