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| author |   David Hildenbrand <david@redhat.com> | 2019-09-23 15:36:05 -0700 |
|---|---|---|
| committer |   Linus Torvalds <torvalds@linux-foundation.org> | 2019-09-24 15:54:09 -0700 |
| commit | bd02cc01d342b43618c86e25552150f7a7e09080 (patch) | |
| tree | a7fb742c9cb692c07ff29e5d856900981e341896 /mm/memory_hotplug.c | |
| parent | mm/memory_hotplug: simplify online_pages_range() (diff) | |
| download | wireguard-linux-bd02cc01d342b43618c86e25552150f7a7e09080.tar.xz wireguard-linux-bd02cc01d342b43618c86e25552150f7a7e09080.zip | |
mm/memory_hotplug: make sure the pfn is aligned to the order when onlining
Commit a9cd410a3d29 ("mm/page_alloc.c: memory hotplug: free pages as
higher order") assumed that any PFN we get via memory resources is aligned
to to MAX_ORDER - 1, I am not convinced that is always true. Let's play
safe, check the alignment and fallback to single pages.
akpm: warn in this situation so we get to find out if and why this ever
occurs.
[akpm@linux-foundation.org: add WARN_ON_ONCE()]
Link: http://lkml.kernel.org/r/20190814154109.3448-5-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Cc: Arun KS <arunks@codeaurora.org>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Nadav Amit <namit@vmware.com>
Cc: Wei Yang <richardw.yang@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/memory_hotplug.c')
| -rw-r--r-- | mm/memory_hotplug.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index b5ad646df86b..aa54e15ea830 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -646,6 +646,9 @@ static int online_pages_range(unsigned long start_pfn, unsigned long nr_pages, */ for (pfn = start_pfn; pfn < end_pfn; pfn += 1ul << order) { order = min(MAX_ORDER - 1, get_order(PFN_PHYS(end_pfn - pfn))); + /* __free_pages_core() wants pfns to be aligned to the order */ + if (WARN_ON_ONCE(!IS_ALIGNED(pfn, 1ul << order))) + order = 0; (*online_page_callback)(pfn_to_page(pfn), order); } |