lockdep: Fix report formatting

Since commit:

  4bcc595ccd80 ("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 <dvyukov@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: andreyknvl@google.com
Cc: aryabinin@virtuozzo.com
Cc: joe@perches.com
Cc: syzkaller@googlegroups.com
Link: http://lkml.kernel.org/r/1480343083-48731-1-git-send-email-dvyukov@google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
index 589d763a49b3952322f08c00286675f314a3f76c..4d7ffc0a0d0069af114da7c795967d695a135e14 100644 (file)
--- a/kernel/locking/lockdep.c
+++ b/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;
@@ -1102,11 +1102,11 @@ 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");
@@ -1114,16 +1114,16 @@ print_circular_lock_scenario(struct held_lock *src,
        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);
 }
 
 /*
@@ -1437,11 +1437,11 @@ 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");
@@ -1449,18 +1449,18 @@ print_irq_lock_scenario(struct lock_list *safe_entry,
        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");