lockdep: Fix report formatting

Since commit:

  4bcc595 ("printk: reinstate KERN_CONT for printing continuation lines")

printk() requires KERN_CONT to continue log messages. Lots of printk()
in lockdep.c and print_ip_sym() don't have it. As the result lockdep
reports are completely messed up.

Add missing KERN_CONT and inline print_ip_sym() where necessary.

Example of a messed up report:

  0-rc5+ #41 Not tainted
  -------------------------------------------------------
  syz-executor0/5036 is trying to acquire lock:
   (
  rtnl_mutex
  ){+.+.+.}
  , at:
  [<ffffffff86b3d6ac>] rtnl_lock+0x1c/0x20
  but task is already holding lock:
   (
  &net->packet.sklist_lock
  ){+.+...}
  , at:
  [<ffffffff873541a6>] packet_diag_dump+0x1a6/0x1920
  which lock already depends on the new lock.
  the existing dependency chain (in reverse order) is:
  -> #3
   (
  &net->packet.sklist_lock
  +.+...}
  ...

Without this patch all scripts that parse kernel bug reports are broken.

Signed-off-by: Dmitry Vyukov <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>

Author: dvyukov

kernel/locking/lockdep.c

@@ -506,13 +506,13 @@ static void __print_lock_name(struct lock_class *class)
 	name = class->name;
 	if (!name) {
 		name = __get_key_name(class->key, str);
-		printk("%s", name);
+		printk(KERN_CONT "%s", name);
 	} else {
-		printk("%s", name);
+		printk(KERN_CONT "%s", name);
 		if (class->name_version > 1)
-			printk("#%d", class->name_version);
+			printk(KERN_CONT "#%d", class->name_version);
 		if (class->subclass)
-			printk("/%d", class->subclass);
+			printk(KERN_CONT "/%d", class->subclass);
 	}
 }
 
@@ -522,9 +522,9 @@ static void print_lock_name(struct lock_class *class)
 
 	get_usage_chars(class, usage);
 
-	printk(" (");
+	printk(KERN_CONT " (");
 	__print_lock_name(class);
-	printk("){%s}", usage);
+	printk(KERN_CONT "){%s}", usage);
 }
 
 static void print_lockdep_cache(struct lockdep_map *lock)
@@ -536,7 +536,7 @@ static void print_lockdep_cache(struct lockdep_map *lock)
 	if (!name)
 		name = __get_key_name(lock->key->subkeys, str);
 
-	printk("%s", name);
+	printk(KERN_CONT "%s", name);
 }
 
 static void print_lock(struct held_lock *hlock)
@@ -551,13 +551,13 @@ static void print_lock(struct held_lock *hlock)
 	barrier();
 
 	if (!class_idx || (class_idx - 1) >= MAX_LOCKDEP_KEYS) {
-		printk("<RELEASED>\n");
+		printk(KERN_CONT "<RELEASED>\n");
 		return;
 	}
 
 	print_lock_name(lock_classes + class_idx - 1);
-	printk(", at: ");
-	print_ip_sym(hlock->acquire_ip);
+	printk(KERN_CONT ", at: [<%p>] %pS\n",
+		(void *)hlock->acquire_ip, (void *)hlock->acquire_ip);
 }
 
 static void lockdep_print_held_locks(struct task_struct *curr)
@@ -792,8 +792,8 @@ register_lock_class(struct lockdep_map *lock, unsigned int subclass, int force)
 
 		printk("\nnew class %p: %s", class->key, class->name);
 		if (class->name_version > 1)
-			printk("#%d", class->name_version);
-		printk("\n");
+			printk(KERN_CONT "#%d", class->name_version);
+		printk(KERN_CONT "\n");
 		dump_stack();
 
 		if (!graph_lock()) {
@@ -1071,7 +1071,7 @@ print_circular_bug_entry(struct lock_list *target, int depth)
 		return 0;
 	printk("\n-> #%u", depth);
 	print_lock_name(target->class);
-	printk(":\n");
+	printk(KERN_CONT ":\n");
 	print_stack_trace(&target->trace, 6);
 
 	return 0;
@@ -1102,28 +1102,28 @@ print_circular_lock_scenario(struct held_lock *src,
 	if (parent != source) {
 		printk("Chain exists of:\n  ");
 		__print_lock_name(source);
-		printk(" --> ");
+		printk(KERN_CONT " --> ");
 		__print_lock_name(parent);
-		printk(" --> ");
+		printk(KERN_CONT " --> ");
 		__print_lock_name(target);
-		printk("\n\n");
+		printk(KERN_CONT "\n\n");
 	}
 
 	printk(" Possible unsafe locking scenario:\n\n");
 	printk("       CPU0                    CPU1\n");
 	printk("       ----                    ----\n");
 	printk("  lock(");
 	__print_lock_name(target);
-	printk(");\n");
+	printk(KERN_CONT ");\n");
 	printk("                               lock(");
 	__print_lock_name(parent);
-	printk(");\n");
+	printk(KERN_CONT ");\n");
 	printk("                               lock(");
 	__print_lock_name(target);
-	printk(");\n");
+	printk(KERN_CONT ");\n");
 	printk("  lock(");
 	__print_lock_name(source);
-	printk(");\n");
+	printk(KERN_CONT ");\n");
 	printk("\n *** DEADLOCK ***\n\n");
 }
 
@@ -1359,22 +1359,22 @@ static void print_lock_class_header(struct lock_class *class, int depth)
 
 	printk("%*s->", depth, "");
 	print_lock_name(class);
-	printk(" ops: %lu", class->ops);
-	printk(" {\n");
+	printk(KERN_CONT " ops: %lu", class->ops);
+	printk(KERN_CONT " {\n");
 
 	for (bit = 0; bit < LOCK_USAGE_STATES; bit++) {
 		if (class->usage_mask & (1 << bit)) {
 			int len = depth;
 
 			len += printk("%*s   %s", depth, "", usage_str[bit]);
-			len += printk(" at:\n");
+			len += printk(KERN_CONT " at:\n");
 			print_stack_trace(class->usage_traces + bit, len);
 		}
 	}
 	printk("%*s }\n", depth, "");
 
-	printk("%*s ... key      at: ",depth,"");
-	print_ip_sym((unsigned long)class->key);
+	printk("%*s ... key      at: [<%p>] %pS\n",
+		depth, "", class->key, class->key);
 }
 
 /*
@@ -1437,30 +1437,30 @@ print_irq_lock_scenario(struct lock_list *safe_entry,
 	if (middle_class != unsafe_class) {
 		printk("Chain exists of:\n  ");
 		__print_lock_name(safe_class);
-		printk(" --> ");
+		printk(KERN_CONT " --> ");
 		__print_lock_name(middle_class);
-		printk(" --> ");
+		printk(KERN_CONT " --> ");
 		__print_lock_name(unsafe_class);
-		printk("\n\n");
+		printk(KERN_CONT "\n\n");
 	}
 
 	printk(" Possible interrupt unsafe locking scenario:\n\n");
 	printk("       CPU0                    CPU1\n");
 	printk("       ----                    ----\n");
 	printk("  lock(");
 	__print_lock_name(unsafe_class);
-	printk(");\n");
+	printk(KERN_CONT ");\n");
 	printk("                               local_irq_disable();\n");
 	printk("                               lock(");
 	__print_lock_name(safe_class);
-	printk(");\n");
+	printk(KERN_CONT ");\n");
 	printk("                               lock(");
 	__print_lock_name(middle_class);
-	printk(");\n");
+	printk(KERN_CONT ");\n");
 	printk("  <Interrupt>\n");
 	printk("    lock(");
 	__print_lock_name(safe_class);
-	printk(");\n");
+	printk(KERN_CONT ");\n");
 	printk("\n *** DEADLOCK ***\n\n");
 }
 
@@ -1497,9 +1497,9 @@ print_bad_irq_dependency(struct task_struct *curr,
 	print_lock(prev);
 	printk("which would create a new lock dependency:\n");
 	print_lock_name(hlock_class(prev));
-	printk(" ->");
+	printk(KERN_CONT " ->");
 	print_lock_name(hlock_class(next));
-	printk("\n");
+	printk(KERN_CONT "\n");
 
 	printk("\nbut this new dependency connects a %s-irq-safe lock:\n",
 		irqclass);
@@ -1521,8 +1521,7 @@ print_bad_irq_dependency(struct task_struct *curr,
 
 	lockdep_print_held_locks(curr);
 
-	printk("\nthe dependencies between %s-irq-safe lock", irqclass);
-	printk(" and the holding lock:\n");
+	printk("\nthe dependencies between %s-irq-safe lock and the holding lock:\n", irqclass);
 	if (!save_trace(&prev_root->trace))
 		return 0;
 	print_shortest_lock_dependencies(backwards_entry, prev_root);
@@ -1694,10 +1693,10 @@ print_deadlock_scenario(struct held_lock *nxt,
 	printk("       ----\n");
 	printk("  lock(");
 	__print_lock_name(prev);
-	printk(");\n");
+	printk(KERN_CONT ");\n");
 	printk("  lock(");
 	__print_lock_name(next);
-	printk(");\n");
+	printk(KERN_CONT ");\n");
 	printk("\n *** DEADLOCK ***\n\n");
 	printk(" May be due to missing lock nesting notation\n\n");
 }
@@ -1891,9 +1890,9 @@ check_prev_add(struct task_struct *curr, struct held_lock *prev,
 		graph_unlock();
 		printk("\n new dependency: ");
 		print_lock_name(hlock_class(prev));
-		printk(" => ");
+		printk(KERN_CONT " => ");
 		print_lock_name(hlock_class(next));
-		printk("\n");
+		printk(KERN_CONT "\n");
 		dump_stack();
 		return graph_lock();
 	}
@@ -2343,11 +2342,11 @@ print_usage_bug_scenario(struct held_lock *lock)
 	printk("       ----\n");
 	printk("  lock(");
 	__print_lock_name(class);
-	printk(");\n");
+	printk(KERN_CONT ");\n");
 	printk("  <Interrupt>\n");
 	printk("    lock(");
 	__print_lock_name(class);
-	printk(");\n");
+	printk(KERN_CONT ");\n");
 	printk("\n *** DEADLOCK ***\n\n");
 }
 
@@ -2522,14 +2521,18 @@ check_usage_backwards(struct task_struct *curr, struct held_lock *this,
 void print_irqtrace_events(struct task_struct *curr)
 {
 	printk("irq event stamp: %u\n", curr->irq_events);
-	printk("hardirqs last  enabled at (%u): ", curr->hardirq_enable_event);
-	print_ip_sym(curr->hardirq_enable_ip);
-	printk("hardirqs last disabled at (%u): ", curr->hardirq_disable_event);
-	print_ip_sym(curr->hardirq_disable_ip);
-	printk("softirqs last  enabled at (%u): ", curr->softirq_enable_event);
-	print_ip_sym(curr->softirq_enable_ip);
-	printk("softirqs last disabled at (%u): ", curr->softirq_disable_event);
-	print_ip_sym(curr->softirq_disable_ip);
+	printk("hardirqs last  enabled at (%u): [<%p>] %pS\n",
+		curr->hardirq_enable_event, (void *)curr->hardirq_enable_ip,
+		(void *)curr->hardirq_enable_ip);
+	printk("hardirqs last disabled at (%u): [<%p>] %pS\n",
+		curr->hardirq_disable_event, (void *)curr->hardirq_disable_ip,
+		(void *)curr->hardirq_disable_ip);
+	printk("softirqs last  enabled at (%u): [<%p>] %pS\n",
+		curr->softirq_enable_event, (void *)curr->softirq_enable_ip,
+		(void *)curr->softirq_enable_ip);
+	printk("softirqs last disabled at (%u): [<%p>] %pS\n",
+		curr->softirq_disable_event, (void *)curr->softirq_disable_ip,
+		(void *)curr->softirq_disable_ip);
 }
 
 static int HARDIRQ_verbose(struct lock_class *class)
@@ -3235,8 +3238,8 @@ static int __lock_acquire(struct lockdep_map *lock, unsigned int subclass,
 	if (very_verbose(class)) {
 		printk("\nacquire class [%p] %s", class->key, class->name);
 		if (class->name_version > 1)
-			printk("#%d", class->name_version);
-		printk("\n");
+			printk(KERN_CONT "#%d", class->name_version);
+		printk(KERN_CONT "\n");
 		dump_stack();
 	}
 
@@ -3378,7 +3381,7 @@ print_unlock_imbalance_bug(struct task_struct *curr, struct lockdep_map *lock,
 	printk("%s/%d is trying to release lock (",
 		curr->comm, task_pid_nr(curr));
 	print_lockdep_cache(lock);
-	printk(") at:\n");
+	printk(KERN_CONT ") at:\n");
 	print_ip_sym(ip);
 	printk("but there are no more locks to release!\n");
 	printk("\nother info that might help us debug this:\n");
@@ -3871,7 +3874,7 @@ print_lock_contention_bug(struct task_struct *curr, struct lockdep_map *lock,
 	printk("%s/%d is trying to contend lock (",
 		curr->comm, task_pid_nr(curr));
 	print_lockdep_cache(lock);
-	printk(") at:\n");
+	printk(KERN_CONT ") at:\n");
 	print_ip_sym(ip);
 	printk("but there are no locks held!\n");
 	printk("\nother info that might help us debug this:\n");