-#ifdef CONFIG_STACK_GROWSUP
- if (write) {
- ret = expand_downwards(bprm->vma, pos);
- if (ret < 0)
+ /*
+ * Avoid relying on expanding the stack down in GUP (which
+ * does not work for STACK_GROWSUP anyway), and just do it
+ * by hand ahead of time.
+ */
+ if (write && pos < vma->vm_start) {
+ mmap_write_lock(mm);
+ ret = expand_downwards(vma, pos);
+ if (unlikely(ret < 0)) {
+ mmap_write_unlock(mm);