freebsd-skq/sys/amd64/include/segments.h
kib 253f7779bc Save and restore segment registers on amd64 when entering and leaving
the kernel on amd64. Fill and read segment registers for mcontext and
signals. Handle traps caused by restoration of the
invalidated selectors.

Implement user-mode creation and manipulation of the process-specific
LDT descriptors for amd64, see sysarch(2).

Implement support for TSS i/o port access permission bitmap for amd64.

Context-switch LDT and TSS. Do not save and restore segment registers on
the context switch, that is handled by kernel enter/leave trampolines
now. Remove segment restore code from the signal trampolines for
freebsd/amd64, freebsd/ia32 and linux/i386 for the same reason.

Implement amd64-specific compat shims for sysarch.

Linuxolator (temporary ?) switched to use gsbase for thread_area pointer.

TODO:
Currently, gdb is not adapted to show segment registers from struct reg.
Also, no machine-depended ptrace command is added to set segment
registers for debugged process.

In collaboration with:	pho
Discussed with:	peter
Reviewed by:	jhb
Linuxolator tested by:	dchagin
2009-04-01 13:09:26 +00:00

248 lines
9.8 KiB
C

/*-
* Copyright (c) 1989, 1990 William F. Jolitz
* Copyright (c) 1990 The Regents of the University of California.
* All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* William Jolitz.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* from: @(#)segments.h 7.1 (Berkeley) 5/9/91
* $FreeBSD$
*/
#ifndef _MACHINE_SEGMENTS_H_
#define _MACHINE_SEGMENTS_H_
/*
* AMD64 Segmentation Data Structures and definitions
*/
/*
* Selectors
*/
#define SEL_RPL_MASK 3 /* requester priv level */
#define ISPL(s) ((s)&3) /* what is the priority level of a selector */
#define SEL_KPL 0 /* kernel priority level */
#define SEL_UPL 3 /* user priority level */
#define ISLDT(s) ((s)&SEL_LDT) /* is it local or global */
#define SEL_LDT 4 /* local descriptor table */
#define IDXSEL(s) (((s)>>3) & 0x1fff) /* index of selector */
#define LSEL(s,r) (((s)<<3) | SEL_LDT | r) /* a local selector */
#define GSEL(s,r) (((s)<<3) | r) /* a global selector */
/*
* User segment descriptors (%cs, %ds etc for compatability apps. 64 bit wide)
* For long-mode apps, %cs only has the conforming bit in sd_type, the sd_dpl,
* sd_p, sd_l and sd_def32 which must be zero). %ds only has sd_p.
*/
struct user_segment_descriptor {
u_int64_t sd_lolimit:16; /* segment extent (lsb) */
u_int64_t sd_lobase:24; /* segment base address (lsb) */
u_int64_t sd_type:5; /* segment type */
u_int64_t sd_dpl:2; /* segment descriptor priority level */
u_int64_t sd_p:1; /* segment descriptor present */
u_int64_t sd_hilimit:4; /* segment extent (msb) */
u_int64_t sd_xx:1; /* unused */
u_int64_t sd_long:1; /* long mode (cs only) */
u_int64_t sd_def32:1; /* default 32 vs 16 bit size */
u_int64_t sd_gran:1; /* limit granularity (byte/page units)*/
u_int64_t sd_hibase:8; /* segment base address (msb) */
} __packed;
/*
* System segment descriptors (128 bit wide)
*/
struct system_segment_descriptor {
u_int64_t sd_lolimit:16; /* segment extent (lsb) */
u_int64_t sd_lobase:24; /* segment base address (lsb) */
u_int64_t sd_type:5; /* segment type */
u_int64_t sd_dpl:2; /* segment descriptor priority level */
u_int64_t sd_p:1; /* segment descriptor present */
u_int64_t sd_hilimit:4; /* segment extent (msb) */
u_int64_t sd_xx0:3; /* unused */
u_int64_t sd_gran:1; /* limit granularity (byte/page units)*/
u_int64_t sd_hibase:40 __packed;/* segment base address (msb) */
u_int64_t sd_xx1:8;
u_int64_t sd_mbz:5; /* MUST be zero */
u_int64_t sd_xx2:19;
} __packed;
/*
* Gate descriptors (e.g. indirect descriptors, trap, interrupt etc. 128 bit)
* Only interrupt and trap gates have gd_ist.
*/
struct gate_descriptor {
u_int64_t gd_looffset:16; /* gate offset (lsb) */
u_int64_t gd_selector:16; /* gate segment selector */
u_int64_t gd_ist:3; /* IST table index */
u_int64_t gd_xx:5; /* unused */
u_int64_t gd_type:5; /* segment type */
u_int64_t gd_dpl:2; /* segment descriptor priority level */
u_int64_t gd_p:1; /* segment descriptor present */
u_int64_t gd_hioffset:48 __packed; /* gate offset (msb) */
u_int64_t sd_xx1:32;
} __packed;
/*
* Generic descriptor
*/
union descriptor {
struct user_segment_descriptor sd;
struct gate_descriptor gd;
};
/* system segments and gate types */
#define SDT_SYSNULL 0 /* system null */
#define SDT_SYS286TSS 1 /* system 286 TSS available */
#define SDT_SYSLDT 2 /* system 64 bit local descriptor table */
#define SDT_SYS286BSY 3 /* system 286 TSS busy */
#define SDT_SYS286CGT 4 /* system 286 call gate */
#define SDT_SYSTASKGT 5 /* system task gate */
#define SDT_SYS286IGT 6 /* system 286 interrupt gate */
#define SDT_SYS286TGT 7 /* system 286 trap gate */
#define SDT_SYSNULL2 8 /* system null again */
#define SDT_SYSTSS 9 /* system available 64 bit TSS */
#define SDT_SYSNULL3 10 /* system null again */
#define SDT_SYSBSY 11 /* system busy 64 bit TSS */
#define SDT_SYSCGT 12 /* system 64 bit call gate */
#define SDT_SYSNULL4 13 /* system null again */
#define SDT_SYSIGT 14 /* system 64 bit interrupt gate */
#define SDT_SYSTGT 15 /* system 64 bit trap gate */
/* memory segment types */
#define SDT_MEMRO 16 /* memory read only */
#define SDT_MEMROA 17 /* memory read only accessed */
#define SDT_MEMRW 18 /* memory read write */
#define SDT_MEMRWA 19 /* memory read write accessed */
#define SDT_MEMROD 20 /* memory read only expand dwn limit */
#define SDT_MEMRODA 21 /* memory read only expand dwn limit accessed */
#define SDT_MEMRWD 22 /* memory read write expand dwn limit */
#define SDT_MEMRWDA 23 /* memory read write expand dwn limit accessed */
#define SDT_MEME 24 /* memory execute only */
#define SDT_MEMEA 25 /* memory execute only accessed */
#define SDT_MEMER 26 /* memory execute read */
#define SDT_MEMERA 27 /* memory execute read accessed */
#define SDT_MEMEC 28 /* memory execute only conforming */
#define SDT_MEMEAC 29 /* memory execute only accessed conforming */
#define SDT_MEMERC 30 /* memory execute read conforming */
#define SDT_MEMERAC 31 /* memory execute read accessed conforming */
/*
* Software definitions are in this convenient format,
* which are translated into inconvenient segment descriptors
* when needed to be used by the 386 hardware
*/
struct soft_segment_descriptor {
unsigned long ssd_base; /* segment base address */
unsigned long ssd_limit; /* segment extent */
unsigned long ssd_type:5; /* segment type */
unsigned long ssd_dpl:2; /* segment descriptor priority level */
unsigned long ssd_p:1; /* segment descriptor present */
unsigned long ssd_long:1; /* long mode (for %cs) */
unsigned long ssd_def32:1; /* default 32 vs 16 bit size */
unsigned long ssd_gran:1; /* limit granularity (byte/page units)*/
} __packed;
/*
* region descriptors, used to load gdt/idt tables before segments yet exist.
*/
struct region_descriptor {
unsigned long rd_limit:16; /* segment extent */
unsigned long rd_base:64 __packed; /* base address */
} __packed;
/*
* Size of IDT table
*/
#define NIDT 256 /* 32 reserved, 16 h/w, 0 s/w, linux's 0x80 */
#define NRSVIDT 32 /* reserved entries for cpu exceptions */
/*
* Entries in the Interrupt Descriptor Table (IDT)
*/
#define IDT_DE 0 /* #DE: Divide Error */
#define IDT_DB 1 /* #DB: Debug */
#define IDT_NMI 2 /* Nonmaskable External Interrupt */
#define IDT_BP 3 /* #BP: Breakpoint */
#define IDT_OF 4 /* #OF: Overflow */
#define IDT_BR 5 /* #BR: Bound Range Exceeded */
#define IDT_UD 6 /* #UD: Undefined/Invalid Opcode */
#define IDT_NM 7 /* #NM: No Math Coprocessor */
#define IDT_DF 8 /* #DF: Double Fault */
#define IDT_FPUGP 9 /* Coprocessor Segment Overrun */
#define IDT_TS 10 /* #TS: Invalid TSS */
#define IDT_NP 11 /* #NP: Segment Not Present */
#define IDT_SS 12 /* #SS: Stack Segment Fault */
#define IDT_GP 13 /* #GP: General Protection Fault */
#define IDT_PF 14 /* #PF: Page Fault */
#define IDT_MF 16 /* #MF: FPU Floating-Point Error */
#define IDT_AC 17 /* #AC: Alignment Check */
#define IDT_MC 18 /* #MC: Machine Check */
#define IDT_XF 19 /* #XF: SIMD Floating-Point Exception */
#define IDT_IO_INTS NRSVIDT /* Base of IDT entries for I/O interrupts. */
#define IDT_SYSCALL 0x80 /* System Call Interrupt Vector */
/*
* Entries in the Global Descriptor Table (GDT)
*/
#define GNULL_SEL 0 /* Null Descriptor */
#define GNULL2_SEL 1 /* Null Descriptor */
#define GUFS32_SEL 2 /* User 32 bit %fs Descriptor */
#define GUGS32_SEL 3 /* User 32 bit %gs Descriptor */
#define GCODE_SEL 4 /* Kernel Code Descriptor */
#define GDATA_SEL 5 /* Kernel Data Descriptor */
#define GUCODE32_SEL 6 /* User 32 bit code Descriptor */
#define GUDATA_SEL 7 /* User 32/64 bit Data Descriptor */
#define GUCODE_SEL 8 /* User 64 bit Code Descriptor */
#define GPROC0_SEL 9 /* TSS for entering kernel etc */
/* slot 10 is second half of GPROC0_SEL */
#define GUSERLDT_SEL 11 /* LDT */
/* slot 11 is second half of GUSERLDT_SEL */
#define NGDT 13
#ifdef _KERNEL
extern struct user_segment_descriptor gdt[];
extern struct soft_segment_descriptor gdt_segs[];
extern struct gate_descriptor *idt;
extern struct region_descriptor r_gdt, r_idt;
void lgdt(struct region_descriptor *rdp);
void sdtossd(struct user_segment_descriptor *sdp,
struct soft_segment_descriptor *ssdp);
void ssdtosd(struct soft_segment_descriptor *ssdp,
struct user_segment_descriptor *sdp);
void ssdtosyssd(struct soft_segment_descriptor *ssdp,
struct system_segment_descriptor *sdp);
void update_gdt_gsbase(struct thread *td, uint32_t base);
void update_gdt_fsbase(struct thread *td, uint32_t base);
#endif /* _KERNEL */
#endif /* !_MACHINE_SEGMENTS_H_ */