1 files changed, 124 insertions, 0 deletions
diff --git a/arch/x86/mm/kmemcheck/shadow.c b/arch/x86/mm/kmemcheck/shadow.c
new file mode 100644
index 000000000000..196dddc70cf6
--- /dev/null
+++ b/arch/x86/mm/kmemcheck/shadow.c
@@ -0,0 +1,124 @@
+#include <linux/kmemcheck.h>
+#include <linux/module.h>
+#include <linux/mm.h>
+#include <linux/module.h>
+
+#include <asm/page.h>
+#include <asm/pgtable.h>
+
+#include "pte.h"
+#include "shadow.h"
+
+/*
+ * Return the shadow address for the given address. Returns NULL if the
+ * address is not tracked.
+ *
+ * We need to be extremely careful not to follow any invalid pointers,
+ * because this function can be called for *any* possible address.
+ */
+void *kmemcheck_shadow_lookup(unsigned long address)
+{
+	pte_t *pte;
+	struct page *page;
+
+	if (!virt_addr_valid(address))
+		return NULL;
+
+	pte = kmemcheck_pte_lookup(address);
+	if (!pte)
+		return NULL;
+
+	page = virt_to_page(address);
+	if (!page->shadow)
+		return NULL;
+	return page->shadow + (address & (PAGE_SIZE - 1));
+}
+
+static void mark_shadow(void *address, unsigned int n,
+	enum kmemcheck_shadow status)
+{
+	void *shadow;
+
+	shadow = kmemcheck_shadow_lookup((unsigned long) address);
+	if (!shadow)
+		return;
+	memset(shadow, status, n);
+}
+
+void kmemcheck_mark_unallocated(void *address, unsigned int n)
+{
+	mark_shadow(address, n, KMEMCHECK_SHADOW_UNALLOCATED);
+}
+
+void kmemcheck_mark_uninitialized(void *address, unsigned int n)
+{
+	mark_shadow(address, n, KMEMCHECK_SHADOW_UNINITIALIZED);
+}
+
+/*
+ * Fill the shadow memory of the given address such that the memory at that
+ * address is marked as being initialized.
+ */
+void kmemcheck_mark_initialized(void *address, unsigned int n)
+{
+	mark_shadow(address, n, KMEMCHECK_SHADOW_INITIALIZED);
+}
+EXPORT_SYMBOL_GPL(kmemcheck_mark_initialized);
+
+void kmemcheck_mark_freed(void *address, unsigned int n)
+{
+	mark_shadow(address, n, KMEMCHECK_SHADOW_FREED);
+}
+
+void kmemcheck_mark_unallocated_pages(struct page *p, unsigned int n)
+{
+	unsigned int i;
+
+	for (i = 0; i < n; ++i)
+		kmemcheck_mark_unallocated(page_address(&p[i]), PAGE_SIZE);
+}
+
+void kmemcheck_mark_uninitialized_pages(struct page *p, unsigned int n)
+{
+	unsigned int i;
+
+	for (i = 0; i < n; ++i)
+		kmemcheck_mark_uninitialized(page_address(&p[i]), PAGE_SIZE);
+}
+
+enum kmemcheck_shadow kmemcheck_shadow_test(void *shadow, unsigned int size)
+{
+	uint8_t *x;
+	unsigned int i;
+
+	x = shadow;
+
+#ifdef CONFIG_KMEMCHECK_PARTIAL_OK
+	/*
+	 * Make sure _some_ bytes are initialized. Gcc frequently generates
+	 * code to access neighboring bytes.
+	 */
+	for (i = 0; i < size; ++i) {
+		if (x[i] == KMEMCHECK_SHADOW_INITIALIZED)
+			return x[i];
+	}
+#else
+	/* All bytes must be initialized. */
+	for (i = 0; i < size; ++i) {
+		if (x[i] != KMEMCHECK_SHADOW_INITIALIZED)
+			return x[i];
+	}
+#endif
+
+	return x[0];
+}
+
+void kmemcheck_shadow_set(void *shadow, unsigned int size)
+{
+	uint8_t *x;
+	unsigned int i;
+
+	x = shadow;
+	for (i = 0; i < size; ++i)
+		x[i] = KMEMCHECK_SHADOW_INITIALIZED;
+}