From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 73284 invoked by alias); 10 Dec 2019 06:23:18 -0000 Mailing-List: contact systemtap-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Post: List-Help: , Sender: systemtap-owner@sourceware.org Received: (qmail 73249 invoked by uid 48); 10 Dec 2019 06:23:13 -0000 From: "craig.ringer at 2ndquadrant dot com" To: systemtap@sourceware.org Subject: [Bug runtime/25267] New: kernel 5.3: error: this statement may fall through [-Werror=implicit-fallthrough=] Date: Tue, 10 Dec 2019 06:23:00 -0000 X-Bugzilla-Reason: AssignedTo X-Bugzilla-Type: new X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: systemtap X-Bugzilla-Component: runtime X-Bugzilla-Version: unspecified X-Bugzilla-Keywords: X-Bugzilla-Severity: normal X-Bugzilla-Who: craig.ringer at 2ndquadrant dot com X-Bugzilla-Status: UNCONFIRMED X-Bugzilla-Resolution: X-Bugzilla-Priority: P2 X-Bugzilla-Assigned-To: systemtap at sourceware dot org X-Bugzilla-Target-Milestone: --- X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: bug_id short_desc product version bug_status bug_severity priority component assigned_to reporter target_milestone Message-ID: 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: 2019-q4/txt/msg00060.txt.bz2 https://sourceware.org/bugzilla/show_bug.cgi?id=3D25267 Bug ID: 25267 Summary: kernel 5.3: error: this statement may fall through [-Werror=3Dimplicit-fallthrough=3D] Product: systemtap Version: unspecified Status: UNCONFIRMED Severity: normal Priority: P2 Component: runtime Assignee: systemtap at sourceware dot org Reporter: craig.ringer at 2ndquadrant dot com Target Milestone: --- When building on kernel 5.3.14 with stap 4.2/0.177 (git describe =3D release-4.2-6-g0c5c0f434) stap modules fail to build due to a runtime confi= gure bug detailed in #25265 . When this is worked around locally the build then fails due to -Werror complaints from gcc 9.2.1 : ~~~ In file included from /usr/local/share/systemtap/runtime/unwind.c:16, from /usr/local/share/systemtap/runtime/linux/runtime.h:25= 5, from /usr/local/share/systemtap/runtime/runtime.h:26, from /tmp/stapsiNon3/stap_767845_src.c:27: /usr/local/share/systemtap/runtime/unwind/unwind.h: In function =E2=80=98read_ptr_sect=E2=80=99: /usr/local/share/systemtap/runtime/unwind/unwind.h:146:20: error: this statement may fall through [-Werror=3Dimplicit-fallthrough=3D] 146 | if (!compat_task || (compat_task && (tableSize =3D=3D 4 || tableS= ize =3D=3D 0))) |=20=20=20=20=20=20 ~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ /usr/local/share/systemtap/runtime/unwind/unwind.h:157:2: note: here 157 | case DW_EH_PE_data8: | ^~~~ In file included from ./include/asm-generic/bug.h:5, from ./arch/x86/include/asm/bug.h:83, from ./include/linux/bug.h:5, from ./include/linux/mmdebug.h:5, from ./include/linux/gfp.h:5, from /usr/local/share/systemtap/runtime/linux/runtime_defines.h:20, from /usr/local/share/systemtap/runtime/runtime_defines.h:= 8, from /tmp/stapsiNon3/stap_767845_src.c:11: ./include/linux/compiler.h:328:5: error: this statement may fall through [-Werror=3Dimplicit-fallthrough=3D] 328 | do { \ | ^ ./include/linux/compiler.h:338:2: note: in expansion of macro =E2=80=98__compiletime_assert=E2=80=99 338 | __compiletime_assert(condition, msg, prefix, suffix) | ^~~~~~~~~~~~~~~~~~~~ ./include/linux/compiler.h:350:2: note: in expansion of macro =E2=80=98_compiletime_assert=E2=80=99 350 | _compiletime_assert(condition, msg, __compiletime_assert_, __LINE_= _) | ^~~~~~~~~~~~~~~~~~~ ./include/linux/build_bug.h:39:37: note: in expansion of macro =E2=80=98compiletime_assert=E2=80=99 39 | #define BUILD_BUG_ON_MSG(cond, msg) compiletime_assert(!(cond), msg) | ^~~~~~~~~~~~~~~~~~ ./include/linux/build_bug.h:50:2: note: in expansion of macro =E2=80=98BUILD_BUG_ON_MSG=E2=80=99 50 | BUILD_BUG_ON_MSG(condition, "BUILD_BUG_ON failed: " #condition) | ^~~~~~~~~~~~~~~~ /usr/local/share/systemtap/runtime/unwind/unwind.h:158:3: note: in expansio= n of macro =E2=80=98BUILD_BUG_ON=E2=80=99 158 | BUILD_BUG_ON(sizeof(u64) !=3D sizeof(value)); | ^~~~~~~~~~~~ In file included from /usr/local/share/systemtap/runtime/unwind.c:16, from /usr/local/share/systemtap/runtime/linux/runtime.h:25= 5, from /usr/local/share/systemtap/runtime/runtime.h:26, from /tmp/stapsiNon3/stap_767845_src.c:27: /usr/local/share/systemtap/runtime/unwind/unwind.h:163:2: note: here 163 | case DW_EH_PE_absptr: | ^~~~ In file included from /usr/local/share/systemtap/runtime/linux/runtime.h:25= 5, from /usr/local/share/systemtap/runtime/runtime.h:26, from /tmp/stapsiNon3/stap_767845_src.c:27: /usr/local/share/systemtap/runtime/unwind.c: In function =E2=80=98processCF= I=E2=80=99: /usr/local/share/systemtap/runtime/unwind.c:519:8: error: this statement may fall through [-Werror=3Dimplicit-fallthrough=3D] 519 | if (compat_task) { | ^ /usr/local/share/systemtap/runtime/unwind.c:531:4: note: here 531 | case DW_CFA_def_cfa_offset: | ^~~~ /usr/local/share/systemtap/runtime/unwind.c:543:8: error: this statement may fall through [-Werror=3Dimplicit-fallthrough=3D] 543 | if (compat_task) { | ^ /usr/local/share/systemtap/runtime/unwind.c:553:4: note: here 553 | case DW_CFA_def_cfa_offset_sf: | ^~~~ cc1: all warnings being treated as errors ~~~ Editing the generated Makefile to remove -Werror i.e. - EXTRA_CFLAGS +=3D -Wno-unused $(call cc-option,-Wno-tautological-compare) -Werror + EXTRA_CFLAGS +=3D -Wno-unused $(call cc-option,-Wno-tautological-compare) permits the trace module to compile. However, buildrun.cxx says ~~~ // A bit of obfuscation for Gentoo's sake. // We *need* -Werror for stapconf to work correctly. // https://bugs.gentoo.org/show_bug.cgi?id=3D522908 #define WERROR ("-W" "error") ~~~ ... so I presume some of the runtime configure tests are relying on things = like implicit function declaration warnings, and anyway it's not desirable to ju= st ignore warnings. It's unfortunate that staprun offers no way to disable -Werror or selective= ly suppress some -Werror sub-categories though, as it makes stap very fragile = in the face of compiler and kernel changes. --=20 You are receiving this mail because: You are the assignee for the bug.