[PATCH] mm: fix boundary checking in free_bootmem_core
With numa enabled, some callers could have a range of memory on one node but
try to free that on other node. This can cause some pages to be freed
wrongly.
For example: when we try to allocate 128g boot ram early for gart/swiotlb, and
free that range later so gart/swiotlb can get some range afterwards.
With this patch, we don't need to care which node holds the range, just loop
to call free_bootmem_node for all online nodes.
This patch make free_bootmem_core() more robust by trimming the sidx and eidx
according the ram range that the node has.
Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Index: linux-2.6/mm/bootmem.c
===================================================================
--- linux-2.6.orig/mm/bootmem.c
+++ linux-2.6/mm/bootmem.c
@@ -125,6 +125,7 @@ static int __init reserve_bootmem_core(b
BUG_ON(!size);
BUG_ON(PFN_DOWN(addr) >= bdata->node_low_pfn);
BUG_ON(PFN_UP(addr + size) > bdata->node_low_pfn);
+ BUG_ON(addr < bdata->node_boot_start);
sidx = PFN_DOWN(addr - bdata->node_boot_start);
eidx = PFN_UP(addr + size - bdata->node_boot_start);
@@ -156,21 +157,31 @@ static void __init free_bootmem_core(boo
unsigned long sidx, eidx;
unsigned long i;
+ BUG_ON(!size);
+
+ /* out range */
+ if (addr + size < bdata->node_boot_start ||
+ PFN_DOWN(addr) > bdata->node_low_pfn)
+ return;
/*
* round down end of usable mem, partially free pages are
* considered reserved.
*/
- BUG_ON(!size);
- BUG_ON(PFN_DOWN(addr + size) > bdata->node_low_pfn);
- if (addr < bdata->last_success)
+ if (addr >= bdata->node_boot_start && addr < bdata->last_success)
bdata->last_success = addr;
/*
- * Round up the beginning of the address.
+ * Round up to index to the range.
*/
- sidx = PFN_UP(addr) - PFN_DOWN(bdata->node_boot_start);
+ if (PFN_UP(addr) > PFN_DOWN(bdata->node_boot_start))
+ sidx = PFN_UP(addr) - PFN_DOWN(bdata->node_boot_start);
+ else
+ sidx = 0;
+
eidx = PFN_DOWN(addr + size - bdata->node_boot_start);
+ if (eidx > bdata->node_low_pfn - PFN_DOWN(bdata->node_boot_start))
+ eidx = bdata->node_low_pfn - PFN_DOWN(bdata->node_boot_start);
for (i = sidx; i < eidx; i++) {
if (unlikely(!test_and_clear_bit(i, bdata->node_bootmem_map)))
--
