In my multi-target branch I ran into problems with GDB's terminal
handling that exist in master as well, with multi-inferior debugging.
This patch adds a testcase for said problems
(gdb.multi/multi-term-settings.exp), fixes the problems, fixes PR
gdb/13211 as well (and adds a testcase for that too,
gdb.base/interrupt-daemon.exp).
The basis of the problem I ran into is the following. Consider a
scenario where you have:
- inferior 1 - started with "attach", process is running on some
other terminal.
- inferior 2 - started with "run", process is sharing gdb's terminal.
In this scenario, when you stop/resume both inferiors, you want GDB to
save/restore the terminal settings of inferior 2, the one that is
sharing GDB's terminal. I.e., you want inferior 2 to "own" the
terminal (in target_terminal::is_ours/target_terminal::is_inferior
sense).
Unfortunately, that's not what you get currently. Because GDB doesn't
know whether an attached inferior is actually sharing GDB's terminal,
it tries to save/restore its settings anyway, ignoring errors. In
this case, this is pointless, because inferior 1 is running on a
different terminal, but GDB doesn't know better.
And then, because it is only possible to have the terminal settings of
a single inferior be in effect at a time, or make one inferior/pgrp be
the terminal's foreground pgrp (aka, only one inferior can "own" the
terminal, ignoring fork children here), if GDB happens to try to
restore the terminal settings of inferior 1 first, then GDB never
restores the terminal settings of inferior 2.
This patch fixes that and a few things more along the way:
- Moves enum target_terminal::terminal_state out of the
target_terminal class (it's currently private) and makes it a
scoped enum so that it can be easily used elsewhere.
- Replaces the inflow.c:terminal_is_ours boolean with a
target_terminal_state variable. This allows distinguishing is_ours
and is_ours_for_output states. This allows finally making
child_terminal_ours_1 do something with its "output_only"
parameter.
- Makes each inferior have its own copy of the
is_ours/is_ours_for_output/is_inferior state.
- Adds a way for GDB to tell whether the inferior is sharing GDB's
terminal. Works best on Linux and Solaris; the fallback works just
as well as currently.
- With that, we can remove the inf->attach_flag tests from
child_terminal_inferior/child_terminal_ours.
- Currently target_ops.to_ours is responsible for both saving the
current inferior's terminal state, and restoring gdb's state.
Because each inferior has its own terminal state (possibly handled
by different targets in a multi-target world, even), we need to
split the inferior-saving part from the gdb-restoring part. The
patch adds a new target_ops.to_save_inferior target method for
that.
- Adds a new target_terminal::save_inferior() function, so that
sequences like:
scoped_restore_terminal_state save_state;
target_terminal::ours_for_output ();
... restore back inferiors that were
target_terminal_state::is_inferior before back to is_inferior, and
leaves inferiors that were is_ours alone.
- Along the way, this adds a default implementation of
target_pass_ctrlc to inflow.c (for inf-child.c), that handles
passing the Ctrl-C to a process running on GDB's terminal or to
some other process otherwise.
- Similarly, adds a new target default implementation of
target_interrupt, for the "interrupt" command. The current
implementation of this hook in inf-ptrace.c kills the whole process
group, but that's incorrect/undesirable because we may not be
attached to all processes in the process group. And also, it's
incorrect because inferior_process_group() doesn't really return
the inferior's real process group id if the inferior is not a
process group leader... This is the cause of PR gdb/13211 [1],
which this patch fixes. While at it, that target method's "ptid"
parameter is eliminated, because it's not really used.
- A new test is included that exercises and fixes PR gdb/13211, and
also fixes a GDB issue reported on stackoverflow that I ran into
while working on this [2]. The problem is similar to PR gdb/13211,
except that it also triggers with Ctrl-C. When debugging a daemon
(i.e., a process that disconnects from the controlling terminal and
is not a process group leader, then Ctrl-C doesn't work, you just
can't interrupt the inferior at all, resulting in a hung debug
session. The problem is that since the inferior is no longer
associated with gdb's session / controlling terminal, then trying
to put the inferior in the foreground fails. And so Ctrl-C never
reaches the inferior directly. pass_signal is only used when the
inferior is attached, but that is not the case here. This is fixed
by the new child_pass_ctrlc. Without the fix, the new
interrupt-daemon.exp testcase fails with timeout waiting for a
SIGINT that never arrives.
[1] PR gdb/13211 - Async / Process group and interrupt not working
https://sourceware.org/bugzilla/show_bug.cgi?id=13211
[2] GDB not reacting Ctrl-C when after fork() and setsid()
https://stackoverflow.com/questions/46101292/gdb-not-reacting-ctrl-c-when-after-fork-and-setsid
Note this patch does _not_ fix:
- PR gdb/14559 - The 'interrupt' command does not work if sigwait is in use
https://sourceware.org/bugzilla/show_bug.cgi?id=14559
- PR gdb/9425 - When using "sigwait" GDB doesn't trap SIGINT. Ctrl+C terminates program when should break gdb.
https://sourceware.org/bugzilla/show_bug.cgi?id=9425
The only way to fix that that I know of (without changing the kernel)
is to make GDB put inferiors in a separate session (create a
pseudo-tty master/slave pair, make the inferior run with the slave as
its terminal, and have gdb pump output/input on the master end).
gdb/ChangeLog:
2018-01-30 Pedro Alves <palves@redhat.com>
PR gdb/13211
* config.in, configure: Regenerate.
* configure.ac: Check for getpgid.
* go32-nat.c (go32_pass_ctrlc): New.
(go32_target): Install it.
* inf-child.c (inf_child_target): Install
child_terminal_save_inferior, child_pass_ctrlc and
child_interrupt.
* inf-ptrace.c (inf_ptrace_interrupt): Delete.
(inf_ptrace_target): No longer install it.
* infcmd.c (interrupt_target_1): Adjust.
* inferior.h (child_terminal_save_inferior, child_pass_ctrlc)
(child_interrupt): Declare.
(inferior::terminal_state): New.
* inflow.c (struct terminal_info): Update comments.
(inferior_process_group): Delete.
(terminal_is_ours): Delete.
(gdb_tty_state): New.
(child_terminal_init): Adjust.
(is_gdb_terminal, sharing_input_terminal_1)
(sharing_input_terminal): New functions.
(child_terminal_inferior): Adjust. Use sharing_input_terminal.
Set the process's actual process group in the foreground if
possible. Handle is_ours_for_output/is_ours distinction. Don't
mark terminal as the inferior's if not sharing GDB's terminal.
Don't check attach_flag.
(child_terminal_ours_for_output, child_terminal_ours): Adjust to
pass down a target_terminal_state.
(child_terminal_save_inferior): New, factored out from ...
(child_terminal_ours_1): ... this. Handle
target_terminal_state::is_ours_for_output.
(child_interrupt, child_pass_ctrlc): New.
(inflow_inferior_exit): Clear the inferior's terminal_state.
(copy_terminal_info): Copy the inferior's terminal state.
(_initialize_inflow): Remove reference to terminal_is_ours.
* inflow.h (inferior_process_group): Delete.
* nto-procfs.c (nto_handle_sigint, procfs_interrupt): Adjust.
* procfs.c (procfs_target): Don't install procfs_interrupt.
(procfs_interrupt): Delete.
* remote.c (remote_serial_quit_handler): Adjust.
(remote_interrupt): Remove ptid parameter. Adjust.
* target-delegates.c: Regenerate.
* target.c: Include "terminal.h".
(target_terminal::terminal_state): Rename to ...
(target_terminal::m_terminal_state): ... this.
(target_terminal::init): Adjust.
(target_terminal::inferior): Adjust to per-inferior
terminal_state.
(target_terminal::restore_inferior, target_terminal_is_ours_kind): New.
(target_terminal::ours, target_terminal::ours_for_output): Use
target_terminal_is_ours_kind.
(target_interrupt): Remove ptid parameter. Adjust.
(default_target_pass_ctrlc): Adjust.
* target.h (target_ops::to_terminal_save_inferior): New field.
(target_ops::to_interrupt): Remove ptid_t parameter.
(target_interrupt): Remove ptid_t parameter. Update comment.
(target_pass_ctrlc): Update comment.
* target/target.h (target_terminal_state): New scoped enum,
factored out of ...
(target_terminal::terminal_state): ... here.
(target_terminal::inferior): Update comments.
(target_terminal::restore_inferior): New.
(target_terminal::is_inferior, target_terminal::is_ours)
(target_terminal::is_ours_for_output): Adjust.
(target_terminal::scoped_restore_terminal_state): Adjust to
rename, and call restore_inferior() instead of inferior().
(target_terminal::scoped_restore_terminal_state::m_state): Change
type.
(target_terminal::terminal_state): Rename to ...
(target_terminal::m_terminal_state): ... this and change type.
gdb/gdbserver/ChangeLog:
2018-01-30 Pedro Alves <palves@redhat.com>
PR gdb/13211
* target.c (target_terminal::terminal_state): Rename to ...
(target_terminal::m_terminal_state): ... this.
gdb/testsuite/ChangeLog:
2018-01-30 Pedro Alves <palves@redhat.com>
PR gdb/13211
* gdb.base/interrupt-daemon.c: New.
* gdb.base/interrupt-daemon.exp: New.
* gdb.multi/multi-term-settings.c: New.
* gdb.multi/multi-term-settings.exp: New.
A quite straightforward change. It does "fix" leaks in record-btrace.c,
although since this is only used in debug printing code, it has no real
world impact.
gdb/ChangeLog:
* target/waitstatus.h (target_waitstatus_to_string): Change
return type to std::string.
* target/waitstatus.c (target_waitstatus_to_string): Return
std::string.
* target.h (target_waitstatus_to_string): Remove declaration.
* infrun.c (resume, clear_proceed_status_thread,
print_target_wait_results, do_target_wait, save_waitstatus,
stop_all_threads): Adjust.
* record-btrace.c (record_btrace_wait): Adjust.
* target-debug.h
(target_debug_print_struct_target_waitstatus_p): Adjust.
gdb/gdbserver/ChangeLog:
* linux-low.c (linux_wait_1): Adjust.
* server.c (queue_stop_reply_callback): Adjust.
This is the most important (and the biggest, sorry) patch of the
series. It moves fork_inferior from gdb/fork-child.c to
nat/fork-inferior.c and makes all the necessary adjustments to both
GDB and gdbserver to make sure everything works OK.
There is no "most important change" with this patch; all changes are
made in a progressive way, making sure that gdbserver had the
necessary features while not breaking GDB at the same time.
I decided to go ahead and implement a partial support for starting the
inferior with a shell on gdbserver, although the full feature comes in
the next patch. The user won't have the option to disable the
startup-with-shell, and also won't be able to change which shell
gdbserver will use (other than setting the $SHELL environment
variable, that is).
Everything is working as expected, and no regressions were present
during the tests.
gdb/ChangeLog:
2017-06-07 Sergio Durigan Junior <sergiodj@redhat.com>
Pedro Alves <palves@redhat.com>
* Makefile.in (HFILES_NO_SRCDIR): Add "common/common-inferior.h"
and "nat/fork-inferior.h".
* common/common-inferior.h: New file, with contents from
"gdb/inferior.h".
* commom/common-utils.c: Include "common-utils.h".
(stringify_argv): New function.
* common/common-utils.h (stringify_argv): New prototype.
* configure.nat: Add "fork-inferior.o" as a dependency for
"*linux*", "fbsd*" and "nbsd*" hosts.
* corefile.c (get_exec_file): Update comment.
* darwin-nat.c (darwin_ptrace_him): Call "gdb_startup_inferior"
instead of "startup_inferior".
(darwin_create_inferior): Call "add_thread_silent" after
"fork_inferior".
* fork-child.c: Cleanup unnecessary includes.
(SHELL_FILE): Move to "common/common-fork-child.c".
(environ): Likewise.
(exec_wrapper): Initialize.
(get_exec_wrapper): New function.
(breakup_args): Move to "common/common-fork-child.c"; rename to
"breakup_args_for_exec".
(escape_bang_in_quoted_argument): Move to
"common/common-fork-child.c".
(saved_ui): New variable.
(prefork_hook): New function.
(postfork_hook): Likewise.
(postfork_child_hook): Likewise.
(gdb_startup_inferior): Likewise.
(fork_inferior): Move to "common/common-fork-child.c". Update
function to support gdbserver.
(startup_inferior): Likewise.
* gdbcore.h (get_exec_file): Remove declaration.
* gnu-nat.c (gnu_create_inferior): Call "gdb_startup_inferior"
instead of "startup_inferior". Call "add_thread_silent" after
"fork_inferior".
* inf-ptrace.c: Include "nat/fork-inferior.h" and "utils.h".
(inf_ptrace_create_inferior): Call "gdb_startup_inferior"
instead of "startup_inferior". Call "add_thread_silent" after
"fork_inferior".
* inferior.h: Include "common-inferior.h".
(trace_start_error): Move to "common/common-utils.h".
(trace_start_error_with_name): Likewise.
(fork_inferior): Move prototype to "nat/fork-inferior.h".
(startup_inferior): Likewise.
(gdb_startup_inferior): New prototype.
* nat/fork-inferior.c: New file, with contents from "fork-child.c".
* nat/fork-inferior.h: New file.
* procfs.c (procfs_init_inferior): Call "gdb_startup_inferior"
instead of "startup_inferior". Call "add_thread_silent" after
"fork_inferior".
* target.h (target_terminal_init): Move prototype to
"target/target.h".
(target_terminal_inferior): Likewise.
(target_terminal_ours): Likewise.
* target/target.h (target_terminal_init): New prototype, moved
from "target.h".
(target_terminal_inferior): Likewise.
(target_terminal_ours): Likewise.
* utils.c (gdb_flush_out_err): New function.
gdb/gdbserver/ChangeLog:
2017-06-07 Sergio Durigan Junior <sergiodj@redhat.com>
Pedro Alves <palves@redhat.com>
* Makefile.in (SFILES): Add "nat/fork-inferior.o".
* configure: Regenerate.
* configure.srv (srv_linux_obj): Add "fork-child.o" and
"fork-inferior.o".
(i[34567]86-*-lynxos*): Likewise.
(spu*-*-*): Likewise.
* fork-child.c: New file.
* linux-low.c: Include "common-inferior.h", "nat/fork-inferior.h"
and "environ.h".
(linux_ptrace_fun): New function.
(linux_create_inferior): Adjust function prototype to reflect
change on "target.h". Adjust function code to use
"fork_inferior".
(linux_request_interrupt): Delete "signal_pid".
* lynx-low.c: Include "common-inferior.h" and "nat/fork-inferior.h".
(lynx_ptrace_fun): New function.
(lynx_create_inferior): Adjust function prototype to reflect
change on "target.h". Adjust function code to use
"fork_inferior".
* nto-low.c (nto_create_inferior): Adjust function prototype and
code to reflect change on "target.h". Update comments.
* server.c: Include "common-inferior.h", "nat/fork-inferior.h",
"common-terminal.h" and "environ.h".
(terminal_fd): Moved to fork-child.c.
(old_foreground_pgrp): Likewise.
(restore_old_foreground_pgrp): Likewise.
(last_status): Make it global.
(last_ptid): Likewise.
(our_environ): New variable.
(startup_with_shell): Likewise.
(program_name): Likewise.
(program_argv): Rename to...
(program_args): ...this.
(wrapper_argv): New variable.
(start_inferior): Delete function.
(get_exec_wrapper): New function.
(get_exec_file): Likewise.
(get_environ): Likewise.
(prefork_hook): Likewise.
(post_fork_inferior): Likewise.
(postfork_hook): Likewise.
(postfork_child_hook): Likewise.
(handle_v_run): Update code to deal with arguments coming from the
remote host. Update calls from "start_inferior" to
"create_inferior".
(captured_main): Likewise. Initialize environment variable. Call
"have_job_control".
* server.h (post_fork_inferior): New prototype.
(get_environ): Likewise.
(last_status): Declare.
(last_ptid): Likewise.
(signal_pid): Likewise.
* spu-low.c: Include "common-inferior.h" and "nat/fork-inferior.h".
(spu_ptrace_fun): New function.
(spu_create_inferior): Adjust function prototype to reflect change
on "target.h". Adjust function code to use "fork_inferior".
* target.c (target_terminal_init): New function.
(target_terminal_inferior): Likewise.
(target_terminal_ours): Likewise.
* target.h: Include <vector>.
(struct target_ops) <create_inferior>: Update prototype.
(create_inferior): Update macro.
* utils.c (gdb_flush_out_err): New function.
* win32-low.c (win32_create_inferior): Adjust function prototype
and code to reflect change on "target.h".
gdb/testsuite/ChangeLog:
2017-06-07 Sergio Durigan Junior <sergiodj@redhat.com>
* gdb.server/non-existing-program.exp: Update regex in order to
reflect the fact that gdbserver is now using fork_inferior (with a
shell) to startup the inferior.
This applies the second part of GDB's End of Year Procedure, which
updates the copyright year range in all of GDB's files.
gdb/ChangeLog:
Update copyright year range in all GDB files.
This simple commit consolidates the API of
target_supports_multi_process. Since both GDB and gdbserver use the
same function prototype, all that was needed was to move create this
prototype on gdb/target/target.h and turn the macros declared on
gdb/{,gdbserver/}target.h into actual functions.
Regtested (clean pass) on the BuildBot.
gdb/ChangeLog:
2016-10-06 Sergio Durigan Junior <sergiodj@redhat.com>
* target.c (target_supports_multi_process): New function, moved
from...
* target.h (target_supports_multi_process): ... here. Remove
macro.
* target/target.h (target_supports_multi_process): New prototype.
gdb/gdbserver/ChangeLog:
2016-10-06 Sergio Durigan Junior <sergiodj@redhat.com>
* target.c (target_supports_multi_process): New function, moved
from...
* target.h (target_supports_multi_process): ... here. Remove
macro.
This patch consolidates the API of target_mourn_inferior between GDB
and gdbserver, in my continuing efforts to make sharing the
fork_inferior function possible between both.
GDB's version of the function did not care about the inferior's ptid
being mourned, but gdbserver's needed to know this information. Since
it actually makes sense to pass the ptid as an argument, instead of
depending on a global value directly (which GDB's version did), I
decided to make the generic API to accept it. I then went on and
extended all calls being made on GDB to include a ptid argument (which
ended up being inferior_ptid most of the times, anyway), and now we
have a more sane interface.
On GDB's side, after talking to Pedro a bit about it, we decided that
just an assertion to make sure that the ptid being passed is equal to
inferior_ptid would be enough for now, on the GDB side. We can remove
the assertion and perform more operations later if we ever pass
anything different than inferior_ptid.
Regression tested on our BuildBot, everything OK.
I'd appreciate a special look at gdb/windows-nat.c's modification
because I wasn't really sure what to do there. It seemed to me that
maybe I should build a ptid out of the process information there, but
then I am almost sure the assertion on GDB's side would trigger.
gdb/ChangeLog:
2016-09-19 Sergio Durigan Junior <sergiodj@redhat.com>
* darwin-nat.c (darwin_kill_inferior): Adjusting call to
target_mourn_inferior to include ptid_t argument.
* fork-child.c (startup_inferior): Likewise.
* gnu-nat.c (gnu_kill_inferior): Likewise.
* inf-ptrace.c (inf_ptrace_kill): Likewise.
* infrun.c (handle_inferior_event_1): Likewise.
* linux-nat.c (linux_nat_attach): Likewise.
(linux_nat_kill): Likewise.
* nto-procfs.c (interrupt_query): Likewise.
(procfs_interrupt): Likewise.
(procfs_kill_inferior): Likewise.
* procfs.c (procfs_kill_inferior): Likewise.
* record.c (record_mourn_inferior): Likewise.
* remote-sim.c (gdbsim_kill): Likewise.
* remote.c (remote_detach_1): Likewise.
(remote_kill): Likewise.
* target.c (target_mourn_inferior): Change declaration to accept
new ptid_t argument; use gdb_assert on it.
* target.h (target_mourn_inferior): Move function prototype from
here...
* target/target.h (target_mourn_inferior): ... to here. Adjust it
to accept new ptid_t argument.
* windows-nat.c (get_windows_debug_event): Adjusting call to
target_mourn_inferior to include ptid_t argument.
gdb/gdbserver/ChangeLog:
2016-09-19 Sergio Durigan Junior <sergiodj@redhat.com>
* server.c (start_inferior): Call target_mourn_inferior instead of
mourn_inferior; pass ptid_t argument to it.
(resume): Likewise.
(handle_target_event): Likewise.
* target.c (target_mourn_inferior): New function.
* target.h (mourn_inferior): Delete macro.
This commit moves the target_wait prototype from the GDB-specific
target.h header to the common target/target.h header. Then, it
creates a compatible implementation of target_wait on gdbserver using
the_target->wait, and adjusts the (only) caller (mywait function).
Pretty straightforward, no regressions introduced.
gdb/gdbserver/ChangeLog:
2016-09-01 Sergio Durigan Junior <sergiodj@redhat.com>
* target.c (mywait): Call target_wait instead of
the_target->wait.
(target_wait): New function.
gdb/ChangeLog:
2016-09-01 Sergio Durigan Junior <sergiodj@redhat.com>
* target.c (target_wait): Mention that the function's prototype
can be found at target/target.h.
* target.h (target_wait): Move prototype from here...
* target/target.h (target_wait): ... to here.
This commit implements a new function, target_continue, on top of the
target_resume function. Then, it replaces all calls to target_resume
by calls to target_continue or to the already existing
target_continue_no_signal.
This is one of the (many) necessary steps needed to consolidate the
target interface between GDB and gdbserver. In particular, I am
interested in the impact this change will have on the unification of
the fork_inferior function (which I have been working on).
Tested on the BuildBot, no regressions introduced.
gdb/gdbserver/ChangeLog:
2016-09-31 Sergio Durigan Junior <sergiodj@redhat.com>
* server.c (start_inferior): New variable 'ptid'. Replace calls
to the_target->resume by target_continue{,_no_signal}, depending
on the case.
* target.c (target_stop_and_wait): Call target_continue_no_signal
instead of the_target->resume.
(target_continue): New function.
gdb/ChangeLog:
2016-09-31 Sergio Durigan Junior <sergiodj@redhat.com>
* fork-child.c (startup_inferior): Replace calls to target_resume
by target_continue{,_no_signal}, depending on the case.
* linux-nat.c (cleanup_target_stop): Call
target_continue_no_signal instead of target_resume.
* procfs.c (procfs_wait): Likewise.
* target.c (target_continue): New function.
* target/target.h (target_continue): New prototype.
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.
Ref: https://sourceware.org/ml/gdb-patches/2015-07/msg00868.html
This adds a test that has a multithreaded program have several threads
continuously fork, while another thread continuously steps over a
breakpoint.
This exposes several intertwined issues, which this patch addresses:
- When we're stopping and suspending threads, some thread may fork,
and we missed setting its suspend count to 1, like we do when a new
clone/thread is detected. When we next unsuspend threads, the fork
child's suspend count goes below 0, which is bogus and fails an
assertion.
- If a step-over is cancelled because a signal arrives, but then gdb
is not interested in the signal, we pass the signal straight back
to the inferior. However, we miss that we need to re-increment the
suspend counts of all other threads that had been paused for the
step-over. As a result, other threads indefinitely end up stuck
stopped.
- If a detach request comes in just while gdbserver is handling a
step-over (in the test at hand, this is GDB detaching the fork
child), gdbserver internal errors in stabilize_thread's helpers,
which assert that all thread's suspend counts are 0 (otherwise we
wouldn't be able to move threads out of the jump pads). The
suspend counts aren't 0 while a step-over is in progress, because
all threads but the one stepping past the breakpoint must remain
paused until the step-over finishes and the breakpoint can be
reinserted.
- Occasionally, we see "BAD - reinserting but not stepping." being
output (from within linux_resume_one_lwp_throw). That was because
GDB pokes memory while gdbserver is busy with a step-over, and that
suspends threads, and then re-resumes them with proceed_one_lwp,
which missed another reason to tell linux_resume_one_lwp that the
thread should be set back to stepping.
- In a couple places, we were resuming threads that are meant to be
suspended. E.g., when a vCont;c/s request for thread B comes in
just while gdbserver is stepping thread A past a breakpoint. The
resume for thread B must be deferred until the step-over finishes.
- The test runs with both "set detach-on-fork" on and off. When off,
it exercises the case of GDB detaching the fork child explicitly.
When on, it exercises the case of gdb resuming the child
explicitly. In the "off" case, gdb seems to exponentially become
slower as new inferiors are created. This is _very_ noticeable as
with only 100 inferiors gdb is crawling already, which makes the
test take quite a bit to run. For that reason, I've disabled the
"off" variant for now.
gdb/ChangeLog:
2015-08-06 Pedro Alves <palves@redhat.com>
* target/waitstatus.h (enum target_stop_reason)
<TARGET_STOPPED_BY_SINGLE_STEP>: New value.
gdb/gdbserver/ChangeLog:
2015-08-06 Pedro Alves <palves@redhat.com>
* linux-low.c (handle_extended_wait): Set the fork child's suspend
count if stopping and suspending threads.
(check_stopped_by_breakpoint): If stopped by trace, set the LWP's
stop reason to TARGET_STOPPED_BY_SINGLE_STEP.
(linux_detach): Complete an ongoing step-over.
(lwp_suspended_inc, lwp_suspended_decr): New functions. Use
throughout.
(resume_stopped_resumed_lwps): Don't resume a suspended thread.
(linux_wait_1): If passing a signal to the inferior after
finishing a step-over, unsuspend and re-resume all lwps. If we
see a single-step event but the thread should be continuing, don't
pass the trap to gdb.
(stuck_in_jump_pad_callback, move_out_of_jump_pad_callback): Use
internal_error instead of gdb_assert.
(enqueue_pending_signal): New function.
(check_ptrace_stopped_lwp_gone): Add debug output.
(start_step_over): Use internal_error instead of gdb_assert.
(complete_ongoing_step_over): New function.
(linux_resume_one_thread): Don't resume a suspended thread.
(proceed_one_lwp): If the LWP is stepping over a breakpoint, reset
it stepping.
gdb/testsuite/ChangeLog:
2015-08-06 Pedro Alves <palves@redhat.com>
* gdb.threads/forking-threads-plus-breakpoint.exp: New file.
* gdb.threads/forking-threads-plus-breakpoint.c: New file.
This should be just a move with no changes.
gdb/ChangeLog
2015-07-15 Aleksandar Ristovski <aristovski@qnx.com
Jan Kratochvil <jan.kratochvil@redhat.com>
Move linux_find_memory_regions_full & co.
* linux-tdep.c (nat/linux-maps.h): Include.
(gdb_regex.h): Remove the include.
(enum filterflags, struct smaps_vmflags, read_mapping, decode_vmflags)
(mapping_is_anonymous_p, dump_mapping_p): Moved to nat/linux-maps.c.
(linux_find_memory_region_ftype): Moved typedef to nat/linux-maps.h.
(linux_find_memory_regions_full): Moved definition to nat/linux-maps.c.
* nat/linux-maps.c: Include ctype.h, target/target-utils.h, gdb_regex.h
and target/target.h.
(struct smaps_vmflags, read_mapping, decode_vmflags)
(mapping_is_anonymous_p, dump_mapping_p): Move from linux-tdep.c.
(linux_find_memory_regions_full): Move from linux-tdep.c.
* nat/linux-maps.h (read_mapping): New declaration.
(linux_find_memory_region_ftype, enum filterflags): Moved from
linux-tdep.c.
(linux_find_memory_regions_full): New declaration.
* target.c (target/target-utils.h): Include.
(read_alloc_pread_ftype): Moved typedef to target/target-utils.h.
(read_alloc, read_stralloc_func_ftype, read_stralloc): Moved
definitions to target/target-utils.c.
* target.h (target_fileio_read_stralloc): Move it to target/target.h.
* target/target-utils.c (read_alloc, read_stralloc): Move definitions
from target.c.
* target/target-utils.h (read_alloc_pread_ftype): New typedef.
(read_alloc): New declaration.
(read_stralloc_func_ftype): New typedef.
(read_stralloc): New declaration.
* target/target.h (target_fileio_read_stralloc): Move it from target.h.
gdb/gdbserver/ChangeLog
2015-07-15 Aleksandar Ristovski <aristovski@qnx.com
Jan Kratochvil <jan.kratochvil@redhat.com>
* target.c: Include target/target-utils.h and fcntl.h.
(target_fileio_read_stralloc_1_pread, target_fileio_read_stralloc_1)
(target_fileio_read_stralloc): New functions.
stdint.h was added to common-defs.h some months ago and should
no longer be included directly by any file.
gdb_assert.h was added to common-defs.h nearly a year ago, but
three includes have crept in since then.
This commit removes all such redundant include directives.
gdb/ChangeLog:
* common/buffer.c (stdint.h): Do not include.
* common/print-utils.c (stdint.h): Likewise.
* compile/compile-c-symbols.c (gdb_assert.h): Likewise.
* compile/compile-c-types.c (gdb_assert.h): Likewise.
* ft32-tdep.c (gdb_assert.h): Likewise.
* guile/scm-utils.c (stdint.h): Likewise.
* i386-linux-tdep.c (stdint.h): Likewise.
* i386-tdep.c (stdint.h): Likewise.
* nat/linux-btrace.c (stdint.h): Likewise.
* nat/linux-btrace.h (stdint.h): Likewise.
* nat/linux-ptrace.c (stdint.h): Likewise.
* nat/mips-linux-watch.h (stdint.h): Likewise.
* ppc-linux-nat.c (stdint.h): Likewise.
* python/python-internal.h (stdint.h): Likewise.
* stub-termcap.c (stdlib.h): Likewise.
* target/target.h (stdint.h): Likewise.
* xtensa-linux-nat.c (stdint.h): Likewise.
gdb/gdbserver/ChangeLog:
* linux-i386-ipa.c (stdint.h): Do not include.
* lynx-i386-low.c (stdint.h): Likewise.
* lynx-ppc-low.c (stdint.h): Likewise.
* mem-break.c (stdint.h): Likewise.
* thread-db.c (stdint.h): Likewise.
* tracepoint.c (stdint.h): Likewise.
* win32-low.c (stdint.h): Likewise.
This commit renames target_stop_ptid as target_stop_and_wait and
target_continue_ptid as target_continue_no_signal. Comments are
updated to more fully describe the functions' behaviour.
gdb/ChangeLog:
* target/target.h (target_stop_ptid): Renamed as...
(target_stop_and_wait): New function. Updated comment.
All uses updated.
(target_continue_ptid): Renamed as...
(target_continue_no_signal): New function. Updated comment.
All uses updated.
This commit makes 19 of the 22 shared .c files in common, nat and
target include common-defs.h instead of defs.h/server.h. The
remaining three files need slight extra work and are dealt with
in separate commits.
gdb/ChangeLog:
* common/agent.c: Include common-defs.h.
Don't include defs.h or server.h.
* common/buffer.c: Likewise.
* common/common-debug.c: Likewise.
* common/common-utils.c: Likewise.
* common/errors.c: Likewise.
* common/filestuff.c: Likewise.
* common/format.c: Likewise.
* common/gdb_vecs.c: Likewise.
* common/print-utils.c: Likewise.
* common/ptid.c: Likewise.
* common/rsp-low.c: Likewise.
* common/signals.c: Likewise.
* common/vec.c: Likewise.
* common/xml-utils.c: Likewise.
* nat/linux-osdata.c: Likewise.
* nat/linux-procfs.c: Likewise.
* nat/linux-ptrace.c: Likewise.
* nat/mips-linux-watch.c: Likewise.
* target/waitstatus.c: Likewise.
This commit introduces two new functions to stop and restart target
processes that shared code can use and that clients must implement.
It also changes some shared code to use these functions.
gdb/ChangeLog:
* target/target.h (target_stop_ptid, target_continue_ptid):
Declare.
* target.c (target_stop_ptid, target_continue_ptid): New
functions.
* common/agent.c [!GDBSERVER]: Don't include infrun.h.
(agent_run_command): Always use target_stop_ptid and
target_continue_ptid.
gdb/gdbserver/ChangeLog:
* target.c (target_stop_ptid, target_continue_ptid): New
functions.
This introduces target/target.h. This file declares some functions
that the shared code can use and that clients must implement. It also
changes some shared code to use these functions.
gdb/ChangeLog:
* target/target.h: New file.
* Makefile.in (HFILES_NO_SRCDIR): Add target/target.h.
* target.h: Include target/target.h.
(target_read_memory, target_write_memory): Don't declare.
* target.c (target_read_uint32): New function.
* common/agent.c: Include target/target.h.
[!GDBSERVER]: Don't include target.h.
(helper_thread_id): Type changed to uint32_t.
(agent_get_helper_thread_id): Use target_read_uint32.
(agent_run_command): Always use target_read_memory and
target_write_memory.
(agent_capability): Type changed to uint32_t.
(agent_capability_check): Use target_read_uint32.
gdb/gdbserver/ChangeLog:
* target.h: Include target/target.h.
* target.c (target_read_memory, target_read_uint32)
(target_write_memory): New functions.
This commit moves the inclusion of common-utils.h to common-defs.h and
removes all other inclusions.
gdb/
2014-08-07 Gary Benson <gbenson@redhat.com>
* common/common-defs.h: Include common-utils.h.
* defs.h: Do not include common-utils.h.
* common/gdb_assert.h: Likewise.
* darwin-nat.h: Likewise.
* nat/linux-btrace.c: Likewise.
* target/waitstatus.h: Likewise.
gdb/gdbserver/
2014-08-07 Gary Benson <gbenson@redhat.com>
* server.h: Do not include common-utils.h.
This commit moves the inclusion of ptid.h to common-defs.h and removes
all other inclusions.
gdb/
2014-08-07 Gary Benson <gbenson@redhat.com>
* common/common-defs.h: Include ptid.h.
* defs.h: Do not include ptid.h.
* inferior.h: Likewise.
* infrun.h: Likewise.
* nat/linux-btrace.h: Likewise.
* nat/linux-osdata.h: Likewise.
* target/waitstatus.h: Likewise.
gdb/gdbserver/
2014-08-07 Gary Benson <gbenson@redhat.com>
* server.h: Do not include ptid.h.
* notif.h: Likewise.
The other day while debugging something related to random signals, I
got confused with "set debug infrun 1" output, for it said:
infrun: TARGET_WAITKIND_STOPPED
infrun: stop_pc = 0x323d4e8b94
infrun: random signal 20
On GNU/Linux, 20 is SIGTSTP. For some reason, it took me a few
minutes to realize that 20 is actually a GDB signal number, not a
target signal number (duh!). In any case, I propose making GDB's
output clearer here:
One way would be to use gdb_signal_to_name, like already used
elsewhere:
infrun: TARGET_WAITKIND_STOPPED
infrun: stop_pc = 0x323d4e8b94
infrun: random signal SIGCHLD (20)
but I think that might confuse someone too ("20? Why does GDB believe
SIGCHLD is 20?"). So I thought of printing the enum string instead:
infrun: TARGET_WAITKIND_STOPPED
infrun: stop_pc = 0x323d4e8b94
infrun: random signal GDB_SIGNAL_CHLD (20)
Looking at a more complete infrun debug log, we had actually printed
the (POSIX) signal name name a bit before:
infrun: target_wait (-1, status) =
infrun: 9300 [Thread 0x7ffff7fcb740 (LWP 9300)],
infrun: status->kind = stopped, signal = SIGCHLD
...
infrun: TARGET_WAITKIND_STOPPED
infrun: stop_pc = 0x323d4e8b94
infrun: random signal 20
So I'm now thinking that it'd be even better to make infrun output
consistently use the enum symbol string, like so:
infrun: clear_proceed_status_thread (Thread 0x7ffff7fca700 (LWP 25663))
infrun: clear_proceed_status_thread (Thread 0x7ffff7fcb740 (LWP 25659))
- infrun: proceed (addr=0xffffffffffffffff, signal=144, step=1)
+ infrun: proceed (addr=0xffffffffffffffff, signal=GDB_SIGNAL_DEFAULT, step=1)
- infrun: resume (step=1, signal=0), trap_expected=0, current thread [Thread 0x7ffff7fcb740 (LWP 25659)] at 0x400700
+ infrun: resume (step=1, signal=GDB_SIGNAL_0), trap_expected=0, current thread [Thread 0x7ffff7fcb740 (LWP 25659)] at 0x400700
infrun: wait_for_inferior ()
infrun: target_wait (-1, status) =
infrun: 25659 [Thread 0x7ffff7fcb740 (LWP 25659)],
- infrun: status->kind = stopped, signal = SIGCHLD
+ infrun: status->kind = stopped, signal = GDB_SIGNAL_CHLD
infrun: infwait_normal_state
infrun: TARGET_WAITKIND_STOPPED
infrun: stop_pc = 0x400700
- infrun: random signal 20
+ infrun: random signal (GDB_SIGNAL_CHLD)
infrun: random signal, keep going
- infrun: resume (step=1, signal=20), trap_expected=0, current thread [Thread 0x7ffff7fcb740 (LWP 25659)] at 0x400700
+ infrun: resume (step=1, signal=GDB_SIGNAL_CHLD), trap_expected=0, current thread [Thread 0x7ffff7fcb740 (LWP 25659)] at 0x400700
infrun: prepare_to_wait
infrun: target_wait (-1, status) =
infrun: 25659 [Thread 0x7ffff7fcb740 (LWP 25659)],
- infrun: status->kind = stopped, signal = SIGTRAP
+ infrun: status->kind = stopped, signal = GDB_SIGNAL_TRAP
infrun: infwait_normal_state
infrun: TARGET_WAITKIND_STOPPED
infrun: stop_pc = 0x400704
infrun: stepi/nexti
infrun: stop_stepping
GDB's signal numbers are public and hardcoded (see
include/gdb/signals.h), so there's really no need to clutter the
output with numeric values in some places while others not. Replacing
the magic "144" with GDB_SIGNAL_DEFAULT in "proceed"'s debug output
(see above) I think is quite nice.
I posit that all this makes it clearer to newcomers that GDB has its
own signal numbering (and that there must be some mapping going on).
Tested on x86_64 Fedora 17.
gdb/
2013-10-23 Pedro Alves <palves@redhat.com>
* common/gdb_signals.h (gdb_signal_to_symbol_string): Declare.
* common/signals.c: Include "gdb_assert.h".
(signals): New field 'symbol'.
(SET): Use the 'symbol' parameter.
(gdb_signal_to_symbol_string): New function.
* infrun.c (handle_inferior_event) <random signal>: In debug
output, print the random signal enum as string in addition to its
number.
* target/waitstatus.c (target_waitstatus_to_string): Print the
signal's enum value as string instead of the (POSIX) signal name.
* Makefile.in (SFILES): Remove common/target-common.c and
add target/waitstatus.c.
(HFILES_NO_SRCDIR): Remove common/target-common.h and add
target/resume.h, target/wait.h and target/waitstatus.h.
(COMMON_OBS): Remove target-common.o and add
waitstatus.o.
(target-common.o): Remove.
(waitstatus.o): New target object file.
* common/target-common.c: Move contents to
target/waitstatus.c and remove.
* common/target-common.h: Move contents to other files and
remove.
(enum resume_kind: Move to target/resume.h.
(TARGET_WNOHANG): Move to target/wait.h.
(enum target_waitkind): Move to target/waitstatus.h.
(struct target_waitstatus): Likewise.
* target.h: Do not include target-common.h and
include target/resume.h, target/wait.h and
target/waitstatus.h.
* target/resume.h: New file.
* target/wait.h: New file.
* target/waitstatus.h: New file.
* target/waitstatus.c: New file.
gdb/gdbserver/
* Makefile.in (INCLUDE_CFLAGS): Include -I$(srcdir)/../.
(SFILES): Remove $(srcdir)/common/target-common.c and
add $(srcdir)/target/waitstatus.c.
(OBS): Remove target-common.o and add waitstatus.o.
(server_h): Remove $(srcdir)/../common/target-common.h and
add $(srcdir)/../target/resume.h, $(srcdir)/../target/wait.h
and $(srcdir)/../target/waitstatus.h.
(target-common.o): Remove.
(waitstatus.o): New target object file.
* target.h: Do not include target-common.h and
include target/resume.h, target/wait.h and
target/waitstatus.h.
Pedro Alves