Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757042AbZINUre (ORCPT ); Mon, 14 Sep 2009 16:47:34 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756996AbZINUrc (ORCPT ); Mon, 14 Sep 2009 16:47:32 -0400 Received: from mx1.redhat.com ([209.132.183.28]:28432 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756975AbZINUra (ORCPT ); Mon, 14 Sep 2009 16:47:30 -0400 From: Masami Hiramatsu Subject: [PATCH tracing/kprobes 2/6] ftrace: Fix trace_add_event_call() to initialize list To: Frederic Weisbecker , Steven Rostedt , Ingo Molnar , lkml Cc: systemtap , DLE , Masami Hiramatsu , Jim Keniston , Ananth N Mavinakayanahalli , Andi Kleen , Christoph Hellwig , "Frank Ch. Eigler" , Frederic Weisbecker , "H. Peter Anvin" , Ingo Molnar , Jason Baron , "K.Prasad" , Lai Jiangshan , Li Zefan , Peter Zijlstra , Srikar Dronamraju , Steven Rostedt , Tom Zanussi Date: Mon, 14 Sep 2009 16:49:04 -0400 Message-ID: <20090914204904.18779.59422.stgit@dhcp-100-2-132.bos.redhat.com> In-Reply-To: <20090914204847.18779.69409.stgit@dhcp-100-2-132.bos.redhat.com> References: <20090914204847.18779.69409.stgit@dhcp-100-2-132.bos.redhat.com> User-Agent: StGIT/0.14.3 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3181 Lines: 90 Initialize event_call.list and handle failuer path in trace_add_event_call() for fixing below bug which occurred when I tried to add invalid event twice. Could not create debugfs 'kmalloc' directory Failed to register kprobe event: kmalloc Faild to register probe event(-1) ------------[ cut here ]------------ WARNING: at /home/mhiramat/ksrc/random-tracing/lib/list_debug.c:26 __list_add+0x27/0x5c() Hardware name: list_add corruption. next->prev should be prev (c07d78cc), but was 00001000. (next=d854236c). Modules linked in: sunrpc uinput virtio_net virtio_balloon i2c_piix4 pcspkr i2c_core virtio_blk virtio_pci virtio_ring virtio [last unloaded: scsi_wait_scan] Pid: 1394, comm: tee Not tainted 2.6.31-rc9 #51 Call Trace: [] warn_slowpath_common+0x65/0x7c [] ? __list_add+0x27/0x5c [] warn_slowpath_fmt+0x24/0x27 [] __list_add+0x27/0x5c [] list_add+0xa/0xc [] trace_add_event_call+0x60/0x97 [] command_trace_probe+0x42c/0x51b [] ? remove_wait_queue+0x22/0x27 [] ? __wake_up+0x32/0x3b [] probes_write+0xd4/0x10a [] ? probes_write+0x0/0x10a [] vfs_write+0x80/0xdf [] sys_write+0x3b/0x5d [] syscall_call+0x7/0xb ---[ end trace 2b962b5dc1fdc07d ]--- Signed-off-by: Masami Hiramatsu Cc: Jim Keniston Cc: Ananth N Mavinakayanahalli Cc: Andi Kleen Cc: Christoph Hellwig Cc: Frank Ch. Eigler Cc: Frederic Weisbecker Cc: H. Peter Anvin Cc: Ingo Molnar Cc: Jason Baron Cc: K.Prasad Cc: Lai Jiangshan Cc: Li Zefan Cc: Peter Zijlstra Cc: Srikar Dronamraju Cc: Steven Rostedt Cc: Tom Zanussi --- kernel/trace/trace_events.c | 6 +++++- 1 files changed, 5 insertions(+), 1 deletions(-) diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index ba34920..38e82a5 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -1009,10 +1009,14 @@ static int __trace_add_event_call(struct ftrace_event_call *call) if (!d_events) return -ENOENT; + INIT_LIST_HEAD(&call->list); list_add(&call->list, &ftrace_events); - return event_create_dir(call, d_events, &ftrace_event_id_fops, + ret = event_create_dir(call, d_events, &ftrace_event_id_fops, &ftrace_enable_fops, &ftrace_event_filter_fops, &ftrace_event_format_fops); + if (ret < 0) + list_del(&call->list); + return ret; } /* Add an additional event_call dynamically */ -- Masami Hiramatsu Software Engineer Hitachi Computer Products (America), Inc. Software Solutions Division e-mail: mhiramat@redhat.com -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/