aboutsummaryrefslogtreecommitdiff
path: root/kernel
diff options
context:
space:
mode:
authorSteven Rostedt <srostedt@redhat.com>2009-02-14 00:40:25 -0500
committerSteven Rostedt <srostedt@redhat.com>2009-02-16 17:06:02 -0500
commitf6180773d90595650e11de0118bb112018290915 (patch)
treeccf8642d7ac584f73e7820fae64fc4daf4546f6b /kernel
parente68746a271eb3393a2183840be9e903caddf765b (diff)
ftrace: add command interface for function selection
Allow for other tracers to add their own commands for function selection. This interface gives a trace the ability to name a command for function selection. Right now it is pretty limited in what it offers, but this is a building step for more features. The :mod: command is converted to this interface and also serves as a template for other implementations. Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/trace/ftrace.c106
1 files changed, 95 insertions, 11 deletions
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 340f88b68d9..45a44c40256 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -1239,9 +1239,93 @@ static void ftrace_match_module_records(char *buff, char *mod, int enable)
spin_unlock(&ftrace_lock);
}
+/*
+ * We register the module command as a template to show others how
+ * to register the a command as well.
+ */
+
+static int
+ftrace_mod_callback(char *func, char *cmd, char *param, int enable)
+{
+ char *mod;
+
+ /*
+ * cmd == 'mod' because we only registered this func
+ * for the 'mod' ftrace_func_command.
+ * But if you register one func with multiple commands,
+ * you can tell which command was used by the cmd
+ * parameter.
+ */
+
+ /* we must have a module name */
+ if (!param)
+ return -EINVAL;
+
+ mod = strsep(&param, ":");
+ if (!strlen(mod))
+ return -EINVAL;
+
+ ftrace_match_module_records(func, mod, enable);
+ return 0;
+}
+
+static struct ftrace_func_command ftrace_mod_cmd = {
+ .name = "mod",
+ .func = ftrace_mod_callback,
+};
+
+static int __init ftrace_mod_cmd_init(void)
+{
+ return register_ftrace_command(&ftrace_mod_cmd);
+}
+device_initcall(ftrace_mod_cmd_init);
+
+static LIST_HEAD(ftrace_commands);
+static DEFINE_MUTEX(ftrace_cmd_mutex);
+
+int register_ftrace_command(struct ftrace_func_command *cmd)
+{
+ struct ftrace_func_command *p;
+ int ret = 0;
+
+ mutex_lock(&ftrace_cmd_mutex);
+ list_for_each_entry(p, &ftrace_commands, list) {
+ if (strcmp(cmd->name, p->name) == 0) {
+ ret = -EBUSY;
+ goto out_unlock;
+ }
+ }
+ list_add(&cmd->list, &ftrace_commands);
+ out_unlock:
+ mutex_unlock(&ftrace_cmd_mutex);
+
+ return ret;
+}
+
+int unregister_ftrace_command(struct ftrace_func_command *cmd)
+{
+ struct ftrace_func_command *p, *n;
+ int ret = -ENODEV;
+
+ mutex_lock(&ftrace_cmd_mutex);
+ list_for_each_entry_safe(p, n, &ftrace_commands, list) {
+ if (strcmp(cmd->name, p->name) == 0) {
+ ret = 0;
+ list_del_init(&p->list);
+ goto out_unlock;
+ }
+ }
+ out_unlock:
+ mutex_unlock(&ftrace_cmd_mutex);
+
+ return ret;
+}
+
static int ftrace_process_regex(char *buff, int len, int enable)
{
- char *func, *mod, *command, *next = buff;
+ struct ftrace_func_command *p;
+ char *func, *command, *next = buff;
+ int ret = -EINVAL;
func = strsep(&next, ":");
@@ -1250,21 +1334,21 @@ static int ftrace_process_regex(char *buff, int len, int enable)
return 0;
}
- /* command fonud */
+ /* command found */
command = strsep(&next, ":");
- if (strcmp(command, "mod") == 0) {
- /* only match modules */
- if (!next)
- return -EINVAL;
-
- mod = strsep(&next, ":");
- ftrace_match_module_records(func, mod, enable);
- return 0;
+ mutex_lock(&ftrace_cmd_mutex);
+ list_for_each_entry(p, &ftrace_commands, list) {
+ if (strcmp(p->name, command) == 0) {
+ ret = p->func(func, command, next, enable);
+ goto out_unlock;
+ }
}
+ out_unlock:
+ mutex_unlock(&ftrace_cmd_mutex);
- return -EINVAL;
+ return ret;
}
static ssize_t