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