From owner-freebsd-arm@freebsd.org Thu Sep 1 14:46:29 2016 Return-Path: Delivered-To: freebsd-arm@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 16441BCB794 for ; Thu, 1 Sep 2016 14:46:29 +0000 (UTC) (envelope-from markmi@dsl-only.net) Received: from asp.reflexion.net (outbound-mail-210-26.reflexion.net [208.70.210.26]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id CF82FA7B for ; Thu, 1 Sep 2016 14:46:28 +0000 (UTC) (envelope-from markmi@dsl-only.net) Received: (qmail 24020 invoked from network); 1 Sep 2016 14:46:22 -0000 Received: from unknown (HELO mail-cs-01.app.dca.reflexion.local) (10.81.19.1) by 0 (rfx-qmail) with SMTP; 1 Sep 2016 14:46:22 -0000 Received: by mail-cs-01.app.dca.reflexion.local (Reflexion email security v8.00.0) with SMTP; Thu, 01 Sep 2016 10:46:25 -0400 (EDT) Received: (qmail 4289 invoked from network); 1 Sep 2016 14:46:25 -0000 Received: from unknown (HELO iron2.pdx.net) (69.64.224.71) by 0 (rfx-qmail) with (AES256-SHA encrypted) SMTP; 1 Sep 2016 14:46:25 -0000 Received: from [192.168.0.104] (ip70-189-131-151.lv.lv.cox.net [70.189.131.151]) by iron2.pdx.net (Postfix) with ESMTPSA id A611CEC8FBA; Thu, 1 Sep 2016 07:46:20 -0700 (PDT) From: Mark Millard Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: quoted-printable Subject: armv6 specific std::async crash from g++6 built a.out [stable/11 -r304943 context; /usr/ports -r421001 context] Message-Id: <25A60F75-B228-4C95-A890-8D6A8DA3F2CE@dsl-only.net> Date: Thu, 1 Sep 2016 07:46:20 -0700 To: freebsd-arm , FreeBSD Ports Mime-Version: 1.0 (Mac OS X Mail 9.3 \(3124\)) X-Mailer: Apple Mail (2.3124) X-BeenThere: freebsd-arm@freebsd.org X-Mailman-Version: 2.1.22 Precedence: list List-Id: "Porting FreeBSD to ARM processors." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 01 Sep 2016 14:46:29 -0000 [I've only compared armv6 and amd64 behavior for this. amd64 did not get = the problem.] The program is under 40 lines and is shown below: (It is a simplification of the context of the original discovery.) > # more g++6_build_crashes.cpp=20 > #include // vector > #include // future, async, launch::async > #include // thread::hardware_concurrency > =20 > decltype(std::thread::hardware_concurrency()) static = parallel_count{0u}; > =20 > static void take_time_measurements() {} > =20 > int main(int, const char* []) > { > parallel_count =3D std::thread::hardware_concurrency(); > // Do not presume more threads than this are possible. > =20 > if (1 < parallel_count) > { > --parallel_count; // leave room for main's thread. > =20 > std::vector> parallels{}; > parallels.reserve(parallel_count); > =20 > parallels.emplace_back > ( std::async( std::launch::async, take_time_measurements ) = ); > =20 > parallels.emplace_back > ( std::async( std::launch::async, take_time_measurements ) = ); > =20 > for (auto const& at : parallels) > { at.wait(); } > =20 > for (auto& at : parallels) > { at.get(); } > } > return 0; > } I do not know if the problem is a bad interaction between FreeBSD's = -pthread and g++6's library code vs. if this is strictly a g++6 library = problem somehow specific to armv6. g++6 based builds run fine in my amd64 context (FreeBSD stable/11 under = VirtualBox under Mac OS X). The clang++ 3.8.0 system compiler based build works fine on both amd64 = and armv6 (an rpi2). Builds via g++6 on the rpi2 produce an a.out that fails as shown below = (SIGSEGV): > # /usr/local/bin/gdb ./a.out > GNU gdb (GDB) 7.11.1 [GDB v7.11.1 for FreeBSD] > Copyright (C) 2016 Free Software Foundation, Inc. > License GPLv3+: GNU GPL version 3 or later = > This is free software: you are free to change and redistribute it. > There is NO WARRANTY, to the extent permitted by law. Type "show = copying" > and "show warranty" for details. > This GDB was configured as "armv6-portbld-freebsd11.0". > Type "show configuration" for configuration details. > For bug reporting instructions, please see: > . > Find the GDB manual and other documentation resources online at: > . > For help, type "help". > Type "apropos word" to search for commands related to "word"... > Reading symbols from ./a.out...done. > (gdb) run > Starting program: /root/c_tests/a.out=20 > [New LWP 100255 of process 12266] > =20 > Thread 2 received signal SIGSEGV, Segmentation fault. > [Switching to LWP 100255 of process 12266] > 0x00000000 in ?? () > (gdb) bt > #0 0x00000000 in ?? () > #1 0x200b2acc in _pthread_once (once_control=3D, = init_routine=3D) at = /usr/src/lib/libthr/thread/thr_once.c:95 > #2 0x0001312c in __gthread_once (__func=3D, = __once=3D0x20824024) at = /usr/local/lib/gcc6/include/c++/armv6-portbld-freebsd11.0/bits/gthr-defaul= t.h:699 > #3 std::call_once = ()>*, bool*), std::__future_b > ase::_State_baseV2*, = std::function ()>*, = bool*>(std::once_flag&, void (std::__future_base::_State_baseV2:: > *&&)(std::function ()>*, bool*), = std::__future_base::_State_baseV2*&&, = std::function __future_base::_Result_base, = std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&) = (__f=3D, __once=3D...) at = /usr/local/lib/gcc6/include/c++/mutex:619 > #4 = std::__future_base::_State_baseV2::_M_set_result(std::function ()>, bool) = (__ignore_failure=3Dfalse,=20 > __res=3D..., this=3D0x2082400c) at = /usr/local/lib/gcc6/include/c++/future:393 > #5 std::__future_base::_Async_state_impl, void>::_Async_state_impl(std::_Bind_simple&&)::{lambda()#1}::operator()() const (__closure=3D0x2082500c) > at /usr/local/lib/gcc6/include/c++/future:1664 > #6 = std::_Bind_simple, void>::_Async_state_impl(std::_Bind_simple&&)::{lambda()#1} ()>::_M_invoke<>(std::_Index_tupl > e<>) (this=3D0x2082500c) at = /usr/local/lib/gcc6/include/c++/functional:1400 > #7 = std::_Bind_simple, void>::_Async_state_impl(std::_Bind_simple&&)::{lambda()#1} ()>::operator()() ( > this=3D0x2082500c) at = /usr/local/lib/gcc6/include/c++/functional:1389 > #8 = std::thread::_State_impl, = void>::_Async_state_impl(std::_Bind_simple&&)::{lambda()#1} ()> >::_ > M_run() (this=3D0x20825008) at = /usr/local/lib/gcc6/include/c++/thread:196 > #9 0x201ac464 in std::execute_native_thread_routine (__p=3D0x20825008) = at = /usr/obj/portswork/usr/ports/lang/gcc6/work/gcc-6.2.0/libstdc++-v3/src/c++= 11/thread.cc:83 > #10 0x200a9fd4 in thread_start (curthread=3D) at = /usr/src/lib/libthr/thread/thr_create.c:289 > #11 0x200a9a90 in _pthread_create (thread=3D0xbfbfecbc, = attr=3D, start_routine=3D, arg=3D) at /usr/src/lib/libthr/thread/thr_create.c:185 > #12 0x201ac724 in __gthread_create (__args=3D, = __func=3D0x201ac450 , = __threadid=3D0xbfbfec84) > at = /usr/obj/portswork/usr/ports/lang/gcc6/work/.build/armv6-portbld-freebsd11= .0/libstdc++-v3/include/armv6-portbld-freebsd11.0/bits/gthr-default.h:662 > #13 std::thread::_M_start_thread (this=3Dthis@entry=3D0xbfbfecb4, = state=3Dstd::unique_ptr containing 0x20825018) > at = /usr/obj/portswork/usr/ports/lang/gcc6/work/gcc-6.2.0/libstdc++-v3/src/c++= 11/thread.cc:163 > #14 0x000138ec in = std::thread::thread, void>::_Async_state_impl(std::_Bind_simple&&)::{lambda()#1}>(std::__future_ba > se::_Async_state_impl, = void>::_Async_state_impl(std::_Bind_simple&&)::{lambda()#1}&&) (__f=3D, this=3D0xbfbfecb4) > at /usr/local/lib/gcc6/include/c++/thread:136 > #15 std::__future_base::_Async_state_impl, void>::_Async_state_impl(std::_Bind_simple&&) = (__fn=3D, this=3D0x2082404c) > at /usr/local/lib/gcc6/include/c++/future:1661 > #16 = __gnu_cxx::new_allocator, void> = >::construct, void>, std > ::_Bind_simple = >(std::__future_base::_Async_state_impl, = void>*, std::_Bind_simple&&) (this=3D, = __p=3D) > at /usr/local/lib/gcc6/include/c++/ext/new_allocator.h:120 > #17 = std::allocator_traits, void> > = >::construct )>, void>, std::_Bind_simple = >(std::allocator, void> >&, = std::__future_base::_Async_state_impl d (*())()>, void>*, std::_Bind_simple&&) (__a=3D..., = __p=3D) at = /usr/local/lib/gcc6/include/c++/bits/alloc_traits.h:455 > #18 = std::_Sp_counted_ptr_inplace, void>, = std::allocator, voi > d> >, = (__gnu_cxx::_Lock_policy)2>::_Sp_counted_ptr_inplace = >(std::allocator, void> >, std::_Bind_s > imple&&) (__a=3D..., this=3D0x20824040) at = /usr/local/lib/gcc6/include/c++/bits/shared_ptr_base.h:520 > #19 = std::__shared_count<(__gnu_cxx::_Lock_policy)2>::__shared_count, void>, = std::allocator td::_Bind_simple, void> >, std::_Bind_simple >(std::_Sp_make_shared_tag, = std::__future_base::_Async_state_impl, = void>*, std::allocator __future_base::_Async_state_impl, = void> > const&, std::_Bind_simple&&) (__a=3D..., = this=3D) > at /usr/local/lib/gcc6/include/c++/bits/shared_ptr_base.h:615 > #20 = std::__shared_ptr, void>, = (__gnu_cxx::_Lock_policy)2>::__shared_ptr _Bind_simple, void> >, std::_Bind_simple = >(std::_Sp_make_shared_tag, = std::allocator, void> > const&, s > td::_Bind_simple&&) (__a=3D..., __tag=3D..., = this=3D) at = /usr/local/lib/gcc6/include/c++/bits/shared_ptr_base.h:1100 > #21 = std::shared_ptr, void> = >::shared_ptr, voi > d> >, std::_Bind_simple >(std::_Sp_make_shared_tag, = std::allocator, void> > const&, std::_Bind_simple& > &) (__a=3D..., __tag=3D..., this=3D) at = /usr/local/lib/gcc6/include/c++/bits/shared_ptr.h:319 > #22 = std::allocate_shared, void>, = std::allocator, void> >, st > d::_Bind_simple = >(std::allocator, void> > const&, std::_Bind_simple&&) = (__a=3D...) > at /usr/local/lib/gcc6/include/c++/bits/shared_ptr.h:620 > #23 = std::make_shared, void>, std::_Bind_simple = >(std::_Bind_simple&&) () > at /usr/local/lib/gcc6/include/c++/bits/shared_ptr.h:636 > #24 std::__future_base::_S_make_async_state >(std::_Bind_simple&&) (__fn=3D) = at /usr/local/lib/gcc6/include/c++/future:1702 > #25 std::async = (__policy=3D__policy@entry=3Dstd::launch::async, __fn=3D@0x120d8: {void = (void)} 0x120d8 ) at = /usr/local/lib/gcc6/include/c++/future:1716 > #26 0x00011788 in main () at g++6_build_crashes.cpp:25 > (gdb) Context: > # uname -apKU > FreeBSD rpi2 11.0-PRERELEASE FreeBSD 11.0-PRERELEASE #5 r304943M: Sun = Aug 28 03:17:54 PDT 2016 = markmi@FreeBSDx64:/usr/obj/clang/arm.armv6/usr/src/sys/RPI2-NODBG arm = armv6 1100502 1100502 > # svnlite info /usr/src | grep "Re[vl][ai:]" > Relative URL: ^/stable/11 > Revision: 304943 > Last Changed Rev: 304943 > # svnlite info /usr/ports | grep "Re[vl][ai:]" > Relative URL: ^/head > Revision: 421001 > Last Changed Rev: 421001 > # more /etc/make.conf=20 > DEFAULT_VERSIONS+=3Dperl5=3D5.22 > WRKDIRPREFIX=3D/usr/obj/portswork > WITH_DEBUG=3D > WITH_DEBUG_FILES=3D > MALLOC_PRODUCTION=3D The compiler -v output is shown in the below: (Removing the -mcpu=3Dcortex-a7 still gets the problem. Using -O0 = instead of -O2 also still gets the problem.) > Script started on Thu Sep 1 06:52:45 2016 > Command: g++6 -g -v -std=3Dc++14 -Wpedantic -Wall -O2 -pthread = -Wl,-rpath=3D/usr/local/lib/gcc6 -mcpu=3Dcortex-a7 = g++6_build_crashes.cpp > Using built-in specs. > COLLECT_GCC=3Dg++6 > = COLLECT_LTO_WRAPPER=3D/usr/local/libexec/gcc6/gcc/armv6-portbld-freebsd11.= 0/6.2.0/lto-wrapper > Target: armv6-portbld-freebsd11.0 > Configured with: = /usr/obj/portswork/usr/ports/lang/gcc6/work/gcc-6.2.0/configure = --disable-multilib --disable-bootstrap --disable-nls = --enable-gnu-indirect-function --libdir=3D/usr/local/lib/gcc6 --libe > xecdir=3D/usr/local/libexec/gcc6 --program-suffix=3D6 = --with-as=3D/usr/local/bin/as --with-gmp=3D/usr/local = --with-gxx-include-dir=3D/usr/local/lib/gcc6/include/c++/ = --with-ld=3D/usr/local/bin/ld --with-pkgversio > n=3D'FreeBSD Ports Collection' --with-system-zlib --disable-libgcj = --enable-languages=3Dc,c++,objc,fortran --prefix=3D/usr/local = --localstatedir=3D/var --mandir=3D/usr/local/man = --infodir=3D/usr/local/info/gcc6 - > -build=3Darmv6-portbld-freebsd11.0 > Thread model: posix > gcc version 6.2.0 (FreeBSD Ports Collection)=20 > COLLECT_GCC_OPTIONS=3D'-g' '-v' '-std=3Dc++14' '-Wpedantic' '-Wall' = '-O2' '-pthread' '-mcpu=3Dcortex-a7' '-shared-libgcc' = '-mtls-dialect=3Dgnu' > /usr/local/libexec/gcc6/gcc/armv6-portbld-freebsd11.0/6.2.0/cc1plus = -quiet -v g++6_build_crashes.cpp -quiet -dumpbase g++6_build_crashes.cpp = -mcpu=3Dcortex-a7 -mtls-dialect=3Dgnu -auxbase g++6_build_cras > hes -g -O2 -Wpedantic -Wall -std=3Dc++14 -version -o /tmp//cc0nzkwI.s > GNU C++14 (FreeBSD Ports Collection) version 6.2.0 = (armv6-portbld-freebsd11.0) > compiled by GNU C version 4.2.1 Compatible FreeBSD Clang 3.8.0 = (tags/RELEASE_380/final 262564), GMP version 5.1.3, MPFR version = 3.1.4-p1, MPC version 1.0.3, isl version none > GGC heuristics: --param ggc-min-expand=3D93 --param = ggc-min-heapsize=3D119509 > ignoring nonexistent directory = "/usr/local/lib/gcc6/gcc/armv6-portbld-freebsd11.0/6.2.0/../../../../../ar= mv6-portbld-freebsd11.0/include" > #include "..." search starts here: > #include <...> search starts here: > /usr/local/lib/gcc6/include/c++/ > /usr/local/lib/gcc6/include/c++//armv6-portbld-freebsd11.0 > /usr/local/lib/gcc6/include/c++//backward > /usr/local/lib/gcc6/gcc/armv6-portbld-freebsd11.0/6.2.0/include > /usr/local/include > /usr/local/lib/gcc6/gcc/armv6-portbld-freebsd11.0/6.2.0/include-fixed > /usr/include > End of search list. > GNU C++14 (FreeBSD Ports Collection) version 6.2.0 = (armv6-portbld-freebsd11.0) > compiled by GNU C version 4.2.1 Compatible FreeBSD Clang 3.8.0 = (tags/RELEASE_380/final 262564), GMP version 5.1.3, MPFR version = 3.1.4-p1, MPC version 1.0.3, isl version none > GGC heuristics: --param ggc-min-expand=3D93 --param = ggc-min-heapsize=3D119509 > Compiler executable checksum: 0997b9bc5b083d9cfbb96481fb14adbd > COLLECT_GCC_OPTIONS=3D'-g' '-v' '-std=3Dc++14' '-Wpedantic' '-Wall' = '-O2' '-pthread' '-mcpu=3Dcortex-a7' '-shared-libgcc' = '-mtls-dialect=3Dgnu' > /usr/local/bin/as -v -mcpu=3Dcortex-a7 -mfpu=3Dvfp -meabi=3D5 -o = /tmp//ccx4UQrB.o /tmp//cc0nzkwI.s > GNU assembler version 2.27 (armv6-portbld-freebsd11.0) using BFD = version (GNU Binutils) 2.27 > = COMPILER_PATH=3D/usr/local/libexec/gcc6/gcc/armv6-portbld-freebsd11.0/6.2.= 0/:/usr/local/libexec/gcc6/gcc/armv6-portbld-freebsd11.0/6.2.0/:/usr/local= /libexec/gcc6/gcc/armv6-portbld-freebsd11.0/:/usr/loca > = l/lib/gcc6/gcc/armv6-portbld-freebsd11.0/6.2.0/:/usr/local/lib/gcc6/gcc/ar= mv6-portbld-freebsd11.0/:/usr/local/lib/gcc6/gcc/armv6-portbld-freebsd11.0= /6.2.0/../../../../../armv6-portbld-freebsd11.0/bin/ > = LIBRARY_PATH=3D/usr/local/lib/gcc6/gcc/armv6-portbld-freebsd11.0/6.2.0/:/u= sr/local/lib/gcc6/gcc/armv6-portbld-freebsd11.0/6.2.0/../../../../../armv6= -portbld-freebsd11.0/lib/:/usr/local/lib/gcc6/gcc/armv > 6-portbld-freebsd11.0/6.2.0/../../../:/lib/:/usr/lib/ > COLLECT_GCC_OPTIONS=3D'-g' '-v' '-std=3Dc++14' '-Wpedantic' '-Wall' = '-O2' '-pthread' '-mcpu=3Dcortex-a7' '-shared-libgcc' = '-mtls-dialect=3Dgnu' > /usr/local/libexec/gcc6/gcc/armv6-portbld-freebsd11.0/6.2.0/collect2 = -plugin = /usr/local/libexec/gcc6/gcc/armv6-portbld-freebsd11.0/6.2.0/liblto_plugin.= so -plugin-opt=3D/usr/local/libexec/gcc6/gcc/armv6 > -portbld-freebsd11.0/6.2.0/lto-wrapper = -plugin-opt=3D-fresolution=3D/tmp//ccD1bSsW.res = -plugin-opt=3D-pass-through=3D-lgcc_s -plugin-opt=3D-pass-through=3D-lgcc = -plugin-opt=3D-pass-through=3D-lpthread -plugin-opt=3D-pa > ss-through=3D-lc -plugin-opt=3D-pass-through=3D-lgcc_s = -plugin-opt=3D-pass-through=3D-lgcc --eh-frame-hdr -V -dynamic-linker = /libexec/ld-elf.so.1 --hash-style=3Dboth --enable-new-dtags -X = /usr/lib/crt1.o /usr/lib > /crti.o = /usr/local/lib/gcc6/gcc/armv6-portbld-freebsd11.0/6.2.0/crtbegin.o = -L/usr/local/lib/gcc6/gcc/armv6-portbld-freebsd11.0/6.2.0 = -L/usr/local/lib/gcc6/gcc/armv6-portbld-freebsd11.0/6.2.0/../../../ > ../../armv6-portbld-freebsd11.0/lib = -L/usr/local/lib/gcc6/gcc/armv6-portbld-freebsd11.0/6.2.0/../../.. = -rpath=3D/usr/local/lib/gcc6 /tmp//ccx4UQrB.o -lstdc++ -lm -lgcc_s -lgcc = -lpthread -lc -lgcc_s -lgc > c /usr/local/lib/gcc6/gcc/armv6-portbld-freebsd11.0/6.2.0/crtend.o = /usr/lib/crtn.o > GNU ld (GNU Binutils) 2.27 > Supported emulations: . . . I end up having to kill -9 gdb as kill and quit each hang. Just running via ./a.out (no gdb) gets the SIGSEGV but does not hang. =3D=3D=3D Mark Millard markmi at dsl-only.net