diff options
| -rw-r--r-- | fs/pstore/ftrace.c | 46 |
1 files changed, 30 insertions, 16 deletions
diff --git a/fs/pstore/ftrace.c b/fs/pstore/ftrace.c index 5939595f0115..776cae20af4e 100644 --- a/fs/pstore/ftrace.c +++ b/fs/pstore/ftrace.c @@ -64,20 +64,12 @@ static struct ftrace_ops pstore_ftrace_ops __read_mostly = { static DEFINE_MUTEX(pstore_ftrace_lock); static bool pstore_ftrace_enabled; -static ssize_t pstore_ftrace_knob_write(struct file *f, const char __user *buf, - size_t count, loff_t *ppos) +static int pstore_set_ftrace_enabled(bool on) { - u8 on; ssize_t ret; - ret = kstrtou8_from_user(buf, count, 2, &on); - if (ret) - return ret; - - mutex_lock(&pstore_ftrace_lock); - - if (!on ^ pstore_ftrace_enabled) - goto out; + if (on == pstore_ftrace_enabled) + return 0; if (on) { ftrace_ops_set_global_filter(&pstore_ftrace_ops); @@ -89,15 +81,30 @@ static ssize_t pstore_ftrace_knob_write(struct file *f, const char __user *buf, if (ret) { pr_err("%s: unable to %sregister ftrace ops: %zd\n", __func__, on ? "" : "un", ret); - goto err; + } else { + pstore_ftrace_enabled = on; } - pstore_ftrace_enabled = on; -out: - ret = count; -err: + return ret; +} + +static ssize_t pstore_ftrace_knob_write(struct file *f, const char __user *buf, + size_t count, loff_t *ppos) +{ + u8 on; + ssize_t ret; + + ret = kstrtou8_from_user(buf, count, 2, &on); + if (ret) + return ret; + + mutex_lock(&pstore_ftrace_lock); + ret = pstore_set_ftrace_enabled(on); mutex_unlock(&pstore_ftrace_lock); + if (ret == 0) + ret = count; + return ret; } @@ -117,6 +124,11 @@ static const struct file_operations pstore_knob_fops = { static struct dentry *pstore_ftrace_dir; +static bool record_ftrace; +module_param(record_ftrace, bool, 0400); +MODULE_PARM_DESC(record_ftrace, + "enable ftrace recording immediately (default: off)"); + void pstore_register_ftrace(void) { if (!psinfo->write) @@ -124,6 +136,8 @@ void pstore_register_ftrace(void) pstore_ftrace_dir = debugfs_create_dir("pstore", NULL); + pstore_set_ftrace_enabled(record_ftrace); + debugfs_create_file("record_ftrace", 0600, pstore_ftrace_dir, NULL, &pstore_knob_fops); } |