rcu: Permit call_rcu() from CPU_DYING notifiers

[linux-flexiantxendom0-3.2.10.git] / kernel / fork.c

diff --git a/kernel/fork.c b/kernel/fork.c
index 44b0e21..b9372a0 100644 (file)
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -193,6 +193,7 @@ void __put_task_struct(struct task_struct *tsk)
        WARN_ON(atomic_read(&tsk->usage));
        WARN_ON(tsk == current);
 
+       security_task_free(tsk);
        exit_creds(tsk);
        delayacct_tsk_free(tsk);
        put_signal_struct(tsk->signal);
@@ -355,7 +356,7 @@ static int dup_mmap(struct mm_struct *mm, struct mm_struct *oldmm)
                charge = 0;
                if (mpnt->vm_flags & VM_ACCOUNT) {
                        unsigned int len = (mpnt->vm_end - mpnt->vm_start) >> PAGE_SHIFT;
-                       if (security_vm_enough_memory(len))
+                       if (security_vm_enough_memory_mm(oldmm, len)) /* sic */
                                goto fail_nomem;
                        charge = len;
                }
@@ -511,6 +512,23 @@ static struct mm_struct *mm_init(struct mm_struct *mm, struct task_struct *p)
        return NULL;
 }
 
+static void check_mm(struct mm_struct *mm)
+{
+       int i;
+
+       for (i = 0; i < NR_MM_COUNTERS; i++) {
+               long x = atomic_long_read(&mm->rss_stat.count[i]);
+
+               if (unlikely(x))
+                       printk(KERN_ALERT "BUG: Bad rss-counter state "
+                                         "mm:%p idx:%d val:%ld\n", mm, i, x);
+       }
+
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+       VM_BUG_ON(mm->pmd_huge_pte);
+#endif
+}
+
 /*
  * Allocate and initialize an mm_struct.
  */
@@ -538,9 +556,7 @@ void __mmdrop(struct mm_struct *mm)
        mm_free_pgd(mm);
        destroy_context(mm);
        mmu_notifier_mm_destroy(mm);
-#ifdef CONFIG_TRANSPARENT_HUGEPAGE
-       VM_BUG_ON(mm->pmd_huge_pte);
-#endif
+       check_mm(mm);
        free_mm(mm);
 }
 EXPORT_SYMBOL_GPL(__mmdrop);
@@ -1035,6 +1051,9 @@ static int copy_signal(unsigned long clone_flags, struct task_struct *tsk)
        sig->oom_score_adj = current->signal->oom_score_adj;
        sig->oom_score_adj_min = current->signal->oom_score_adj_min;
 
+       sig->has_child_subreaper = current->signal->has_child_subreaper ||
+                                  current->signal->is_child_subreaper;
+
        mutex_init(&sig->cred_guard_mutex);
 
        return 0;
@@ -1046,7 +1065,6 @@ static void copy_flags(unsigned long clone_flags, struct task_struct *p)
 
        new_flags &= ~(PF_SUPERPRIV | PF_WQ_WORKER);
        new_flags |= PF_FORKNOEXEC;
-       new_flags |= PF_STARTING;
        p->flags = new_flags;
 }
 
@@ -1223,6 +1241,7 @@ static struct task_struct *copy_process(unsigned long clone_flags,
 #ifdef CONFIG_CPUSETS
        p->cpuset_mem_spread_rotor = NUMA_NO_NODE;
        p->cpuset_slab_spread_rotor = NUMA_NO_NODE;
+       seqcount_init(&p->mems_allowed_seq);
 #endif
 #ifdef CONFIG_TRACE_IRQFLAGS
        p->irq_events = 0;
@@ -1341,7 +1360,13 @@ static struct task_struct *copy_process(unsigned long clone_flags,
        clear_all_latency_tracing(p);
 
        /* ok, now we should be set up.. */
-       p->exit_signal = (clone_flags & CLONE_THREAD) ? -1 : (clone_flags & CSIGNAL);
+       if (clone_flags & CLONE_THREAD)
+               p->exit_signal = -1;
+       else if (clone_flags & CLONE_PARENT)
+               p->exit_signal = current->group_leader->exit_signal;
+       else
+               p->exit_signal = (clone_flags & CSIGNAL);
+
        p->pdeath_signal = 0;
        p->exit_state = 0;
 
@@ -1579,14 +1604,6 @@ long do_fork(unsigned long clone_flags,
                        get_task_struct(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 finished SIGSTOP raising yet.  Now we clear it
-                * and set the child going.
-                */
-               p->flags &= ~PF_STARTING;
-
                wake_up_new_task(p);
 
                /* forking complete and child started to run, tell ptracer */