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authorLinus Torvalds <torvalds@linux-foundation.org>2017-09-20 06:38:07 -1000
committerLinus Torvalds <torvalds@linux-foundation.org>2017-09-20 06:38:07 -1000
commitc52f56a69d104d5294af3d652776d94b1ef6a175 (patch)
tree5c4014d8b4b05668dbfb98b90fce0c41e839987f /kernel
parent820bf5c419e4b85298e5c3001bd1b5be46d60765 (diff)
parent75df6e688ccd517e339a7c422ef7ad73045b18a2 (diff)
download96b-common-c52f56a69d104d5294af3d652776d94b1ef6a175.tar.gz
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
Diffstat (limited to 'kernel')
-rw-r--r--kernel/trace/trace.c19
-rw-r--r--kernel/trace/trace.h2
-rw-r--r--kernel/trace/trace_mmiotrace.c1
3 files changed, 19 insertions, 3 deletions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 5360b7aec57a..752e5daf0896 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -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);
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index fb5d54d0d1b3..652c682707cd 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -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;
};
diff --git a/kernel/trace/trace_mmiotrace.c b/kernel/trace/trace_mmiotrace.c
index cd7480d0a201..dca78fc48439 100644
--- a/kernel/trace/trace_mmiotrace.c
+++ b/kernel/trace/trace_mmiotrace.c
@@ -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)