diff options
Diffstat (limited to 'kernel/trace/ftrace.c')
| -rw-r--r-- | kernel/trace/ftrace.c | 110 |
1 files changed, 66 insertions, 44 deletions
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 439e2ab6905e..442438b93fe9 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -163,7 +163,7 @@ static void ftrace_sync_ipi(void *data) static ftrace_func_t ftrace_ops_get_list_func(struct ftrace_ops *ops) { /* - * If this is a dynamic, RCU, or per CPU ops, or we force list func, + * If this is a dynamic or RCU ops, or we force list func, * then it needs to call the list anyway. */ if (ops->flags & (FTRACE_OPS_FL_DYNAMIC | FTRACE_OPS_FL_RCU) || @@ -1289,6 +1289,7 @@ static int ftrace_add_mod(struct trace_array *tr, if (!ftrace_mod) return -ENOMEM; + INIT_LIST_HEAD(&ftrace_mod->list); ftrace_mod->func = kstrdup(func, GFP_KERNEL); ftrace_mod->module = kstrdup(module, GFP_KERNEL); ftrace_mod->enable = enable; @@ -1644,6 +1645,18 @@ ftrace_find_tramp_ops_any_other(struct dyn_ftrace *rec, struct ftrace_ops *op_ex static struct ftrace_ops * ftrace_find_tramp_ops_next(struct dyn_ftrace *rec, struct ftrace_ops *ops); +static bool skip_record(struct dyn_ftrace *rec) +{ + /* + * At boot up, weak functions are set to disable. Function tracing + * can be enabled before they are, and they still need to be disabled now. + * If the record is disabled, still continue if it is marked as already + * enabled (this is needed to keep the accounting working). + */ + return rec->flags & FTRACE_FL_DISABLED && + !(rec->flags & FTRACE_FL_ENABLED); +} + static bool __ftrace_hash_rec_update(struct ftrace_ops *ops, int filter_hash, bool inc) @@ -1693,7 +1706,7 @@ static bool __ftrace_hash_rec_update(struct ftrace_ops *ops, int in_hash = 0; int match = 0; - if (rec->flags & FTRACE_FL_DISABLED) + if (skip_record(rec)) continue; if (all) { @@ -2016,7 +2029,6 @@ static int ftrace_hash_ipmodify_update(struct ftrace_ops *ops, static void print_ip_ins(const char *fmt, const unsigned char *p) { char ins[MCOUNT_INSN_SIZE]; - int i; if (copy_from_kernel_nofault(ins, p, MCOUNT_INSN_SIZE)) { printk(KERN_CONT "%s[FAULT] %px\n", fmt, p); @@ -2024,9 +2036,7 @@ static void print_ip_ins(const char *fmt, const unsigned char *p) } printk(KERN_CONT "%s", fmt); - - for (i = 0; i < MCOUNT_INSN_SIZE; i++) - printk(KERN_CONT "%s%02x", i ? ":" : "", ins[i]); + pr_cont("%*phC", MCOUNT_INSN_SIZE, ins); } enum ftrace_bug_type ftrace_bug_type; @@ -2126,7 +2136,7 @@ static int ftrace_check_record(struct dyn_ftrace *rec, bool enable, bool update) ftrace_bug_type = FTRACE_BUG_UNKNOWN; - if (rec->flags & FTRACE_FL_DISABLED) + if (skip_record(rec)) return FTRACE_UPDATE_IGNORE; /* @@ -2241,7 +2251,7 @@ static int ftrace_check_record(struct dyn_ftrace *rec, bool enable, bool update) if (update) { /* If there's no more users, clear all flags */ if (!ftrace_rec_count(rec)) - rec->flags = 0; + rec->flags &= FTRACE_FL_DISABLED; else /* * Just disable the record, but keep the ops TRAMP @@ -2478,14 +2488,13 @@ ftrace_add_rec_direct(unsigned long ip, unsigned long addr, static void call_direct_funcs(unsigned long ip, unsigned long pip, struct ftrace_ops *ops, struct ftrace_regs *fregs) { - struct pt_regs *regs = ftrace_get_regs(fregs); unsigned long addr; addr = ftrace_find_rec_direct(ip); if (!addr) return; - arch_ftrace_set_direct_caller(regs, addr); + arch_ftrace_set_direct_caller(fregs, addr); } struct ftrace_ops direct_ops = { @@ -2634,7 +2643,7 @@ void __weak ftrace_replace_code(int mod_flags) do_for_each_ftrace_rec(pg, rec) { - if (rec->flags & FTRACE_FL_DISABLED) + if (skip_record(rec)) continue; failed = __ftrace_replace_code(rec, enable); @@ -2753,6 +2762,19 @@ void __weak ftrace_arch_code_modify_post_process(void) { } +static int update_ftrace_func(ftrace_func_t func) +{ + static ftrace_func_t save_func; + + /* Avoid updating if it hasn't changed */ + if (func == save_func) + return 0; + + save_func = func; + + return ftrace_update_ftrace_func(func); +} + void ftrace_modify_all_code(int command) { int update = command & FTRACE_UPDATE_TRACE_FUNC; @@ -2773,7 +2795,7 @@ void ftrace_modify_all_code(int command) * traced. */ if (update) { - err = ftrace_update_ftrace_func(ftrace_ops_list_func); + err = update_ftrace_func(ftrace_ops_list_func); if (FTRACE_WARN_ON(err)) return; } @@ -2789,7 +2811,7 @@ void ftrace_modify_all_code(int command) /* If irqs are disabled, we are in stop machine */ if (!irqs_disabled()) smp_call_function(ftrace_sync_ipi, NULL, 1); - err = ftrace_update_ftrace_func(ftrace_trace_function); + err = update_ftrace_func(ftrace_trace_function); if (FTRACE_WARN_ON(err)) return; } @@ -3019,18 +3041,8 @@ int ftrace_shutdown(struct ftrace_ops *ops, int command) command |= FTRACE_UPDATE_TRACE_FUNC; } - if (!command || !ftrace_enabled) { - /* - * If these are dynamic or per_cpu ops, they still - * need their data freed. Since, function tracing is - * not currently active, we can just free them - * without synchronizing all CPUs. - */ - if (ops->flags & FTRACE_OPS_FL_DYNAMIC) - goto free_ops; - - return 0; - } + if (!command || !ftrace_enabled) + goto out; /* * If the ops uses a trampoline, then it needs to be @@ -3067,11 +3079,10 @@ int ftrace_shutdown(struct ftrace_ops *ops, int command) removed_ops = NULL; ops->flags &= ~FTRACE_OPS_FL_REMOVING; +out: /* * Dynamic ops may be freed, we must make sure that all * callers are done before leaving this function. - * The same goes for freeing the per_cpu data of the per_cpu - * ops. */ if (ops->flags & FTRACE_OPS_FL_DYNAMIC) { /* @@ -3094,7 +3105,6 @@ int ftrace_shutdown(struct ftrace_ops *ops, int command) if (IS_ENABLED(CONFIG_PREEMPTION)) synchronize_rcu_tasks(); - free_ops: ftrace_trampoline_free(ops); } @@ -3191,7 +3201,7 @@ static int ftrace_allocate_records(struct ftrace_page *pg, int count) /* if we can't allocate this size, try something smaller */ if (!order) return -ENOMEM; - order >>= 1; + order--; goto again; } @@ -4193,6 +4203,7 @@ match_records(struct ftrace_hash *hash, char *func, int len, char *mod) } found = 1; } + cond_resched(); } while_for_each_ftrace_rec(); out_unlock: mutex_unlock(&ftrace_lock); @@ -5427,6 +5438,8 @@ static struct ftrace_ops stub_ops = { * it is safe to modify the ftrace record, where it should be * currently calling @old_addr directly, to call @new_addr. * + * This is called with direct_mutex locked. + * * Safety checks should be made to make sure that the code at * @rec->ip is currently calling @old_addr. And this must * also update entry->direct to @new_addr. @@ -5439,6 +5452,8 @@ int __weak ftrace_modify_direct_caller(struct ftrace_func_entry *entry, unsigned long ip = rec->ip; int ret; + lockdep_assert_held(&direct_mutex); + /* * The ftrace_lock was used to determine if the record * had more than one registered user to it. If it did, @@ -5461,7 +5476,7 @@ int __weak ftrace_modify_direct_caller(struct ftrace_func_entry *entry, if (ret) goto out_lock; - ret = register_ftrace_function(&stub_ops); + ret = register_ftrace_function_nolock(&stub_ops); if (ret) { ftrace_set_filter_ip(&stub_ops, ip, 1, 0); goto out_lock; @@ -6081,8 +6096,12 @@ int ftrace_regex_release(struct inode *inode, struct file *file) if (filter_hash) { orig_hash = &iter->ops->func_hash->filter_hash; - if (iter->tr && !list_empty(&iter->tr->mod_trace)) - iter->hash->flags |= FTRACE_HASH_FL_MOD; + if (iter->tr) { + if (list_empty(&iter->tr->mod_trace)) + iter->hash->flags &= ~FTRACE_HASH_FL_MOD; + else + iter->hash->flags |= FTRACE_HASH_FL_MOD; + } } else orig_hash = &iter->ops->func_hash->notrace_hash; @@ -7384,7 +7403,7 @@ void __init ftrace_init(void) } pr_info("ftrace: allocating %ld entries in %ld pages\n", - count, count / ENTRIES_PER_PAGE + 1); + count, DIV_ROUND_UP(count, ENTRIES_PER_PAGE)); ret = ftrace_process_locs(NULL, __start_mcount_loc, @@ -7511,8 +7530,6 @@ __ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip, /* * Check the following for each ops before calling their func: * if RCU flag is set, then rcu_is_watching() must be true - * if PER_CPU is set, then ftrace_function_local_disable() - * must be false * Otherwise test if the ip matches the ops filter * * If any of the above fails then the op->func() is not executed. @@ -7562,8 +7579,8 @@ NOKPROBE_SYMBOL(arch_ftrace_ops_list_func); /* * If there's only one function registered but it does not support - * recursion, needs RCU protection and/or requires per cpu handling, then - * this function will be called by the mcount trampoline. + * recursion, needs RCU protection, then this function will be called + * by the mcount trampoline. */ static void ftrace_ops_assist_func(unsigned long ip, unsigned long parent_ip, struct ftrace_ops *op, struct ftrace_regs *fregs) @@ -8250,6 +8267,10 @@ struct kallsyms_data { size_t found; }; +/* This function gets called for all kernel and module symbols + * and returns 1 in case we resolved all the requested symbols, + * 0 otherwise. + */ static int kallsyms_callback(void *data, const char *name, struct module *mod, unsigned long addr) { @@ -8265,8 +8286,7 @@ static int kallsyms_callback(void *data, const char *name, if (args->addrs[idx]) return 0; - addr = ftrace_location(addr); - if (!addr) + if (!ftrace_location(addr)) return 0; args->addrs[idx] = addr; @@ -8293,17 +8313,19 @@ static int kallsyms_callback(void *data, const char *name, int ftrace_lookup_symbols(const char **sorted_syms, size_t cnt, unsigned long *addrs) { struct kallsyms_data args; - int err; + int found_all; memset(addrs, 0, sizeof(*addrs) * cnt); args.addrs = addrs; args.syms = sorted_syms; args.cnt = cnt; args.found = 0; - err = kallsyms_on_each_symbol(kallsyms_callback, &args); - if (err < 0) - return err; - return args.found == args.cnt ? 0 : -ESRCH; + + found_all = kallsyms_on_each_symbol(kallsyms_callback, &args); + if (found_all) + return 0; + found_all = module_kallsyms_on_each_symbol(kallsyms_callback, &args); + return found_all ? 0 : -ESRCH; } #ifdef CONFIG_SYSCTL |