Hello Naoya Horiguchi,
The patch 3b325af8e5fe: "mm/hwpoison: fix race between hugetlb
free/demotion and memory_failure_hugetlb()" from Apr 5, 2022, leads
to the following Smatch static checker warning:
mm/memory-failure.c:1537 __get_huge_page_for_hwpoison()
warn: sleeping in atomic context
mm/memory-failure.c
1515 int __get_huge_page_for_hwpoison(unsigned long pfn, int flags)
1516 {
1517 struct page *page = pfn_to_page(pfn);
1518 struct page *head = compound_head(page);
1519 int ret = 2; /* fallback to normal page handling */
1520 bool count_increased = false;
1521
1522 if (!PageHeadHuge(head))
1523 goto out;
1524
1525 if (flags & MF_COUNT_INCREASED) {
1526 ret = 1;
1527 count_increased = true;
1528 } else if (HPageFreed(head) || HPageMigratable(head)) {
1529 ret = get_page_unless_zero(head);
1530 if (ret)
1531 count_increased = true;
1532 } else {
1533 ret = -EBUSY;
1534 goto out;
1535 }
1536
--> 1537 lock_page(head);
^^^^^^^^^^^^^^^
Sleeps. But this is called from get_huge_page_for_hwpoison() with
a spinlock held.
1538
1539 if (hwpoison_filter(page)) {
1540 ret = -EOPNOTSUPP;
1541 goto unlock;
1542 }
1543
1544 if (TestSetPageHWPoison(head)) {
1545 ret = -EHWPOISON;
1546 goto unlock;
1547 }
1548
1549 /* keep locking page. */
1550 return ret;
1551 unlock:
1552 unlock_page(head);
1553 if (count_increased)
1554 put_page(head);
1555 out:
1556 return ret;
1557 }
regards,
dan carpenter
