From e07a1d576239cf836070e740d4bd7c5e8a64868f Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (VMware)" Date: Mon, 29 Nov 2021 21:39:46 -0500 Subject: [PATCH] tracing: Use __this_cpu_read() in trace_event_buffer_lock_reserver() The value read by this_cpu_read() is used later and its use is expected to stay on the same CPU as being read. But this_cpu_read() does not warn if it is called without preemption disabled, where as __this_cpu_read() will check if preemption is disabled on CONFIG_DEBUG_PREEMPT Currently all callers have preemption disabled, but there may be new callers in the future that may not. Link: https://lkml.kernel.org/r/20211130024318.698165354@goodmis.org Signed-off-by: Steven Rostedt (VMware) --- kernel/trace/trace.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 4821fe6a40a51..2e87b7bf2ba7f 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -2746,7 +2746,7 @@ trace_event_buffer_lock_reserve(struct trace_buffer **current_rb, if (!tr->no_filter_buffering_ref && (trace_file->flags & (EVENT_FILE_FL_SOFT_DISABLED | EVENT_FILE_FL_FILTERED)) && - (entry = this_cpu_read(trace_buffered_event))) { + (entry = __this_cpu_read(trace_buffered_event))) { /* * Filtering is on, so try to use the per cpu buffer first. * This buffer will simulate a ring_buffer_event, -- 2.30.2