From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752388AbZL3GWf (ORCPT ); Wed, 30 Dec 2009 01:22:35 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751989AbZL3GWe (ORCPT ); Wed, 30 Dec 2009 01:22:34 -0500 Received: from cn.fujitsu.com ([222.73.24.84]:49805 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1751974AbZL3GWe (ORCPT ); Wed, 30 Dec 2009 01:22:34 -0500 Message-ID: <4B3AF19E.1010201@cn.fujitsu.com> Date: Wed, 30 Dec 2009 14:22:22 +0800 From: Li Zefan User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.1b3pre) Gecko/20090513 Fedora/3.0-2.3.beta2.fc11 Thunderbird/3.0b2 MIME-Version: 1.0 To: Frederic Weisbecker CC: Steven Rostedt , Ingo Molnar , "K.Prasad" , LKML Subject: [PATCH 1/4] ksym_tracer: Fix to make the tracer work 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 ksym tracer doesn't work: # echo tasklist_lock:rw- > ksym_trace_filter -bash: echo: write error: No such device It's because we pass to perf_event_create_kernel_counter() a cpu number which is not present. Signed-off-by: Li Zefan --- kernel/hw_breakpoint.c | 10 +++++++--- kernel/trace/trace_ksym.c | 1 - 2 files changed, 7 insertions(+), 4 deletions(-) diff --git a/kernel/hw_breakpoint.c b/kernel/hw_breakpoint.c index dbcbf6a..50dbd59 100644 --- a/kernel/hw_breakpoint.c +++ b/kernel/hw_breakpoint.c @@ -40,6 +40,7 @@ #include #include #include +#include #include #include @@ -388,7 +389,8 @@ register_wide_hw_breakpoint(struct perf_event_attr *attr, if (!cpu_events) return ERR_PTR(-ENOMEM); - for_each_possible_cpu(cpu) { + get_online_cpus(); + for_each_online_cpu(cpu) { pevent = per_cpu_ptr(cpu_events, cpu); bp = perf_event_create_kernel_counter(attr, cpu, -1, triggered); @@ -399,18 +401,20 @@ register_wide_hw_breakpoint(struct perf_event_attr *attr, goto fail; } } + put_online_cpus(); return cpu_events; fail: - for_each_possible_cpu(cpu) { + for_each_online_cpu(cpu) { pevent = per_cpu_ptr(cpu_events, cpu); if (IS_ERR(*pevent)) break; unregister_hw_breakpoint(*pevent); } + put_online_cpus(); + free_percpu(cpu_events); - /* return the error if any */ return ERR_PTR(err); } EXPORT_SYMBOL_GPL(register_wide_hw_breakpoint); diff --git a/kernel/trace/trace_ksym.c b/kernel/trace/trace_ksym.c index faf37fa..340b6ff 100644 --- a/kernel/trace/trace_ksym.c +++ b/kernel/trace/trace_ksym.c @@ -197,7 +197,6 @@ int process_new_ksym_entry(char *ksymname, int op, unsigned long addr) entry->attr.bp_addr = addr; entry->attr.bp_len = HW_BREAKPOINT_LEN_4; - ret = -EAGAIN; entry->ksym_hbp = register_wide_hw_breakpoint(&entry->attr, ksym_hbp_handler); -- 1.6.3