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Correct fcntl behavior

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This commit is contained in:
Christian Poveda 2019-10-12 20:12:26 -05:00
parent d73fae1b28
commit f76f8ce63b
1 changed files with 11 additions and 6 deletions
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17
src/shims/fs.rs
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@ -9,7 +9,6 @@ use crate::*;
pub struct FileHandle {
file: File,
flag: i32,
}
pub struct FileHandler {
@ -79,13 +78,14 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx
}
let o_cloexec = this.eval_libc_i32("O_CLOEXEC")?;
if flag & o_cloexec != 0 {
// This flag is a noop for now because `std` already sets it.
// We do not need to do anything for this flag because `std` already sets it.
// (Technically we do not support *not* setting this flag, but we ignore that.)
mirror |= o_cloexec;
}
// If `flag` is not equal to `mirror`, there is an unsupported option enabled in `flag`,
// then we throw an error.
if flag != mirror {
throw_unsup_format!("unsupported flags {:#x}", flag);
throw_unsup_format!("unsupported flags {:#x}", flag & !mirror);
}
let path_bytes = this
@ -97,7 +97,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx
let fd = options.open(path).map(|file| {
let mut fh = &mut this.machine.file_handler;
fh.low += 1;
fh.handles.insert(fh.low, FileHandle { file, flag });
fh.handles.insert(fh.low, FileHandle { file });
fh.low
});
@ -108,7 +108,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx
&mut self,
fd_op: OpTy<'tcx, Tag>,
cmd_op: OpTy<'tcx, Tag>,
_arg_op: Option<OpTy<'tcx, Tag>>,
_arg1_op: Option<OpTy<'tcx, Tag>>,
) -> InterpResult<'tcx, i32> {
let this = self.eval_context_mut();
@ -120,7 +120,12 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx
let cmd = this.read_scalar(cmd_op)?.to_i32()?;
// We only support getting the flags for a descriptor
if cmd == this.eval_libc_i32("F_GETFD")? {
this.get_handle_and(fd, |handle| Ok(handle.flag))
// Currently this is the only flag that `F_GETFD` returns. It is OK to just return the
// `FD_CLOEXEC` value without checking if the flag is set for the file because `std`
// always sets this flag when opening a file. However we still need to check that the
// file itself is open.
this.get_handle_and(fd, |_| Ok(0))?;
this.eval_libc_i32("FD_CLOEXEC")
} else {
throw_unsup_format!("The {:#x} command is not supported for `fcntl`)", cmd);
}