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author | Wei Yang <richard.weiyang@linux.alibaba.com> | 2020-08-06 23:23:59 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-08-07 11:33:27 -0700 |
commit | 6cda72047ea46272ecb9cc71acf1231cea07167a (patch) | |
tree | e352a0b7bf692432e982ac703cf120f34956f19f | |
parent | ef69bc9f689de8380688be742f9b9df615d42429 (diff) | |
download | linux-stable-6cda72047ea46272ecb9cc71acf1231cea07167a.tar.gz linux-stable-6cda72047ea46272ecb9cc71acf1231cea07167a.tar.bz2 linux-stable-6cda72047ea46272ecb9cc71acf1231cea07167a.zip |
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>
-rw-r--r-- | mm/sparse-vmemmap.c | 20 |
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; |