diff options
Diffstat (limited to 'kernel/trace/trace_events.c')
| -rw-r--r-- | kernel/trace/trace_events.c | 126 |
1 files changed, 104 insertions, 22 deletions
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index 0cc51edde3a8..b03a0ea77b99 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -212,8 +212,40 @@ void *ftrace_event_buffer_reserve(struct ftrace_event_buffer *fbuffer, } EXPORT_SYMBOL_GPL(ftrace_event_buffer_reserve); +static DEFINE_SPINLOCK(tracepoint_iter_lock); + +static void output_printk(struct ftrace_event_buffer *fbuffer) +{ + struct ftrace_event_call *event_call; + struct trace_event *event; + unsigned long flags; + struct trace_iterator *iter = tracepoint_print_iter; + + if (!iter) + return; + + event_call = fbuffer->ftrace_file->event_call; + if (!event_call || !event_call->event.funcs || + !event_call->event.funcs->trace) + return; + + event = &fbuffer->ftrace_file->event_call->event; + + spin_lock_irqsave(&tracepoint_iter_lock, flags); + trace_seq_init(&iter->seq); + iter->ent = fbuffer->entry; + event_call->event.funcs->trace(iter, 0, event); + trace_seq_putc(&iter->seq, 0); + printk("%s", iter->seq.buffer); + + spin_unlock_irqrestore(&tracepoint_iter_lock, flags); +} + void ftrace_event_buffer_commit(struct ftrace_event_buffer *fbuffer) { + if (tracepoint_printk) + output_printk(fbuffer); + event_trigger_unlock_commit(fbuffer->ftrace_file, fbuffer->buffer, fbuffer->event, fbuffer->entry, fbuffer->flags, fbuffer->pc); @@ -461,7 +493,7 @@ static void remove_event_file_dir(struct ftrace_event_file *file) if (dir) { spin_lock(&dir->d_lock); /* probably unneeded */ - list_for_each_entry(child, &dir->d_subdirs, d_u.d_child) { + list_for_each_entry(child, &dir->d_subdirs, d_child) { if (child->d_inode) /* probably unneeded */ child->d_inode->i_private = NULL; } @@ -918,7 +950,7 @@ static int f_show(struct seq_file *m, void *v) case FORMAT_HEADER: seq_printf(m, "name: %s\n", ftrace_event_name(call)); seq_printf(m, "ID: %d\n", call->event.type); - seq_printf(m, "format:\n"); + seq_puts(m, "format:\n"); return 0; case FORMAT_FIELD_SEPERATOR: @@ -1044,7 +1076,8 @@ event_filter_read(struct file *filp, char __user *ubuf, size_t cnt, mutex_unlock(&event_mutex); if (file) - r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len); + r = simple_read_from_buffer(ubuf, cnt, ppos, + s->buffer, trace_seq_used(s)); kfree(s); @@ -1210,7 +1243,8 @@ subsystem_filter_read(struct file *filp, char __user *ubuf, size_t cnt, trace_seq_init(s); print_subsystem_event_filter(system, s); - r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len); + r = simple_read_from_buffer(ubuf, cnt, ppos, + s->buffer, trace_seq_used(s)); kfree(s); @@ -1265,7 +1299,8 @@ show_header(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos) trace_seq_init(s); func(s); - r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len); + r = simple_read_from_buffer(ubuf, cnt, ppos, + s->buffer, trace_seq_used(s)); kfree(s); @@ -1988,7 +2023,7 @@ event_enable_print(struct seq_file *m, unsigned long ip, ftrace_event_name(data->file->event_call)); if (data->count == -1) - seq_printf(m, ":unlimited\n"); + seq_puts(m, ":unlimited\n"); else seq_printf(m, ":count=%ld\n", data->count); @@ -2394,12 +2429,39 @@ static __init int event_trace_memsetup(void) return 0; } +static __init void +early_enable_events(struct trace_array *tr, bool disable_first) +{ + char *buf = bootup_event_buf; + char *token; + int ret; + + while (true) { + token = strsep(&buf, ","); + + if (!token) + break; + if (!*token) + continue; + + /* Restarting syscalls requires that we stop them first */ + if (disable_first) + ftrace_set_clr_event(tr, token, 0); + + ret = ftrace_set_clr_event(tr, token, 1); + if (ret) + pr_warn("Failed to enable trace event: %s\n", token); + + /* Put back the comma to allow this to be called again */ + if (buf) + *(buf - 1) = ','; + } +} + static __init int event_trace_enable(void) { struct trace_array *tr = top_trace_array(); struct ftrace_event_call **iter, *call; - char *buf = bootup_event_buf; - char *token; int ret; if (!tr) @@ -2421,18 +2483,7 @@ static __init int event_trace_enable(void) */ __trace_early_add_events(tr); - while (true) { - token = strsep(&buf, ","); - - if (!token) - break; - if (!*token) - continue; - - ret = ftrace_set_clr_event(tr, token, 1); - if (ret) - pr_warn("Failed to enable trace event: %s\n", token); - } + early_enable_events(tr, false); trace_printk_start_comm(); @@ -2443,6 +2494,31 @@ static __init int event_trace_enable(void) return 0; } +/* + * event_trace_enable() is called from trace_event_init() first to + * initialize events and perhaps start any events that are on the + * command line. Unfortunately, there are some events that will not + * start this early, like the system call tracepoints that need + * to set the TIF_SYSCALL_TRACEPOINT flag of pid 1. But event_trace_enable() + * is called before pid 1 starts, and this flag is never set, making + * the syscall tracepoint never get reached, but the event is enabled + * regardless (and not doing anything). + */ +static __init int event_trace_enable_again(void) +{ + struct trace_array *tr; + + tr = top_trace_array(); + if (!tr) + return -ENODEV; + + early_enable_events(tr, true); + + return 0; +} + +early_initcall(event_trace_enable_again); + static __init int event_trace_init(void) { struct trace_array *tr; @@ -2477,8 +2553,14 @@ static __init int event_trace_init(void) #endif return 0; } -early_initcall(event_trace_memsetup); -core_initcall(event_trace_enable); + +void __init trace_event_init(void) +{ + event_trace_memsetup(); + init_ftrace_syscalls(); + event_trace_enable(); +} + fs_initcall(event_trace_init); #ifdef CONFIG_FTRACE_STARTUP_TEST |