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