From: Wei Yang <richardw.yang@linux.intel.com>
To: akpm@linux-foundation.org, osalvador@suse.de, dan.j.williams@intel.com
Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org,
Wei Yang <richardw.yang@linux.intel.com>,
David Hildenbrand <david@redhat.com>, Baoquan He <bhe@redhat.com>
Subject: [Patch v2] mm/sparsemem: get address to page struct instead of address to pfn
Date: Mon, 10 Feb 2020 08:50:48 +0800 [thread overview]
Message-ID: <20200210005048.10437-1-richardw.yang@linux.intel.com> (raw)
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 <richardw.yang@linux.intel.com>
CC: Dan Williams <dan.j.williams@intel.com>
CC: David Hildenbrand <david@redhat.com>
CC: Baoquan He <bhe@redhat.com>
---
v2:
* adjust comment to mention the mismatch data would affect kdump
---
mm/sparse.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/mm/sparse.c b/mm/sparse.c
index 586d85662978..4862ec2cfbc0 100644
--- a/mm/sparse.c
+++ b/mm/sparse.c
@@ -887,7 +887,7 @@ 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;
--
2.17.1
next reply other threads:[~2020-02-10 0:50 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-10 0:50 Wei Yang [this message]
2020-02-10 9:00 ` [Patch v2] mm/sparsemem: get address to page struct instead of address to pfn David Hildenbrand
2020-02-10 9:13 ` David Hildenbrand
2020-02-10 23:16 ` Wei Yang
2020-02-11 14:01 ` David Hildenbrand
2020-02-12 2:28 ` Wei Yang
2020-02-12 11:22 ` David Hildenbrand
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