From mboxrd@z Thu Jan 1 00:00:00 1970 From: Randy Dunlap Subject: Re: linux-next: Tree for Apr 3 (objtool) Date: Fri, 5 Apr 2019 13:53:27 -0700 Message-ID: <15ed85f4-bf2e-da91-71c1-46875d1c6e3f@infradead.org> References: <20190403192407.13a99513@canb.auug.org.au> <20190403205305.tqqwttjytunzgtub@treble> <6a2455b9-5c02-99dc-e41c-e6b7d1c3118d@infradead.org> <20190404171618.6u36y5zu3euvd4zp@treble> <9e4eb742-f306-7aea-a3d7-9abbb244bb55@infradead.org> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <9e4eb742-f306-7aea-a3d7-9abbb244bb55@infradead.org> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org To: Josh Poimboeuf Cc: Stephen Rothwell , Linux Next Mailing List , Linux Kernel Mailing List , Peter Zijlstra List-Id: linux-next.vger.kernel.org On 4/4/19 1:51 PM, Randy Dunlap wrote: > On 4/4/19 10:16 AM, Josh Poimboeuf wrote: >> On Wed, Apr 03, 2019 at 03:29:17PM -0700, Randy Dunlap wrote: >>> On 4/3/19 1:53 PM, Josh Poimboeuf wrote: >>>> On Wed, Apr 03, 2019 at 08:02:43AM -0700, Randy Dunlap wrote: >>>>> On 4/3/19 1:24 AM, Stephen Rothwell wrote: >>>>>> Hi all, >>>>>> >>>>>> Changes since 20190402: >>>>>> >>>>> >>>>> on x86_64: >>>>> >>>>> arch/x86/entry/entry_64.o: warning: objtool: .entry.text+0x909: unreachable instruction >>>> >>>> Your .o file looks odd. I can't recreate the issue when I build the >>>> same object. >>> >>> This (randconfig) build has tracing enabled? Could that have anything to do >>> with it? >> >> No, I can't see any reasonable explanation for it other than a buggy >> toolchain. >> >>> The randconfig file is attached. >> >> I still can't recreate with your randconfig. >> >>>> Did the issue only just now show up? Can you bisect it? What version >>>> of binutils are you using? >>> >>>> ld -v >>> GNU ld (GNU Binutils; openSUSE Leap 42.3) 2.31.1.20180828-19 >>> >>> >>> My build logs show it first occurred (in my randconfig builds) in >>> linux-next-20190204. >> >> It seems really odd. Can you do a bisect? >> > > Sure, I'll give it a try. > That didn't work very well. First I narrowed the problem down to between 4.16 (good) and 4.17-rc1 (bad), then I did the git bisects, and ended up pointing to a SCSI driver patch. I'm inclined to suspect that it's a padding problem, i.e. toolchain problem like you suggested. -- ~Randy