5 use rustc::ty::layout::{Align, LayoutOf, Size};
7 impl<'mir, 'tcx> EvalContextExt<'mir, 'tcx> for crate::MiriEvalContext<'mir, 'tcx> {}
8 pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx> {
9 fn emulate_foreign_item_by_name(
12 args: &[OpTy<'tcx, Tag>],
13 dest: PlaceTy<'tcx, Tag>,
14 ) -> InterpResult<'tcx> {
15 let this = self.eval_context_mut();
16 let tcx = &{ this.tcx.tcx };
19 // Environment related shims
21 let result = this.getenv(args[0])?;
22 this.write_scalar(result, dest)?;
26 let result = this.unsetenv(args[0])?;
27 this.write_scalar(Scalar::from_int(result, dest.layout.size), dest)?;
31 let result = this.setenv(args[0], args[1])?;
32 this.write_scalar(Scalar::from_int(result, dest.layout.size), dest)?;
36 let result = this.getcwd(args[0], args[1])?;
37 this.write_scalar(result, dest)?;
41 let result = this.chdir(args[0])?;
42 this.write_scalar(Scalar::from_int(result, dest.layout.size), dest)?;
47 let result = this.fcntl(args[0], args[1], args.get(2).cloned())?;
48 this.write_scalar(Scalar::from_int(result, dest.layout.size), dest)?;
52 let result = this.read(args[0], args[1], args[2])?;
53 this.write_scalar(Scalar::from_int(result, dest.layout.size), dest)?;
57 let fd = this.read_scalar(args[0])?.to_i32()?;
58 let buf = this.read_scalar(args[1])?.not_undef()?;
59 let n = this.read_scalar(args[2])?.to_machine_usize(tcx)?;
60 trace!("Called write({:?}, {:?}, {:?})", fd, buf, n);
61 let result = if fd == 1 || fd == 2 {
63 use std::io::{self, Write};
65 let buf_cont = this.memory.read_bytes(buf, Size::from_bytes(n))?;
66 // We need to flush to make sure this actually appears on the screen
67 let res = if fd == 1 {
68 // Stdout is buffered, flush to make sure it appears on the screen.
69 // This is the write() syscall of the interpreted program, we want it
70 // to correspond to a write() syscall on the host -- there is no good
71 // in adding extra buffering here.
72 let res = io::stdout().write(buf_cont);
73 io::stdout().flush().unwrap();
76 // No need to flush, stderr is not buffered.
77 io::stderr().write(buf_cont)
84 this.write(args[0], args[1], args[2])?
86 // Now, `result` is the value we return back to the program.
87 this.write_scalar(Scalar::from_int(result, dest.layout.size), dest)?;
91 let result = this.unlink(args[0])?;
92 this.write_scalar(Scalar::from_int(result, dest.layout.size), dest)?;
96 let result = this.symlink(args[0], args[1])?;
97 this.write_scalar(Scalar::from_int(result, dest.layout.size), dest)?;
100 "posix_memalign" => {
101 let ret = this.deref_operand(args[0])?;
102 let align = this.read_scalar(args[1])?.to_machine_usize(this)?;
103 let size = this.read_scalar(args[2])?.to_machine_usize(this)?;
104 // Align must be power of 2, and also at least ptr-sized (POSIX rules).
105 if !align.is_power_of_two() {
106 throw_unsup!(HeapAllocNonPowerOfTwoAlignment(align));
108 if align < this.pointer_size().bytes() {
110 "posix_memalign: alignment must be at least the size of a pointer, but is {}",
116 this.write_null(ret.into())?;
118 let ptr = this.memory.allocate(
119 Size::from_bytes(size),
120 Align::from_bytes(align).unwrap(),
121 MiriMemoryKind::C.into(),
123 this.write_scalar(ptr, ret.into())?;
125 this.write_null(dest)?;
129 let _handle = this.read_scalar(args[0])?;
130 let symbol = this.read_scalar(args[1])?.not_undef()?;
131 let symbol_name = this.memory.read_c_str(symbol)?;
132 let err = format!("bad c unicode symbol: {:?}", symbol_name);
133 let symbol_name = ::std::str::from_utf8(symbol_name).unwrap_or(&err);
134 if let Some(dlsym) = Dlsym::from_str(symbol_name)? {
135 let ptr = this.memory.create_fn_alloc(FnVal::Other(dlsym));
136 this.write_scalar(Scalar::from(ptr), dest)?;
138 this.write_null(dest)?;
143 let ptr = this.read_scalar(args[0])?.not_undef()?;
144 let val = this.read_scalar(args[1])?.to_i32()? as u8;
145 let num = this.read_scalar(args[2])?.to_machine_usize(this)?;
146 if let Some(idx) = this
148 .read_bytes(ptr, Size::from_bytes(num))?
151 .position(|&c| c == val)
153 let new_ptr = ptr.ptr_offset(Size::from_bytes(num - idx as u64 - 1), this)?;
154 this.write_scalar(new_ptr, dest)?;
156 this.write_null(dest)?;
160 // Hook pthread calls that go to the thread-local storage memory subsystem.
161 "pthread_key_create" => {
162 let key_place = this.deref_operand(args[0])?;
164 // Extract the function type out of the signature (that seems easier than constructing it ourselves).
165 let dtor = match this.test_null(this.read_scalar(args[1])?.not_undef()?)? {
166 Some(dtor_ptr) => Some(this.memory.get_fn(dtor_ptr)?.as_instance()?),
170 // Figure out how large a pthread TLS key actually is.
171 // This is `libc::pthread_key_t`.
172 let key_type = args[0].layout.ty
174 .ok_or_else(|| err_ub_format!(
175 "wrong signature used for `pthread_key_create`: first argument must be a raw pointer."
178 let key_layout = this.layout_of(key_type)?;
180 // Create key and write it into the memory where `key_ptr` wants it.
181 let key = this.machine.tls.create_tls_key(dtor) as u128;
182 if key_layout.size.bits() < 128 && key >= (1u128 << key_layout.size.bits() as u128)
184 throw_unsup!(OutOfTls);
187 this.write_scalar(Scalar::from_uint(key, key_layout.size), key_place.into())?;
189 // Return success (`0`).
190 this.write_null(dest)?;
192 "pthread_key_delete" => {
193 let key = this.read_scalar(args[0])?.to_bits(args[0].layout.size)?;
194 this.machine.tls.delete_tls_key(key)?;
195 // Return success (0)
196 this.write_null(dest)?;
198 "pthread_getspecific" => {
199 let key = this.read_scalar(args[0])?.to_bits(args[0].layout.size)?;
200 let ptr = this.machine.tls.load_tls(key, tcx)?;
201 this.write_scalar(ptr, dest)?;
203 "pthread_setspecific" => {
204 let key = this.read_scalar(args[0])?.to_bits(args[0].layout.size)?;
205 let new_ptr = this.read_scalar(args[1])?.not_undef()?;
206 this.machine.tls.store_tls(key, this.test_null(new_ptr)?)?;
208 // Return success (`0`).
209 this.write_null(dest)?;
212 // Stack size/address stuff.
213 | "pthread_attr_init"
214 | "pthread_attr_destroy"
216 | "pthread_attr_setstacksize" => {
217 this.write_null(dest)?;
219 "pthread_attr_getstack" => {
220 let addr_place = this.deref_operand(args[1])?;
221 let size_place = this.deref_operand(args[2])?;
224 Scalar::from_uint(STACK_ADDR, addr_place.layout.size),
228 Scalar::from_uint(STACK_SIZE, size_place.layout.size),
232 // Return success (`0`).
233 this.write_null(dest)?;
236 // We don't support threading. (Also for Windows.)
240 throw_unsup_format!("Miri does not support threading");
243 // Stub out calls for condvar, mutex and rwlock, to just return `0`.
244 | "pthread_mutexattr_init"
245 | "pthread_mutexattr_settype"
246 | "pthread_mutex_init"
247 | "pthread_mutexattr_destroy"
248 | "pthread_mutex_lock"
249 | "pthread_mutex_unlock"
250 | "pthread_mutex_destroy"
251 | "pthread_rwlock_rdlock"
252 | "pthread_rwlock_unlock"
253 | "pthread_rwlock_wrlock"
254 | "pthread_rwlock_destroy"
255 | "pthread_condattr_init"
256 | "pthread_condattr_setclock"
257 | "pthread_cond_init"
258 | "pthread_condattr_destroy"
259 | "pthread_cond_destroy"
261 this.write_null(dest)?;
264 // We don't support fork so we don't have to do anything for atfork.
265 "pthread_atfork" => {
266 this.write_null(dest)?;
271 match this.tcx.sess.target.target.target_os.to_lowercase().as_str() {
272 "linux" => linux::EvalContextExt::emulate_foreign_item_by_name(this, link_name, args, dest)?,
273 "macos" => macos::EvalContextExt::emulate_foreign_item_by_name(this, link_name, args, dest)?,
283 // Shims the posix 'getrandom()' syscall.
285 this: &mut MiriEvalContext<'_, 'tcx>,
286 args: &[OpTy<'tcx, Tag>],
287 dest: PlaceTy<'tcx, Tag>,
288 ) -> InterpResult<'tcx> {
289 let ptr = this.read_scalar(args[0])?.not_undef()?;
290 let len = this.read_scalar(args[1])?.to_machine_usize(this)?;
292 // The only supported flags are GRND_RANDOM and GRND_NONBLOCK,
293 // neither of which have any effect on our current PRNG.
294 let _flags = this.read_scalar(args[2])?.to_i32()?;
296 this.gen_random(ptr, len as usize)?;
297 this.write_scalar(Scalar::from_uint(len, dest.layout.size), dest)?;