]> pilppa.com Git - linux-2.6-omap-h63xx.git/commitdiff
tracing: add tracer dependent options to options directory
authorSteven Rostedt <srostedt@redhat.com>
Fri, 27 Feb 2009 04:43:05 +0000 (23:43 -0500)
committerSteven Rostedt <srostedt@redhat.com>
Fri, 27 Feb 2009 04:43:05 +0000 (23:43 -0500)
This patch adds the tracer dependent options dynamically to the
options directory when the tracer is activated. These options are
removed when the tracer is deactivated.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
kernel/trace/trace.c

index 40e983ed994f5338a1a7fef1eb8bff3cf2698910..485c6e7f4465b6e6464642f76257644edd3ca58a 100644 (file)
@@ -2275,8 +2275,17 @@ int tracer_init(struct tracer *t, struct trace_array *tr)
        return t->init(tr);
 }
 
+struct trace_option_dentry;
+
+static struct trace_option_dentry *
+create_trace_option_files(struct tracer *tracer);
+
+static void
+destroy_trace_option_files(struct trace_option_dentry *topts);
+
 static int tracing_set_tracer(const char *buf)
 {
+       static struct trace_option_dentry *topts;
        struct trace_array *tr = &global_trace;
        struct tracer *t;
        int ret = 0;
@@ -2297,7 +2306,12 @@ static int tracing_set_tracer(const char *buf)
        if (current_trace && current_trace->reset)
                current_trace->reset(tr);
 
+       destroy_trace_option_files(topts);
+
        current_trace = t;
+
+       topts = create_trace_option_files(current_trace);
+
        if (t->init) {
                ret = tracer_init(t, tr);
                if (ret)
@@ -3093,6 +3107,95 @@ static void tracing_init_debugfs_percpu(long cpu)
 #include "trace_selftest.c"
 #endif
 
+struct trace_option_dentry {
+       struct tracer_opt               *opt;
+       struct tracer_flags             *flags;
+       struct dentry                   *entry;
+};
+
+static ssize_t
+trace_options_read(struct file *filp, char __user *ubuf, size_t cnt,
+                       loff_t *ppos)
+{
+       struct trace_option_dentry *topt = filp->private_data;
+       char *buf;
+
+       if (topt->flags->val & topt->opt->bit)
+               buf = "1\n";
+       else
+               buf = "0\n";
+
+       return simple_read_from_buffer(ubuf, cnt, ppos, buf, 2);
+}
+
+static ssize_t
+trace_options_write(struct file *filp, const char __user *ubuf, size_t cnt,
+                        loff_t *ppos)
+{
+       struct trace_option_dentry *topt = filp->private_data;
+       unsigned long val;
+       char buf[64];
+       int ret;
+
+       if (cnt >= sizeof(buf))
+               return -EINVAL;
+
+       if (copy_from_user(&buf, ubuf, cnt))
+               return -EFAULT;
+
+       buf[cnt] = 0;
+
+       ret = strict_strtoul(buf, 10, &val);
+       if (ret < 0)
+               return ret;
+
+       ret = 0;
+       switch (val) {
+       case 0:
+               /* do nothing if already cleared */
+               if (!(topt->flags->val & topt->opt->bit))
+                       break;
+
+               mutex_lock(&trace_types_lock);
+               if (current_trace->set_flag)
+                       ret = current_trace->set_flag(topt->flags->val,
+                                                     topt->opt->bit, 0);
+               mutex_unlock(&trace_types_lock);
+               if (ret)
+                       return ret;
+               topt->flags->val &= ~topt->opt->bit;
+               break;
+       case 1:
+               /* do nothing if already set */
+               if (topt->flags->val & topt->opt->bit)
+                       break;
+
+               mutex_lock(&trace_types_lock);
+               if (current_trace->set_flag)
+                       ret = current_trace->set_flag(topt->flags->val,
+                                                     topt->opt->bit, 1);
+               mutex_unlock(&trace_types_lock);
+               if (ret)
+                       return ret;
+               topt->flags->val |= topt->opt->bit;
+               break;
+
+       default:
+               return -EINVAL;
+       }
+
+       *ppos += cnt;
+
+       return cnt;
+}
+
+
+static const struct file_operations trace_options_fops = {
+       .open = tracing_open_generic,
+       .read = trace_options_read,
+       .write = trace_options_write,
+};
+
 static ssize_t
 trace_options_core_read(struct file *filp, char __user *ubuf, size_t cnt,
                        loff_t *ppos)
@@ -3146,7 +3249,6 @@ trace_options_core_write(struct file *filp, const char __user *ubuf, size_t cnt,
        return cnt;
 }
 
-
 static const struct file_operations trace_options_core_fops = {
        .open = tracing_open_generic,
        .read = trace_options_core_read,
@@ -3174,6 +3276,76 @@ static struct dentry *trace_options_init_dentry(void)
        return t_options;
 }
 
+static void
+create_trace_option_file(struct trace_option_dentry *topt,
+                        struct tracer_flags *flags,
+                        struct tracer_opt *opt)
+{
+       struct dentry *t_options;
+       struct dentry *entry;
+
+       t_options = trace_options_init_dentry();
+       if (!t_options)
+               return;
+
+       topt->flags = flags;
+       topt->opt = opt;
+
+       entry = debugfs_create_file(opt->name, 0644, t_options, topt,
+                                   &trace_options_fops);
+
+       topt->entry = entry;
+
+}
+
+static struct trace_option_dentry *
+create_trace_option_files(struct tracer *tracer)
+{
+       struct trace_option_dentry *topts;
+       struct tracer_flags *flags;
+       struct tracer_opt *opts;
+       int cnt;
+
+       if (!tracer)
+               return NULL;
+
+       flags = tracer->flags;
+
+       if (!flags || !flags->opts)
+               return NULL;
+
+       opts = flags->opts;
+
+       for (cnt = 0; opts[cnt].name; cnt++)
+               ;
+
+       topts = kzalloc(sizeof(*topts) * (cnt + 1), GFP_KERNEL);
+       if (!topts)
+               return NULL;
+
+       for (cnt = 0; opts[cnt].name; cnt++)
+               create_trace_option_file(&topts[cnt], flags,
+                                        &opts[cnt]);
+
+       return topts;
+}
+
+static void
+destroy_trace_option_files(struct trace_option_dentry *topts)
+{
+       int cnt;
+
+       if (!topts)
+               return;
+
+       for (cnt = 0; topts[cnt].opt; cnt++) {
+               if (topts[cnt].entry)
+                       debugfs_remove(topts[cnt].entry);
+       }
+
+       kfree(topts);
+}
+
 static struct dentry *
 create_trace_option_core_file(const char *option, long index)
 {