[PATCH v1 6/7] virtio-mem: use page_offline_(start|end) when setting PageOffline()
From: David Hildenbrand <hidden>
Date: 2021-04-29 12:26:51
Also in:
linux-fsdevel, linux-hyperv, linux-mm, lkml
Subsystem:
memory management, memory management - core, the rest, virtio core, virtio mem driver · Maintainers:
Andrew Morton, David Hildenbrand, Linus Torvalds, "Michael S. Tsirkin", Jason Wang
Let's properly use page_offline_(start|end) to synchronize setting PageOffline(), so we won't have valid page access to unplugged memory regions from /proc/kcore. Signed-off-by: David Hildenbrand <redacted> --- drivers/virtio/virtio_mem.c | 2 ++ mm/util.c | 2 ++ 2 files changed, 4 insertions(+)
diff --git a/drivers/virtio/virtio_mem.c b/drivers/virtio/virtio_mem.c
index 10ec60d81e84..dc2a2e2b2ff8 100644
--- a/drivers/virtio/virtio_mem.c
+++ b/drivers/virtio/virtio_mem.c@@ -1065,6 +1065,7 @@ static int virtio_mem_memory_notifier_cb(struct notifier_block *nb, static void virtio_mem_set_fake_offline(unsigned long pfn, unsigned long nr_pages, bool onlined) { + page_offline_begin(); for (; nr_pages--; pfn++) { struct page *page = pfn_to_page(pfn);
@@ -1075,6 +1076,7 @@ static void virtio_mem_set_fake_offline(unsigned long pfn, ClearPageReserved(page); } } + page_offline_end(); } /*
diff --git a/mm/util.c b/mm/util.c
index 95395d4e4209..d0e357bd65e6 100644
--- a/mm/util.c
+++ b/mm/util.c@@ -1046,8 +1046,10 @@ void page_offline_begin(void) { down_write(&page_offline_rwsem); } +EXPORT_SYMBOL(page_offline_begin); void page_offline_end(void) { up_write(&page_offline_rwsem); } +EXPORT_SYMBOL(page_offline_end);
--
2.30.2
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