diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index 7fd0f8576e4c0..4cee3442bcced 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -678,6 +678,21 @@ static int register_trace_kprobe(struct trace_kprobe *tk) } #ifdef CONFIG_MODULES +static int validate_module_probe_symbol(const char *modname, const char *symbol); + +static int register_module_trace_kprobe(struct module *mod, struct trace_kprobe *tk) +{ + const char *p; + int ret = 0; + + p = strchr(trace_kprobe_symbol(tk), ':'); + if (p) + ret = validate_module_probe_symbol(module_name(mod), p + 1); + if (!ret) + ret = __register_trace_kprobe(tk); + return ret; +} + /* Module notifier call back, checking event on the module */ static int trace_kprobe_module_callback(struct notifier_block *nb, unsigned long val, void *data) @@ -696,7 +711,7 @@ static int trace_kprobe_module_callback(struct notifier_block *nb, if (trace_kprobe_within_module(tk, mod)) { /* Don't need to check busy - this should have gone. */ __unregister_trace_kprobe(tk); - ret = __register_trace_kprobe(tk); + ret = register_module_trace_kprobe(mod, tk); if (ret) pr_warn("Failed to re-register probe %s on %s: %d\n", trace_probe_name(&tk->tp), @@ -747,17 +762,68 @@ static int count_mod_symbols(void *data, const char *name, unsigned long unused) return 0; } -static unsigned int number_of_same_symbols(char *func_name) +static unsigned int number_of_same_symbols(const char *mod, const char *func_name) { struct sym_count_ctx ctx = { .count = 0, .name = func_name }; - kallsyms_on_each_match_symbol(count_symbols, func_name, &ctx.count); + if (!mod) + kallsyms_on_each_match_symbol(count_symbols, func_name, &ctx.count); - module_kallsyms_on_each_symbol(NULL, count_mod_symbols, &ctx); + module_kallsyms_on_each_symbol(mod, count_mod_symbols, &ctx); return ctx.count; } +static int validate_module_probe_symbol(const char *modname, const char *symbol) +{ + unsigned int count = number_of_same_symbols(modname, symbol); + + if (count > 1) { + /* + * Users should use ADDR to remove the ambiguity of + * using KSYM only. + */ + return -EADDRNOTAVAIL; + } else if (count == 0) { + /* + * We can return ENOENT earlier than when register the + * kprobe. + */ + return -ENOENT; + } + return 0; +} + +static int validate_probe_symbol(char *symbol) +{ + struct module *mod = NULL; + char *modname = NULL, *p; + int ret = 0; + + p = strchr(symbol, ':'); + if (p) { + modname = symbol; + symbol = p + 1; + *p = '\0'; + /* Return 0 (defer) if the module does not exist yet. */ + rcu_read_lock_sched(); + mod = find_module(modname); + if (mod && !try_module_get(mod)) + mod = NULL; + rcu_read_unlock_sched(); + if (!mod) + goto out; + } + + ret = validate_module_probe_symbol(modname, symbol); +out: + if (p) + *p = ':'; + if (mod) + module_put(mod); + return ret; +} + static int trace_kprobe_entry_handler(struct kretprobe_instance *ri, struct pt_regs *regs); @@ -881,6 +947,14 @@ static int __trace_kprobe_create(int argc, const char *argv[]) trace_probe_log_err(0, BAD_PROBE_ADDR); goto parse_error; } + ret = validate_probe_symbol(symbol); + if (ret) { + if (ret == -EADDRNOTAVAIL) + trace_probe_log_err(0, NON_UNIQ_SYMBOL); + else + trace_probe_log_err(0, BAD_PROBE_ADDR); + goto parse_error; + } if (is_return) ctx.flags |= TPARG_FL_RETURN; ret = kprobe_on_func_entry(NULL, symbol, offset); @@ -893,31 +967,6 @@ static int __trace_kprobe_create(int argc, const char *argv[]) } } - if (symbol && !strchr(symbol, ':')) { - unsigned int count; - - count = number_of_same_symbols(symbol); - if (count > 1) { - /* - * Users should use ADDR to remove the ambiguity of - * using KSYM only. - */ - trace_probe_log_err(0, NON_UNIQ_SYMBOL); - ret = -EADDRNOTAVAIL; - - goto error; - } else if (count == 0) { - /* - * We can return ENOENT earlier than when register the - * kprobe. - */ - trace_probe_log_err(0, BAD_PROBE_ADDR); - ret = -ENOENT; - - goto error; - } - } - trace_probe_log_set_index(0); if (event) { ret = traceprobe_parse_event_name(&event, &group, gbuf, @@ -1835,21 +1884,9 @@ create_local_trace_kprobe(char *func, void *addr, unsigned long offs, char *event; if (func) { - unsigned int count; - - count = number_of_same_symbols(func); - if (count > 1) - /* - * Users should use addr to remove the ambiguity of - * using func only. - */ - return ERR_PTR(-EADDRNOTAVAIL); - else if (count == 0) - /* - * We can return ENOENT earlier than when register the - * kprobe. - */ - return ERR_PTR(-ENOENT); + ret = validate_probe_symbol(func); + if (ret) + return ERR_PTR(ret); } /*