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