From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 28907 invoked by alias); 17 Nov 2017 15:53:37 -0000 Mailing-List: contact elfutils-devel-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Post: List-Help: List-Subscribe: Sender: elfutils-devel-owner@sourceware.org Received: (qmail 28727 invoked by uid 48); 17 Nov 2017 15:53:32 -0000 From: "mark at klomp dot org" To: elfutils-devel@sourceware.org Subject: [Bug libdw/22452] Failed to obtain CFI data for a OP_call_frame_CFA when looking for func entrypoc in an s390 kernel module Date: Fri, 17 Nov 2017 15:53:00 -0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: elfutils X-Bugzilla-Component: libdw X-Bugzilla-Version: unspecified X-Bugzilla-Keywords: X-Bugzilla-Severity: normal X-Bugzilla-Who: mark at klomp dot org X-Bugzilla-Status: UNCONFIRMED X-Bugzilla-Resolution: X-Bugzilla-Priority: P2 X-Bugzilla-Assigned-To: unassigned at sourceware dot org X-Bugzilla-Target-Milestone: --- X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: Message-ID: In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: http://sourceware.org/bugzilla/ Auto-Submitted: auto-generated MIME-Version: 1.0 X-SW-Source: 2017-q4/txt/msg00054.txt.bz2 https://sourceware.org/bugzilla/show_bug.cgi?id=3D22452 --- Comment #4 from Mark Wielaard --- (In reply to H. Brueckner from comment #2) > (In reply to Mark Wielaard from comment #1) > > The .eh_frame is a loaded section, which means it won't go into the .de= bug > > file. So you would need to load the CFI from the main ELF .ko. >=20 > Initially, I have tried on my own kernel build (including debug_info) and > ran the test program against the .ko file. (Because I am not permitted to > share binary code and, please, do not ask why, it is difficult to provide > you an alternative. If you have access to a s390 or use a cross-compiler= it > would be fine but that typically requires some effort on your side. Don't worry, we have the split .ko/.debug files, it should in theory also w= ork (or show the same bug) with that. > In any case, if you require some output in text form, please let me know. >=20 > > One tricky issue here is the fact that kernel modules are ET_REL files > > that still need relocations applied (you can see there is also a > > .rela.eh_frame section). libdwfl can do simple relocations, but might n= ot > > know about all relocation types used in an .eh_frame section (I haven't > > checked yet). >=20 > Ok. So, if you could provide the output of eu-readelf --relocs paes_s390.ko (on your combined paes_s390.ko containing both code and debug) that would be helpful. If there are relocations in the .rela.eh_frame section that aren't "simple"= as defined in s390_reloc_simple_type (backends/backends/s390_symbol.c) that mi= ght be a hint. Also if you could trick you kernel build to generate CFI in .debug_frame instead of .eh_frame like other arches seem to do, that would make a good testcase. --=20 You are receiving this mail because: You are on the CC list for the bug.