From: Peter Zijlstra <peterz@infradead.org>
To: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Petr Mladek <pmladek@suse.com>,
Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>,
Sergey Senozhatsky <sergey.senozhatsky@gmail.com>,
Dmitriy Vyukov <dvyukov@google.com>,
Steven Rostedt <rostedt@goodmis.org>,
Alexander Potapenko <glider@google.com>,
Fengguang Wu <fengguang.wu@intel.com>,
Josh Poimboeuf <jpoimboe@redhat.com>,
LKML <linux-kernel@vger.kernel.org>,
Linus Torvalds <torvalds@linux-foundation.org>,
Andrew Morton <akpm@linux-foundation.org>,
linux-mm@kvack.org, Ingo Molnar <mingo@redhat.com>,
Will Deacon <will.deacon@arm.com>
Subject: Re: [PATCH 3/3] lockdep: Use line-buffered printk() for lockdep messages.
Date: Fri, 2 Nov 2018 14:36:29 +0100 [thread overview]
Message-ID: <20181102133629.GN3178@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <1541165517-3557-3-git-send-email-penguin-kernel@I-love.SAKURA.ne.jp>
On Fri, Nov 02, 2018 at 10:31:57PM +0900, Tetsuo Handa wrote:
> syzbot is sometimes getting mixed output like below due to concurrent
> printk(). Mitigate such output by using line-buffered printk() API.
>
> RCU used illegally from idle CPU!
> rcu_scheduler_active = 2, debug_locks = 1
> RSP: 0018:ffffffff88007bb8 EFLAGS: 00000286
> RCU used illegally from extended quiescent state!
> ORIG_RAX: ffffffffffffff13
> 1 lock held by swapper/1/0:
> RAX: dffffc0000000000 RBX: 1ffffffff1000f7b RCX: 0000000000000000
> #0:
> RDX: 1ffffffff10237b8 RSI: 0000000000000001 RDI: ffffffff8811bdc0
> 000000004b34587c
> RBP: ffffffff88007bb8 R08: ffffffff88075e00 R09: 0000000000000000
> (
> R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
> rcu_read_lock
> R13: ffffffff88007c78 R14: 0000000000000000 R15: 0000000000000000
> ){....}
> arch_safe_halt arch/x86/include/asm/paravirt.h:94 [inline]
> default_idle+0xc2/0x410 arch/x86/kernel/process.c:498
> , at: trace_call_bpf+0xf8/0x640 kernel/trace/bpf_trace.c:46
WTH is that buffered aPI, and no, that breaks my earlyprintk stuff.
next prev parent reply other threads:[~2018-11-02 13:36 UTC|newest]
Thread overview: 54+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-02 13:31 [PATCH v6 1/3] printk: Add line-buffered printk() API Tetsuo Handa
2018-11-02 13:31 ` [PATCH 2/3] mm: Use line-buffered printk() for show_free_areas() Tetsuo Handa
2018-11-07 14:07 ` Petr Mladek
2018-11-02 13:31 ` [PATCH 3/3] lockdep: Use line-buffered printk() for lockdep messages Tetsuo Handa
2018-11-02 13:36 ` Peter Zijlstra [this message]
2018-11-03 2:00 ` Tetsuo Handa
2018-11-06 8:38 ` Petr Mladek
2018-11-06 9:05 ` Sergey Senozhatsky
2018-11-06 12:57 ` Petr Mladek
2018-11-06 9:56 ` Tetsuo Handa
2018-11-07 15:19 ` Petr Mladek
2018-11-08 4:45 ` Sergey Senozhatsky
2018-11-08 11:37 ` Tetsuo Handa
2018-11-09 6:12 ` Sergey Senozhatsky
2018-11-09 9:55 ` Tetsuo Handa
2018-11-09 15:43 ` Petr Mladek
2018-11-10 2:42 ` Tetsuo Handa
2018-11-23 12:46 ` Petr Mladek
2018-11-23 13:12 ` Tetsuo Handa
2018-11-23 15:56 ` Steven Rostedt
2018-11-24 0:24 ` Tetsuo Handa
2018-11-26 4:34 ` Sergey Senozhatsky
2018-11-28 13:29 ` David Laight
2018-11-29 10:09 ` Tetsuo Handa
2018-11-30 16:01 ` Petr Mladek
2018-11-10 8:52 ` Tetsuo Handa
2018-11-23 12:52 ` Petr Mladek
2018-11-09 14:08 ` Linus Torvalds
2018-11-09 14:42 ` Steven Rostedt
2018-11-08 11:53 ` Petr Mladek
2018-11-08 12:44 ` Sergey Senozhatsky
2018-11-08 14:21 ` Sergey Senozhatsky
2018-11-09 9:54 ` Tetsuo Handa
2018-11-02 14:40 ` [PATCH v6 1/3] printk: Add line-buffered printk() API Matthew Wilcox
2018-11-03 1:55 ` Tetsuo Handa
2018-11-02 18:12 ` kbuild test robot
2018-11-06 14:35 ` Sergey Senozhatsky
2018-11-07 10:21 ` Petr Mladek
2018-11-07 12:54 ` Tetsuo Handa
2018-11-08 2:21 ` Sergey Senozhatsky
2018-11-08 11:24 ` Petr Mladek
2018-11-08 11:46 ` Tetsuo Handa
2018-11-08 12:30 ` Sergey Senozhatsky
2018-11-09 14:10 ` Petr Mladek
2018-11-12 7:59 ` Sergey Senozhatsky
2018-11-12 10:42 ` Tetsuo Handa
2018-11-17 10:14 ` Tetsuo Handa
2018-11-07 10:52 ` Tetsuo Handa
2018-11-07 11:01 ` David Laight
2018-11-07 12:00 ` Petr Mladek
2018-11-07 11:45 ` Petr Mladek
2018-11-08 2:30 ` Sergey Senozhatsky
2018-11-07 13:41 ` Petr Mladek
2018-11-07 14:06 ` Petr Mladek
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