diff options
| -rw-r--r-- | library/std/src/fs/tests.rs | 16 | ||||
| -rw-r--r-- | library/std/src/sys/unix/fs.rs | 12 |
2 files changed, 26 insertions, 2 deletions
diff --git a/library/std/src/fs/tests.rs b/library/std/src/fs/tests.rs index a62c01ef29b..16b8bf68242 100644 --- a/library/std/src/fs/tests.rs +++ b/library/std/src/fs/tests.rs @@ -1504,3 +1504,19 @@ fn create_dir_long_paths() { let path = Path::new(""); assert_eq!(path.canonicalize().unwrap_err().kind(), crate::io::ErrorKind::NotFound); } + +/// Ensure ReadDir works on large directories. +/// Regression test for https://github.com/rust-lang/rust/issues/93384. +#[test] +fn read_large_dir() { + let tmpdir = tmpdir(); + + let count = 32 * 1024; + for i in 0..count { + check!(fs::File::create(tmpdir.join(&i.to_string()))); + } + + for entry in fs::read_dir(tmpdir.path()).unwrap() { + entry.unwrap(); + } +} diff --git a/library/std/src/sys/unix/fs.rs b/library/std/src/sys/unix/fs.rs index 5b2199c2b7f..65e000d9215 100644 --- a/library/std/src/sys/unix/fs.rs +++ b/library/std/src/sys/unix/fs.rs @@ -489,10 +489,18 @@ impl Iterator for ReadDir { }; } + // Only d_reclen bytes of *entry_ptr are valid, so we can't just copy the + // whole thing (#93384). Instead, copy everything except the name. + let entry_bytes = entry_ptr as *const u8; + let entry_name = ptr::addr_of!((*entry_ptr).d_name) as *const u8; + let name_offset = entry_name.offset_from(entry_bytes) as usize; + let mut entry: dirent64 = mem::zeroed(); + ptr::copy_nonoverlapping(entry_bytes, &mut entry as *mut _ as *mut u8, name_offset); + let ret = DirEntry { - entry: *entry_ptr, + entry, // d_name is guaranteed to be null-terminated. - name: CStr::from_ptr((*entry_ptr).d_name.as_ptr()).to_owned(), + name: CStr::from_ptr(entry_name as *const _).to_owned(), dir: Arc::clone(&self.inner), }; if ret.name_bytes() != b"." && ret.name_bytes() != b".." { |