diff options
Diffstat (limited to 'kernel/trace/ftrace.c')
| -rw-r--r-- | kernel/trace/ftrace.c | 494 |
1 files changed, 401 insertions, 93 deletions
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 6105b7036482..601ccf1b2f09 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -45,6 +45,8 @@ #include "trace_output.h" #include "trace_stat.h" +#define FTRACE_INVALID_FUNCTION "__ftrace_invalid_address__" + #define FTRACE_WARN_ON(cond) \ ({ \ int ___r = cond; \ @@ -86,7 +88,7 @@ struct ftrace_ops ftrace_list_end __read_mostly = { /* ftrace_enabled is a method to turn ftrace on or off */ int ftrace_enabled __read_mostly; -static int last_ftrace_enabled; +static int __maybe_unused last_ftrace_enabled; /* Current function tracing op */ struct ftrace_ops *function_trace_op __read_mostly = &ftrace_list_end; @@ -119,7 +121,7 @@ struct ftrace_ops __rcu *ftrace_ops_list __read_mostly = &ftrace_list_end; ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub; struct ftrace_ops global_ops; -/* Defined by vmlinux.lds.h see the commment above arch_ftrace_ops_list_func for details */ +/* Defined by vmlinux.lds.h see the comment above arch_ftrace_ops_list_func for details */ void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip, struct ftrace_ops *op, struct ftrace_regs *fregs); @@ -952,7 +954,6 @@ static struct tracer_stat function_stats __initdata = { static __init void ftrace_profile_tracefs(struct dentry *d_tracer) { struct ftrace_profile_stat *stat; - struct dentry *entry; char *name; int ret; int cpu; @@ -983,11 +984,9 @@ static __init void ftrace_profile_tracefs(struct dentry *d_tracer) } } - entry = tracefs_create_file("function_profile_enabled", - TRACE_MODE_WRITE, d_tracer, NULL, - &ftrace_profile_fops); - if (!entry) - pr_warn("Could not create tracefs 'function_profile_enabled' entry\n"); + trace_create_file("function_profile_enabled", + TRACE_MODE_WRITE, d_tracer, NULL, + &ftrace_profile_fops); } #else /* CONFIG_FUNCTION_PROFILER */ @@ -1568,17 +1567,34 @@ unsigned long ftrace_location_range(unsigned long start, unsigned long end) } /** - * ftrace_location - return true if the ip giving is a traced location + * ftrace_location - return the ftrace location * @ip: the instruction pointer to check * - * Returns rec->ip if @ip given is a pointer to a ftrace location. - * That is, the instruction that is either a NOP or call to - * the function tracer. It checks the ftrace internal tables to - * determine if the address belongs or not. + * If @ip matches the ftrace location, return @ip. + * If @ip matches sym+0, return sym's ftrace location. + * Otherwise, return 0. */ unsigned long ftrace_location(unsigned long ip) { - return ftrace_location_range(ip, ip); + struct dyn_ftrace *rec; + unsigned long offset; + unsigned long size; + + rec = lookup_rec(ip, ip); + if (!rec) { + if (!kallsyms_lookup_size_offset(ip, &size, &offset)) + goto out; + + /* map sym+0 to __fentry__ */ + if (!offset) + rec = lookup_rec(ip, ip + size - 1); + } + + if (rec) + return rec->ip; + +out: + return 0; } /** @@ -2690,18 +2706,16 @@ ftrace_nop_initialize(struct module *mod, struct dyn_ftrace *rec) * archs can override this function if they must do something * before the modifying code is performed. */ -int __weak ftrace_arch_code_modify_prepare(void) +void __weak ftrace_arch_code_modify_prepare(void) { - return 0; } /* * archs can override this function if they must do something * after the modifying code is performed. */ -int __weak ftrace_arch_code_modify_post_process(void) +void __weak ftrace_arch_code_modify_post_process(void) { - return 0; } void ftrace_modify_all_code(int command) @@ -2787,12 +2801,7 @@ void __weak arch_ftrace_update_code(int command) static void ftrace_run_update_code(int command) { - int ret; - - ret = ftrace_arch_code_modify_prepare(); - FTRACE_WARN_ON(ret); - if (ret) - return; + ftrace_arch_code_modify_prepare(); /* * By default we use stop_machine() to modify the code. @@ -2802,8 +2811,7 @@ static void ftrace_run_update_code(int command) */ arch_ftrace_update_code(command); - ret = ftrace_arch_code_modify_post_process(); - FTRACE_WARN_ON(ret); + ftrace_arch_code_modify_post_process(); } static void ftrace_run_modify_code(struct ftrace_ops *ops, int command, @@ -3048,40 +3056,6 @@ int ftrace_shutdown(struct ftrace_ops *ops, int command) return 0; } -static void ftrace_startup_sysctl(void) -{ - int command; - - if (unlikely(ftrace_disabled)) - return; - - /* Force update next time */ - saved_ftrace_func = NULL; - /* ftrace_start_up is true if we want ftrace running */ - if (ftrace_start_up) { - command = FTRACE_UPDATE_CALLS; - if (ftrace_graph_active) - command |= FTRACE_START_FUNC_RET; - ftrace_startup_enable(command); - } -} - -static void ftrace_shutdown_sysctl(void) -{ - int command; - - if (unlikely(ftrace_disabled)) - return; - - /* ftrace_start_up is true if ftrace is running */ - if (ftrace_start_up) { - command = FTRACE_DISABLE_CALLS; - if (ftrace_graph_active) - command |= FTRACE_STOP_FUNC_RET; - ftrace_run_update_code(command); - } -} - static u64 ftrace_update_time; unsigned long ftrace_update_tot_cnt; unsigned long ftrace_number_of_pages; @@ -3648,6 +3622,105 @@ static void add_trampoline_func(struct seq_file *m, struct ftrace_ops *ops, seq_printf(m, " ->%pS", ptr); } +#ifdef FTRACE_MCOUNT_MAX_OFFSET +/* + * Weak functions can still have an mcount/fentry that is saved in + * the __mcount_loc section. These can be detected by having a + * symbol offset of greater than FTRACE_MCOUNT_MAX_OFFSET, as the + * symbol found by kallsyms is not the function that the mcount/fentry + * is part of. The offset is much greater in these cases. + * + * Test the record to make sure that the ip points to a valid kallsyms + * and if not, mark it disabled. + */ +static int test_for_valid_rec(struct dyn_ftrace *rec) +{ + char str[KSYM_SYMBOL_LEN]; + unsigned long offset; + const char *ret; + + ret = kallsyms_lookup(rec->ip, NULL, &offset, NULL, str); + + /* Weak functions can cause invalid addresses */ + if (!ret || offset > FTRACE_MCOUNT_MAX_OFFSET) { + rec->flags |= FTRACE_FL_DISABLED; + return 0; + } + return 1; +} + +static struct workqueue_struct *ftrace_check_wq __initdata; +static struct work_struct ftrace_check_work __initdata; + +/* + * Scan all the mcount/fentry entries to make sure they are valid. + */ +static __init void ftrace_check_work_func(struct work_struct *work) +{ + struct ftrace_page *pg; + struct dyn_ftrace *rec; + + mutex_lock(&ftrace_lock); + do_for_each_ftrace_rec(pg, rec) { + test_for_valid_rec(rec); + } while_for_each_ftrace_rec(); + mutex_unlock(&ftrace_lock); +} + +static int __init ftrace_check_for_weak_functions(void) +{ + INIT_WORK(&ftrace_check_work, ftrace_check_work_func); + + ftrace_check_wq = alloc_workqueue("ftrace_check_wq", WQ_UNBOUND, 0); + + queue_work(ftrace_check_wq, &ftrace_check_work); + return 0; +} + +static int __init ftrace_check_sync(void) +{ + /* Make sure the ftrace_check updates are finished */ + if (ftrace_check_wq) + destroy_workqueue(ftrace_check_wq); + return 0; +} + +late_initcall_sync(ftrace_check_sync); +subsys_initcall(ftrace_check_for_weak_functions); + +static int print_rec(struct seq_file *m, unsigned long ip) +{ + unsigned long offset; + char str[KSYM_SYMBOL_LEN]; + char *modname; + const char *ret; + + ret = kallsyms_lookup(ip, NULL, &offset, &modname, str); + /* Weak functions can cause invalid addresses */ + if (!ret || offset > FTRACE_MCOUNT_MAX_OFFSET) { + snprintf(str, KSYM_SYMBOL_LEN, "%s_%ld", + FTRACE_INVALID_FUNCTION, offset); + ret = NULL; + } + + seq_puts(m, str); + if (modname) + seq_printf(m, " [%s]", modname); + return ret == NULL ? -1 : 0; +} +#else +static inline int test_for_valid_rec(struct dyn_ftrace *rec) +{ + return 1; +} + +static inline int print_rec(struct seq_file *m, unsigned long ip) +{ + seq_printf(m, "%ps", (void *)ip); + return 0; +} +#endif + static int t_show(struct seq_file *m, void *v) { struct ftrace_iterator *iter = m->private; @@ -3672,7 +3745,13 @@ static int t_show(struct seq_file *m, void *v) if (!rec) return 0; - seq_printf(m, "%ps", (void *)rec->ip); + if (print_rec(m, rec->ip)) { + /* This should only happen when a rec is disabled */ + WARN_ON_ONCE(!(rec->flags & FTRACE_FL_DISABLED)); + seq_putc(m, '\n'); + return 0; + } + if (iter->flags & FTRACE_ITER_ENABLED) { struct ftrace_ops *ops; @@ -3990,6 +4069,24 @@ add_rec_by_index(struct ftrace_hash *hash, struct ftrace_glob *func_g, return 0; } +#ifdef FTRACE_MCOUNT_MAX_OFFSET +static int lookup_ip(unsigned long ip, char **modname, char *str) +{ + unsigned long offset; + + kallsyms_lookup(ip, NULL, &offset, modname, str); + if (offset > FTRACE_MCOUNT_MAX_OFFSET) + return -1; + return 0; +} +#else +static int lookup_ip(unsigned long ip, char **modname, char *str) +{ + kallsyms_lookup(ip, NULL, NULL, modname, str); + return 0; +} +#endif + static int ftrace_match_record(struct dyn_ftrace *rec, struct ftrace_glob *func_g, struct ftrace_glob *mod_g, int exclude_mod) @@ -3997,7 +4094,12 @@ ftrace_match_record(struct dyn_ftrace *rec, struct ftrace_glob *func_g, char str[KSYM_SYMBOL_LEN]; char *modname; - kallsyms_lookup(rec->ip, NULL, NULL, &modname, str); + if (lookup_ip(rec->ip, &modname, str)) { + /* This should only happen when a rec is disabled */ + WARN_ON_ONCE(system_state == SYSTEM_RUNNING && + !(rec->flags & FTRACE_FL_DISABLED)); + return 0; + } if (mod_g) { int mod_matches = (modname) ? ftrace_match(modname, mod_g) : 0; @@ -4448,7 +4550,7 @@ int ftrace_func_mapper_add_ip(struct ftrace_func_mapper *mapper, * @ip: The instruction pointer address to remove the data from * * Returns the data if it is found, otherwise NULL. - * Note, if the data pointer is used as the data itself, (see + * Note, if the data pointer is used as the data itself, (see * ftrace_func_mapper_find_ip(), then the return value may be meaningless, * if the data pointer was set to zero. */ @@ -4543,8 +4645,8 @@ register_ftrace_function_probe(char *glob, struct trace_array *tr, struct ftrace_probe_ops *probe_ops, void *data) { + struct ftrace_func_probe *probe = NULL, *iter; struct ftrace_func_entry *entry; - struct ftrace_func_probe *probe; struct ftrace_hash **orig_hash; struct ftrace_hash *old_hash; struct ftrace_hash *hash; @@ -4563,11 +4665,13 @@ register_ftrace_function_probe(char *glob, struct trace_array *tr, mutex_lock(&ftrace_lock); /* Check if the probe_ops is already registered */ - list_for_each_entry(probe, &tr->func_probes, list) { - if (probe->probe_ops == probe_ops) + list_for_each_entry(iter, &tr->func_probes, list) { + if (iter->probe_ops == probe_ops) { + probe = iter; break; + } } - if (&probe->list == &tr->func_probes) { + if (!probe) { probe = kzalloc(sizeof(*probe), GFP_KERNEL); if (!probe) { mutex_unlock(&ftrace_lock); @@ -4685,9 +4789,9 @@ int unregister_ftrace_function_probe_func(char *glob, struct trace_array *tr, struct ftrace_probe_ops *probe_ops) { + struct ftrace_func_probe *probe = NULL, *iter; struct ftrace_ops_hash old_hash_ops; struct ftrace_func_entry *entry; - struct ftrace_func_probe *probe; struct ftrace_glob func_g; struct ftrace_hash **orig_hash; struct ftrace_hash *old_hash; @@ -4715,11 +4819,13 @@ unregister_ftrace_function_probe_func(char *glob, struct trace_array *tr, mutex_lock(&ftrace_lock); /* Check if the probe_ops is already registered */ - list_for_each_entry(probe, &tr->func_probes, list) { - if (probe->probe_ops == probe_ops) + list_for_each_entry(iter, &tr->func_probes, list) { + if (iter->probe_ops == probe_ops) { + probe = iter; break; + } } - if (&probe->list == &tr->func_probes) + if (!probe) goto err_unlock_ftrace; ret = -EINVAL; @@ -4958,11 +5064,12 @@ ftrace_notrace_write(struct file *file, const char __user *ubuf, } static int -ftrace_match_addr(struct ftrace_hash *hash, unsigned long ip, int remove) +__ftrace_match_addr(struct ftrace_hash *hash, unsigned long ip, int remove) { struct ftrace_func_entry *entry; - if (!ftrace_location(ip)) + ip = ftrace_location(ip); + if (!ip) return -EINVAL; if (remove) { @@ -4977,8 +5084,29 @@ ftrace_match_addr(struct ftrace_hash *hash, unsigned long ip, int remove) } static int +ftrace_match_addr(struct ftrace_hash *hash, unsigned long *ips, + unsigned int cnt, int remove) +{ + unsigned int i; + int err; + + for (i = 0; i < cnt; i++) { + err = __ftrace_match_addr(hash, ips[i], remove); + if (err) { + /* + * This expects the @hash is a temporary hash and if this + * fails the caller must free the @hash. + */ + return err; + } + } + return 0; +} + +static int ftrace_set_hash(struct ftrace_ops *ops, unsigned char *buf, int len, - unsigned long ip, int remove, int reset, int enable) + unsigned long *ips, unsigned int cnt, + int remove, int reset, int enable) { struct ftrace_hash **orig_hash; struct ftrace_hash *hash; @@ -5008,8 +5136,8 @@ ftrace_set_hash(struct ftrace_ops *ops, unsigned char *buf, int len, ret = -EINVAL; goto out_regex_unlock; } - if (ip) { - ret = ftrace_match_addr(hash, ip, remove); + if (ips) { + ret = ftrace_match_addr(hash, ips, cnt, remove); if (ret < 0) goto out_regex_unlock; } @@ -5026,10 +5154,10 @@ ftrace_set_hash(struct ftrace_ops *ops, unsigned char *buf, int len, } static int -ftrace_set_addr(struct ftrace_ops *ops, unsigned long ip, int remove, - int reset, int enable) +ftrace_set_addr(struct ftrace_ops *ops, unsigned long *ips, unsigned int cnt, + int remove, int reset, int enable) { - return ftrace_set_hash(ops, NULL, 0, ip, remove, reset, enable); + return ftrace_set_hash(ops, NULL, 0, ips, cnt, remove, reset, enable); } #ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS @@ -5110,11 +5238,16 @@ int register_ftrace_direct(unsigned long ip, unsigned long addr) struct ftrace_func_entry *entry; struct ftrace_hash *free_hash = NULL; struct dyn_ftrace *rec; - int ret = -EBUSY; + int ret = -ENODEV; mutex_lock(&direct_mutex); + ip = ftrace_location(ip); + if (!ip) + goto out_unlock; + /* See if there's a direct function at @ip already */ + ret = -EBUSY; if (ftrace_find_rec_direct(ip)) goto out_unlock; @@ -5151,8 +5284,6 @@ int register_ftrace_direct(unsigned long ip, unsigned long addr) goto out_unlock; ret = ftrace_set_filter_ip(&direct_ops, ip, 0, 0); - if (ret) - remove_hash_entry(direct_functions, entry); if (!ret && !(direct_ops.flags & FTRACE_OPS_FL_ENABLED)) { ret = register_ftrace_function(&direct_ops); @@ -5161,6 +5292,7 @@ int register_ftrace_direct(unsigned long ip, unsigned long addr) } if (ret) { + remove_hash_entry(direct_functions, entry); kfree(entry); if (!direct->count) { list_del_rcu(&direct->next); @@ -5222,6 +5354,10 @@ int unregister_ftrace_direct(unsigned long ip, unsigned long addr) mutex_lock(&direct_mutex); + ip = ftrace_location(ip); + if (!ip) + goto out_unlock; + entry = find_direct_entry(&ip, NULL); if (!entry) goto out_unlock; @@ -5354,6 +5490,11 @@ int modify_ftrace_direct(unsigned long ip, mutex_lock(&direct_mutex); mutex_lock(&ftrace_lock); + + ip = ftrace_location(ip); + if (!ip) + goto out_unlock; + entry = find_direct_entry(&ip, &rec); if (!entry) goto out_unlock; @@ -5634,11 +5775,30 @@ int ftrace_set_filter_ip(struct ftrace_ops *ops, unsigned long ip, int remove, int reset) { ftrace_ops_init(ops); - return ftrace_set_addr(ops, ip, remove, reset, 1); + return ftrace_set_addr(ops, &ip, 1, remove, reset, 1); } EXPORT_SYMBOL_GPL(ftrace_set_filter_ip); /** + * ftrace_set_filter_ips - set functions to filter on in ftrace by addresses + * @ops - the ops to set the filter with + * @ips - the array of addresses to add to or remove from the filter. + * @cnt - the number of addresses in @ips + * @remove - non zero to remove ips from the filter + * @reset - non zero to reset all filters before applying this filter. + * + * Filters denote which functions should be enabled when tracing is enabled + * If @ips array or any ip specified within is NULL , it fails to update filter. + */ +int ftrace_set_filter_ips(struct ftrace_ops *ops, unsigned long *ips, + unsigned int cnt, int remove, int reset) +{ + ftrace_ops_init(ops); + return ftrace_set_addr(ops, ips, cnt, remove, reset, 1); +} +EXPORT_SYMBOL_GPL(ftrace_set_filter_ips); + +/** * ftrace_ops_set_global_filter - setup ops to use global filters * @ops - the ops which will use the global filters * @@ -5659,7 +5819,7 @@ static int ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len, int reset, int enable) { - return ftrace_set_hash(ops, buf, len, 0, 0, reset, enable); + return ftrace_set_hash(ops, buf, len, NULL, 0, 0, reset, enable); } /** @@ -6755,6 +6915,13 @@ void ftrace_module_enable(struct module *mod) !within_module_init(rec->ip, mod)) break; + /* Weak functions should still be ignored */ + if (!test_for_valid_rec(rec)) { + /* Clear all other flags. Should not be enabled anyway */ + rec->flags = FTRACE_FL_DISABLED; + continue; + } + cnt = 0; /* @@ -6791,11 +6958,16 @@ void ftrace_module_enable(struct module *mod) void ftrace_module_init(struct module *mod) { + int ret; + if (ftrace_disabled || !mod->num_ftrace_callsites) return; - ftrace_process_locs(mod, mod->ftrace_callsites, - mod->ftrace_callsites + mod->num_ftrace_callsites); + ret = ftrace_process_locs(mod, mod->ftrace_callsites, + mod->ftrace_callsites + mod->num_ftrace_callsites); + if (ret) + pr_warn("ftrace: failed to allocate entries for module '%s' functions\n", + mod->name); } static void save_ftrace_mod_rec(struct ftrace_mod_map *mod_map, @@ -7096,6 +7268,8 @@ void __init ftrace_free_init_mem(void) void *start = (void *)(&__init_begin); void *end = (void *)(&__init_end); + ftrace_boot_snapshot(); + ftrace_free_mem(NULL, start, end); } @@ -7126,15 +7300,19 @@ void __init ftrace_init(void) pr_info("ftrace: allocating %ld entries in %ld pages\n", count, count / ENTRIES_PER_PAGE + 1); - last_ftrace_enabled = ftrace_enabled = 1; - ret = ftrace_process_locs(NULL, __start_mcount_loc, __stop_mcount_loc); + if (ret) { + pr_warn("ftrace: failed to allocate entries for functions\n"); + goto failed; + } pr_info("ftrace: allocated %ld pages with %ld groups\n", ftrace_number_of_pages, ftrace_number_of_groups); + last_ftrace_enabled = ftrace_enabled = 1; + set_ftrace_early_filters(); return; @@ -7193,9 +7371,6 @@ core_initcall(ftrace_nodyn_init); static inline int ftrace_init_dyn_tracefs(struct dentry *d_tracer) { return 0; } static inline void ftrace_startup_all(int command) { } -# define ftrace_startup_sysctl() do { } while (0) -# define ftrace_shutdown_sysctl() do { } while (0) - static void ftrace_update_trampoline(struct ftrace_ops *ops) { } @@ -7346,7 +7521,9 @@ ftrace_func_t ftrace_ops_get_func(struct ftrace_ops *ops) static void ftrace_filter_pid_sched_switch_probe(void *data, bool preempt, - struct task_struct *prev, struct task_struct *next) + struct task_struct *prev, + struct task_struct *next, + unsigned int prev_state) { struct trace_array *tr = data; struct trace_pid_list *pid_list; @@ -7833,6 +8010,118 @@ int unregister_ftrace_function(struct ftrace_ops *ops) } EXPORT_SYMBOL_GPL(unregister_ftrace_function); +static int symbols_cmp(const void *a, const void *b) +{ + const char **str_a = (const char **) a; + const char **str_b = (const char **) b; + + return strcmp(*str_a, *str_b); +} + +struct kallsyms_data { + unsigned long *addrs; + const char **syms; + size_t cnt; + size_t found; +}; + +static int kallsyms_callback(void *data, const char *name, + struct module *mod, unsigned long addr) +{ + struct kallsyms_data *args = data; + const char **sym; + int idx; + + sym = bsearch(&name, args->syms, args->cnt, sizeof(*args->syms), symbols_cmp); + if (!sym) + return 0; + + idx = sym - args->syms; + if (args->addrs[idx]) + return 0; + + addr = ftrace_location(addr); + if (!addr) + return 0; + + args->addrs[idx] = addr; + args->found++; + return args->found == args->cnt ? 1 : 0; +} + +/** + * ftrace_lookup_symbols - Lookup addresses for array of symbols + * + * @sorted_syms: array of symbols pointers symbols to resolve, + * must be alphabetically sorted + * @cnt: number of symbols/addresses in @syms/@addrs arrays + * @addrs: array for storing resulting addresses + * + * This function looks up addresses for array of symbols provided in + * @syms array (must be alphabetically sorted) and stores them in + * @addrs array, which needs to be big enough to store at least @cnt + * addresses. + * + * This function returns 0 if all provided symbols are found, + * -ESRCH otherwise. + */ +int ftrace_lookup_symbols(const char **sorted_syms, size_t cnt, unsigned long *addrs) +{ + struct kallsyms_data args; + int err; + + 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; +} + +#ifdef CONFIG_SYSCTL + +#ifdef CONFIG_DYNAMIC_FTRACE +static void ftrace_startup_sysctl(void) +{ + int command; + + if (unlikely(ftrace_disabled)) + return; + + /* Force update next time */ + saved_ftrace_func = NULL; + /* ftrace_start_up is true if we want ftrace running */ + if (ftrace_start_up) { + command = FTRACE_UPDATE_CALLS; + if (ftrace_graph_active) + command |= FTRACE_START_FUNC_RET; + ftrace_startup_enable(command); + } +} + +static void ftrace_shutdown_sysctl(void) +{ + int command; + + if (unlikely(ftrace_disabled)) + return; + + /* ftrace_start_up is true if ftrace is running */ + if (ftrace_start_up) { + command = FTRACE_DISABLE_CALLS; + if (ftrace_graph_active) + command |= FTRACE_STOP_FUNC_RET; + ftrace_run_update_code(command); + } +} +#else +# define ftrace_startup_sysctl() do { } while (0) +# define ftrace_shutdown_sysctl() do { } while (0) +#endif /* CONFIG_DYNAMIC_FTRACE */ + static bool is_permanent_ops_registered(void) { struct ftrace_ops *op; @@ -7845,7 +8134,7 @@ static bool is_permanent_ops_registered(void) return false; } -int +static int ftrace_enable_sysctl(struct ctl_table *table, int write, void *buffer, size_t *lenp, loff_t *ppos) { @@ -7888,3 +8177,22 @@ ftrace_enable_sysctl(struct ctl_table *table, int write, mutex_unlock(&ftrace_lock); return ret; } + +static struct ctl_table ftrace_sysctls[] = { + { + .procname = "ftrace_enabled", + .data = &ftrace_enabled, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = ftrace_enable_sysctl, + }, + {} +}; + +static int __init ftrace_sysctl_init(void) +{ + register_sysctl_init("kernel", ftrace_sysctls); + return 0; +} +late_initcall(ftrace_sysctl_init); +#endif |