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Eliminate soft segment descriptors; instead use a functional interface for

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creating segment descriptors.  Add the duplicate system call gate used by
BSD/OS 2.0 executables.  Prototype setsegment() and setgate(), and fix a bogon
caught by this.
This commit is contained in:
mycroft 1995-10-09 06:34:11 +00:00
parent b407d48e85
commit 8096b83664
5 changed files with 64 additions and 206 deletions
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222
sys/arch/i386/i386/machdep.c
View File

@ -1,4 +1,4 @@
/* $NetBSD: machdep.c,v 1.173 1995/10/07 06:25:40 mycroft Exp $ */
/* $NetBSD: machdep.c,v 1.174 1995/10/09 06:34:11 mycroft Exp $ */
/*-
* Copyright (c) 1993, 1994, 1995 Charles M. Hannum. All rights reserved.
@ -939,136 +939,41 @@ struct i386tss tss;
extern struct user *proc0paddr;
/* software prototypes -- in more palatable form */
struct soft_segment_descriptor gdt_segs[] = {
/* Null descriptor */
{ 0x0, /* segment base address */
0x0, /* length */
0, /* segment type */
0, /* segment descriptor privilege level */
0, /* segment descriptor present */
0, 0,
0, /* default 32 vs 16 bit size */
0 /* limit granularity (byte/page units) */ },
/* Kernel code descriptor */
{ 0x0, /* segment base address */
0xfffff, /* length - all address space */
SDT_MEMERA, /* segment type */
SEL_KPL, /* segment descriptor privilege level */
1, /* segment descriptor present */
0, 0,
1, /* default 32 vs 16 bit size */
1 /* limit granularity (byte/page units) */ },
/* Kernel data descriptor */
{ 0x0, /* segment base address */
0xfffff, /* length - all address space */
SDT_MEMRWA, /* segment type */
SEL_KPL, /* segment descriptor privilege level */
1, /* segment descriptor present */
0, 0,
1, /* default 32 vs 16 bit size */
1 /* limit granularity (byte/page units) */ },
/* LDT descriptor */
{ (int) ldt, /* segment base address */
sizeof(ldt)-1, /* length - all address space */
SDT_SYSLDT, /* segment type */
0, /* segment descriptor privilege level */
1, /* segment descriptor present */
0, 0,
0, /* unused - default 32 vs 16 bit size */
0 /* limit granularity (byte/page units) */ },
/* User code descriptor */
{ 0x0, /* segment base address */
0xfffff, /* length - all address space */
SDT_MEMERA, /* segment type */
SEL_UPL, /* segment descriptor privilege level */
1, /* segment descriptor present */
0, 0,
1, /* default 32 vs 16 bit size */
1 /* limit granularity (byte/page units) */ },
/* User data descriptor */
{ 0x0, /* segment base address */
0xfffff, /* length - all address space */
SDT_MEMRWA, /* segment type */
SEL_UPL, /* segment descriptor privilege level */
1, /* segment descriptor present */
0, 0,
1, /* default 32 vs 16 bit size */
1 /* limit granularity (byte/page units) */ },
/* Proc 0 TSS descriptor */
{ (int) USRSTACK, /* segment base address */
sizeof(tss)-1, /* length - all address space */
SDT_SYS386TSS, /* segment type */
SEL_KPL, /* segment descriptor privilege level */
1, /* segment descriptor present */
0, 0,
0, /* unused - default 32 vs 16 bit size */
0 /* limit granularity (byte/page units) */ },
/* User LDT descriptor per process */
{ (int) ldt, /* segment base address */
(512 * sizeof(union descriptor)-1), /* length */
SDT_SYSLDT, /* segment type */
0, /* segment descriptor privilege level */
1, /* segment descriptor present */
0, 0,
0, /* unused - default 32 vs 16 bit size */
0 /* limit granularity (byte/page units) */ },
};
struct soft_segment_descriptor ldt_segs[] = {
/* Null descriptor - overwritten by call gate */
{ 0x0, /* segment base address */
0x0, /* length */
0, /* segment type */
0, /* segment descriptor privilege level */
0, /* segment descriptor present */
0, 0,
0, /* default 32 vs 16 bit size */
0 /* limit granularity (byte/page units) */ },
/* Null descriptor - overwritten by call gate */
{ 0x0, /* segment base address */
0x0, /* length */
0, /* segment type */
0, /* segment descriptor privilege level */
0, /* segment descriptor present */
0, 0,
0, /* default 32 vs 16 bit size */
0 /* limit granularity (byte/page units) */ },
/* User code descriptor */
{ 0x0, /* segment base address */
0xfffff, /* length - all address space */
SDT_MEMERA, /* segment type */
SEL_UPL, /* segment descriptor privilege level */
1, /* segment descriptor present */
0, 0,
1, /* default 32 vs 16 bit size */
1 /* limit granularity (byte/page units) */ },
/* User data descriptor */
{ 0x0, /* segment base address */
0xfffff, /* length - all address space */
SDT_MEMRWA, /* segment type */
SEL_UPL, /* segment descriptor privilege level */
1, /* segment descriptor present */
0, 0,
1, /* default 32 vs 16 bit size */
1 /* limit granularity (byte/page units) */ },
};
void
setgate(gdp, func, args, typ, dpl)
struct gate_descriptor *gdp;
void *func;
int args, typ, dpl;
setsegment(sd, base, limit, type, dpl, def32, gran)
struct segment_descriptor *sd;
void *base;
size_t limit;
int type, dpl, def32, gran;
{
gdp->gd_looffset = (int)func;
gdp->gd_selector = GSEL(GCODE_SEL, SEL_KPL);
gdp->gd_stkcpy = args;
gdp->gd_xx = 0;
gdp->gd_type = typ;
gdp->gd_dpl = dpl;
gdp->gd_p = 1;
gdp->gd_hioffset = (int)func >> 16;
sd->sd_lolimit = (int)limit;
sd->sd_lobase = (int)base;
sd->sd_type = type;
sd->sd_dpl = dpl;
sd->sd_p = 1;
sd->sd_hilimit = (int)limit >> 16;
sd->sd_xx = 0;
sd->sd_def32 = def32;
sd->sd_gran = gran;
sd->sd_hibase = (int)base >> 24;
}
void
setgate(gd, func, args, type, dpl)
struct gate_descriptor *gd;
void *func;
int args, type, dpl;
{
gd->gd_looffset = (int)func;
gd->gd_selector = GSEL(GCODE_SEL, SEL_KPL);
gd->gd_stkcpy = args;
gd->gd_xx = 0;
gd->gd_type = type;
gd->gd_dpl = dpl;
gd->gd_p = 1;
gd->gd_hioffset = (int)func >> 16;
}
#define IDTVEC(name) __CONCAT(X, name)
@ -1079,38 +984,6 @@ extern IDTVEC(div), IDTVEC(dbg), IDTVEC(nmi), IDTVEC(bpt),
IDTVEC(fpu), IDTVEC(align),
IDTVEC(syscall), IDTVEC(osyscall);
void
sdtossd(sd, ssd)
struct segment_descriptor *sd;
struct soft_segment_descriptor *ssd;
{
ssd->ssd_base = (sd->sd_hibase << 24) | sd->sd_lobase;
ssd->ssd_limit = (sd->sd_hilimit << 16) | sd->sd_lolimit;
ssd->ssd_type = sd->sd_type;
ssd->ssd_dpl = sd->sd_dpl;
ssd->ssd_p = sd->sd_p;
ssd->ssd_def32 = sd->sd_def32;
ssd->ssd_gran = sd->sd_gran;
}
void
ssdtosd(ssd, sd)
struct soft_segment_descriptor *ssd;
struct segment_descriptor *sd;
{
sd->sd_lobase = ssd->ssd_base;
sd->sd_hibase = ssd->ssd_base >> 24;
sd->sd_lolimit = ssd->ssd_limit;
sd->sd_hilimit = ssd->ssd_limit >> 16;
sd->sd_type = ssd->ssd_type;
sd->sd_dpl = ssd->ssd_dpl;
sd->sd_p = ssd->ssd_p;
sd->sd_def32 = ssd->ssd_def32;
sd->sd_gran = ssd->ssd_gran;
}
void
init386(first_avail)
vm_offset_t first_avail;
@ -1134,23 +1007,24 @@ init386(first_avail)
pcb->pcb_tss.tss_ss0 = GSEL(GDATA_SEL, SEL_KPL);
pcb->pcb_tss.tss_ioopt = sizeof(struct i386tss) << 16;
/* make gdt gates memory segments */
setsegment(&gdt[GCODE_SEL].sd, 0, 0xfffff, SDT_MEMERA, SEL_KPL, 1, 1);
setsegment(&gdt[GDATA_SEL].sd, 0, 0xfffff, SDT_MEMRWA, SEL_KPL, 1, 1);
setsegment(&gdt[GLDT_SEL].sd, ldt, sizeof(ldt) - 1, SDT_SYSLDT, SEL_KPL,
0, 0);
setsegment(&gdt[GUCODE_SEL].sd, 0, i386_btop(VM_MAXUSER_ADDRESS) - 1,
SDT_MEMERA, SEL_UPL, 1, 1);
setsegment(&gdt[GUDATA_SEL].sd, 0, i386_btop(VM_MAXUSER_ADDRESS) - 1,
SDT_MEMRWA, SEL_UPL, 1, 1);
setsegment(&gdt[GPROC0_SEL].sd, (void *)USRSTACK, sizeof(tss) - 1,
SDT_SYS386TSS, SEL_KPL, 0, 0);
#ifndef LKM
/* set code segment limit to end of kernel text */
gdt_segs[GCODE_SEL].ssd_limit = i386_btop(i386_round_page(&etext)) - 1;
#endif
for (x = 0; x < NGDT; x++)
ssdtosd(&gdt_segs[x], &gdt[x].sd);
/* make ldt memory segments */
ldt_segs[LUCODE_SEL].ssd_limit = i386_btop(VM_MAXUSER_ADDRESS) - 1;
ldt_segs[LUDATA_SEL].ssd_limit = i386_btop(VM_MAXUSER_ADDRESS) - 1;
for (x = 0; x < NLDT; x++)
ssdtosd(&ldt_segs[x], &ldt[x].sd);
/* Set up the old-style call gate descriptor for system calls. */
/* make ldt gates memory segments */
setgate(&ldt[LSYS5CALLS_SEL].gd, &IDTVEC(osyscall), 1, SDT_SYS386CGT,
SEL_UPL);
ldt[LUCODE_SEL] = gdt[GUCODE_SEL];
ldt[LUDATA_SEL] = gdt[GUDATA_SEL];
ldt[LBSDICALLS_SEL] = ldt[LSYS5CALLS_SEL];
/* exceptions */
for (x = 0; x < NIDT; x++)

7
sys/arch/i386/i386/sys_machdep.c
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@ -1,4 +1,4 @@
/* $NetBSD: sys_machdep.c,v 1.21 1995/10/09 04:00:24 thorpej Exp $ */
/* $NetBSD: sys_machdep.c,v 1.22 1995/10/09 06:34:25 mycroft Exp $ */
/*-
* Copyright (c) 1995 Charles M. Hannum. All rights reserved.
@ -231,9 +231,8 @@ i386_set_ldt(p, args, retval)
}
bzero((caddr_t)new_ldt + oldlen, len - oldlen);
pcb->pcb_ldt = (caddr_t)new_ldt;
gdt_segs[GUSERLDT_SEL].ssd_base = (unsigned)new_ldt;
gdt_segs[GUSERLDT_SEL].ssd_limit = len - 1;
ssdtosd(&gdt_segs[GUSERLDT_SEL], &pcb->pcb_ldt_desc);
setsegment(&pcb->pcb_ldt_desc, new_ldt, len - 1, SDT_SYSLDT,
SEL_KPL, 0, 0);
if (p == curproc)
set_user_ldt(pcb);
#ifdef DEBUG

7
sys/arch/i386/i386/vm_machdep.c
View File

@ -1,4 +1,4 @@
/* $NetBSD: vm_machdep.c,v 1.50 1995/08/06 05:33:03 mycroft Exp $ */
/* $NetBSD: vm_machdep.c,v 1.51 1995/10/09 06:34:30 mycroft Exp $ */
/*-
* Copyright (c) 1995 Charles M. Hannum. All rights reserved.
@ -113,9 +113,8 @@ cpu_fork(p1, p2)
new_ldt = (union descriptor *)kmem_alloc(kernel_map, len);
bcopy(pcb->pcb_ldt, new_ldt, len);
pcb->pcb_ldt = (caddr_t)new_ldt;
gdt_segs[GUSERLDT_SEL].ssd_base = (unsigned)new_ldt;
gdt_segs[GUSERLDT_SEL].ssd_limit = len - 1;
ssdtosd(gdt_segs + GUSERLDT_SEL, &pcb->pcb_ldt_desc);
setsegment(&pcb->pcb_ldt_desc, new_ldt, len - 1, SDT_SYSLDT,
SEL_KPL, 0, 0);
}
#endif

29
sys/arch/i386/include/segments.h
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@ -1,4 +1,4 @@
/* $NetBSD: segments.h,v 1.14 1995/05/06 20:30:18 mycroft Exp $ */
/* $NetBSD: segments.h,v 1.15 1995/10/09 06:34:41 mycroft Exp $ */
/*-
* Copyright (c) 1995 Charles M. Hannum. All rights reserved.
@ -106,23 +106,6 @@ union descriptor {
struct gate_descriptor gd;
};
/*
* 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 ssd_base; /* segment base address */
unsigned ssd_limit; /* segment extent */
unsigned ssd_type:5; /* segment type */
unsigned ssd_dpl:2; /* segment descriptor priority level */
unsigned ssd_p:1; /* segment descriptor present */
unsigned ssd_xx:4; /* unused */
unsigned ssd_xx1:2; /* unused */
unsigned ssd_def32:1; /* default 32 vs 16 bit size */
unsigned ssd_gran:1; /* limit granularity (byte/page units)*/
};
/*
* region descriptors, used to load gdt/idt tables before segments yet exist.
*/
@ -139,9 +122,10 @@ struct region_descriptor {
extern int currentldt;
extern union descriptor gdt[], ldt[];
extern struct gate_descriptor idt[];
extern struct soft_segment_descriptor gdt_segs[], ldt_segs[];
void ssdtosd __P((struct soft_segment_descriptor *, struct segment_descriptor *));
void sdtossd __P((struct segment_descriptor *, struct soft_segment_descriptor *));
void setsegment __P((struct segment_descriptor *, void *, size_t, int, int,
int, int));
void setgate __P((struct gate_descriptor *, void *, int, int, int));
#endif /* _KERNEL */
#endif /* !LOCORE */
@ -236,6 +220,7 @@ void sdtossd __P((struct segment_descriptor *, struct soft_segment_descriptor *)
#define LSYS5SIGR_SEL 1 /* iBCS sigreturn gate */
#define LUCODE_SEL 2 /* User code descriptor */
#define LUDATA_SEL 3 /* User data descriptor */
#define NLDT 4
#define LBSDICALLS_SEL 16 /* BSDI system call gate */
#define NLDT 17
#endif /* _I386_SEGMENTS_H_ */

5
sys/arch/i386/isa/isa_machdep.c
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@ -1,4 +1,4 @@
/* $NetBSD: isa_machdep.c,v 1.7 1995/08/09 01:47:37 mycroft Exp $ */
/* $NetBSD: isa_machdep.c,v 1.8 1995/10/09 06:34:47 mycroft Exp $ */
/*-
* Copyright (c) 1993, 1994 Charles Hannum.
@ -54,7 +54,8 @@
#define IDTVEC(name) __CONCAT(X,name)
/* default interrupt vector table entries */
extern IDTVEC(wild), IDTVEC(intr)[], IDTVEC(fast)[];
typedef (*vector)();
extern vector IDTVEC(intr)[], IDTVEC(fast)[];
extern struct gate_descriptor idt[];
int isamatch __P((struct device *, void *, void *));