/
desctbls.c
1445 lines (1249 loc) · 37.8 KB
/
desctbls.c
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/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright (c) 2004, 2010, Oracle and/or its affiliates. All rights reserved.
*/
/*
* Copyright 2018 Joyent, Inc. All rights reserved.
*/
/*
* Copyright (c) 1992 Terrence R. Lambert.
* 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.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 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: @(#)machdep.c 7.4 (Berkeley) 6/3/91
*/
#include <sys/types.h>
#include <sys/sysmacros.h>
#include <sys/tss.h>
#include <sys/segments.h>
#include <sys/trap.h>
#include <sys/cpuvar.h>
#include <sys/bootconf.h>
#include <sys/x86_archext.h>
#include <sys/controlregs.h>
#include <sys/archsystm.h>
#include <sys/machsystm.h>
#include <sys/kobj.h>
#include <sys/cmn_err.h>
#include <sys/reboot.h>
#include <sys/kdi.h>
#include <sys/mach_mmu.h>
#include <sys/systm.h>
#include <sys/note.h>
#ifdef __xpv
#include <sys/hypervisor.h>
#include <vm/as.h>
#endif
#include <sys/promif.h>
#include <sys/bootinfo.h>
#include <vm/kboot_mmu.h>
#include <vm/hat_pte.h>
/*
* cpu0 and default tables and structures.
*/
user_desc_t *gdt0;
#if !defined(__xpv)
desctbr_t gdt0_default_r;
#endif
gate_desc_t *idt0; /* interrupt descriptor table */
#if defined(__i386)
desctbr_t idt0_default_r; /* describes idt0 in IDTR format */
#endif
tss_t *ktss0; /* kernel task state structure */
#if defined(__i386)
tss_t *dftss0; /* #DF double-fault exception */
#endif /* __i386 */
user_desc_t zero_udesc; /* base zero user desc native procs */
user_desc_t null_udesc; /* null user descriptor */
system_desc_t null_sdesc; /* null system descriptor */
#if defined(__amd64)
user_desc_t zero_u32desc; /* 32-bit compatibility procs */
#endif /* __amd64 */
#if defined(__amd64)
user_desc_t ucs_on;
user_desc_t ucs_off;
user_desc_t ucs32_on;
user_desc_t ucs32_off;
#endif /* __amd64 */
/*
* If the size of this is changed, you must update hat_pcp_setup() and the
* definitions in exception.s
*/
extern char dblfault_stack0[DEFAULTSTKSZ];
extern char nmi_stack0[DEFAULTSTKSZ];
extern char mce_stack0[DEFAULTSTKSZ];
extern void fast_null(void);
extern hrtime_t get_hrtime(void);
extern hrtime_t gethrvtime(void);
extern hrtime_t get_hrestime(void);
extern uint64_t getlgrp(void);
void (*(fasttable[]))(void) = {
fast_null, /* T_FNULL routine */
fast_null, /* T_FGETFP routine (initially null) */
fast_null, /* T_FSETFP routine (initially null) */
(void (*)())get_hrtime, /* T_GETHRTIME */
(void (*)())gethrvtime, /* T_GETHRVTIME */
(void (*)())get_hrestime, /* T_GETHRESTIME */
(void (*)())getlgrp /* T_GETLGRP */
};
/*
* Structure containing pre-computed descriptors to allow us to temporarily
* interpose on a standard handler.
*/
struct interposing_handler {
int ih_inum;
gate_desc_t ih_interp_desc;
gate_desc_t ih_default_desc;
};
/*
* The brand infrastructure interposes on two handlers, and we use one as a
* NULL signpost.
*/
static struct interposing_handler brand_tbl[2];
/*
* software prototypes for default local descriptor table
*/
/*
* Routines for loading segment descriptors in format the hardware
* can understand.
*/
/*
* In long mode we have the new L or long mode attribute bit
* for code segments. Only the conforming bit in type is used along
* with descriptor priority and present bits. Default operand size must
* be zero when in long mode. In 32-bit compatibility mode all fields
* are treated as in legacy mode. For data segments while in long mode
* only the present bit is loaded.
*/
void
set_usegd(user_desc_t *dp, uint_t lmode, void *base, size_t size,
uint_t type, uint_t dpl, uint_t gran, uint_t defopsz)
{
ASSERT(lmode == SDP_SHORT || lmode == SDP_LONG);
/* This should never be a "system" segment. */
ASSERT3U(type & SDT_S, !=, 0);
/*
* 64-bit long mode.
*/
if (lmode == SDP_LONG)
dp->usd_def32 = 0; /* 32-bit operands only */
else
/*
* 32-bit compatibility mode.
*/
dp->usd_def32 = defopsz; /* 0 = 16, 1 = 32-bit ops */
/*
* We should always set the "accessed" bit (SDT_A), otherwise the CPU
* will write to the GDT whenever we change segment registers around.
* With KPTI on, the GDT is read-only in the user page table, which
* causes crashes if we don't set this.
*/
ASSERT3U(type & SDT_A, !=, 0);
dp->usd_long = lmode; /* 64-bit mode */
dp->usd_type = type;
dp->usd_dpl = dpl;
dp->usd_p = 1;
dp->usd_gran = gran; /* 0 = bytes, 1 = pages */
dp->usd_lobase = (uintptr_t)base;
dp->usd_midbase = (uintptr_t)base >> 16;
dp->usd_hibase = (uintptr_t)base >> (16 + 8);
dp->usd_lolimit = size;
dp->usd_hilimit = (uintptr_t)size >> 16;
}
/*
* Install system segment descriptor for LDT and TSS segments.
*/
void
set_syssegd(system_desc_t *dp, void *base, size_t size, uint_t type,
uint_t dpl)
{
dp->ssd_lolimit = size;
dp->ssd_hilimit = (uintptr_t)size >> 16;
dp->ssd_lobase = (uintptr_t)base;
dp->ssd_midbase = (uintptr_t)base >> 16;
dp->ssd_hibase = (uintptr_t)base >> (16 + 8);
dp->ssd_hi64base = (uintptr_t)base >> (16 + 8 + 8);
dp->ssd_type = type;
dp->ssd_zero1 = 0; /* must be zero */
dp->ssd_zero2 = 0;
dp->ssd_dpl = dpl;
dp->ssd_p = 1;
dp->ssd_gran = 0; /* force byte units */
}
void *
get_ssd_base(system_desc_t *dp)
{
uintptr_t base;
base = (uintptr_t)dp->ssd_lobase |
(uintptr_t)dp->ssd_midbase << 16 |
(uintptr_t)dp->ssd_hibase << (16 + 8) |
(uintptr_t)dp->ssd_hi64base << (16 + 8 + 8);
return ((void *)base);
}
/*
* Install gate segment descriptor for interrupt, trap, call and task gates.
*
* For 64 bit native if we have KPTI enabled, we use the IST stack mechanism on
* all interrupts. We have different ISTs for each class of exceptions that are
* most likely to occur while handling an existing exception; while many of
* these are just going to panic, it's nice not to trample on the existing
* exception state for debugging purposes.
*
* Normal interrupts are all redirected unconditionally to the KPTI trampoline
* stack space. This unifies the trampoline handling between user and kernel
* space (and avoids the need to touch %gs).
*
* The KDI IDT *all* uses the DBG IST: consider single stepping tr_pftrap, when
* we do a read from KMDB that cause another #PF. Without its own IST, this
* would stomp on the kernel's mcpu_kpti_flt frame.
*/
uint_t
idt_vector_to_ist(uint_t vector)
{
#if defined(__xpv)
_NOTE(ARGUNUSED(vector));
return (IST_NONE);
#else
switch (vector) {
/* These should always use IST even without KPTI enabled. */
case T_DBLFLT:
return (IST_DF);
case T_NMIFLT:
return (IST_NMI);
case T_MCE:
return (IST_MCE);
case T_BPTFLT:
case T_SGLSTP:
if (kpti_enable == 1) {
return (IST_DBG);
}
return (IST_NONE);
case T_STKFLT:
case T_GPFLT:
case T_PGFLT:
if (kpti_enable == 1) {
return (IST_NESTABLE);
}
return (IST_NONE);
default:
if (kpti_enable == 1) {
return (IST_DEFAULT);
}
return (IST_NONE);
}
#endif
}
void
set_gatesegd(gate_desc_t *dp, void (*func)(void), selector_t sel,
uint_t type, uint_t dpl, uint_t ist)
{
dp->sgd_looffset = (uintptr_t)func;
dp->sgd_hioffset = (uintptr_t)func >> 16;
dp->sgd_hi64offset = (uintptr_t)func >> (16 + 16);
dp->sgd_selector = (uint16_t)sel;
dp->sgd_ist = ist;
dp->sgd_type = type;
dp->sgd_dpl = dpl;
dp->sgd_p = 1;
}
/*
* Updates a single user descriptor in the the GDT of the current cpu.
* Caller is responsible for preventing cpu migration.
*/
void
gdt_update_usegd(uint_t sidx, user_desc_t *udp)
{
#if defined(DEBUG)
/* This should never be a "system" segment, but it might be null. */
if (udp->usd_p != 0 || udp->usd_type != 0) {
ASSERT3U(udp->usd_type & SDT_S, !=, 0);
}
/*
* We should always set the "accessed" bit (SDT_A), otherwise the CPU
* will write to the GDT whenever we change segment registers around.
* With KPTI on, the GDT is read-only in the user page table, which
* causes crashes if we don't set this.
*/
if (udp->usd_p != 0 || udp->usd_type != 0) {
ASSERT3U(udp->usd_type & SDT_A, !=, 0);
}
#endif
#if defined(__xpv)
uint64_t dpa = CPU->cpu_m.mcpu_gdtpa + sizeof (*udp) * sidx;
if (HYPERVISOR_update_descriptor(pa_to_ma(dpa), *(uint64_t *)udp))
panic("gdt_update_usegd: HYPERVISOR_update_descriptor");
#else /* __xpv */
CPU->cpu_gdt[sidx] = *udp;
#endif /* __xpv */
}
/*
* Writes single descriptor pointed to by udp into a processes
* LDT entry pointed to by ldp.
*/
int
ldt_update_segd(user_desc_t *ldp, user_desc_t *udp)
{
#if defined(DEBUG)
/* This should never be a "system" segment, but it might be null. */
if (udp->usd_p != 0 || udp->usd_type != 0) {
ASSERT3U(udp->usd_type & SDT_S, !=, 0);
}
/*
* We should always set the "accessed" bit (SDT_A), otherwise the CPU
* will write to the LDT whenever we change segment registers around.
* With KPTI on, the LDT is read-only in the user page table, which
* causes crashes if we don't set this.
*/
if (udp->usd_p != 0 || udp->usd_type != 0) {
ASSERT3U(udp->usd_type & SDT_A, !=, 0);
}
#endif
#if defined(__xpv)
uint64_t dpa;
dpa = mmu_ptob(hat_getpfnum(kas.a_hat, (caddr_t)ldp)) |
((uintptr_t)ldp & PAGEOFFSET);
/*
* The hypervisor is a little more restrictive about what it
* supports in the LDT.
*/
if (HYPERVISOR_update_descriptor(pa_to_ma(dpa), *(uint64_t *)udp) != 0)
return (EINVAL);
#else /* __xpv */
*ldp = *udp;
#endif /* __xpv */
return (0);
}
#if defined(__xpv)
/*
* Converts hw format gate descriptor into pseudo-IDT format for the hypervisor.
* Returns true if a valid entry was written.
*/
int
xen_idt_to_trap_info(uint_t vec, gate_desc_t *sgd, void *ti_arg)
{
trap_info_t *ti = ti_arg; /* XXPV Aargh - segments.h comment */
/*
* skip holes in the IDT
*/
if (GATESEG_GETOFFSET(sgd) == 0)
return (0);
ASSERT(sgd->sgd_type == SDT_SYSIGT);
ti->vector = vec;
TI_SET_DPL(ti, sgd->sgd_dpl);
/*
* Is this an interrupt gate?
*/
if (sgd->sgd_type == SDT_SYSIGT) {
/* LINTED */
TI_SET_IF(ti, 1);
}
ti->cs = sgd->sgd_selector;
#if defined(__amd64)
ti->cs |= SEL_KPL; /* force into ring 3. see KCS_SEL */
#endif
ti->address = GATESEG_GETOFFSET(sgd);
return (1);
}
/*
* Convert a single hw format gate descriptor and write it into our virtual IDT.
*/
void
xen_idt_write(gate_desc_t *sgd, uint_t vec)
{
trap_info_t trapinfo[2];
bzero(trapinfo, sizeof (trapinfo));
if (xen_idt_to_trap_info(vec, sgd, &trapinfo[0]) == 0)
return;
if (xen_set_trap_table(trapinfo) != 0)
panic("xen_idt_write: xen_set_trap_table() failed");
}
#endif /* __xpv */
#if defined(__amd64)
/*
* Build kernel GDT.
*/
static void
init_gdt_common(user_desc_t *gdt)
{
int i;
/*
* 64-bit kernel code segment.
*/
set_usegd(&gdt[GDT_KCODE], SDP_LONG, NULL, 0, SDT_MEMERA, SEL_KPL,
SDP_PAGES, SDP_OP32);
/*
* 64-bit kernel data segment. The limit attribute is ignored in 64-bit
* mode, but we set it here to 0xFFFF so that we can use the SYSRET
* instruction to return from system calls back to 32-bit applications.
* SYSRET doesn't update the base, limit, or attributes of %ss or %ds
* descriptors. We therefore must ensure that the kernel uses something,
* though it will be ignored by hardware, that is compatible with 32-bit
* apps. For the same reason we must set the default op size of this
* descriptor to 32-bit operands.
*/
set_usegd(&gdt[GDT_KDATA], SDP_LONG, NULL, -1, SDT_MEMRWA,
SEL_KPL, SDP_PAGES, SDP_OP32);
gdt[GDT_KDATA].usd_def32 = 1;
/*
* 64-bit user code segment.
*/
set_usegd(&gdt[GDT_UCODE], SDP_LONG, NULL, 0, SDT_MEMERA, SEL_UPL,
SDP_PAGES, SDP_OP32);
/*
* 32-bit user code segment.
*/
set_usegd(&gdt[GDT_U32CODE], SDP_SHORT, NULL, -1, SDT_MEMERA,
SEL_UPL, SDP_PAGES, SDP_OP32);
/*
* See gdt_ucode32() and gdt_ucode_native().
*/
ucs_on = ucs_off = gdt[GDT_UCODE];
ucs_off.usd_p = 0; /* forces #np fault */
ucs32_on = ucs32_off = gdt[GDT_U32CODE];
ucs32_off.usd_p = 0; /* forces #np fault */
/*
* 32 and 64 bit data segments can actually share the same descriptor.
* In long mode only the present bit is checked but all other fields
* are loaded. But in compatibility mode all fields are interpreted
* as in legacy mode so they must be set correctly for a 32-bit data
* segment.
*/
set_usegd(&gdt[GDT_UDATA], SDP_SHORT, NULL, -1, SDT_MEMRWA, SEL_UPL,
SDP_PAGES, SDP_OP32);
#if !defined(__xpv)
/*
* The 64-bit kernel has no default LDT. By default, the LDT descriptor
* in the GDT is 0.
*/
/*
* Kernel TSS
*/
set_syssegd((system_desc_t *)&gdt[GDT_KTSS], ktss0,
sizeof (*ktss0) - 1, SDT_SYSTSS, SEL_KPL);
#endif /* !__xpv */
/*
* Initialize fs and gs descriptors for 32 bit processes.
* Only attributes and limits are initialized, the effective
* base address is programmed via fsbase/gsbase.
*/
set_usegd(&gdt[GDT_LWPFS], SDP_SHORT, NULL, -1, SDT_MEMRWA,
SEL_UPL, SDP_PAGES, SDP_OP32);
set_usegd(&gdt[GDT_LWPGS], SDP_SHORT, NULL, -1, SDT_MEMRWA,
SEL_UPL, SDP_PAGES, SDP_OP32);
/*
* Initialize the descriptors set aside for brand usage.
* Only attributes and limits are initialized.
*/
for (i = GDT_BRANDMIN; i <= GDT_BRANDMAX; i++)
set_usegd(&gdt0[i], SDP_SHORT, NULL, -1, SDT_MEMRWA,
SEL_UPL, SDP_PAGES, SDP_OP32);
/*
* Initialize convenient zero base user descriptors for clearing
* lwp private %fs and %gs descriptors in GDT. See setregs() for
* an example.
*/
set_usegd(&zero_udesc, SDP_LONG, 0, 0, SDT_MEMRWA, SEL_UPL,
SDP_BYTES, SDP_OP32);
set_usegd(&zero_u32desc, SDP_SHORT, 0, -1, SDT_MEMRWA, SEL_UPL,
SDP_PAGES, SDP_OP32);
}
#if defined(__xpv)
static user_desc_t *
init_gdt(void)
{
uint64_t gdtpa;
ulong_t ma[1]; /* XXPV should be a memory_t */
ulong_t addr;
#if !defined(__lint)
/*
* Our gdt is never larger than a single page.
*/
ASSERT((sizeof (*gdt0) * NGDT) <= PAGESIZE);
#endif
gdt0 = (user_desc_t *)BOP_ALLOC(bootops, (caddr_t)GDT_VA,
PAGESIZE, PAGESIZE);
bzero(gdt0, PAGESIZE);
init_gdt_common(gdt0);
/*
* XXX Since we never invoke kmdb until after the kernel takes
* over the descriptor tables why not have it use the kernel's
* selectors?
*/
if (boothowto & RB_DEBUG) {
set_usegd(&gdt0[GDT_B32DATA], SDP_LONG, NULL, -1, SDT_MEMRWA,
SEL_KPL, SDP_PAGES, SDP_OP32);
set_usegd(&gdt0[GDT_B64CODE], SDP_LONG, NULL, -1, SDT_MEMERA,
SEL_KPL, SDP_PAGES, SDP_OP32);
}
/*
* Clear write permission for page containing the gdt and install it.
*/
gdtpa = pfn_to_pa(va_to_pfn(gdt0));
ma[0] = (ulong_t)(pa_to_ma(gdtpa) >> PAGESHIFT);
kbm_read_only((uintptr_t)gdt0, gdtpa);
xen_set_gdt(ma, NGDT);
/*
* Reload the segment registers to use the new GDT.
* On 64-bit, fixup KCS_SEL to be in ring 3.
* See KCS_SEL in segments.h.
*/
load_segment_registers((KCS_SEL | SEL_KPL), KFS_SEL, KGS_SEL, KDS_SEL);
/*
* setup %gs for kernel
*/
xen_set_segment_base(SEGBASE_GS_KERNEL, (ulong_t)&cpus[0]);
/*
* XX64 We should never dereference off "other gsbase" or
* "fsbase". So, we should arrange to point FSBASE and
* KGSBASE somewhere truly awful e.g. point it at the last
* valid address below the hole so that any attempts to index
* off them cause an exception.
*
* For now, point it at 8G -- at least it should be unmapped
* until some 64-bit processes run.
*/
addr = 0x200000000ul;
xen_set_segment_base(SEGBASE_FS, addr);
xen_set_segment_base(SEGBASE_GS_USER, addr);
xen_set_segment_base(SEGBASE_GS_USER_SEL, 0);
return (gdt0);
}
#else /* __xpv */
static user_desc_t *
init_gdt(void)
{
desctbr_t r_bgdt, r_gdt;
user_desc_t *bgdt;
#if !defined(__lint)
/*
* Our gdt is never larger than a single page.
*/
ASSERT((sizeof (*gdt0) * NGDT) <= PAGESIZE);
#endif
gdt0 = (user_desc_t *)BOP_ALLOC(bootops, (caddr_t)GDT_VA,
PAGESIZE, PAGESIZE);
bzero(gdt0, PAGESIZE);
init_gdt_common(gdt0);
/*
* Copy in from boot's gdt to our gdt.
* Entry 0 is the null descriptor by definition.
*/
rd_gdtr(&r_bgdt);
bgdt = (user_desc_t *)r_bgdt.dtr_base;
if (bgdt == NULL)
panic("null boot gdt");
gdt0[GDT_B32DATA] = bgdt[GDT_B32DATA];
gdt0[GDT_B32CODE] = bgdt[GDT_B32CODE];
gdt0[GDT_B16CODE] = bgdt[GDT_B16CODE];
gdt0[GDT_B16DATA] = bgdt[GDT_B16DATA];
gdt0[GDT_B64CODE] = bgdt[GDT_B64CODE];
/*
* Install our new GDT
*/
r_gdt.dtr_limit = (sizeof (*gdt0) * NGDT) - 1;
r_gdt.dtr_base = (uintptr_t)gdt0;
wr_gdtr(&r_gdt);
/*
* Reload the segment registers to use the new GDT
*/
load_segment_registers(KCS_SEL, KFS_SEL, KGS_SEL, KDS_SEL);
/*
* setup %gs for kernel
*/
wrmsr(MSR_AMD_GSBASE, (uint64_t)&cpus[0]);
/*
* XX64 We should never dereference off "other gsbase" or
* "fsbase". So, we should arrange to point FSBASE and
* KGSBASE somewhere truly awful e.g. point it at the last
* valid address below the hole so that any attempts to index
* off them cause an exception.
*
* For now, point it at 8G -- at least it should be unmapped
* until some 64-bit processes run.
*/
wrmsr(MSR_AMD_FSBASE, 0x200000000ul);
wrmsr(MSR_AMD_KGSBASE, 0x200000000ul);
return (gdt0);
}
#endif /* __xpv */
#elif defined(__i386)
static void
init_gdt_common(user_desc_t *gdt)
{
int i;
/*
* Text and data for both kernel and user span entire 32 bit
* address space.
*/
/*
* kernel code segment.
*/
set_usegd(&gdt[GDT_KCODE], NULL, -1, SDT_MEMERA, SEL_KPL, SDP_PAGES,
SDP_OP32);
/*
* kernel data segment.
*/
set_usegd(&gdt[GDT_KDATA], NULL, -1, SDT_MEMRWA, SEL_KPL, SDP_PAGES,
SDP_OP32);
/*
* user code segment.
*/
set_usegd(&gdt[GDT_UCODE], NULL, -1, SDT_MEMERA, SEL_UPL, SDP_PAGES,
SDP_OP32);
/*
* user data segment.
*/
set_usegd(&gdt[GDT_UDATA], NULL, -1, SDT_MEMRWA, SEL_UPL, SDP_PAGES,
SDP_OP32);
#if !defined(__xpv)
/*
* TSS for T_DBLFLT (double fault) handler
*/
set_syssegd((system_desc_t *)&gdt[GDT_DBFLT], dftss0,
sizeof (*dftss0) - 1, SDT_SYSTSS, SEL_KPL);
/*
* TSS for kernel
*/
set_syssegd((system_desc_t *)&gdt[GDT_KTSS], ktss0,
sizeof (*ktss0) - 1, SDT_SYSTSS, SEL_KPL);
#endif /* !__xpv */
/*
* %gs selector for kernel
*/
set_usegd(&gdt[GDT_GS], &cpus[0], sizeof (struct cpu) -1, SDT_MEMRWA,
SEL_KPL, SDP_BYTES, SDP_OP32);
/*
* Initialize lwp private descriptors.
* Only attributes and limits are initialized, the effective
* base address is programmed via fsbase/gsbase.
*/
set_usegd(&gdt[GDT_LWPFS], NULL, (size_t)-1, SDT_MEMRWA, SEL_UPL,
SDP_PAGES, SDP_OP32);
set_usegd(&gdt[GDT_LWPGS], NULL, (size_t)-1, SDT_MEMRWA, SEL_UPL,
SDP_PAGES, SDP_OP32);
/*
* Initialize the descriptors set aside for brand usage.
* Only attributes and limits are initialized.
*/
for (i = GDT_BRANDMIN; i <= GDT_BRANDMAX; i++)
set_usegd(&gdt0[i], NULL, (size_t)-1, SDT_MEMRWA, SEL_UPL,
SDP_PAGES, SDP_OP32);
/*
* Initialize convenient zero base user descriptor for clearing
* lwp private %fs and %gs descriptors in GDT. See setregs() for
* an example.
*/
set_usegd(&zero_udesc, NULL, -1, SDT_MEMRWA, SEL_UPL,
SDP_BYTES, SDP_OP32);
}
#if defined(__xpv)
static user_desc_t *
init_gdt(void)
{
uint64_t gdtpa;
ulong_t ma[1]; /* XXPV should be a memory_t */
#if !defined(__lint)
/*
* Our gdt is never larger than a single page.
*/
ASSERT((sizeof (*gdt0) * NGDT) <= PAGESIZE);
#endif
gdt0 = (user_desc_t *)BOP_ALLOC(bootops, (caddr_t)GDT_VA,
PAGESIZE, PAGESIZE);
bzero(gdt0, PAGESIZE);
init_gdt_common(gdt0);
gdtpa = pfn_to_pa(va_to_pfn(gdt0));
/*
* XXX Since we never invoke kmdb until after the kernel takes
* over the descriptor tables why not have it use the kernel's
* selectors?
*/
if (boothowto & RB_DEBUG) {
set_usegd(&gdt0[GDT_B32DATA], NULL, -1, SDT_MEMRWA, SEL_KPL,
SDP_PAGES, SDP_OP32);
set_usegd(&gdt0[GDT_B32CODE], NULL, -1, SDT_MEMERA, SEL_KPL,
SDP_PAGES, SDP_OP32);
}
/*
* Clear write permission for page containing the gdt and install it.
*/
ma[0] = (ulong_t)(pa_to_ma(gdtpa) >> PAGESHIFT);
kbm_read_only((uintptr_t)gdt0, gdtpa);
xen_set_gdt(ma, NGDT);
/*
* Reload the segment registers to use the new GDT
*/
load_segment_registers(
KCS_SEL, KDS_SEL, KDS_SEL, KFS_SEL, KGS_SEL, KDS_SEL);
return (gdt0);
}
#else /* __xpv */
static user_desc_t *
init_gdt(void)
{
desctbr_t r_bgdt, r_gdt;
user_desc_t *bgdt;
#if !defined(__lint)
/*
* Our gdt is never larger than a single page.
*/
ASSERT((sizeof (*gdt0) * NGDT) <= PAGESIZE);
#endif
/*
* XXX this allocation belongs in our caller, not here.
*/
gdt0 = (user_desc_t *)BOP_ALLOC(bootops, (caddr_t)GDT_VA,
PAGESIZE, PAGESIZE);
bzero(gdt0, PAGESIZE);
init_gdt_common(gdt0);
/*
* Copy in from boot's gdt to our gdt entries.
* Entry 0 is null descriptor by definition.
*/
rd_gdtr(&r_bgdt);
bgdt = (user_desc_t *)r_bgdt.dtr_base;
if (bgdt == NULL)
panic("null boot gdt");
gdt0[GDT_B32DATA] = bgdt[GDT_B32DATA];
gdt0[GDT_B32CODE] = bgdt[GDT_B32CODE];
gdt0[GDT_B16CODE] = bgdt[GDT_B16CODE];
gdt0[GDT_B16DATA] = bgdt[GDT_B16DATA];
/*
* Install our new GDT
*/
r_gdt.dtr_limit = (sizeof (*gdt0) * NGDT) - 1;
r_gdt.dtr_base = (uintptr_t)gdt0;
wr_gdtr(&r_gdt);
/*
* Reload the segment registers to use the new GDT
*/
load_segment_registers(
KCS_SEL, KDS_SEL, KDS_SEL, KFS_SEL, KGS_SEL, KDS_SEL);
return (gdt0);
}
#endif /* __xpv */
#endif /* __i386 */
/*
* Build kernel IDT.
*
* Note that for amd64 we pretty much require every gate to be an interrupt
* gate which blocks interrupts atomically on entry; that's because of our
* dependency on using 'swapgs' every time we come into the kernel to find
* the cpu structure. If we get interrupted just before doing that, %cs could
* be in kernel mode (so that the trap prolog doesn't do a swapgs), but
* %gsbase is really still pointing at something in userland. Bad things will
* ensue. We also use interrupt gates for i386 as well even though this is not
* required for some traps.
*
* Perhaps they should have invented a trap gate that does an atomic swapgs?
*/
static void
init_idt_common(gate_desc_t *idt)
{
set_gatesegd(&idt[T_ZERODIV],
(kpti_enable == 1) ? &tr_div0trap : &div0trap,
KCS_SEL, SDT_SYSIGT, TRP_KPL, idt_vector_to_ist(T_ZERODIV));
set_gatesegd(&idt[T_SGLSTP],
(kpti_enable == 1) ? &tr_dbgtrap : &dbgtrap,
KCS_SEL, SDT_SYSIGT, TRP_KPL, idt_vector_to_ist(T_SGLSTP));
set_gatesegd(&idt[T_NMIFLT],
(kpti_enable == 1) ? &tr_nmiint : &nmiint,
KCS_SEL, SDT_SYSIGT, TRP_KPL, idt_vector_to_ist(T_NMIFLT));
set_gatesegd(&idt[T_BPTFLT],
(kpti_enable == 1) ? &tr_brktrap : &brktrap,
KCS_SEL, SDT_SYSIGT, TRP_UPL, idt_vector_to_ist(T_BPTFLT));
set_gatesegd(&idt[T_OVFLW],
(kpti_enable == 1) ? &tr_ovflotrap : &ovflotrap,
KCS_SEL, SDT_SYSIGT, TRP_UPL, idt_vector_to_ist(T_OVFLW));
set_gatesegd(&idt[T_BOUNDFLT],
(kpti_enable == 1) ? &tr_boundstrap : &boundstrap,
KCS_SEL, SDT_SYSIGT, TRP_KPL, idt_vector_to_ist(T_BOUNDFLT));
set_gatesegd(&idt[T_ILLINST],
(kpti_enable == 1) ? &tr_invoptrap : &invoptrap,
KCS_SEL, SDT_SYSIGT, TRP_KPL, idt_vector_to_ist(T_ILLINST));
set_gatesegd(&idt[T_NOEXTFLT],
(kpti_enable == 1) ? &tr_ndptrap : &ndptrap,
KCS_SEL, SDT_SYSIGT, TRP_KPL, idt_vector_to_ist(T_NOEXTFLT));
/*
* double fault handler.
*
* Note that on the hypervisor a guest does not receive #df faults.
* Instead a failsafe event is injected into the guest if its selectors
* and/or stack is in a broken state. See xen_failsafe_callback.
*/
#if !defined(__xpv)
set_gatesegd(&idt[T_DBLFLT],
(kpti_enable == 1) ? &tr_syserrtrap : &syserrtrap,
KCS_SEL, SDT_SYSIGT, TRP_KPL, idt_vector_to_ist(T_DBLFLT));
#endif /* !__xpv */
/*
* T_EXTOVRFLT coprocessor-segment-overrun not supported.
*/
set_gatesegd(&idt[T_TSSFLT],
(kpti_enable == 1) ? &tr_invtsstrap : &invtsstrap,
KCS_SEL, SDT_SYSIGT, TRP_KPL, idt_vector_to_ist(T_TSSFLT));
set_gatesegd(&idt[T_SEGFLT],
(kpti_enable == 1) ? &tr_segnptrap : &segnptrap,
KCS_SEL, SDT_SYSIGT, TRP_KPL, idt_vector_to_ist(T_SEGFLT));
set_gatesegd(&idt[T_STKFLT],
(kpti_enable == 1) ? &tr_stktrap : &stktrap,
KCS_SEL, SDT_SYSIGT, TRP_KPL, idt_vector_to_ist(T_STKFLT));
set_gatesegd(&idt[T_GPFLT],
(kpti_enable == 1) ? &tr_gptrap : &gptrap,
KCS_SEL, SDT_SYSIGT, TRP_KPL, idt_vector_to_ist(T_GPFLT));
set_gatesegd(&idt[T_PGFLT],
(kpti_enable == 1) ? &tr_pftrap : &pftrap,
KCS_SEL, SDT_SYSIGT, TRP_KPL, idt_vector_to_ist(T_PGFLT));
set_gatesegd(&idt[T_EXTERRFLT],
(kpti_enable == 1) ? &tr_ndperr : &ndperr,
KCS_SEL, SDT_SYSIGT, TRP_KPL, idt_vector_to_ist(T_EXTERRFLT));
set_gatesegd(&idt[T_ALIGNMENT],
(kpti_enable == 1) ? &tr_achktrap : &achktrap,
KCS_SEL, SDT_SYSIGT, TRP_KPL, idt_vector_to_ist(T_ALIGNMENT));
set_gatesegd(&idt[T_MCE],
(kpti_enable == 1) ? &tr_mcetrap : &mcetrap,
KCS_SEL, SDT_SYSIGT, TRP_KPL, idt_vector_to_ist(T_MCE));
set_gatesegd(&idt[T_SIMDFPE],
(kpti_enable == 1) ? &tr_xmtrap : &xmtrap,
KCS_SEL, SDT_SYSIGT, TRP_KPL, idt_vector_to_ist(T_SIMDFPE));
/*
* install fast trap handler at 210.
*/
set_gatesegd(&idt[T_FASTTRAP],
(kpti_enable == 1) ? &tr_fasttrap : &fasttrap,
KCS_SEL, SDT_SYSIGT, TRP_UPL, idt_vector_to_ist(T_FASTTRAP));
/*
* System call handler.
*/
set_gatesegd(&idt[T_SYSCALLINT],
(kpti_enable == 1) ? &tr_sys_syscall_int : &sys_syscall_int,
KCS_SEL, SDT_SYSIGT, TRP_UPL, idt_vector_to_ist(T_SYSCALLINT));
/*