From: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
To: Ingo Molnar <mingo@kernel.org>
Cc: Dmitry Vyukov <dvyukov@google.com>,
"H. Peter Anvin" <hpa@zytor.com>,
LKML <linux-kernel@vger.kernel.org>,
Thomas Gleixner <tglx@linutronix.de>,
linux-tip-commits@vger.kernel.org
Subject: Re: [tip:core/rcu] lockdep: Make RCU suspicious-access splats use pr_err
Date: Tue, 31 Jan 2017 07:49:45 -0800 [thread overview]
Message-ID: <20170131154945.GF30506@linux.vnet.ibm.com> (raw)
In-Reply-To: <20170131091757.GA3940@gmail.com>
On Tue, Jan 31, 2017 at 10:17:57AM +0100, Ingo Molnar wrote:
>
> * Dmitry Vyukov <dvyukov@google.com> wrote:
>
> > FWIW my vote is for:
> >
> > ==========================
> > WARNING: suspicious RCU usage
> > ==========================
>
> For heaven's sake make it:
>
> =============================
> WARNING: suspicious RCU usage
> =============================
>
> (Note the length of the start/stop lines.)
Like this?
Thanx, Paul
------------------------------------------------------------------------
commit 45a2b28bb464a88ea886759c23a3cfa9b9b10055
Author: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Date: Tue Jan 31 07:45:13 2017 -0800
lockdep: Use "WARNING" tag on lockdep splats
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>
diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
index d9a698e8458f..330648980789 100644
--- a/kernel/locking/lockdep.c
+++ b/kernel/locking/lockdep.c
@@ -1142,10 +1142,10 @@ 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);
@@ -1480,11 +1480,11 @@ 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,
@@ -1709,10 +1709,10 @@ 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);
@@ -2059,10 +2059,10 @@ 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");
@@ -2358,10 +2358,10 @@ 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]);
@@ -2423,10 +2423,10 @@ 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);
@@ -3168,10 +3168,10 @@ 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);
@@ -3374,10 +3374,10 @@ 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);
@@ -3871,10 +3871,10 @@ 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);
@@ -4235,10 +4235,10 @@ 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);
@@ -4293,11 +4293,11 @@ 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();
@@ -4362,7 +4362,7 @@ void debug_show_all_locks(void)
} while_each_thread(g, p);
printk("\n");
- printk("=============================================\n\n");
+ pr_warn("=============================================\n\n");
if (unlock)
read_unlock(&tasklist_lock);
@@ -4392,10 +4392,10 @@ 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);
@@ -4412,13 +4412,13 @@ 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()
diff --git a/kernel/locking/rtmutex-debug.c b/kernel/locking/rtmutex-debug.c
index 62b6cee8ea7f..7f8a9e2ced6e 100644
--- a/kernel/locking/rtmutex-debug.c
+++ b/kernel/locking/rtmutex-debug.c
@@ -101,10 +101,11 @@ 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));
next prev parent reply other threads:[~2017-01-31 15:50 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <tip-4d4f88fa235f7f9ef8213564dc1804144332238b@git.kernel.org>
2017-01-31 8:09 ` [tip:core/rcu] lockdep: Make RCU suspicious-access splats use pr_err Dmitry Vyukov
2017-01-31 8:51 ` Ingo Molnar
2017-01-31 9:11 ` Dmitry Vyukov
2017-01-31 9:17 ` Ingo Molnar
2017-01-31 15:49 ` Paul E. McKenney [this message]
2017-02-01 11:07 ` Dmitry Vyukov
2017-02-01 15:49 ` Paul E. McKenney
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