From: Wei Yang Date: Thu, 2 Apr 2020 04:09:24 +0000 (-0700) Subject: mm/sparsemem: get address to page struct instead of address to pfn X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=4627d76dcf0482c56e925a3477948df136255f0c;p=linux.git 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: ba72b4c8cf60 ("mm/sparsemem: support sub-section hotplug") Signed-off-by: Wei Yang Signed-off-by: Andrew Morton Acked-by: David Hildenbrand Cc: Dan Williams Cc: Baoquan He Link: http://lkml.kernel.org/r/20200210005048.10437-1-richardw.yang@linux.intel.com Signed-off-by: Linus Torvalds --- diff --git a/mm/sparse.c b/mm/sparse.c index 65599e8bd6365..55fe305e8d7ba 100644 --- a/mm/sparse.c +++ b/mm/sparse.c @@ -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;