diff options
Diffstat (limited to 'kernel/trace/ftrace.c')
| -rw-r--r-- | kernel/trace/ftrace.c | 142 |
1 files changed, 136 insertions, 6 deletions
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 9e5841dc14b5..1867edec6269 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -1293,6 +1293,28 @@ static void ftrace_hash_clear(struct ftrace_hash *hash) FTRACE_WARN_ON(hash->count); } +static void free_ftrace_mod(struct ftrace_mod_load *ftrace_mod) +{ + list_del(&ftrace_mod->list); + kfree(ftrace_mod->module); + kfree(ftrace_mod->func); + kfree(ftrace_mod); +} + +static void clear_ftrace_mod_list(struct list_head *head) +{ + struct ftrace_mod_load *p, *n; + + /* stack tracer isn't supported yet */ + if (!head) + return; + + mutex_lock(&ftrace_lock); + list_for_each_entry_safe(p, n, head, list) + free_ftrace_mod(p); + mutex_unlock(&ftrace_lock); +} + static void free_ftrace_hash(struct ftrace_hash *hash) { if (!hash || hash == EMPTY_HASH) @@ -1346,6 +1368,35 @@ static struct ftrace_hash *alloc_ftrace_hash(int size_bits) return hash; } + +static int ftrace_add_mod(struct trace_array *tr, + const char *func, const char *module, + int enable) +{ + struct ftrace_mod_load *ftrace_mod; + struct list_head *mod_head = enable ? &tr->mod_trace : &tr->mod_notrace; + + ftrace_mod = kzalloc(sizeof(*ftrace_mod), GFP_KERNEL); + if (!ftrace_mod) + return -ENOMEM; + + ftrace_mod->func = kstrdup(func, GFP_KERNEL); + ftrace_mod->module = kstrdup(module, GFP_KERNEL); + ftrace_mod->enable = enable; + + if (!ftrace_mod->func || !ftrace_mod->module) + goto out_free; + + list_add(&ftrace_mod->list, mod_head); + + return 0; + + out_free: + free_ftrace_mod(ftrace_mod); + + return -ENOMEM; +} + static struct ftrace_hash * alloc_and_copy_ftrace_hash(int size_bits, struct ftrace_hash *hash) { @@ -3457,6 +3508,8 @@ ftrace_regex_open(struct ftrace_ops *ops, int flag, { struct ftrace_iterator *iter; struct ftrace_hash *hash; + struct list_head *mod_head; + struct trace_array *tr = ops->private; int ret = 0; ftrace_ops_init(ops); @@ -3478,18 +3531,23 @@ ftrace_regex_open(struct ftrace_ops *ops, int flag, mutex_lock(&ops->func_hash->regex_lock); - if (flag & FTRACE_ITER_NOTRACE) + if (flag & FTRACE_ITER_NOTRACE) { hash = ops->func_hash->notrace_hash; - else + mod_head = tr ? &tr->mod_trace : NULL; + } else { hash = ops->func_hash->filter_hash; + mod_head = tr ? &tr->mod_notrace : NULL; + } if (file->f_mode & FMODE_WRITE) { const int size_bits = FTRACE_HASH_DEFAULT_BITS; - if (file->f_flags & O_TRUNC) + if (file->f_flags & O_TRUNC) { iter->hash = alloc_ftrace_hash(size_bits); - else + clear_ftrace_mod_list(mod_head); + } else { iter->hash = alloc_and_copy_ftrace_hash(size_bits, hash); + } if (!iter->hash) { trace_parser_put(&iter->parser); @@ -3761,6 +3819,68 @@ static int ftrace_hash_move_and_update_ops(struct ftrace_ops *ops, return ret; } +static bool module_exists(const char *module) +{ + /* All modules have the symbol __this_module */ + const char this_mod[] = "__this_module"; + const int modname_size = MAX_PARAM_PREFIX_LEN + sizeof(this_mod) + 1; + char modname[modname_size + 1]; + unsigned long val; + int n; + + n = snprintf(modname, modname_size + 1, "%s:%s", module, this_mod); + + if (n > modname_size) + return false; + + val = module_kallsyms_lookup_name(modname); + return val != 0; +} + +static int cache_mod(struct trace_array *tr, + const char *func, char *module, int enable) +{ + struct ftrace_mod_load *ftrace_mod, *n; + struct list_head *head = enable ? &tr->mod_trace : &tr->mod_notrace; + int ret; + + mutex_lock(&ftrace_lock); + + /* We do not cache inverse filters */ + if (func[0] == '!') { + func++; + ret = -EINVAL; + + /* Look to remove this hash */ + list_for_each_entry_safe(ftrace_mod, n, head, list) { + if (strcmp(ftrace_mod->module, module) != 0) + continue; + + /* no func matches all */ + if (!func || strcmp(func, "*") == 0 || + (ftrace_mod->func && + strcmp(ftrace_mod->func, func) == 0)) { + ret = 0; + free_ftrace_mod(ftrace_mod); + continue; + } + } + goto out; + } + + ret = -EINVAL; + /* We only care about modules that have not been loaded yet */ + if (module_exists(module)) + goto out; + + /* Save this string off, and execute it when the module is loaded */ + ret = ftrace_add_mod(tr, func, module, enable); + out: + mutex_unlock(&ftrace_lock); + + return ret; +} + /* * We register the module command as a template to show others how * to register the a command as well. @@ -3768,10 +3888,16 @@ static int ftrace_hash_move_and_update_ops(struct ftrace_ops *ops, static int ftrace_mod_callback(struct trace_array *tr, struct ftrace_hash *hash, - char *func, char *cmd, char *module, int enable) + char *func_orig, char *cmd, char *module, int enable) { + char *func; int ret; + /* match_records() modifies func, and we need the original */ + func = kstrdup(func_orig, GFP_KERNEL); + if (!func) + return -ENOMEM; + /* * cmd == 'mod' because we only registered this func * for the 'mod' ftrace_func_command. @@ -3780,8 +3906,10 @@ ftrace_mod_callback(struct trace_array *tr, struct ftrace_hash *hash, * parameter. */ ret = match_records(hash, func, strlen(func), module); + kfree(func); + if (!ret) - return -EINVAL; + return cache_mod(tr, func_orig, module, enable); if (ret < 0) return ret; return 0; @@ -5570,6 +5698,8 @@ static void ftrace_update_trampoline(struct ftrace_ops *ops) void ftrace_init_trace_array(struct trace_array *tr) { INIT_LIST_HEAD(&tr->func_probes); + INIT_LIST_HEAD(&tr->mod_trace); + INIT_LIST_HEAD(&tr->mod_notrace); } #else |