src/shims/posix/foreign_items.rs

   1 use log::trace;
   2
   3 use rustc_middle::mir;
   4 use rustc_target::abi::{Align, LayoutOf, Size};
   5
   6 use crate::*;
   7 use helpers::check_arg_count;
   8 use shims::posix::fs::EvalContextExt as _;
   9 use shims::posix::sync::EvalContextExt as _;
  10 use shims::posix::thread::EvalContextExt as _;
  11
  12 impl<'mir, 'tcx: 'mir> EvalContextExt<'mir, 'tcx> for crate::MiriEvalContext<'mir, 'tcx> {}
  13 pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx> {
  14     fn emulate_foreign_item_by_name(
  15         &mut self,
  16         link_name: &str,
  17         args: &[OpTy<'tcx, Tag>],
  18         dest: PlaceTy<'tcx, Tag>,
  19         ret: mir::BasicBlock,
  20     ) -> InterpResult<'tcx, bool> {
  21         let this = self.eval_context_mut();
  22
  23         match link_name {
  24             // Environment related shims
  25             "getenv" => {
  26                 let &[name] = check_arg_count(args)?;
  27                 let result = this.getenv(name)?;
  28                 this.write_scalar(result, dest)?;
  29             }
  30             "unsetenv" => {
  31                 let &[name] = check_arg_count(args)?;
  32                 let result = this.unsetenv(name)?;
  33                 this.write_scalar(Scalar::from_i32(result), dest)?;
  34             }
  35             "setenv" => {
  36                 let &[name, value, overwrite] = check_arg_count(args)?;
  37                 this.read_scalar(overwrite)?.to_i32()?;
  38                 let result = this.setenv(name, value)?;
  39                 this.write_scalar(Scalar::from_i32(result), dest)?;
  40             }
  41             "getcwd" => {
  42                 let &[buf, size] = check_arg_count(args)?;
  43                 let result = this.getcwd(buf, size)?;
  44                 this.write_scalar(result, dest)?;
  45             }
  46             "chdir" => {
  47                 let &[path] = check_arg_count(args)?;
  48                 let result = this.chdir(path)?;
  49                 this.write_scalar(Scalar::from_i32(result), dest)?;
  50             }
  51
  52             // File related shims
  53             "open" | "open64" => {
  54                 let &[path, flag, mode] = check_arg_count(args)?;
  55                 let result = this.open(path, flag, mode)?;
  56                 this.write_scalar(Scalar::from_i32(result), dest)?;
  57             }
  58             "fcntl" => {
  59                 let result = this.fcntl(args)?;
  60                 this.write_scalar(Scalar::from_i32(result), dest)?;
  61             }
  62             "read" => {
  63                 let &[fd, buf, count] = check_arg_count(args)?;
  64                 let fd = this.read_scalar(fd)?.to_i32()?;
  65                 let buf = this.read_scalar(buf)?.check_init()?;
  66                 let count = this.read_scalar(count)?.to_machine_usize(this)?;
  67                 let result = this.read(fd, buf, count)?;
  68                 this.write_scalar(Scalar::from_machine_isize(result, this), dest)?;
  69             }
  70             "write" => {
  71                 let &[fd, buf, n] = check_arg_count(args)?;
  72                 let fd = this.read_scalar(fd)?.to_i32()?;
  73                 let buf = this.read_scalar(buf)?.check_init()?;
  74                 let count = this.read_scalar(n)?.to_machine_usize(this)?;
  75                 trace!("Called write({:?}, {:?}, {:?})", fd, buf, count);
  76                 let result = this.write(fd, buf, count)?;
  77                 // Now, `result` is the value we return back to the program.
  78                 this.write_scalar(Scalar::from_machine_isize(result, this), dest)?;
  79             }
  80             "unlink" => {
  81                 let &[path] = check_arg_count(args)?;
  82                 let result = this.unlink(path)?;
  83                 this.write_scalar(Scalar::from_i32(result), dest)?;
  84             }
  85             "symlink" => {
  86                 let &[target, linkpath] = check_arg_count(args)?;
  87                 let result = this.symlink(target, linkpath)?;
  88                 this.write_scalar(Scalar::from_i32(result), dest)?;
  89             }
  90             "rename" => {
  91                 let &[oldpath, newpath] = check_arg_count(args)?;
  92                 let result = this.rename(oldpath, newpath)?;
  93                 this.write_scalar(Scalar::from_i32(result), dest)?;
  94             }
  95             "mkdir" => {
  96                 let &[path, mode] = check_arg_count(args)?;
  97                 let result = this.mkdir(path, mode)?;
  98                 this.write_scalar(Scalar::from_i32(result), dest)?;
  99             }
 100             "rmdir" => {
 101                 let &[path] = check_arg_count(args)?;
 102                 let result = this.rmdir(path)?;
 103                 this.write_scalar(Scalar::from_i32(result), dest)?;
 104             }
 105             "closedir" => {
 106                 let &[dirp] = check_arg_count(args)?;
 107                 let result = this.closedir(dirp)?;
 108                 this.write_scalar(Scalar::from_i32(result), dest)?;
 109             }
 110             "lseek" | "lseek64" => {
 111                 let &[fd, offset, whence] = check_arg_count(args)?;
 112                 let result = this.lseek64(fd, offset, whence)?;
 113                 // "lseek" is only used on macOS which is 64bit-only, so `i64` always works.
 114                 this.write_scalar(Scalar::from_i64(result), dest)?;
 115             }
 116             "fsync" => {
 117                 let &[fd] = check_arg_count(args)?;
 118                 let result = this.fsync(fd)?;
 119                 this.write_scalar(Scalar::from_i32(result), dest)?;
 120             }
 121             "fdatasync" => {
 122                 let &[fd] = check_arg_count(args)?;
 123                 let result = this.fdatasync(fd)?;
 124                 this.write_scalar(Scalar::from_i32(result), dest)?;
 125             }
 126
 127             // Allocation
 128             "posix_memalign" => {
 129                 let &[ret, align, size] = check_arg_count(args)?;
 130                 let ret = this.deref_operand(ret)?;
 131                 let align = this.read_scalar(align)?.to_machine_usize(this)?;
 132                 let size = this.read_scalar(size)?.to_machine_usize(this)?;
 133                 // Align must be power of 2, and also at least ptr-sized (POSIX rules).
 134                 if !align.is_power_of_two() {
 135                     throw_ub_format!("posix_memalign: alignment must be a power of two, but is {}", align);
 136                 }
 137                 if align < this.pointer_size().bytes() {
 138                     throw_ub_format!(
 139                         "posix_memalign: alignment must be at least the size of a pointer, but is {}",
 140                         align,
 141                     );
 142                 }
 143
 144                 if size == 0 {
 145                     this.write_null(ret.into())?;
 146                 } else {
 147                     let ptr = this.memory.allocate(
 148                         Size::from_bytes(size),
 149                         Align::from_bytes(align).unwrap(),
 150                         MiriMemoryKind::C.into(),
 151                     );
 152                     this.write_scalar(ptr, ret.into())?;
 153                 }
 154                 this.write_null(dest)?;
 155             }
 156
 157             // Dynamic symbol loading
 158             "dlsym" => {
 159                 let &[handle, symbol] = check_arg_count(args)?;
 160                 this.read_scalar(handle)?.to_machine_usize(this)?;
 161                 let symbol = this.read_scalar(symbol)?.check_init()?;
 162                 let symbol_name = this.memory.read_c_str(symbol)?;
 163                 if let Some(dlsym) = Dlsym::from_str(symbol_name, &this.tcx.sess.target.target.target_os)? {
 164                     let ptr = this.memory.create_fn_alloc(FnVal::Other(dlsym));
 165                     this.write_scalar(Scalar::from(ptr), dest)?;
 166                 } else {
 167                     this.write_null(dest)?;
 168                 }
 169             }
 170
 171             // Querying system information
 172             "sysconf" => {
 173                 let &[name] = check_arg_count(args)?;
 174                 let name = this.read_scalar(name)?.to_i32()?;
 175
 176                 let sysconfs = &[
 177                     ("_SC_PAGESIZE", Scalar::from_int(PAGE_SIZE, this.pointer_size())),
 178                     ("_SC_NPROCESSORS_ONLN", Scalar::from_int(NUM_CPUS, this.pointer_size())),
 179                 ];
 180                 let mut result = None;
 181                 for &(sysconf_name, value) in sysconfs {
 182                     let sysconf_name = this.eval_libc_i32(sysconf_name)?;
 183                     if sysconf_name == name {
 184                         result = Some(value);
 185                         break;
 186                     }
 187                 }
 188                 if let Some(result) = result {
 189                     this.write_scalar(result, dest)?;
 190                 } else {
 191                     throw_unsup_format!("unimplemented sysconf name: {}", name)
 192                 }
 193             }
 194
 195             // Thread-local storage
 196             "pthread_key_create" => {
 197                 let &[key, dtor] = check_arg_count(args)?;
 198                 let key_place = this.deref_operand(key)?;
 199                 let dtor = this.read_scalar(dtor)?.check_init()?;
 200
 201                 // Extract the function type out of the signature (that seems easier than constructing it ourselves).
 202                 let dtor = match this.test_null(dtor)? {
 203                     Some(dtor_ptr) => Some(this.memory.get_fn(dtor_ptr)?.as_instance()?),
 204                     None => None,
 205                 };
 206
 207                 // Figure out how large a pthread TLS key actually is.
 208                 // To this end, deref the argument type. This is `libc::pthread_key_t`.
 209                 let key_type = key.layout.ty
 210                     .builtin_deref(true)
 211                     .ok_or_else(|| err_ub_format!(
 212                         "wrong signature used for `pthread_key_create`: first argument must be a raw pointer."
 213                     ))?
 214                     .ty;
 215                 let key_layout = this.layout_of(key_type)?;
 216
 217                 // Create key and write it into the memory where `key_ptr` wants it.
 218                 let key = this.machine.tls.create_tls_key(dtor, key_layout.size)?;
 219                 this.write_scalar(Scalar::from_uint(key, key_layout.size), key_place.into())?;
 220
 221                 // Return success (`0`).
 222                 this.write_null(dest)?;
 223             }
 224             "pthread_key_delete" => {
 225                 let &[key] = check_arg_count(args)?;
 226                 let key = this.force_bits(this.read_scalar(key)?.check_init()?, key.layout.size)?;
 227                 this.machine.tls.delete_tls_key(key)?;
 228                 // Return success (0)
 229                 this.write_null(dest)?;
 230             }
 231             "pthread_getspecific" => {
 232                 let &[key] = check_arg_count(args)?;
 233                 let key = this.force_bits(this.read_scalar(key)?.check_init()?, key.layout.size)?;
 234                 let active_thread = this.get_active_thread();
 235                 let ptr = this.machine.tls.load_tls(key, active_thread, this)?;
 236                 this.write_scalar(ptr, dest)?;
 237             }
 238             "pthread_setspecific" => {
 239                 let &[key, new_ptr] = check_arg_count(args)?;
 240                 let key = this.force_bits(this.read_scalar(key)?.check_init()?, key.layout.size)?;
 241                 let active_thread = this.get_active_thread();
 242                 let new_ptr = this.read_scalar(new_ptr)?.check_init()?;
 243                 this.machine.tls.store_tls(key, active_thread, this.test_null(new_ptr)?)?;
 244
 245                 // Return success (`0`).
 246                 this.write_null(dest)?;
 247             }
 248
 249             // Synchronization primitives
 250             "pthread_mutexattr_init" => {
 251                 let &[attr] = check_arg_count(args)?;
 252                 let result = this.pthread_mutexattr_init(attr)?;
 253                 this.write_scalar(Scalar::from_i32(result), dest)?;
 254             }
 255             "pthread_mutexattr_settype" => {
 256                 let &[attr, kind] = check_arg_count(args)?;
 257                 let result = this.pthread_mutexattr_settype(attr, kind)?;
 258                 this.write_scalar(Scalar::from_i32(result), dest)?;
 259             }
 260             "pthread_mutexattr_destroy" => {
 261                 let &[attr] = check_arg_count(args)?;
 262                 let result = this.pthread_mutexattr_destroy(attr)?;
 263                 this.write_scalar(Scalar::from_i32(result), dest)?;
 264             }
 265             "pthread_mutex_init" => {
 266                 let &[mutex, attr] = check_arg_count(args)?;
 267                 let result = this.pthread_mutex_init(mutex, attr)?;
 268                 this.write_scalar(Scalar::from_i32(result), dest)?;
 269             }
 270             "pthread_mutex_lock" => {
 271                 let &[mutex] = check_arg_count(args)?;
 272                 let result = this.pthread_mutex_lock(mutex)?;
 273                 this.write_scalar(Scalar::from_i32(result), dest)?;
 274             }
 275             "pthread_mutex_trylock" => {
 276                 let &[mutex] = check_arg_count(args)?;
 277                 let result = this.pthread_mutex_trylock(mutex)?;
 278                 this.write_scalar(Scalar::from_i32(result), dest)?;
 279             }
 280             "pthread_mutex_unlock" => {
 281                 let &[mutex] = check_arg_count(args)?;
 282                 let result = this.pthread_mutex_unlock(mutex)?;
 283                 this.write_scalar(Scalar::from_i32(result), dest)?;
 284             }
 285             "pthread_mutex_destroy" => {
 286                 let &[mutex] = check_arg_count(args)?;
 287                 let result = this.pthread_mutex_destroy(mutex)?;
 288                 this.write_scalar(Scalar::from_i32(result), dest)?;
 289             }
 290             "pthread_rwlock_rdlock" => {
 291                 let &[rwlock] = check_arg_count(args)?;
 292                 let result = this.pthread_rwlock_rdlock(rwlock)?;
 293                 this.write_scalar(Scalar::from_i32(result), dest)?;
 294             }
 295             "pthread_rwlock_tryrdlock" => {
 296                 let &[rwlock] = check_arg_count(args)?;
 297                 let result = this.pthread_rwlock_tryrdlock(rwlock)?;
 298                 this.write_scalar(Scalar::from_i32(result), dest)?;
 299             }
 300             "pthread_rwlock_wrlock" => {
 301                 let &[rwlock] = check_arg_count(args)?;
 302                 let result = this.pthread_rwlock_wrlock(rwlock)?;
 303                 this.write_scalar(Scalar::from_i32(result), dest)?;
 304             }
 305             "pthread_rwlock_trywrlock" => {
 306                 let &[rwlock] = check_arg_count(args)?;
 307                 let result = this.pthread_rwlock_trywrlock(rwlock)?;
 308                 this.write_scalar(Scalar::from_i32(result), dest)?;
 309             }
 310             "pthread_rwlock_unlock" => {
 311                 let &[rwlock] = check_arg_count(args)?;
 312                 let result = this.pthread_rwlock_unlock(rwlock)?;
 313                 this.write_scalar(Scalar::from_i32(result), dest)?;
 314             }
 315             "pthread_rwlock_destroy" => {
 316                 let &[rwlock] = check_arg_count(args)?;
 317                 let result = this.pthread_rwlock_destroy(rwlock)?;
 318                 this.write_scalar(Scalar::from_i32(result), dest)?;
 319             }
 320             "pthread_condattr_init" => {
 321                 let &[attr] = check_arg_count(args)?;
 322                 let result = this.pthread_condattr_init(attr)?;
 323                 this.write_scalar(Scalar::from_i32(result), dest)?;
 324             }
 325             "pthread_condattr_destroy" => {
 326                 let &[attr] = check_arg_count(args)?;
 327                 let result = this.pthread_condattr_destroy(attr)?;
 328                 this.write_scalar(Scalar::from_i32(result), dest)?;
 329             }
 330             "pthread_cond_init" => {
 331                 let &[cond, attr] = check_arg_count(args)?;
 332                 let result = this.pthread_cond_init(cond, attr)?;
 333                 this.write_scalar(Scalar::from_i32(result), dest)?;
 334             }
 335             "pthread_cond_signal" => {
 336                 let &[cond] = check_arg_count(args)?;
 337                 let result = this.pthread_cond_signal(cond)?;
 338                 this.write_scalar(Scalar::from_i32(result), dest)?;
 339             }
 340             "pthread_cond_broadcast" => {
 341                 let &[cond] = check_arg_count(args)?;
 342                 let result = this.pthread_cond_broadcast(cond)?;
 343                 this.write_scalar(Scalar::from_i32(result), dest)?;
 344             }
 345             "pthread_cond_wait" => {
 346                 let &[cond, mutex] = check_arg_count(args)?;
 347                 let result = this.pthread_cond_wait(cond, mutex)?;
 348                 this.write_scalar(Scalar::from_i32(result), dest)?;
 349             }
 350             "pthread_cond_timedwait" => {
 351                 let &[cond, mutex, abstime] = check_arg_count(args)?;
 352                 this.pthread_cond_timedwait(cond, mutex, abstime, dest)?;
 353             }
 354             "pthread_cond_destroy" => {
 355                 let &[cond] = check_arg_count(args)?;
 356                 let result = this.pthread_cond_destroy(cond)?;
 357                 this.write_scalar(Scalar::from_i32(result), dest)?;
 358             }
 359
 360             // Threading
 361             "pthread_create" => {
 362                 let &[thread, attr, start, arg] = check_arg_count(args)?;
 363                 let result = this.pthread_create(thread, attr, start, arg)?;
 364                 this.write_scalar(Scalar::from_i32(result), dest)?;
 365             }
 366             "pthread_join" => {
 367                 let &[thread, retval] = check_arg_count(args)?;
 368                 let result = this.pthread_join(thread, retval)?;
 369                 this.write_scalar(Scalar::from_i32(result), dest)?;
 370             }
 371             "pthread_detach" => {
 372                 let &[thread] = check_arg_count(args)?;
 373                 let result = this.pthread_detach(thread)?;
 374                 this.write_scalar(Scalar::from_i32(result), dest)?;
 375             }
 376             "pthread_self" => {
 377                 let &[] = check_arg_count(args)?;
 378                 this.pthread_self(dest)?;
 379             }
 380             "sched_yield" => {
 381                 let &[] = check_arg_count(args)?;
 382                 let result = this.sched_yield()?;
 383                 this.write_scalar(Scalar::from_i32(result), dest)?;
 384             }
 385             "nanosleep" => {
 386                 let &[req, rem] = check_arg_count(args)?;
 387                 let result = this.nanosleep(req, rem)?;
 388                 this.write_scalar(Scalar::from_i32(result), dest)?;
 389             }
 390
 391             // Miscellaneous
 392             "isatty" => {
 393                 let &[fd] = check_arg_count(args)?;
 394                 this.read_scalar(fd)?.to_i32()?;
 395                 // "returns 1 if fd is an open file descriptor referring to a terminal; otherwise 0 is returned, and errno is set to indicate the error"
 396                 // FIXME: we just say nothing is a terminal.
 397                 let enotty = this.eval_libc("ENOTTY")?;
 398                 this.set_last_error(enotty)?;
 399                 this.write_null(dest)?;
 400             }
 401             "pthread_atfork" => {
 402                 let &[prepare, parent, child] = check_arg_count(args)?;
 403                 this.force_bits(this.read_scalar(prepare)?.check_init()?, this.memory.pointer_size())?;
 404                 this.force_bits(this.read_scalar(parent)?.check_init()?, this.memory.pointer_size())?;
 405                 this.force_bits(this.read_scalar(child)?.check_init()?, this.memory.pointer_size())?;
 406                 // We do not support forking, so there is nothing to do here.
 407                 this.write_null(dest)?;
 408             }
 409
 410             // Incomplete shims that we "stub out" just to get pre-main initialization code to work.
 411             // These shims are enabled only when the caller is in the standard library.
 412             "pthread_attr_getguardsize"
 413             if this.frame().instance.to_string().starts_with("std::sys::unix::") => {
 414                 let &[_attr, guard_size] = check_arg_count(args)?;
 415                 let guard_size = this.deref_operand(guard_size)?;
 416                 let guard_size_layout = this.libc_ty_layout("size_t")?;
 417                 this.write_scalar(Scalar::from_uint(crate::PAGE_SIZE, guard_size_layout.size), guard_size.into())?;
 418
 419                 // Return success (`0`).
 420                 this.write_null(dest)?;
 421             }
 422
 423             | "pthread_attr_init"
 424             | "pthread_attr_destroy"
 425             if this.frame().instance.to_string().starts_with("std::sys::unix::") => {
 426                 let &[_] = check_arg_count(args)?;
 427                 this.write_null(dest)?;
 428             }
 429             | "pthread_attr_setstacksize"
 430             if this.frame().instance.to_string().starts_with("std::sys::unix::") => {
 431                 let &[_, _] = check_arg_count(args)?;
 432                 this.write_null(dest)?;
 433             }
 434
 435             | "signal"
 436             | "sigaltstack"
 437             if this.frame().instance.to_string().starts_with("std::sys::unix::") => {
 438                 let &[_, _] = check_arg_count(args)?;
 439                 this.write_null(dest)?;
 440             }
 441             | "sigaction"
 442             | "mprotect"
 443             if this.frame().instance.to_string().starts_with("std::sys::unix::") => {
 444                 let &[_, _, _] = check_arg_count(args)?;
 445                 this.write_null(dest)?;
 446             }
 447
 448             // Platform-specific shims
 449             _ => {
 450                 match this.tcx.sess.target.target.target_os.as_str() {
 451                     "linux" => return shims::posix::linux::foreign_items::EvalContextExt::emulate_foreign_item_by_name(this, link_name, args, dest, ret),
 452                     "macos" => return shims::posix::macos::foreign_items::EvalContextExt::emulate_foreign_item_by_name(this, link_name, args, dest, ret),
 453                     _ => unreachable!(),
 454                 }
 455             }
 456         };
 457
 458         Ok(true)
 459     }
 460 }