On Tue, 18 Feb 2020 21:54:20 -0700 Nathan Chancellor <natechancellor@xxxxxxxxx> wrote: > 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 so there is not a real issue here. Use the > COMPARE_SECTIONS macro to silence this warning by casting the linker > defined symbols to unsigned long, which keeps the logic the same. > > Link: https://github.com/ClangBuiltLinux/linux/issues/765 > Signed-off-by: Nathan Chancellor <natechancellor@xxxxxxxxx> > --- > 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 c797a15a1fc7..e1f3b16e457b 100644 > --- a/kernel/trace/trace.c > +++ b/kernel/trace/trace.c > @@ -9332,7 +9332,7 @@ __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 (COMPARE_SECTIONS(__stop___trace_bprintk_fmt, !=, __start___trace_bprintk_fmt)) Sorry, but this is really ugly and unreadable. Please find some other solution to fix this. NAK-by: Steven Rostedt -- Steve > /* Must be called before global_trace.buffer is allocated */ > trace_printk_init_buffers(); >
