Fix corruption of memmap on IA64 SPARSEMEM when mem_section is not a power of 2

[safe/jmp/linux-2.6] / mm / sparse.c

diff --git a/mm/sparse.c b/mm/sparse.c
index 52843a7..1f4dbb8 100644 (file)
--- a/mm/sparse.c
+++ b/mm/sparse.c
@@ -206,7 +206,8 @@ struct page *sparse_decode_mem_map(unsigned long coded_mem_map, unsigned long pn
 }
 
 static int __meminit sparse_init_one_section(struct mem_section *ms,
-               unsigned long pnum, struct page *mem_map)
+               unsigned long pnum, struct page *mem_map,
+               unsigned long *pageblock_bitmap)
 {
        if (!present_section(ms))
                return -EINVAL;
@@ -214,6 +215,7 @@ static int __meminit sparse_init_one_section(struct mem_section *ms,
        ms->section_mem_map &= ~SECTION_MAP_MASK;
        ms->section_mem_map |= sparse_encode_mem_map(mem_map, pnum) |
                                                        SECTION_HAS_MEM_MAP;
+       ms->pageblock_flags = pageblock_bitmap;
 
        return 1;
 }
@@ -224,6 +226,38 @@ void *alloc_bootmem_high_node(pg_data_t *pgdat, unsigned long size)
        return NULL;
 }
 
+static unsigned long usemap_size(void)
+{
+       unsigned long size_bytes;
+       size_bytes = roundup(SECTION_BLOCKFLAGS_BITS, 8) / 8;
+       size_bytes = roundup(size_bytes, sizeof(unsigned long));
+       return size_bytes;
+}
+
+#ifdef CONFIG_MEMORY_HOTPLUG
+static unsigned long *__kmalloc_section_usemap(void)
+{
+       return kmalloc(usemap_size(), GFP_KERNEL);
+}
+#endif /* CONFIG_MEMORY_HOTPLUG */
+
+static unsigned long *sparse_early_usemap_alloc(unsigned long pnum)
+{
+       unsigned long *usemap;
+       struct mem_section *ms = __nr_to_section(pnum);
+       int nid = sparse_early_nid(ms);
+
+       usemap = alloc_bootmem_node(NODE_DATA(nid), usemap_size());
+       if (usemap)
+               return usemap;
+
+       /* Stupid: suppress gcc warning for SPARSEMEM && !NUMA */
+       nid = 0;
+
+       printk(KERN_WARNING "%s: allocation failed\n", __FUNCTION__);
+       return NULL;
+}
+
 #ifndef CONFIG_SPARSEMEM_VMEMMAP
 struct page __init *sparse_early_mem_map_populate(unsigned long pnum, int nid)
 {
@@ -268,6 +302,7 @@ void __init sparse_init(void)
 {
        unsigned long pnum;
        struct page *map;
+       unsigned long *usemap;
 
        for (pnum = 0; pnum < NR_MEM_SECTIONS; pnum++) {
                if (!present_section_nr(pnum))
@@ -276,7 +311,13 @@ void __init sparse_init(void)
                map = sparse_early_mem_map_alloc(pnum);
                if (!map)
                        continue;
-               sparse_init_one_section(__nr_to_section(pnum), pnum, map);
+
+               usemap = sparse_early_usemap_alloc(pnum);
+               if (!usemap)
+                       continue;
+
+               sparse_init_one_section(__nr_to_section(pnum), pnum, map,
+                                                               usemap);
        }
 }
 
@@ -332,6 +373,7 @@ int sparse_add_one_section(struct zone *zone, unsigned long start_pfn,
        struct pglist_data *pgdat = zone->zone_pgdat;
        struct mem_section *ms;
        struct page *memmap;
+       unsigned long *usemap;
        unsigned long flags;
        int ret;
 
@@ -341,6 +383,7 @@ int sparse_add_one_section(struct zone *zone, unsigned long start_pfn,
         */
        sparse_index_init(section_nr, pgdat->node_id);
        memmap = __kmalloc_section_memmap(nr_pages);
+       usemap = __kmalloc_section_usemap();
 
        pgdat_resize_lock(pgdat, &flags);
 
@@ -349,9 +392,14 @@ int sparse_add_one_section(struct zone *zone, unsigned long start_pfn,
                ret = -EEXIST;
                goto out;
        }
+
+       if (!usemap) {
+               ret = -ENOMEM;
+               goto out;
+       }
        ms->section_mem_map |= SECTION_MARKED_PRESENT;
 
-       ret = sparse_init_one_section(ms, section_nr, memmap);
+       ret = sparse_init_one_section(ms, section_nr, memmap, usemap);
 
 out:
        pgdat_resize_unlock(pgdat, &flags);