# First, let's check if the file exists and get its total line count
wc -l crates/vm/src/stdlib/io.rs

# Read the specific lines mentioned in the review (5339 and 5764-5786)
# Start with line 5339
sed -n '5335,5345p' crates/vm/src/stdlib/io.rs

# Read the lines 5764-5786 to see the full context of the issue
sed -n '5760,5790p' crates/vm/src/stdlib/io.rs

# Also check around line 5767 mentioned in the comment
sed -n '5760,5800p' crates/vm/src/stdlib/io.rs

# Search for crt_fd module usage and definition
rg "crt_fd" crates/vm/src/stdlib/io.rs | head -20

# Check the Rust std::io::Read documentation behavior - search for how read_to_end is used elsewhere
rg "read_to_end" crates/vm/src/stdlib/io.rs

# Look for crt_fd module definition
fd "crt_fd" crates/

# Check if there's a read function being used with crt_fd elsewhere
rg "crt_fd::read" crates/vm/src/stdlib/io.rs

# Search for DEFAULT_BUFFER_SIZE constant
rg "DEFAULT_BUFFER_SIZE" crates/vm/src/stdlib/io.rs | head -5

# Check the crt_fd module to understand the read function
cat crates/common/src/crt_fd.rs

# Look for the context where crt_fd::read is used in that loop
rg -B5 -A5 "crt_fd::read\(handle" crates/vm/src/stdlib/io.rs

-                let mut bytes = vec![];
-                // Loop on EINTR (PEP 475)
-                loop {
-                    match vm.allow_threads(|| {
-                        let mut h = handle;
-                        h.read_to_end(&mut bytes)
-                    }) {
-                        Ok(_) => break,
-                        Err(e) if e.raw_os_error() == Some(libc::EINTR) => {
-                            vm.check_signals()?;
-                            continue;
-                        }
-                        // Non-blocking mode: return None if EAGAIN (only if no data read yet)
-                        Err(e) if e.raw_os_error() == Some(libc::EAGAIN) => {
-                            if bytes.is_empty() {
-                                return Ok(None);
-                            }
-                            break;
-                        }
-                        Err(e) => return Err(Self::io_error(zelf, e, vm)),
-                    }
-                }
+                let mut bytes = vec![];
+                loop {
+                    let mut chunk = vec![0; super::DEFAULT_BUFFER_SIZE];
+                    match vm.allow_threads(|| crt_fd::read(handle, &mut chunk)) {
+                        Ok(0) => break,
+                        Ok(n) => bytes.extend_from_slice(&chunk[..n]),
+                        Err(e) if e.raw_os_error() == Some(libc::EINTR) => {
+                            vm.check_signals()?;
+                            continue;
+                        }
+                        Err(e) if e.raw_os_error() == Some(libc::EAGAIN) => {
+                            if bytes.is_empty() {
+                                return Ok(None);
+                            }
+                            break;
+                        }
+                        Err(e) => return Err(Self::io_error(zelf, e, vm)),
+                    }
+                }

Verify each finding against the current code and only fix it if needed.

In `@crates/vm/src/stdlib/io.rs` at line 5339, The code currently uses
std::io::Read::read_to_end(), which hides EINTR and prevents vm.check_signals()
from running on the unbounded-read path (size < 0); replace that call with an
explicit chunked loop that uses crt_fd::read() to fill a Vec<u8> (read
fixed-size chunks, e.g., 8KiB), append each successful chunk to the buffer,
break on EOF (0 bytes), and on read errors return Err so EINTR is propagated to
the outer error handler; make sure to reference and replace the read_to_end()
call site and keep vm.check_signals() semantics by letting crt_fd::read()
surface EINTR instead of swallowing it.