diff options
| author |   Ziqian SUN (Zamir) <zsun@redhat.com> | 2017-09-11 14:26:35 +0800 |
|---|---|---|
| committer |   Steven Rostedt (VMware) <rostedt@goodmis.org> | 2017-09-19 12:36:01 -0400 |
| commit | c7b3ae0bd2ca658c7a71c49901d08c590294fac9 (patch) | |
| tree | 6e33bb7c8a1a01d7c63b513129b1097d1ba73ae6 /kernel | |
| parent | tracing: Erase irqsoff trace with empty write (diff) | |
| download | linux-dev-c7b3ae0bd2ca658c7a71c49901d08c590294fac9.tar.xz linux-dev-c7b3ae0bd2ca658c7a71c49901d08c590294fac9.zip | |
tracing: Ignore mmiotrace from kernel commandline
The mmiotrace tracer cannot be enabled with ftrace=mmiotrace in kernel
commandline. With this patch, noboot is added to the tracer struct,
and when system boot with a tracer that has noboot=true, it will print
out a warning message and continue booting.
Link: http://lkml.kernel.org/r/1505111195-31942-1-git-send-email-zsun@redhat.com
Signed-off-by: Ziqian SUN (Zamir) <zsun@redhat.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/trace/trace.c | 7 | ||||
| -rw-r--r-- | kernel/trace/trace.h | 2 | ||||
| -rw-r--r-- | kernel/trace/trace_mmiotrace.c | 1 |
3 files changed, 10 insertions, 0 deletions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index a7fb136da891..d3ca35f38803 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -5364,6 +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; 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) |