Moved deadlock scanning to lock module

Author: Pranav-Agarwal0612

.pre-commit-config.yaml

@@ -15,7 +15,7 @@ repos:
     rev: "23.7.0"
     hooks:
     -   id: black
-        args: [--line-length=79]
+        args: ['--line-length=79', '--diff']
 -   repo: https://github.com/pycqa/flake8
     rev: "6.1.0"
     hooks:

drgn_tools/deadlock.py

@@ -1,6 +1,5 @@
 # Copyright (c) 2025, Oracle and/or its affiliates.
 # Licensed under the Universal Permissive License v 1.0 as shown at https://oss.oracle.com/licenses/upl/
-import argparse
 from typing import Dict
 from typing import List
 from typing import Optional
@@ -9,12 +8,8 @@
 from typing import Union
 
 from drgn import Object
-from drgn import Program
 from drgn import TypeKind
 
-from drgn_tools.corelens import CorelensModule
-from drgn_tools.lock import get_mutex_lock_info
-
 
 class DependencyGraph:
     class Node:
@@ -30,9 +25,9 @@ def from_object(cls, object: Object):
                 )
 
             object_node = cls.get_node(
-                name=type_.typename(), address=object.address_
+                name=type_.type_name(), address=object.address_
             )
-            if not object_node.object:
+            if object_node.object is None:
                 object_node.object = object
             return object_node
 
@@ -46,7 +41,7 @@ def __init__(
             self.address: int = address
             self.depends_on: List[DependencyGraph.Node] = []
             self.blocked_nodes: List[DependencyGraph.Node] = []
-            self.object: Object = None
+            self.object: Optional[Object] = None
 
         def __hash__(self):
             # Using name (example : "struct task_struct") and address as unique
@@ -58,7 +53,7 @@ def get_node(cls, name: str, address: int):
             hash_value = hash((name, address))
             if hash_value in DependencyGraph.node_map:
                 return DependencyGraph.node_map[hash_value]
-            return cls(name, address)
+            return cls(name=name, address=address)
 
     node_map: Dict[int, Node] = dict()
 
@@ -117,20 +112,3 @@ def dfs(start_node: DependencyGraph.Node) -> None:
                 dfs(node)
 
         return cycles
-
-
-class Deadlock(CorelensModule):
-    name = "deadlock"
-
-    def add_args(self, parser: argparse.ArgumentParser) -> None:
-        pass
-
-    def run(self, prog: Program, args: argparse.Namespace) -> None:
-        graph: DependencyGraph = DependencyGraph()
-        get_mutex_lock_info(prog, stack=False, graph=graph)
-        cycles = graph.detect_cycle()
-        if not cycles:
-            print("No cycle found")
-            return
-        for cycle in cycles:
-            print(cycle)

drgn_tools/lock.py

@@ -123,9 +123,9 @@ def _addr_info(prog: Program, addr: int):
 def get_mutex_lock_info(
     prog: Program,
     stack: bool,
+    graph: DependencyGraph,
     time: Optional[int] = None,
     pid: Optional[int] = None,
-    graph: Optional[DependencyGraph] = None,
 ) -> None:
     """Scan for mutex and show details"""
     wtask = None
@@ -158,11 +158,10 @@ def get_mutex_lock_info(
 
         struct_owner = mutex_owner(prog, mutex)
         index = 0
-        if graph:
-            graph.add_edge(
-                DependencyGraph.Node.from_object(struct_owner),
-                DependencyGraph.Node.from_object(mutex),
-            )
+        graph.add_edge(
+            DependencyGraph.Node.from_object(struct_owner),
+            DependencyGraph.Node.from_object(mutex),
+        )
 
         if pid is None:
             if time is None:
@@ -173,19 +172,17 @@ def get_mutex_lock_info(
                 index = index + 1
 
                 if waittime > timens or timens == 0:
-                    if graph:
-                        graph.add_edge(
-                            DependencyGraph.Node.from_object(mutex),
-                            DependencyGraph.Node.from_object(waiter),
-                        )
+                    graph.add_edge(
+                        DependencyGraph.Node.from_object(mutex),
+                        DependencyGraph.Node.from_object(waiter),
+                    )
                 else:
                     continue
         else:
-            if graph:
-                graph.add_edge(
-                    DependencyGraph.Node.from_object(mutex),
-                    DependencyGraph.Node.from_object(wtask),
-                )
+            graph.add_edge(
+                DependencyGraph.Node.from_object(mutex),
+                DependencyGraph.Node.from_object(wtask),
+            )
 
 
 def scan_mutex_lock(
@@ -453,6 +450,29 @@ def scan_lock(
     scan_rwsem_lock(prog, stack, time, pid)
 
 
+def get_deadlock_info(
+    prog: Program,
+    stack: bool,
+    time: Optional[int] = None,
+    pid: Optional[int] = None,
+) -> None:
+    graph: DependencyGraph = DependencyGraph()
+    get_mutex_lock_info(prog, stack, graph)
+    cycles = graph.detect_cycle()
+    if not cycles:
+        print("No cycle found")
+        return
+
+    print("Cycle Detected!!")
+    cycle_count = 1
+    for cycle in cycles:
+        print(f"---- {cycle_count} ----")
+        for node in cycle:
+            print(f"[{node.name}(0x{node.address:x})]", end=" -> ")
+        print("")
+        cycle_count += 1
+
+
 class Locking(CorelensModule):
     """Display active mutex and semaphores and their waiters"""
 
@@ -490,3 +510,4 @@ def run(self, prog: Program, args: argparse.Namespace) -> None:
             print("Dont filter with both time and PID")
             return
         scan_lock(prog, args.stack, args.time, args.pid)
+        get_deadlock_info(prog, args.stack, args.time, args.pid)