miri/shims/unix/freebsd/
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 _;
7use crate::shims::unix::*;
8use crate::*;
9
10pub fn is_dyn_sym(_name: &str) -> bool {
11    false
12}
13
14impl<'tcx> EvalContextExt<'tcx> for crate::MiriInterpCx<'tcx> {}
15pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
16    fn emulate_foreign_item_inner(
17        &mut self,
18        link_name: Symbol,
19        abi: &FnAbi<'tcx, Ty<'tcx>>,
20        args: &[OpTy<'tcx>],
21        dest: &MPlaceTy<'tcx>,
22    ) -> InterpResult<'tcx, EmulateItemResult> {
23        let this = self.eval_context_mut();
24        match link_name.as_str() {
25            // Threading
26            "pthread_setname_np" => {
27                let [thread, name] =
28                    this.check_shim_sig_lenient(abi, CanonAbi::C, link_name, args)?;
29                let max_len = u64::MAX; // FreeBSD does not seem to have a limit.
30                let res = match this.pthread_setname_np(
31                    this.read_scalar(thread)?,
32                    this.read_scalar(name)?,
33                    max_len,
34                    /* truncate */ false,
35                )? {
36                    ThreadNameResult::Ok => Scalar::from_u32(0),
37                    ThreadNameResult::NameTooLong => unreachable!(),
38                    ThreadNameResult::ThreadNotFound => this.eval_libc("ESRCH"),
39                };
40                this.write_scalar(res, dest)?;
41            }
42            "pthread_getname_np" => {
43                let [thread, name, len] =
44                    this.check_shim_sig_lenient(abi, CanonAbi::C, link_name, args)?;
45                // FreeBSD's pthread_getname_np uses strlcpy, which truncates the resulting value,
46                // but always adds a null terminator (except for zero-sized buffers).
47                // https://github.com/freebsd/freebsd-src/blob/c2d93a803acef634bd0eede6673aeea59e90c277/lib/libthr/thread/thr_info.c#L119-L144
48                let res = match this.pthread_getname_np(
49                    this.read_scalar(thread)?,
50                    this.read_scalar(name)?,
51                    this.read_scalar(len)?,
52                    /* truncate */ true,
53                )? {
54                    ThreadNameResult::Ok => Scalar::from_u32(0),
55                    // `NameTooLong` is possible when the buffer is zero sized,
56                    ThreadNameResult::NameTooLong => Scalar::from_u32(0),
57                    ThreadNameResult::ThreadNotFound => this.eval_libc("ESRCH"),
58                };
59                this.write_scalar(res, dest)?;
60            }
61            "pthread_getthreadid_np" => {
62                let [] = this.check_shim_sig_lenient(abi, CanonAbi::C, link_name, args)?;
63                let result = this.unix_gettid(link_name.as_str())?;
64                this.write_scalar(result, dest)?;
65            }
66
67            "cpuset_getaffinity" => {
68                // The "same" kind of api as `sched_getaffinity` but more fine grained control for FreeBSD specifically.
69                let [level, which, id, set_size, mask] =
70                    this.check_shim_sig_lenient(abi, CanonAbi::C, link_name, args)?;
71
72                let level = this.read_scalar(level)?.to_i32()?;
73                let which = this.read_scalar(which)?.to_i32()?;
74                let id = this.read_scalar(id)?.to_i64()?;
75                let set_size = this.read_target_usize(set_size)?; // measured in bytes
76                let mask = this.read_pointer(mask)?;
77
78                let _level_root = this.eval_libc_i32("CPU_LEVEL_ROOT");
79                let _level_cpuset = this.eval_libc_i32("CPU_LEVEL_CPUSET");
80                let level_which = this.eval_libc_i32("CPU_LEVEL_WHICH");
81
82                let _which_tid = this.eval_libc_i32("CPU_WHICH_TID");
83                let which_pid = this.eval_libc_i32("CPU_WHICH_PID");
84                let _which_jail = this.eval_libc_i32("CPU_WHICH_JAIL");
85                let _which_cpuset = this.eval_libc_i32("CPU_WHICH_CPUSET");
86                let _which_irq = this.eval_libc_i32("CPU_WHICH_IRQ");
87
88                // For sched_getaffinity, the current process is identified by -1.
89                // TODO: Use gettid? I'm (LorrensP-2158466) not that familiar with this api .
90                let id = match id {
91                    -1 => this.active_thread(),
92                    _ =>
93                        throw_unsup_format!(
94                            "`cpuset_getaffinity` is only supported with a pid of -1 (indicating the current thread)"
95                        ),
96                };
97
98                if this.ptr_is_null(mask)? {
99                    this.set_last_error_and_return(LibcError("EFAULT"), dest)?;
100                }
101                // We only support CPU_LEVEL_WHICH and CPU_WHICH_PID for now.
102                // This is the bare minimum to make the tests pass.
103                else if level != level_which || which != which_pid {
104                    throw_unsup_format!(
105                        "`cpuset_getaffinity` is only supported with `level` set to CPU_LEVEL_WHICH and `which` set to CPU_WHICH_PID."
106                    );
107                } else if let Some(cpuset) = this.machine.thread_cpu_affinity.get(&id) {
108                    // `cpusetsize` must be large enough to contain the entire CPU mask.
109                    // FreeBSD only uses `cpusetsize` to verify that it's sufficient for the kernel's CPU mask.
110                    // If it's too small, the syscall returns ERANGE.
111                    // If it's large enough, copying the kernel mask to user space is safe, regardless of the actual size.
112                    // See https://github.com/freebsd/freebsd-src/blob/909aa6781340f8c0b4ae01c6366bf1556ee2d1be/sys/kern/kern_cpuset.c#L1985
113                    if set_size < u64::from(this.machine.num_cpus).div_ceil(8) {
114                        this.set_last_error_and_return(LibcError("ERANGE"), dest)?;
115                    } else {
116                        let cpuset = cpuset.clone();
117                        let byte_count =
118                            Ord::min(cpuset.as_slice().len(), set_size.try_into().unwrap());
119                        this.write_bytes_ptr(
120                            mask,
121                            cpuset.as_slice()[..byte_count].iter().copied(),
122                        )?;
123                        this.write_null(dest)?;
124                    }
125                } else {
126                    // `id` is always that of the active thread, so this is currently unreachable.
127                    unreachable!();
128                }
129            }
130
131            // Synchronization primitives
132            "_umtx_op" => {
133                let [obj, op, val, uaddr, uaddr2] =
134                    this.check_shim_sig_lenient(abi, CanonAbi::C, link_name, args)?;
135                this._umtx_op(obj, op, val, uaddr, uaddr2, dest)?;
136            }
137
138            // File related shims
139            // For those, we both intercept `func` and `call@FBSD_1.0` symbols cases
140            // since freebsd 12 the former form can be expected.
141            "stat" | "stat@FBSD_1.0" => {
142                let [path, buf] = this.check_shim_sig_lenient(abi, CanonAbi::C, link_name, args)?;
143                let result = this.macos_fbsd_solarish_stat(path, buf)?;
144                this.write_scalar(result, dest)?;
145            }
146            "lstat" | "lstat@FBSD_1.0" => {
147                let [path, buf] = this.check_shim_sig_lenient(abi, CanonAbi::C, link_name, args)?;
148                let result = this.macos_fbsd_solarish_lstat(path, buf)?;
149                this.write_scalar(result, dest)?;
150            }
151            "fstat" | "fstat@FBSD_1.0" => {
152                let [fd, buf] = this.check_shim_sig_lenient(abi, CanonAbi::C, link_name, args)?;
153                let result = this.macos_fbsd_solarish_fstat(fd, buf)?;
154                this.write_scalar(result, dest)?;
155            }
156            "readdir_r" | "readdir_r@FBSD_1.0" => {
157                let [dirp, entry, result] =
158                    this.check_shim_sig_lenient(abi, CanonAbi::C, link_name, args)?;
159                let result = this.macos_fbsd_readdir_r(dirp, entry, result)?;
160                this.write_scalar(result, dest)?;
161            }
162
163            // Miscellaneous
164            "__error" => {
165                let [] = this.check_shim_sig_lenient(abi, CanonAbi::C, link_name, args)?;
166                let errno_place = this.last_error_place()?;
167                this.write_scalar(errno_place.to_ref(this).to_scalar(), dest)?;
168            }
169
170            // Incomplete shims that we "stub out" just to get pre-main initialization code to work.
171            // These shims are enabled only when the caller is in the standard library.
172            "pthread_attr_get_np" if this.frame_in_std() => {
173                let [_thread, _attr] =
174                    this.check_shim_sig_lenient(abi, CanonAbi::C, link_name, args)?;
175                this.write_null(dest)?;
176            }
177
178            _ => return interp_ok(EmulateItemResult::NotSupported),
179        }
180        interp_ok(EmulateItemResult::NeedsReturn)
181    }
182}
miri/shims/unix/freebsd/foreign_items.rs

miri/shims/unix/freebsd/
foreign_items.rs
