From 4627d76dcf0482c56e925a3477948df136255f0c Mon Sep 17 00:00:00 2001 From: Wei Yang Date: Wed, 1 Apr 2020 21:09:24 -0700 Subject: 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 --- mm/sparse.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'mm/sparse.c') diff --git a/mm/sparse.c b/mm/sparse.c index 65599e8bd636..55fe305e8d7b 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; -- cgit