From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964968AbdDSPAk (ORCPT ); Wed, 19 Apr 2017 11:00:40 -0400 Received: from relay4-d.mail.gandi.net ([217.70.183.196]:33082 "EHLO relay4-d.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S964958AbdDSPAf (ORCPT ); Wed, 19 Apr 2017 11:00:35 -0400 Date: Wed, 19 Apr 2017 08:00:22 -0700 From: Josh Triplett To: "Paul E. McKenney" Cc: linux-kernel@vger.kernel.org, mingo@kernel.org, jiangshanlai@gmail.com, dipankar@in.ibm.com, akpm@linux-foundation.org, mathieu.desnoyers@efficios.com, tglx@linutronix.de, peterz@infradead.org, rostedt@goodmis.org, dhowells@redhat.com, edumazet@google.com, fweisbec@gmail.com, oleg@redhat.com, bobby.prani@gmail.com Subject: Re: [PATCH v2 tip/core/rcu 02/11] lockdep: Use "WARNING" tag on lockdep splats Message-ID: <20170419150022.GB17080@cloud> References: <20170417232714.GA19013@linux.vnet.ibm.com> <1492471738-1377-2-git-send-email-paulmck@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1492471738-1377-2-git-send-email-paulmck@linux.vnet.ibm.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Apr 17, 2017 at 04:28:49PM -0700, Paul E. McKenney wrote: > 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 > Reported-by: Ingo Molnar > Signed-off-by: Paul E. McKenney > Acked-by: Dmitry Vyukov Reviewed-by: Josh Triplett Any reason not to change the adjacent calls to printk (without a priority) to pr_warn? > kernel/locking/lockdep.c | 86 +++++++++++++++++++++--------------------- > kernel/locking/rtmutex-debug.c | 9 +++-- > 2 files changed, 48 insertions(+), 47 deletions(-) > > diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c > index a95e5d1f4a9c..e9d4f85b290c 100644 > --- a/kernel/locking/lockdep.c > +++ b/kernel/locking/lockdep.c > @@ -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 @@ 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); > @@ -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() > diff --git a/kernel/locking/rtmutex-debug.c b/kernel/locking/rtmutex-debug.c > index 97ee9df32e0f..db4f55211b04 100644 > --- a/kernel/locking/rtmutex-debug.c > +++ b/kernel/locking/rtmutex-debug.c > @@ -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)); > -- > 2.5.2 >