kmemcheck: add hooks for the page allocator
This adds support for tracking the initializedness of memory that
was allocated with the page allocator. Highmem requests are not
tracked.
Cc: Dave Hansen <dave@linux.vnet.ibm.com>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
[build fix for !CONFIG_KMEMCHECK]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
[rebased for mainline inclusion]
Signed-off-by: Vegard Nossum <vegard.nossum@gmail.com>
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 17d5f53..0727896 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -23,6 +23,7 @@
#include <linux/bootmem.h>
#include <linux/compiler.h>
#include <linux/kernel.h>
+#include <linux/kmemcheck.h>
#include <linux/module.h>
#include <linux/suspend.h>
#include <linux/pagevec.h>
@@ -546,6 +547,8 @@
int i;
int bad = 0;
+ kmemcheck_free_shadow(page, order);
+
for (i = 0 ; i < (1 << order) ; ++i)
bad += free_pages_check(page + i);
if (bad)
@@ -994,6 +997,8 @@
struct per_cpu_pages *pcp;
unsigned long flags;
+ kmemcheck_free_shadow(page, 0);
+
if (PageAnon(page))
page->mapping = NULL;
if (free_pages_check(page))
@@ -1047,6 +1052,16 @@
VM_BUG_ON(PageCompound(page));
VM_BUG_ON(!page_count(page));
+
+#ifdef CONFIG_KMEMCHECK
+ /*
+ * Split shadow pages too, because free(page[0]) would
+ * otherwise free the whole shadow.
+ */
+ if (kmemcheck_page_is_tracked(page))
+ split_page(virt_to_page(page[0].shadow), order);
+#endif
+
for (i = 1; i < (1 << order); i++)
set_page_refcounted(page + i);
}
@@ -1667,7 +1682,10 @@
dump_stack();
show_mem();
}
+ return page;
got_pg:
+ if (kmemcheck_enabled)
+ kmemcheck_pagealloc_alloc(page, order, gfp_mask);
return page;
}
EXPORT_SYMBOL(__alloc_pages_internal);