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Diffstat (limited to 'kernel/fork.c')
-rw-r--r--kernel/fork.c34
1 files changed, 26 insertions, 8 deletions
diff --git a/kernel/fork.c b/kernel/fork.c
index 51ad0b0b726..266c6af6ef1 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -434,6 +434,14 @@ __setup("coredump_filter=", coredump_filter_setup);
#include <linux/init_task.h>
+static void mm_init_aio(struct mm_struct *mm)
+{
+#ifdef CONFIG_AIO
+ spin_lock_init(&mm->ioctx_lock);
+ INIT_HLIST_HEAD(&mm->ioctx_list);
+#endif
+}
+
static struct mm_struct * mm_init(struct mm_struct * mm, struct task_struct *p)
{
atomic_set(&mm->mm_users, 1);
@@ -447,10 +455,9 @@ static struct mm_struct * mm_init(struct mm_struct * mm, struct task_struct *p)
set_mm_counter(mm, file_rss, 0);
set_mm_counter(mm, anon_rss, 0);
spin_lock_init(&mm->page_table_lock);
- spin_lock_init(&mm->ioctx_lock);
- INIT_HLIST_HEAD(&mm->ioctx_list);
mm->free_area_cache = TASK_UNMAPPED_BASE;
mm->cached_hole_size = ~0UL;
+ mm_init_aio(mm);
mm_init_owner(mm, p);
if (likely(!mm_alloc_pgd(mm))) {
@@ -511,6 +518,8 @@ void mmput(struct mm_struct *mm)
spin_unlock(&mmlist_lock);
}
put_swap_token(mm);
+ if (mm->binfmt)
+ module_put(mm->binfmt->module);
mmdrop(mm);
}
}
@@ -636,9 +645,14 @@ struct mm_struct *dup_mm(struct task_struct *tsk)
mm->hiwater_rss = get_mm_rss(mm);
mm->hiwater_vm = mm->total_vm;
+ if (mm->binfmt && !try_module_get(mm->binfmt->module))
+ goto free_pt;
+
return mm;
free_pt:
+ /* don't put binfmt in mmput, we haven't got module yet */
+ mm->binfmt = NULL;
mmput(mm);
fail_nomem:
@@ -979,6 +993,16 @@ static struct task_struct *copy_process(unsigned long clone_flags,
if ((clone_flags & CLONE_SIGHAND) && !(clone_flags & CLONE_VM))
return ERR_PTR(-EINVAL);
+ /*
+ * Siblings of global init remain as zombies on exit since they are
+ * not reaped by their parent (swapper). To solve this and to avoid
+ * multi-rooted process trees, prevent global and container-inits
+ * from creating siblings.
+ */
+ if ((clone_flags & CLONE_PARENT) &&
+ current->signal->flags & SIGNAL_UNKILLABLE)
+ return ERR_PTR(-EINVAL);
+
retval = security_task_create(clone_flags);
if (retval)
goto fork_out;
@@ -1020,9 +1044,6 @@ static struct task_struct *copy_process(unsigned long clone_flags,
if (!try_module_get(task_thread_info(p)->exec_domain->module))
goto bad_fork_cleanup_count;
- if (p->binfmt && !try_module_get(p->binfmt->module))
- goto bad_fork_cleanup_put_domain;
-
p->did_exec = 0;
delayacct_tsk_init(p); /* Must remain after dup_task_struct() */
copy_flags(clone_flags, p);
@@ -1310,9 +1331,6 @@ bad_fork_cleanup_cgroup:
#endif
cgroup_exit(p, cgroup_callbacks_done);
delayacct_tsk_free(p);
- if (p->binfmt)
- module_put(p->binfmt->module);
-bad_fork_cleanup_put_domain:
module_put(task_thread_info(p)->exec_domain->module);
bad_fork_cleanup_count:
atomic_dec(&p->cred->user->processes);