check_unshare_flags: kill the bogus CLONE_SIGHAND/sig->count check

[pandora-kernel.git] / kernel / fork.c

diff --git a/kernel/fork.c b/kernel/fork.c
index 4d57d9e..40cd099 100644 (file)
--- 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);
@@ -864,6 +877,7 @@ static int copy_signal(unsigned long clone_flags, struct task_struct *tsk)
        if (!sig)
                return -ENOMEM;
 
+       atomic_set(&sig->sigcnt, 1);
        atomic_set(&sig->count, 1);
        atomic_set(&sig->live, 1);
        init_waitqueue_head(&sig->wait_chldexit);
@@ -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;
@@ -1079,6 +1086,10 @@ static struct task_struct *copy_process(unsigned long clone_flags,
        }
        mpol_fix_fork_child_flag(p);
 #endif
+#ifdef CONFIG_CPUSETS
+       p->cpuset_mem_spread_rotor = node_random(p->mems_allowed);
+       p->cpuset_slab_spread_rotor = node_random(p->mems_allowed);
+#endif
 #ifdef CONFIG_TRACE_IRQFLAGS
        p->irq_events = 0;
 #ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW
@@ -1245,6 +1256,7 @@ static struct task_struct *copy_process(unsigned long clone_flags,
        }
 
        if (clone_flags & CLONE_THREAD) {
+               atomic_inc(&current->signal->sigcnt);
                atomic_inc(&current->signal->count);
                atomic_inc(&current->signal->live);
                p->group_leader = current->group_leader;
@@ -1259,7 +1271,6 @@ 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 +1303,7 @@ 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:
@@ -1506,14 +1517,6 @@ static void check_unshare_flags(unsigned long *flags_ptr)
        if (*flags_ptr & CLONE_VM)
                *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.
         */