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-rw-r--r--mm/gup.c16
1 files changed, 10 insertions, 6 deletions
diff --git a/mm/gup.c b/mm/gup.c
index f0f3f4052b94..102877ed77a4 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -1547,19 +1547,23 @@ finish_or_fault:
* NULL wherever the ZERO_PAGE, or an anonymous pte_none, has been found -
* allowing a hole to be left in the corefile to save diskspace.
*
- * Called without mmap_lock, but after all other threads have been killed.
+ * Called without mmap_lock (takes and releases the mmap_lock by itself).
*/
#ifdef CONFIG_ELF_CORE
struct page *get_dump_page(unsigned long addr)
{
- struct vm_area_struct *vma;
+ struct mm_struct *mm = current->mm;
struct page *page;
+ int locked = 1;
+ int ret;
- if (__get_user_pages_locked(current->mm, addr, 1, &page, &vma, NULL,
- FOLL_FORCE | FOLL_DUMP | FOLL_GET) < 1)
+ if (mmap_read_lock_killable(mm))
return NULL;
- flush_cache_page(vma, addr, page_to_pfn(page));
- return page;
+ ret = __get_user_pages_locked(mm, addr, 1, &page, NULL, &locked,
+ FOLL_FORCE | FOLL_DUMP | FOLL_GET);
+ if (locked)
+ mmap_read_unlock(mm);
+ return (ret == 1) ? page : NULL;
}
#endif /* CONFIG_ELF_CORE */