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_deprecated(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                };
39                this.write_scalar(res, dest)?;
40            }
41            "pthread_getname_np" => {
42                let [thread, name, len] =
43                    this.check_shim_sig_deprecated(abi, CanonAbi::C, link_name, args)?;
44                // FreeBSD's pthread_getname_np uses strlcpy, which truncates the resulting value,
45                // but always adds a null terminator (except for zero-sized buffers).
46                // https://github.com/freebsd/freebsd-src/blob/c2d93a803acef634bd0eede6673aeea59e90c277/lib/libthr/thread/thr_info.c#L119-L144
47                let res = match this.pthread_getname_np(
48                    this.read_scalar(thread)?,
49                    this.read_scalar(name)?,
50                    this.read_scalar(len)?,
51                    /* truncate */ true,
52                )? {
53                    ThreadNameResult::Ok => Scalar::from_u32(0),
54                    // `NameTooLong` is possible when the buffer is zero sized,
55                    ThreadNameResult::NameTooLong => Scalar::from_u32(0),
56                };
57                this.write_scalar(res, dest)?;
58            }
59            "pthread_getthreadid_np" => {
60                let [] = this.check_shim_sig_deprecated(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_sig_deprecated(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                if this.machine.thread_cpu_affinity.is_none() {
77                    throw_unsup_format!(
78                        "`cpuset_getaffinity` is not supported on #![no_core] programs"
79                    )
80                }
81
82                let _level_root = this.eval_libc_i32("CPU_LEVEL_ROOT");
83                let _level_cpuset = this.eval_libc_i32("CPU_LEVEL_CPUSET");
84                let level_which = this.eval_libc_i32("CPU_LEVEL_WHICH");
85
86                let _which_tid = this.eval_libc_i32("CPU_WHICH_TID");
87                let which_pid = this.eval_libc_i32("CPU_WHICH_PID");
88                let _which_jail = this.eval_libc_i32("CPU_WHICH_JAIL");
89                let _which_cpuset = this.eval_libc_i32("CPU_WHICH_CPUSET");
90                let _which_irq = this.eval_libc_i32("CPU_WHICH_IRQ");
91
92                // For sched_getaffinity, the current process is identified by -1.
93                // TODO: Use gettid? I'm (LorrensP-2158466) not that familiar with this api .
94                let id = match id {
95                    -1 => this.active_thread(),
96                    _ =>
97                        throw_unsup_format!(
98                            "`cpuset_getaffinity` is only supported with a pid of -1 (indicating the current thread)"
99                        ),
100                };
101
102                if this.ptr_is_null(mask)? {
103                    this.set_errno_and_return_neg1(LibcError("EFAULT"), dest)?;
104                }
105                // We only support CPU_LEVEL_WHICH and CPU_WHICH_PID for now.
106                // This is the bare minimum to make the tests pass.
107                else if level != level_which || which != which_pid {
108                    throw_unsup_format!(
109                        "`cpuset_getaffinity` is only supported with `level` set to CPU_LEVEL_WHICH and `which` set to CPU_WHICH_PID."
110                    );
111                } else if let Some(cpuset) =
112                    this.machine.thread_cpu_affinity.as_ref().unwrap().get(&id)
113                {
114                    // `cpusetsize` must be large enough to contain the entire CPU mask.
115                    // FreeBSD only uses `cpusetsize` to verify that it's sufficient for the kernel's CPU mask.
116                    // If it's too small, the syscall returns ERANGE.
117                    // If it's large enough, copying the kernel mask to user space is safe, regardless of the actual size.
118                    // See https://github.com/freebsd/freebsd-src/blob/909aa6781340f8c0b4ae01c6366bf1556ee2d1be/sys/kern/kern_cpuset.c#L1985
119                    if set_size < u64::from(this.machine.num_cpus).div_ceil(8) {
120                        this.set_errno_and_return_neg1(LibcError("ERANGE"), dest)?;
121                    } else {
122                        let cpuset = cpuset.clone();
123                        let byte_count =
124                            Ord::min(cpuset.as_slice().len(), set_size.try_into().unwrap());
125                        this.write_bytes_ptr(
126                            mask,
127                            cpuset.as_slice()[..byte_count].iter().copied(),
128                        )?;
129                        this.write_null(dest)?;
130                    }
131                } else {
132                    // `id` is always that of the active thread, so this is currently unreachable.
133                    unreachable!();
134                }
135            }
136
137            // Synchronization primitives
138            "_umtx_op" => {
139                let [obj, op, val, uaddr, uaddr2] =
140                    this.check_shim_sig_deprecated(abi, CanonAbi::C, link_name, args)?;
141                this._umtx_op(obj, op, val, uaddr, uaddr2, dest)?;
142            }
143
144            // File related shims
145            "stat@FBSD_1.0" => {
146                let [path, buf] =
147                    this.check_shim_sig_deprecated(abi, CanonAbi::C, link_name, args)?;
148                let result = this.stat(path, buf)?;
149                this.write_scalar(result, dest)?;
150            }
151            "lstat@FBSD_1.0" => {
152                let [path, buf] =
153                    this.check_shim_sig_deprecated(abi, CanonAbi::C, link_name, args)?;
154                let result = this.lstat(path, buf)?;
155                this.write_scalar(result, dest)?;
156            }
157            "fstat@FBSD_1.0" => {
158                let [fd, buf] =
159                    this.check_shim_sig_deprecated(abi, CanonAbi::C, link_name, args)?;
160                let result = this.fstat(fd, buf)?;
161                this.write_scalar(result, dest)?;
162            }
163            "readdir@FBSD_1.0" => {
164                let [dirp] = this.check_shim_sig_deprecated(abi, CanonAbi::C, link_name, args)?;
165                this.readdir(dirp, dest)?;
166            }
167            // Miscellaneous
168            "__error" => {
169                let [] = this.check_shim_sig_deprecated(abi, CanonAbi::C, link_name, args)?;
170                let errno_place = this.last_error_place()?;
171                this.write_scalar(errno_place.to_ref(this).to_scalar(), dest)?;
172            }
173            "__xuname" => {
174                // FreeBSD uses __xuname under the hood to implement uname, see:
175                // https://github.com/freebsd/freebsd-src/blob/3542d60fb8042474f66fbf2d779ed8c5a80d0f78/sys/sys/utsname.h#L64
176                // https://github.com/freebsd/freebsd-src/blob/3542d60fb8042474f66fbf2d779ed8c5a80d0f78/lib/libc/gen/uname.c#L44
177                let [size, uname] = this.check_shim_sig(
178                    shim_sig!(extern "C" fn(i32, *_) -> i32),
179                    (link_name, abi, args),
180                )?;
181                let result = this.uname(uname, Some(size))?;
182                this.write_scalar(result, dest)?;
183            }
184
185            // Incomplete shims that we "stub out" just to get pre-main initialization code to work.
186            // These shims are enabled only when the caller is in the standard library.
187            "pthread_attr_get_np" if this.frame_in_std() => {
188                let [_thread, _attr] =
189                    this.check_shim_sig_deprecated(abi, CanonAbi::C, link_name, args)?;
190                this.write_null(dest)?;
191            }
192
193            _ => return interp_ok(EmulateItemResult::NotSupported),
194        }
195        interp_ok(EmulateItemResult::NeedsReturn)
196    }
197}
miri/shims/unix/freebsd/foreign_items.rs

miri/shims/unix/freebsd/
foreign_items.rs
