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[142.68.57.212]) by smtp.gmail.com with ESMTPSA id p8sm490083qtn.71.2020.02.19.11.54.25 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Wed, 19 Feb 2020 11:54:25 -0800 (PST) Received: from jgg by mlx.ziepe.ca with local (Exim 4.90_1) (envelope-from ) id 1j4VQO-0006DL-Tx; Wed, 19 Feb 2020 15:54:24 -0400 Date: Wed, 19 Feb 2020 15:54:24 -0400 From: Jason Gunthorpe To: Nick Desaulniers Cc: Nathan Chancellor , Steven Rostedt , Masahiro Yamada , Michal Marek , Arnd Bergmann , Ingo Molnar , Jason Baron , Catalin Marinas , Andrew Morton , LKML , Linux Kbuild mailing list , linux-arch , Linux Memory Management List , clang-built-linux Subject: Re: [PATCH 3/6] tracing: Wrap section comparison in tracer_alloc_buffers with COMPARE_SECTIONS Message-ID: <20200219195424.GW31668@ziepe.ca> References: <20200219045423.54190-1-natechancellor@gmail.com> <20200219045423.54190-4-natechancellor@gmail.com> <20200219093445.386f1c09@gandalf.local.home> <20200219181619.GV31668@ziepe.ca> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.9.4 (2018-02-28) X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Wed, Feb 19, 2020 at 11:11:19AM -0800, Nick Desaulniers wrote: > > Godbolt says clang is happy if it is written as: > > > > if (&__stop___trace_bprintk_fmt[0] != &__start___trace_bprintk_fmt[0]) > > > > Which is probably the best compromise. The type here is const char > > *[], so it would be a shame to see it go. > > If the "address" is never dereferenced, but only used for arithmetic > (in a way that the the pointed to type is irrelevant), does the > pointed to type matter? The type is used here: if (*pos < start_index) return __start___trace_bprintk_fmt + *pos; The return expression should be a const char ** Presumably the caller of find_next derferences it. Jason