From mboxrd@z Thu Jan 1 00:00:00 1970 From: Masami Hiramatsu Subject: Re: linux-next: build warnings from the build of Linus' tree Date: Tue, 28 Aug 2018 09:43:41 +0900 Message-ID: <20180828094341.d20d8fbcb9dca310d44df951@kernel.org> References: <20180824133206.4218c2e5@canb.auug.org.au> <20180824172053.20fa197294f51496dcec5605@kernel.org> <20180824204756.e787765461975cd1e27502dc@kernel.org> <20180824224211.2934d7c0@canb.auug.org.au> <20180826171058.e07f99e6e03f7497e5a46ed3@kernel.org> <20180828072333.36af4d5d@canb.auug.org.au> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20180828072333.36af4d5d@canb.auug.org.au> Sender: linux-kernel-owner@vger.kernel.org To: Stephen Rothwell , Peter Oberparleiter Cc: "Steven Rostedt (VMware)" , Linux-Next Mailing List , Linux Kernel Mailing List , arnd@arndb.de List-Id: linux-next.vger.kernel.org Hi Stephen, On Tue, 28 Aug 2018 07:23:33 +1000 Stephen Rothwell wrote: > Hi Masami, > > On Sun, 26 Aug 2018 17:10:58 +0900 Masami Hiramatsu wrote: > > > > Hmm, unfortunately, I couldn't reproduce the ".data..LPBX1" error with > > my gcc-8.1.0 + ld-2.30 distributed at https://cdn.kernel.org/pub/tools/crosstool/. > > Could you also try to enable CONFIG_GCOV_PROFILE_ALL=y and build the kernel? > > If it causes similar error, it should be caused by gcov support. > > Using the allyesconfig as a base and disabling CONFIG_COMPILE_TESTING > allowed me to enable COMFIG_GCOV_PROFILE_ALL, but that just generated a > lot more messages. Some about data..Lusan sections (I think). OK, so it sounds like GCOV kernel itself is broken with your toolchain (native gcc-8.2.0 on ppc64?) as same as arm32. I added Peter in loop, he is the maintainer of GCOV kernel. Hi Peter, I recently added a gcov profiling for ftrace, following Documentation/dev-tools/gcov.rst. 6b7dca401cb1 ("tracing: Allow gcov profiling on only ftrace subsystem") and it caused may orphan section warnings/errors on arm and powerpc64. We also found same error happens when CONFIG_GCOV_PROFILE_ALL=y. So I guess GCOV kernel subsystem broken in some environment. (cross build) gcc-7.3.0 + ld-2.30 => arm:NG, arm64:OK, powerpc64:OK gcc-8.1.0 + ld-2.30 => arm:NG, arm64:OK, powerpc64:OK (native build?) gcc-8.2.0 + ld 2.31.1 => powerpc64:NG gcc-7.2.1 + ld 2.27 => x86-64: OK ppc64 NG report: https://lkml.org/lkml/2018/8/24/72 arm NG report: https://lkml.org/lkml/2018/8/24/345 Would you know how we can fix this issue? Thank you, -- Masami Hiramatsu