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Fix writing errors

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This commit is contained in:
Christian Poveda 2019-10-18 14:25:49 -05:00
parent 85941c7249
commit 0201cc5587
1 changed files with 10 additions and 13 deletions
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23
src/helpers.rs
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@ -353,22 +353,19 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx
fn write_os_str_to_c_string(&mut self, os_str: &OsStr, ptr: Pointer<Tag>, size: u64) -> InterpResult<'tcx> {
let bytes = os_str_to_bytes(os_str)?;
let len = bytes.len();
// If `size` is smaller or equal than `bytes.len()`, writing `bytes` plus the required null
// terminator to memory using the `ptr` pointer would cause an overflow.
if (bytes.len() as u64) < size {
if (len as u64) < size {
let this = self.eval_context_mut();
let tcx = &{ this.tcx.tcx };
let buffer = this.memory.get_mut(ptr.alloc_id)?.get_bytes_mut(tcx, ptr, Size::from_bytes(len as u64 + 1))?;
buffer[..len].copy_from_slice(bytes);
// This is ok because the buffer was strictly larger than `bytes`, so after adding the
// null terminator, the buffer size is larger or equal to `bytes.len()`, meaning that
// `bytes` actually fit inside tbe buffer.
this.memory
.get_mut(ptr.alloc_id)?
.write_bytes(tcx, ptr, &bytes)?;
// We write the `/0` terminator
let tail_ptr = ptr.offset(Size::from_bytes(bytes.len() as u64 + 1), this)?;
this.memory
.get_mut(ptr.alloc_id)?
.write_bytes(tcx, tail_ptr, b"0")
buffer[len] = 0;
Ok(())
} else {
throw_unsup_format!("OsString is larger than destination")
}
@ -376,13 +373,13 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx
}
#[cfg(target_os = "unix")]
fn bytes_to_os_str<'tcx, 'a>(bytes: &'a[u8]) -> InterpResult<'tcx, &'a OsStr> {
Ok(std::os::unix::ffi::OsStringExt::from_bytes(bytes))
fn os_str_to_bytes<'tcx, 'a>(os_str: &'a OsStr) -> InterpResult<'tcx, &'a [u8]> {
std::os::unix::ffi::OsStringExt::into_bytes(os_str)
}
#[cfg(target_os = "unix")]
fn os_str_to_bytes<'tcx, 'a>(os_str: &'a OsStr) -> InterpResult<'tcx, &'a [u8]> {
std::os::unix::ffi::OsStringExt::into_bytes(os_str)
fn bytes_to_os_str<'tcx, 'a>(bytes: &'a[u8]) -> InterpResult<'tcx, &'a OsStr> {
Ok(std::os::unix::ffi::OsStringExt::from_bytes(bytes))
}
// On non-unix platforms the best we can do to transform bytes from/to OS strings is to do the