pack SegmentDescriptor to eliminate any alignment ambiguity

This commit is contained in:
Chris Eagle 2016-03-28 09:29:55 -07:00
parent 56d70845da
commit 3ca072e0de

View file

@ -26,42 +26,44 @@ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
#include <stdlib.h>
#include <unistd.h>
#pragma pack(push, 1)
struct SegmentDescriptor {
union {
struct {
# if __BYTE_ORDER == __LITTLE_ENDIAN
#if __BYTE_ORDER == __LITTLE_ENDIAN
unsigned short limit0;
unsigned short base0;
unsigned char base1;
unsigned int type:4;
unsigned int system:1; /* S flag */
unsigned int dpl:2;
unsigned int present:1; /* P flag */
unsigned int limit1:4;
unsigned int avail:1;
unsigned int is_64_code:1; /* L flag */
unsigned int db:1; /* DB flag */
unsigned int granularity:1; /* G flag */
unsigned char type:4;
unsigned char system:1; /* S flag */
unsigned char dpl:2;
unsigned char present:1; /* P flag */
unsigned char limit1:4;
unsigned char avail:1;
unsigned char is_64_code:1; /* L flag */
unsigned char db:1; /* DB flag */
unsigned char granularity:1; /* G flag */
unsigned char base2;
# else
#else
unsigned char base2;
unsigned int granularity:1; /* G flag */
unsigned int db:1; /* DB flag */
unsigned int is_64_code:1; /* L flag */
unsigned int avail:1;
unsigned int limit1:4;
unsigned int present:1; /* P flag */
unsigned int dpl:2;
unsigned int system:1; /* S flag */
unsigned int type:4;
unsigned char granularity:1; /* G flag */
unsigned char db:1; /* DB flag */
unsigned char is_64_code:1; /* L flag */
unsigned char avail:1;
unsigned char limit1:4;
unsigned char present:1; /* P flag */
unsigned char dpl:2;
unsigned char system:1; /* S flag */
unsigned char type:4;
unsigned char base1;
unsigned short base0;
unsigned short limit0;
# endif
#endif
};
uint64_t desc;
};
};
#pragma pack(pop)
#define SEGBASE(d) ((uint32_t)((((d).desc >> 16) & 0xffffff) | (((d).desc >> 32) & 0xff000000)))
#define SEGLIMIT(d) ((d).limit0 | (((unsigned int)(d).limit1) << 16))