8 files changed, 84 insertions, 4 deletions

diff --git a/arch/x86/include/asm/dma-mapping.h b/arch/x86/include/asm/dma-mapping.h
index f82fdc412c64..b93405b228b4 100644
--- a/arch/x86/include/asm/dma-mapping.h
+++ b/arch/x86/include/asm/dma-mapping.h
@@ -6,6 +6,7 @@
  * Documentation/DMA-API.txt for documentation.
  */
 
+#include <linux/kmemcheck.h>
 #include <linux/scatterlist.h>
 #include <linux/dma-debug.h>
 #include <linux/dma-attrs.h>
@@ -60,6 +61,7 @@ dma_map_single(struct device *hwdev, void *ptr, size_t size,
         dma_addr_t addr;
 
         BUG_ON(!valid_dma_direction(dir));
+        kmemcheck_mark_initialized(ptr, size);
         addr = ops->map_page(hwdev, virt_to_page(ptr),
                              (unsigned long)ptr & ~PAGE_MASK, size,
                              dir, NULL);
@@ -87,8 +89,12 @@ dma_map_sg(struct device *hwdev, struct scatterlist *sg,
 {
         struct dma_map_ops *ops = get_dma_ops(hwdev);
         int ents;
+        struct scatterlist *s;
+        int i;
 
         BUG_ON(!valid_dma_direction(dir));
+        for_each_sg(sg, s, nents, i)
+                kmemcheck_mark_initialized(sg_virt(s), s->length);
         ents = ops->map_sg(hwdev, sg, nents, dir, NULL);
         debug_dma_map_sg(hwdev, sg, nents, ents, dir);
 
@@ -200,6 +206,7 @@ static inline dma_addr_t dma_map_page(struct device *dev, struct page *page,
         dma_addr_t addr;
 
         BUG_ON(!valid_dma_direction(dir));
+        kmemcheck_mark_initialized(page_address(page) + offset, size);
         addr = ops->map_page(dev, page, offset, size, dir, NULL);
         debug_dma_map_page(dev, page, offset, size, dir, addr, false);
 
diff --git a/arch/x86/include/asm/kmemcheck.h b/arch/x86/include/asm/kmemcheck.h
new file mode 100644
index 000000000000..ed01518f297e
--- /dev/null
+++ b/arch/x86/include/asm/kmemcheck.h
@@ -0,0 +1,42 @@
+#ifndef ASM_X86_KMEMCHECK_H
+#define ASM_X86_KMEMCHECK_H
+
+#include <linux/types.h>
+#include <asm/ptrace.h>
+
+#ifdef CONFIG_KMEMCHECK
+bool kmemcheck_active(struct pt_regs *regs);
+
+void kmemcheck_show(struct pt_regs *regs);
+void kmemcheck_hide(struct pt_regs *regs);
+
+bool kmemcheck_fault(struct pt_regs *regs,
+        unsigned long address, unsigned long error_code);
+bool kmemcheck_trap(struct pt_regs *regs);
+#else
+static inline bool kmemcheck_active(struct pt_regs *regs)
+{
+        return false;
+}
+
+static inline void kmemcheck_show(struct pt_regs *regs)
+{
+}
+
+static inline void kmemcheck_hide(struct pt_regs *regs)
+{
+}
+
+static inline bool kmemcheck_fault(struct pt_regs *regs,
+        unsigned long address, unsigned long error_code)
+{
+        return false;
+}
+
+static inline bool kmemcheck_trap(struct pt_regs *regs)
+{
+        return false;
+}
+#endif /* CONFIG_KMEMCHECK */
+
+#endif
diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h
index 18ef7ebf2631..3cc06e3fceb8 100644
--- a/arch/x86/include/asm/pgtable.h
+++ b/arch/x86/include/asm/pgtable.h
@@ -317,6 +317,11 @@ static inline int pte_present(pte_t a)
         return pte_flags(a) & (_PAGE_PRESENT | _PAGE_PROTNONE);
 }
 
+static inline int pte_hidden(pte_t pte)
+{
+        return pte_flags(pte) & _PAGE_HIDDEN;
+}
+
 static inline int pmd_present(pmd_t pmd)
 {
         return pmd_flags(pmd) & _PAGE_PRESENT;
diff --git a/arch/x86/include/asm/pgtable_types.h b/arch/x86/include/asm/pgtable_types.h
index 4d258ad76a0f..54cb697f4900 100644
--- a/arch/x86/include/asm/pgtable_types.h
+++ b/arch/x86/include/asm/pgtable_types.h
@@ -18,7 +18,7 @@
 #define _PAGE_BIT_GLOBAL        8       /* Global TLB entry PPro+ */
 #define _PAGE_BIT_UNUSED1       9       /* available for programmer */
 #define _PAGE_BIT_IOMAP         10      /* flag used to indicate IO mapping */
-#define _PAGE_BIT_UNUSED3       11
+#define _PAGE_BIT_HIDDEN        11      /* hidden by kmemcheck */
 #define _PAGE_BIT_PAT_LARGE     12      /* On 2MB or 1GB pages */
 #define _PAGE_BIT_SPECIAL       _PAGE_BIT_UNUSED1
 #define _PAGE_BIT_CPA_TEST      _PAGE_BIT_UNUSED1
@@ -41,13 +41,18 @@
 #define _PAGE_GLOBAL    (_AT(pteval_t, 1) << _PAGE_BIT_GLOBAL)
 #define _PAGE_UNUSED1   (_AT(pteval_t, 1) << _PAGE_BIT_UNUSED1)
 #define _PAGE_IOMAP     (_AT(pteval_t, 1) << _PAGE_BIT_IOMAP)
-#define _PAGE_UNUSED3   (_AT(pteval_t, 1) << _PAGE_BIT_UNUSED3)
 #define _PAGE_PAT       (_AT(pteval_t, 1) << _PAGE_BIT_PAT)
 #define _PAGE_PAT_LARGE (_AT(pteval_t, 1) << _PAGE_BIT_PAT_LARGE)
 #define _PAGE_SPECIAL   (_AT(pteval_t, 1) << _PAGE_BIT_SPECIAL)
 #define _PAGE_CPA_TEST  (_AT(pteval_t, 1) << _PAGE_BIT_CPA_TEST)
 #define __HAVE_ARCH_PTE_SPECIAL
 
+#ifdef CONFIG_KMEMCHECK
+#define _PAGE_HIDDEN    (_AT(pteval_t, 1) << _PAGE_BIT_HIDDEN)
+#else
+#define _PAGE_HIDDEN    (_AT(pteval_t, 0))
+#endif
+
 #if defined(CONFIG_X86_64) || defined(CONFIG_X86_PAE)
 #define _PAGE_NX        (_AT(pteval_t, 1) << _PAGE_BIT_NX)
 #else
diff --git a/arch/x86/include/asm/string_32.h b/arch/x86/include/asm/string_32.h
index 0e0e3ba827f7..c86f452256de 100644
--- a/arch/x86/include/asm/string_32.h
+++ b/arch/x86/include/asm/string_32.h
@@ -177,10 +177,18 @@ static inline void *__memcpy3d(void *to, const void *from, size_t len)
  *      No 3D Now!
  */
 
+#ifndef CONFIG_KMEMCHECK
 #define memcpy(t, f, n)                         \
         (__builtin_constant_p((n))              \
          ? __constant_memcpy((t), (f), (n))     \
          : __memcpy((t), (f), (n)))
+#else
+/*
+ * kmemcheck becomes very happy if we use the REP instructions unconditionally,
+ * because it means that we know both memory operands in advance.
+ */
+#define memcpy(t, f, n) __memcpy((t), (f), (n))
+#endif
 
 #endif
 
diff --git a/arch/x86/include/asm/string_64.h b/arch/x86/include/asm/string_64.h
index 2afe164bf1e6..19e2c468fc2c 100644
--- a/arch/x86/include/asm/string_64.h
+++ b/arch/x86/include/asm/string_64.h
@@ -27,6 +27,7 @@ static __always_inline void *__inline_memcpy(void *to, const void *from, size_t
    function. */
 
 #define __HAVE_ARCH_MEMCPY 1
+#ifndef CONFIG_KMEMCHECK
 #if (__GNUC__ == 4 && __GNUC_MINOR__ >= 3) || __GNUC__ > 4
 extern void *memcpy(void *to, const void *from, size_t len);
 #else
@@ -42,6 +43,13 @@ extern void *__memcpy(void *to, const void *from, size_t len);
         __ret;                                                  \
 })
 #endif
+#else
+/*
+ * kmemcheck becomes very happy if we use the REP instructions unconditionally,
+ * because it means that we know both memory operands in advance.
+ */
+#define memcpy(dst, src, len) __inline_memcpy((dst), (src), (len))
+#endif
 
 #define __HAVE_ARCH_MEMSET
 void *memset(void *s, int c, size_t n);
diff --git a/arch/x86/include/asm/thread_info.h b/arch/x86/include/asm/thread_info.h
index 602c769fc98c..b0783520988b 100644
--- a/arch/x86/include/asm/thread_info.h
+++ b/arch/x86/include/asm/thread_info.h
@@ -154,9 +154,9 @@ struct thread_info {
 
 /* thread information allocation */
 #ifdef CONFIG_DEBUG_STACK_USAGE
-#define THREAD_FLAGS (GFP_KERNEL | __GFP_ZERO)
+#define THREAD_FLAGS (GFP_KERNEL | __GFP_NOTRACK | __GFP_ZERO)
 #else
-#define THREAD_FLAGS GFP_KERNEL
+#define THREAD_FLAGS (GFP_KERNEL | __GFP_NOTRACK)
 #endif
 
 #define __HAVE_ARCH_THREAD_INFO_ALLOCATOR
diff --git a/arch/x86/include/asm/xor.h b/arch/x86/include/asm/xor.h
index 11b3bb86e17b..7fcf6f3dbcc3 100644
--- a/arch/x86/include/asm/xor.h
+++ b/arch/x86/include/asm/xor.h
@@ -1,5 +1,10 @@
+#ifdef CONFIG_KMEMCHECK
+/* kmemcheck doesn't handle MMX/SSE/SSE2 instructions */
+# include <asm-generic/xor.h>
+#else
 #ifdef CONFIG_X86_32
 # include "xor_32.h"
 #else
 # include "xor_64.h"
 #endif
+#endif