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Diffstat (limited to 'kernel/fork.c')
-rw-r--r--kernel/fork.c51
1 files changed, 31 insertions, 20 deletions
diff --git a/kernel/fork.c b/kernel/fork.c
index 4d57d9e3a6e9..b6cce14ba047 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -165,6 +165,18 @@ void free_task(struct task_struct *tsk)
}
EXPORT_SYMBOL(free_task);
+static inline void free_signal_struct(struct signal_struct *sig)
+{
+ taskstats_tgid_free(sig);
+ kmem_cache_free(signal_cachep, sig);
+}
+
+static inline void put_signal_struct(struct signal_struct *sig)
+{
+ if (atomic_dec_and_test(&sig->sigcnt))
+ free_signal_struct(sig);
+}
+
void __put_task_struct(struct task_struct *tsk)
{
WARN_ON(!tsk->exit_state);
@@ -173,6 +185,7 @@ void __put_task_struct(struct task_struct *tsk)
exit_creds(tsk);
delayacct_tsk_free(tsk);
+ put_signal_struct(tsk->signal);
if (!profile_handoff_task(tsk))
free_task(tsk);
@@ -864,8 +877,9 @@ static int copy_signal(unsigned long clone_flags, struct task_struct *tsk)
if (!sig)
return -ENOMEM;
- atomic_set(&sig->count, 1);
+ sig->nr_threads = 1;
atomic_set(&sig->live, 1);
+ atomic_set(&sig->sigcnt, 1);
init_waitqueue_head(&sig->wait_chldexit);
if (clone_flags & CLONE_NEWPID)
sig->flags |= SIGNAL_UNKILLABLE;
@@ -889,13 +903,6 @@ static int copy_signal(unsigned long clone_flags, struct task_struct *tsk)
return 0;
}
-void __cleanup_signal(struct signal_struct *sig)
-{
- thread_group_cputime_free(sig);
- tty_kref_put(sig->tty);
- kmem_cache_free(signal_cachep, sig);
-}
-
static void copy_flags(unsigned long clone_flags, struct task_struct *p)
{
unsigned long new_flags = p->flags;
@@ -1245,8 +1252,9 @@ static struct task_struct *copy_process(unsigned long clone_flags,
}
if (clone_flags & CLONE_THREAD) {
- atomic_inc(&current->signal->count);
+ current->signal->nr_threads++;
atomic_inc(&current->signal->live);
+ atomic_inc(&current->signal->sigcnt);
p->group_leader = current->group_leader;
list_add_tail_rcu(&p->thread_group, &p->group_leader->thread_group);
}
@@ -1259,7 +1267,6 @@ static struct task_struct *copy_process(unsigned long clone_flags,
p->nsproxy->pid_ns->child_reaper = p;
p->signal->leader_pid = pid;
- tty_kref_put(p->signal->tty);
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));
@@ -1292,7 +1299,7 @@ bad_fork_cleanup_mm:
mmput(p->mm);
bad_fork_cleanup_signal:
if (!(clone_flags & CLONE_THREAD))
- __cleanup_signal(p->signal);
+ free_signal_struct(p->signal);
bad_fork_cleanup_sighand:
__cleanup_sighand(p->sighand);
bad_fork_cleanup_fs:
@@ -1327,6 +1334,16 @@ noinline struct pt_regs * __cpuinit __attribute__((weak)) idle_regs(struct pt_re
return regs;
}
+static inline void init_idle_pids(struct pid_link *links)
+{
+ enum pid_type type;
+
+ for (type = PIDTYPE_PID; type < PIDTYPE_MAX; ++type) {
+ INIT_HLIST_NODE(&links[type].node); /* not really needed */
+ links[type].pid = &init_struct_pid;
+ }
+}
+
struct task_struct * __cpuinit fork_idle(int cpu)
{
struct task_struct *task;
@@ -1334,8 +1351,10 @@ struct task_struct * __cpuinit fork_idle(int cpu)
task = copy_process(CLONE_VM, 0, idle_regs(&regs), 0, NULL,
&init_struct_pid, 0);
- if (!IS_ERR(task))
+ if (!IS_ERR(task)) {
+ init_idle_pids(task->pids);
init_idle(task, cpu);
+ }
return task;
}
@@ -1507,14 +1526,6 @@ static void check_unshare_flags(unsigned long *flags_ptr)
*flags_ptr |= CLONE_SIGHAND;
/*
- * If unsharing signal handlers and the task was created
- * using CLONE_THREAD, then must unshare the thread
- */
- if ((*flags_ptr & CLONE_SIGHAND) &&
- (atomic_read(&current->signal->count) > 1))
- *flags_ptr |= CLONE_THREAD;
-
- /*
* If unsharing namespace, must also unshare filesystem information.
*/
if (*flags_ptr & CLONE_NEWNS)