dosfstools/dosfstools-2.11-unaligned.patch

146 lines
3.5 KiB
Diff

---
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 )
{