From: Sasha Levin <sasha.levin@oracle.com>
To: Steven Rostedt <rostedt@goodmis.org>, linux-kernel@vger.kernel.org
Cc: Andrew Morton <akpm@linux-foundation.org>,
Alexander Lam <azl@google.com>
Subject: Re: [for-next][PATCH 14/14] tracing: Get trace_array ref counts when accessing trace files
Date: Sat, 05 Apr 2014 10:59:10 -0400 [thread overview]
Message-ID: <53401A3E.2090302@oracle.com> (raw)
In-Reply-To: <20130702202427.455930200@goodmis.org>
On 07/02/2013 04:22 PM, Steven Rostedt wrote:
> From: "Steven Rostedt (Red Hat)" <rostedt@goodmis.org>
>
> When a trace file is opened that may access a trace array, it must
> increment its ref count to prevent it from being deleted.
>
> Cc: stable@vger.kernel.org # 3.10
> Reported-by: Alexander Lam <azl@google.com>
> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Hi Steven,
This patch seems to cause the following lockdep warning:
[ 5644.288019] ======================================================
[ 5644.288771] [ INFO: possible circular locking dependency detected ]
[ 5644.289657] 3.14.0-next-20140403-sasha-00019-g7474aa9-dirty #376 Not tainted
[ 5644.290568] -------------------------------------------------------
[ 5644.290783] trinity-c17/19105 is trying to acquire lock:
[ 5644.290783] (trace_types_lock){+.+.+.}, at: trace_array_get (kernel/trace/trace.c:225)
[ 5644.290783]
[ 5644.290783] but task is already holding lock:
[ 5644.290783] (&sig->cred_guard_mutex){+.+.+.}, at: prepare_bprm_creds (fs/exec.c:1165)
[ 5644.290783]
[ 5644.290783] which lock already depends on the new lock.
[ 5644.290783]
[ 5644.290783]
[ 5644.290783] the existing dependency chain (in reverse order) is:
[ 5644.290783]
-> #2 (&sig->cred_guard_mutex){+.+.+.}:
[ 5644.290783] lock_acquire (arch/x86/include/asm/current.h:14 kernel/locking/lockdep.c:3602)
[ 5644.290783] mutex_lock_interruptible_nested (kernel/locking/mutex.c:486 kernel/locking/mutex.c:616)
[ 5644.290783] proc_pid_attr_write (fs/proc/base.c:2250)
[ 5644.290783] __kernel_write (fs/read_write.c:457)
[ 5644.290783] write_pipe_buf (fs/splice.c:1072)
[ 5644.290783] splice_from_pipe_feed (fs/splice.c:834)
[ 5644.290783] __splice_from_pipe (fs/splice.c:955)
[ 5644.290783] splice_from_pipe (fs/splice.c:990)
[ 5644.290783] default_file_splice_write (fs/splice.c:1084)
[ 5644.290783] SyS_splice (include/linux/fs.h:2333 fs/splice.c:1391 fs/splice.c:1764 fs/splice.c:1749)
[ 5644.290783] tracesys (arch/x86/kernel/entry_64.S:749)
[ 5644.290783]
-> #1 (&pipe->mutex/1){+.+.+.}:
[ 5644.290783] lock_acquire (arch/x86/include/asm/current.h:14 kernel/locking/lockdep.c:3602)
[ 5644.290783] mutex_lock_nested (kernel/locking/mutex.c:486 kernel/locking/mutex.c:587)
[ 5644.290783] pipe_lock_nested (fs/pipe.c:61)
[ 5644.290783] pipe_lock (fs/pipe.c:69)
[ 5644.290783] splice_to_pipe (include/linux/wait.h:103 fs/splice.c:247)
[ 5644.290783] tracing_buffers_splice_read (kernel/trace/trace.c:5423)
[ 5644.290783] do_splice_to (fs/splice.c:1151)
[ 5644.290783] SyS_splice (fs/splice.c:1416 fs/splice.c:1764 fs/splice.c:1749)
[ 5644.290783] ia32_sysret (arch/x86/ia32/ia32entry.S:430)
[ 5644.290783]
-> #0 (trace_types_lock){+.+.+.}:
[ 5644.290783] __lock_acquire (kernel/locking/lockdep.c:1840 kernel/locking/lockdep.c:1945 kernel/locking/lockdep.c:2131 kernel/locking/lockdep.c:3182)
[ 5644.290783] lock_acquire (arch/x86/include/asm/current.h:14 kernel/locking/lockdep.c:3602)
[ 5644.290783] mutex_lock_nested (kernel/locking/mutex.c:486 kernel/locking/mutex.c:587)
[ 5644.290783] trace_array_get (kernel/trace/trace.c:225)
[ 5644.290783] tracing_open_generic_tr (kernel/trace/trace.c:3053)
[ 5644.290783] do_dentry_open (fs/open.c:753)
[ 5644.290783] finish_open (fs/open.c:818)
[ 5644.290783] do_last (fs/namei.c:3040)
[ 5644.290783] path_openat (fs/namei.c:3182)
[ 5644.290783] do_filp_open (fs/namei.c:3231)
[ 5644.290783] do_open_exec (fs/exec.c:766)
[ 5644.290783] do_execve_common.isra.19 (fs/exec.c:1491)
[ 5644.290783] compat_SyS_execve (fs/exec.c:1627)
[ 5644.290783] ia32_ptregs_common (arch/x86/ia32/ia32entry.S:495)
[ 5644.290783]
[ 5644.290783] other info that might help us debug this:
[ 5644.290783]
[ 5644.290783] Chain exists of:
trace_types_lock --> &pipe->mutex/1 --> &sig->cred_guard_mutex
[ 5644.290783] Possible unsafe locking scenario:
[ 5644.290783]
[ 5644.290783] CPU0 CPU1
[ 5644.290783] ---- ----
[ 5644.290783] lock(&sig->cred_guard_mutex);
[ 5644.290783] lock(&pipe->mutex/1);
[ 5644.290783] lock(&sig->cred_guard_mutex);
[ 5644.290783] lock(trace_types_lock);
[ 5644.290783]
[ 5644.290783] *** DEADLOCK ***
[ 5644.290783]
[ 5644.290783] 1 lock held by trinity-c17/19105:
[ 5644.290783] #0: (&sig->cred_guard_mutex){+.+.+.}, at: prepare_bprm_creds (fs/exec.c:1165)
[ 5644.290783]
[ 5644.290783] stack backtrace:
[ 5644.290783] CPU: 10 PID: 19105 Comm: trinity-c17 Not tainted 3.14.0-next-20140403-sasha-00019-g7474aa9-dirty #376
[ 5644.290783] ffffffffb4a1a1e0 ffff88071a7738f8 ffffffffb14bfb2f 0000000000000000
[ 5644.290783] ffffffffb49a9dd0 ffff88071a773948 ffffffffb14b2527 0000000000000001
[ 5644.290783] ffff88071a7739d8 ffff88071a773948 ffff8805d98cbcf0 ffff8805d98cbd28
[ 5644.290783] Call Trace:
[ 5644.290783] dump_stack (lib/dump_stack.c:52)
[ 5644.290783] print_circular_bug (kernel/locking/lockdep.c:1214)
[ 5644.290783] __lock_acquire (kernel/locking/lockdep.c:1840 kernel/locking/lockdep.c:1945 kernel/locking/lockdep.c:2131 kernel/locking/lockdep.c:3182)
[ 5644.290783] ? _raw_spin_unlock_irqrestore (arch/x86/include/asm/paravirt.h:809 include/linux/spinlock_api_smp.h:160 kernel/locking/spinlock.c:191)
[ 5644.290783] ? preempt_count_sub (kernel/sched/core.c:2527)
[ 5644.290783] ? __slab_free (mm/slub.c:2598)
[ 5644.290783] lock_acquire (arch/x86/include/asm/current.h:14 kernel/locking/lockdep.c:3602)
[ 5644.290783] ? trace_array_get (kernel/trace/trace.c:225)
[ 5644.290783] mutex_lock_nested (kernel/locking/mutex.c:486 kernel/locking/mutex.c:587)
[ 5644.290783] ? trace_array_get (kernel/trace/trace.c:225)
[ 5644.290783] ? locks_free_lock (fs/locks.c:244)
[ 5644.290783] ? trace_array_get (kernel/trace/trace.c:225)
[ 5644.290783] ? preempt_count_sub (kernel/sched/core.c:2527)
[ 5644.290783] trace_array_get (kernel/trace/trace.c:225)
[ 5644.290783] tracing_open_generic_tr (kernel/trace/trace.c:3053)
[ 5644.290783] do_dentry_open (fs/open.c:753)
[ 5644.290783] ? tracing_open_pipe (kernel/trace/trace.c:3047)
[ 5644.290783] finish_open (fs/open.c:818)
[ 5644.290783] do_last (fs/namei.c:3040)
[ 5644.290783] ? link_path_walk (fs/namei.c:1473 fs/namei.c:1744)
[ 5644.290783] ? __this_cpu_preempt_check (lib/smp_processor_id.c:63)
[ 5644.290783] ? trace_hardirqs_on_caller (kernel/locking/lockdep.c:2557 kernel/locking/lockdep.c:2599)
[ 5644.290783] path_openat (fs/namei.c:3182)
[ 5644.290783] ? __lock_acquire (kernel/locking/lockdep.c:3189)
[ 5644.290783] do_filp_open (fs/namei.c:3231)
[ 5644.290783] ? put_lock_stats.isra.12 (arch/x86/include/asm/preempt.h:98 kernel/locking/lockdep.c:254)
[ 5644.290783] ? do_execve_common.isra.19 (fs/exec.c:1489)
[ 5644.290783] ? get_parent_ip (kernel/sched/core.c:2472)
[ 5644.290783] do_open_exec (fs/exec.c:766)
[ 5644.290783] do_execve_common.isra.19 (fs/exec.c:1491)
[ 5644.290783] ? do_execve_common.isra.19 (include/linux/spinlock.h:303 fs/exec.c:1258 fs/exec.c:1486)
[ 5644.290783] compat_SyS_execve (fs/exec.c:1627)
[ 5644.290783] ia32_ptregs_common (arch/x86/ia32/ia32entry.S:495)
Thanks,
Sasha
next prev parent reply other threads:[~2014-04-05 14:59 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-07-02 20:22 [for-next][PATCH 00/14] tracing: updates and fixes for 3.10 Steven Rostedt
2013-07-02 20:22 ` [for-next][PATCH 01/14] tracing: Failed to create system directory Steven Rostedt
2013-07-02 20:22 ` [for-next][PATCH 02/14] tracing/kprobes: Avoid perf_trace_buf_*() if ->perf_events is empty Steven Rostedt
2013-07-02 20:22 ` [for-next][PATCH 03/14] tracing/kprobes: Kill probe_enable_lock Steven Rostedt
2013-07-02 20:22 ` [for-next][PATCH 04/14] tracing: Simplify code for showing of soft disabled flag Steven Rostedt
2013-07-02 20:22 ` [for-next][PATCH 05/14] tracing: Add missing syscall_metadata comment Steven Rostedt
2013-07-02 20:22 ` [for-next][PATCH 06/14] tracing: Fix disabling of soft disable Steven Rostedt
2013-07-02 20:22 ` [for-next][PATCH 07/14] tracing/kprobes: Turn trace_probe->files into list_head Steven Rostedt
2013-07-02 20:22 ` [for-next][PATCH 08/14] tracing: Use flag buffer_disabled for irqsoff tracer Steven Rostedt
2013-07-02 20:22 ` [for-next][PATCH 09/14] tracing/kprobes: Dont pass addr=ip to perf_trace_buf_submit() Steven Rostedt
2013-07-02 20:22 ` [for-next][PATCH 10/14] ftrace: Do not run selftest if command line parameter is set Steven Rostedt
2013-07-02 20:22 ` [for-next][PATCH 11/14] tracing: Make trace_marker use the correct per-instance buffer Steven Rostedt
2013-07-02 20:22 ` [for-next][PATCH 12/14] tracing: Protect ftrace_trace_arrays list in trace_events.c Steven Rostedt
2013-07-02 20:22 ` [for-next][PATCH 13/14] tracing: Add trace_array_get/put() to handle instance refs better Steven Rostedt
2013-07-02 20:22 ` [for-next][PATCH 14/14] tracing: Get trace_array ref counts when accessing trace files Steven Rostedt
2014-04-05 14:59 ` Sasha Levin [this message]
2014-04-05 18:33 ` Steven Rostedt
2014-04-05 20:03 ` Sasha Levin
2014-04-08 15:42 ` Steven Rostedt
2014-04-08 16:06 ` Sasha Levin
2014-04-05 18:43 ` Steven Rostedt
2014-04-08 16:36 ` Steven Rostedt
2014-04-08 16:52 ` Sasha Levin
2014-04-08 17:06 ` Steven Rostedt
2014-04-08 17:11 ` Sasha Levin
2014-04-08 17:32 ` Steven Rostedt
2014-04-10 13:33 ` Steven Rostedt
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