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