From 48aa636a2e68c1632923f5de2f658ce156b4ee81 Mon Sep 17 00:00:00 2001 From: Nathan Chancellor Date: Wed, 19 Feb 2020 22:10:12 -0700 Subject: [PATCH] tracing: Use address-of operator on section symbols [ Upstream commit bf2cbe044da275021b2de5917240411a19e5c50d ] Clang warns: ../kernel/trace/trace.c:9335:33: warning: array comparison always evaluates to true [-Wtautological-compare] if (__stop___trace_bprintk_fmt != __start___trace_bprintk_fmt) ^ 1 warning generated. These are not true arrays, they are linker defined symbols, which are just addresses. Using the address of operator silences the warning and does not change the runtime result of the check (tested with some print statements compiled in with clang + ld.lld and gcc + ld.bfd in QEMU). Link: http://lkml.kernel.org/r/20200220051011.26113-1-natechancellor@gmail.com Link: https://github.com/ClangBuiltLinux/linux/issues/893 Suggested-by: Nick Desaulniers Signed-off-by: Nathan Chancellor Signed-off-by: Steven Rostedt (VMware) Signed-off-by: Sasha Levin --- 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 17ea5f9d36b48..e4a0c0308b507 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -7263,7 +7263,7 @@ __init static int tracer_alloc_buffers(void) goto out_free_buffer_mask; /* Only allocate trace_printk buffers if a trace_printk exists */ - if (__stop___trace_bprintk_fmt != __start___trace_bprintk_fmt) + if (&__stop___trace_bprintk_fmt != &__start___trace_bprintk_fmt) /* Must be called before global_trace.buffer is allocated */ trace_printk_init_buffers(); -- 2.47.2