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