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

miri/shims/unix/freebsd/
foreign_items.rs
