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