]> pilppa.org Git - linux-2.6-omap-h63xx.git/blobdiff - kernel/fork.c
hwmon: (abituguru3) Cosmetic whitespace fixes
[linux-2.6-omap-h63xx.git] / kernel / fork.c
index b99d73e971a4f0f8f1e5c9d61654023e999bc8e1..f6083561dfe0a9f8d2a13138f7332bc358a51653 100644 (file)
@@ -27,6 +27,7 @@
 #include <linux/key.h>
 #include <linux/binfmts.h>
 #include <linux/mman.h>
+#include <linux/mmu_notifier.h>
 #include <linux/fs.h>
 #include <linux/nsproxy.h>
 #include <linux/capability.h>
@@ -37,6 +38,7 @@
 #include <linux/swap.h>
 #include <linux/syscalls.h>
 #include <linux/jiffies.h>
+#include <linux/tracehook.h>
 #include <linux/futex.h>
 #include <linux/task_io_accounting_ops.h>
 #include <linux/rcupdate.h>
@@ -56,6 +58,7 @@
 #include <linux/tty.h>
 #include <linux/proc_fs.h>
 #include <linux/blkdev.h>
+#include <trace/sched.h>
 
 #include <asm/pgtable.h>
 #include <asm/pgalloc.h>
@@ -413,6 +416,7 @@ static struct mm_struct * mm_init(struct mm_struct * mm, struct task_struct *p)
 
        if (likely(!mm_alloc_pgd(mm))) {
                mm->def_flags = 0;
+               mmu_notifier_mm_init(mm);
                return mm;
        }
 
@@ -445,6 +449,7 @@ void __mmdrop(struct mm_struct *mm)
        BUG_ON(mm == &init_mm);
        mm_free_pgd(mm);
        destroy_context(mm);
+       mmu_notifier_mm_destroy(mm);
        free_mm(mm);
 }
 EXPORT_SYMBOL_GPL(__mmdrop);
@@ -656,13 +661,6 @@ static struct fs_struct *__copy_fs_struct(struct fs_struct *old)
                path_get(&old->root);
                fs->pwd = old->pwd;
                path_get(&old->pwd);
-               if (old->altroot.dentry) {
-                       fs->altroot = old->altroot;
-                       path_get(&old->altroot);
-               } else {
-                       fs->altroot.mnt = NULL;
-                       fs->altroot.dentry = NULL;
-               }
                read_unlock(&old->lock);
        }
        return fs;
@@ -762,15 +760,44 @@ void __cleanup_sighand(struct sighand_struct *sighand)
                kmem_cache_free(sighand_cachep, sighand);
 }
 
+
+/*
+ * Initialize POSIX timer handling for a thread group.
+ */
+static void posix_cpu_timers_init_group(struct signal_struct *sig)
+{
+       /* Thread group counters. */
+       thread_group_cputime_init(sig);
+
+       /* Expiration times and increments. */
+       sig->it_virt_expires = cputime_zero;
+       sig->it_virt_incr = cputime_zero;
+       sig->it_prof_expires = cputime_zero;
+       sig->it_prof_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;
+
+       /* The timer lists. */
+       INIT_LIST_HEAD(&sig->cpu_timers[0]);
+       INIT_LIST_HEAD(&sig->cpu_timers[1]);
+       INIT_LIST_HEAD(&sig->cpu_timers[2]);
+}
+
 static int copy_signal(unsigned long clone_flags, struct task_struct *tsk)
 {
        struct signal_struct *sig;
        int ret;
 
        if (clone_flags & CLONE_THREAD) {
-               atomic_inc(&current->signal->count);
-               atomic_inc(&current->signal->live);
-               return 0;
+               ret = thread_group_cputime_clone_thread(current);
+               if (likely(!ret)) {
+                       atomic_inc(&current->signal->count);
+                       atomic_inc(&current->signal->live);
+               }
+               return ret;
        }
        sig = kmem_cache_alloc(signal_cachep, GFP_KERNEL);
        tsk->signal = sig;
@@ -798,44 +825,25 @@ static int copy_signal(unsigned long clone_flags, struct task_struct *tsk)
        sig->it_real_incr.tv64 = 0;
        sig->real_timer.function = it_real_fn;
 
-       sig->it_virt_expires = cputime_zero;
-       sig->it_virt_incr = cputime_zero;
-       sig->it_prof_expires = cputime_zero;
-       sig->it_prof_incr = cputime_zero;
-
        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->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;
-#ifdef CONFIG_TASK_XACCT
-       sig->rchar = sig->wchar = sig->syscr = sig->syscw = 0;
-#endif
-#ifdef CONFIG_TASK_IO_ACCOUNTING
-       memset(&sig->ioac, 0, sizeof(sig->ioac));
-#endif
-       sig->sum_sched_runtime = 0;
-       INIT_LIST_HEAD(&sig->cpu_timers[0]);
-       INIT_LIST_HEAD(&sig->cpu_timers[1]);
-       INIT_LIST_HEAD(&sig->cpu_timers[2]);
+       task_io_accounting_init(&sig->ioac);
        taskstats_tgid_init(sig);
 
        task_lock(current->group_leader);
        memcpy(sig->rlim, current->signal->rlim, sizeof sig->rlim);
        task_unlock(current->group_leader);
 
-       if (sig->rlim[RLIMIT_CPU].rlim_cur != RLIM_INFINITY) {
-               /*
-                * New sole thread in the process gets an expiry time
-                * of the whole CPU time limit.
-                */
-               tsk->it_prof_expires =
-                       secs_to_cputime(sig->rlim[RLIMIT_CPU].rlim_cur);
-       }
+       posix_cpu_timers_init_group(sig);
+
        acct_init_pacct(&sig->pacct);
 
        tty_audit_fork(sig);
@@ -845,7 +853,9 @@ static int copy_signal(unsigned long clone_flags, struct task_struct *tsk)
 
 void __cleanup_signal(struct signal_struct *sig)
 {
+       thread_group_cputime_free(sig);
        exit_thread_group_keys(sig);
+       tty_kref_put(sig->tty);
        kmem_cache_free(signal_cachep, sig);
 }
 
@@ -865,8 +875,7 @@ static void copy_flags(unsigned long clone_flags, struct task_struct *p)
 
        new_flags &= ~PF_SUPERPRIV;
        new_flags |= PF_FORKNOEXEC;
-       if (!(clone_flags & CLONE_PTRACE))
-               p->ptrace = 0;
+       new_flags |= PF_STARTING;
        p->flags = new_flags;
        clear_freeze_flag(p);
 }
@@ -894,6 +903,19 @@ void mm_init_owner(struct mm_struct *mm, struct task_struct *p)
 }
 #endif /* CONFIG_MM_OWNER */
 
+/*
+ * Initialize POSIX timer handling for a single task.
+ */
+static void posix_cpu_timers_init(struct task_struct *tsk)
+{
+       tsk->cputime_expires.prof_exp = cputime_zero;
+       tsk->cputime_expires.virt_exp = cputime_zero;
+       tsk->cputime_expires.sched_exp = 0;
+       INIT_LIST_HEAD(&tsk->cpu_timers[0]);
+       INIT_LIST_HEAD(&tsk->cpu_timers[1]);
+       INIT_LIST_HEAD(&tsk->cpu_timers[2]);
+}
+
 /*
  * This creates a new process as a copy of the old one,
  * but does not actually start it yet.
@@ -907,7 +929,8 @@ static struct task_struct *copy_process(unsigned long clone_flags,
                                        struct pt_regs *regs,
                                        unsigned long stack_size,
                                        int __user *child_tidptr,
-                                       struct pid *pid)
+                                       struct pid *pid,
+                                       int trace)
 {
        int retval;
        struct task_struct *p;
@@ -995,26 +1018,17 @@ static struct task_struct *copy_process(unsigned long clone_flags,
        p->prev_utime = cputime_zero;
        p->prev_stime = cputime_zero;
 
+       p->default_timer_slack_ns = current->timer_slack_ns;
+
 #ifdef CONFIG_DETECT_SOFTLOCKUP
        p->last_switch_count = 0;
        p->last_switch_timestamp = 0;
 #endif
 
-#ifdef CONFIG_TASK_XACCT
-       p->rchar = 0;           /* I/O counter: bytes read */
-       p->wchar = 0;           /* I/O counter: bytes written */
-       p->syscr = 0;           /* I/O counter: read syscalls */
-       p->syscw = 0;           /* I/O counter: write syscalls */
-#endif
-       task_io_accounting_init(p);
+       task_io_accounting_init(&p->ioac);
        acct_clear_integrals(p);
 
-       p->it_virt_expires = cputime_zero;
-       p->it_prof_expires = cputime_zero;
-       p->it_sched_expires = 0;
-       INIT_LIST_HEAD(&p->cpu_timers[0]);
-       INIT_LIST_HEAD(&p->cpu_timers[1]);
-       INIT_LIST_HEAD(&p->cpu_timers[2]);
+       posix_cpu_timers_init(p);
 
        p->lock_depth = -1;             /* -1 = no lock */
        do_posix_clock_monotonic_gettime(&p->start_time);
@@ -1163,8 +1177,6 @@ static struct task_struct *copy_process(unsigned long clone_flags,
         */
        p->group_leader = p;
        INIT_LIST_HEAD(&p->thread_group);
-       INIT_LIST_HEAD(&p->ptrace_entry);
-       INIT_LIST_HEAD(&p->ptraced);
 
        /* Now that the task is set up, run cgroup callbacks if
         * necessary. We need to run them before the task is visible
@@ -1195,7 +1207,6 @@ static struct task_struct *copy_process(unsigned long clone_flags,
                p->real_parent = current->real_parent;
        else
                p->real_parent = current;
-       p->parent = p->real_parent;
 
        spin_lock(&current->sighand->siglock);
 
@@ -1218,34 +1229,19 @@ static struct task_struct *copy_process(unsigned long clone_flags,
        if (clone_flags & CLONE_THREAD) {
                p->group_leader = current->group_leader;
                list_add_tail_rcu(&p->thread_group, &p->group_leader->thread_group);
-
-               if (!cputime_eq(current->signal->it_virt_expires,
-                               cputime_zero) ||
-                   !cputime_eq(current->signal->it_prof_expires,
-                               cputime_zero) ||
-                   current->signal->rlim[RLIMIT_CPU].rlim_cur != RLIM_INFINITY ||
-                   !list_empty(&current->signal->cpu_timers[0]) ||
-                   !list_empty(&current->signal->cpu_timers[1]) ||
-                   !list_empty(&current->signal->cpu_timers[2])) {
-                       /*
-                        * Have child wake up on its first tick to check
-                        * for process CPU timers.
-                        */
-                       p->it_prof_expires = jiffies_to_cputime(1);
-               }
        }
 
        if (likely(p->pid)) {
                list_add_tail(&p->sibling, &p->real_parent->children);
-               if (unlikely(p->ptrace & PT_PTRACED))
-                       __ptrace_link(p, current->parent);
+               tracehook_finish_clone(p, clone_flags, trace);
 
                if (thread_group_leader(p)) {
                        if (clone_flags & CLONE_NEWPID)
                                p->nsproxy->pid_ns->child_reaper = p;
 
                        p->signal->leader_pid = pid;
-                       p->signal->tty = current->signal->tty;
+                       tty_kref_put(p->signal->tty);
+                       p->signal->tty = tty_kref_get(current->signal->tty);
                        set_task_pgrp(p, task_pgrp_nr(current));
                        set_task_session(p, task_session_nr(current));
                        attach_pid(p, PIDTYPE_PGID, task_pgrp(current));
@@ -1323,29 +1319,13 @@ struct task_struct * __cpuinit fork_idle(int cpu)
        struct pt_regs regs;
 
        task = copy_process(CLONE_VM, 0, idle_regs(&regs), 0, NULL,
-                               &init_struct_pid);
+                           &init_struct_pid, 0);
        if (!IS_ERR(task))
                init_idle(task, cpu);
 
        return task;
 }
 
-static int fork_traceflag(unsigned clone_flags)
-{
-       if (clone_flags & CLONE_UNTRACED)
-               return 0;
-       else if (clone_flags & CLONE_VFORK) {
-               if (current->ptrace & PT_TRACE_VFORK)
-                       return PTRACE_EVENT_VFORK;
-       } else if ((clone_flags & CSIGNAL) != SIGCHLD) {
-               if (current->ptrace & PT_TRACE_CLONE)
-                       return PTRACE_EVENT_CLONE;
-       } else if (current->ptrace & PT_TRACE_FORK)
-               return PTRACE_EVENT_FORK;
-
-       return 0;
-}
-
 /*
  *  Ok, this is the main fork-routine.
  *
@@ -1380,14 +1360,14 @@ long do_fork(unsigned long clone_flags,
                }
        }
 
-       if (unlikely(current->ptrace)) {
-               trace = fork_traceflag (clone_flags);
-               if (trace)
-                       clone_flags |= CLONE_PTRACE;
-       }
+       /*
+        * When called from kernel_thread, don't do user tracing stuff.
+        */
+       if (likely(user_mode(regs)))
+               trace = tracehook_prepare_clone(clone_flags);
 
        p = copy_process(clone_flags, stack_start, regs, stack_size,
-                       child_tidptr, NULL);
+                        child_tidptr, NULL, trace);
        /*
         * Do this prior waking up the new thread - the thread pointer
         * might get invalid after that point, if the thread exits quickly.
@@ -1395,6 +1375,8 @@ long do_fork(unsigned long clone_flags,
        if (!IS_ERR(p)) {
                struct completion vfork;
 
+               trace_sched_process_fork(current, p);
+
                nr = task_pid_vnr(p);
 
                if (clone_flags & CLONE_PARENT_SETTID)
@@ -1405,32 +1387,35 @@ long do_fork(unsigned long clone_flags,
                        init_completion(&vfork);
                }
 
-               if ((p->ptrace & PT_PTRACED) || (clone_flags & CLONE_STOPPED)) {
+               tracehook_report_clone(trace, regs, clone_flags, nr, p);
+
+               /*
+                * We set PF_STARTING at creation in case tracing wants to
+                * use this to distinguish a fully live task from one that
+                * hasn't gotten to tracehook_report_clone() yet.  Now we
+                * clear it and set the child going.
+                */
+               p->flags &= ~PF_STARTING;
+
+               if (unlikely(clone_flags & CLONE_STOPPED)) {
                        /*
                         * We'll start up with an immediate SIGSTOP.
                         */
                        sigaddset(&p->pending.signal, SIGSTOP);
                        set_tsk_thread_flag(p, TIF_SIGPENDING);
-               }
-
-               if (!(clone_flags & CLONE_STOPPED))
-                       wake_up_new_task(p, clone_flags);
-               else
                        __set_task_state(p, TASK_STOPPED);
-
-               if (unlikely (trace)) {
-                       current->ptrace_message = nr;
-                       ptrace_notify ((trace << 8) | SIGTRAP);
+               } else {
+                       wake_up_new_task(p, clone_flags);
                }
 
+               tracehook_report_clone_complete(trace, regs,
+                                               clone_flags, nr, p);
+
                if (clone_flags & CLONE_VFORK) {
                        freezer_do_not_count();
                        wait_for_completion(&vfork);
                        freezer_count();
-                       if (unlikely (current->ptrace & PT_TRACE_VFORK_DONE)) {
-                               current->ptrace_message = nr;
-                               ptrace_notify ((PTRACE_EVENT_VFORK_DONE << 8) | SIGTRAP);
-                       }
+                       tracehook_report_vfork_done(p, nr);
                }
        } else {
                nr = PTR_ERR(p);
@@ -1442,7 +1427,7 @@ long do_fork(unsigned long clone_flags,
 #define ARCH_MIN_MMSTRUCT_ALIGN 0
 #endif
 
-static void sighand_ctor(struct kmem_cache *cachep, void *data)
+static void sighand_ctor(void *data)
 {
        struct sighand_struct *sighand = data;