binutils-gdb/gdb/target/waitstatus.c

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/* Target waitstatus implementations.
Copyright (C) 1990-2020 Free Software Foundation, Inc.
This file is part of GDB.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>. */
Rename common to gdbsupport This is the next patch in the ongoing series to move gdbsever to the top level. This patch just renames the "common" directory. The idea is to do this move in two parts: first rename the directory (this patch), then move the directory to the top. This approach makes the patches a bit more tractable. I chose the name "gdbsupport" for the directory. However, as this patch was largely written by sed, we could pick a new name without too much difficulty. Tested by the buildbot. gdb/ChangeLog 2019-07-09 Tom Tromey <tom@tromey.com> * contrib/ari/gdb_ari.sh: Change common to gdbsupport. * configure: Rebuild. * configure.ac: Change common to gdbsupport. * gdbsupport: Rename from common. * acinclude.m4: Change common to gdbsupport. * Makefile.in (CONFIG_SRC_SUBDIR, COMMON_SFILES) (HFILES_NO_SRCDIR, stamp-version, ALLDEPFILES): Change common to gdbsupport. * aarch64-tdep.c, ada-lang.c, ada-lang.h, agent.c, alloc.c, amd64-darwin-tdep.c, amd64-dicos-tdep.c, amd64-fbsd-nat.c, amd64-fbsd-tdep.c, amd64-linux-nat.c, amd64-linux-tdep.c, amd64-nbsd-tdep.c, amd64-obsd-tdep.c, amd64-sol2-tdep.c, amd64-tdep.c, amd64-windows-tdep.c, arch-utils.c, arch/aarch64-insn.c, arch/aarch64.c, arch/aarch64.h, arch/amd64.c, arch/amd64.h, arch/arm-get-next-pcs.c, arch/arm-linux.c, arch/arm.c, arch/i386.c, arch/i386.h, arch/ppc-linux-common.c, arch/riscv.c, arch/riscv.h, arch/tic6x.c, arm-tdep.c, auto-load.c, auxv.c, ax-gdb.c, ax-general.c, ax.h, breakpoint.c, breakpoint.h, btrace.c, btrace.h, build-id.c, build-id.h, c-lang.h, charset.c, charset.h, cli/cli-cmds.c, cli/cli-cmds.h, cli/cli-decode.c, cli/cli-dump.c, cli/cli-option.h, cli/cli-script.c, coff-pe-read.c, command.h, compile/compile-c-support.c, compile/compile-c.h, compile/compile-cplus-symbols.c, compile/compile-cplus-types.c, compile/compile-cplus.h, compile/compile-loc2c.c, compile/compile.c, completer.c, completer.h, contrib/ari/gdb_ari.sh, corefile.c, corelow.c, cp-support.c, cp-support.h, cp-valprint.c, csky-tdep.c, ctf.c, darwin-nat.c, debug.c, defs.h, disasm-selftests.c, disasm.c, disasm.h, dtrace-probe.c, dwarf-index-cache.c, dwarf-index-cache.h, dwarf-index-write.c, dwarf2-frame.c, dwarf2expr.c, dwarf2loc.c, dwarf2read.c, event-loop.c, event-top.c, exceptions.c, exec.c, extension.h, fbsd-nat.c, features/aarch64-core.c, features/aarch64-fpu.c, features/aarch64-pauth.c, features/aarch64-sve.c, features/i386/32bit-avx.c, features/i386/32bit-avx512.c, features/i386/32bit-core.c, features/i386/32bit-linux.c, features/i386/32bit-mpx.c, features/i386/32bit-pkeys.c, features/i386/32bit-segments.c, features/i386/32bit-sse.c, features/i386/64bit-avx.c, features/i386/64bit-avx512.c, features/i386/64bit-core.c, features/i386/64bit-linux.c, features/i386/64bit-mpx.c, features/i386/64bit-pkeys.c, features/i386/64bit-segments.c, features/i386/64bit-sse.c, features/i386/x32-core.c, features/riscv/32bit-cpu.c, features/riscv/32bit-csr.c, features/riscv/32bit-fpu.c, features/riscv/64bit-cpu.c, features/riscv/64bit-csr.c, features/riscv/64bit-fpu.c, features/tic6x-c6xp.c, features/tic6x-core.c, features/tic6x-gp.c, filename-seen-cache.h, findcmd.c, findvar.c, fork-child.c, gcore.c, gdb_bfd.c, gdb_bfd.h, gdb_proc_service.h, gdb_regex.c, gdb_select.h, gdb_usleep.c, gdbarch-selftests.c, gdbthread.h, gdbtypes.h, gnu-nat.c, go32-nat.c, guile/guile.c, guile/scm-ports.c, guile/scm-safe-call.c, guile/scm-type.c, i386-fbsd-nat.c, i386-fbsd-tdep.c, i386-go32-tdep.c, i386-linux-nat.c, i386-linux-tdep.c, i386-tdep.c, i387-tdep.c, ia64-libunwind-tdep.c, ia64-linux-nat.c, inf-child.c, inf-ptrace.c, infcall.c, infcall.h, infcmd.c, inferior-iter.h, inferior.c, inferior.h, inflow.c, inflow.h, infrun.c, infrun.h, inline-frame.c, language.h, linespec.c, linux-fork.c, linux-nat.c, linux-tdep.c, linux-thread-db.c, location.c, machoread.c, macrotab.h, main.c, maint.c, maint.h, memattr.c, memrange.h, mi/mi-cmd-break.h, mi/mi-cmd-env.c, mi/mi-cmd-stack.c, mi/mi-cmd-var.c, mi/mi-interp.c, mi/mi-main.c, mi/mi-parse.h, minsyms.c, mips-linux-tdep.c, namespace.h, nat/aarch64-linux-hw-point.c, nat/aarch64-linux-hw-point.h, nat/aarch64-linux.c, nat/aarch64-sve-linux-ptrace.c, nat/amd64-linux-siginfo.c, nat/fork-inferior.c, nat/linux-btrace.c, nat/linux-btrace.h, nat/linux-namespaces.c, nat/linux-nat.h, nat/linux-osdata.c, nat/linux-personality.c, nat/linux-procfs.c, nat/linux-ptrace.c, nat/linux-ptrace.h, nat/linux-waitpid.c, nat/mips-linux-watch.c, nat/mips-linux-watch.h, nat/ppc-linux.c, nat/x86-dregs.c, nat/x86-dregs.h, nat/x86-linux-dregs.c, nat/x86-linux.c, nto-procfs.c, nto-tdep.c, objfile-flags.h, objfiles.c, objfiles.h, obsd-nat.c, observable.h, osdata.c, p-valprint.c, parse.c, parser-defs.h, ppc-linux-nat.c, printcmd.c, probe.c, proc-api.c, procfs.c, producer.c, progspace.h, psymtab.h, python/py-framefilter.c, python/py-inferior.c, python/py-ref.h, python/py-type.c, python/python.c, record-btrace.c, record-full.c, record.c, record.h, regcache-dump.c, regcache.c, regcache.h, remote-fileio.c, remote-fileio.h, remote-sim.c, remote.c, riscv-tdep.c, rs6000-aix-tdep.c, rust-exp.y, s12z-tdep.c, selftest-arch.c, ser-base.c, ser-event.c, ser-pipe.c, ser-tcp.c, ser-unix.c, skip.c, solib-aix.c, solib-target.c, solib.c, source-cache.c, source.c, source.h, sparc-nat.c, spu-linux-nat.c, stack.c, stap-probe.c, symfile-add-flags.h, symfile.c, symfile.h, symtab.c, symtab.h, target-descriptions.c, target-descriptions.h, target-memory.c, target.c, target.h, target/waitstatus.c, target/waitstatus.h, thread-iter.h, thread.c, tilegx-tdep.c, top.c, top.h, tracefile-tfile.c, tracefile.c, tracepoint.c, tracepoint.h, tui/tui-io.c, ui-file.c, ui-out.h, unittests/array-view-selftests.c, unittests/child-path-selftests.c, unittests/cli-utils-selftests.c, unittests/common-utils-selftests.c, unittests/copy_bitwise-selftests.c, unittests/environ-selftests.c, unittests/format_pieces-selftests.c, unittests/function-view-selftests.c, unittests/lookup_name_info-selftests.c, unittests/memory-map-selftests.c, unittests/memrange-selftests.c, unittests/mkdir-recursive-selftests.c, unittests/observable-selftests.c, unittests/offset-type-selftests.c, unittests/optional-selftests.c, unittests/parse-connection-spec-selftests.c, unittests/ptid-selftests.c, unittests/rsp-low-selftests.c, unittests/scoped_fd-selftests.c, unittests/scoped_mmap-selftests.c, unittests/scoped_restore-selftests.c, unittests/string_view-selftests.c, unittests/style-selftests.c, unittests/tracepoint-selftests.c, unittests/unpack-selftests.c, unittests/utils-selftests.c, unittests/xml-utils-selftests.c, utils.c, utils.h, valarith.c, valops.c, valprint.c, value.c, value.h, varobj.c, varobj.h, windows-nat.c, x86-linux-nat.c, xml-support.c, xml-support.h, xml-tdesc.h, xstormy16-tdep.c, xtensa-linux-nat.c, dwarf2read.h: Change common to gdbsupport. gdb/gdbserver/ChangeLog 2019-07-09 Tom Tromey <tom@tromey.com> * configure: Rebuild. * configure.ac: Change common to gdbsupport. * acinclude.m4: Change common to gdbsupport. * Makefile.in (SFILES, OBS, GDBREPLAY_OBS, IPA_OBJS) (version-generated.c, gdbsupport/%-ipa.o, gdbsupport/%.o): Change common to gdbsupport. * ax.c, event-loop.c, fork-child.c, gdb_proc_service.h, gdbreplay.c, gdbthread.h, hostio-errno.c, hostio.c, i387-fp.c, inferiors.c, inferiors.h, linux-aarch64-tdesc-selftest.c, linux-amd64-ipa.c, linux-i386-ipa.c, linux-low.c, linux-tic6x-low.c, linux-x86-low.c, linux-x86-tdesc-selftest.c, linux-x86-tdesc.c, lynx-i386-low.c, lynx-low.c, mem-break.h, nto-x86-low.c, regcache.c, regcache.h, remote-utils.c, server.c, server.h, spu-low.c, symbol.c, target.h, tdesc.c, tdesc.h, thread-db.c, tracepoint.c, win32-i386-low.c, win32-low.c: Change common to gdbsupport.
2019-05-06 04:29:24 +02:00
#include "gdbsupport/common-defs.h"
#include "waitstatus.h"
Fix internal error and improve 'set debug infrun 1'/target wait kind trace The test gdb.threads/watchthreads-reorder.exp verifies that the 'set debug infrun 1' debug output does not crash GDB. Under high load, the test can still cause a GDB internal error (see details below). This patch fixes this crash, and improves/factorises some wait kind traces. Tested on debian/amd64 + run one test with 'set debug infrun 1'. Changes compared to the first version: * Handles the suggestions of Kevin to trace the relevant elements of the wait status (this is done by calling target_waitstatus_to_string). * Some other changes to factorise wait status tracing. Note that using target_waitstatus_to_string instead of the 'locally printed' status kind strings means that debug trace that was using strings such as: "EXITED" or "TARGET_WAITKIND_EXITED" will now use what is printed by target_waitstatus_to_string e.g. "exited". gdb/ChangeLog 2019-04-01 Philippe Waroquiers <philippe.waroquiers@skynet.be> * infrun.c (stop_all_threads): If debug_infrun, always trace the wait status after wait_one, using target_waitstatus_to_string and target_pid_to_str. (handle_inferior_event): Replace various trace of wait status kind by a single trace. * gdb/gnu-nat.c (gnu_nat_target::wait): Replace local wait status kind image by target_waitstatus_to_string. * target/waitstatus.c (target_waitstatus_to_string): Fix obsolete comment. (top-gdb) bt #0 __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:51 #1 0x00007f3d54a0642a in __GI_abort () at abort.c:89 #2 0x0000555c24c60e66 in dump_core () at ../../fixleaks/gdb/utils.c:201 #3 0x0000555c24c63d49 in internal_vproblem(internal_problem *, const char *, int, const char *, typedef __va_list_tag __va_list_tag *) (problem=problem@entry=0x555c25338d40 <internal_error_problem>, file=<optimized out>, line=287, fmt=<optimized out>, ap=<optimized out>) at ../../fixleaks/gdb/utils.c:411 #4 0x0000555c24c63eab in internal_verror (file=<optimized out>, line=<optimized out>, fmt=<optimized out>, ap=<optimized out>) at ../../fixleaks/gdb/utils.c:436 #5 0x0000555c249e8c22 in internal_error (file=file@entry=0x555c24e0f2ad "../../fixleaks/gdb/inferior.c", line=line@entry=287, fmt=<optimized out>) at ../../fixleaks/gdb/common/errors.c:55 #6 0x0000555c247d3f5c in find_inferior_pid (pid=<optimized out>) at ../../fixleaks/gdb/inferior.c:287 #7 0x0000555c24ad2248 in find_inferior_pid (pid=<optimized out>) at ../../fixleaks/gdb/inferior.c:302 #8 find_inferior_ptid (ptid=...) at ../../fixleaks/gdb/inferior.c:301 #9 0x0000555c24c35f25 in find_thread_ptid (ptid=...) at ../../fixleaks/gdb/thread.c:522 #10 0x0000555c24b0ab4d in thread_db_target::pid_to_str[abi:cxx11](ptid_t) ( this=0x555c2532e3e0 <the_thread_db_target>, ptid=...) at ../../fixleaks/gdb/linux-thread-db.c:1637 #11 0x0000555c24c2f420 in target_pid_to_str[abi:cxx11](ptid_t) (ptid=...) at ../../fixleaks/gdb/target.c:2083 #12 0x0000555c24ad9cab in stop_all_threads () at ../../fixleaks/gdb/infrun.c:4373 #13 0x0000555c24ada00f in stop_waiting (ecs=<optimized out>) at ../../fixleaks/gdb/infrun.c:7464 #14 0x0000555c24adc401 in process_event_stop_test (ecs=ecs@entry=0x7ffc9402d9d0) at ../../fixleaks/gdb/infrun.c:6181 ... (top-gdb) fr 12 #12 0x0000555c24ad9cab in stop_all_threads () at ../../fixleaks/gdb/infrun.c:4373 (top-gdb) p event_ptid $5 = {m_pid = 25419, m_lwp = 25427, m_tid = 0} (top-gdb) p ptid $6 = {m_pid = 0, m_lwp = 0, m_tid = 0} (top-gdb) p ws $7 = {kind = TARGET_WAITKIND_THREAD_EXITED, value = {integer = 0, sig = GDB_SIGNAL_0, related_pid = {m_pid = 0, m_lwp = 0, m_tid = 0}, execd_pathname = 0x0, syscall_number = 0}} (top-gdb) The gdb.log corresponding to the above crash is: (gdb) PASS: gdb.threads/watchthreads-reorder.exp: reorder1: set debug infrun 1 continue Continuing. infrun: clear_proceed_status_thread (Thread 0x7ffff7fcfb40 (LWP 25419)) infrun: clear_proceed_status_thread (Thread 0x7ffff7310700 (LWP 25427)) infrun: clear_proceed_status_thread (Thread 0x7ffff6b0f700 (LWP 25428)) infrun: proceed (addr=0xffffffffffffffff, signal=GDB_SIGNAL_DEFAULT) infrun: proceed: resuming Thread 0x7ffff7fcfb40 (LWP 25419) infrun: resume (step=0, signal=GDB_SIGNAL_0), trap_expected=0, current thread [Thread 0x7ffff7fcfb40 (LWP 25419)] at 0x7ffff7344317 infrun: infrun_async(1) infrun: prepare_to_wait infrun: proceed: resuming Thread 0x7ffff7310700 (LWP 25427) infrun: resume (step=0, signal=GDB_SIGNAL_0), trap_expected=0, current thread [Thread 0x7ffff7310700 (LWP 25427)] at 0x5555555553d7 infrun: prepare_to_wait infrun: proceed: resuming Thread 0x7ffff6b0f700 (LWP 25428) infrun: resume (step=0, signal=GDB_SIGNAL_0), trap_expected=0, current thread [Thread 0x7ffff6b0f700 (LWP 25428)] at 0x5555555554c8 infrun: prepare_to_wait infrun: target_wait (-1.0.0, status) = infrun: -1.0.0 [process -1], infrun: status->kind = ignore infrun: TARGET_WAITKIND_IGNORE infrun: prepare_to_wait Joining the threads. [Thread 0x7ffff6b0f700 (LWP 25428) exited] infrun: target_wait (-1.0.0, status) = infrun: -1.0.0 [process -1], infrun: status->kind = ignore infrun: TARGET_WAITKIND_IGNORE infrun: prepare_to_wait infrun: target_wait (-1.0.0, status) = infrun: 25419.25419.0 [Thread 0x7ffff7fcfb40 (LWP 25419)], infrun: status->kind = stopped, signal = GDB_SIGNAL_TRAP infrun: TARGET_WAITKIND_STOPPED infrun: stop_pc = 0x555555555e50 infrun: context switch infrun: Switching context from Thread 0x7ffff6b0f700 (LWP 25428) to Thread 0x7ffff7fcfb40 (LWP 25419) infrun: BPSTAT_WHAT_STOP_NOISY infrun: stop_waiting infrun: stop_all_threads infrun: stop_all_threads, pass=0, iterations=0 infrun: Thread 0x7ffff7fcfb40 (LWP 25419) not executing infrun: Thread 0x7ffff7310700 (LWP 25427) executing, need stop [Thread 0x7ffff7310700 (LWP 25427) exited] infrun: target_wait (-1.0.0, status) = infrun: 25419.25427.0 [LWP 25427], infrun: status->kind = thread exited, status = 0 infrun: infrun_async(0) ../../fixleaks/gdb/inferior.c:287: internal-error: inferior* find_inferior_pid(int): Assertion `pid != 0' failed. A problem internal to GDB has been detected, further debugging may prove unreliable. Quit this debugging session? (y or n) FAIL: gdb.threads/watchthreads-reorder.exp: reorder1: continue to breakpoint: break-at-exit (GDB internal error) Resyncing due to internal error. n infrun: infrun_async(1) This is a bug, please report it. For instructions, see: <http://www.gnu.org/software/gdb/bugs/>. infrun: infrun_async(0) ../../fixleaks/gdb/inferior.c:287: internal-error: inferior* find_inferior_pid(int): Assertion `pid != 0' failed. A problem internal to GDB has been detected, further debugging may prove unreliable. Create a core file of GDB? (y or n) y
2019-03-24 15:14:55 +01:00
/* Return a pretty printed form of target_waitstatus. */
std::string
target_waitstatus_to_string (const struct target_waitstatus *ws)
{
const char *kind_str = "status->kind = ";
switch (ws->kind)
{
case TARGET_WAITKIND_EXITED:
return string_printf ("%sexited, status = %d",
kind_str, ws->value.integer);
case TARGET_WAITKIND_STOPPED:
return string_printf ("%sstopped, signal = %s",
kind_str,
gdb_signal_to_symbol_string (ws->value.sig));
case TARGET_WAITKIND_SIGNALLED:
return string_printf ("%ssignalled, signal = %s",
kind_str,
gdb_signal_to_symbol_string (ws->value.sig));
case TARGET_WAITKIND_LOADED:
return string_printf ("%sloaded", kind_str);
case TARGET_WAITKIND_FORKED:
return string_printf ("%sforked", kind_str);
case TARGET_WAITKIND_VFORKED:
return string_printf ("%svforked", kind_str);
case TARGET_WAITKIND_EXECD:
return string_printf ("%sexecd", kind_str);
case TARGET_WAITKIND_VFORK_DONE:
return string_printf ("%svfork-done", kind_str);
case TARGET_WAITKIND_SYSCALL_ENTRY:
return string_printf ("%sentered syscall", kind_str);
case TARGET_WAITKIND_SYSCALL_RETURN:
return string_printf ("%sexited syscall", kind_str);
case TARGET_WAITKIND_SPURIOUS:
return string_printf ("%sspurious", kind_str);
case TARGET_WAITKIND_IGNORE:
return string_printf ("%signore", kind_str);
case TARGET_WAITKIND_NO_HISTORY:
return string_printf ("%sno-history", kind_str);
case TARGET_WAITKIND_NO_RESUMED:
return string_printf ("%sno-resumed", kind_str);
Remote thread create/exit events When testing with "maint set target-non-stop on", a few threading-related tests expose an issue that requires new RSP packets. Say there are 3 threads running, 1-3. If GDB tries to stop thread 1, 2 and 3, and then waits for their stops, but meanwhile say, thread 2 exits, GDB hangs forever waiting for a stop for thread 2 that won't ever happen. This patch fixes the issue by adding support for thread exit events to the protocol. However, we don't want these always enabled, as they're useless most of the time, and would slow down remote debugging. So I made it so that GDB can enable/disable them, and then made gdb do that around the cases that need it, which currently is only infrun.c:stop_all_threads. In turn, if we have thread exit events, then the extra "thread x exited" traffic slows down attach-many-short-lived-threads.exp enough that gdb has trouble keeping up with new threads that are spawned while gdb tries to stop existing ones. To fix that I added support for the counterpart thread created events too. Enabling those when we try to stop threads ensures that new threads never get a chance to themselves start new threads, killing the race. gdb/doc/ChangeLog: 2015-11-30 Pedro Alves <palves@redhat.com> * gdb.texinfo (Remote Configuration): List "set/show remote thread-events" command in configuration table. (Stop Reply Packets): Document "T05 create" stop reason and 'w' stop reply. (General Query Packets): Document QThreadEvents packet. Document QThreadEvents qSupported feature. gdb/gdbserver/ChangeLog: 2015-11-30 Pedro Alves <palves@redhat.com> * linux-low.c (handle_extended_wait): Assert that the LWP's waitstatus is TARGET_WAITKIND_IGNORE. If GDB wants to hear about thread create events, leave the new child's status pending. (linux_low_filter_event): If GDB wants to hear about thread exit events, leave the LWP marked dead and don't delete it. (linux_wait_for_event_filtered): Don't check for thread exit. (filter_exit_event): New function. (linux_wait_1): Use it, when returning an exit event. (linux_resume_one_lwp_throw): Assert that the LWP's waitstatus is TARGET_WAITKIND_IGNORE. * remote-utils.c (prepare_resume_reply): Handle TARGET_WAITKIND_THREAD_CREATED and TARGET_WAITKIND_THREAD_EXITED. * server.c (report_thread_events): New global. (handle_general_set): Handle QThreadEvents. (handle_query) <qSupported>: Handle and report QThreadEvents+; (handle_target_event): Handle TARGET_WAITKIND_THREAD_CREATED and TARGET_WAITKIND_THREAD_EXITED. * server.h (report_thread_events): Declare. gdb/ChangeLog: 2015-11-30 Pedro Alves <palves@redhat.com> * NEWS (New commands): Mention "set/show remote thread-events" commands. (New remote packets): Mention thread created/exited stop reasons and QThreadEvents packet. * infrun.c (disable_thread_events): New function. (stop_all_threads): Disable/enable thread create/exit events. Handle TARGET_WAITKIND_THREAD_EXITED. (handle_inferior_event_1): Handle TARGET_WAITKIND_THREAD_CREATED and TARGET_WAITKIND_THREAD_EXITED. * remote.c (remove_child_of_pending_fork): Also remove threads of threads that have TARGET_WAITKIND_THREAD_EXITED events. (remote_parse_stop_reply): Handle "create" magic register. Handle 'w' stop reply. (initialize_remote): Install remote_thread_events as to_thread_events target hook. (remote_thread_events): New function. * target-delegates.c: Regenerate. * target.c (target_thread_events): New function. * target.h (struct target_ops) <to_thread_events>: New field. (target_thread_events): Declare. * target/waitstatus.c (target_waitstatus_to_string): Handle TARGET_WAITKIND_THREAD_CREATED and TARGET_WAITKIND_THREAD_EXITED. * target/waitstatus.h (enum target_waitkind) <TARGET_WAITKIND_THREAD_CREATED, TARGET_WAITKIND_THREAD_EXITED): New values.
2015-11-30 17:05:21 +01:00
case TARGET_WAITKIND_THREAD_CREATED:
return string_printf ("%sthread created", kind_str);
Remote thread create/exit events When testing with "maint set target-non-stop on", a few threading-related tests expose an issue that requires new RSP packets. Say there are 3 threads running, 1-3. If GDB tries to stop thread 1, 2 and 3, and then waits for their stops, but meanwhile say, thread 2 exits, GDB hangs forever waiting for a stop for thread 2 that won't ever happen. This patch fixes the issue by adding support for thread exit events to the protocol. However, we don't want these always enabled, as they're useless most of the time, and would slow down remote debugging. So I made it so that GDB can enable/disable them, and then made gdb do that around the cases that need it, which currently is only infrun.c:stop_all_threads. In turn, if we have thread exit events, then the extra "thread x exited" traffic slows down attach-many-short-lived-threads.exp enough that gdb has trouble keeping up with new threads that are spawned while gdb tries to stop existing ones. To fix that I added support for the counterpart thread created events too. Enabling those when we try to stop threads ensures that new threads never get a chance to themselves start new threads, killing the race. gdb/doc/ChangeLog: 2015-11-30 Pedro Alves <palves@redhat.com> * gdb.texinfo (Remote Configuration): List "set/show remote thread-events" command in configuration table. (Stop Reply Packets): Document "T05 create" stop reason and 'w' stop reply. (General Query Packets): Document QThreadEvents packet. Document QThreadEvents qSupported feature. gdb/gdbserver/ChangeLog: 2015-11-30 Pedro Alves <palves@redhat.com> * linux-low.c (handle_extended_wait): Assert that the LWP's waitstatus is TARGET_WAITKIND_IGNORE. If GDB wants to hear about thread create events, leave the new child's status pending. (linux_low_filter_event): If GDB wants to hear about thread exit events, leave the LWP marked dead and don't delete it. (linux_wait_for_event_filtered): Don't check for thread exit. (filter_exit_event): New function. (linux_wait_1): Use it, when returning an exit event. (linux_resume_one_lwp_throw): Assert that the LWP's waitstatus is TARGET_WAITKIND_IGNORE. * remote-utils.c (prepare_resume_reply): Handle TARGET_WAITKIND_THREAD_CREATED and TARGET_WAITKIND_THREAD_EXITED. * server.c (report_thread_events): New global. (handle_general_set): Handle QThreadEvents. (handle_query) <qSupported>: Handle and report QThreadEvents+; (handle_target_event): Handle TARGET_WAITKIND_THREAD_CREATED and TARGET_WAITKIND_THREAD_EXITED. * server.h (report_thread_events): Declare. gdb/ChangeLog: 2015-11-30 Pedro Alves <palves@redhat.com> * NEWS (New commands): Mention "set/show remote thread-events" commands. (New remote packets): Mention thread created/exited stop reasons and QThreadEvents packet. * infrun.c (disable_thread_events): New function. (stop_all_threads): Disable/enable thread create/exit events. Handle TARGET_WAITKIND_THREAD_EXITED. (handle_inferior_event_1): Handle TARGET_WAITKIND_THREAD_CREATED and TARGET_WAITKIND_THREAD_EXITED. * remote.c (remove_child_of_pending_fork): Also remove threads of threads that have TARGET_WAITKIND_THREAD_EXITED events. (remote_parse_stop_reply): Handle "create" magic register. Handle 'w' stop reply. (initialize_remote): Install remote_thread_events as to_thread_events target hook. (remote_thread_events): New function. * target-delegates.c: Regenerate. * target.c (target_thread_events): New function. * target.h (struct target_ops) <to_thread_events>: New field. (target_thread_events): Declare. * target/waitstatus.c (target_waitstatus_to_string): Handle TARGET_WAITKIND_THREAD_CREATED and TARGET_WAITKIND_THREAD_EXITED. * target/waitstatus.h (enum target_waitkind) <TARGET_WAITKIND_THREAD_CREATED, TARGET_WAITKIND_THREAD_EXITED): New values.
2015-11-30 17:05:21 +01:00
case TARGET_WAITKIND_THREAD_EXITED:
return string_printf ("%sthread exited, status = %d",
kind_str, ws->value.integer);
default:
return string_printf ("%sunknown???", kind_str);
}
}