rust/src/shims/dlsym.rs

65 lines
2.1 KiB
Rust

use rustc_middle::mir;
use crate::*;
use helpers::check_arg_count;
#[derive(Debug, Copy, Clone)]
pub enum Dlsym {
GetEntropy,
}
impl Dlsym {
// Returns an error for unsupported symbols, and None if this symbol
// should become a NULL pointer (pretend it does not exist).
pub fn from_str(name: &[u8], target_os: &str) -> InterpResult<'static, Option<Dlsym>> {
use self::Dlsym::*;
let name = String::from_utf8_lossy(name);
Ok(match target_os {
"linux" => match &*name {
"__pthread_get_minstack" => None,
_ => throw_unsup_format!("unsupported Linux dlsym: {}", name),
}
"macos" => match &*name {
"getentropy" => Some(GetEntropy),
_ => throw_unsup_format!("unsupported macOS dlsym: {}", name),
}
"windows" => match &*name {
"SetThreadStackGuarantee" => None,
"AcquireSRWLockExclusive" => None,
"GetSystemTimePreciseAsFileTime" => None,
_ => throw_unsup_format!("unsupported Windows dlsym: {}", name),
}
os => bug!("dlsym not implemented for target_os {}", os),
})
}
}
impl<'mir, 'tcx: 'mir> EvalContextExt<'mir, 'tcx> for crate::MiriEvalContext<'mir, 'tcx> {}
pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx> {
fn call_dlsym(
&mut self,
dlsym: Dlsym,
args: &[OpTy<'tcx, Tag>],
ret: Option<(PlaceTy<'tcx, Tag>, mir::BasicBlock)>,
) -> InterpResult<'tcx> {
use self::Dlsym::*;
let this = self.eval_context_mut();
let (dest, ret) = ret.expect("we don't support any diverging dlsym");
match dlsym {
GetEntropy => {
let &[ptr, len] = check_arg_count(args)?;
let ptr = this.read_scalar(ptr)?.not_undef()?;
let len = this.read_scalar(len)?.to_machine_usize(this)?;
this.gen_random(ptr, len)?;
this.write_null(dest)?;
}
}
this.dump_place(*dest);
this.go_to_block(ret);
Ok(())
}
}