The patch below does not apply to the 4.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable@xxxxxxxxxxxxxxx>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 8f0994bb8cbde5452e58ce0cacdbf6cb58079d01 Mon Sep 17 00:00:00 2001 From: Wei Yongjun <weiyongjun1@xxxxxxxxxx> Date: Thu, 12 Jan 2017 13:55:02 +0000 Subject: [PATCH] tracing: Fix return value check in trace_benchmark_reg() In case of error, the function kthread_run() returns ERR_PTR() and never returns NULL. The NULL test in the return value check should be replaced with IS_ERR(). Link: http://lkml.kernel.org/r/20170112135502.28556-1-weiyj.lk@xxxxxxxxx Cc: stable@xxxxxxxxxxxxxxx Fixes: 81dc9f0e ("tracing: Add tracepoint benchmark tracepoint") Signed-off-by: Wei Yongjun <weiyongjun1@xxxxxxxxxx> Signed-off-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx> diff --git a/kernel/trace/trace_benchmark.c b/kernel/trace/trace_benchmark.c index e3b488825ae3..e49fbe901cfc 100644 --- a/kernel/trace/trace_benchmark.c +++ b/kernel/trace/trace_benchmark.c @@ -175,9 +175,9 @@ int trace_benchmark_reg(void) bm_event_thread = kthread_run(benchmark_event_kthread, NULL, "event_benchmark"); - if (!bm_event_thread) { + if (IS_ERR(bm_event_thread)) { pr_warning("trace benchmark failed to create kernel thread\n"); - return -ENOMEM; + return PTR_ERR(bm_event_thread); } return 0;