osfmk/i386/mp_desc.c

   1 /*
   2  * Copyright (c) 2000-2019 Apple Inc. All rights reserved.
   3  *
   4  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. The rights granted to you under the License
  10  * may not be used to create, or enable the creation or redistribution of,
  11  * unlawful or unlicensed copies of an Apple operating system, or to
  12  * circumvent, violate, or enable the circumvention or violation of, any
  13  * terms of an Apple operating system software license agreement.
  14  *
  15  * Please obtain a copy of the License at
  16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
  17  *
  18  * The Original Code and all software distributed under the License are
  19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  23  * Please see the License for the specific language governing rights and
  24  * limitations under the License.
  25  *
  26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  27  */
  28 /*
  29  * @OSF_COPYRIGHT@
  30  */
  31 /*
  32  * Mach Operating System
  33  * Copyright (c) 1991,1990 Carnegie Mellon University
  34  * All Rights Reserved.
  35  *
  36  * Permission to use, copy, modify and distribute this software and its
  37  * documentation is hereby granted, provided that both the copyright
  38  * notice and this permission notice appear in all copies of the
  39  * software, derivative works or modified versions, and any portions
  40  * thereof, and that both notices appear in supporting documentation.
  41  *
  42  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
  43  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
  44  * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
  45  *
  46  * Carnegie Mellon requests users of this software to return to
  47  *
  48  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
  49  *  School of Computer Science
  50  *  Carnegie Mellon University
  51  *  Pittsburgh PA 15213-3890
  52  *
  53  * any improvements or extensions that they make and grant Carnegie Mellon
  54  * the rights to redistribute these changes.
  55  */
  56
  57 /*
  58  */
  59
  60 #include <kern/cpu_number.h>
  61 #include <kern/cpu_data.h>
  62 #include <kern/percpu.h>
  63 #include <mach/mach_types.h>
  64 #include <mach/machine.h>
  65 #include <mach/vm_map.h>
  66 #include <mach/machine/vm_param.h>
  67 #include <vm/vm_kern.h>
  68 #include <vm/vm_map.h>
  69
  70 #include <i386/bit_routines.h>
  71 #include <i386/mp_desc.h>
  72 #include <i386/misc_protos.h>
  73 #include <i386/mp.h>
  74 #include <i386/pmap.h>
  75 #include <i386/postcode.h>
  76 #include <i386/pmap_internal.h>
  77 #if CONFIG_MCA
  78 #include <i386/machine_check.h>
  79 #endif
  80
  81 #include <kern/misc_protos.h>
  82
  83 #if MONOTONIC
  84 #include <kern/monotonic.h>
  85 #endif /* MONOTONIC */
  86 #include <san/kasan.h>
  87
  88 #define K_INTR_GATE (ACC_P|ACC_PL_K|ACC_INTR_GATE)
  89 #define U_INTR_GATE (ACC_P|ACC_PL_U|ACC_INTR_GATE)
  90
  91 // Declare macros that will declare the externs
  92 #define TRAP(n, name)           extern void *name ;
  93 #define TRAP_ERR(n, name)       extern void *name ;
  94 #define TRAP_SPC(n, name)       extern void *name ;
  95 #define TRAP_IST1(n, name)      extern void *name ;
  96 #define TRAP_IST2(n, name)      extern void *name ;
  97 #define INTERRUPT(n)            extern void *_intr_ ## n ;
  98 #define USER_TRAP(n, name)      extern void *name ;
  99 #define USER_TRAP_SPC(n, name)  extern void *name ;
 100
 101 // Include the table to declare the externs
 102 #include "../x86_64/idt_table.h"
 103
 104 // Undef the macros, then redefine them so we can declare the table
 105 #undef TRAP
 106 #undef TRAP_ERR
 107 #undef TRAP_SPC
 108 #undef TRAP_IST1
 109 #undef TRAP_IST2
 110 #undef INTERRUPT
 111 #undef USER_TRAP
 112 #undef USER_TRAP_SPC
 113
 114 #define TRAP(n, name)                   \
 115         [n] = {                         \
 116                 (uintptr_t)&name,       \
 117                 KERNEL64_CS,            \
 118                 0,                      \
 119                 K_INTR_GATE,            \
 120                 0                       \
 121         },
 122
 123 #define TRAP_ERR TRAP
 124 #define TRAP_SPC TRAP
 125
 126 #define TRAP_IST1(n, name) \
 127         [n] = {                         \
 128                 (uintptr_t)&name,       \
 129                 KERNEL64_CS,            \
 130                 1,                      \
 131                 K_INTR_GATE,            \
 132                 0                       \
 133         },
 134
 135 #define TRAP_IST2(n, name) \
 136         [n] = {                         \
 137                 (uintptr_t)&name,       \
 138                 KERNEL64_CS,            \
 139                 2,                      \
 140                 K_INTR_GATE,            \
 141                 0                       \
 142         },
 143
 144 #define INTERRUPT(n) \
 145         [n] = {                         \
 146                 (uintptr_t)&_intr_ ## n,\
 147                 KERNEL64_CS,            \
 148                 0,                      \
 149                 K_INTR_GATE,            \
 150                 0                       \
 151         },
 152
 153 #define USER_TRAP(n, name) \
 154         [n] = {                         \
 155                 (uintptr_t)&name,       \
 156                 KERNEL64_CS,            \
 157                 0,                      \
 158                 U_INTR_GATE,            \
 159                 0                       \
 160         },
 161
 162 #define USER_TRAP_SPC USER_TRAP
 163
 164 // Declare the table using the macros we just set up
 165 struct fake_descriptor64 master_idt64[IDTSZ]
 166 __attribute__ ((section("__HIB,__desc")))
 167 __attribute__ ((aligned(PAGE_SIZE))) = {
 168 #include "../x86_64/idt_table.h"
 169 };
 170
 171 /*
 172  * First cpu`s interrupt stack.
 173  */
 174 extern uint32_t         low_intstack[];         /* bottom */
 175 extern uint32_t         low_eintstack[];        /* top */
 176
 177 /*
 178  * Per-cpu data area pointers.
 179  */
 180 cpu_data_t cpshadows[MAX_CPUS] __attribute__((aligned(64))) __attribute__((section("__HIB, __desc")));
 181 cpu_data_t scdatas[MAX_CPUS] __attribute__((aligned(64))) = {
 182         [0].cpu_this = &scdatas[0],
 183         [0].cpu_nanotime = &pal_rtc_nanotime_info,
 184         [0].cpu_int_stack_top = (vm_offset_t) low_eintstack,
 185         [0].cd_shadow = &cpshadows[0]
 186 };
 187 cpu_data_t *cpu_data_master = &scdatas[0];
 188
 189 cpu_data_t      *cpu_data_ptr[MAX_CPUS] = {[0] = &scdatas[0] };
 190
 191 SECURITY_READ_ONLY_LATE(struct percpu_base) percpu_base;
 192
 193 decl_simple_lock_data(, ncpus_lock);     /* protects real_ncpus */
 194 unsigned int    real_ncpus = 1;
 195 unsigned int    max_ncpus = MAX_CPUS;
 196 unsigned int    max_cpus_from_firmware = 0;
 197
 198 extern void hi64_sysenter(void);
 199 extern void hi64_syscall(void);
 200
 201 typedef struct {
 202         struct real_descriptor pcldts[LDTSZ];
 203 } cldt_t;
 204
 205 cpu_desc_table64_t scdtables[MAX_CPUS] __attribute__((aligned(64))) __attribute__((section("__HIB, __desc")));
 206 cpu_fault_stack_t scfstks[MAX_CPUS] __attribute__((aligned(64))) __attribute__((section("__HIB, __desc")));
 207
 208 cldt_t *dyn_ldts;
 209
 210 /*
 211  * Multiprocessor i386/i486 systems use a separate copy of the
 212  * GDT, IDT, LDT, and kernel TSS per processor.  The first three
 213  * are separate to avoid lock contention: the i386 uses locked
 214  * memory cycles to access the descriptor tables.  The TSS is
 215  * separate since each processor needs its own kernel stack,
 216  * and since using a TSS marks it busy.
 217  */
 218
 219 /*
 220  * Allocate and initialize the per-processor descriptor tables.
 221  */
 222
 223 /*
 224  * This is the expanded, 64-bit variant of the kernel LDT descriptor.
 225  * When switching to 64-bit mode this replaces KERNEL_LDT entry
 226  * and the following empty slot. This enables the LDT to be referenced
 227  * in the uber-space remapping window on the kernel.
 228  */
 229 struct fake_descriptor64 kernel_ldt_desc64 = {
 230         .offset64 = 0,
 231         .lim_or_seg = LDTSZ_MIN * sizeof(struct fake_descriptor) - 1,
 232         .size_or_IST = 0,
 233         .access = ACC_P | ACC_PL_K | ACC_LDT,
 234         .reserved = 0
 235 };
 236
 237 /*
 238  * This is the expanded, 64-bit variant of the kernel TSS descriptor.
 239  * It is follows pattern of the KERNEL_LDT.
 240  */
 241 struct fake_descriptor64 kernel_tss_desc64 = {
 242         .offset64 = 0,
 243         .lim_or_seg = sizeof(struct x86_64_tss) - 1,
 244         .size_or_IST = 0,
 245         .access = ACC_P | ACC_PL_K | ACC_TSS,
 246         .reserved = 0
 247 };
 248
 249 /*
 250  * Convert a descriptor from fake to real format.
 251  *
 252  * Fake descriptor format:
 253  *      bytes 0..3              base 31..0
 254  *      bytes 4..5              limit 15..0
 255  *      byte  6                 access byte 2 | limit 19..16
 256  *      byte  7                 access byte 1
 257  *
 258  * Real descriptor format:
 259  *      bytes 0..1              limit 15..0
 260  *      bytes 2..3              base 15..0
 261  *      byte  4                 base 23..16
 262  *      byte  5                 access byte 1
 263  *      byte  6                 access byte 2 | limit 19..16
 264  *      byte  7                 base 31..24
 265  *
 266  * Fake gate format:
 267  *      bytes 0..3              offset
 268  *      bytes 4..5              selector
 269  *      byte  6                 word count << 4 (to match fake descriptor)
 270  *      byte  7                 access byte 1
 271  *
 272  * Real gate format:
 273  *      bytes 0..1              offset 15..0
 274  *      bytes 2..3              selector
 275  *      byte  4                 word count
 276  *      byte  5                 access byte 1
 277  *      bytes 6..7              offset 31..16
 278  */
 279 void
 280 fix_desc(void *d, int num_desc)
 281 {
 282         uint8_t *desc = (uint8_t*) d;
 283
 284         do {
 285                 if ((desc[7] & 0x14) == 0x04) { /* gate */
 286                         uint32_t offset;
 287                         uint16_t selector;
 288                         uint8_t wordcount;
 289                         uint8_t acc;
 290
 291                         offset = *((uint32_t*)(desc));
 292                         selector = *((uint32_t*)(desc + 4));
 293                         wordcount = desc[6] >> 4;
 294                         acc = desc[7];
 295
 296                         *((uint16_t*)desc) = offset & 0xFFFF;
 297                         *((uint16_t*)(desc + 2)) = selector;
 298                         desc[4] = wordcount;
 299                         desc[5] = acc;
 300                         *((uint16_t*)(desc + 6)) = offset >> 16;
 301                 } else { /* descriptor */
 302                         uint32_t base;
 303                         uint16_t limit;
 304                         uint8_t acc1, acc2;
 305
 306                         base = *((uint32_t*)(desc));
 307                         limit = *((uint16_t*)(desc + 4));
 308                         acc2 = desc[6];
 309                         acc1 = desc[7];
 310
 311                         *((uint16_t*)(desc)) = limit;
 312                         *((uint16_t*)(desc + 2)) = base & 0xFFFF;
 313                         desc[4] = (base >> 16) & 0xFF;
 314                         desc[5] = acc1;
 315                         desc[6] = acc2;
 316                         desc[7] = base >> 24;
 317                 }
 318                 desc += 8;
 319         } while (--num_desc);
 320 }
 321
 322 void
 323 fix_desc64(void *descp, int count)
 324 {
 325         struct fake_descriptor64        *fakep;
 326         union {
 327                 struct real_gate64              gate;
 328                 struct real_descriptor64        desc;
 329         }                               real;
 330         int                             i;
 331
 332         fakep = (struct fake_descriptor64 *) descp;
 333
 334         for (i = 0; i < count; i++, fakep++) {
 335                 /*
 336                  * Construct the real decriptor locally.
 337                  */
 338
 339                 bzero((void *) &real, sizeof(real));
 340
 341                 switch (fakep->access & ACC_TYPE) {
 342                 case 0:
 343                         break;
 344                 case ACC_CALL_GATE:
 345                 case ACC_INTR_GATE:
 346                 case ACC_TRAP_GATE:
 347                         real.gate.offset_low16 = (uint16_t)(fakep->offset64 & 0xFFFF);
 348                         real.gate.selector16 = fakep->lim_or_seg & 0xFFFF;
 349                         real.gate.IST = fakep->size_or_IST & 0x7;
 350                         real.gate.access8 = fakep->access;
 351                         real.gate.offset_high16 = (uint16_t)((fakep->offset64 >> 16) & 0xFFFF);
 352                         real.gate.offset_top32 = (uint32_t)(fakep->offset64 >> 32);
 353                         break;
 354                 default:        /* Otherwise */
 355                         real.desc.limit_low16 = fakep->lim_or_seg & 0xFFFF;
 356                         real.desc.base_low16 = (uint16_t)(fakep->offset64 & 0xFFFF);
 357                         real.desc.base_med8 = (uint8_t)((fakep->offset64 >> 16) & 0xFF);
 358                         real.desc.access8 = fakep->access;
 359                         real.desc.limit_high4 = (fakep->lim_or_seg >> 16) & 0xFF;
 360                         real.desc.granularity4 = fakep->size_or_IST;
 361                         real.desc.base_high8 = (uint8_t)((fakep->offset64 >> 24) & 0xFF);
 362                         real.desc.base_top32 = (uint32_t)(fakep->offset64 >> 32);
 363                 }
 364
 365                 /*
 366                  * Now copy back over the fake structure.
 367                  */
 368                 bcopy((void *) &real, (void *) fakep, sizeof(real));
 369         }
 370 }
 371
 372 extern unsigned mldtsz;
 373 void
 374 cpu_desc_init(cpu_data_t *cdp)
 375 {
 376         cpu_desc_index_t        *cdi = &cdp->cpu_desc_index;
 377
 378         if (cdp == cpu_data_master) {
 379                 /*
 380                  * Populate the double-mapped 'u' and base 'b' fields in the
 381                  * KTSS with I/G/LDT and sysenter stack data.
 382                  */
 383                 cdi->cdi_ktssu = (void *)DBLMAP(&master_ktss64);
 384                 cdi->cdi_ktssb = (void *)&master_ktss64;
 385                 cdi->cdi_sstku = (vm_offset_t) DBLMAP(&master_sstk.top);
 386                 cdi->cdi_sstkb = (vm_offset_t) &master_sstk.top;
 387
 388                 cdi->cdi_gdtu.ptr = (void *)DBLMAP((uintptr_t) &master_gdt);
 389                 cdi->cdi_gdtb.ptr = (void *)&master_gdt;
 390                 cdi->cdi_idtu.ptr  = (void *)DBLMAP((uintptr_t) &master_idt64);
 391                 cdi->cdi_idtb.ptr  = (void *)((uintptr_t) &master_idt64);
 392                 cdi->cdi_ldtu  = (struct real_descriptor *)DBLMAP((uintptr_t)&master_ldt[0]);
 393                 cdi->cdi_ldtb  = &master_ldt[0];
 394
 395                 /* Replace the expanded LDTs and TSS slots in the GDT */
 396                 kernel_ldt_desc64.offset64 = (uintptr_t) cdi->cdi_ldtu;
 397                 *(struct fake_descriptor64 *) &master_gdt[sel_idx(KERNEL_LDT)] =
 398                     kernel_ldt_desc64;
 399                 *(struct fake_descriptor64 *) &master_gdt[sel_idx(USER_LDT)] =
 400                     kernel_ldt_desc64;
 401                 kernel_tss_desc64.offset64 = (uintptr_t) DBLMAP(&master_ktss64);
 402                 *(struct fake_descriptor64 *) &master_gdt[sel_idx(KERNEL_TSS)] =
 403                     kernel_tss_desc64;
 404
 405                 /* Fix up the expanded descriptors for 64-bit. */
 406                 fix_desc64((void *) &master_idt64, IDTSZ);
 407                 fix_desc64((void *) &master_gdt[sel_idx(KERNEL_LDT)], 1);
 408                 fix_desc64((void *) &master_gdt[sel_idx(USER_LDT)], 1);
 409                 fix_desc64((void *) &master_gdt[sel_idx(KERNEL_TSS)], 1);
 410
 411                 /*
 412                  * Set the NMI/fault stacks as IST2/IST1 in the 64-bit TSS
 413                  */
 414                 master_ktss64.ist2 = (uintptr_t) low_eintstack;
 415                 master_ktss64.ist1 = (uintptr_t) low_eintstack - sizeof(x86_64_intr_stack_frame_t);
 416         } else if (cdi->cdi_ktssu == NULL) {    /* Skipping re-init on wake */
 417                 cpu_desc_table64_t      *cdt = (cpu_desc_table64_t *) cdp->cpu_desc_tablep;
 418
 419                 cdi->cdi_idtu.ptr  = (void *)DBLMAP((uintptr_t) &master_idt64);
 420
 421                 cdi->cdi_ktssu = (void *)DBLMAP(&cdt->ktss);
 422                 cdi->cdi_ktssb = (void *)(&cdt->ktss);
 423                 cdi->cdi_sstku = (vm_offset_t)DBLMAP(&cdt->sstk.top);
 424                 cdi->cdi_sstkb = (vm_offset_t)(&cdt->sstk.top);
 425                 cdi->cdi_ldtu  = (void *)LDTALIAS(cdp->cpu_ldtp);
 426                 cdi->cdi_ldtb  = (void *)(cdp->cpu_ldtp);
 427
 428                 /*
 429                  * Copy the tables
 430                  */
 431                 bcopy((char *)master_gdt, (char *)cdt->gdt, sizeof(master_gdt));
 432                 bcopy((char *)master_ldt, (char *)cdp->cpu_ldtp, mldtsz);
 433                 bcopy((char *)&master_ktss64, (char *)&cdt->ktss, sizeof(struct x86_64_tss));
 434                 cdi->cdi_gdtu.ptr  = (void *)DBLMAP(cdt->gdt);
 435                 cdi->cdi_gdtb.ptr  = (void *)(cdt->gdt);
 436                 /*
 437                  * Fix up the entries in the GDT to point to
 438                  * this LDT and this TSS.
 439                  * Note reuse of global 'kernel_ldt_desc64, which is not
 440                  * concurrency-safe. Higher level synchronization is expected
 441                  */
 442                 kernel_ldt_desc64.offset64 = (uintptr_t) cdi->cdi_ldtu;
 443                 *(struct fake_descriptor64 *) &cdt->gdt[sel_idx(KERNEL_LDT)] =
 444                     kernel_ldt_desc64;
 445                 fix_desc64(&cdt->gdt[sel_idx(KERNEL_LDT)], 1);
 446
 447                 kernel_ldt_desc64.offset64 = (uintptr_t) cdi->cdi_ldtu;
 448                 *(struct fake_descriptor64 *) &cdt->gdt[sel_idx(USER_LDT)] =
 449                     kernel_ldt_desc64;
 450                 fix_desc64(&cdt->gdt[sel_idx(USER_LDT)], 1);
 451
 452                 kernel_tss_desc64.offset64 = (uintptr_t) cdi->cdi_ktssu;
 453                 *(struct fake_descriptor64 *) &cdt->gdt[sel_idx(KERNEL_TSS)] =
 454                     kernel_tss_desc64;
 455                 fix_desc64(&cdt->gdt[sel_idx(KERNEL_TSS)], 1);
 456
 457                 /* Set (zeroed) fault stack as IST1, NMI intr stack IST2 */
 458                 uint8_t *cfstk = &scfstks[cdp->cpu_number].fstk[0];
 459                 cdt->fstkp = cfstk;
 460                 bzero((void *) cfstk, FSTK_SZ);
 461                 cdt->ktss.ist2 = DBLMAP((uint64_t)cdt->fstkp + FSTK_SZ);
 462                 cdt->ktss.ist1 = cdt->ktss.ist2 - sizeof(x86_64_intr_stack_frame_t);
 463         }
 464
 465         /* Require that the top of the sysenter stack is 16-byte aligned */
 466         if ((cdi->cdi_sstku % 16) != 0) {
 467                 panic("cpu_desc_init() sysenter stack not 16-byte aligned");
 468         }
 469 }
 470 void
 471 cpu_desc_load(cpu_data_t *cdp)
 472 {
 473         cpu_desc_index_t        *cdi = &cdp->cpu_desc_index;
 474
 475         postcode(CPU_DESC_LOAD_ENTRY);
 476
 477         /* Stuff the kernel per-cpu data area address into the MSRs */
 478         postcode(CPU_DESC_LOAD_GS_BASE);
 479         wrmsr64(MSR_IA32_GS_BASE, (uintptr_t) cdp);
 480         postcode(CPU_DESC_LOAD_KERNEL_GS_BASE);
 481         wrmsr64(MSR_IA32_KERNEL_GS_BASE, (uintptr_t) cdp);
 482
 483         /*
 484          * Ensure the TSS segment's busy bit is clear. This is required
 485          * for the case of reloading descriptors at wake to avoid
 486          * their complete re-initialization.
 487          */
 488         gdt_desc_p(KERNEL_TSS)->access &= ~ACC_TSS_BUSY;
 489
 490         /* Load the GDT, LDT, IDT and TSS */
 491         cdi->cdi_gdtb.size = sizeof(struct real_descriptor) * GDTSZ - 1;
 492         cdi->cdi_gdtu.size = cdi->cdi_gdtb.size;
 493         cdi->cdi_idtb.size = 0x1000 + cdp->cpu_number;
 494         cdi->cdi_idtu.size = cdi->cdi_idtb.size;
 495
 496         postcode(CPU_DESC_LOAD_GDT);
 497         lgdt((uintptr_t *) &cdi->cdi_gdtu);
 498         postcode(CPU_DESC_LOAD_IDT);
 499         lidt((uintptr_t *) &cdi->cdi_idtu);
 500         postcode(CPU_DESC_LOAD_LDT);
 501         lldt(KERNEL_LDT);
 502         postcode(CPU_DESC_LOAD_TSS);
 503         set_tr(KERNEL_TSS);
 504
 505         postcode(CPU_DESC_LOAD_EXIT);
 506 }
 507
 508 /*
 509  * Set MSRs for sysenter/sysexit and syscall/sysret for 64-bit.
 510  */
 511 void
 512 cpu_syscall_init(cpu_data_t *cdp)
 513 {
 514 #pragma unused(cdp)
 515
 516         wrmsr64(MSR_IA32_SYSENTER_CS, SYSENTER_CS);
 517         wrmsr64(MSR_IA32_SYSENTER_EIP, DBLMAP((uintptr_t) hi64_sysenter));
 518         wrmsr64(MSR_IA32_SYSENTER_ESP, current_cpu_datap()->cpu_desc_index.cdi_sstku);
 519         /* Enable syscall/sysret */
 520         wrmsr64(MSR_IA32_EFER, rdmsr64(MSR_IA32_EFER) | MSR_IA32_EFER_SCE);
 521
 522         /*
 523          * MSRs for 64-bit syscall/sysret
 524          * Note USER_CS because sysret uses this + 16 when returning to
 525          * 64-bit code.
 526          */
 527         wrmsr64(MSR_IA32_LSTAR, DBLMAP((uintptr_t) hi64_syscall));
 528         wrmsr64(MSR_IA32_STAR, (((uint64_t)USER_CS) << 48) | (((uint64_t)KERNEL64_CS) << 32));
 529         /*
 530          * Emulate eflags cleared by sysenter but note that
 531          * we also clear the trace trap to avoid the complications
 532          * of single-stepping into a syscall. The nested task bit
 533          * is also cleared to avoid a spurious "task switch"
 534          * should we choose to return via an IRET.
 535          */
 536         wrmsr64(MSR_IA32_FMASK, EFL_DF | EFL_IF | EFL_TF | EFL_NT);
 537 }
 538 extern vm_offset_t dyn_dblmap(vm_offset_t, vm_offset_t);
 539 uint64_t ldt_alias_offset;
 540
 541 __startup_func
 542 static void
 543 cpu_data_startup_init(void)
 544 {
 545         int flags = KMA_GUARD_FIRST | KMA_GUARD_LAST | KMA_PERMANENT |
 546             KMA_ZERO | KMA_KOBJECT;
 547         uint32_t cpus = max_cpus_from_firmware;
 548         vm_size_t size = percpu_section_size() * cpus;
 549         kern_return_t kr;
 550
 551         percpu_base.size = percpu_section_size();
 552         if (cpus == 0) {
 553                 panic("percpu: max_cpus_from_firmware not yet initialized");
 554         }
 555         if (cpus == 1) {
 556                 percpu_base.start = VM_MAX_KERNEL_ADDRESS;
 557                 return;
 558         }
 559
 560         kr = kmem_alloc_flags(kernel_map, &percpu_base.start,
 561             round_page(size) + 2 * PAGE_SIZE, VM_KERN_MEMORY_CPU, flags);
 562         if (kr != KERN_SUCCESS) {
 563                 panic("percpu: kmem_alloc failed (%d)", kr);
 564         }
 565
 566         percpu_base.start += PAGE_SIZE - percpu_section_start();
 567         percpu_base.end    = percpu_base.start + size - 1;
 568 }
 569 STARTUP(PERCPU, STARTUP_RANK_FIRST, cpu_data_startup_init);
 570
 571 cpu_data_t *
 572 cpu_data_alloc(boolean_t is_boot_cpu)
 573 {
 574         int             ret;
 575         cpu_data_t      *cdp;
 576
 577         if (is_boot_cpu) {
 578                 assert(real_ncpus == 1);
 579                 cdp = cpu_datap(0);
 580                 if (cdp->cpu_processor == NULL) {
 581                         simple_lock_init(&ncpus_lock, 0);
 582                         cdp->cpu_processor = PERCPU_GET_MASTER(processor);
 583                 }
 584                 return cdp;
 585         }
 586
 587         boolean_t do_ldt_alloc = FALSE;
 588         simple_lock(&ncpus_lock, LCK_GRP_NULL);
 589         int cnum = real_ncpus;
 590         real_ncpus++;
 591         if (dyn_ldts == NULL) {
 592                 do_ldt_alloc = TRUE;
 593         }
 594         simple_unlock(&ncpus_lock);
 595
 596         /*
 597          * Allocate per-cpu data:
 598          */
 599
 600         cdp = &scdatas[cnum];
 601         bzero((void*) cdp, sizeof(cpu_data_t));
 602         cdp->cpu_this = cdp;
 603         cdp->cpu_number = cnum;
 604         cdp->cd_shadow = &cpshadows[cnum];
 605         cdp->cpu_pcpu_base = percpu_base.start + (cnum - 1) * percpu_section_size();
 606         cdp->cpu_processor = PERCPU_GET_WITH_BASE(cdp->cpu_pcpu_base, processor);
 607
 608         /*
 609          * Allocate interrupt stack:
 610          */
 611         ret = kmem_alloc(kernel_map,
 612             (vm_offset_t *) &cdp->cpu_int_stack_top,
 613             INTSTACK_SIZE, VM_KERN_MEMORY_CPU);
 614         if (ret != KERN_SUCCESS) {
 615                 panic("cpu_data_alloc() int stack failed, ret=%d\n", ret);
 616         }
 617         bzero((void*) cdp->cpu_int_stack_top, INTSTACK_SIZE);
 618         cdp->cpu_int_stack_top += INTSTACK_SIZE;
 619
 620         /*
 621          * Allocate descriptor table:
 622          */
 623
 624         cdp->cpu_desc_tablep = (struct cpu_desc_table *) &scdtables[cnum];
 625         /*
 626          * Allocate LDT
 627          */
 628         if (do_ldt_alloc) {
 629                 boolean_t do_ldt_free = FALSE;
 630                 vm_offset_t sldtoffset = 0;
 631                 /*
 632                  * Allocate LDT
 633                  */
 634                 vm_offset_t ldtalloc = 0, ldtallocsz = round_page_64(MAX_CPUS * sizeof(struct real_descriptor) * LDTSZ);
 635                 ret = kmem_alloc(kernel_map, (vm_offset_t *) &ldtalloc, ldtallocsz, VM_KERN_MEMORY_CPU);
 636                 if (ret != KERN_SUCCESS) {
 637                         panic("cpu_data_alloc() ldt failed, kmem_alloc=%d\n", ret);
 638                 }
 639
 640                 simple_lock(&ncpus_lock, LCK_GRP_NULL);
 641                 if (dyn_ldts == NULL) {
 642                         dyn_ldts = (cldt_t *)ldtalloc;
 643                 } else {
 644                         do_ldt_free = TRUE;
 645                 }
 646                 simple_unlock(&ncpus_lock);
 647
 648                 if (do_ldt_free) {
 649                         kmem_free(kernel_map, ldtalloc, ldtallocsz);
 650                 } else {
 651                         /* CPU registration and startup are expected to execute
 652                          * serially, as invoked by the platform driver.
 653                          * Create trampoline alias of LDT region.
 654                          */
 655                         sldtoffset = dyn_dblmap(ldtalloc, ldtallocsz);
 656                         ldt_alias_offset = sldtoffset;
 657                 }
 658         }
 659         cdp->cpu_ldtp = &dyn_ldts[cnum].pcldts[0];
 660
 661 #if CONFIG_MCA
 662         /* Machine-check shadow register allocation. */
 663         mca_cpu_alloc(cdp);
 664 #endif
 665
 666         /*
 667          * Before this cpu has been assigned a real thread context,
 668          * we give it a fake, unique, non-zero thread id which the locking
 669          * primitives use as their lock value.
 670          * Note that this does not apply to the boot processor, cpu 0, which
 671          * transitions to a thread context well before other processors are
 672          * started.
 673          */
 674         cdp->cpu_active_thread = (thread_t) (uintptr_t) cdp->cpu_number;
 675         cdp->cpu_NMI_acknowledged = TRUE;
 676         cdp->cpu_nanotime = &pal_rtc_nanotime_info;
 677
 678         kprintf("cpu_data_alloc(%d) %p desc_table: %p "
 679             "ldt: %p "
 680             "int_stack: 0x%lx-0x%lx\n",
 681             cdp->cpu_number, cdp, cdp->cpu_desc_tablep, cdp->cpu_ldtp,
 682             (long)(cdp->cpu_int_stack_top - INTSTACK_SIZE), (long)(cdp->cpu_int_stack_top));
 683         cpu_data_ptr[cnum] = cdp;
 684
 685         return cdp;
 686 }
 687
 688 boolean_t
 689 valid_user_data_selector(uint16_t selector)
 690 {
 691         sel_t       sel = selector_to_sel(selector);
 692
 693         if (selector == 0) {
 694                 return TRUE;
 695         }
 696
 697         if (sel.ti == SEL_LDT) {
 698                 return TRUE;
 699         } else if (sel.index < GDTSZ) {
 700                 if ((gdt_desc_p(selector)->access & ACC_PL_U) == ACC_PL_U) {
 701                         return TRUE;
 702                 }
 703         }
 704         return FALSE;
 705 }
 706
 707 boolean_t
 708 valid_user_code_selector(uint16_t selector)
 709 {
 710         sel_t       sel = selector_to_sel(selector);
 711
 712         if (selector == 0) {
 713                 return FALSE;
 714         }
 715
 716         if (sel.ti == SEL_LDT) {
 717                 if (sel.rpl == USER_PRIV) {
 718                         return TRUE;
 719                 }
 720         } else if (sel.index < GDTSZ && sel.rpl == USER_PRIV) {
 721                 if ((gdt_desc_p(selector)->access & ACC_PL_U) == ACC_PL_U) {
 722                         return TRUE;
 723                 }
 724                 /* Explicitly validate the system code selectors
 725                  * even if not instantaneously privileged,
 726                  * since they are dynamically re-privileged
 727                  * at context switch
 728                  */
 729                 if ((selector == USER_CS) || (selector == USER64_CS)) {
 730                         return TRUE;
 731                 }
 732         }
 733
 734         return FALSE;
 735 }
 736
 737 boolean_t
 738 valid_user_stack_selector(uint16_t selector)
 739 {
 740         sel_t       sel = selector_to_sel(selector);
 741
 742         if (selector == 0) {
 743                 return FALSE;
 744         }
 745
 746         if (sel.ti == SEL_LDT) {
 747                 if (sel.rpl == USER_PRIV) {
 748                         return TRUE;
 749                 }
 750         } else if (sel.index < GDTSZ && sel.rpl == USER_PRIV) {
 751                 if ((gdt_desc_p(selector)->access & ACC_PL_U) == ACC_PL_U) {
 752                         return TRUE;
 753                 }
 754         }
 755
 756         return FALSE;
 757 }
 758
 759 boolean_t
 760 valid_user_segment_selectors(uint16_t cs,
 761     uint16_t ss,
 762     uint16_t ds,
 763     uint16_t es,
 764     uint16_t fs,
 765     uint16_t gs)
 766 {
 767         return valid_user_code_selector(cs) &&
 768                valid_user_stack_selector(ss) &&
 769                valid_user_data_selector(ds) &&
 770                valid_user_data_selector(es) &&
 771                valid_user_data_selector(fs) &&
 772                valid_user_data_selector(gs);
 773 }
 774
 775 /*
 776  * Allocate a new interrupt stack for the boot processor from the
 777  * heap rather than continue to use the statically allocated space.
 778  * Also switch to a dynamically allocated cpu data area.
 779  */
 780 void
 781 cpu_data_realloc(void)
 782 {
 783         int             ret;
 784         vm_offset_t     istk;
 785         cpu_data_t      *cdp;
 786         boolean_t       istate;
 787
 788         ret = kmem_alloc(kernel_map, &istk, INTSTACK_SIZE, VM_KERN_MEMORY_CPU);
 789         if (ret != KERN_SUCCESS) {
 790                 panic("cpu_data_realloc() stack alloc, ret=%d\n", ret);
 791         }
 792         bzero((void*) istk, INTSTACK_SIZE);
 793         istk += INTSTACK_SIZE;
 794
 795         cdp = &scdatas[0];
 796
 797         /* Copy old contents into new area and make fix-ups */
 798         assert(cpu_number() == 0);
 799         bcopy((void *) cpu_data_ptr[0], (void*) cdp, sizeof(cpu_data_t));
 800         cdp->cpu_this = cdp;
 801         cdp->cpu_int_stack_top = istk;
 802         timer_call_queue_init(&cdp->rtclock_timer.queue);
 803         cdp->cpu_desc_tablep = (struct cpu_desc_table *) &scdtables[0];
 804         cpu_desc_table64_t      *cdt = (cpu_desc_table64_t *) cdp->cpu_desc_tablep;
 805
 806         uint8_t *cfstk = &scfstks[cdp->cpu_number].fstk[0];
 807         cdt->fstkp = cfstk;
 808         cfstk += FSTK_SZ;
 809
 810         /*
 811          * With interrupts disabled commmit the new areas.
 812          */
 813         istate = ml_set_interrupts_enabled(FALSE);
 814         cpu_data_ptr[0] = cdp;
 815         master_ktss64.ist2 = DBLMAP((uintptr_t) cfstk);
 816         master_ktss64.ist1 = DBLMAP((uintptr_t) cfstk - sizeof(x86_64_intr_stack_frame_t));
 817         wrmsr64(MSR_IA32_GS_BASE, (uintptr_t) cdp);
 818         wrmsr64(MSR_IA32_KERNEL_GS_BASE, (uintptr_t) cdp);
 819         (void) ml_set_interrupts_enabled(istate);
 820
 821         kprintf("Reallocated master cpu data: %p,"
 822             " interrupt stack: %p, fault stack: %p\n",
 823             (void *) cdp, (void *) istk, (void *) cfstk);
 824 }