src/runtime/x86-64-darwin-os.c

   1 #ifdef LISP_FEATURE_SB_THREAD
   2 #include <architecture/i386/table.h>
   3 #include <i386/user_ldt.h>
   4 #include <mach/mach_init.h>
   5 #endif
   6
   7 #include "thread.h"
   8 #include "validate.h"
   9 #include "runtime.h"
  10 #include "interrupt.h"
  11 #include "x86-64-darwin-os.h"
  12 #include "genesis/fdefn.h"
  13
  14 #include <mach/mach.h>
  15 #include <mach/mach_error.h>
  16 #include <mach/mach_types.h>
  17 #include <mach/sync_policy.h>
  18 #include <mach/machine/thread_state.h>
  19 #include <mach/machine/thread_status.h>
  20 #include <sys/_types.h>
  21 #include <sys/ucontext.h>
  22 #include <pthread.h>
  23 #include <assert.h>
  24 #include <stdlib.h>
  25 #include <stdio.h>
  26
  27 #if __DARWIN_UNIX03
  28 #include <sys/_structs.h>
  29 #endif
  30
  31 #if __DARWIN_UNIX03
  32
  33 typedef struct __darwin_ucontext darwin_ucontext;
  34 typedef struct __darwin_mcontext64 darwin_mcontext;
  35
  36 #define rip __rip
  37 #define rsp __rsp
  38 #define rbp __rbp
  39 #define rax __rax
  40 #define rbx __rbx
  41 #define rcx __rcx
  42 #define rdx __rdx
  43 #define rsi __rsi
  44 #define rdi __rdi
  45 #define r8 __r8
  46 #define r9 __r9
  47 #define faultvaddr __faultvaddr
  48 #define ss __ss
  49 #define es __es
  50 #define fs __fs
  51
  52 #define fpu_fcw __fpu_fcw
  53 #define fpu_mxcsr __fpu_mxcsr
  54
  55 #else
  56
  57 typedef struct ucontext darwin_ucontext;
  58 typedef struct mcontext darwin_mcontext;
  59
  60 #endif
  61
  62 #ifdef LISP_FEATURE_SB_THREAD
  63 pthread_mutex_t mach_exception_lock = PTHREAD_MUTEX_INITIALIZER;
  64 #endif
  65
  66 #ifdef LISP_FEATURE_MACH_EXCEPTION_HANDLER
  67
  68 void sigill_handler(int signal, siginfo_t *siginfo, os_context_t *context);
  69 void sigtrap_handler(int signal, siginfo_t *siginfo, os_context_t *context);
  70 void memory_fault_handler(int signal, siginfo_t *siginfo,
  71                           os_context_t *context);
  72
  73 /* This executes in the faulting thread as part of the signal
  74  * emulation.  It is passed a context with the uc_mcontext field
  75  * pointing to a valid block of memory. */
  76 void build_fake_signal_context(darwin_ucontext *context,
  77                                x86_thread_state64_t *thread_state,
  78                                x86_float_state64_t *float_state) {
  79     pthread_sigmask(0, NULL, &context->uc_sigmask);
  80     context->uc_mcontext->ss = *thread_state;
  81     context->uc_mcontext->fs = *float_state;
  82 }
  83
  84 /* This executes in the faulting thread as part of the signal
  85  * emulation.  It is effectively the inverse operation from above. */
  86 void update_thread_state_from_context(x86_thread_state64_t *thread_state,
  87                                       x86_float_state64_t *float_state,
  88                                       darwin_ucontext  *context) {
  89     *thread_state = context->uc_mcontext->ss;
  90     *float_state = context->uc_mcontext->fs;
  91     pthread_sigmask(SIG_SETMASK, &context->uc_sigmask, NULL);
  92 }
  93
  94 /* Modify a context to push new data on its stack. */
  95 void push_context(u64 data, x86_thread_state64_t *context)
  96 {
  97     u64 *stack_pointer;
  98
  99     stack_pointer = (u64*) context->rsp;
 100     *(--stack_pointer) = data;
 101     context->rsp = (u64) stack_pointer;
 102 }
 103
 104 void align_context_stack(x86_thread_state64_t *context)
 105 {
 106     /* 16byte align the stack (provided that the stack is, as it
 107      * should be, 8byte aligned. */
 108     while (context->rsp & 15) push_context(0, context);
 109 }
 110
 111 /* Stack allocation starts with a context that has a mod-4 ESP value
 112  * and needs to leave a context with a mod-16 ESP that will restore
 113  * the old ESP value and other register state when activated.  The
 114  * first part of this is the recovery trampoline, which loads ESP from
 115  * EBP, pops EBP, and returns. */
 116 asm(".globl _stack_allocation_recover; \
 117     .align 4; \
 118  _stack_allocation_recover: \
 119     lea -48(%rbp), %rsp; \
 120     pop %rsi; \
 121     pop %rdi; \
 122     pop %rdx; \
 123     pop %rcx; \
 124     pop %r8; \
 125     pop %r9; \
 126     pop %rbp; \
 127     ret;");
 128
 129 void open_stack_allocation(x86_thread_state64_t *context)
 130 {
 131     void stack_allocation_recover(void);
 132
 133     push_context(context->rip, context);
 134     push_context(context->rbp, context);
 135     context->rbp = context->rsp;
 136
 137     push_context(context->r9, context);
 138     push_context(context->r8, context);
 139     push_context(context->rcx, context);
 140     push_context(context->rdx, context);
 141     push_context(context->rsi, context);
 142     push_context(context->rdi, context);
 143
 144     context->rip = (u64) stack_allocation_recover;
 145
 146     align_context_stack(context);
 147 }
 148
 149 /* Stack allocation of data starts with a context with a mod-16 ESP
 150  * value and reserves some space on it by manipulating the ESP
 151  * register. */
 152 void *stack_allocate(x86_thread_state64_t *context, size_t size)
 153 {
 154     /* round up size to 16byte multiple */
 155     size = (size + 15) & -16;
 156
 157     context->rsp = ((u64)context->rsp) - size;
 158
 159     return (void *)context->rsp;
 160 }
 161
 162 /* Arranging to invoke a C function is tricky, as we have to assume
 163  * cdecl calling conventions (caller removes args) and x86/darwin
 164  * alignment requirements.  The simplest way to arrange this,
 165  * actually, is to open a new stack allocation.
 166  * WARNING!!! THIS DOES NOT PRESERVE REGISTERS! */
 167 void call_c_function_in_context(x86_thread_state64_t *context,
 168                                 void *function,
 169                                 int nargs,
 170                                 ...)
 171 {
 172     va_list ap;
 173     int i;
 174     u64 *stack_pointer;
 175
 176     /* Set up to restore stack on exit. */
 177     open_stack_allocation(context);
 178
 179     /* Have to keep stack 16byte aligned on x86/darwin. */
 180     for (i = (1 & -nargs); i; i--) {
 181         push_context(0, context);
 182     }
 183
 184     context->rsp = ((u64)context->rsp) - nargs * 8;
 185     stack_pointer = (u64 *)context->rsp;
 186
 187     va_start(ap, nargs);
 188     if (nargs > 0) context->rdi = va_arg(ap, u64);
 189     if (nargs > 1) context->rsi = va_arg(ap, u64);
 190     if (nargs > 2) context->rdx = va_arg(ap, u64);
 191     if (nargs > 3) context->rcx = va_arg(ap, u64);
 192     if (nargs > 4) context->r8 = va_arg(ap, u64);
 193     if (nargs > 5) context->r9 = va_arg(ap, u64);
 194     for (i = 6; i < nargs; i++) {
 195         stack_pointer[i] = va_arg(ap, u64);
 196     }
 197     va_end(ap);
 198
 199     push_context(context->rip, context);
 200     context->rip = (u64) function;
 201 }
 202
 203 void signal_emulation_wrapper(x86_thread_state64_t *thread_state,
 204                               x86_float_state64_t *float_state,
 205                               int signal,
 206                               siginfo_t *siginfo,
 207                               void (*handler)(int, siginfo_t *, void *))
 208 {
 209
 210     /* CLH: FIXME **NOTE: HACK ALERT!** Ideally, we would allocate
 211      * context and regs on the stack as local variables, but this
 212      * causes problems for the lisp debugger. When it walks the stack
 213      * for a back trace, it sees the 1) address of the local variable
 214      * on the stack and thinks that is a frame pointer to a lisp
 215      * frame, and, 2) the address of the sap that we alloc'ed in
 216      * dynamic space and thinks that is a return address, so it,
 217      * heuristicly (and wrongly), chooses that this should be
 218      * interpreted as a lisp frame instead of as a C frame.
 219      * We can work around this in this case by os_validating the
 220      * context (and regs just for symmetry).
 221      */
 222
 223     darwin_ucontext  *context;
 224     darwin_mcontext *regs;
 225
 226     context = (darwin_ucontext *) os_validate(0, sizeof(darwin_ucontext));
 227     regs = (darwin_mcontext*) os_validate(0, sizeof(darwin_mcontext));
 228     context->uc_mcontext = regs;
 229
 230     /* when BSD signals are fired, they mask they signals in sa_mask
 231        which always seem to be the blockable_sigset, for us, so we
 232        need to:
 233        1) save the current sigmask
 234        2) block blockable signals
 235        3) call the signal handler
 236        4) restore the sigmask */
 237
 238     build_fake_signal_context(context, thread_state, float_state);
 239
 240     block_blockable_signals(0, 0);
 241
 242     handler(signal, siginfo, context);
 243
 244     update_thread_state_from_context(thread_state, float_state, context);
 245
 246     os_invalidate((os_vm_address_t)context, sizeof(darwin_ucontext));
 247     os_invalidate((os_vm_address_t)regs, sizeof(darwin_mcontext));
 248
 249     /* Trap to restore the signal context. */
 250     asm volatile (".quad 0xffffffffffff0b0f"
 251                   : : "a" (thread_state), "b" (float_state));
 252 }
 253
 254 #if defined DUMP_CONTEXT
 255 void dump_context(x86_thread_state64_t *context)
 256 {
 257     int i;
 258     u64 *stack_pointer;
 259
 260     printf("rax: %08lx  rcx: %08lx  rdx: %08lx  rbx: %08lx\n",
 261            context->rax, context->rcx, context->rdx, context->rbx);
 262     printf("rsp: %08lx  rbp: %08lx  rsi: %08lx  rdi: %08lx\n",
 263            context->rsp, context->rbp, context->rsi, context->rdi);
 264     printf("rip: %08lx  eflags: %08lx\n",
 265            context->rip, context->rflags);
 266     printf("cs: %04hx  ds: %04hx  es: %04hx  "
 267            "ss: %04hx  fs: %04hx  gs: %04hx\n",
 268            context->cs, context->ds, context->rs,
 269            context->ss, context->fs, context->gs);
 270
 271     stack_pointer = (u64 *)context->rsp;
 272     for (i = 0; i < 48; i+=4) {
 273         printf("%08x:  %08x %08x %08x %08x\n",
 274                context->rsp + (i * 4),
 275                stack_pointer[i],
 276                stack_pointer[i+1],
 277                stack_pointer[i+2],
 278                stack_pointer[i+3]);
 279     }
 280 }
 281 #endif
 282
 283 void
 284 control_stack_exhausted_handler(int signal, siginfo_t *siginfo,
 285                                 os_context_t *context) {
 286     unblock_signals_in_context_and_maybe_warn(context);
 287     arrange_return_to_lisp_function
 288         (context, StaticSymbolFunction(CONTROL_STACK_EXHAUSTED_ERROR));
 289 }
 290
 291 void
 292 undefined_alien_handler(int signal, siginfo_t *siginfo, os_context_t *context) {
 293     arrange_return_to_lisp_function
 294         (context, StaticSymbolFunction(UNDEFINED_ALIEN_VARIABLE_ERROR));
 295 }
 296
 297 kern_return_t
 298 catch_exception_raise(mach_port_t exception_port,
 299                       mach_port_t thread,
 300                       mach_port_t task,
 301                       exception_type_t exception,
 302                       exception_data_t code_vector,
 303                       mach_msg_type_number_t code_count)
 304 {
 305     kern_return_t ret, dealloc_ret;
 306     int signal;
 307     siginfo_t* siginfo;
 308
 309 #ifdef LISP_FEATURE_SB_THREAD
 310     thread_mutex_lock(&mach_exception_lock);
 311 #endif
 312
 313     x86_thread_state64_t thread_state;
 314     mach_msg_type_number_t thread_state_count = x86_THREAD_STATE64_COUNT;
 315
 316     x86_float_state64_t float_state;
 317     mach_msg_type_number_t float_state_count = x86_FLOAT_STATE64_COUNT;
 318
 319     x86_exception_state64_t exception_state;
 320     mach_msg_type_number_t exception_state_count = x86_EXCEPTION_STATE64_COUNT;
 321
 322     x86_thread_state64_t backup_thread_state;
 323     x86_thread_state64_t *target_thread_state;
 324     x86_float_state64_t *target_float_state;
 325
 326     os_vm_address_t addr;
 327
 328     struct thread *th = (struct thread*) exception_port;
 329
 330     FSHOW((stderr,"/entering catch_exception_raise with exception: %d\n", exception));
 331
 332     switch (exception) {
 333
 334     case EXC_BAD_ACCESS:
 335         signal = SIGBUS;
 336         ret = thread_get_state(thread,
 337                                x86_THREAD_STATE64,
 338                                (thread_state_t)&thread_state,
 339                                &thread_state_count);
 340         ret = thread_get_state(thread,
 341                                x86_FLOAT_STATE64,
 342                                (thread_state_t)&float_state,
 343                                &float_state_count);
 344         ret = thread_get_state(thread,
 345                                x86_EXCEPTION_STATE64,
 346                                (thread_state_t)&exception_state,
 347                                &exception_state_count);
 348         addr = (void*)exception_state.faultvaddr;
 349
 350
 351         /* note the os_context hackery here.  When the signal handler returns,
 352          * it won't go back to what it was doing ... */
 353         if(addr >= CONTROL_STACK_GUARD_PAGE(th) &&
 354            addr < CONTROL_STACK_GUARD_PAGE(th) + os_vm_page_size) {
 355             /* We hit the end of the control stack: disable guard page
 356              * protection so the error handler has some headroom, protect the
 357              * previous page so that we can catch returns from the guard page
 358              * and restore it. */
 359             lower_thread_control_stack_guard_page(th);
 360
 361             backup_thread_state = thread_state;
 362             open_stack_allocation(&thread_state);
 363             /* Reserve a 256 byte zone for signal handlers
 364              * to use on the interrupted thread stack.
 365              */
 366             stack_allocate(&thread_state, 256);
 367
 368             /* Save thread state */
 369             target_thread_state =
 370                 stack_allocate(&thread_state, sizeof(*target_thread_state));
 371             (*target_thread_state) = backup_thread_state;
 372
 373             /* Save float state */
 374             target_float_state =
 375                 stack_allocate(&thread_state, sizeof(*target_float_state));
 376             (*target_float_state) = float_state;
 377
 378             /* Set up siginfo */
 379             siginfo = stack_allocate(&thread_state, sizeof(*siginfo));
 380             /* what do we need to put in our fake siginfo?  It looks like
 381              * the x86 code only uses si_signo and si_adrr. */
 382             siginfo->si_signo = signal;
 383             siginfo->si_addr = (void*)exception_state.faultvaddr;
 384
 385             call_c_function_in_context(&thread_state,
 386                                        signal_emulation_wrapper,
 387                                        5,
 388                                        target_thread_state,
 389                                        target_float_state,
 390                                        signal,
 391                                        siginfo,
 392                                        control_stack_exhausted_handler);
 393         }
 394         else if(addr >= CONTROL_STACK_RETURN_GUARD_PAGE(th) &&
 395                 addr < CONTROL_STACK_RETURN_GUARD_PAGE(th) + os_vm_page_size) {
 396             /* We're returning from the guard page: reprotect it, and
 397              * unprotect this one. This works even if we somehow missed
 398              * the return-guard-page, and hit it on our way to new
 399              * exhaustion instead. */
 400             reset_thread_control_stack_guard_page(th);
 401         }
 402         else if (addr >= undefined_alien_address &&
 403                  addr < undefined_alien_address + os_vm_page_size) {
 404             backup_thread_state = thread_state;
 405             open_stack_allocation(&thread_state);
 406             stack_allocate(&thread_state, 256);
 407
 408             /* Save thread state */
 409             target_thread_state =
 410                 stack_allocate(&thread_state, sizeof(*target_thread_state));
 411             (*target_thread_state) = backup_thread_state;
 412
 413             target_float_state =
 414                 stack_allocate(&thread_state, sizeof(*target_float_state));
 415             (*target_float_state) = float_state;
 416
 417             /* Set up siginfo */
 418             siginfo = stack_allocate(&thread_state, sizeof(*siginfo));
 419             /* what do we need to put in our fake siginfo?  It looks like
 420              * the x86 code only uses si_signo and si_adrr. */
 421             siginfo->si_signo = signal;
 422             siginfo->si_addr = (void*)exception_state.faultvaddr;
 423
 424             call_c_function_in_context(&thread_state,
 425                                        signal_emulation_wrapper,
 426                                        5,
 427                                        target_thread_state,
 428                                        target_float_state,
 429                                        signal,
 430                                        siginfo,
 431                                        undefined_alien_handler);
 432         } else {
 433
 434             backup_thread_state = thread_state;
 435             open_stack_allocation(&thread_state);
 436             stack_allocate(&thread_state, 256);
 437
 438             /* Save thread state */
 439             target_thread_state =
 440                 stack_allocate(&thread_state, sizeof(*target_thread_state));
 441             (*target_thread_state) = backup_thread_state;
 442
 443             target_float_state =
 444                 stack_allocate(&thread_state, sizeof(*target_float_state));
 445             (*target_float_state) = float_state;
 446
 447             /* Set up siginfo */
 448             siginfo = stack_allocate(&thread_state, sizeof(*siginfo));
 449             /* what do we need to put in our fake siginfo?  It looks like
 450              * the x86 code only uses si_signo and si_adrr. */
 451             siginfo->si_signo = signal;
 452             siginfo->si_addr = (void*)exception_state.faultvaddr;
 453
 454             call_c_function_in_context(&thread_state,
 455                                        signal_emulation_wrapper,
 456                                        5,
 457                                        target_thread_state,
 458                                        target_float_state,
 459                                        signal,
 460                                        siginfo,
 461                                        memory_fault_handler);
 462         }
 463         ret = thread_set_state(thread,
 464                                x86_THREAD_STATE64,
 465                                (thread_state_t)&thread_state,
 466                                thread_state_count);
 467
 468         ret = thread_set_state(thread,
 469                                x86_FLOAT_STATE64,
 470                                (thread_state_t)&float_state,
 471                                float_state_count);
 472 #ifdef LISP_FEATURE_SB_THREAD
 473         thread_mutex_unlock(&mach_exception_lock);
 474 #endif
 475         ret = KERN_SUCCESS;
 476         break;
 477
 478     case EXC_BAD_INSTRUCTION:
 479
 480         ret = thread_get_state(thread,
 481                                x86_THREAD_STATE64,
 482                                (thread_state_t)&thread_state,
 483                                &thread_state_count);
 484         ret = thread_get_state(thread,
 485                                x86_FLOAT_STATE64,
 486                                (thread_state_t)&float_state,
 487                                &float_state_count);
 488         ret = thread_get_state(thread,
 489                                x86_EXCEPTION_STATE64,
 490                                (thread_state_t)&exception_state,
 491                                &exception_state_count);
 492         if (0xffffffffffff0b0f == *((u64 *)thread_state.rip)) {
 493             /* fake sigreturn. */
 494
 495             /* When we get here, thread_state.rax is a pointer to a
 496              * thread_state to restore. */
 497             /* thread_state = *((thread_state_t *)thread_state.rax); */
 498
 499             ret = thread_set_state(thread,
 500                                    x86_THREAD_STATE64,
 501                                    (thread_state_t) thread_state.rax,
 502                                    /* &thread_state, */
 503                                    thread_state_count);
 504
 505             ret = thread_set_state(thread,
 506                                    x86_FLOAT_STATE64,
 507                                    (thread_state_t) thread_state.rbx,
 508                                    /* &thread_state, */
 509                                    float_state_count);
 510         } else {
 511
 512             backup_thread_state = thread_state;
 513             open_stack_allocation(&thread_state);
 514             stack_allocate(&thread_state, 256);
 515
 516             /* Save thread state */
 517             target_thread_state =
 518                 stack_allocate(&thread_state, sizeof(*target_thread_state));
 519             (*target_thread_state) = backup_thread_state;
 520
 521             target_float_state =
 522                 stack_allocate(&thread_state, sizeof(*target_float_state));
 523             (*target_float_state) = float_state;
 524
 525             /* Set up siginfo */
 526             siginfo = stack_allocate(&thread_state, sizeof(*siginfo));
 527             /* what do we need to put in our fake siginfo?  It looks like
 528              * the x86 code only uses si_signo and si_adrr. */
 529             if (*((unsigned short *)target_thread_state->rip) == 0x0b0f) {
 530                 signal = SIGTRAP;
 531                 siginfo->si_signo = signal;
 532                 siginfo->si_addr = (void*)exception_state.faultvaddr;
 533                 target_thread_state->rip += 2;
 534                 call_c_function_in_context(&thread_state,
 535                                            signal_emulation_wrapper,
 536                                            5,
 537                                            target_thread_state,
 538                                            target_float_state,
 539                                            signal,
 540                                            siginfo,
 541                                            sigtrap_handler);
 542             } else {
 543                 signal = SIGILL;
 544                 siginfo->si_signo = signal;
 545                 siginfo->si_addr = (void*)exception_state.faultvaddr;
 546
 547                 call_c_function_in_context(&thread_state,
 548                                            signal_emulation_wrapper,
 549                                            5,
 550                                            target_thread_state,
 551                                            target_float_state,
 552                                            signal,
 553                                            siginfo,
 554                                            sigill_handler);
 555             }
 556             ret = thread_set_state(thread,
 557                                    x86_THREAD_STATE64,
 558                                    (thread_state_t)&thread_state,
 559                                    thread_state_count);
 560             ret = thread_set_state(thread,
 561                                    x86_FLOAT_STATE64,
 562                                    (thread_state_t)&float_state,
 563                                    float_state_count);
 564         }
 565 #ifdef LISP_FEATURE_SB_THREAD
 566         thread_mutex_unlock(&mach_exception_lock);
 567 #endif
 568         ret = KERN_SUCCESS;
 569         break;
 570
 571     default:
 572 #ifdef LISP_FEATURE_SB_THREAD
 573         thread_mutex_unlock(&mach_exception_lock);
 574 #endif
 575         ret = KERN_INVALID_RIGHT;
 576     }
 577
 578     dealloc_ret = mach_port_deallocate (current_mach_task, thread);
 579     if (dealloc_ret) {
 580       lose("mach_port_deallocate (thread) failed with return_code %d\n", dealloc_ret);
 581     }
 582
 583     dealloc_ret = mach_port_deallocate (current_mach_task, task);
 584     if (dealloc_ret) {
 585       lose("mach_port_deallocate (task) failed with return_code %d\n", dealloc_ret);
 586     }
 587
 588     return ret;
 589 }
 590
 591 void
 592 os_restore_fp_control(os_context_t *context)
 593 {
 594     /* KLUDGE: The x87 FPU control word is some nasty bitfield struct
 595      * thing.  Rather than deal with that, just grab it as a 16-bit
 596      * integer. */
 597     unsigned short fpu_control_word =
 598         *((unsigned short *)&context->uc_mcontext->fs.fpu_fcw);
 599     /* reset exception flags and restore control flags on SSE2 FPU */
 600     unsigned int temp = (context->uc_mcontext->fs.fpu_mxcsr) & ~0x3F;
 601     asm ("ldmxcsr %0" : : "m" (temp));
 602     /* same for x87 FPU. */
 603     asm ("fldcw %0" : : "m" (fpu_control_word));
 604 }
 605
 606 #endif