diff options
| -rw-r--r-- | src/tools/miri/src/shims/unix/fd.rs | 26 | ||||
| -rw-r--r-- | src/tools/miri/src/shims/unix/fs.rs | 4 | ||||
| -rw-r--r-- | src/tools/miri/src/shims/unix/unnamed_socket.rs | 8 |
3 files changed, 25 insertions, 13 deletions
diff --git a/src/tools/miri/src/shims/unix/fd.rs b/src/tools/miri/src/shims/unix/fd.rs index 5f719991b37..4b87ce60c8b 100644 --- a/src/tools/miri/src/shims/unix/fd.rs +++ b/src/tools/miri/src/shims/unix/fd.rs @@ -26,7 +26,9 @@ pub trait FileDescription: std::fmt::Debug + Any { fn name(&self) -> &'static str; /// Reads as much as possible into the given buffer, and returns the number of bytes read. - /// `ptr` is the pointer to user supplied read buffer. + /// `ptr` is the pointer to the user supplied read buffer. + /// `len` indicates how many bytes the user requested. + /// `dest` is where the return value should be stored. fn read<'tcx>( &self, _self_ref: &FileDescriptionRef, @@ -40,6 +42,8 @@ pub trait FileDescription: std::fmt::Debug + Any { } /// Writes as much as possible from the given buffer, and returns the number of bytes written. + /// `bytes` is the buffer of bytes supplied by the caller to be written. + /// `dest` is where the return value should be stored. fn write<'tcx>( &self, _self_ref: &FileDescriptionRef, @@ -53,6 +57,9 @@ pub trait FileDescription: std::fmt::Debug + Any { /// Reads as much as possible into the given buffer from a given offset, /// and returns the number of bytes read. + /// `ptr` is the pointer to the user supplied read buffer. + /// `len` indicates how many bytes the user requested. + /// `dest` is where the return value should be stored. fn pread<'tcx>( &self, _communicate_allowed: bool, @@ -67,6 +74,8 @@ pub trait FileDescription: std::fmt::Debug + Any { /// Writes as much as possible from the given buffer starting at a given offset, /// and returns the number of bytes written. + /// `bytes` is the buffer of bytes supplied by the caller to be written. + /// `dest` is where the return value should be stored. fn pwrite<'tcx>( &self, _communicate_allowed: bool, @@ -143,7 +152,7 @@ impl FileDescription for io::Stdin { helpers::isolation_abort_error("`read` from stdin")?; } let result = Read::read(&mut { self }, &mut bytes); - ecx.return_read_bytes_and_count(ptr, bytes, result, dest) + ecx.return_read_bytes_and_count(ptr, &bytes, result, dest) } fn is_tty(&self, communicate_allowed: bool) -> bool { @@ -641,12 +650,15 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> { Ok(()) } - /// This function either writes to the user supplied buffer and to dest place, or sets the - /// last libc error and writes -1 to dest. + /// Helper to implement `FileDescription::read`: + /// `result` should be the return value of some underlying `read` call that used `bytes` as its output buffer. + /// The length of `bytes` must not exceed either the host's or the target's `isize`. + /// If `Result` indicates success, `bytes` is written to `buf` and the size is written to `dest`. + /// Otherwise, `-1` is written to `dest` and the last libc error is set appropriately. fn return_read_bytes_and_count( &mut self, buf: Pointer, - bytes: Vec<u8>, + bytes: &[u8], result: io::Result<usize>, dest: &MPlaceTy<'tcx>, ) -> InterpResult<'tcx> { @@ -657,7 +669,7 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> { // Crucially, if fewer than `bytes.len()` bytes were read, only write // that much into the output buffer! this.write_bytes_ptr(buf, bytes[..read_bytes].iter().copied())?; - // The actual read size is always lesser than `count` so this cannot fail. + // The actual read size is always less than what got originally requested so this cannot fail. this.write_int(u64::try_from(read_bytes).unwrap(), dest)?; return Ok(()); } @@ -669,7 +681,7 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> { } } - /// This function writes the number of written bytes to dest place, or sets the + /// This function writes the number of written bytes (given in `result`) to `dest`, or sets the /// last libc error and writes -1 to dest. fn return_written_byte_count_or_error( &mut self, diff --git a/src/tools/miri/src/shims/unix/fs.rs b/src/tools/miri/src/shims/unix/fs.rs index cf709d5e6da..e1ac9b0adfb 100644 --- a/src/tools/miri/src/shims/unix/fs.rs +++ b/src/tools/miri/src/shims/unix/fs.rs @@ -42,7 +42,7 @@ impl FileDescription for FileHandle { assert!(communicate_allowed, "isolation should have prevented even opening a file"); let mut bytes = vec![0; usize::try_from(len).unwrap()]; let result = (&mut &self.file).read(&mut bytes); - ecx.return_read_bytes_and_count(ptr, bytes.to_vec(), result, dest) + ecx.return_read_bytes_and_count(ptr, &bytes, result, dest) } fn write<'tcx>( @@ -83,7 +83,7 @@ impl FileDescription for FileHandle { res }; let result = f(); - ecx.return_read_bytes_and_count(ptr, bytes.to_vec(), result, dest) + ecx.return_read_bytes_and_count(ptr, &bytes, result, dest) } fn pwrite<'tcx>( diff --git a/src/tools/miri/src/shims/unix/unnamed_socket.rs b/src/tools/miri/src/shims/unix/unnamed_socket.rs index 76350254e30..d5b061ea3cd 100644 --- a/src/tools/miri/src/shims/unix/unnamed_socket.rs +++ b/src/tools/miri/src/shims/unix/unnamed_socket.rs @@ -137,7 +137,7 @@ impl FileDescription for AnonSocket { // Always succeed on read size 0. if request_byte_size == 0 { let result = Ok(0); - return ecx.return_read_bytes_and_count(ptr, bytes.to_vec(), result, dest); + return ecx.return_read_bytes_and_count(ptr, &bytes, result, dest); } let Some(readbuf) = &self.readbuf else { @@ -151,7 +151,7 @@ impl FileDescription for AnonSocket { // Socketpair with no peer and empty buffer. // 0 bytes successfully read indicates end-of-file. let result = Ok(0); - return ecx.return_read_bytes_and_count(ptr, bytes.to_vec(), result, dest); + return ecx.return_read_bytes_and_count(ptr, &bytes, result, dest); } else { if self.is_nonblock { // Non-blocking socketpair with writer and empty buffer. @@ -160,7 +160,7 @@ impl FileDescription for AnonSocket { // POSIX.1-2001 allows either error to be returned for this case. // Since there is no ErrorKind for EAGAIN, WouldBlock is used. let result = Err(Error::from(ErrorKind::WouldBlock)); - return ecx.return_read_bytes_and_count(ptr, bytes.to_vec(), result, dest); + return ecx.return_read_bytes_and_count(ptr, &bytes, result, dest); } else { // Blocking socketpair with writer and empty buffer. // FIXME: blocking is currently not supported @@ -193,7 +193,7 @@ impl FileDescription for AnonSocket { } let result = Ok(actual_read_size); - ecx.return_read_bytes_and_count(ptr, bytes.to_vec(), result, dest) + ecx.return_read_bytes_and_count(ptr, &bytes, result, dest) } fn write<'tcx>( |