diff options
Diffstat (limited to 'kernel/trace/trace.c')
| -rw-r--r-- | kernel/trace/trace.c | 299 |
1 files changed, 235 insertions, 64 deletions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index e5df02c69b1..a3f1bc5d2a0 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -338,10 +338,11 @@ static DECLARE_WAIT_QUEUE_HEAD(trace_wait); /* trace_flags holds trace_options default values */ unsigned long trace_flags = TRACE_ITER_PRINT_PARENT | TRACE_ITER_PRINTK | TRACE_ITER_ANNOTATE | TRACE_ITER_CONTEXT_INFO | TRACE_ITER_SLEEP_TIME | - TRACE_ITER_GRAPH_TIME | TRACE_ITER_RECORD_CMD | TRACE_ITER_OVERWRITE; + TRACE_ITER_GRAPH_TIME | TRACE_ITER_RECORD_CMD | TRACE_ITER_OVERWRITE | + TRACE_ITER_IRQ_INFO; static int trace_stop_count; -static DEFINE_SPINLOCK(tracing_start_lock); +static DEFINE_RAW_SPINLOCK(tracing_start_lock); static void wakeup_work_handler(struct work_struct *work) { @@ -426,6 +427,7 @@ static const char *trace_options[] = { "record-cmd", "overwrite", "disable_on_free", + "irq-info", NULL }; @@ -435,6 +437,7 @@ static struct { } trace_clocks[] = { { trace_clock_local, "local" }, { trace_clock_global, "global" }, + { trace_clock_counter, "counter" }, }; int trace_clock_id; @@ -960,7 +963,7 @@ void tracing_start(void) if (tracing_disabled) return; - spin_lock_irqsave(&tracing_start_lock, flags); + raw_spin_lock_irqsave(&tracing_start_lock, flags); if (--trace_stop_count) { if (trace_stop_count < 0) { /* Someone screwed up their debugging */ @@ -985,7 +988,7 @@ void tracing_start(void) ftrace_start(); out: - spin_unlock_irqrestore(&tracing_start_lock, flags); + raw_spin_unlock_irqrestore(&tracing_start_lock, flags); } /** @@ -1000,7 +1003,7 @@ void tracing_stop(void) unsigned long flags; ftrace_stop(); - spin_lock_irqsave(&tracing_start_lock, flags); + raw_spin_lock_irqsave(&tracing_start_lock, flags); if (trace_stop_count++) goto out; @@ -1018,7 +1021,7 @@ void tracing_stop(void) arch_spin_unlock(&ftrace_max_lock); out: - spin_unlock_irqrestore(&tracing_start_lock, flags); + raw_spin_unlock_irqrestore(&tracing_start_lock, flags); } void trace_stop_cmdline_recording(void); @@ -1842,6 +1845,33 @@ static void s_stop(struct seq_file *m, void *p) trace_event_read_unlock(); } +static void +get_total_entries(struct trace_array *tr, unsigned long *total, unsigned long *entries) +{ + unsigned long count; + int cpu; + + *total = 0; + *entries = 0; + + for_each_tracing_cpu(cpu) { + count = ring_buffer_entries_cpu(tr->buffer, cpu); + /* + * If this buffer has skipped entries, then we hold all + * entries for the trace and we need to ignore the + * ones before the time stamp. + */ + if (tr->data[cpu]->skipped_entries) { + count -= tr->data[cpu]->skipped_entries; + /* total is the same as the entries */ + *total += count; + } else + *total += count + + ring_buffer_overrun_cpu(tr->buffer, cpu); + *entries += count; + } +} + static void print_lat_help_header(struct seq_file *m) { seq_puts(m, "# _------=> CPU# \n"); @@ -1854,12 +1884,35 @@ static void print_lat_help_header(struct seq_file *m) seq_puts(m, "# \\ / ||||| \\ | / \n"); } -static void print_func_help_header(struct seq_file *m) +static void print_event_info(struct trace_array *tr, struct seq_file *m) +{ + unsigned long total; + unsigned long entries; + + get_total_entries(tr, &total, &entries); + seq_printf(m, "# entries-in-buffer/entries-written: %lu/%lu #P:%d\n", + entries, total, num_online_cpus()); + seq_puts(m, "#\n"); +} + +static void print_func_help_header(struct trace_array *tr, struct seq_file *m) { - seq_puts(m, "# TASK-PID CPU# TIMESTAMP FUNCTION\n"); + print_event_info(tr, m); + seq_puts(m, "# TASK-PID CPU# TIMESTAMP FUNCTION\n"); seq_puts(m, "# | | | | |\n"); } +static void print_func_help_header_irq(struct trace_array *tr, struct seq_file *m) +{ + print_event_info(tr, m); + seq_puts(m, "# _-----=> irqs-off\n"); + seq_puts(m, "# / _----=> need-resched\n"); + seq_puts(m, "# | / _---=> hardirq/softirq\n"); + seq_puts(m, "# || / _--=> preempt-depth\n"); + seq_puts(m, "# ||| / delay\n"); + seq_puts(m, "# TASK-PID CPU# |||| TIMESTAMP FUNCTION\n"); + seq_puts(m, "# | | | |||| | |\n"); +} void print_trace_header(struct seq_file *m, struct trace_iterator *iter) @@ -1868,32 +1921,14 @@ print_trace_header(struct seq_file *m, struct trace_iterator *iter) struct trace_array *tr = iter->tr; struct trace_array_cpu *data = tr->data[tr->cpu]; struct tracer *type = current_trace; - unsigned long entries = 0; - unsigned long total = 0; - unsigned long count; + unsigned long entries; + unsigned long total; const char *name = "preemption"; - int cpu; if (type) name = type->name; - - for_each_tracing_cpu(cpu) { - count = ring_buffer_entries_cpu(tr->buffer, cpu); - /* - * If this buffer has skipped entries, then we hold all - * entries for the trace and we need to ignore the - * ones before the time stamp. - */ - if (tr->data[cpu]->skipped_entries) { - count -= tr->data[cpu]->skipped_entries; - /* total is the same as the entries */ - total += count; - } else - total += count + - ring_buffer_overrun_cpu(tr->buffer, cpu); - entries += count; - } + get_total_entries(tr, &total, &entries); seq_printf(m, "# %s latency trace v1.1.5 on %s\n", name, UTS_RELEASE); @@ -2139,6 +2174,21 @@ enum print_line_t print_trace_line(struct trace_iterator *iter) return print_trace_fmt(iter); } +void trace_latency_header(struct seq_file *m) +{ + struct trace_iterator *iter = m->private; + + /* print nothing if the buffers are empty */ + if (trace_empty(iter)) + return; + + if (iter->iter_flags & TRACE_FILE_LAT_FMT) + print_trace_header(m, iter); + + if (!(trace_flags & TRACE_ITER_VERBOSE)) + print_lat_help_header(m); +} + void trace_default_header(struct seq_file *m) { struct trace_iterator *iter = m->private; @@ -2154,11 +2204,23 @@ void trace_default_header(struct seq_file *m) if (!(trace_flags & TRACE_ITER_VERBOSE)) print_lat_help_header(m); } else { - if (!(trace_flags & TRACE_ITER_VERBOSE)) - print_func_help_header(m); + if (!(trace_flags & TRACE_ITER_VERBOSE)) { + if (trace_flags & TRACE_ITER_IRQ_INFO) + print_func_help_header_irq(iter->tr, m); + else + print_func_help_header(iter->tr, m); + } } } +static void test_ftrace_alive(struct seq_file *m) +{ + if (!ftrace_is_dead()) + return; + seq_printf(m, "# WARNING: FUNCTION TRACING IS CORRUPTED\n"); + seq_printf(m, "# MAY BE MISSING FUNCTION EVENTS\n"); +} + static int s_show(struct seq_file *m, void *v) { struct trace_iterator *iter = v; @@ -2168,6 +2230,7 @@ static int s_show(struct seq_file *m, void *v) if (iter->tr) { seq_printf(m, "# tracer: %s\n", iter->trace->name); seq_puts(m, "#\n"); + test_ftrace_alive(m); } if (iter->trace && iter->trace->print_header) iter->trace->print_header(m); @@ -2710,9 +2773,9 @@ static const char readme_msg[] = "# cat /sys/kernel/debug/tracing/trace_options\n" "noprint-parent nosym-offset nosym-addr noverbose\n" "# echo print-parent > /sys/kernel/debug/tracing/trace_options\n" - "# echo 1 > /sys/kernel/debug/tracing/tracing_enabled\n" + "# echo 1 > /sys/kernel/debug/tracing/tracing_on\n" "# cat /sys/kernel/debug/tracing/trace > /tmp/trace.txt\n" - "# echo 0 > /sys/kernel/debug/tracing/tracing_enabled\n" + "# echo 0 > /sys/kernel/debug/tracing/tracing_on\n" ; static ssize_t @@ -3569,6 +3632,30 @@ tracing_entries_write(struct file *filp, const char __user *ubuf, } static ssize_t +tracing_total_entries_read(struct file *filp, char __user *ubuf, + size_t cnt, loff_t *ppos) +{ + struct trace_array *tr = filp->private_data; + char buf[64]; + int r, cpu; + unsigned long size = 0, expanded_size = 0; + + mutex_lock(&trace_types_lock); + for_each_tracing_cpu(cpu) { + size += tr->entries >> 10; + if (!ring_buffer_expanded) + expanded_size += trace_buf_size >> 10; + } + if (ring_buffer_expanded) + r = sprintf(buf, "%lu\n", size); + else + r = sprintf(buf, "%lu (expanded: %lu)\n", size, expanded_size); + mutex_unlock(&trace_types_lock); + + return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); +} + +static ssize_t tracing_free_buffer_write(struct file *filp, const char __user *ubuf, size_t cnt, loff_t *ppos) { @@ -3594,22 +3681,24 @@ tracing_free_buffer_release(struct inode *inode, struct file *filp) return 0; } -static int mark_printk(const char *fmt, ...) -{ - int ret; - va_list args; - va_start(args, fmt); - ret = trace_vprintk(0, fmt, args); - va_end(args); - return ret; -} - static ssize_t tracing_mark_write(struct file *filp, const char __user *ubuf, size_t cnt, loff_t *fpos) { - char *buf; - size_t written; + unsigned long addr = (unsigned long)ubuf; + struct ring_buffer_event *event; + struct ring_buffer *buffer; + struct print_entry *entry; + unsigned long irq_flags; + struct page *pages[2]; + int nr_pages = 1; + ssize_t written; + void *page1; + void *page2; + int offset; + int size; + int len; + int ret; if (tracing_disabled) return -EINVAL; @@ -3617,28 +3706,81 @@ tracing_mark_write(struct file *filp, const char __user *ubuf, if (cnt > TRACE_BUF_SIZE) cnt = TRACE_BUF_SIZE; - buf = kmalloc(cnt + 2, GFP_KERNEL); - if (buf == NULL) - return -ENOMEM; + /* + * Userspace is injecting traces into the kernel trace buffer. + * We want to be as non intrusive as possible. + * To do so, we do not want to allocate any special buffers + * or take any locks, but instead write the userspace data + * straight into the ring buffer. + * + * First we need to pin the userspace buffer into memory, + * which, most likely it is, because it just referenced it. + * But there's no guarantee that it is. By using get_user_pages_fast() + * and kmap_atomic/kunmap_atomic() we can get access to the + * pages directly. We then write the data directly into the + * ring buffer. + */ + BUILD_BUG_ON(TRACE_BUF_SIZE >= PAGE_SIZE); - if (copy_from_user(buf, ubuf, cnt)) { - kfree(buf); - return -EFAULT; + /* check if we cross pages */ + if ((addr & PAGE_MASK) != ((addr + cnt) & PAGE_MASK)) + nr_pages = 2; + + offset = addr & (PAGE_SIZE - 1); + addr &= PAGE_MASK; + + ret = get_user_pages_fast(addr, nr_pages, 0, pages); + if (ret < nr_pages) { + while (--ret >= 0) + put_page(pages[ret]); + written = -EFAULT; + goto out; } - if (buf[cnt-1] != '\n') { - buf[cnt] = '\n'; - buf[cnt+1] = '\0'; + + page1 = kmap_atomic(pages[0]); + if (nr_pages == 2) + page2 = kmap_atomic(pages[1]); + + local_save_flags(irq_flags); + size = sizeof(*entry) + cnt + 2; /* possible \n added */ + buffer = global_trace.buffer; + event = trace_buffer_lock_reserve(buffer, TRACE_PRINT, size, + irq_flags, preempt_count()); + if (!event) { + /* Ring buffer disabled, return as if not open for write */ + written = -EBADF; + goto out_unlock; + } + + entry = ring_buffer_event_data(event); + entry->ip = _THIS_IP_; + + if (nr_pages == 2) { + len = PAGE_SIZE - offset; + memcpy(&entry->buf, page1 + offset, len); + memcpy(&entry->buf[len], page2, cnt - len); } else - buf[cnt] = '\0'; + memcpy(&entry->buf, page1 + offset, cnt); - written = mark_printk("%s", buf); - kfree(buf); - *fpos += written; + if (entry->buf[cnt - 1] != '\n') { + entry->buf[cnt] = '\n'; + entry->buf[cnt + 1] = '\0'; + } else + entry->buf[cnt] = '\0'; + + ring_buffer_unlock_commit(buffer, event); + + written = cnt; - /* don't tell userspace we wrote more - it might confuse them */ - if (written > cnt) - written = cnt; + *fpos += written; + out_unlock: + if (nr_pages == 2) + kunmap_atomic(page2); + kunmap_atomic(page1); + while (nr_pages > 0) + put_page(pages[--nr_pages]); + out: return written; } @@ -3739,6 +3881,12 @@ static const struct file_operations tracing_entries_fops = { .llseek = generic_file_llseek, }; +static const struct file_operations tracing_total_entries_fops = { + .open = tracing_open_generic, + .read = tracing_total_entries_read, + .llseek = generic_file_llseek, +}; + static const struct file_operations tracing_free_buffer_fops = { .write = tracing_free_buffer_write, .release = tracing_free_buffer_release, @@ -3808,8 +3956,6 @@ tracing_buffers_read(struct file *filp, char __user *ubuf, if (info->read < PAGE_SIZE) goto read; - info->read = 0; - trace_access_lock(info->cpu); ret = ring_buffer_read_page(info->tr->buffer, &info->spare, @@ -3819,6 +3965,8 @@ tracing_buffers_read(struct file *filp, char __user *ubuf, if (ret < 0) return 0; + info->read = 0; + read: size = PAGE_SIZE - info->read; if (size > count) @@ -4026,6 +4174,8 @@ tracing_stats_read(struct file *filp, char __user *ubuf, struct trace_array *tr = &global_trace; struct trace_seq *s; unsigned long cnt; + unsigned long long t; + unsigned long usec_rem; s = kmalloc(sizeof(*s), GFP_KERNEL); if (!s) @@ -4042,6 +4192,17 @@ tracing_stats_read(struct file *filp, char __user *ubuf, cnt = ring_buffer_commit_overrun_cpu(tr->buffer, cpu); trace_seq_printf(s, "commit overrun: %ld\n", cnt); + cnt = ring_buffer_bytes_cpu(tr->buffer, cpu); + trace_seq_printf(s, "bytes: %ld\n", cnt); + + t = ns2usecs(ring_buffer_oldest_event_ts(tr->buffer, cpu)); + usec_rem = do_div(t, USEC_PER_SEC); + trace_seq_printf(s, "oldest event ts: %5llu.%06lu\n", t, usec_rem); + + t = ns2usecs(ring_buffer_time_stamp(tr->buffer, cpu)); + usec_rem = do_div(t, USEC_PER_SEC); + trace_seq_printf(s, "now ts: %5llu.%06lu\n", t, usec_rem); + count = simple_read_from_buffer(ubuf, count, ppos, s->buffer, s->len); kfree(s); @@ -4277,7 +4438,7 @@ static const struct file_operations trace_options_core_fops = { }; struct dentry *trace_create_file(const char *name, - mode_t mode, + umode_t mode, struct dentry *parent, void *data, const struct file_operations *fops) @@ -4450,6 +4611,9 @@ static __init int tracer_init_debugfs(void) trace_create_file("buffer_size_kb", 0644, d_tracer, &global_trace, &tracing_entries_fops); + trace_create_file("buffer_total_size_kb", 0444, d_tracer, + &global_trace, &tracing_total_entries_fops); + trace_create_file("free_buffer", 0644, d_tracer, &global_trace, &tracing_free_buffer_fops); @@ -4566,6 +4730,12 @@ __ftrace_dump(bool disable_tracing, enum ftrace_dump_mode oops_dump_mode) tracing_off(); + /* Did function tracer already get disabled? */ + if (ftrace_is_dead()) { + printk("# WARNING: FUNCTION TRACING IS CORRUPTED\n"); + printk("# MAY BE MISSING FUNCTION EVENTS\n"); + } + if (disable_tracing) ftrace_kill(); @@ -4658,6 +4828,7 @@ void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) { __ftrace_dump(true, oops_dump_mode); } +EXPORT_SYMBOL_GPL(ftrace_dump); __init static int tracer_alloc_buffers(void) { |