git.m6w6.name Git - m6w6/ext-psi/blob - src/libffi.c

   1 #ifdef HAVE_CONFIG_H
   2 # include "config.h"
   3 #endif
   4
   5 #include "php.h"
   6
   7 #ifdef HAVE_LIBFFI
   8
   9 #include "php_psi.h"
  10 #include "libffi.h"
  11 #include "engine.h"
  12
  13 #undef PACKAGE
  14 #undef PACKAGE_BUGREPORT
  15 #undef PACKAGE_NAME
  16 #undef PACKAGE_STRING
  17 #undef PACKAGE_TARNAME
  18 #undef PACKAGE_VERSION
  19
  20 #include <ffi.h>
  21
  22 #ifndef PSI_HAVE_FFI_CLOSURE_ALLOC
  23 # if HAVE_UNISTD_H
  24 #  include <unistd.h>
  25 # endif
  26 # if HAVE_SYS_MMAN_H
  27 #  include <sys/mman.h>
  28 #  ifndef MAP_ANONYMOUS
  29 #   define MAP_ANONYMOUS MAP_ANON
  30 #  endif
  31 # endif
  32 #endif
  33
  34 static void *psi_ffi_closure_alloc(size_t s, void **code)
  35 {
  36 #ifdef PSI_HAVE_FFI_CLOSURE_ALLOC
  37         return ffi_closure_alloc(s, code);
  38 #elif HAVE_MMAP
  39         *code = mmap(NULL, s, PROT_EXEC|PROT_WRITE|PROT_READ,
  40                         MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
  41         if (MAP_FAILED == *code) {
  42                 return NULL;
  43         }
  44         return *code;
  45 #else
  46 # error "Neither ffi_closure_alloc() nor mmap() available"
  47 #endif
  48 }
  49
  50 static ffi_status psi_ffi_prep_closure(ffi_closure **closure, void **code, ffi_cif *sig, void (*handler)(ffi_cif*,void*,void**,void*), void *data) {
  51         *closure = psi_ffi_closure_alloc(sizeof(ffi_closure), code);
  52         ZEND_ASSERT(*closure != NULL);
  53
  54 #if PSI_HAVE_FFI_PREP_CLOSURE_LOC
  55         return ffi_prep_closure_loc(*closure, sig, handler, data, *code);
  56
  57 #elif PSI_HAVE_FFI_PREP_CLOSURE
  58         return ffi_prep_closure(*code, sig, handler, data);
  59 #else
  60 # error "Neither ffi_prep_closure() nor ffi_prep_closure_loc() is available"
  61 #endif
  62
  63 }
  64
  65 static void psi_ffi_closure_free(void *c)
  66 {
  67 #ifdef PSI_HAVE_FFI_CLOSURE_ALLOC
  68         ffi_closure_free(c);
  69 #elif HAVE_MMAP
  70         munmap(c, sizeof(ffi_closure));
  71 #endif
  72 }
  73
  74 static void psi_ffi_handler(ffi_cif *_sig, void *_result, void **_args, void *_data)
  75 {
  76         psi_call(*(zend_execute_data **)_args[0], *(zval **)_args[1], _data);
  77 }
  78
  79 static void psi_ffi_callback(ffi_cif *_sig, void *_result, void **_args, void *_data)
  80 {
  81         unsigned argc = _sig->nargs;
  82         void **argv = _args;
  83         ffi_arg *res = _result;
  84         let_stmt *let;
  85         decl_arg *darg = let->var->arg;
  86         decl *decl_cb = darg->type->func;
  87         let_callback *cb = let->val->data.callback;
  88         impl_arg *iarg = cb->func->arg;
  89         size_t i, argc = cb->args->count;
  90         zval *argv = calloc(argc, sizeof(*argv));
  91
  92         // prepare args for the userland call
  93         for (i = 0; i < decl_cb->args->count; ++i) {
  94
  95         }
  96         for (i = 0; i < cb->args->count; ++i) {
  97                 psi_do_set(&argv[i], cb->args->vals[i]);
  98         }
  99         zend_fcall_info_argp(iarg->val.zend.cb->fci, argc, argv);
 100         // marshal return value of the userland call
 101         darg->ptr = psi_let_val(cb->func->type, iarg, darg->ptr, real_decl_type(darg->type)->strct, &darg->mem);
 102 }
 103
 104 static inline ffi_type *psi_ffi_decl_arg_type(decl_arg *darg);
 105
 106 typedef struct PSI_LibffiContext {
 107         ffi_cif signature;
 108         ffi_type *params[2];
 109 } PSI_LibffiContext;
 110
 111 typedef struct PSI_LibffiCall {
 112         void *code;
 113         ffi_closure *closure;
 114         ffi_cif signature;
 115         void *params[1]; /* [type1, type2, NULL, arg1, arg2] ... */
 116 } PSI_LibffiCall;
 117
 118 static inline ffi_abi psi_ffi_abi(const char *convention) {
 119         return FFI_DEFAULT_ABI;
 120 }
 121
 122 static inline PSI_LibffiCall *PSI_LibffiCallAlloc(PSI_Context *C, decl *decl) {
 123         int rc;
 124         size_t i, c = decl->args ? decl->args->count : 0;
 125         PSI_LibffiCall *call = calloc(1, sizeof(*call) + 2 * c * sizeof(void *));
 126
 127         for (i = 0; i < c; ++i) {
 128                 call->params[i] = psi_ffi_decl_arg_type(decl->args->args[i]);
 129         }
 130         call->params[c] = NULL;
 131
 132         decl->call.info = call;
 133         decl->call.rval = &decl->func->ptr;
 134         decl->call.argc = c;
 135         decl->call.args = (void **) &call->params[c+1];
 136
 137         rc = ffi_prep_cif(&call->signature, psi_ffi_abi(decl->abi->convention),
 138                         c, psi_ffi_decl_arg_type(decl->func), (ffi_type **) call->params);
 139         ZEND_ASSERT(FFI_OK == rc);
 140
 141         return call;
 142 }
 143
 144 static inline void PSI_LibffiCallInitClosure(PSI_Context *C, PSI_LibffiCall *call, impl *impl) {
 145         PSI_LibffiContext *context = C->context;
 146         ffi_status rc;
 147
 148         rc = psi_ffi_prep_closure(&call->closure, &call->code, &context->signature, psi_ffi_handler, impl);
 149         ZEND_ASSERT(FFI_OK == rc);
 150 }
 151
 152 static inline void PSI_LibffiCallFree(PSI_LibffiCall *call) {
 153         if (call->closure) {
 154                 psi_ffi_closure_free(call->closure);
 155         }
 156         free(call);
 157 }
 158
 159 static inline ffi_type *psi_ffi_token_type(token_t t) {
 160         switch (t) {
 161         default:
 162                 ZEND_ASSERT(0);
 163                 /* no break */
 164         case PSI_T_VOID:
 165                 return &ffi_type_void;
 166         case PSI_T_INT8:
 167                 return &ffi_type_sint8;
 168         case PSI_T_UINT8:
 169                 return &ffi_type_uint8;
 170         case PSI_T_INT16:
 171                 return &ffi_type_sint16;
 172         case PSI_T_UINT16:
 173                 return &ffi_type_uint16;
 174         case PSI_T_INT32:
 175                 return &ffi_type_sint32;
 176         case PSI_T_UINT32:
 177                 return &ffi_type_uint32;
 178         case PSI_T_INT64:
 179                 return &ffi_type_sint64;
 180         case PSI_T_UINT64:
 181                 return &ffi_type_uint64;
 182         case PSI_T_BOOL:
 183                 return &ffi_type_uchar;
 184         case PSI_T_INT:
 185         case PSI_T_ENUM:
 186                 return &ffi_type_sint;
 187         case PSI_T_LONG:
 188                 return &ffi_type_slong;
 189         case PSI_T_FLOAT:
 190                 return &ffi_type_float;
 191         case PSI_T_DOUBLE:
 192                 return &ffi_type_double;
 193 #ifdef HAVE_LONG_DOUBLE
 194         case PSI_T_LONG_DOUBLE:
 195                 return &ffi_type_longdouble;
 196 #endif
 197         case PSI_T_POINTER:
 198         case PSI_T_FUNCTION:
 199                 return &ffi_type_pointer;
 200         }
 201 }
 202 static inline ffi_type *psi_ffi_impl_type(token_t impl_type) {
 203         switch (impl_type) {
 204         case PSI_T_BOOL:
 205                 return &ffi_type_sint8;
 206         case PSI_T_INT:
 207                 return &ffi_type_sint64;
 208         case PSI_T_STRING:
 209                 return &ffi_type_pointer;
 210         case PSI_T_FLOAT:
 211         case PSI_T_DOUBLE:
 212                 return &ffi_type_double;
 213         EMPTY_SWITCH_DEFAULT_CASE();
 214         }
 215         return NULL;
 216 }
 217 static void psi_ffi_struct_type_dtor(void *type) {
 218         ffi_type *strct = type;
 219
 220         if (strct->elements) {
 221                 ffi_type **ptr;
 222
 223                 for (ptr = strct->elements; *ptr; ++ptr) {
 224                         free(*ptr);
 225                 }
 226                 free(strct->elements);
 227         }
 228         free(strct);
 229 }
 230
 231 static size_t psi_ffi_struct_type_pad(ffi_type **els, size_t padding) {
 232         size_t i;
 233
 234         for (i = 0; i < padding; ++i) {
 235                 ffi_type *pad = malloc(sizeof(*pad));
 236
 237                 memcpy(pad, &ffi_type_schar, sizeof(*pad));
 238                 *els++ = pad;
 239         }
 240
 241         return padding;
 242 }
 243
 244 static ffi_type **psi_ffi_struct_type_elements(decl_struct *strct) {
 245         size_t i, argc = strct->args->count, nels = 0, offset = 0, maxalign = 0;
 246         ffi_type **els = calloc(argc + 1, sizeof(*els));
 247
 248         for (i = 0; i < strct->args->count; ++i) {
 249                 decl_arg *darg = strct->args->args[i];
 250                 ffi_type *type = malloc(sizeof(*type));
 251                 size_t padding;
 252
 253                 memcpy(type, psi_ffi_decl_arg_type(darg), sizeof(*type));
 254
 255                 ZEND_ASSERT(type->size == darg->layout->len);
 256
 257                 if (type->alignment > maxalign) {
 258                         maxalign = type->alignment;
 259                 }
 260
 261                 if ((padding = psi_offset_padding(darg->layout->pos - offset, type->alignment))) {
 262                         if (nels + padding + 1 > argc) {
 263                                 argc += padding;
 264                                 els = realloc(els, (argc + 1) * sizeof(*els));
 265                                 els[argc] = NULL;
 266                         }
 267                         psi_ffi_struct_type_pad(&els[nels], padding);
 268                         nels += padding;
 269                         offset += padding;
 270                 }
 271                 ZEND_ASSERT(offset == darg->layout->pos);
 272
 273                 offset = (offset + darg->layout->len + type->alignment - 1) & ~(type->alignment - 1);
 274                 els[nels++] = type;
 275         }
 276
 277         /* apply struct alignment padding */
 278         offset = (offset + maxalign - 1) & ~(maxalign - 1);
 279
 280         ZEND_ASSERT(offset <= strct->size);
 281         if (offset < strct->size) {
 282                 psi_ffi_struct_type_pad(&els[nels], strct->size - offset);
 283         }
 284
 285         return els;
 286 }
 287 static inline ffi_type *psi_ffi_decl_type(decl_type *type) {
 288         decl_type *real = real_decl_type(type);
 289
 290         switch (real->type) {
 291         case PSI_T_FUNCTION:
 292                 if (!real->func->call.sym) {
 293                         PSI_LibffiCall *call = PSI_LibffiCallAlloc(&PSI_G(context), real->func);
 294                         ffi_status rc;
 295
 296                         rc = psi_ffi_prep_closure(
 297                                         (void *) &real->func->call.closure.data,
 298                                         &real->func->call.sym, &call->signature, psi_ffi_handler, NULL);
 299                         if (FFI_OK == rc) {
 300                                 real->func->call.info = call;
 301                                 real->func->call.closure.dtor = psi_ffi_closure_free;
 302                         }
 303                 }
 304                 return &ffi_type_pointer;
 305
 306         case PSI_T_STRUCT:
 307                 if (!real->strct->engine.type) {
 308                         ffi_type *strct = calloc(1, sizeof(ffi_type));
 309
 310                         strct->type = FFI_TYPE_STRUCT;
 311                         strct->size = 0;
 312                         strct->elements = psi_ffi_struct_type_elements(real->strct);
 313
 314                         real->strct->engine.type = strct;
 315                         real->strct->engine.dtor = psi_ffi_struct_type_dtor;
 316                 }
 317
 318                 return real->strct->engine.type;
 319
 320         case PSI_T_UNION:
 321                 return psi_ffi_decl_arg_type(real->unn->args->args[0]);
 322
 323         default:
 324                 return psi_ffi_token_type(real->type);
 325         }
 326 }
 327 static inline ffi_type *psi_ffi_decl_arg_type(decl_arg *darg) {
 328         if (darg->var->pointer_level) {
 329                 return &ffi_type_pointer;
 330         } else {
 331                 return psi_ffi_decl_type(darg->type);
 332         }
 333 }
 334
 335
 336 static inline PSI_LibffiContext *PSI_LibffiContextInit(PSI_LibffiContext *L) {
 337         ffi_status rc;
 338
 339         if (!L) {
 340                 L = malloc(sizeof(*L));
 341         }
 342         memset(L, 0, sizeof(*L));
 343
 344         L->params[0] = &ffi_type_pointer;
 345         L->params[1] = &ffi_type_pointer;
 346         rc = ffi_prep_cif(&L->signature, FFI_DEFAULT_ABI, 2, &ffi_type_void, L->params);
 347         ZEND_ASSERT(rc == FFI_OK);
 348
 349         return L;
 350 }
 351
 352 static void psi_ffi_init(PSI_Context *C)
 353 {
 354         C->context = PSI_LibffiContextInit(NULL);
 355 }
 356
 357 static void psi_ffi_dtor(PSI_Context *C)
 358 {
 359         if (C->decls) {
 360                 size_t i;
 361
 362                 for (i = 0; i < C->decls->count; ++i) {
 363                         decl *decl = C->decls->list[i];
 364
 365                         if (decl->call.info) {
 366                                 PSI_LibffiCallFree(decl->call.info);
 367                         }
 368                 }
 369         }
 370         free(C->context);
 371 }
 372
 373 static zend_function_entry *psi_ffi_compile(PSI_Context *C)
 374 {
 375         size_t i, j = 0;
 376         zend_function_entry *zfe;
 377
 378         if (!C->impls) {
 379                 return NULL;
 380         }
 381
 382         zfe = calloc(C->impls->count + 1, sizeof(*zfe));
 383         for (i = 0; i < C->impls->count; ++i) {
 384                 zend_function_entry *zf = &zfe[j];
 385                 PSI_LibffiCall *call;
 386                 impl *impl = C->impls->list[i];
 387
 388                 if (!impl->decl) {
 389                         continue;
 390                 }
 391
 392                 call = PSI_LibffiCallAlloc(C, impl->decl);
 393                 PSI_LibffiCallInitClosure(C, call, impl);
 394
 395                 zf->fname = impl->func->name + (impl->func->name[0] == '\\');
 396                 zf->num_args = impl->func->args->count;
 397                 zf->handler = call->code;
 398                 zf->arg_info = psi_internal_arginfo(impl);
 399                 ++j;
 400         }
 401
 402         for (i = 0; i < C->decls->count; ++i) {
 403                 decl *decl = C->decls->list[i];
 404
 405                 if (decl->impl) {
 406                         continue;
 407                 }
 408
 409                 PSI_LibffiCallAlloc(C, decl);
 410         }
 411
 412         return zfe;
 413 }
 414
 415 static void psi_ffi_call(PSI_Context *C, decl_callinfo *decl_call, impl_vararg *va) {
 416         PSI_LibffiCall *call = decl_call->info;
 417
 418         if (va) {
 419                 ffi_status rc;
 420                 ffi_cif signature;
 421                 size_t i, nfixedargs = decl_call->argc, ntotalargs = nfixedargs + va->args->count;
 422                 void **params = calloc(2 * ntotalargs + 2, sizeof(void *));
 423
 424                 for (i = 0; i < nfixedargs; ++i) {
 425                         params[i] = call->params[i];
 426                         params[i + ntotalargs + 1] = call->params[i + nfixedargs + 1];
 427                 }
 428                 for (i = 0; i < va->args->count; ++i) {
 429                         params[nfixedargs + i] = psi_ffi_impl_type(va->types[i]);
 430                         params[nfixedargs + i + ntotalargs + 1] = &va->values[i];
 431                 }
 432 #ifdef PSI_HAVE_FFI_PREP_CIF_VAR
 433                 rc = ffi_prep_cif_var(&signature, call->signature.abi,
 434                                 nfixedargs, ntotalargs,
 435                                 call->signature.rtype, (ffi_type **) params);
 436 #else
 437                 /* FIXME: test in config.m4; assume we can just call anyway */
 438                 rc = ffi_prep_cif(&signature, call->signature.abi, ntotalargs,
 439                                 call->signature.rtype, (ffi_type **) params);
 440 #endif
 441                 ZEND_ASSERT(FFI_OK == rc);
 442                 ffi_call(&signature, FFI_FN(decl_call->sym), *decl_call->rval, &params[ntotalargs + 1]);
 443                 free(params);
 444         } else {
 445                 ffi_call(&call->signature, FFI_FN(decl_call->sym), *decl_call->rval, decl_call->args);
 446         }
 447 }
 448
 449 static PSI_ContextOps ops = {
 450         psi_ffi_init,
 451         psi_ffi_dtor,
 452         psi_ffi_compile,
 453         psi_ffi_call,
 454 };
 455
 456 PSI_ContextOps *PSI_Libffi(void)
 457 {
 458         return &ops;
 459 }
 460
 461 #endif /* HAVE_LIBFFI */