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authorAnton Vorontsov <anton.vorontsov@linaro.org>2012-07-09 17:10:39 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2012-07-17 09:50:53 -0700
commitb2ad368bebc0f772613668e893fa176396e9094c (patch)
treef2c14b8eea287afdab9eb5eba59792e1048b212a /kernel/trace
parentc1743cbc8d20d208bb1d2b10598204f2d89b144c (diff)
downloadlinux-b2ad368bebc0f772613668e893fa176396e9094c.tar.bz2
tracing: Fix initialization failure path in tracing_set_tracer()
If tracer->init() fails, current code will leave current_tracer pointing to an unusable tracer, which at best makes 'current_tracer' report inaccurate value. Fix the issue by pointing current_tracer to nop tracer, and only update current_tracer with the new one after all the initialization succeeds. Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org> Acked-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'kernel/trace')
-rw-r--r--kernel/trace/trace.c7
1 files changed, 4 insertions, 3 deletions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 49249c28690d..44ee11e31b82 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -3172,10 +3172,10 @@ static int tracing_set_tracer(const char *buf)
}
destroy_trace_option_files(topts);
- current_trace = t;
+ current_trace = &nop_trace;
- topts = create_trace_option_files(current_trace);
- if (current_trace->use_max_tr) {
+ topts = create_trace_option_files(t);
+ if (t->use_max_tr) {
int cpu;
/* we need to make per cpu buffer sizes equivalent */
for_each_tracing_cpu(cpu) {
@@ -3195,6 +3195,7 @@ static int tracing_set_tracer(const char *buf)
goto out;
}
+ current_trace = t;
trace_branch_enable(tr);
out:
mutex_unlock(&trace_types_lock);