mm: make defensive checks around PFN values registered for memory usage
There are a number of different views to how much memory is currently active.
There is the arch-independent zone-sizing view, the bootmem allocator and
memory models view.
Architectures register this information at different times and is not
necessarily in sync particularly with respect to some SPARSEMEM limitations.
This patch introduces mminit_validate_memmodel_limits() which is able to
validate and correct PFN ranges with respect to the memory model. It is only
SPARSEMEM that currently validates itself.
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Andy Whitcroft <apw@shadowen.org>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/bootmem.c b/mm/bootmem.c
index 8d9f60e..9f4bbc5 100644
--- a/mm/bootmem.c
+++ b/mm/bootmem.c
@@ -91,6 +91,7 @@
bootmem_data_t *bdata = pgdat->bdata;
unsigned long mapsize;
+ mminit_validate_memmodel_limits(&start, &end);
bdata->node_bootmem_map = phys_to_virt(PFN_PHYS(mapstart));
bdata->node_boot_start = PFN_PHYS(start);
bdata->node_low_pfn = end;
diff --git a/mm/internal.h b/mm/internal.h
index 7a4a288..5d17f3e 100644
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -98,4 +98,16 @@
{
}
#endif /* CONFIG_DEBUG_MEMORY_INIT */
+
+/* mminit_validate_memmodel_limits is independent of CONFIG_DEBUG_MEMORY_INIT */
+#if defined(CONFIG_SPARSEMEM)
+extern void mminit_validate_memmodel_limits(unsigned long *start_pfn,
+ unsigned long *end_pfn);
+#else
+static inline void mminit_validate_memmodel_limits(unsigned long *start_pfn,
+ unsigned long *end_pfn)
+{
+}
+#endif /* CONFIG_SPARSEMEM */
+
#endif
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index acab6ad..0adb66e 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -3536,6 +3536,8 @@
nid, start_pfn, end_pfn,
nr_nodemap_entries, MAX_ACTIVE_REGIONS);
+ mminit_validate_memmodel_limits(&start_pfn, &end_pfn);
+
/* Merge with existing active regions if possible */
for (i = 0; i < nr_nodemap_entries; i++) {
if (early_node_map[i].nid != nid)
diff --git a/mm/sparse.c b/mm/sparse.c
index 36511c7..7a36509 100644
--- a/mm/sparse.c
+++ b/mm/sparse.c
@@ -12,6 +12,7 @@
#include <asm/dma.h>
#include <asm/pgalloc.h>
#include <asm/pgtable.h>
+#include "internal.h"
/*
* Permanent SPARSEMEM data:
@@ -147,22 +148,41 @@
return (section->section_mem_map >> SECTION_NID_SHIFT);
}
-/* Record a memory area against a node. */
-void __init memory_present(int nid, unsigned long start, unsigned long end)
+/* Validate the physical addressing limitations of the model */
+void __meminit mminit_validate_memmodel_limits(unsigned long *start_pfn,
+ unsigned long *end_pfn)
{
- unsigned long max_arch_pfn = 1UL << (MAX_PHYSMEM_BITS-PAGE_SHIFT);
- unsigned long pfn;
+ unsigned long max_sparsemem_pfn = 1UL << (MAX_PHYSMEM_BITS-PAGE_SHIFT);
/*
* Sanity checks - do not allow an architecture to pass
* in larger pfns than the maximum scope of sparsemem:
*/
- if (start >= max_arch_pfn)
- return;
- if (end >= max_arch_pfn)
- end = max_arch_pfn;
+ if (*start_pfn > max_sparsemem_pfn) {
+ mminit_dprintk(MMINIT_WARNING, "pfnvalidation",
+ "Start of range %lu -> %lu exceeds SPARSEMEM max %lu\n",
+ *start_pfn, *end_pfn, max_sparsemem_pfn);
+ WARN_ON_ONCE(1);
+ *start_pfn = max_sparsemem_pfn;
+ *end_pfn = max_sparsemem_pfn;
+ }
+
+ if (*end_pfn > max_sparsemem_pfn) {
+ mminit_dprintk(MMINIT_WARNING, "pfnvalidation",
+ "End of range %lu -> %lu exceeds SPARSEMEM max %lu\n",
+ *start_pfn, *end_pfn, max_sparsemem_pfn);
+ WARN_ON_ONCE(1);
+ *end_pfn = max_sparsemem_pfn;
+ }
+}
+
+/* Record a memory area against a node. */
+void __init memory_present(int nid, unsigned long start, unsigned long end)
+{
+ unsigned long pfn;
start &= PAGE_SECTION_MASK;
+ mminit_validate_memmodel_limits(&start, &end);
for (pfn = start; pfn < end; pfn += PAGES_PER_SECTION) {
unsigned long section = pfn_to_section_nr(pfn);
struct mem_section *ms;
@@ -187,6 +207,7 @@
unsigned long pfn;
unsigned long nr_pages = 0;
+ mminit_validate_memmodel_limits(&start_pfn, &end_pfn);
for (pfn = start_pfn; pfn < end_pfn; pfn += PAGES_PER_SECTION) {
if (nid != early_pfn_to_nid(pfn))
continue;