diff --git a/drivers/scsi/qla2xxx/qla_os.c b/drivers/scsi/qla2xxx/qla_os.c index 03348f605c2e..dd674378f2f3 100644 --- a/drivers/scsi/qla2xxx/qla_os.c +++ b/drivers/scsi/qla2xxx/qla_os.c @@ -2889,7 +2889,7 @@ static void qla2x00_iocb_work_fn(struct work_struct *work) static void qla_trace_init(void) { - qla_trc_array = trace_array_get_by_name("qla2xxx"); + qla_trc_array = trace_array_get_by_name("qla2xxx", NULL); if (!qla_trc_array) { ql_log(ql_log_fatal, NULL, 0x0001, "Unable to create qla2xxx trace instance, instance logging will be disabled.\n"); diff --git a/include/linux/trace.h b/include/linux/trace.h index 2a70a447184c..fdcd76b7be83 100644 --- a/include/linux/trace.h +++ b/include/linux/trace.h @@ -51,7 +51,7 @@ int trace_array_printk(struct trace_array *tr, unsigned long ip, const char *fmt, ...); int trace_array_init_printk(struct trace_array *tr); void trace_array_put(struct trace_array *tr); -struct trace_array *trace_array_get_by_name(const char *name); +struct trace_array *trace_array_get_by_name(const char *name, const char *systems); int trace_array_destroy(struct trace_array *tr); /* For osnoise tracer */ @@ -84,7 +84,7 @@ static inline int trace_array_init_printk(struct trace_array *tr) static inline void trace_array_put(struct trace_array *tr) { } -static inline struct trace_array *trace_array_get_by_name(const char *name) +static inline struct trace_array *trace_array_get_by_name(const char *name, const char *systems) { return NULL; } diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 199df497db07..59e39b652afb 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -9490,7 +9490,8 @@ static int trace_array_create_dir(struct trace_array *tr) return ret; } -static struct trace_array *trace_array_create(const char *name) +static struct trace_array * +trace_array_create_systems(const char *name, const char *systems) { struct trace_array *tr; int ret; @@ -9510,6 +9511,12 @@ static struct trace_array *trace_array_create(const char *name) if (!zalloc_cpumask_var(&tr->pipe_cpumask, GFP_KERNEL)) goto out_free_tr; + if (systems) { + tr->system_names = kstrdup_const(systems, GFP_KERNEL); + if (!tr->system_names) + goto out_free_tr; + } + tr->trace_flags = global_trace.trace_flags & ~ZEROED_TRACE_FLAGS; cpumask_copy(tr->tracing_cpumask, cpu_all_mask); @@ -9556,12 +9563,18 @@ static struct trace_array *trace_array_create(const char *name) free_trace_buffers(tr); free_cpumask_var(tr->pipe_cpumask); free_cpumask_var(tr->tracing_cpumask); + kfree_const(tr->system_names); kfree(tr->name); kfree(tr); return ERR_PTR(ret); } +static struct trace_array *trace_array_create(const char *name) +{ + return trace_array_create_systems(name, NULL); +} + static int instance_mkdir(const char *name) { struct trace_array *tr; @@ -9587,6 +9600,7 @@ out_unlock: /** * trace_array_get_by_name - Create/Lookup a trace array, given its name. * @name: The name of the trace array to be looked up/created. + * @systems: A list of systems to create event directories for (NULL for all) * * Returns pointer to trace array with given name. * NULL, if it cannot be created. @@ -9600,7 +9614,7 @@ out_unlock: * trace_array_put() is called, user space can not delete it. * */ -struct trace_array *trace_array_get_by_name(const char *name) +struct trace_array *trace_array_get_by_name(const char *name, const char *systems) { struct trace_array *tr; @@ -9612,7 +9626,7 @@ struct trace_array *trace_array_get_by_name(const char *name) goto out_unlock; } - tr = trace_array_create(name); + tr = trace_array_create_systems(name, systems); if (IS_ERR(tr)) tr = NULL; @@ -9659,6 +9673,7 @@ static int __remove_instance(struct trace_array *tr) free_cpumask_var(tr->pipe_cpumask); free_cpumask_var(tr->tracing_cpumask); + kfree_const(tr->system_names); kfree(tr->name); kfree(tr); @@ -10377,7 +10392,7 @@ __init static void enable_instances(void) if (IS_ENABLED(CONFIG_TRACER_MAX_TRACE)) do_allocate_snapshot(tok); - tr = trace_array_get_by_name(tok); + tr = trace_array_get_by_name(tok, NULL); if (!tr) { pr_warn("Failed to create instance buffer %s\n", curr_str); continue; diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 0489e72c8169..79180aed13ee 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -377,6 +377,7 @@ struct trace_array { unsigned char trace_flags_index[TRACE_FLAGS_MAX_SIZE]; unsigned int flags; raw_spinlock_t start_lock; + const char *system_names; struct list_head err_log; struct dentry *dir; struct dentry *options; diff --git a/kernel/trace/trace_boot.c b/kernel/trace/trace_boot.c index 7ccc7a8e155b..dbe29b4c6a7a 100644 --- a/kernel/trace/trace_boot.c +++ b/kernel/trace/trace_boot.c @@ -633,7 +633,7 @@ trace_boot_init_instances(struct xbc_node *node) if (!p || *p == '\0') continue; - tr = trace_array_get_by_name(p); + tr = trace_array_get_by_name(p, NULL); if (!tr) { pr_err("Failed to get trace instance %s\n", p); continue; diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index f29e815ca5b2..b70d03818038 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -2896,6 +2896,27 @@ void trace_event_eval_update(struct trace_eval_map **map, int len) up_write(&trace_event_sem); } +static bool event_in_systems(struct trace_event_call *call, + const char *systems) +{ + const char *system; + const char *p; + + if (!systems) + return true; + + system = call->class->system; + p = strstr(systems, system); + if (!p) + return false; + + if (p != systems && !isspace(*(p - 1)) && *(p - 1) != ',') + return false; + + p += strlen(system); + return !*p || isspace(*p) || *p == ','; +} + static struct trace_event_file * trace_create_new_event(struct trace_event_call *call, struct trace_array *tr) @@ -2905,9 +2926,12 @@ trace_create_new_event(struct trace_event_call *call, struct trace_event_file *file; unsigned int first; + if (!event_in_systems(call, tr->system_names)) + return NULL; + file = kmem_cache_alloc(file_cachep, GFP_TRACE); if (!file) - return NULL; + return ERR_PTR(-ENOMEM); pid_list = rcu_dereference_protected(tr->filtered_pids, lockdep_is_held(&event_mutex)); @@ -2972,8 +2996,17 @@ __trace_add_new_event(struct trace_event_call *call, struct trace_array *tr) struct trace_event_file *file; file = trace_create_new_event(call, tr); + /* + * trace_create_new_event() returns ERR_PTR(-ENOMEM) if failed + * allocation, or NULL if the event is not part of the tr->system_names. + * When the event is not part of the tr->system_names, return zero, not + * an error. + */ if (!file) - return -ENOMEM; + return 0; + + if (IS_ERR(file)) + return PTR_ERR(file); if (eventdir_initialized) return event_create_dir(tr->event_dir, file); @@ -3012,8 +3045,17 @@ __trace_early_add_new_event(struct trace_event_call *call, int ret; file = trace_create_new_event(call, tr); + /* + * trace_create_new_event() returns ERR_PTR(-ENOMEM) if failed + * allocation, or NULL if the event is not part of the tr->system_names. + * When the event is not part of the tr->system_names, return zero, not + * an error. + */ if (!file) - return -ENOMEM; + return 0; + + if (IS_ERR(file)) + return PTR_ERR(file); ret = event_define_fields(call); if (ret) diff --git a/samples/ftrace/sample-trace-array.c b/samples/ftrace/sample-trace-array.c index 6aba02a31c96..d0ee9001c7b3 100644 --- a/samples/ftrace/sample-trace-array.c +++ b/samples/ftrace/sample-trace-array.c @@ -105,7 +105,7 @@ static int __init sample_trace_array_init(void) * NOTE: This function increments the reference counter * associated with the trace array - "tr". */ - tr = trace_array_get_by_name("sample-instance"); + tr = trace_array_get_by_name("sample-instance", "sched,timer,kprobes"); if (!tr) return -1;