Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755871AbZCVTCU (ORCPT ); Sun, 22 Mar 2009 15:02:20 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754871AbZCVTCI (ORCPT ); Sun, 22 Mar 2009 15:02:08 -0400 Received: from mail-fx0-f158.google.com ([209.85.220.158]:46311 "EHLO mail-fx0-f158.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754657AbZCVTCG (ORCPT ); Sun, 22 Mar 2009 15:02:06 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=date:from:to:cc:subject:message-id:references:mime-version :content-type:content-disposition:in-reply-to:user-agent; b=myCAzaJRhH96T7EHQTVBr/fUU6Kbv24sSahuOxPIm+d43Sk3DnF1soc2WgzcoS2Q45 vkG9kCIpJMON4QF5S8zMq5iwSrfm/8FuOfk4RVchG3hdJJCeLzNGHgYcVwsSfBSGxqDJ Q6cLqwWrHEGKqeiaEeP3v4KE/Iu6z5eKPQmX8= Date: Sun, 22 Mar 2009 20:01:59 +0100 From: Frederic Weisbecker To: Tom Zanussi Cc: linux-kernel , Ingo Molnar , Steven Rostedt Subject: Re: [PATCH 4/4] tracing: add per-subsystem filtering Message-ID: <20090322190158.GF6002@nowhere> References: <1237710677.7703.49.camel@charm-linux> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1237710677.7703.49.camel@charm-linux> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 8514 Lines: 306 On Sun, Mar 22, 2009 at 03:31:17AM -0500, Tom Zanussi wrote: > This patch adds per-subsystem filtering to the event tracing subsystem. > > It adds a 'filter' debugfs file to each subsystem directory. This file > can be written to to set filters; reading from it will display the > current set of filters set for that subsystem. > > Basically what it does is propagate the filter down to each event > contained in the subsystem. If a particular event doesn't have a field > with the name specified in the filter, it simply doesn't get set for > that event. You can verify whether or not the filter was set for a > particular event by looking at the filter file for that event. > > As with per-event filters, compound expressions are supported, echoing > '0' to the subsystem's filter file clears all filters in the subsystem, > etc. > > Signed-off-by: Tom Zanussi > > --- > kernel/trace/trace.h | 15 ++++++ > kernel/trace/trace_events.c | 86 +++++++++++++++++++++++++++++++++--- > kernel/trace/trace_events_filter.c | 80 +++++++++++++++++++++++++++++++++ > 3 files changed, 175 insertions(+), 6 deletions(-) > > diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h > index d9eb39e..f267723 100644 > --- a/kernel/trace/trace.h > +++ b/kernel/trace/trace.h > @@ -804,6 +804,18 @@ struct ftrace_event_call { > #endif > }; > > +struct event_subsystem { > + struct list_head list; > + const char *name; > + struct dentry *entry; > + struct filter_pred **preds; > +}; > + > +#define events_for_each(event) \ > + for (event = __start_ftrace_events; \ > + (unsigned long)event < (unsigned long)__stop_ftrace_events; \ > + event++) > + > #define MAX_FILTER_PRED 8 > > struct filter_pred; > @@ -832,6 +844,9 @@ extern int filter_add_pred(struct ftrace_event_call *call, > struct filter_pred *pred); > extern void filter_free_preds(struct ftrace_event_call *call); > extern int filter_match_preds(struct ftrace_event_call *call, void *rec); > +extern void filter_free_subsystem_preds(struct event_subsystem *system); > +extern int filter_add_subsystem_pred(struct event_subsystem *system, > + struct filter_pred *pred); > > void event_trace_printk(unsigned long ip, const char *fmt, ...); > extern struct ftrace_event_call __start_ftrace_events[]; > diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c > index 97470c4..97d4daa 100644 > --- a/kernel/trace/trace_events.c > +++ b/kernel/trace/trace_events.c > @@ -524,6 +524,71 @@ event_filter_write(struct file *filp, const char __user *ubuf, size_t cnt, > return cnt; > } > > +static ssize_t > +subsystem_filter_read(struct file *filp, char __user *ubuf, size_t cnt, > + loff_t *ppos) > +{ > + struct event_subsystem *system = filp->private_data; > + struct trace_seq *s; > + int r; > + > + if (*ppos) > + return 0; > + > + s = kmalloc(sizeof(*s), GFP_KERNEL); > + if (!s) > + return -ENOMEM; > + > + trace_seq_init(s); > + > + r = filter_print_preds(system->preds, s->buffer); > + r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, r); > + > + kfree(s); > + > + return r; > +} > + > +static ssize_t > +subsystem_filter_write(struct file *filp, const char __user *ubuf, size_t cnt, > + loff_t *ppos) > +{ > + struct event_subsystem *system = filp->private_data; > + char buf[64], *pbuf = buf; > + struct filter_pred *pred; > + int err; > + > + if (cnt >= sizeof(buf)) > + return -EINVAL; > + > + if (copy_from_user(&buf, ubuf, cnt)) > + return -EFAULT; > + > + pred = kzalloc(sizeof(*pred), GFP_KERNEL); > + if (!pred) > + return -ENOMEM; > + > + err = filter_parse(&pbuf, pred); > + if (err < 0) { > + filter_free_pred(pred); > + return err; > + } > + > + if (pred->clear) { > + filter_free_subsystem_preds(system); > + return cnt; > + } > + > + if (filter_add_subsystem_pred(system, pred)) { > + filter_free_pred(pred); > + return -EINVAL; > + } > + > + *ppos += cnt; > + > + return cnt; > +} > + > static const struct seq_operations show_event_seq_ops = { > .start = t_start, > .next = t_next, > @@ -575,6 +640,12 @@ static const struct file_operations ftrace_event_filter_fops = { > .write = event_filter_write, > }; > > +static const struct file_operations ftrace_subsystem_filter_fops = { > + .open = tracing_open_generic, > + .read = subsystem_filter_read, > + .write = subsystem_filter_write, > +}; > + > static struct dentry *event_trace_events_dir(void) > { > static struct dentry *d_tracer; > @@ -595,18 +666,13 @@ static struct dentry *event_trace_events_dir(void) > return d_events; > } > > -struct event_subsystem { > - struct list_head list; > - const char *name; > - struct dentry *entry; > -}; > - > static LIST_HEAD(event_subsystems); > > static struct dentry * > event_subsystem_dir(const char *name, struct dentry *d_events) > { > struct event_subsystem *system; > + struct dentry *entry; > > /* First see if we did not already create this dir */ > list_for_each_entry(system, &event_subsystems, list) { > @@ -633,6 +699,14 @@ event_subsystem_dir(const char *name, struct dentry *d_events) > system->name = name; > list_add(&system->list, &event_subsystems); > > + system->preds = NULL; > + > + entry = debugfs_create_file("filter", 0444, system->entry, system, Should be 0644. > + &ftrace_subsystem_filter_fops); > + if (!entry) > + pr_warning("Could not create debugfs " > + "'%s/filter' entry\n", name); > + > return system->entry; > } > > diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c > index 8e8c5fa..1ab20ce 100644 > --- a/kernel/trace/trace_events_filter.c > +++ b/kernel/trace/trace_events_filter.c > @@ -181,6 +181,27 @@ void filter_free_preds(struct ftrace_event_call *call) > } > } > > +void filter_free_subsystem_preds(struct event_subsystem *system) > +{ > + struct ftrace_event_call *call = __start_ftrace_events; > + int i; > + > + if (system->preds) { > + for (i = 0; i < MAX_FILTER_PRED; i++) > + filter_free_pred(system->preds[i]); > + kfree(system->preds); > + system->preds = NULL; > + } > + > + events_for_each(call) { > + if (!call->name || !call->regfunc) > + continue; > + > + if (!strcmp(call->system, system->name)) > + filter_free_preds(call); > + } > +} > + > static int __filter_add_pred(struct ftrace_event_call *call, > struct filter_pred *pred) > { > @@ -250,6 +271,65 @@ int filter_add_pred(struct ftrace_event_call *call, struct filter_pred *pred) > return __filter_add_pred(call, pred); > } > > +static struct filter_pred *copy_pred(struct filter_pred *pred) > +{ > + struct filter_pred *new_pred = kmalloc(sizeof(*pred), GFP_KERNEL); > + if (!new_pred) > + return NULL; > + > + memcpy(new_pred, pred, sizeof(*pred)); > + if (pred->str_val) { > + new_pred->str_val = kstrdup(pred->str_val, GFP_KERNEL); > + new_pred->field_name = kstrdup(pred->field_name, GFP_KERNEL); > + if (!new_pred->str_val) { > + kfree(new_pred); > + return NULL; > + } > + } > + > + return new_pred; > +} > + > +int filter_add_subsystem_pred(struct event_subsystem *system, > + struct filter_pred *pred) > +{ > + struct ftrace_event_call *call = __start_ftrace_events; > + struct filter_pred *event_pred; > + int i; > + > + if (system->preds && !pred->compound) > + filter_free_subsystem_preds(system); > + > + if (!system->preds) { > + system->preds = kzalloc(MAX_FILTER_PRED * sizeof(pred), > + GFP_KERNEL); > + if (!system->preds) > + return -ENOMEM; > + } > + > + for (i = 0; i < MAX_FILTER_PRED; i++) { > + if (!system->preds[i]) { > + system->preds[i] = pred; > + break; > + } > + if (i == MAX_FILTER_PRED - 1) > + return -EINVAL; Shouldn't it be i == MAX_FILTER_PRED ? > + } > + > + events_for_each(call) { > + if (!call->name || !call->regfunc) > + continue; > + > + if (!strcmp(call->system, system->name)) { > + event_pred = copy_pred(pred); > + if (event_pred) > + filter_add_pred(call, event_pred); > + } > + } > + > + return 0; > +} > + > int filter_parse(char **pbuf, struct filter_pred *pred) > { > char *tmp, *tok, *val_str = NULL; > -- > 1.5.6.3 > > > Looks good too. Acked-by: Frederic Weisbecker -- 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/