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         decl *decl = _data;
  85         size_t i;
  86
  87         // prepare args for the userland call
  88         for (i = 0; i < decl->args->count; ++i) {
  89
  90         }
  91         // marshal return value of the userland call
  92         switch (decl->func->type->type) {
  93
  94         }
  95 }
  96
  97 static inline ffi_type *psi_ffi_decl_arg_type(decl_arg *darg);
  98
  99 typedef struct PSI_LibffiContext {
 100         ffi_cif signature;
 101         ffi_type *params[2];
 102 } PSI_LibffiContext;
 103
 104 typedef struct PSI_LibffiCall {
 105         void *code;
 106         ffi_closure *closure;
 107         ffi_cif signature;
 108         void *params[1]; /* [type1, type2, NULL, arg1, arg2] ... */
 109 } PSI_LibffiCall;
 110
 111 static inline ffi_abi psi_ffi_abi(const char *convention) {
 112         return FFI_DEFAULT_ABI;
 113 }
 114
 115 static inline PSI_LibffiCall *PSI_LibffiCallAlloc(PSI_Context *C, decl *decl) {
 116         int rc;
 117         size_t i, c = decl->args ? decl->args->count : 0;
 118         PSI_LibffiCall *call = calloc(1, sizeof(*call) + 2 * c * sizeof(void *));
 119
 120         for (i = 0; i < c; ++i) {
 121                 call->params[i] = psi_ffi_decl_arg_type(decl->args->args[i]);
 122         }
 123         call->params[c] = NULL;
 124
 125         decl->call.info = call;
 126         decl->call.rval = &decl->func->ptr;
 127         decl->call.argc = c;
 128         decl->call.args = (void **) &call->params[c+1];
 129
 130         rc = ffi_prep_cif(&call->signature, psi_ffi_abi(decl->abi->convention),
 131                         c, psi_ffi_decl_arg_type(decl->func), (ffi_type **) call->params);
 132         ZEND_ASSERT(FFI_OK == rc);
 133
 134         return call;
 135 }
 136
 137 static inline void PSI_LibffiCallInitClosure(PSI_Context *C, PSI_LibffiCall *call, impl *impl) {
 138         PSI_LibffiContext *context = C->context;
 139         ffi_status rc;
 140
 141         rc = psi_ffi_prep_closure(&call->closure, &call->code, &context->signature, psi_ffi_handler, impl);
 142         ZEND_ASSERT(FFI_OK == rc);
 143 }
 144
 145 static inline void PSI_LibffiCallFree(PSI_LibffiCall *call) {
 146         if (call->closure) {
 147                 psi_ffi_closure_free(call->closure);
 148         }
 149         free(call);
 150 }
 151
 152 static inline ffi_type *psi_ffi_token_type(token_t t) {
 153         switch (t) {
 154         default:
 155                 ZEND_ASSERT(0);
 156                 /* no break */
 157         case PSI_T_VOID:
 158                 return &ffi_type_void;
 159         case PSI_T_INT8:
 160                 return &ffi_type_sint8;
 161         case PSI_T_UINT8:
 162                 return &ffi_type_uint8;
 163         case PSI_T_INT16:
 164                 return &ffi_type_sint16;
 165         case PSI_T_UINT16:
 166                 return &ffi_type_uint16;
 167         case PSI_T_INT32:
 168                 return &ffi_type_sint32;
 169         case PSI_T_UINT32:
 170                 return &ffi_type_uint32;
 171         case PSI_T_INT64:
 172                 return &ffi_type_sint64;
 173         case PSI_T_UINT64:
 174                 return &ffi_type_uint64;
 175         case PSI_T_BOOL:
 176                 return &ffi_type_uchar;
 177         case PSI_T_INT:
 178         case PSI_T_ENUM:
 179                 return &ffi_type_sint;
 180         case PSI_T_LONG:
 181                 return &ffi_type_slong;
 182         case PSI_T_FLOAT:
 183                 return &ffi_type_float;
 184         case PSI_T_DOUBLE:
 185                 return &ffi_type_double;
 186 #ifdef HAVE_LONG_DOUBLE
 187         case PSI_T_LONG_DOUBLE:
 188                 return &ffi_type_longdouble;
 189 #endif
 190         case PSI_T_POINTER:
 191         case PSI_T_FUNCTION:
 192                 return &ffi_type_pointer;
 193         }
 194 }
 195 static inline ffi_type *psi_ffi_impl_type(token_t impl_type) {
 196         switch (impl_type) {
 197         case PSI_T_BOOL:
 198                 return &ffi_type_sint8;
 199         case PSI_T_INT:
 200                 return &ffi_type_sint64;
 201         case PSI_T_STRING:
 202                 return &ffi_type_pointer;
 203         case PSI_T_FLOAT:
 204         case PSI_T_DOUBLE:
 205                 return &ffi_type_double;
 206         EMPTY_SWITCH_DEFAULT_CASE();
 207         }
 208         return NULL;
 209 }
 210 static void psi_ffi_struct_type_dtor(void *type) {
 211         ffi_type *strct = type;
 212
 213         if (strct->elements) {
 214                 ffi_type **ptr;
 215
 216                 for (ptr = strct->elements; *ptr; ++ptr) {
 217                         free(*ptr);
 218                 }
 219                 free(strct->elements);
 220         }
 221         free(strct);
 222 }
 223
 224 static size_t psi_ffi_struct_type_pad(ffi_type **els, size_t padding) {
 225         size_t i;
 226
 227         for (i = 0; i < padding; ++i) {
 228                 ffi_type *pad = malloc(sizeof(*pad));
 229
 230                 memcpy(pad, &ffi_type_schar, sizeof(*pad));
 231                 *els++ = pad;
 232         }
 233
 234         return padding;
 235 }
 236
 237 static ffi_type **psi_ffi_struct_type_elements(decl_struct *strct) {
 238         size_t i, argc = strct->args->count, nels = 0, offset = 0, maxalign = 0;
 239         ffi_type **els = calloc(argc + 1, sizeof(*els));
 240
 241         for (i = 0; i < strct->args->count; ++i) {
 242                 decl_arg *darg = strct->args->args[i];
 243                 ffi_type *type = malloc(sizeof(*type));
 244                 size_t padding;
 245
 246                 memcpy(type, psi_ffi_decl_arg_type(darg), sizeof(*type));
 247
 248                 ZEND_ASSERT(type->size == darg->layout->len);
 249
 250                 if (type->alignment > maxalign) {
 251                         maxalign = type->alignment;
 252                 }
 253
 254                 if ((padding = psi_offset_padding(darg->layout->pos - offset, type->alignment))) {
 255                         if (nels + padding + 1 > argc) {
 256                                 argc += padding;
 257                                 els = realloc(els, (argc + 1) * sizeof(*els));
 258                                 els[argc] = NULL;
 259                         }
 260                         psi_ffi_struct_type_pad(&els[nels], padding);
 261                         nels += padding;
 262                         offset += padding;
 263                 }
 264                 ZEND_ASSERT(offset == darg->layout->pos);
 265
 266                 offset = (offset + darg->layout->len + type->alignment - 1) & ~(type->alignment - 1);
 267                 els[nels++] = type;
 268         }
 269
 270         /* apply struct alignment padding */
 271         offset = (offset + maxalign - 1) & ~(maxalign - 1);
 272
 273         ZEND_ASSERT(offset <= strct->size);
 274         if (offset < strct->size) {
 275                 psi_ffi_struct_type_pad(&els[nels], strct->size - offset);
 276         }
 277
 278         return els;
 279 }
 280 static inline ffi_type *psi_ffi_decl_type(decl_type *type) {
 281         decl_type *real = real_decl_type(type);
 282
 283         switch (real->type) {
 284         case PSI_T_FUNCTION:
 285                 if (!real->func->call.sym) {
 286                         PSI_LibffiCall *call = PSI_LibffiCallAlloc(&PSI_G(context), real->func);
 287                         ffi_status rc;
 288
 289                         rc = psi_ffi_prep_closure(&real->func->call.closure.data, &real->func->call.sym,
 290                                         &call->signature, psi_ffi_handler, NULL);
 291                         if (FFI_OK == rc) {
 292                                 real->func->call.info = call;
 293                                 real->func->call.closure.dtor = psi_ffi_closure_free;
 294                         }
 295                 }
 296                 return &ffi_type_pointer;
 297
 298         case PSI_T_STRUCT:
 299                 if (!real->strct->engine.type) {
 300                         ffi_type *strct = calloc(1, sizeof(ffi_type));
 301
 302                         strct->type = FFI_TYPE_STRUCT;
 303                         strct->size = 0;
 304                         strct->elements = psi_ffi_struct_type_elements(real->strct);
 305
 306                         real->strct->engine.type = strct;
 307                         real->strct->engine.dtor = psi_ffi_struct_type_dtor;
 308                 }
 309
 310                 return real->strct->engine.type;
 311
 312         case PSI_T_UNION:
 313                 return psi_ffi_decl_arg_type(real->unn->args->args[0]);
 314
 315         default:
 316                 return psi_ffi_token_type(real->type);
 317         }
 318 }
 319 static inline ffi_type *psi_ffi_decl_arg_type(decl_arg *darg) {
 320         if (darg->var->pointer_level) {
 321                 return &ffi_type_pointer;
 322         } else {
 323                 return psi_ffi_decl_type(darg->type);
 324         }
 325 }
 326
 327
 328 static inline PSI_LibffiContext *PSI_LibffiContextInit(PSI_LibffiContext *L) {
 329         ffi_status rc;
 330
 331         if (!L) {
 332                 L = malloc(sizeof(*L));
 333         }
 334         memset(L, 0, sizeof(*L));
 335
 336         L->params[0] = &ffi_type_pointer;
 337         L->params[1] = &ffi_type_pointer;
 338         rc = ffi_prep_cif(&L->signature, FFI_DEFAULT_ABI, 2, &ffi_type_void, L->params);
 339         ZEND_ASSERT(rc == FFI_OK);
 340
 341         return L;
 342 }
 343
 344 static void psi_ffi_init(PSI_Context *C)
 345 {
 346         C->context = PSI_LibffiContextInit(NULL);
 347 }
 348
 349 static void psi_ffi_dtor(PSI_Context *C)
 350 {
 351         if (C->decls) {
 352                 size_t i;
 353
 354                 for (i = 0; i < C->decls->count; ++i) {
 355                         decl *decl = C->decls->list[i];
 356
 357                         if (decl->call.info) {
 358                                 PSI_LibffiCallFree(decl->call.info);
 359                         }
 360                 }
 361         }
 362         free(C->context);
 363 }
 364
 365 static zend_function_entry *psi_ffi_compile(PSI_Context *C)
 366 {
 367         size_t i, j = 0;
 368         zend_function_entry *zfe;
 369
 370         if (!C->impls) {
 371                 return NULL;
 372         }
 373
 374         zfe = calloc(C->impls->count + 1, sizeof(*zfe));
 375         for (i = 0; i < C->impls->count; ++i) {
 376                 zend_function_entry *zf = &zfe[j];
 377                 PSI_LibffiCall *call;
 378                 impl *impl = C->impls->list[i];
 379
 380                 if (!impl->decl) {
 381                         continue;
 382                 }
 383
 384                 call = PSI_LibffiCallAlloc(C, impl->decl);
 385                 PSI_LibffiCallInitClosure(C, call, impl);
 386
 387                 zf->fname = impl->func->name + (impl->func->name[0] == '\\');
 388                 zf->num_args = impl->func->args->count;
 389                 zf->handler = call->code;
 390                 zf->arg_info = psi_internal_arginfo(impl);
 391                 ++j;
 392         }
 393
 394         for (i = 0; i < C->decls->count; ++i) {
 395                 decl *decl = C->decls->list[i];
 396
 397                 if (decl->impl) {
 398                         continue;
 399                 }
 400
 401                 PSI_LibffiCallAlloc(C, decl);
 402         }
 403
 404         return zfe;
 405 }
 406
 407 static void psi_ffi_call(PSI_Context *C, decl_callinfo *decl_call, impl_vararg *va) {
 408         PSI_LibffiCall *call = decl_call->info;
 409
 410         if (va) {
 411                 ffi_status rc;
 412                 ffi_cif signature;
 413                 size_t i, nfixedargs = decl_call->argc, ntotalargs = nfixedargs + va->args->count;
 414                 void **params = calloc(2 * ntotalargs + 2, sizeof(void *));
 415
 416                 for (i = 0; i < nfixedargs; ++i) {
 417                         params[i] = call->params[i];
 418                         params[i + ntotalargs + 1] = call->params[i + nfixedargs + 1];
 419                 }
 420                 for (i = 0; i < va->args->count; ++i) {
 421                         params[nfixedargs + i] = psi_ffi_impl_type(va->types[i]);
 422                         params[nfixedargs + i + ntotalargs + 1] = &va->values[i];
 423                 }
 424 #ifdef PSI_HAVE_FFI_PREP_CIF_VAR
 425                 rc = ffi_prep_cif_var(&signature, call->signature.abi,
 426                                 nfixedargs, ntotalargs,
 427                                 call->signature.rtype, (ffi_type **) params);
 428 #else
 429                 /* FIXME: test in config.m4; assume we can just call anyway */
 430                 rc = ffi_prep_cif(&signature, call->signature.abi, ntotalargs,
 431                                 call->signature.rtype, (ffi_type **) params);
 432 #endif
 433                 ZEND_ASSERT(FFI_OK == rc);
 434                 ffi_call(&signature, FFI_FN(decl_call->sym), *decl_call->rval, &params[ntotalargs + 1]);
 435                 free(params);
 436         } else {
 437                 ffi_call(&call->signature, FFI_FN(decl_call->sym), *decl_call->rval, decl_call->args);
 438         }
 439 }
 440
 441 static PSI_ContextOps ops = {
 442         psi_ffi_init,
 443         psi_ffi_dtor,
 444         psi_ffi_compile,
 445         psi_ffi_call,
 446 };
 447
 448 PSI_ContextOps *PSI_Libffi(void)
 449 {
 450         return &ops;
 451 }
 452
 453 #endif /* HAVE_LIBFFI */