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-rw-r--r--kernel/trace/trace.c173
1 files changed, 145 insertions, 28 deletions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index e5df02c69b1d..f86efe90ca45 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -435,6 +435,7 @@ static struct {
} trace_clocks[] = {
{ trace_clock_local, "local" },
{ trace_clock_global, "global" },
+ { trace_clock_counter, "counter" },
};
int trace_clock_id;
@@ -2159,6 +2160,14 @@ void trace_default_header(struct seq_file *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 +2177,7 @@ 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);
@@ -3569,6 +3579,30 @@ 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 +3628,24 @@ 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 +3653,81 @@ 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';
- /* don't tell userspace we wrote more - it might confuse them */
- if (written > cnt)
- written = cnt;
+ ring_buffer_unlock_commit(buffer, event);
+
+ 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 +3828,12 @@ 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,
@@ -4026,6 +4121,8 @@ 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 +4139,17 @@ 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);
@@ -4450,6 +4558,9 @@ 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 +4677,12 @@ __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();