rk3368: io-domain: add io domain volt sel

[firefly-linux-kernel-4.4.55.git] / kernel / fork.c

diff --git a/kernel/fork.c b/kernel/fork.c
index 514dbc40f98fcdd9adfac0f13f9a28e8ac55eacd..b0663950634b332526d3bd28074953e1369361c9 100644 (file)
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -198,6 +198,9 @@ struct kmem_cache *vm_area_cachep;
 /* SLAB cache for mm_struct structures (tsk->mm) */
 static struct kmem_cache *mm_cachep;
 
+/* Notifier list called when a task struct is freed */
+static ATOMIC_NOTIFIER_HEAD(task_free_notifier);
+
 static void account_kernel_stack(struct thread_info *ti, int account)
 {
        struct zone *zone = page_zone(virt_to_page(ti));
@@ -231,6 +234,18 @@ static inline void put_signal_struct(struct signal_struct *sig)
                free_signal_struct(sig);
 }
 
+int task_free_register(struct notifier_block *n)
+{
+       return atomic_notifier_chain_register(&task_free_notifier, n);
+}
+EXPORT_SYMBOL(task_free_register);
+
+int task_free_unregister(struct notifier_block *n)
+{
+       return atomic_notifier_chain_unregister(&task_free_notifier, n);
+}
+EXPORT_SYMBOL(task_free_unregister);
+
 void __put_task_struct(struct task_struct *tsk)
 {
        WARN_ON(!tsk->exit_state);
@@ -242,6 +257,7 @@ void __put_task_struct(struct task_struct *tsk)
        delayacct_tsk_free(tsk);
        put_signal_struct(tsk->signal);
 
+       atomic_notifier_call_chain(&task_free_notifier, 0, tsk);
        if (!profile_handoff_task(tsk))
                free_task(tsk);
 }
@@ -311,6 +327,15 @@ static struct task_struct *dup_task_struct(struct task_struct *orig)
                goto free_ti;
 
        tsk->stack = ti;
+#ifdef CONFIG_SECCOMP
+       /*
+        * We must handle setting up seccomp filters once we're under
+        * the sighand lock in case orig has changed between now and
+        * then. Until then, filter must be NULL to avoid messing up
+        * the usage counts on the error path calling free_task.
+        */
+       tsk->seccomp.filter = NULL;
+#endif
 
        setup_thread_stack(tsk, orig);
        clear_user_return_notifier(tsk);
@@ -697,7 +722,8 @@ struct mm_struct *mm_access(struct task_struct *task, unsigned int mode)
 
        mm = get_task_mm(task);
        if (mm && mm != current->mm &&
-                       !ptrace_may_access(task, mode)) {
+                       !ptrace_may_access(task, mode) &&
+                       !capable(CAP_SYS_RESOURCE)) {
                mmput(mm);
                mm = ERR_PTR(-EACCES);
        }
@@ -1091,6 +1117,39 @@ static void copy_flags(unsigned long clone_flags, struct task_struct *p)
        p->flags = new_flags;
 }
 
+static void copy_seccomp(struct task_struct *p)
+{
+#ifdef CONFIG_SECCOMP
+       /*
+        * Must be called with sighand->lock held, which is common to
+        * all threads in the group. Holding cred_guard_mutex is not
+        * needed because this new task is not yet running and cannot
+        * be racing exec.
+        */
+       assert_spin_locked(&current->sighand->siglock);
+
+       /* Ref-count the new filter user, and assign it. */
+       get_seccomp_filter(current);
+       p->seccomp = current->seccomp;
+
+       /*
+        * Explicitly enable no_new_privs here in case it got set
+        * between the task_struct being duplicated and holding the
+        * sighand lock. The seccomp state and nnp must be in sync.
+        */
+       if (task_no_new_privs(current))
+               task_set_no_new_privs(p);
+
+       /*
+        * If the parent gained a seccomp mode after copying thread
+        * flags and between before we held the sighand lock, we have
+        * to manually enable the seccomp thread flag here.
+        */
+       if (p->seccomp.mode != SECCOMP_MODE_DISABLED)
+               set_tsk_thread_flag(p, TIF_SECCOMP);
+#endif
+}
+
 SYSCALL_DEFINE1(set_tid_address, int __user *, tidptr)
 {
        current->clear_child_tid = tidptr;
@@ -1195,7 +1254,6 @@ static struct task_struct *copy_process(unsigned long clone_flags,
                goto fork_out;
 
        ftrace_graph_init_task(p);
-       get_seccomp_filter(p);
 
        rt_mutex_init_task(p);
 
@@ -1437,6 +1495,12 @@ static struct task_struct *copy_process(unsigned long clone_flags,
 
        spin_lock(&current->sighand->siglock);
 
+       /*
+        * Copy seccomp details explicitly here, in case they were changed
+        * before holding sighand lock.
+        */
+       copy_seccomp(p);
+
        /*
         * Process group and session signals need to be delivered to just the
         * parent before the fork or both the parent and the child after the