arch/x86/include/asm/segment.h - linux - Git at Google

 #ifndef _ASM_X86_SEGMENT_H
 #define _ASM_X86_SEGMENT_H

 #include <linux/const.h>

 /* Constructor for a conventional segment GDT (or LDT) entry */
 /* This is a macro so it can be used in initializers */
 #define GDT_ENTRY(flags, base, limit)			\
 	((((base)  & _AC(0xff000000,ULL)) << (56-24)) |	\
 	 (((flags) & _AC(0x0000f0ff,ULL)) << 40) |	\
 	 (((limit) & _AC(0x000f0000,ULL)) << (48-16)) |	\
 	 (((base)  & _AC(0x00ffffff,ULL)) << 16) |	\
 	 (((limit) & _AC(0x0000ffff,ULL))))

 /* Simple and small GDT entries for booting only */

 #define GDT_ENTRY_BOOT_CS	2
 #define __BOOT_CS		(GDT_ENTRY_BOOT_CS * 8)

 #define GDT_ENTRY_BOOT_DS	(GDT_ENTRY_BOOT_CS + 1)
 #define __BOOT_DS		(GDT_ENTRY_BOOT_DS * 8)

 #define GDT_ENTRY_BOOT_TSS	(GDT_ENTRY_BOOT_CS + 2)
 #define __BOOT_TSS		(GDT_ENTRY_BOOT_TSS * 8)

 #ifdef CONFIG_X86_32
 /*
  * The layout of the per-CPU GDT under Linux:
  *
  *   0 - null
  *   1 - reserved
  *   2 - reserved
  *   3 - reserved
  *
  *   4 - unused			<==== new cacheline
  *   5 - unused
  *
  *  ------- start of TLS (Thread-Local Storage) segments:
  *
  *   6 - TLS segment #1			[ glibc's TLS segment ]
  *   7 - TLS segment #2			[ Wine's %fs Win32 segment ]
  *   8 - TLS segment #3
  *   9 - reserved
  *  10 - reserved
  *  11 - reserved
  *
  *  ------- start of kernel segments:
  *
  *  12 - kernel code segment		<==== new cacheline
  *  13 - kernel data segment
  *  14 - default user CS
  *  15 - default user DS
  *  16 - TSS
  *  17 - LDT
  *  18 - PNPBIOS support (16->32 gate)
  *  19 - PNPBIOS support
  *  20 - PNPBIOS support
  *  21 - PNPBIOS support
  *  22 - PNPBIOS support
  *  23 - APM BIOS support
  *  24 - APM BIOS support
  *  25 - APM BIOS support
  *
  *  26 - ESPFIX small SS
  *  27 - per-cpu			[ offset to per-cpu data area ]
  *  28 - stack_canary-20		[ for stack protector ]
  *  29 - unused
  *  30 - unused
  *  31 - TSS for double fault handler
  */
 #define GDT_ENTRY_TLS_MIN	6
 #define GDT_ENTRY_TLS_MAX 	(GDT_ENTRY_TLS_MIN + GDT_ENTRY_TLS_ENTRIES - 1)

 #define GDT_ENTRY_DEFAULT_USER_CS	14

 #define GDT_ENTRY_DEFAULT_USER_DS	15

 #define GDT_ENTRY_KERNEL_BASE		(12)

 #define GDT_ENTRY_KERNEL_CS		(GDT_ENTRY_KERNEL_BASE+0)

 #define GDT_ENTRY_KERNEL_DS		(GDT_ENTRY_KERNEL_BASE+1)

 #define GDT_ENTRY_TSS			(GDT_ENTRY_KERNEL_BASE+4)
 #define GDT_ENTRY_LDT			(GDT_ENTRY_KERNEL_BASE+5)

 #define GDT_ENTRY_PNPBIOS_BASE		(GDT_ENTRY_KERNEL_BASE+6)
 #define GDT_ENTRY_APMBIOS_BASE		(GDT_ENTRY_KERNEL_BASE+11)

 #define GDT_ENTRY_ESPFIX_SS		(GDT_ENTRY_KERNEL_BASE+14)
 #define __ESPFIX_SS			(GDT_ENTRY_ESPFIX_SS*8)

 #define GDT_ENTRY_PERCPU		(GDT_ENTRY_KERNEL_BASE+15)
 #ifdef CONFIG_SMP
 #define __KERNEL_PERCPU (GDT_ENTRY_PERCPU * 8)
 #else
 #define __KERNEL_PERCPU 0
 #endif

 #define GDT_ENTRY_STACK_CANARY		(GDT_ENTRY_KERNEL_BASE+16)
 #ifdef CONFIG_CC_STACKPROTECTOR
 #define __KERNEL_STACK_CANARY		(GDT_ENTRY_STACK_CANARY*8)
 #else
 #define __KERNEL_STACK_CANARY		0
 #endif

 #define GDT_ENTRY_DOUBLEFAULT_TSS	31

 /*
  * The GDT has 32 entries
  */
 #define GDT_ENTRIES 32

 /* The PnP BIOS entries in the GDT */
 #define GDT_ENTRY_PNPBIOS_CS32		(GDT_ENTRY_PNPBIOS_BASE + 0)
 #define GDT_ENTRY_PNPBIOS_CS16		(GDT_ENTRY_PNPBIOS_BASE + 1)
 #define GDT_ENTRY_PNPBIOS_DS		(GDT_ENTRY_PNPBIOS_BASE + 2)
 #define GDT_ENTRY_PNPBIOS_TS1		(GDT_ENTRY_PNPBIOS_BASE + 3)
 #define GDT_ENTRY_PNPBIOS_TS2		(GDT_ENTRY_PNPBIOS_BASE + 4)

 /* The PnP BIOS selectors */
 #define PNP_CS32   (GDT_ENTRY_PNPBIOS_CS32 * 8)	/* segment for calling fn */
 #define PNP_CS16   (GDT_ENTRY_PNPBIOS_CS16 * 8)	/* code segment for BIOS */
 #define PNP_DS     (GDT_ENTRY_PNPBIOS_DS * 8)	/* data segment for BIOS */
 #define PNP_TS1    (GDT_ENTRY_PNPBIOS_TS1 * 8)	/* transfer data segment */
 #define PNP_TS2    (GDT_ENTRY_PNPBIOS_TS2 * 8)	/* another data segment */

 /* Bottom two bits of selector give the ring privilege level */
 #define SEGMENT_RPL_MASK	0x3
 /* Bit 2 is table indicator (LDT/GDT) */
 #define SEGMENT_TI_MASK		0x4

 /* User mode is privilege level 3 */
 #define USER_RPL		0x3
 /* LDT segment has TI set, GDT has it cleared */
 #define SEGMENT_LDT		0x4
 #define SEGMENT_GDT		0x0

 /*
  * Matching rules for certain types of segments.
  */

 /* Matches PNP_CS32 and PNP_CS16 (they must be consecutive) */
 #define SEGMENT_IS_PNP_CODE(x)   (((x) & 0xf4) == GDT_ENTRY_PNPBIOS_BASE * 8)


 #else
 #include <asm/cache.h>

 #define GDT_ENTRY_KERNEL32_CS 1
 #define GDT_ENTRY_KERNEL_CS 2
 #define GDT_ENTRY_KERNEL_DS 3

 #define __KERNEL32_CS   (GDT_ENTRY_KERNEL32_CS * 8)

 /*
  * we cannot use the same code segment descriptor for user and kernel
  * -- not even in the long flat mode, because of different DPL /kkeil
  * The segment offset needs to contain a RPL. Grr. -AK
  * GDT layout to get 64bit syscall right (sysret hardcodes gdt offsets)
  */
 #define GDT_ENTRY_DEFAULT_USER32_CS 4
 #define GDT_ENTRY_DEFAULT_USER_DS 5
 #define GDT_ENTRY_DEFAULT_USER_CS 6
 #define __USER32_CS   (GDT_ENTRY_DEFAULT_USER32_CS * 8 + 3)
 #define __USER32_DS	__USER_DS

 #define GDT_ENTRY_TSS 8	/* needs two entries */
 #define GDT_ENTRY_LDT 10 /* needs two entries */
 #define GDT_ENTRY_TLS_MIN 12
 #define GDT_ENTRY_TLS_MAX 14

 #define GDT_ENTRY_PER_CPU 15	/* Abused to load per CPU data from limit */
 #define __PER_CPU_SEG	(GDT_ENTRY_PER_CPU * 8 + 3)

 /* TLS indexes for 64bit - hardcoded in arch_prctl */
 #define FS_TLS 0
 #define GS_TLS 1

 #define GS_TLS_SEL ((GDT_ENTRY_TLS_MIN+GS_TLS)*8 + 3)
 #define FS_TLS_SEL ((GDT_ENTRY_TLS_MIN+FS_TLS)*8 + 3)

 #define GDT_ENTRIES 16

 #endif

 #define __KERNEL_CS	(GDT_ENTRY_KERNEL_CS*8)
 #define __KERNEL_DS	(GDT_ENTRY_KERNEL_DS*8)
 #define __USER_DS	(GDT_ENTRY_DEFAULT_USER_DS*8+3)
 #define __USER_CS	(GDT_ENTRY_DEFAULT_USER_CS*8+3)
 #ifndef CONFIG_PARAVIRT
 #define get_kernel_rpl()  0
 #endif

 /* User mode is privilege level 3 */
 #define USER_RPL		0x3
 /* LDT segment has TI set, GDT has it cleared */
 #define SEGMENT_LDT		0x4
 #define SEGMENT_GDT		0x0

 /* Bottom two bits of selector give the ring privilege level */
 #define SEGMENT_RPL_MASK	0x3
 /* Bit 2 is table indicator (LDT/GDT) */
 #define SEGMENT_TI_MASK		0x4

 #define IDT_ENTRIES 256
 #define NUM_EXCEPTION_VECTORS 32
 #define GDT_SIZE (GDT_ENTRIES * 8)
 #define GDT_ENTRY_TLS_ENTRIES 3
 #define TLS_SIZE (GDT_ENTRY_TLS_ENTRIES * 8)

 #ifdef __KERNEL__
 #ifndef __ASSEMBLY__
 extern const char early_idt_handlers[NUM_EXCEPTION_VECTORS][10];
 #endif
 #endif

 #endif /* _ASM_X86_SEGMENT_H */
	#ifndef _ASM_X86_SEGMENT_H
	#define _ASM_X86_SEGMENT_H

	#include <linux/const.h>

	/* Constructor for a conventional segment GDT (or LDT) entry */
	/* This is a macro so it can be used in initializers */
	#define GDT_ENTRY(flags, base, limit) \
	((((base) & _AC(0xff000000,ULL)) << (56-24)) \| \
	(((flags) & _AC(0x0000f0ff,ULL)) << 40) \| \
	(((limit) & _AC(0x000f0000,ULL)) << (48-16)) \| \
	(((base) & _AC(0x00ffffff,ULL)) << 16) \| \
	(((limit) & _AC(0x0000ffff,ULL))))

	/* Simple and small GDT entries for booting only */

	#define GDT_ENTRY_BOOT_CS 2
	#define __BOOT_CS (GDT_ENTRY_BOOT_CS * 8)

	#define GDT_ENTRY_BOOT_DS (GDT_ENTRY_BOOT_CS + 1)
	#define __BOOT_DS (GDT_ENTRY_BOOT_DS * 8)

	#define GDT_ENTRY_BOOT_TSS (GDT_ENTRY_BOOT_CS + 2)
	#define __BOOT_TSS (GDT_ENTRY_BOOT_TSS * 8)

	#ifdef CONFIG_X86_32
	/*
	* The layout of the per-CPU GDT under Linux:
	*
	* 0 - null
	* 1 - reserved
	* 2 - reserved
	* 3 - reserved
	*
	* 4 - unused <==== new cacheline
	* 5 - unused
	*
	* ------- start of TLS (Thread-Local Storage) segments:
	*
	* 6 - TLS segment #1 [ glibc's TLS segment ]
	* 7 - TLS segment #2 [ Wine's %fs Win32 segment ]
	* 8 - TLS segment #3
	* 9 - reserved
	* 10 - reserved
	* 11 - reserved
	*
	* ------- start of kernel segments:
	*
	* 12 - kernel code segment <==== new cacheline
	* 13 - kernel data segment
	* 14 - default user CS
	* 15 - default user DS
	* 16 - TSS
	* 17 - LDT
	* 18 - PNPBIOS support (16->32 gate)
	* 19 - PNPBIOS support
	* 20 - PNPBIOS support
	* 21 - PNPBIOS support
	* 22 - PNPBIOS support
	* 23 - APM BIOS support
	* 24 - APM BIOS support
	* 25 - APM BIOS support
	*
	* 26 - ESPFIX small SS
	* 27 - per-cpu [ offset to per-cpu data area ]
	* 28 - stack_canary-20 [ for stack protector ]
	* 29 - unused
	* 30 - unused
	* 31 - TSS for double fault handler
	*/
	#define GDT_ENTRY_TLS_MIN 6
	#define GDT_ENTRY_TLS_MAX (GDT_ENTRY_TLS_MIN + GDT_ENTRY_TLS_ENTRIES - 1)

	#define GDT_ENTRY_DEFAULT_USER_CS 14

	#define GDT_ENTRY_DEFAULT_USER_DS 15

	#define GDT_ENTRY_KERNEL_BASE (12)

	#define GDT_ENTRY_KERNEL_CS (GDT_ENTRY_KERNEL_BASE+0)

	#define GDT_ENTRY_KERNEL_DS (GDT_ENTRY_KERNEL_BASE+1)

	#define GDT_ENTRY_TSS (GDT_ENTRY_KERNEL_BASE+4)
	#define GDT_ENTRY_LDT (GDT_ENTRY_KERNEL_BASE+5)

	#define GDT_ENTRY_PNPBIOS_BASE (GDT_ENTRY_KERNEL_BASE+6)
	#define GDT_ENTRY_APMBIOS_BASE (GDT_ENTRY_KERNEL_BASE+11)

	#define GDT_ENTRY_ESPFIX_SS (GDT_ENTRY_KERNEL_BASE+14)
	#define __ESPFIX_SS (GDT_ENTRY_ESPFIX_SS*8)

	#define GDT_ENTRY_PERCPU (GDT_ENTRY_KERNEL_BASE+15)
	#ifdef CONFIG_SMP
	#define __KERNEL_PERCPU (GDT_ENTRY_PERCPU * 8)
	#else
	#define __KERNEL_PERCPU 0
	#endif

	#define GDT_ENTRY_STACK_CANARY (GDT_ENTRY_KERNEL_BASE+16)
	#ifdef CONFIG_CC_STACKPROTECTOR
	#define __KERNEL_STACK_CANARY (GDT_ENTRY_STACK_CANARY*8)
	#else
	#define __KERNEL_STACK_CANARY 0
	#endif

	#define GDT_ENTRY_DOUBLEFAULT_TSS 31

	/*
	* The GDT has 32 entries
	*/
	#define GDT_ENTRIES 32

	/* The PnP BIOS entries in the GDT */
	#define GDT_ENTRY_PNPBIOS_CS32 (GDT_ENTRY_PNPBIOS_BASE + 0)
	#define GDT_ENTRY_PNPBIOS_CS16 (GDT_ENTRY_PNPBIOS_BASE + 1)
	#define GDT_ENTRY_PNPBIOS_DS (GDT_ENTRY_PNPBIOS_BASE + 2)
	#define GDT_ENTRY_PNPBIOS_TS1 (GDT_ENTRY_PNPBIOS_BASE + 3)
	#define GDT_ENTRY_PNPBIOS_TS2 (GDT_ENTRY_PNPBIOS_BASE + 4)

	/* The PnP BIOS selectors */
	#define PNP_CS32 (GDT_ENTRY_PNPBIOS_CS32 * 8) /* segment for calling fn */
	#define PNP_CS16 (GDT_ENTRY_PNPBIOS_CS16 * 8) /* code segment for BIOS */
	#define PNP_DS (GDT_ENTRY_PNPBIOS_DS * 8) /* data segment for BIOS */
	#define PNP_TS1 (GDT_ENTRY_PNPBIOS_TS1 * 8) /* transfer data segment */
	#define PNP_TS2 (GDT_ENTRY_PNPBIOS_TS2 * 8) /* another data segment */

	/* Bottom two bits of selector give the ring privilege level */
	#define SEGMENT_RPL_MASK 0x3
	/* Bit 2 is table indicator (LDT/GDT) */
	#define SEGMENT_TI_MASK 0x4

	/* User mode is privilege level 3 */
	#define USER_RPL 0x3
	/* LDT segment has TI set, GDT has it cleared */
	#define SEGMENT_LDT 0x4
	#define SEGMENT_GDT 0x0

	/*
	* Matching rules for certain types of segments.
	*/

	/* Matches PNP_CS32 and PNP_CS16 (they must be consecutive) */
	#define SEGMENT_IS_PNP_CODE(x) (((x) & 0xf4) == GDT_ENTRY_PNPBIOS_BASE * 8)


	#else
	#include <asm/cache.h>

	#define GDT_ENTRY_KERNEL32_CS 1
	#define GDT_ENTRY_KERNEL_CS 2
	#define GDT_ENTRY_KERNEL_DS 3

	#define __KERNEL32_CS (GDT_ENTRY_KERNEL32_CS * 8)

	/*
	* we cannot use the same code segment descriptor for user and kernel
	* -- not even in the long flat mode, because of different DPL /kkeil
	* The segment offset needs to contain a RPL. Grr. -AK
	* GDT layout to get 64bit syscall right (sysret hardcodes gdt offsets)
	*/
	#define GDT_ENTRY_DEFAULT_USER32_CS 4
	#define GDT_ENTRY_DEFAULT_USER_DS 5
	#define GDT_ENTRY_DEFAULT_USER_CS 6
	#define __USER32_CS (GDT_ENTRY_DEFAULT_USER32_CS * 8 + 3)
	#define __USER32_DS __USER_DS

	#define GDT_ENTRY_TSS 8 /* needs two entries */
	#define GDT_ENTRY_LDT 10 /* needs two entries */
	#define GDT_ENTRY_TLS_MIN 12
	#define GDT_ENTRY_TLS_MAX 14

	#define GDT_ENTRY_PER_CPU 15 /* Abused to load per CPU data from limit */
	#define __PER_CPU_SEG (GDT_ENTRY_PER_CPU * 8 + 3)

	/* TLS indexes for 64bit - hardcoded in arch_prctl */
	#define FS_TLS 0
	#define GS_TLS 1

	#define GS_TLS_SEL ((GDT_ENTRY_TLS_MIN+GS_TLS)*8 + 3)
	#define FS_TLS_SEL ((GDT_ENTRY_TLS_MIN+FS_TLS)*8 + 3)

	#define GDT_ENTRIES 16

	#endif

	#define __KERNEL_CS (GDT_ENTRY_KERNEL_CS*8)
	#define __KERNEL_DS (GDT_ENTRY_KERNEL_DS*8)
	#define __USER_DS (GDT_ENTRY_DEFAULT_USER_DS*8+3)
	#define __USER_CS (GDT_ENTRY_DEFAULT_USER_CS*8+3)
	#ifndef CONFIG_PARAVIRT
	#define get_kernel_rpl() 0
	#endif

	/* User mode is privilege level 3 */
	#define USER_RPL 0x3
	/* LDT segment has TI set, GDT has it cleared */
	#define SEGMENT_LDT 0x4
	#define SEGMENT_GDT 0x0

	/* Bottom two bits of selector give the ring privilege level */
	#define SEGMENT_RPL_MASK 0x3
	/* Bit 2 is table indicator (LDT/GDT) */
	#define SEGMENT_TI_MASK 0x4

	#define IDT_ENTRIES 256
	#define NUM_EXCEPTION_VECTORS 32
	#define GDT_SIZE (GDT_ENTRIES * 8)
	#define GDT_ENTRY_TLS_ENTRIES 3
	#define TLS_SIZE (GDT_ENTRY_TLS_ENTRIES * 8)

	#ifdef __KERNEL__
	#ifndef __ASSEMBLY__
	extern const char early_idt_handlers[NUM_EXCEPTION_VECTORS][10];
	#endif
	#endif

	#endif /* _ASM_X86_SEGMENT_H */