Messages in this thread | | | Date | Mon, 23 Mar 2009 14:24:21 -0400 (EDT) | From | Steven Rostedt <> | Subject | Re: [PATCH 4/4] tracing: add per-subsystem filtering |
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On Sun, 22 Mar 2009, Tom Zanussi wrote: > > +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;
Again, trace_seq is not used, might as well use your own buffer.
> + 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);
is "system" correct here?
> + 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, > + &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);
Shouldn't there be a check for field_name too?
-- Steve
> + return NULL; > + } > + } > + > + return new_pred; > +} > +
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