diff options
Diffstat (limited to 'mm/sparse.c')
| -rw-r--r-- | mm/sparse.c | 26 |
1 files changed, 13 insertions, 13 deletions
diff --git a/mm/sparse.c b/mm/sparse.c index 3918fc3eaef1..65599e8bd636 100644 --- a/mm/sparse.c +++ b/mm/sparse.c @@ -198,16 +198,6 @@ static void section_mark_present(struct mem_section *ms) ms->section_mem_map |= SECTION_MARKED_PRESENT; } -static inline unsigned long next_present_section_nr(unsigned long section_nr) -{ - do { - section_nr++; - if (present_section_nr(section_nr)) - return section_nr; - } while ((section_nr <= __highest_present_section_nr)); - - return -1; -} #define for_each_present_section_nr(start, section_nr) \ for (section_nr = next_present_section_nr(start-1); \ ((section_nr != -1) && \ @@ -744,6 +734,7 @@ static void section_deactivate(unsigned long pfn, unsigned long nr_pages, struct mem_section *ms = __pfn_to_section(pfn); bool section_is_early = early_section(ms); struct page *memmap = NULL; + bool empty; unsigned long *subsection_map = ms->usage ? &ms->usage->subsection_map[0] : NULL; @@ -774,7 +765,8 @@ static void section_deactivate(unsigned long pfn, unsigned long nr_pages, * For 2/ and 3/ the SPARSEMEM_VMEMMAP={y,n} cases are unified */ bitmap_xor(subsection_map, map, subsection_map, SUBSECTIONS_PER_SECTION); - if (bitmap_empty(subsection_map, SUBSECTIONS_PER_SECTION)) { + empty = bitmap_empty(subsection_map, SUBSECTIONS_PER_SECTION); + if (empty) { unsigned long section_nr = pfn_to_section_nr(pfn); /* @@ -789,13 +781,21 @@ static void section_deactivate(unsigned long pfn, unsigned long nr_pages, ms->usage = NULL; } memmap = sparse_decode_mem_map(ms->section_mem_map, section_nr); - ms->section_mem_map = (unsigned long)NULL; + /* + * Mark the section invalid so that valid_section() + * return false. This prevents code from dereferencing + * ms->usage array. + */ + ms->section_mem_map &= ~SECTION_HAS_MEM_MAP; } if (section_is_early && memmap) free_map_bootmem(memmap); else depopulate_section_memmap(pfn, nr_pages, altmap); + + if (empty) + ms->section_mem_map = (unsigned long)NULL; } static struct page * __meminit section_activate(int nid, unsigned long pfn, @@ -886,7 +886,7 @@ int __meminit sparse_add_section(int nid, unsigned long start_pfn, * Poison uninitialized struct pages in order to catch invalid flags * combinations. */ - page_init_poison(pfn_to_page(start_pfn), sizeof(struct page) * nr_pages); + page_init_poison(memmap, sizeof(struct page) * nr_pages); ms = __nr_to_section(section_nr); set_section_nid(section_nr, nid); |