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: ba72b4c8cf ("mm/sparsemem: support sub-section hotplug")
Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: David 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.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Wei Yang 2020-04-01 21:09:24 -07:00 committed by Linus Torvalds
parent 0c28759ee3
commit 4627d76dcf

View File

@ -894,7 +894,7 @@ int __meminit sparse_add_section(int nid, unsigned long start_pfn,
/* Align memmap to section boundary in the subsection case */
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);
return 0;