From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 48) id 5DB673857734; Fri, 4 Aug 2023 13:03:04 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 5DB673857734 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sourceware.org; s=default; t=1691154184; bh=oe+XQPFTtxchgGR3RV2++KC1oGF24SpykKITiF7TitI=; h=From:To:Subject:Date:In-Reply-To:References:From; b=dh786hbbs7kMTxadiJFWbRxWkoOdPSj95YtEajkzQWDP3/fZXPfxd3WV29HUXBm2h gWavugdA6jkr6ZyI+7+EV5CDmXCj5LqlbhUcHihVbC1wK5eZ6qJweWyzNuwtlSwq5A NdyuVSxrzqE+CigEYiHqYyUAhr+aUD7DNbzC+zKc= From: "cvs-commit at gcc dot gnu.org" To: gdb-prs@sourceware.org Subject: [Bug symtab/30392] [gdb/symtab] thread sanitizer data race in gdb.base/index-cache.exp Date: Fri, 04 Aug 2023 13:03:02 +0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gdb X-Bugzilla-Component: symtab X-Bugzilla-Version: HEAD X-Bugzilla-Keywords: X-Bugzilla-Severity: normal X-Bugzilla-Who: cvs-commit at gcc dot gnu.org X-Bugzilla-Status: NEW 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 List-Id: https://sourceware.org/bugzilla/show_bug.cgi?id=3D30392 --- Comment #8 from cvs-commit at gcc dot gnu.org --- The master branch has been updated by Tom de Vries : https://sourceware.org/git/gitweb.cgi?p=3Dbinutils-gdb.git;h=3D8adc5522280c= 06c1c750185af0dc5a8461d9a13f commit 8adc5522280c06c1c750185af0dc5a8461d9a13f Author: Tom de Vries Date: Fri Aug 4 15:02:43 2023 +0200 [gdb/symtab] Fix data race on index_cache::m_enabled With gdb build with -fsanitize=3Dthread and test-case gdb.base/index-cache.exp I run into: ... (gdb) file build/gdb/testsuite/outputs/gdb.base/index-cache/index-cache Reading symbols from build/gdb/testsuite/outputs/gdb.base/index-cache/index-cache... (gdb) show index-cache enabled The index cache is off. (gdb) PASS: gdb.base/index-cache.exp: test_basic_stuff: index-cache is disabled by default set index-cache enabled on =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D WARNING: ThreadSanitizer: data race (pid=3D32248) Write of size 1 at 0x00000321f540 by main thread: #0 index_cache::enable() gdb/dwarf2/index-cache.c:76 (gdb+0x82cfdd) #1 set_index_cache_enabled_command gdb/dwarf2/index-cache.c:270 (gdb+0x82d9af) #2 bool setting::set(bool const&) gdb/command.h:353 (gdb+0x6fe5f2) #3 do_set_command(char const*, int, cmd_list_element*) gdb/cli/cli-setshow.c:414 (gdb+0x6fcd21) #4 execute_command(char const*, int) gdb/top.c:567 (gdb+0xff2e64) #5 command_handler(char const*) gdb/event-top.c:552 (gdb+0x94acc0) #6 command_line_handler(std::unique_ptr >&&) gdb/event-top.c:788 (gdb+0x94b37d) #7 tui_command_line_handler gdb/tui/tui-interp.c:104 (gdb+0x103467e) #8 gdb_rl_callback_handler gdb/event-top.c:259 (gdb+0x94a265) #9 rl_callback_read_char readline/readline/callback.c:290 (gdb+0x11bdd3f) #10 gdb_rl_callback_read_char_wrapper_noexcept gdb/event-top.c:195 (gdb+0x94a064) #11 gdb_rl_callback_read_char_wrapper gdb/event-top.c:234 (gdb+0x94a125) #12 stdin_event_handler gdb/ui.c:155 (gdb+0x1074922) #13 handle_file_event gdbsupport/event-loop.cc:573 (gdb+0x1d94de4) #14 gdb_wait_for_event gdbsupport/event-loop.cc:694 (gdb+0x1d9551c) #15 gdb_do_one_event(int) gdbsupport/event-loop.cc:264 (gdb+0x1d939= 08) #16 start_event_loop gdb/main.c:412 (gdb+0xb5a256) #17 captured_command_loop gdb/main.c:476 (gdb+0xb5a445) #18 captured_main gdb/main.c:1320 (gdb+0xb5c5c5) #19 gdb_main(captured_main_args*) gdb/main.c:1339 (gdb+0xb5c674) #20 main gdb/gdb.c:32 (gdb+0x416776) Previous read of size 1 at 0x00000321f540 by thread T12: #0 index_cache::enabled() const gdb/dwarf2/index-cache.h:48 (gdb+0x82e1a6) #1 index_cache::store(dwarf2_per_bfd*) gdb/dwarf2/index-cache.c:94 (gdb+0x82d0bc) #2 cooked_index::maybe_write_index(dwarf2_per_bfd*) gdb/dwarf2/cooked-index.c:638 (gdb+0x7f1b97) #3 operator() gdb/dwarf2/cooked-index.c:468 (gdb+0x7f0f24) #4 _M_invoke /usr/include/c++/7/bits/std_function.h:316 (gdb+0x7f28= 5b) #5 std::function::operator()() const /usr/include/c++/7/bits/std_function.h:706 (gdb+0x700952) #6 void std::__invoke_impl&>(std::__invoke_other, std::function&) /usr/include/c++/7/bits/invoke.h:60 (gdb+0x7381a0) #7 std::__invoke_result&>::type std::__invoke&>(std::function&) /usr/include/c++/7/bits/invoke.h:95 (gdb+0x737e91) #8 std::__future_base::_Task_state, std::allocator, void ()>::_M_run()::{lambda()#1}::operator()() const /usr/include/c++/7/future:1421 (gdb+0x737b59) #9 std::__future_base::_Task_setter, std::__future_base::_Result_base::_Deleter>, std::__future_base::_Task_state, std::allocator, void ()>::_M_run()::{lambda()#1}, void>::operator()() const /usr/include/c++/7/future:1362 (gdb+0x738660) #10 std::_Function_handler (), std::__future_base::_Task_setter, std::__future_base::_Result_base::_Deleter>, std::__future_base::_Task_state, std::allocator, void ()>::_M_run()::{lambda()#1}, void> >::_M_invoke(std::_Any_data const&) /usr/include/c++/7/bits/std_function.h:302 (gdb+0x73825c) #11 std::function ()>::operator()() const /usr/include/c++/7/bits/std_function.h:706 (gdb+0x733623) #12 std::__future_base::_State_baseV2::_M_do_set(std::function ()>*, bool*) /usr/include/c++/7/future:561 (gdb+0x732bdf) #13 void std::__invoke_impl ()>*, bool*), std::__future_base::_State_baseV2*, std::function ()>*, bool*>(std::__invoke_memfun_deref, void (std::__future_base::_State_baseV2::*&&)(std::function ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function ()>*&&, bool*&&) /usr/include/c++/7/bits/invoke.h:73 (gdb+0x734c4f) #14 std::__invoke_result ()>*, bool*), std::__future_base::_State_baseV2*, std::function ()>*, bool*>::type std::__invoke ()>*, bool*), std::__future_base::_State_baseV2*, std::function ()>*, bool*>(void (std::__future_base::_State_baseV2::*&&)(std::function ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function ()>*&&, bool*&&) /usr/include/c++/7/bits/invoke.h:95 (gdb+0x733bc5) #15 std::call_once ()>*, bool*), std::__future_base::_State_baseV2*, std::function ()>*, bool*>(std::once_flag&, v= oid (std::__future_base::_State_baseV2::*&&)(std::function ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function ()>*&&, bool*&&)::{lambda()#1}::operator()() const /usr/include/c++/7/mutex:672 (gdb+0x73300d) #16 std::call_once ()>*, bool*), std::__future_base::_State_baseV2*, std::function ()>*, bool*>(std::once_flag&, v= oid (std::__future_base::_State_baseV2::*&&)(std::function ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function ()>*&&, bool*&&)::{lambda()#2}::operator()() const /usr/include/c++/7/mutex:677 (gdb+0x7330b2) #17 std::call_once ()>*, bool*), std::__future_base::_State_baseV2*, std::function ()>*, bool*>(std::once_flag&, v= oid (std::__future_base::_State_baseV2::*&&)(std::function ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function ()>*&&, bool*&&)::{lambda()#2}::_FUN() /usr/include/c++/7/mutex:677 (gdb+0x7330f2) #18 pthread_once (libtsan.so.0+0x4457c) #19 __gthread_once /usr/include/c++/7/x86_64-suse-linux/bits/gthr-default.h:699 (gdb+0x72f5dd) #20 void std::call_once ()>*, bool*), std::__future_base::_State_baseV2*, std::function ()>*, bool*>(std::once_flag&, v= oid (std::__future_base::_State_baseV2::*&&)(std::function ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function ()>*&&, bool*&&) /usr/include/c++/7/mutex:684 (gdb+0x733224) #21 std::__future_base::_State_baseV2::_M_set_result(std::function ()>, bool) /usr/include/c++/7/future:401 (gdb+0x732852) #22 std::__future_base::_Task_state, std::allocator, void ()>::_M_run() /usr/include/c++/7/future:1423 (gdb+0x737bef) #23 std::packaged_task::operator()() /usr/include/c++/7/future:1556 (gdb+0x1dac492) #24 gdb::thread_pool::thread_function() gdbsupport/thread-pool.cc:2= 42 (gdb+0x1dabdb4) #25 void std::__invoke_impl(std::__invoke_memfun_deref, void (gdb::thread_pool::*&&)= (), gdb::thread_pool*&&) /usr/include/c++/7/bits/invoke.h:73 (gdb+0x1dace63) #26 std::__invoke_result::type std::__invoke(void (gdb::thread_pool::*&&)(), gdb::thread_pool*&&) /usr/include/c++/7/bits/invoke.h:95 (gdb+0x1dac294) #27 decltype (__invoke((_S_declval<0ul>)(), (_S_declval<1ul>)())) std::thread::_Invoker >::_M_invoke<0ul, 1ul>(std::_Index_tuple<0ul, 1ul>) /usr/include/c++/7/thread:234 (gdb+0x1daf5c6) #28 std::thread::_Invoker >::operator()() /usr/include/c++/7/thread:243 (gdb+0x1daf551) #29 std::thread::_State_impl > >::_M_run() /usr/include/c++/7/thread:186 (gdb+0x1daf506) #30 (libstdc++.so.6+0xdcac2) Location is global 'global_index_cache' of size 48 at 0x00000321f520 (gdb+0x00000321f540) ... SUMMARY: ThreadSanitizer: data race gdb/dwarf2/index-cache.c:76 in index_cache::enable() ... The race happens when issuing a "file $exec" command followed by a "set index-cache enabled on" command. The race is between: - a worker thread reading index_cache::m_enabled to determine whether an index-cache entry for $exec needs to be written (due to command "file $exec"), and - the main thread setting index_cache::m_enabled (due to command "set index-cache enabled on"). Fix this by capturing the value of index_cache::m_enabled in the main thread, and using the captured value in the worker thread. Tested on x86_64-linux. PR symtab/30392 Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=3D30392 --=20 You are receiving this mail because: You are on the CC list for the bug.=