projects/linux·commit 2dbb51c4

mm: make defensive checks around PFN values registered for memory usage

2dbb51c4 · Mel Gorman <[email protected]> · 2008-07-23 21:26:52 -07:00

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 <[email protected]>
Cc: Christoph Lameter <[email protected]>
Cc: Andy Whitcroft <[email protected]>
Cc: Ingo Molnar <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Commit
2dbb51c49f4fecb8330e43247a0edfbc4b2b8974
Parents
708614e6

Changes

4 files changed · +44 −8

FileStatusAddDelContent
mm/bootmem.cmodified+1−0View file
mm/internal.hmodified+12−0View file
mm/page_alloc.cmodified+2−0View file
mm/sparse.cmodified+29−8View file

mm/bootmem.c

View file
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 @@ static unsigned long __init init_bootmem_core(pg_data_t *pgdat,
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;

mm/internal.h

View file
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 @@ static inline void mminit_verify_page_links(struct page *page,
{
}
#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

mm/page_alloc.c

View file
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 @@ void __init add_active_range(unsigned int nid, unsigned long start_pfn,
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)

mm/sparse.c

View file
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 @@ static inline int sparse_early_nid(struct mem_section *section)
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 __init node_memmap_size_bytes(int nid, unsigned long start_pfn,
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;