Commit 4627d76d authored by Wei Yang's avatar Wei Yang Committed by Linus Torvalds

mm/sparsemem: get address to page struct instead of address to pfn

memmap should be the address to page struct instead of address to pfn.

As mentioned by David, if system memory and devmem sit within a section,
the mismatch address would lead kdump to dump unexpected memory.

Since sub-section only works for SPARSEMEM_VMEMMAP, pfn_to_page() is valid
to get the page struct address at this point.

Fixes: ba72b4c8 ("mm/sparsemem: support sub-section hotplug")
Signed-off-by: default avatarWei Yang <richardw.yang@linux.intel.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Acked-by: default avatarDavid Hildenbrand <david@redhat.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Baoquan He <bhe@redhat.com>
Link: http://lkml.kernel.org/r/20200210005048.10437-1-richardw.yang@linux.intel.comSigned-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 0c28759e
...@@ -894,7 +894,7 @@ int __meminit sparse_add_section(int nid, unsigned long start_pfn, ...@@ -894,7 +894,7 @@ int __meminit sparse_add_section(int nid, unsigned long start_pfn,
/* Align memmap to section boundary in the subsection case */ /* Align memmap to section boundary in the subsection case */
if (section_nr_to_pfn(section_nr) != start_pfn) if (section_nr_to_pfn(section_nr) != start_pfn)
memmap = pfn_to_kaddr(section_nr_to_pfn(section_nr)); memmap = pfn_to_page(section_nr_to_pfn(section_nr));
sparse_init_one_section(ms, section_nr, memmap, ms->usage, 0); sparse_init_one_section(ms, section_nr, memmap, ms->usage, 0);
return 0; return 0;
......
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