miri/shims/unix/macos/
foreign_items.rs

1use rustc_abi::CanonAbi;
2use rustc_middle::ty::Ty;
3use rustc_span::Symbol;
4use rustc_target::callconv::FnAbi;
5
6use super::sync::{EvalContextExt as _, MacOsFutexTimeout};
7use crate::shims::unix::*;
8use crate::*;
9
10pub fn is_dyn_sym(name: &str) -> bool {
11    match name {
12        // These only became available with macOS 11.0, so std looks them up dynamically.
13        "os_sync_wait_on_address"
14        | "os_sync_wait_on_address_with_deadline"
15        | "os_sync_wait_on_address_with_timeout"
16        | "os_sync_wake_by_address_any"
17        | "os_sync_wake_by_address_all" => true,
18        _ => false,
19    }
20}
21
22impl<'tcx> EvalContextExt<'tcx> for crate::MiriInterpCx<'tcx> {}
23pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
24    fn emulate_foreign_item_inner(
25        &mut self,
26        link_name: Symbol,
27        abi: &FnAbi<'tcx, Ty<'tcx>>,
28        args: &[OpTy<'tcx>],
29        dest: &MPlaceTy<'tcx>,
30    ) -> InterpResult<'tcx, EmulateItemResult> {
31        let this = self.eval_context_mut();
32
33        // See `fn emulate_foreign_item_inner` in `shims/foreign_items.rs` for the general pattern.
34
35        match link_name.as_str() {
36            // errno
37            "__error" => {
38                let [] = this.check_shim(abi, CanonAbi::C, link_name, args)?;
39                let errno_place = this.last_error_place()?;
40                this.write_scalar(errno_place.to_ref(this).to_scalar(), dest)?;
41            }
42
43            // File related shims
44            "close$NOCANCEL" => {
45                let [result] = this.check_shim(abi, CanonAbi::C, link_name, args)?;
46                let result = this.close(result)?;
47                this.write_scalar(result, dest)?;
48            }
49            "stat" | "stat64" | "stat$INODE64" => {
50                let [path, buf] = this.check_shim(abi, CanonAbi::C, link_name, args)?;
51                let result = this.macos_fbsd_solarish_stat(path, buf)?;
52                this.write_scalar(result, dest)?;
53            }
54            "lstat" | "lstat64" | "lstat$INODE64" => {
55                let [path, buf] = this.check_shim(abi, CanonAbi::C, link_name, args)?;
56                let result = this.macos_fbsd_solarish_lstat(path, buf)?;
57                this.write_scalar(result, dest)?;
58            }
59            "fstat" | "fstat64" | "fstat$INODE64" => {
60                let [fd, buf] = this.check_shim(abi, CanonAbi::C, link_name, args)?;
61                let result = this.macos_fbsd_solarish_fstat(fd, buf)?;
62                this.write_scalar(result, dest)?;
63            }
64            "opendir$INODE64" => {
65                let [name] = this.check_shim(abi, CanonAbi::C, link_name, args)?;
66                let result = this.opendir(name)?;
67                this.write_scalar(result, dest)?;
68            }
69            "readdir_r" | "readdir_r$INODE64" => {
70                let [dirp, entry, result] = this.check_shim(abi, CanonAbi::C, link_name, args)?;
71                let result = this.macos_fbsd_readdir_r(dirp, entry, result)?;
72                this.write_scalar(result, dest)?;
73            }
74            "realpath$DARWIN_EXTSN" => {
75                let [path, resolved_path] = this.check_shim(abi, CanonAbi::C, link_name, args)?;
76                let result = this.realpath(path, resolved_path)?;
77                this.write_scalar(result, dest)?;
78            }
79            "ioctl" => {
80                let ([fd_num, cmd], varargs) =
81                    this.check_shim_variadic(abi, CanonAbi::C, link_name, args)?;
82                let result = this.ioctl(fd_num, cmd, varargs)?;
83                this.write_scalar(result, dest)?;
84            }
85
86            // Environment related shims
87            "_NSGetEnviron" => {
88                let [] = this.check_shim(abi, CanonAbi::C, link_name, args)?;
89                let environ = this.machine.env_vars.unix().environ();
90                this.write_pointer(environ, dest)?;
91            }
92
93            // Random data generation
94            "CCRandomGenerateBytes" => {
95                let [bytes, count] = this.check_shim(abi, CanonAbi::C, link_name, args)?;
96                let bytes = this.read_pointer(bytes)?;
97                let count = this.read_target_usize(count)?;
98                let success = this.eval_libc_i32("kCCSuccess");
99                this.gen_random(bytes, count)?;
100                this.write_int(success, dest)?;
101            }
102
103            // Time related shims
104            "mach_absolute_time" => {
105                let [] = this.check_shim(abi, CanonAbi::C, link_name, args)?;
106                let result = this.mach_absolute_time()?;
107                this.write_scalar(result, dest)?;
108            }
109
110            "mach_timebase_info" => {
111                let [info] = this.check_shim(abi, CanonAbi::C, link_name, args)?;
112                let result = this.mach_timebase_info(info)?;
113                this.write_scalar(result, dest)?;
114            }
115
116            // Access to command-line arguments
117            "_NSGetArgc" => {
118                let [] = this.check_shim(abi, CanonAbi::C, link_name, args)?;
119                this.write_pointer(this.machine.argc.expect("machine must be initialized"), dest)?;
120            }
121            "_NSGetArgv" => {
122                let [] = this.check_shim(abi, CanonAbi::C, link_name, args)?;
123                this.write_pointer(this.machine.argv.expect("machine must be initialized"), dest)?;
124            }
125            "_NSGetExecutablePath" => {
126                let [buf, bufsize] = this.check_shim(abi, CanonAbi::C, link_name, args)?;
127                this.check_no_isolation("`_NSGetExecutablePath`")?;
128
129                let buf_ptr = this.read_pointer(buf)?;
130                let bufsize = this.deref_pointer_as(bufsize, this.machine.layouts.u32)?;
131
132                // Using the host current_exe is a bit off, but consistent with Linux
133                // (where stdlib reads /proc/self/exe).
134                let path = std::env::current_exe().unwrap();
135                let (written, size_needed) = this.write_path_to_c_str(
136                    &path,
137                    buf_ptr,
138                    this.read_scalar(&bufsize)?.to_u32()?.into(),
139                )?;
140
141                if written {
142                    this.write_null(dest)?;
143                } else {
144                    this.write_scalar(Scalar::from_u32(size_needed.try_into().unwrap()), &bufsize)?;
145                    this.write_int(-1, dest)?;
146                }
147            }
148
149            // Thread-local storage
150            "_tlv_atexit" => {
151                let [dtor, data] = this.check_shim(abi, CanonAbi::C, link_name, args)?;
152                let dtor = this.read_pointer(dtor)?;
153                let dtor = this.get_ptr_fn(dtor)?.as_instance()?;
154                let data = this.read_scalar(data)?;
155                let active_thread = this.active_thread();
156                this.machine.tls.add_macos_thread_dtor(active_thread, dtor, data)?;
157            }
158
159            // Querying system information
160            "pthread_get_stackaddr_np" => {
161                let [thread] = this.check_shim(abi, CanonAbi::C, link_name, args)?;
162                this.read_target_usize(thread)?;
163                let stack_addr = Scalar::from_uint(this.machine.stack_addr, this.pointer_size());
164                this.write_scalar(stack_addr, dest)?;
165            }
166            "pthread_get_stacksize_np" => {
167                let [thread] = this.check_shim(abi, CanonAbi::C, link_name, args)?;
168                this.read_target_usize(thread)?;
169                let stack_size = Scalar::from_uint(this.machine.stack_size, this.pointer_size());
170                this.write_scalar(stack_size, dest)?;
171            }
172
173            // Threading
174            "pthread_setname_np" => {
175                let [name] = this.check_shim(abi, CanonAbi::C, link_name, args)?;
176
177                // The real implementation has logic in two places:
178                // * in userland at https://github.com/apple-oss-distributions/libpthread/blob/c032e0b076700a0a47db75528a282b8d3a06531a/src/pthread.c#L1178-L1200,
179                // * in kernel at https://github.com/apple-oss-distributions/xnu/blob/8d741a5de7ff4191bf97d57b9f54c2f6d4a15585/bsd/kern/proc_info.c#L3218-L3227.
180                //
181                // The function in libc calls the kernel to validate
182                // the security policies and the input. If all of the requirements
183                // are met, then the name is set and 0 is returned. Otherwise, if
184                // the specified name is lomnger than MAXTHREADNAMESIZE, then
185                // ENAMETOOLONG is returned.
186                let thread = this.pthread_self()?;
187                let res = match this.pthread_setname_np(
188                    thread,
189                    this.read_scalar(name)?,
190                    this.eval_libc("MAXTHREADNAMESIZE").to_target_usize(this)?,
191                    /* truncate */ false,
192                )? {
193                    ThreadNameResult::Ok => Scalar::from_u32(0),
194                    ThreadNameResult::NameTooLong => this.eval_libc("ENAMETOOLONG"),
195                    ThreadNameResult::ThreadNotFound => unreachable!(),
196                };
197                // Contrary to the manpage, `pthread_setname_np` on macOS still
198                // returns an integer indicating success.
199                this.write_scalar(res, dest)?;
200            }
201            "pthread_getname_np" => {
202                let [thread, name, len] = this.check_shim(abi, CanonAbi::C, link_name, args)?;
203
204                // The function's behavior isn't portable between platforms.
205                // In case of macOS, a truncated name (due to a too small buffer)
206                // does not lead to an error.
207                //
208                // For details, see the implementation at
209                // https://github.com/apple-oss-distributions/libpthread/blob/c032e0b076700a0a47db75528a282b8d3a06531a/src/pthread.c#L1160-L1175.
210                // The key part is the strlcpy, which truncates the resulting value,
211                // but always null terminates (except for zero sized buffers).
212                let res = match this.pthread_getname_np(
213                    this.read_scalar(thread)?,
214                    this.read_scalar(name)?,
215                    this.read_scalar(len)?,
216                    /* truncate */ true,
217                )? {
218                    ThreadNameResult::Ok => Scalar::from_u32(0),
219                    // `NameTooLong` is possible when the buffer is zero sized,
220                    ThreadNameResult::NameTooLong => Scalar::from_u32(0),
221                    ThreadNameResult::ThreadNotFound => this.eval_libc("ESRCH"),
222                };
223                this.write_scalar(res, dest)?;
224            }
225
226            // Synchronization primitives
227            "os_sync_wait_on_address" => {
228                let [addr_op, value_op, size_op, flags_op] =
229                    this.check_shim(abi, CanonAbi::C, link_name, args)?;
230                this.os_sync_wait_on_address(
231                    addr_op,
232                    value_op,
233                    size_op,
234                    flags_op,
235                    MacOsFutexTimeout::None,
236                    dest,
237                )?;
238            }
239            "os_sync_wait_on_address_with_deadline" => {
240                let [addr_op, value_op, size_op, flags_op, clock_op, timeout_op] =
241                    this.check_shim(abi, CanonAbi::C, link_name, args)?;
242                this.os_sync_wait_on_address(
243                    addr_op,
244                    value_op,
245                    size_op,
246                    flags_op,
247                    MacOsFutexTimeout::Absolute { clock_op, timeout_op },
248                    dest,
249                )?;
250            }
251            "os_sync_wait_on_address_with_timeout" => {
252                let [addr_op, value_op, size_op, flags_op, clock_op, timeout_op] =
253                    this.check_shim(abi, CanonAbi::C, link_name, args)?;
254                this.os_sync_wait_on_address(
255                    addr_op,
256                    value_op,
257                    size_op,
258                    flags_op,
259                    MacOsFutexTimeout::Relative { clock_op, timeout_op },
260                    dest,
261                )?;
262            }
263            "os_sync_wake_by_address_any" => {
264                let [addr_op, size_op, flags_op] =
265                    this.check_shim(abi, CanonAbi::C, link_name, args)?;
266                this.os_sync_wake_by_address(
267                    addr_op, size_op, flags_op, /* all */ false, dest,
268                )?;
269            }
270            "os_sync_wake_by_address_all" => {
271                let [addr_op, size_op, flags_op] =
272                    this.check_shim(abi, CanonAbi::C, link_name, args)?;
273                this.os_sync_wake_by_address(
274                    addr_op, size_op, flags_op, /* all */ true, dest,
275                )?;
276            }
277            "os_unfair_lock_lock" => {
278                let [lock_op] = this.check_shim(abi, CanonAbi::C, link_name, args)?;
279                this.os_unfair_lock_lock(lock_op)?;
280            }
281            "os_unfair_lock_trylock" => {
282                let [lock_op] = this.check_shim(abi, CanonAbi::C, link_name, args)?;
283                this.os_unfair_lock_trylock(lock_op, dest)?;
284            }
285            "os_unfair_lock_unlock" => {
286                let [lock_op] = this.check_shim(abi, CanonAbi::C, link_name, args)?;
287                this.os_unfair_lock_unlock(lock_op)?;
288            }
289            "os_unfair_lock_assert_owner" => {
290                let [lock_op] = this.check_shim(abi, CanonAbi::C, link_name, args)?;
291                this.os_unfair_lock_assert_owner(lock_op)?;
292            }
293            "os_unfair_lock_assert_not_owner" => {
294                let [lock_op] = this.check_shim(abi, CanonAbi::C, link_name, args)?;
295                this.os_unfair_lock_assert_not_owner(lock_op)?;
296            }
297
298            _ => return interp_ok(EmulateItemResult::NotSupported),
299        };
300
301        interp_ok(EmulateItemResult::NeedsReturn)
302    }
303
304    fn ioctl(
305        &mut self,
306        fd_num: &OpTy<'tcx>,
307        cmd: &OpTy<'tcx>,
308        _varargs: &[OpTy<'tcx>],
309    ) -> InterpResult<'tcx, Scalar> {
310        let this = self.eval_context_mut();
311
312        let fioclex = this.eval_libc_u64("FIOCLEX");
313
314        let fd_num = this.read_scalar(fd_num)?.to_i32()?;
315        let cmd = this.read_scalar(cmd)?.to_u64()?;
316
317        if cmd == fioclex {
318            // Since we don't support `exec`, this is a NOP. However, we want to
319            // return EBADF if the FD is invalid.
320            if this.machine.fds.is_fd_num(fd_num) {
321                interp_ok(Scalar::from_i32(0))
322            } else {
323                this.set_last_error_and_return_i32(LibcError("EBADF"))
324            }
325        } else {
326            throw_unsup_format!("ioctl: unsupported command {cmd:#x}");
327        }
328    }
329}
miri/shims/unix/macos/foreign_items.rs

miri/shims/unix/macos/
foreign_items.rs
