_lockdep_trace: Backtrace,
}
+// Locates the frame preceding the earliest `debug_sync` frame in the call stack. This ensures we
+// can properly detect a lock's construction and acquiral callsites, since the latter may contain
+// multiple `debug_sync` frames.
#[cfg(feature = "backtrace")]
-fn get_construction_location(backtrace: &Backtrace) -> (String, Option<u32>) {
- // Find the first frame that is after `debug_sync` (or that is in our tests) and use
- // that as the mutex construction site. Note that the first few frames may be in
- // the `backtrace` crate, so we have to ignore those.
+fn locate_call_symbol(backtrace: &Backtrace) -> (String, Option<u32>) {
+ // Find the earliest `debug_sync` frame (or that is in our tests) and use the frame preceding it
+ // as the callsite. Note that the first few frames may be in the `backtrace` crate, so we have
+ // to ignore those.
let sync_mutex_constr_regex = regex::Regex::new(r"lightning.*debug_sync").unwrap();
let mut found_debug_sync = false;
- for frame in backtrace.frames() {
- for symbol in frame.symbols() {
- let symbol_name = symbol.name().unwrap().as_str().unwrap();
- if !sync_mutex_constr_regex.is_match(symbol_name) {
- if found_debug_sync {
- return (format!("{}:{}", symbol.filename().unwrap().display(), symbol.lineno().unwrap()), symbol.colno());
- }
- } else { found_debug_sync = true; }
+ let mut symbol_after_latest_debug_sync = None;
+ for frame in backtrace.frames().iter() {
+ for symbol in frame.symbols().iter() {
+ if let Some(symbol_name) = symbol.name().map(|name| name.as_str()).flatten() {
+ if !sync_mutex_constr_regex.is_match(symbol_name) {
+ if found_debug_sync {
+ symbol_after_latest_debug_sync = Some(symbol);
+ found_debug_sync = false;
+ }
+ } else { found_debug_sync = true; }
+ }
}
}
- panic!("Couldn't find mutex construction callsite");
+ let symbol = symbol_after_latest_debug_sync.expect("Couldn't find lock call symbol");
+ (format!("{}:{}", symbol.filename().unwrap().display(), symbol.lineno().unwrap()), symbol.colno())
}
impl LockMetadata {
#[cfg(feature = "backtrace")]
{
let (lock_constr_location, lock_constr_colno) =
- get_construction_location(&res._lock_construction_bt);
+ locate_call_symbol(&res._lock_construction_bt);
LOCKS_INIT.call_once(|| { unsafe { LOCKS = Some(StdMutex::new(HashMap::new())); } });
let mut locks = unsafe { LOCKS.as_ref() }.unwrap().lock().unwrap();
match locks.entry(lock_constr_location) {
hash_map::Entry::Occupied(e) => {
assert_eq!(lock_constr_colno,
- get_construction_location(&e.get()._lock_construction_bt).1,
+ locate_call_symbol(&e.get()._lock_construction_bt).1,
"Because Windows doesn't support column number results in backtraces, we cannot construct two mutexes on the same line or we risk lockorder detection false positives.");
return Arc::clone(e.get())
},
fn pre_lock(this: &Arc<LockMetadata>, _double_lock_self_allowed: bool) {
LOCKS_HELD.with(|held| {
- // For each lock which is currently locked, check that no lock's locked-before
- // set includes the lock we're about to lock, which would imply a lockorder
- // inversion.
+ // For each lock that is currently held, check that no lock's `locked_before` set
+ // includes the lock we're about to hold, which would imply a lockorder inversion.
for (locked_idx, _locked) in held.borrow().iter() {
if *locked_idx == this.lock_idx {
// Note that with `feature = "backtrace"` set, we may be looking at different
#[cfg(feature = "backtrace")]
debug_assert!(_double_lock_self_allowed,
"Tried to acquire a lock while it was held!\nLock constructed at {}",
- get_construction_location(&this._lock_construction_bt).0);
+ locate_call_symbol(&this._lock_construction_bt).0);
#[cfg(not(feature = "backtrace"))]
panic!("Tried to acquire a lock while it was held!");
}
}
for (_locked_idx, locked) in held.borrow().iter() {
for (locked_dep_idx, _locked_dep) in locked.locked_before.lock().unwrap().iter() {
- if *locked_dep_idx == this.lock_idx && *locked_dep_idx != locked.lock_idx {
- #[cfg(feature = "backtrace")]
- panic!("Tried to violate existing lockorder.\nMutex that should be locked after the current lock was created at the following backtrace.\nNote that to get a backtrace for the lockorder violation, you should set RUST_BACKTRACE=1\nLock being taken constructed at: {} ({}):\n{:?}\nLock constructed at: {} ({})\n{:?}\n\nLock dep created at:\n{:?}\n\n",
- get_construction_location(&this._lock_construction_bt).0,
- this.lock_idx, this._lock_construction_bt,
- get_construction_location(&locked._lock_construction_bt).0,
- locked.lock_idx, locked._lock_construction_bt,
- _locked_dep._lockdep_trace);
- #[cfg(not(feature = "backtrace"))]
- panic!("Tried to violate existing lockorder. Build with the backtrace feature for more info.");
+ let is_dep_this_lock = *locked_dep_idx == this.lock_idx;
+ let has_same_construction = *locked_dep_idx == locked.lock_idx;
+ if is_dep_this_lock && !has_same_construction {
+ #[allow(unused_mut, unused_assignments)]
+ let mut has_same_callsite = false;
+ #[cfg(feature = "backtrace")] {
+ has_same_callsite = _double_lock_self_allowed &&
+ locate_call_symbol(&_locked_dep._lockdep_trace) ==
+ locate_call_symbol(&Backtrace::new());
+ }
+ if !has_same_callsite {
+ #[cfg(feature = "backtrace")]
+ panic!("Tried to violate existing lockorder.\nMutex that should be locked after the current lock was created at the following backtrace.\nNote that to get a backtrace for the lockorder violation, you should set RUST_BACKTRACE=1\nLock being taken constructed at: {} ({}):\n{:?}\nLock constructed at: {} ({})\n{:?}\n\nLock dep created at:\n{:?}\n\n",
+ locate_call_symbol(&this._lock_construction_bt).0,
+ this.lock_idx, this._lock_construction_bt,
+ locate_call_symbol(&locked._lock_construction_bt).0,
+ locked.lock_idx, locked._lock_construction_bt,
+ _locked_dep._lockdep_trace);
+ #[cfg(not(feature = "backtrace"))]
+ panic!("Tried to violate existing lockorder. Build with the backtrace feature for more info.");
+ }
}
}
// Insert any already-held locks in our locked-before set.
projects / rust-lightning / blobdiff