lockdep: Use "WARNING" tag on lockdep splats
authorPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Tue, 31 Jan 2017 15:45:13 +0000 (07:45 -0800)
committerPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Wed, 19 Apr 2017 16:27:29 +0000 (09:27 -0700)
This commit changes lockdep splats to begin lines with "WARNING" and
to use pr_warn() instead of printk().  This change eases scripted
analysis of kernel console output.

Reported-by: Dmitry Vyukov <dvyukov@google.com>
Reported-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Dmitry Vyukov <dvyukov@google.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
kernel/locking/lockdep.c
kernel/locking/rtmutex-debug.c

index a95e5d1..e9d4f85 100644 (file)
@@ -1144,10 +1144,10 @@ print_circular_bug_header(struct lock_list *entry, unsigned int depth,
                return 0;
 
        printk("\n");
-       printk("======================================================\n");
-       printk("[ INFO: possible circular locking dependency detected ]\n");
+       pr_warn("======================================================\n");
+       pr_warn("WARNING: possible circular locking dependency detected\n");
        print_kernel_ident();
-       printk("-------------------------------------------------------\n");
+       pr_warn("------------------------------------------------------\n");
        printk("%s/%d is trying to acquire lock:\n",
                curr->comm, task_pid_nr(curr));
        print_lock(check_src);
@@ -1482,11 +1482,11 @@ print_bad_irq_dependency(struct task_struct *curr,
                return 0;
 
        printk("\n");
-       printk("======================================================\n");
-       printk("[ INFO: %s-safe -> %s-unsafe lock order detected ]\n",
+       pr_warn("=====================================================\n");
+       pr_warn("WARNING: %s-safe -> %s-unsafe lock order detected\n",
                irqclass, irqclass);
        print_kernel_ident();
-       printk("------------------------------------------------------\n");
+       pr_warn("-----------------------------------------------------\n");
        printk("%s/%d [HC%u[%lu]:SC%u[%lu]:HE%u:SE%u] is trying to acquire:\n",
                curr->comm, task_pid_nr(curr),
                curr->hardirq_context, hardirq_count() >> HARDIRQ_SHIFT,
@@ -1711,10 +1711,10 @@ print_deadlock_bug(struct task_struct *curr, struct held_lock *prev,
                return 0;
 
        printk("\n");
-       printk("=============================================\n");
-       printk("[ INFO: possible recursive locking detected ]\n");
+       pr_warn("============================================\n");
+       pr_warn("WARNING: possible recursive locking detected\n");
        print_kernel_ident();
-       printk("---------------------------------------------\n");
+       pr_warn("--------------------------------------------\n");
        printk("%s/%d is trying to acquire lock:\n",
                curr->comm, task_pid_nr(curr));
        print_lock(next);
@@ -2061,10 +2061,10 @@ static void print_collision(struct task_struct *curr,
                        struct lock_chain *chain)
 {
        printk("\n");
-       printk("======================\n");
-       printk("[chain_key collision ]\n");
+       pr_warn("============================\n");
+       pr_warn("WARNING: chain_key collision\n");
        print_kernel_ident();
-       printk("----------------------\n");
+       pr_warn("----------------------------\n");
        printk("%s/%d: ", current->comm, task_pid_nr(current));
        printk("Hash chain already cached but the contents don't match!\n");
 
@@ -2360,10 +2360,10 @@ print_usage_bug(struct task_struct *curr, struct held_lock *this,
                return 0;
 
        printk("\n");
-       printk("=================================\n");
-       printk("[ INFO: inconsistent lock state ]\n");
+       pr_warn("================================\n");
+       pr_warn("WARNING: inconsistent lock state\n");
        print_kernel_ident();
-       printk("---------------------------------\n");
+       pr_warn("--------------------------------\n");
 
        printk("inconsistent {%s} -> {%s} usage.\n",
                usage_str[prev_bit], usage_str[new_bit]);
@@ -2425,10 +2425,10 @@ print_irq_inversion_bug(struct task_struct *curr,
                return 0;
 
        printk("\n");
-       printk("=========================================================\n");
-       printk("[ INFO: possible irq lock inversion dependency detected ]\n");
+       pr_warn("========================================================\n");
+       pr_warn("WARNING: possible irq lock inversion dependency detected\n");
        print_kernel_ident();
-       printk("---------------------------------------------------------\n");
+       pr_warn("--------------------------------------------------------\n");
        printk("%s/%d just changed the state of lock:\n",
                curr->comm, task_pid_nr(curr));
        print_lock(this);
@@ -3170,10 +3170,10 @@ print_lock_nested_lock_not_held(struct task_struct *curr,
                return 0;
 
        printk("\n");
-       printk("==================================\n");
-       printk("[ BUG: Nested lock was not taken ]\n");
+       pr_warn("==================================\n");
+       pr_warn("WARNING: Nested lock was not taken\n");
        print_kernel_ident();
-       printk("----------------------------------\n");
+       pr_warn("----------------------------------\n");
 
        printk("%s/%d is trying to lock:\n", curr->comm, task_pid_nr(curr));
        print_lock(hlock);
@@ -3383,10 +3383,10 @@ print_unlock_imbalance_bug(struct task_struct *curr, struct lockdep_map *lock,
                return 0;
 
        printk("\n");
-       printk("=====================================\n");
-       printk("[ BUG: bad unlock balance detected! ]\n");
+       pr_warn("=====================================\n");
+       pr_warn("WARNING: bad unlock balance detected!\n");
        print_kernel_ident();
-       printk("-------------------------------------\n");
+       pr_warn("-------------------------------------\n");
        printk("%s/%d is trying to release lock (",
                curr->comm, task_pid_nr(curr));
        print_lockdep_cache(lock);
@@ -3880,10 +3880,10 @@ print_lock_contention_bug(struct task_struct *curr, struct lockdep_map *lock,
                return 0;
 
        printk("\n");
-       printk("=================================\n");
-       printk("[ BUG: bad contention detected! ]\n");
+       pr_warn("=================================\n");
+       pr_warn("WARNING: bad contention detected!\n");
        print_kernel_ident();
-       printk("---------------------------------\n");
+       pr_warn("---------------------------------\n");
        printk("%s/%d is trying to contend lock (",
                curr->comm, task_pid_nr(curr));
        print_lockdep_cache(lock);
@@ -4244,10 +4244,10 @@ print_freed_lock_bug(struct task_struct *curr, const void *mem_from,
                return;
 
        printk("\n");
-       printk("=========================\n");
-       printk("[ BUG: held lock freed! ]\n");
+       pr_warn("=========================\n");
+       pr_warn("WARNING: held lock freed!\n");
        print_kernel_ident();
-       printk("-------------------------\n");
+       pr_warn("-------------------------\n");
        printk("%s/%d is freeing memory %p-%p, with a lock still held there!\n",
                curr->comm, task_pid_nr(curr), mem_from, mem_to-1);
        print_lock(hlock);
@@ -4302,11 +4302,11 @@ static void print_held_locks_bug(void)
                return;
 
        printk("\n");
-       printk("=====================================\n");
-       printk("[ BUG: %s/%d still has locks held! ]\n",
+       pr_warn("====================================\n");
+       pr_warn("WARNING: %s/%d still has locks held!\n",
               current->comm, task_pid_nr(current));
        print_kernel_ident();
-       printk("-------------------------------------\n");
+       pr_warn("------------------------------------\n");
        lockdep_print_held_locks(current);
        printk("\nstack backtrace:\n");
        dump_stack();
@@ -4371,7 +4371,7 @@ retry:
        } while_each_thread(g, p);
 
        printk("\n");
-       printk("=============================================\n\n");
+       pr_warn("=============================================\n\n");
 
        if (unlock)
                read_unlock(&tasklist_lock);
@@ -4401,10 +4401,10 @@ asmlinkage __visible void lockdep_sys_exit(void)
                if (!debug_locks_off())
                        return;
                printk("\n");
-               printk("================================================\n");
-               printk("[ BUG: lock held when returning to user space! ]\n");
+               pr_warn("================================================\n");
+               pr_warn("WARNING: lock held when returning to user space!\n");
                print_kernel_ident();
-               printk("------------------------------------------------\n");
+               pr_warn("------------------------------------------------\n");
                printk("%s/%d is leaving the kernel with locks still held!\n",
                                curr->comm, curr->pid);
                lockdep_print_held_locks(curr);
@@ -4421,13 +4421,13 @@ void lockdep_rcu_suspicious(const char *file, const int line, const char *s)
 #endif /* #ifdef CONFIG_PROVE_RCU_REPEATEDLY */
        /* Note: the following can be executed concurrently, so be careful. */
        printk("\n");
-       pr_err("===============================\n");
-       pr_err("[ ERR: suspicious RCU usage.  ]\n");
+       pr_warn("=============================\n");
+       pr_warn("WARNING: suspicious RCU usage\n");
        print_kernel_ident();
-       pr_err("-------------------------------\n");
-       pr_err("%s:%d %s!\n", file, line, s);
-       pr_err("\nother info that might help us debug this:\n\n");
-       pr_err("\n%srcu_scheduler_active = %d, debug_locks = %d\n",
+       pr_warn("-----------------------------\n");
+       printk("%s:%d %s!\n", file, line, s);
+       printk("\nother info that might help us debug this:\n\n");
+       printk("\n%srcu_scheduler_active = %d, debug_locks = %d\n",
               !rcu_lockdep_current_cpu_online()
                        ? "RCU used illegally from offline CPU!\n"
                        : !rcu_is_watching()
index 97ee9df..db4f552 100644 (file)
@@ -102,10 +102,11 @@ void debug_rt_mutex_print_deadlock(struct rt_mutex_waiter *waiter)
                return;
        }
 
-       printk("\n============================================\n");
-       printk(  "[ BUG: circular locking deadlock detected! ]\n");
-       printk("%s\n", print_tainted());
-       printk(  "--------------------------------------------\n");
+       pr_warn("\n");
+       pr_warn("============================================\n");
+       pr_warn("WARNING: circular locking deadlock detected!\n");
+       pr_warn("%s\n", print_tainted());
+       pr_warn("--------------------------------------------\n");
        printk("%s/%d is deadlocking current task %s/%d\n\n",
               task->comm, task_pid_nr(task),
               current->comm, task_pid_nr(current));