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rust: validate all linked ELF libraries have annotations
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We added the proper annotations a few commits ago. Here we teach the
validation code to check for it.

Only ELF for the moment because macOS and Windows generally aren't
as big of a problem when it comes to this.
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indygreg committed Oct 17, 2021
1 parent 63c54c2 commit 64407fc
Showing 1 changed file with 81 additions and 8 deletions.
89 changes: 81 additions & 8 deletions src/validation.rs
Original file line number Diff line number Diff line change
Expand Up @@ -401,12 +401,29 @@ fn allowed_dylibs_for_triple(triple: &str) -> Vec<MachOAllowedDylib> {
}

fn validate_elf(
json: &PythonJsonMain,
target_triple: &str,
python_major_minor: &str,
path: &Path,
elf: &goblin::elf::Elf,
bytes: &[u8],
) -> Result<Vec<String>> {
let mut system_links = BTreeSet::new();
for link in &json.build_info.core.links {
if link.system.unwrap_or_default() {
system_links.insert(link.name.as_str());
}
}
for extension in json.build_info.extensions.values() {
for variant in extension {
for link in &variant.links {
if link.system.unwrap_or_default() {
system_links.insert(link.name.as_str());
}
}
}
}

let mut errors = vec![];

let wanted_cpu_type = match target_triple {
Expand Down Expand Up @@ -453,6 +470,48 @@ fn validate_elf(
if !allowed_libraries.contains(&lib.to_string()) {
errors.push(format!("{} loads illegal library {}", path.display(), lib));
}

// Most linked libraries should have an annotation in the JSON metadata.
let requires_annotation = !lib.contains("libpython")
&& !lib.starts_with("ld-linux")
&& !lib.starts_with("ld64.so")
&& !lib.starts_with("ld.so")
&& !lib.starts_with("libc.so")
&& !lib.starts_with("libgcc_s.so");

if requires_annotation {
if lib.starts_with("lib") {
if let Some(index) = lib.rfind(".so") {
let lib_name = &lib[3..index];

// There should be a system links entry for this library in the JSON
// metadata.
//
// Nominally we would look at where this ELF came from and make sure
// the annotation is present in its section (e.g. core or extension).
// But this is more work.
if !system_links.contains(lib_name) {
errors.push(format!(
"{} library load of {} does not have system link build annotation",
path.display(),
lib
));
}
} else {
errors.push(format!(
"{} library load of {} does not have .so extension",
path.display(),
lib
));
}
} else {
errors.push(format!(
"{} library load of {} does not begin with lib",
path.display(),
lib
));
}
}
}

let wanted_glibc_max_version = GLIBC_MAX_VERSION_BY_TRIPLE
Expand Down Expand Up @@ -581,6 +640,7 @@ fn validate_pe(path: &Path, pe: &goblin::pe::PE) -> Result<Vec<String>> {

/// Attempt to parse data as an object file and validate it.
fn validate_possible_object_file(
json: &PythonJsonMain,
python_major_minor: &str,
triple: &str,
path: &Path,
Expand All @@ -593,6 +653,7 @@ fn validate_possible_object_file(
match object {
goblin::Object::Elf(elf) => {
errors.extend(validate_elf(
json,
triple,
python_major_minor,
path.as_ref(),
Expand Down Expand Up @@ -727,17 +788,24 @@ fn validate_distribution(dist_path: &Path) -> Result<Vec<String>> {
let mut entries = tf.entries()?;

let mut wanted_python_paths = BTreeSet::new();
let mut json = None;

let mut entry = entries.next().unwrap()?;
if entry.path()?.display().to_string() == "python/PYTHON.json" {
seen_paths.insert(entry.path()?.to_path_buf());

let mut data = Vec::new();
entry.read_to_end(&mut data)?;
let json = parse_python_json(&data).context("parsing PYTHON.json")?;
errors.extend(validate_json(&json, triple, is_debug)?);

wanted_python_paths.extend(json.python_paths.values().map(|x| format!("python/{}", x)));
json = Some(parse_python_json(&data).context("parsing PYTHON.json")?);
errors.extend(validate_json(json.as_ref().unwrap(), triple, is_debug)?);

wanted_python_paths.extend(
json.as_ref()
.unwrap()
.python_paths
.values()
.map(|x| format!("python/{}", x)),
);
} else {
errors.push(format!(
"1st archive entry should be for python/PYTHON.json; got {}",
Expand Down Expand Up @@ -770,8 +838,13 @@ fn validate_distribution(dist_path: &Path) -> Result<Vec<String>> {
let mut data = Vec::new();
entry.read_to_end(&mut data)?;

let (local_errors, local_seen_dylibs) =
validate_possible_object_file(python_major_minor, &triple, &path, &data)?;
let (local_errors, local_seen_dylibs) = validate_possible_object_file(
json.as_ref().unwrap(),
python_major_minor,
&triple,
&path,
&data,
)?;
errors.extend(local_errors);
seen_dylibs.extend(local_seen_dylibs);

Expand All @@ -790,6 +863,7 @@ fn validate_distribution(dist_path: &Path) -> Result<Vec<String>> {
));

let (local_errors, local_seen_dylibs) = validate_possible_object_file(
json.as_ref().unwrap(),
python_major_minor,
&triple,
&member_path,
Expand All @@ -801,8 +875,7 @@ fn validate_distribution(dist_path: &Path) -> Result<Vec<String>> {
}

if path == PathBuf::from("python/PYTHON.json") {
let json = parse_python_json(&data).context("parsing PYTHON.json")?;
errors.extend(validate_json(&json, triple, is_debug)?);
errors.push("python/PYTHON.json seen twice".to_string());
}
}

Expand Down

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