+
+static struct vm_area_struct *first_vma(struct task_struct *tsk,
+ struct vm_area_struct *gate_vma)
+{
+ struct vm_area_struct *ret = tsk->mm->mmap;
+
+ if (ret)
+ return ret;
+ return gate_vma;
+}
+
+/*
+ * Helper function for iterating across a vma list. It ensures that the caller
+ * will visit `gate_vma' prior to terminating the search.
+ */
+static struct vm_area_struct *next_vma(struct vm_area_struct *this_vma,
+ struct vm_area_struct *gate_vma)
+{
+ struct vm_area_struct *ret;
+
+ ret = this_vma->vm_next;
+ if (ret)
+ return ret;
+ if (this_vma == gate_vma)
+ return NULL;
+ return gate_vma;
+}
+
+/*
+ * Under the mmap_lock, take a snapshot of relevant information about the task's
+ * VMAs.
+ */
+int dump_vma_snapshot(struct coredump_params *cprm, int *vma_count,
+ struct core_vma_metadata **vma_meta,
+ size_t *vma_data_size_ptr)
+{
+ struct vm_area_struct *vma, *gate_vma;
+ struct mm_struct *mm = current->mm;
+ int i;
+ size_t vma_data_size = 0;
+
+ /*
+ * Once the stack expansion code is fixed to not change VMA bounds
+ * under mmap_lock in read mode, this can be changed to take the
+ * mmap_lock in read mode.
+ */
+ if (mmap_write_lock_killable(mm))
+ return -EINTR;
+
+ gate_vma = get_gate_vma(mm);
+ *vma_count = mm->map_count + (gate_vma ? 1 : 0);
+
+ *vma_meta = kvmalloc_array(*vma_count, sizeof(**vma_meta), GFP_KERNEL);
+ if (!*vma_meta) {
+ mmap_write_unlock(mm);
+ return -ENOMEM;
+ }
+
+ for (i = 0, vma = first_vma(current, gate_vma); vma != NULL;
+ vma = next_vma(vma, gate_vma), i++) {
+ struct core_vma_metadata *m = (*vma_meta) + i;
+
+ m->start = vma->vm_start;
+ m->end = vma->vm_end;
+ m->flags = vma->vm_flags;
+ m->dump_size = vma_dump_size(vma, cprm->mm_flags);
+
+ vma_data_size += m->dump_size;
+ }
+
+ mmap_write_unlock(mm);
+
+ if (WARN_ON(i != *vma_count))
+ return -EFAULT;
+
+ *vma_data_size_ptr = vma_data_size;
+ return 0;
+}