From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932183Ab3CDR1U (ORCPT ); Mon, 4 Mar 2013 12:27:20 -0500 Received: from hrndva-omtalb.mail.rr.com ([71.74.56.122]:24050 "EHLO hrndva-omtalb.mail.rr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758398Ab3CDR0S (ORCPT ); Mon, 4 Mar 2013 12:26:18 -0500 X-Authority-Analysis: v=2.0 cv=BZhaI8R2 c=1 sm=0 a=rXTBtCOcEpjy1lPqhTCpEQ==:17 a=mNMOxpOpBa8A:10 a=Ciwy3NGCPMMA:10 a=UgPFicLonLYA:10 a=5SG0PmZfjMsA:10 a=bbbx4UPp9XUA:10 a=meVymXHHAAAA:8 a=QgIG4jImTz4A:10 a=20KFwNOVAAAA:8 a=QyXUC8HyAAAA:8 a=hQgOcaguxhxKgGOGdVMA:9 a=jEp0ucaQiEUA:10 a=dGJ0OcVc7YAA:10 a=jeBq3FmKZ4MA:10 a=9XJ83icqKTB-iqIN:21 a=snrVA3mKqSYbsE1x:21 a=rXTBtCOcEpjy1lPqhTCpEQ==:117 X-Cloudmark-Score: 0 X-Authenticated-User: X-Originating-IP: 74.67.115.198 Message-Id: <20130304172616.025880747@goodmis.org> User-Agent: quilt/0.60-1 Date: Mon, 04 Mar 2013 12:20:10 -0500 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Ingo Molnar , Andrew Morton , Frederic Weisbecker , Fengguang Wu Subject: [for-next][PATCH 5/6] tracing: Fix trace events build without modules References: <20130304172005.362537932@goodmis.org> Content-Disposition: inline; filename=0005-tracing-Fix-trace-events-build-without-modules.patch Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: "Steven Rostedt (Red Hat)" The new multi-buffers added a descriptor that kept track of module events, and the directories they use, with struct ftace_module_file_ops. This is used to add a ref count to keep modules from unloading while their files are being accessed. As the descriptor is only needed when CONFIG_MODULES is enabled, it is only declared when the config is enabled. But that struct is dereferenced in a few areas outside the #ifdef CONFIG_MODULES. By adding some helper routines and moving code around a little, events can be compiled again without modules. Reported-by: Fengguang Wu Signed-off-by: Steven Rostedt --- kernel/trace/trace_events.c | 55 ++++++++++++++++++++++++++++--------------- 1 file changed, 36 insertions(+), 19 deletions(-) diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index 63b4bdf..0f1307a 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -1546,9 +1546,18 @@ struct ftrace_module_file_ops { struct file_operations filter; }; -static struct ftrace_module_file_ops *find_ftrace_file_ops(struct module *mod) +static struct ftrace_module_file_ops * +find_ftrace_file_ops(struct ftrace_module_file_ops *file_ops, struct module *mod) { - struct ftrace_module_file_ops *file_ops; + /* + * As event_calls are added in groups by module, + * when we find one file_ops, we don't need to search for + * each call in that module, as the rest should be the + * same. Only search for a new one if the last one did + * not match. + */ + if (file_ops && mod == file_ops->mod) + return file_ops; list_for_each_entry(file_ops, &ftrace_module_file_list, list) { if (file_ops->mod == mod) @@ -1664,16 +1673,35 @@ static int trace_module_notify(struct notifier_block *self, return 0; } + +static int +__trace_add_new_mod_event(struct ftrace_event_call *call, + struct trace_array *tr, + struct ftrace_module_file_ops *file_ops) +{ + return __trace_add_new_event(call, tr, + &file_ops->id, &file_ops->enable, + &file_ops->filter, &file_ops->format); +} + #else -static struct ftrace_module_file_ops *find_ftrace_file_ops(struct module *mod) +static inline struct ftrace_module_file_ops * +find_ftrace_file_ops(struct ftrace_module_file_ops *file_ops, struct module *mod) { return NULL; } -static int trace_module_notify(struct notifier_block *self, - unsigned long val, void *data) +static inline int trace_module_notify(struct notifier_block *self, + unsigned long val, void *data) { return 0; } +static inline int +__trace_add_new_mod_event(struct ftrace_event_call *call, + struct trace_array *tr, + struct ftrace_module_file_ops *file_ops) +{ + return -ENODEV; +} #endif /* CONFIG_MODULES */ /* Create a new event directory structure for a trace directory. */ @@ -1692,20 +1720,11 @@ __trace_add_event_dirs(struct trace_array *tr) * want the module to disappear when reading one * of these files). The file_ops keep account of * the module ref count. - * - * As event_calls are added in groups by module, - * when we find one file_ops, we don't need to search for - * each call in that module, as the rest should be the - * same. Only search for a new one if the last one did - * not match. */ - if (!file_ops || call->mod != file_ops->mod) - file_ops = find_ftrace_file_ops(call->mod); + file_ops = find_ftrace_file_ops(file_ops, call->mod); if (!file_ops) continue; /* Warn? */ - ret = __trace_add_new_event(call, tr, - &file_ops->id, &file_ops->enable, - &file_ops->filter, &file_ops->format); + ret = __trace_add_new_mod_event(call, tr, file_ops); if (ret < 0) pr_warning("Could not create directory for event %s\n", call->name); @@ -1794,9 +1813,7 @@ __add_event_to_tracers(struct ftrace_event_call *call, list_for_each_entry(tr, &ftrace_trace_arrays, list) { if (file_ops) - __trace_add_new_event(call, tr, - &file_ops->id, &file_ops->enable, - &file_ops->filter, &file_ops->format); + __trace_add_new_mod_event(call, tr, file_ops); else __trace_add_new_event(call, tr, &ftrace_event_id_fops, -- 1.7.10.4