File dosfstools-2.11-unaligned.patch of Package dosfstools

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File dosfstools-2.11-unaligned.patch of Package dosfstools

---
 dosfsck/boot.c |  131 ++++++++++++++++++++++++++++++++++++++++++++++++++++-----
 1 file changed, 120 insertions(+), 11 deletions(-)

--- a/dosfsck/boot.c
+++ b/dosfsck/boot.c
@@ -34,18 +34,127 @@ static struct {
     { 0xff, "5.25\" 320k floppy 2s/40tr/8sec" },
 };
 
-#if defined __alpha || defined __ia64__ || defined __s390x__ || defined __x86_64__ || defined __ppc64__
-/* Unaligned fields must first be copied byte-wise */
-#define GET_UNALIGNED_W(f)			\
-    ({						\
-	unsigned short __v;			\
-	memcpy( &__v, &f, sizeof(__v) );	\
-	CF_LE_W( *(unsigned short *)&f );	\
-    })
-#else
-#define GET_UNALIGNED_W(f) CF_LE_W( *(unsigned short *)&f )
-#endif
 
+/*
+ * For the benefit of those who are trying to port Linux to another
+ * architecture, here are some C-language equivalents.
+ *
+ * This is based almost entirely upon Richard Henderson's
+ * asm-alpha/unaligned.h implementation.  Some comments were
+ * taken from David Mosberger's asm-ia64/unaligned.h header.
+ */
+
+#include <linux/types.h>
+
+/*
+ * The main single-value unaligned transfer routines.
+ */
+#define get_unaligned(ptr) \
+	__get_unaligned((ptr), sizeof(*(ptr)))
+#define put_unaligned(x,ptr) \
+	__put_unaligned((__u64)(x), (ptr), sizeof(*(ptr)))
+
+/*
+ * This function doesn't actually exist.  The idea is that when
+ * someone uses the macros below with an unsupported size (datatype),
+ * the linker will alert us to the problem via an unresolved reference
+ * error.
+ */
+extern void bad_unaligned_access_length(void) __attribute__((noreturn));
+
+struct __una_u64 { __u64 x __attribute__((packed)); };
+struct __una_u32 { __u32 x __attribute__((packed)); };
+struct __una_u16 { __u16 x __attribute__((packed)); };
+
+/*
+ * Elemental unaligned loads
+ */
+
+static inline __u64 __uldq(const __u64 *addr)
+{
+	const struct __una_u64 *ptr = (const struct __una_u64 *) addr;
+	return ptr->x;
+}
+
+static inline __u32 __uldl(const __u32 *addr)
+{
+	const struct __una_u32 *ptr = (const struct __una_u32 *) addr;
+	return ptr->x;
+}
+
+static inline __u16 __uldw(const __u16 *addr)
+{
+	const struct __una_u16 *ptr = (const struct __una_u16 *) addr;
+	return ptr->x;
+}
+
+/*
+ * Elemental unaligned stores
+ */
+
+static inline void __ustq(__u64 val, __u64 *addr)
+{
+	struct __una_u64 *ptr = (struct __una_u64 *) addr;
+	ptr->x = val;
+}
+
+static inline void __ustl(__u32 val, __u32 *addr)
+{
+	struct __una_u32 *ptr = (struct __una_u32 *) addr;
+	ptr->x = val;
+}
+
+static inline void __ustw(__u16 val, __u16 *addr)
+{
+	struct __una_u16 *ptr = (struct __una_u16 *) addr;
+	ptr->x = val;
+}
+
+#define __get_unaligned(ptr, size) ({		\
+	const void *__gu_p = ptr;		\
+	__u64 val;				\
+	switch (size) {				\
+	case 1:					\
+		val = *(const __u8 *)__gu_p;	\
+		break;				\
+	case 2:					\
+		val = __uldw(__gu_p);		\
+		break;				\
+	case 4:					\
+		val = __uldl(__gu_p);		\
+		break;				\
+	case 8:					\
+		val = __uldq(__gu_p);		\
+		break;				\
+	default:				\
+		bad_unaligned_access_length();	\
+	};					\
+	(__typeof__(*(ptr)))val;		\
+})
+
+#define __put_unaligned(val, ptr, size)		\
+do {						\
+	void *__gu_p = ptr;			\
+	switch (size) {				\
+	case 1:					\
+		*(__u8 *)__gu_p = val;		\
+	        break;				\
+	case 2:					\
+		__ustw(val, __gu_p);		\
+		break;				\
+	case 4:					\
+		__ustl(val, __gu_p);		\
+		break;				\
+	case 8:					\
+		__ustq(val, __gu_p);		\
+		break;				\
+	default:				\
+	    	bad_unaligned_access_length();	\
+	};					\
+} while(0)
+
+
+#define GET_UNALIGNED_W(f) CF_LE_W( get_unaligned ((unsigned short *)&f))
 
 static char *get_media_descr( unsigned char media )
 {

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File dosfstools-2.11-unaligned.patch of Package dosfstools

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