src/shims/windows/dlsym.rs

   1 use rustc_middle::mir;
   2 use rustc_target::abi::Size;
   3 use rustc_target::spec::abi::Abi;
   4
   5 use log::trace;
   6
   7 use crate::helpers::check_arg_count;
   8 use crate::*;
   9
  10 #[derive(Debug, Copy, Clone)]
  11 pub enum Dlsym {
  12     NtWriteFile,
  13 }
  14
  15 impl Dlsym {
  16     // Returns an error for unsupported symbols, and None if this symbol
  17     // should become a NULL pointer (pretend it does not exist).
  18     pub fn from_str(name: &str) -> InterpResult<'static, Option<Dlsym>> {
  19         Ok(match name {
  20             "GetSystemTimePreciseAsFileTime" => None,
  21             "NtWriteFile" => Some(Dlsym::NtWriteFile),
  22             _ => throw_unsup_format!("unsupported Windows dlsym: {}", name),
  23         })
  24     }
  25 }
  26
  27 impl<'mir, 'tcx: 'mir> EvalContextExt<'mir, 'tcx> for crate::MiriEvalContext<'mir, 'tcx> {}
  28 pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx> {
  29     fn call_dlsym(
  30         &mut self,
  31         dlsym: Dlsym,
  32         abi: Abi,
  33         args: &[OpTy<'tcx, Tag>],
  34         ret: Option<(&PlaceTy<'tcx, Tag>, mir::BasicBlock)>,
  35     ) -> InterpResult<'tcx> {
  36         let this = self.eval_context_mut();
  37         let (dest, ret) = ret.expect("we don't support any diverging dlsym");
  38         assert!(this.tcx.sess.target.os == "windows");
  39
  40         this.check_abi(abi, Abi::System { unwind: false })?;
  41
  42         match dlsym {
  43             Dlsym::NtWriteFile => {
  44                 if !this.frame_in_std() {
  45                     throw_unsup_format!(
  46                         "NtWriteFile support is crude and just enough for stdout to work"
  47                     );
  48                 }
  49
  50                 let [
  51                     handle,
  52                     _event,
  53                     _apc_routine,
  54                     _apc_context,
  55                     io_status_block,
  56                     buf,
  57                     n,
  58                     byte_offset,
  59                     _key,
  60                 ] = check_arg_count(args)?;
  61                 let handle = this.read_scalar(handle)?.to_machine_isize(this)?;
  62                 let buf = this.read_pointer(buf)?;
  63                 let n = this.read_scalar(n)?.to_u32()?;
  64                 let byte_offset = this.read_scalar(byte_offset)?.to_machine_usize(this)?; // is actually a pointer
  65                 let io_status_block = this.deref_operand(io_status_block)?;
  66
  67                 if byte_offset != 0 {
  68                     throw_unsup_format!(
  69                         "NtWriteFile ByteOffset paremeter is non-null, which is unsupported"
  70                     );
  71                 }
  72
  73                 let written = if handle == -11 || handle == -12 {
  74                     // stdout/stderr
  75                     use std::io::{self, Write};
  76
  77                     let buf_cont = this.read_bytes_ptr(buf, Size::from_bytes(u64::from(n)))?;
  78                     let res = if handle == -11 {
  79                         io::stdout().write(buf_cont)
  80                     } else {
  81                         io::stderr().write(buf_cont)
  82                     };
  83                     res.ok().map(|n| n as u32)
  84                 } else {
  85                     throw_unsup_format!(
  86                         "on Windows, writing to anything except stdout/stderr is not supported"
  87                     )
  88                 };
  89                 // We have to put the result into io_status_block.
  90                 if let Some(n) = written {
  91                     let io_status_information =
  92                         this.mplace_field_named(&io_status_block, "Information")?;
  93                     this.write_scalar(
  94                         Scalar::from_machine_usize(n.into(), this),
  95                         &io_status_information.into(),
  96                     )?;
  97                 }
  98                 // Return whether this was a success. >= 0 is success.
  99                 // For the error code we arbitrarily pick 0xC0000185, STATUS_IO_DEVICE_ERROR.
 100                 this.write_scalar(
 101                     Scalar::from_i32(if written.is_some() { 0 } else { 0xC0000185u32 as i32 }),
 102                     dest,
 103                 )?;
 104             }
 105         }
 106
 107         trace!("{:?}", this.dump_place(**dest));
 108         this.go_to_block(ret);
 109         Ok(())
 110     }
 111 }