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authorWei Yang <richard.weiyang@linux.alibaba.com>2020-08-06 23:23:59 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2020-08-07 11:33:27 -0700
commit6cda72047ea46272ecb9cc71acf1231cea07167a (patch)
treee352a0b7bf692432e982ac703cf120f34956f19f /mm
parentef69bc9f689de8380688be742f9b9df615d42429 (diff)
mm/sparse: only sub-section aligned range would be populated
There are two code path which invoke __populate_section_memmap() * sparse_init_nid() * sparse_add_section() For both case, we are sure the memory range is sub-section aligned. * we pass PAGES_PER_SECTION to sparse_init_nid() * we check range by check_pfn_span() before calling sparse_add_section() Also, the counterpart of __populate_section_memmap(), we don't do such calculation and check since the range is checked by check_pfn_span() in __remove_pages(). Clear the calculation and check to keep it simple and comply with its counterpart. Signed-off-by: Wei Yang <richard.weiyang@linux.alibaba.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: David Hildenbrand <david@redhat.com> Link: http://lkml.kernel.org/r/20200703031828.14645-1-richard.weiyang@linux.alibaba.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm')
-rw-r--r--mm/sparse-vmemmap.c20
1 files changed, 6 insertions, 14 deletions
diff --git a/mm/sparse-vmemmap.c b/mm/sparse-vmemmap.c
index 41eeac67723b..16183d85a7d5 100644
--- a/mm/sparse-vmemmap.c
+++ b/mm/sparse-vmemmap.c
@@ -251,20 +251,12 @@ int __meminit vmemmap_populate_basepages(unsigned long start, unsigned long end,
struct page * __meminit __populate_section_memmap(unsigned long pfn,
unsigned long nr_pages, int nid, struct vmem_altmap *altmap)
{
- unsigned long start;
- unsigned long end;
-
- /*
- * The minimum granularity of memmap extensions is
- * PAGES_PER_SUBSECTION as allocations are tracked in the
- * 'subsection_map' bitmap of the section.
- */
- end = ALIGN(pfn + nr_pages, PAGES_PER_SUBSECTION);
- pfn &= PAGE_SUBSECTION_MASK;
- nr_pages = end - pfn;
-
- start = (unsigned long) pfn_to_page(pfn);
- end = start + nr_pages * sizeof(struct page);
+ unsigned long start = (unsigned long) pfn_to_page(pfn);
+ unsigned long end = start + nr_pages * sizeof(struct page);
+
+ if (WARN_ON_ONCE(!IS_ALIGNED(pfn, PAGES_PER_SUBSECTION) ||
+ !IS_ALIGNED(nr_pages, PAGES_PER_SUBSECTION)))
+ return NULL;
if (vmemmap_populate(start, end, nid, altmap))
return NULL;