3 files changed, 57 insertions, 0 deletions
diff --git a/arch/x86/include/asm/kvm_para.h b/arch/x86/include/asm/kvm_para.h
index 734c3767cfa..183922e13de 100644
--- a/arch/x86/include/asm/kvm_para.h
+++ b/arch/x86/include/asm/kvm_para.h
@@ -170,6 +170,9 @@ static inline int kvm_para_available(void)
 	unsigned int eax, ebx, ecx, edx;
 	char signature[13];
 
+	if (boot_cpu_data.cpuid_level < 0)
+		return 0;	/* So we don't blow up on old processors */
+
 	cpuid(KVM_CPUID_SIGNATURE, &eax, &ebx, &ecx, &edx);
 	memcpy(signature + 0, &ebx, 4);
 	memcpy(signature + 4, &ecx, 4);
diff --git a/arch/x86/include/asm/stat.h b/arch/x86/include/asm/stat.h
index e0b1d9bbcbc..7b3ddc34858 100644
--- a/arch/x86/include/asm/stat.h
+++ b/arch/x86/include/asm/stat.h
@@ -25,6 +25,12 @@ struct stat {
 	unsigned long  __unused5;
 };
 
+/* We don't need to memset the whole thing just to initialize the padding */
+#define INIT_STRUCT_STAT_PADDING(st) do {	\
+	st.__unused4 = 0;			\
+	st.__unused5 = 0;			\
+} while (0)
+
 #define STAT64_HAS_BROKEN_ST_INO	1
 
 /* This matches struct stat64 in glibc2.1, hence the absolutely
@@ -63,6 +69,12 @@ struct stat64 {
 	unsigned long long	st_ino;
 };
 
+/* We don't need to memset the whole thing just to initialize the padding */
+#define INIT_STRUCT_STAT64_PADDING(st) do {		\
+	memset(&st.__pad0, 0, sizeof(st.__pad0));	\
+	memset(&st.__pad3, 0, sizeof(st.__pad3));	\
+} while (0)
+
 #else /* __i386__ */
 
 struct stat {
@@ -87,6 +99,15 @@ struct stat {
 	unsigned long   st_ctime_nsec;
 	long		__unused[3];
 };
+
+/* We don't need to memset the whole thing just to initialize the padding */
+#define INIT_STRUCT_STAT_PADDING(st) do {	\
+	st.__pad0 = 0;				\
+	st.__unused[0] = 0;			\
+	st.__unused[1] = 0;			\
+	st.__unused[2] = 0;			\
+} while (0)
+
 #endif
 
 /* for 32bit emulation and 32 bit kernels */
diff --git a/arch/x86/include/asm/word-at-a-time.h b/arch/x86/include/asm/word-at-a-time.h
index 6fe6767b712..e58f03b206c 100644
--- a/arch/x86/include/asm/word-at-a-time.h
+++ b/arch/x86/include/asm/word-at-a-time.h
@@ -43,4 +43,37 @@ static inline unsigned long has_zero(unsigned long a)
 	return ((a - REPEAT_BYTE(0x01)) & ~a) & REPEAT_BYTE(0x80);
 }
 
+/*
+ * Load an unaligned word from kernel space.
+ *
+ * In the (very unlikely) case of the word being a page-crosser
+ * and the next page not being mapped, take the exception and
+ * return zeroes in the non-existing part.
+ */
+static inline unsigned long load_unaligned_zeropad(const void *addr)
+{
+	unsigned long ret, dummy;
+
+	asm(
+		"1:\tmov %2,%0\n"
+		"2:\n"
+		".section .fixup,\"ax\"\n"
+		"3:\t"
+		"lea %2,%1\n\t"
+		"and %3,%1\n\t"
+		"mov (%1),%0\n\t"
+		"leal %2,%%ecx\n\t"
+		"andl %4,%%ecx\n\t"
+		"shll $3,%%ecx\n\t"
+		"shr %%cl,%0\n\t"
+		"jmp 2b\n"
+		".previous\n"
+		_ASM_EXTABLE(1b, 3b)
+		:"=&r" (ret),"=&c" (dummy)
+		:"m" (*(unsigned long *)addr),
+		 "i" (-sizeof(unsigned long)),
+		 "i" (sizeof(unsigned long)-1));
+	return ret;
+}
+
 #endif /* _ASM_WORD_AT_A_TIME_H */