Commit c52f56a6 authored by Linus Torvalds's avatar Linus Torvalds

Merge tag 'trace-v4.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fixes from Steven Rostedt:
 "This includes three minor fixes.

    - Have writing to trace file clear the irqsoff (and friends) tracer

    - trace_pipe behavior for instance buffers was different than top
      buffer

    - Show a message of why mmiotrace doesn't start from commandline"

* tag 'trace-v4.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Fix trace_pipe behavior for instance traces
  tracing: Ignore mmiotrace from kernel commandline
  tracing: Erase irqsoff trace with empty write
parents 820bf5c4 75df6e68
......@@ -4020,11 +4020,17 @@ static int tracing_open(struct inode *inode, struct file *file)
/* If this file was open for write, then erase contents */
if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) {
int cpu = tracing_get_cpu(inode);
struct trace_buffer *trace_buf = &tr->trace_buffer;
#ifdef CONFIG_TRACER_MAX_TRACE
if (tr->current_trace->print_max)
trace_buf = &tr->max_buffer;
#endif
if (cpu == RING_BUFFER_ALL_CPUS)
tracing_reset_online_cpus(&tr->trace_buffer);
tracing_reset_online_cpus(trace_buf);
else
tracing_reset(&tr->trace_buffer, cpu);
tracing_reset(trace_buf, cpu);
}
if (file->f_mode & FMODE_READ) {
......@@ -5358,6 +5364,13 @@ static int tracing_set_tracer(struct trace_array *tr, const char *buf)
if (t == tr->current_trace)
goto out;
/* Some tracers won't work on kernel command line */
if (system_state < SYSTEM_RUNNING && t->noboot) {
pr_warn("Tracer '%s' is not allowed on command line, ignored\n",
t->name);
goto out;
}
/* Some tracers are only allowed for the top level buffer */
if (!trace_ok_for_array(t, tr)) {
ret = -EINVAL;
......@@ -5667,7 +5680,7 @@ static int tracing_wait_pipe(struct file *filp)
*
* iter->pos will be 0 if we haven't read anything.
*/
if (!tracing_is_on() && iter->pos)
if (!tracer_tracing_is_on(iter->tr) && iter->pos)
break;
mutex_unlock(&iter->mutex);
......
......@@ -444,6 +444,8 @@ struct tracer {
#ifdef CONFIG_TRACER_MAX_TRACE
bool use_max_tr;
#endif
/* True if tracer cannot be enabled in kernel param */
bool noboot;
};
......
......@@ -282,6 +282,7 @@ static struct tracer mmio_tracer __read_mostly =
.close = mmio_close,
.read = mmio_read,
.print_line = mmio_print_line,
.noboot = true,
};
__init static int init_mmio_trace(void)
......
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