diff options
Diffstat (limited to 'mm/util.c')
| -rw-r--r-- | mm/util.c | 41 |
1 files changed, 41 insertions, 0 deletions
diff --git a/mm/util.c b/mm/util.c index 136ac4f322b8..ae962b31de88 100644 --- a/mm/util.c +++ b/mm/util.c @@ -239,6 +239,47 @@ void __vma_link_list(struct mm_struct *mm, struct vm_area_struct *vma, next->vm_prev = vma; } +/* Check if the vma is being used as a stack by this task */ +static int vm_is_stack_for_task(struct task_struct *t, + struct vm_area_struct *vma) +{ + return (vma->vm_start <= KSTK_ESP(t) && vma->vm_end >= KSTK_ESP(t)); +} + +/* + * Check if the vma is being used as a stack. + * If is_group is non-zero, check in the entire thread group or else + * just check in the current task. Returns the pid of the task that + * the vma is stack for. + */ +pid_t vm_is_stack(struct task_struct *task, + struct vm_area_struct *vma, int in_group) +{ + pid_t ret = 0; + + if (vm_is_stack_for_task(task, vma)) + return task->pid; + + if (in_group) { + struct task_struct *t; + rcu_read_lock(); + if (!pid_alive(task)) + goto done; + + t = task; + do { + if (vm_is_stack_for_task(t, vma)) { + ret = t->pid; + goto done; + } + } while_each_thread(task, t); +done: + rcu_read_unlock(); + } + + return ret; +} + #if defined(CONFIG_MMU) && !defined(HAVE_ARCH_PICK_MMAP_LAYOUT) void arch_pick_mmap_layout(struct mm_struct *mm) { |