Add a bit of debug output that made things a bit easier for me before.
gdb/
2015-02-06 Pedro Alves <palves@redhat.com>
* linux-thread-db.c (find_new_threads_callback): Add debug output.
gdb/gdbserver/
2015-02-06 Pedro Alves <palves@redhat.com>
* thread-db.c (find_new_threads_callback): Add debug output.
I wrote a test that attaches to a program that constantly spawns
short-lived threads, which exposed several issues. This is one of
them.
On GNU/Linux, attaching to a multi-threaded program sometimes prints
out warnings like:
...
[New LWP 20700]
warning: unable to open /proc file '/proc/-1/status'
[New LWP 20850]
[New LWP 21019]
...
That happens because when a thread exits, and is joined, glibc does:
nptl/pthread_join.c:
pthread_join ()
{
...
if (__glibc_likely (result == 0))
{
/* We mark the thread as terminated and as joined. */
pd->tid = -1;
...
/* Free the TCB. */
__free_tcb (pd);
}
So if we attach or interrupt the program (which does an implicit "info
threads") at just the right (or rather, wrong) time, we can find and
return threads in the libthread_db/pthreads thread list with kernel
thread ID -1. I've filed glibc PR nptl/17707 for this. You'll find
more info there.
This patch handles this as a special case in GDB.
This is actually more than just a cosmetic issue. lin_lwp_attach_lwp
will think that this -1 is an LWP we're not attached to yet, and after
failing to attach will try to check we were already attached to the
process, using a waitpid call, which in this case ends up being
"waitpid (-1, ...", which obviously results in GDB potentially
discarding an event when it shouldn't...
Tested on x86_64 Fedora 20, native and gdbserver.
gdb/gdbserver/
2015-01-09 Pedro Alves <palves@redhat.com>
* thread-db.c (find_new_threads_callback): Ignore thread if the
kernel thread ID is -1.
gdb/
2015-01-09 Pedro Alves <palves@redhat.com>
* linux-nat.c (lin_lwp_attach_lwp): Assert that the lwp id we're
about to wait for is > 0.
* linux-thread-db.c (find_new_threads_callback): Ignore thread if
the kernel thread ID is -1.
... instead of relying on libthread_db.
I wrote a test that attaches to a program that constantly spawns
short-lived threads, which exposed several issues. This is one of
them.
On Linux, we need to attach to all threads of a process (thread group)
individually. We currently rely on libthread_db to list the threads,
but that is problematic, because libthread_db relies on reading data
structures out of the inferior (which may well be corrupted). If
threads are being created or exiting just while we try to attach, we
may trip on inconsistencies in the inferior's thread list. To work
around that, when we see a seemingly corrupt list, we currently retry
a few times:
static void
thread_db_find_new_threads_2 (ptid_t ptid, int until_no_new)
{
...
if (until_no_new)
{
/* Require 4 successive iterations which do not find any new threads.
The 4 is a heuristic: there is an inherent race here, and I have
seen that 2 iterations in a row are not always sufficient to
"capture" all threads. */
...
That heuristic may well fail, and when it does, we end up with threads
in the program that aren't under GDB's control. That's obviously bad
and results in quite mistifying failures, like e.g., the process dying
for seeminly no reason when a thread that wasn't attached trips on a
breakpoint.
There's really no reason to rely on libthread_db for this nowadays
when we have /proc mounted. In that case, which is the usual case, we
can list the LWPs from /proc/PID/task/. In fact, GDBserver is already
doing this. The patch factors out that code that knows to walk the
task/ directory out of GDBserver, and makes GDB use it too.
Like GDBserver, the patch makes GDB attach to LWPs and _not_ wait for
them to stop immediately. Instead, we just tag the LWP as having an
expected stop. Because we can only set the ptrace options when the
thread stops, we need a new flag in the lwp structure to keep track of
whether we've already set the ptrace options, just like in GDBserver.
Note that nothing issues any ptrace command to the threads between the
PTRACE_ATTACH and the stop, so this is safe (unlike one scenario
described in gdbserver's linux-low.c).
When we attach to a program that has threads exiting while we attach,
it's easy to race with a thread just exiting as we try to attach to
it, like:
#1 - get current list of threads
#2 - attach to each listed thread
#3 - ooops, attach failed, thread is already gone
As this is pretty normal, we shouldn't be issuing a scary warning in
step #3.
When #3 happens, PTRACE_ATTACH usually fails with ESRCH, but sometimes
we'll see EPERM as well. That happens when the kernel still has the
thread in its task list, but the thread is marked as dead.
Unfortunately, EPERM is ambiguous and we'll get it also on other
scenarios where the thread isn't dead, and in those cases, it's useful
to get a warning. To distiguish the cases, when we get an EPERM
failure, we open /proc/PID/status, and check the thread's state -- if
the /proc file no longer exists, or the state is "Z (Zombie)" or "X
(Dead)", we ignore the EPERM error silently; otherwise, we'll warn.
Unfortunately, there seems to be a kernel race here. Sometimes I get
EPERM, and then the /proc state still indicates "R (Running)"... If
we wait a bit and retry, we do end up seeing X or Z state, or get an
ESRCH. I thought of making GDB retry the attach a few times, but even
with a 500ms wait and 4 retries, I still see the warning sometimes. I
haven't been able to identify the kernel path that causes this yet,
but in any case, it looks like a kernel bug to me. As this just
results failure to suppress a warning that we've been printing since
about forever anyway, I'm just making the test cope with it, and issue
an XFAIL.
gdb/gdbserver/
2015-01-09 Pedro Alves <palves@redhat.com>
* linux-low.c (linux_attach_fail_reason_string): Move to
nat/linux-ptrace.c, and rename.
(linux_attach_lwp): Update comment.
(attach_proc_task_lwp_callback): New function.
(linux_attach): Adjust to rename and use
linux_proc_attach_tgid_threads.
(linux_attach_fail_reason_string): Delete declaration.
gdb/
2015-01-09 Pedro Alves <palves@redhat.com>
* linux-nat.c (attach_proc_task_lwp_callback): New function.
(linux_nat_attach): Use linux_proc_attach_tgid_threads.
(wait_lwp, linux_nat_filter_event): If not set yet, set the lwp's
ptrace option flags.
* linux-nat.h (struct lwp_info) <must_set_ptrace_flags>: New
field.
* nat/linux-procfs.c: Include <dirent.h>.
(linux_proc_get_int): New parameter "warn". Handle it.
(linux_proc_get_tgid): Adjust.
(linux_proc_get_tracerpid): Rename to ...
(linux_proc_get_tracerpid_nowarn): ... this.
(linux_proc_pid_get_state): New function, factored out from
(linux_proc_pid_has_state): ... this. Add new parameter "warn"
and handle it.
(linux_proc_pid_is_gone): New function.
(linux_proc_pid_is_stopped): Adjust.
(linux_proc_pid_is_zombie_maybe_warn)
(linux_proc_pid_is_zombie_nowarn): New functions.
(linux_proc_pid_is_zombie): Use
linux_proc_pid_is_zombie_maybe_warn.
(linux_proc_attach_tgid_threads): New function.
* nat/linux-procfs.h (linux_proc_get_tgid): Update comment.
(linux_proc_get_tracerpid): Rename to ...
(linux_proc_get_tracerpid_nowarn): ... this, and update comment.
(linux_proc_pid_is_gone): New declaration.
(linux_proc_pid_is_zombie): Update comment.
(linux_proc_pid_is_zombie_nowarn): New declaration.
(linux_proc_attach_lwp_func): New typedef.
(linux_proc_attach_tgid_threads): New declaration.
* nat/linux-ptrace.c (linux_ptrace_attach_fail_reason): Adjust to
use nowarn functions.
(linux_ptrace_attach_fail_reason_string): Move here from
gdbserver/linux-low.c and rename.
(ptrace_supports_feature): If the current ptrace options are not
known yet, check them now, instead of asserting.
* nat/linux-ptrace.h (linux_ptrace_attach_fail_reason_string):
Declare.
GDB has a function named "current_inferior" and gdbserver has a global
variable named "current_inferior", but the two are not equivalent;
indeed, gdbserver does not have any real equivalent of what GDB calls
an inferior. What gdbserver's "current_inferior" is actually pointing
to is a structure describing the current thread. This commit renames
current_inferior as current_thread in gdbserver to clarify this. It
also renames the function "set_desired_inferior" to "set_desired_thread"
and renames various local variables from foo_inferior to foo_thread.
gdb/gdbserver/ChangeLog:
* inferiors.h (current_inferior): Renamed as...
(current_thread): New variable. All uses updated.
* linux-low.c (get_pc): Renamed saved_inferior as saved_thread.
(maybe_move_out_of_jump_pad): Likewise.
(cancel_breakpoint): Likewise.
(linux_low_filter_event): Likewise.
(wait_for_sigstop): Likewise.
(linux_resume_one_lwp): Likewise.
(need_step_over_p): Likewise.
(start_step_over): Likewise.
(linux_stabilize_threads): Renamed save_inferior as saved_thread.
* linux-x86-low.c (x86_linux_update_xmltarget): Likewise.
* proc-service.c (ps_lgetregs): Renamed reg_inferior as reg_thread
and save_inferior as saved_thread.
* regcache.c (get_thread_regcache): Renamed saved_inferior as
saved_thread.
(regcache_invalidate_thread): Likewise.
* remote-utils.c (prepare_resume_reply): Likewise.
* thread-db.c (thread_db_get_tls_address): Likewise.
(disable_thread_event_reporting): Likewise.
(remove_thread_event_breakpoints): Likewise.
* tracepoint.c (gdb_agent_about_to_close): Renamed save_inferior
as saved_thread.
* target.h (set_desired_inferior): Renamed as...
(set_desired_thread): New declaration. All uses updated.
* server.c (myresume): Updated comment to reference thread instead
of inferior.
(handle_serial_event): Likewise.
(handle_target_event): Likewise.
I have posted:
TLS variables access for -static -lpthread executables
https://sourceware.org/ml/libc-help/2014-03/msg00024.html
and the GDB patch below has been confirmed as OK for current glibcs.
Further work should be done for newer glibcs:
Improve TLS variables glibc compatibility
https://sourceware.org/bugzilla/show_bug.cgi?id=16954
Still the patch below implements the feature in a fully functional way backward
compatible with current glibcs, it depends on the following glibc source line:
csu/libc-tls.c
main_map->l_tls_modid = 1;
gdb/
2014-05-21 Jan Kratochvil <jan.kratochvil@redhat.com>
Fix TLS access for -static -pthread.
* linux-thread-db.c (struct thread_db_info): Add td_thr_tlsbase_p.
(try_thread_db_load_1): Initialize it.
(thread_db_get_thread_local_address): Call it if LM is zero.
* target.c (target_translate_tls_address): Remove LM_ADDR zero check.
* target.h (struct target_ops) (to_get_thread_local_address): Add
load_module_addr comment.
gdb/gdbserver/
2014-05-21 Jan Kratochvil <jan.kratochvil@redhat.com>
Fix TLS access for -static -pthread.
* gdbserver/thread-db.c (struct thread_db): Add td_thr_tlsbase_p.
(thread_db_get_tls_address): Call it if LOAD_MODULE is zero.
(thread_db_load_search, try_thread_db_load_1): Initialize it.
gdb/testsuite/
2014-05-21 Jan Kratochvil <jan.kratochvil@redhat.com>
Fix TLS access for -static -pthread.
* gdb.threads/staticthreads.c <HAVE_TLS> (tlsvar): New.
<HAVE_TLS> (thread_function, main): Initialize it.
* gdb.threads/staticthreads.exp: Try gdb_compile_pthreads for $have_tls.
Add clean_restart.
<$have_tls != "">: Check TLSVAR.
Message-ID: <20140410115204.GB16411@host2.jankratochvil.net>
On Linux, we need to explicitly ptrace attach to all lwps of a
process. Because GDB might not be connected yet when an attach is
requested, and thus it may not be possible to activate thread_db, as
that requires access to symbols (IOW, gdbserver --attach), a while ago
we make linux_attach loop over the lwps as listed by /proc/PID/task to
find the lwps to attach to.
linux_attach_lwp_1 has:
...
if (initial)
/* If lwp is the tgid, we handle adding existing threads later.
Otherwise we just add lwp without bothering about any other
threads. */
ptid = ptid_build (lwpid, lwpid, 0);
else
{
/* Note that extracting the pid from the current inferior is
safe, since we're always called in the context of the same
process as this new thread. */
int pid = pid_of (current_inferior);
ptid = ptid_build (pid, lwpid, 0);
}
That "safe" comment referred to linux_attach_lwp being called by
thread-db.c. But this was clearly missed when a new call to
linux_attach_lwp_1 was added to linux_attach. As a result,
current_inferior will be set to some random process, and non-initial
lwps of the second inferior get assigned the pid of the wrong
inferior. E.g., in the case of attaching to two inferiors, for the
second inferior (and so on), non-initial lwps of the second inferior
get assigned the pid of the first inferior. This doesn't trigger on
the first inferior, when current_inferior is NULL, add_thread switches
the current inferior to the newly added thread.
Rather than making linux_attach switch current_inferior temporarily
(thus avoiding further reliance on global state), or making
linux_attach_lwp_1 get the tgid from /proc, which add extra syscalls,
and will be wrong in case of the user having originally attached
directly to a non-tgid lwp, and then that lwp spawning new clones (the
ptid.pid field of further new clones should be the same as the
original lwp's pid, which is not the tgid), we note that callers of
linux_attach_lwp/linux_attach_lwp_1 always have the right pid handy
already, so they can pass it down along with the lwpid.
The only other reason for the "initial" parameter is to error out
instead of warn in case of attach failure, when we're first attaching
to a process. There are only three callers of
linux_attach_lwp/linux_attach_lwp_1, and each wants to print a
different warn/error string, so we can just move the error/warn out of
linux_attach_lwp_1 to the callers, thus getting rid of the "initial"
parameter.
There really nothing gdbserver-specific about attaching to two
threaded processes, so this adds a new test under gdb.multi/. The
test passes cleanly against the native GNU/Linux target, but
fails/triggers the bug against GDBserver (before the patch), with the
native-extended-remote board (as plain remote doesn't support
multi-process).
Tested on x86_64 Fedora 17, with the native-extended-gdbserver board.
gdb/gdbserver/
2014-04-25 Pedro Alves <palves@redhat.com>
PR server/16255
* linux-low.c (linux_attach_fail_reason_string): New function.
(linux_attach_lwp): Delete.
(linux_attach_lwp_1): Rename to ...
(linux_attach_lwp): ... this. Take a ptid instead of a pid as
argument. Remove "initial" parameter. Return int instead of
void. Don't error or warn here.
(linux_attach): Adjust to call linux_attach_lwp. Call error on
failure to attach to the tgid. Call warning when failing to
attach to an lwp.
* linux-low.h (linux_attach_lwp): Take a ptid instead of a pid as
argument. Remove "initial" parameter. Return int instead of
void. Don't error or warn here.
(linux_attach_fail_reason_string): New declaration.
* thread-db.c (attach_thread): Adjust to linux_attach_lwp's
interface change. Use linux_attach_fail_reason_string.
gdb/
2014-04-25 Pedro Alves <palves@redhat.com>
PR server/16255
* common/linux-ptrace.c (linux_ptrace_attach_warnings): Rename to ...
(linux_ptrace_attach_fail_reason): ... this. Remove "warning: "
and newline from built string.
* common/linux-ptrace.h (linux_ptrace_attach_warnings): Rename to ...
(linux_ptrace_attach_fail_reason): ... this.
* linux-nat.c (linux_nat_attach): Adjust to use
linux_ptrace_attach_fail_reason.
gdb/testsuite/
2014-04-25 Simon Marchi <simon.marchi@ericsson.com>
Pedro Alves <palves@redhat.com>
PR server/16255
* gdb.multi/multi-attach.c: New file.
* gdb.multi/multi-attach.exp: New file.
null ptr check to prevent gdbserver from crashing
Evaluating a thread local storage variable in a remote scenario crashes
gdbserver if libthread-db could not be loaded.
2013-02-12 Sanimir Agovic <sanimir.agovic@intel.com>
gdbserver/
* thread-db.c (thread_db_get_tls_address):
NULL pointer check thread_db.
testsuite/
* gdb.server/no-thread-db.exp: New file.
* gdb.server/no-thread-db.c: New file.
* gdb.server/Makefile.in (EXECUTABLES): Add no-thread-db.
Two modifications:
1. The addition of 2013 to the copyright year range for every file;
2. The use of a single year range, instead of potentially multiple
year ranges, as approved by the FSF.
* common/gdb_string.h: ... here.
* common/vec.h: Remove #ifndef GDBSERVER conditional inclusion of
gdb_string.h and gdb_assert.h.
gdbserver/
* configure.ac: Add check for strstr.
* config.in: Regenerate.
* configure: Regenerate.
* linux-thread-db.c: #include "gdb_vecs.h".
(try_thread_db_load_from_pdir_1): New arg "subdir". All callers
updated.
(try_thread_db_load_from_pdir): New arg "subdir". All callers updated.
(thread_db_load_search): Use a vector to iterate over path elements.
Handle text appearing after "$pdir".
gdbserver/
* Makefile.in (SFILES): Add gdb_vecs.c.
(OBS): Add gdb_vecs.o.
(gdb_vecs_h, host_defs_h): New variables.
(thread-db.o): Add $(gdb_vecs_h) dependency.
(gdb_vecs.o): New rule.
* thread-db.c: #include "gdb_vecs.h".
(thread_db_load_search): Use a vector to iterate over path elements.
Handle text appearing after "$pdir".
* NEWS: Mention $sdir,$pdir.
* gdb_thread_db.h (LIBTHREAD_DB_SEARCH_PATH): Add $sdir:$pdir.
* linux-thread-db.c (try_thread_db_load_from_pdir): New function.
(try_thread_db_load_from_sdir): New function.
(try_thread_db_load_from_dir): New function.
(thread_db_load_search): Handle $pdir, $sdir. Remove trying of
system directories if search of libthread-db-search-path fails,
that is now done via $sdir.
(has_libpthread): New function.
(thread_db_load): Remove search for libthread_db in directory of
libpthread, that is now done via $pdir.
gdbserver/
* thread-db.c (try_thread_db_load_from_sdir): New function.
(try_thread_db_load_from_dir): New function.
(thread_db_load_search): Handle $sdir, ignore $pdir.
Remove trying of system directories if search of
libthread-db-search-path fails, that is now done via $sdir.
doc/
* gdb.texinfo (Threads): Document $sdir,$pdir.
(Server): Document $pdir exception.
(_initialize_thread_db): Add setter for libthread-db-search-path.
gdbserver/
* thread-db.c (thread_db_handle_monitor_command): Handle elided path.
doc/
* gdb.texinfo (Threads): If an empty path is provided for
libthread-db-search-path it is reset to its default value.
(Server): Ditto.
snprintf is not available on LynxOS, so I changed the calls to snprintf
to calls to xsnprintf, which should be strictly equivalent.
gdb/gdbserver/ChangeLog:
* utils.c (xsnprintf): Make non-static.
* server.h: Add xsnprintf declaration.
* linux-low.c, nto-low.c, target.c, thread-db.c, tracepoint.c:
replace calls to snprintf by calls to xsnprintf throughout.
* proc-service.c (ps_pglobal_lookup): Use
thread_db_look_up_one_symbol.
* remote-utils.c (look_up_one_symbol): Add new `may_ask_gdb'
parameter. Use it instead of all_symbols_looked_up.
* server.h (struct process_info) <all_symbols_looked_up>: Delete
field.
(all_symbols_looked_up): Don't declare.
(look_up_one_symbol): Add new `may_ask_gdb' parameter.
* thread-db.c (struct thread_db) <all_symbols_looked_up>: New
field.
(thread_db_look_up_symbols): Adjust call to look_up_one_symbol.
Set all_symbols_looked_up here.
(thread_db_look_up_one_symbol): New.
(thread_db_get_tls_address): Adjust.
(thread_db_load_search, try_thread_db_load_1): Always allocate the
thread_db object on the heap, and tentatively set it in the
process structure.
(thread_db_init): Don't set all_symbols_looked_up here.
* linux-low.h (thread_db_look_up_one_symbol): Declare.
(linux_kill): Stop all lwps here. Don't delete the main lwp here.
(linux_detach_one_lwp): Assume the lwp is stopped.
(any_thread_of): Delete.
(linux_detach): Stop all lwps here. Don't blindly delete all
breakpoints.
(delete_lwp_callback): New.
(linux_mourn): Delete all lwps of the process that is gone.
(linux_wait_1): Don't delete the last lwp of the process here.
* mem-break.h (mark_breakpoints_out): Declare.
* mem-break.c (mark_breakpoints_out): New.
(free_all_breakpoints): Use it.
* server.c (handle_target_event): If the process is gone, mark
breakpoints out.
* thread-db.c (struct thread_db) <create_bp>: New field.
(thread_db_enable_reporting): Fix prototype. Store a thread event
breakpoint reference in the thread_db struct.
(thread_db_load_search): Clear the thread_db object.
(try_thread_db_load_1): Ditto.
(switch_to_process): New.
(disable_thread_event_reporting): Use it.
(remove_thread_event_breakpoints): New.
(thread_db_detach, thread_db_mourn): Use it.
* linux-low.c (linux_remove_process): Delete.
(add_lwp): Don't set last_resume_kind here.
(linux_kill): Use `mourn'.
(linux_detach): Use `thread_db_detach', and `mourn'.
(linux_mourn): New.
(linux_attach_lwp_1): Adjust comment.
(linux_attach): last_resume_kind moved the thread_info; adjust.
(status_pending_p_callback): Adjust.
(linux_wait_for_event_1): Adjust.
(count_events_callback, select_singlestep_lwp_callback)
(select_event_lwp_callback, cancel_breakpoints_callback)
(db_wants_lwp_stopped, linux_wait_1, need_step_over_p)
(proceed_one_lwp): Adjust.
(linux_async): Add debug output.
(linux_thread_stopped): New.
(linux_pause_all): New.
(linux_target_ops): Install linux_mourn, linux_thread_stopped and
linux_pause_all.
* linux-low.h (struct lwp_info): Delete last_resume_kind field.
(thread_db_free): Delete declaration.
(thread_db_detach, thread_db_mourn): Declare.
* thread-db.c (thread_db_init): Use thread_db_mourn.
(thread_db_free): Delete, split in two.
(disable_thread_event_reporting): New.
(thread_db_detach): New.
(thread_db_mourn): New.
* server.h (struct thread_info) <last_resume_kind>: New field.
<attached>: Add comment.
<gdb_detached>: New field.
(handler_func): Change return type to int.
(handle_serial_event, handle_target_event): Ditto.
(gdb_connected): Declare.
(tracing): Delete.
(disconnected_tracing): Declare.
(stop_tracing): Declare.
* server.c (handle_query) <qSupported>: Report support for
disconnected tracing.
(queue_stop_reply_callback): Account for running threads.
(gdb_wants_thread_stopped): New.
(gdb_wants_all_threads_stopped): New.
(gdb_reattached_process): New.
(handle_status): Clear the `gdb_detached' flag of all processes.
In all-stop, stop all threads.
(main): Be sure to leave tfind mode. Handle disconnected tracing.
(process_serial_event): If the remote connection breaks, or if an
exit was forced with "monitor exit", force an event loop exit.
Handle disconnected tracing on detach.
(handle_serial_event): Adjust.
(handle_target_event): If GDB isn't connected, forward events back
to the inferior, unless the last process exited, in which case,
exit gdbserver. Adjust interface.
* remote-utils.c (remote_open): Don't block in accept. Instead
register an event loop source on the listen socket file
descriptor. Refactor bits into ...
(listen_desc): ... this new global.
(gdb_connected): ... this new function.
(enable_async_notification): ... this new function.
(handle_accept_event): ... this new function.
(remote_close): Clear remote_desc.
* inferiors.c (add_thread): Set the new thread's last_resume_kind.
* target.h (struct target_ops) <mourn, thread_stopped, pause_all>:
New fields.
(mourn_inferior): Define.
(target_process_qsupported): Avoid the dangling else problem.
(thread_stopped): Define.
(pause_all): Define.
(target_waitstatus_to_string): Declare.
* target.c (target_waitstatus_to_string): New.
* tracepoint.c (tracing): Make extern.
(disconnected_tracing): New.
(stop_tracing): Make extern. Handle tracing stops due to GDB
disconnecting.
(cmd_qtdisconnected): New.
(cmd_qtstatus): Report disconnected tracing status in trace reply.
(handle_tracepoint_general_set): Handle QTDisconnected.
* event-loop.c (event_handler_func): Change return type to int.
(process_event): Bail out if the event handler wants the event
loop to stop.
(handle_file_event): Ditto.
(start_event_loop): Bail out if the event handler wants the event
loop to stop.
* nto-low.c (nto_target_ops): Adjust.
* spu-low.c (spu_wait): Don't remove the process here.
(spu_target_ops): Adjust.
* win32-low.c (win32_wait): Don't remove the process here.
(win32_target_ops): Adjust.
parameter. Don't release/detach from thread_db here.
(linux_kill): Release/detach from thread_db here, ...
(linux_detach): ... and here, before actually detaching.
(linux_wait_1): ... and here, when a process exits.
* thread-db.c (any_thread_of): New.
(thread_db_free): Switch the current inferior to a thread of the
passed in process.
* gdb_proc_service.h (psaddr_t): Fix type.
* linux-thread-db.c (thread_db_info.td_thr_tls_get_addr_p): Fix
signature to match glibc.
(thread_db_get_thread_local_address): Use psaddr_t for type of
address to match parameter of td_thr_tls_get_addr_p.
Cast through psaddr_t instead of (void*) to match parameter of
td_thr_tls_get_addr_p.
gdbserver/
* gdb_proc_service.h (psaddr_t): Fix type.
* thread-db.c (thread_db_info.td_thr_tls_get_addr_p): Fix
signature to match glibc.
Pass it to thread_db_free.
(linux_kill, linux_detach, linux_wait_1): Adjust to pass the
proper `detaching' argument to linux_remove_process.
* linux-low.h (thread_db_free): Add `detaching' parameter.
* thread-db.c (thread_db_init): Pass false as `detaching' argument
to thread_db_free.
(thread_db_free): Add `detaching' parameter. Only
call td_ta_clear_event if detaching from process.
PR gdb/10757
* thread-db.c (attach_thread): New function.
(maybe_attach_thread): Return success/failure.
(find_new_threads_callback): Adjust.
(thread_db_find_new_threads): Loop until no new threads.
* server.h (get_thread_process): Add prototype.
* thread-db.c (find_one_thread): Use get_thread_process
instead of current_process.
(thread_db_get_tls_address): Do not crash if called when
thread layer is not yet initialized.
Implement the multiprocess extensions, and add linux multiprocess
support.
* server.h (ULONGEST): Declare.
(struct ptid, ptid_t): New.
(minus_one_ptid, null_ptid): Declare.
(ptid_build, pid_to_ptid, ptid_get_pid, ptid_get_lwp)
(ptid_get_tid, ptid_equal, ptid_is_pid): Declare.
(struct inferior_list_entry): Change `id' type from unsigned from
to ptid_t.
(struct sym_cache, struct breakpoint, struct
process_info_private): Forward declare.
(struct process_info): Declare.
(current_process): Declare.
(all_processes): Declare.
(initialize_inferiors): Declare.
(add_thread): Adjust to use ptid_t.
(thread_id_to_gdb_id, thread_to_gdb_id, gdb_id_to_thread_id): Ditto.
(add_process, remove_process, find_thread_pid): Declare.
(find_inferior_id): Adjust to use ptid_t.
(cont_thread, general_thread, step_thread): Change type to ptid_t.
(multi_process): Declare.
(push_event): Adjust to use ptid_t.
(read_ptid, write_ptid): Declare.
(prepare_resume_reply): Adjust to use ptid_t.
(clear_symbol_cache): Declare.
* inferiors.c (all_processes): New.
(null_ptid, minus_one_ptid): New.
(ptid_build, pid_to_ptid, ptid_get_pid, ptid_get_lwp)
(ptid_get_tid, ptid_equal, ptid_is_pid): New.
(add_thread): Change unsigned long to ptid. Remove gdb_id
parameter. Adjust.
(thread_id_to_gdb_id, thread_to_gdb_id): Change unsigned long to ptid.
(gdb_id_to_thread): Rename to ...
(find_thread_pid): ... this. Change unsigned long to ptid.
(gdb_id_to_thread_id, find_inferior_id): Change unsigned long to ptid.
(loaded_dll, pull_pid_from_list): Adjust.
(add_process, remove_process, find_process_pid)
(get_thread_process, current_process, initialize_inferiors): New.
* target.h (struct thread_resume) <thread>: Change type to ptid_t.
(struct target_waitstatus) <related_pid>: Ditto.
(struct target_ops) <kill, detach>: Add `pid' argument. Change
return type to int.
(struct target_ops) <join>: Add `pid' argument.
(struct target_ops) <thread_alive>: Change pid's type to ptid_t.
(struct target_ops) <wait>: Add `ptid' field. Change return type
to ptid.
(kill_inferior, detach_inferior, join_inferior): Add `pid' argument.
(mywait): Add `ptid' argument. Change return type to ptid_t.
(target_pid_to_str): Declare.
* target.c (set_desired_inferior): Adjust to use ptids.
(mywait): Add new `ptid' argument. Adjust.
(target_pid_to_str): New.
* mem-break.h (free_all_breakpoints): Declare.
* mem-break.c (breakpoints): Delelete.
(set_breakpoint_at, delete_breakpoint, find_breakpoint_at)
(check_mem_read, check_mem_write, delete_all_breakpoints): Adjust
to use per-process breakpoint list.
(free_all_breakpoints): New.
* remote-utils.c (struct sym_cache) <name>: Drop `const'.
(symbol_cache, all_symbols_looked_up): Delete.
(hexchars): New.
(ishex, unpack_varlen_hex, write_ptid, hex_or_minus_one,
read_ptid): New.
(prepare_resume_reply): Change ptid argument's type from unsigned
long to ptid_t. Adjust. Implement W;process and X;process.
(free_sym_cache, clear_symbol_cache): New.
(look_up_one_symbol): Adjust to per-process symbol cache. *
* server.c (cont_thread, general_thread, step_thread): Change type
to ptid_t.
(attached): Delete.
(multi_process): New.
(last_ptid): Change type to ptid_t.
(struct vstop_notif) <ptid>: Change type to ptid_t.
(queue_stop_reply, push_event): Change `ptid' argument's type to
ptid_t.
(discard_queued_stop_replies): Add `pid' argument.
(start_inferior): Adjust to use ptids. Adjust to mywait interface
changes. Don't reference the `attached' global.
(attach_inferior): Adjust to mywait interface changes.
(handle_query): Adjust to use ptids. Parse GDB's qSupported
features. Handle and report "multiprocess+". Handle
"qAttached:PID".
(handle_v_cont): Adjust to use ptids. Adjust to mywait interface
changes.
(handle_v_kill): New.
(handle_v_stopped): Adjust to use target_pid_to_str.
(handle_v_requests): Allow multiple attaches and runs when
multiprocess extensions are in effect. Handle "vKill".
(myresume): Adjust to use ptids.
(queue_stop_reply_callback): Add `arg' parameter. Handle it.
(handle_status): Adjust to discard_queued_stop_replies interface
change.
(first_thread_of, kill_inferior_callback)
(detach_or_kill_inferior_callback, join_inferiors_callback): New.
(main): Call initialize_inferiors. Adjust to use ptids, killing
and detaching from all inferiors. Handle multiprocess packet
variants.
* linux-low.h: Include gdb_proc_service.h.
(struct process_info_private): New.
(struct linux_target_ops) <pid_of>: Use ptid_get_pid.
<lwpid_of>: Use ptid_get_lwp.
(get_lwp_thread): Adjust.
(struct lwp_info): Add `dead' member.
(find_lwp_pid): Declare.
* linux-low.c (thread_db_active): Delete.
(new_inferior): Adjust comment.
(inferior_pid): Delete.
(linux_add_process): New.
(handle_extended_wait): Adjust.
(add_lwp): Change unsigned long to ptid.
(linux_create_inferior): Add process to processes table. Adjust
to use ptids. Don't set new_inferior here.
(linux_attach_lwp): Rename to ...
(linux_attach_lwp_1): ... this. Add `initial' argument. Handle
it. Adjust to use ptids.
(linux_attach_lwp): New.
(linux_attach): Add process to processes table. Don't set
new_inferior here.
(struct counter): New.
(second_thread_of_pid_p, last_thread_of_process_p): New.
(linux_kill_one_lwp): Add `args' parameter. Handle it. Adjust to
multiple processes.
(linux_kill): Add `pid' argument. Handle it. Adjust to multiple
processes. Remove process from process table.
(linux_detach_one_lwp): Add `args' parameter. Handle it. Adjust
to multiple processes.
(any_thread_of): New.
(linux_detach): Add `pid' argument, and handle it. Remove process
from processes table.
(linux_join): Add `pid' argument. Handle it.
(linux_thread_alive): Change unsighed long argument to ptid_t.
Consider dead lwps as not being alive.
(status_pending_p): Rename `dummy' argument to `arg'. Filter out
threads we're not interested in.
(same_lwp, find_lwp_pid): New.
(linux_wait_for_lwp): Change `pid' argument's type from int to
ptid_t. Adjust.
(linux_wait_for_event): Rename to ...
(linux_wait_for_event_1): ... this. Change `pid' argument's type
from int to ptid_t. Adjust.
(linux_wait_for_event): New.
(linux_wait_1): Add `ptid' argument. Change return type to
ptid_t. Adjust. Use last_thread_of_process_p. Remove processes
that exit from the process table.
(linux_wait): Add `ptid' argument. Change return type to ptid_t.
Adjust.
(mark_lwp_dead): New.
(wait_for_sigstop): Adjust to use ptids. If a process exits while
stopping all threads, mark its main lwp as dead.
(linux_set_resume_request, linux_resume_one_thread): Adjust to use
ptids.
(fetch_register, usr_store_inferior_registers)
(regsets_fetch_inferior_registers)
(regsets_store_inferior_registers, linux_read_memory)
(linux_write_memory): Inline `inferior_pid'.
(linux_look_up_symbols): Adjust to use per-process
`thread_db_active'.
(linux_request_interrupt): Adjust to use ptids.
(linux_read_auxv): Inline `inferior_pid'.
(initialize_low): Don't reference thread_db_active.
* gdb_proc_service.h (struct ps_prochandle) <pid>: Remove.
* proc-service.c (ps_lgetregs): Use find_lwp_pid.
(ps_getpid): Return the pid of the current inferior.
* thread-db.c (proc_handle, thread_agent): Delete.
(thread_db_create_event, thread_db_enable_reporting): Adjust to
per-process data.
(find_one_thread): Change argument type to ptid_t. Adjust to
per-process data.
(maybe_attach_thread): Adjust to per-process data and ptids.
(thread_db_find_new_threads): Ditto.
(thread_db_init): Ditto.
* spu-low.c (spu_create_inferior, spu_attach): Add process to
processes table. Adjust to use ptids.
(spu_kill, spu_detach): Adjust interface. Remove process from
processes table.
(spu_join, spu_thread_alive): Adjust interface.
(spu_wait): Adjust interface. Remove process from processes
table. Adjust to use ptids.
* win32-low.c (current_inferior_tid): Delete.
(current_inferior_ptid): New.
(debug_event_ptid): New.
(thread_rec): Take a ptid. Adjust.
(child_add_thread): Add `pid' argument. Adjust to use ptids.
(child_delete_thread): Ditto.
(do_initial_child_stuff): Add `attached' argument. Add process to
processes table.
(child_fetch_inferior_registers, child_store_inferior_registers):
Adjust.
(win32_create_inferior): Pass 0 to do_initial_child_stuff.
(win32_attach): Pass 1 to do_initial_child_stuff.
(win32_kill): Adjust interface. Remove process from processes
table.
(win32_detach): Ditto.
(win32_join): Adjust interface.
(win32_thread_alive): Take a ptid.
(win32_resume): Adjust to use ptids.
(get_child_debug_event): Ditto.
(win32_wait): Adjust interface. Remove exiting process from
processes table.
* server.h (non_stop): Declare.
(gdb_client_data, handler_func): Declare.
(delete_file_handler, add_file_handler, start_event_loop):
Declare.
(handle_serial_event, handle_target_event, push_event)
(putpkt_notif): Declare.
* target.h (enum resume_kind): New.
(struct thread_resume): Replace `step' field by `kind' field.
(TARGET_WNOHANG): Define.
(struct target_ops) <wait>: Add `options' argument.
<supports_non_stop, async, start_non_stop>: New fields.
(target_supports_non_stop, target_async): New.
(start_non_stop): Declare.
(mywait): Add `options' argument.
* target.c (mywait): Add `options' argument. Print child exit
notifications here.
(start_non_stop): New.
* server.c (non_stop, own_buf, mem_buf): New globals.
(struct vstop_notif): New.
(notif_queue): New global.
(queue_stop_reply, push_event, discard_queued_stop_replies)
(send_next_stop_reply): New.
(start_inferior): Adjust to use resume_kind. Adjust to mywait
interface changes.
(attach_inferior): In non-stop mode, don't wait for the target
here.
(handle_general_set): Handle QNonStop.
(handle_query): When handling qC, return the current general
thread, instead of the first thread of the list.
(handle_query): If the backend supports non-stop mode, include
QNonStop+ in the qSupported query response.
(handle_v_cont): Adjust to use resume_kind. Handle resume_stop
and non-stop mode.
(handle_v_attach, handle_v_run): Handle non-stop mode.
(handle_v_stopped): New.
(handle_v_requests): Report support for vCont;t. Handle vStopped.
(myresume): Adjust to use resume_kind. Handle non-stop.
(queue_stop_reply_callback): New.
(handle_status): Handle non-stop mode.
(main): Clear non_stop flag on reconnection. Use the event-loop.
Refactor serial protocol handling from here ...
(process_serial_event): ... to this new function. When GDB
selects any thread, select one here. In non-stop mode, wait until
GDB acks all pending events before exiting.
(handle_serial_event, handle_target_event): New.
* remote-utils.c (remote_open): Install remote_desc in the event
loop.
(remote_close): Remove remote_desc from the event loop.
(putpkt_binary): Rename to...
(putpkt_binary_1): ... this. Add `is_notic' argument. Handle it.
(putpkt_binary): New as wrapper around putpkt_binary_1.
(putpkt_notif): New.
(prepare_resume_reply): In non-stop mode, don't change the
general_thread.
* event-loop.c: New.
* Makefile.in (OBJ): Add event-loop.o.
(event-loop.o): New rule.
* linux-low.h (pid_of): Moved here.
(lwpid_of): New.
(get_lwp_thread): Use lwpid_of.
(struct lwp_info): Delete `lwpid' field. Add `suspended' field.
* linux-low.c (pid_of): Delete.
(inferior_pid): Use lwpid_of.
(linux_event_pipe): New.
(target_is_async_p): New.
(delete_lwp): New.
(handle_extended_wait): Use lwpid_of.
(add_lwp): Don't set lwpid field.
(linux_attach_lwp): Adjust debug output. Use lwpid_of.
(linux_kill_one_lwp): If killing a running lwp, stop it first.
Use lwpid_of. Adjust to linux_wait_for_event interface changes.
(linux_detach_one_lwp): If detaching from a running lwp, stop it
first. Adjust to linux_wait_for_event interface changes. Use
lwpid_of.
(linux_detach): Don't delete the main lwp here.
(linux_join): Use my_waitpid. Avoid signal_pid. Use lwpid_of.
(status_pending_p): Don't consider explicitly suspended lwps.
(linux_wait_for_lwp): Take an integer pid instead of a lwp_info
pointer. Add OPTIONS argument. Change return type to int. Use
my_waitpid instead of sleeping. Handle WNOHANG. Use lwpid_of.
(linux_wait_for_event): Take an integer pid instead of a lwp_info
pointer. Add status pointer argument. Return a pid instead of a
status. Use lwpid_of. Adjust to linux_wait_for_lwp interface
changes. In non-stop mode, don't switch to a random thread.
(linux_wait): Rename to...
(linux_wait_1): ... this. Add target_options argument, and handle
it. Adjust to use resume_kind. Use lwpid_of. In non-stop mode,
don't handle the continue thread. Handle TARGET_WNOHANG. Merge
clean exit and signal exit code. Don't stop all threads in
non-stop mode. In all-stop mode, only stop all threads when
reporting a stop to GDB. Handle explicit thread stop requests.
(async_file_flush, async_file_mark): New.
(linux_wait): New.
(send_sigstop): Use lwpid_of.
(wait_for_sigstop): Use lwpid_of. Adjust to linux_wait_for_event
interface changes. In non-stop mode, don't switch to a random
thread.
(linux_resume_one_lwp): Use lwpid_of.
(linux_continue_one_thread, linux_queue_one_thread): Merge into ...
(linux_resume_one_thread): ... this. Handle resume_stop. In
non-stop mode, don't look for pending flag in all threads.
(resume_status_pending_p): Don't consider explicitly suspended
threads.
(my_waitpid): Reimplement. Emulate __WALL.
(linux_request_interrupt, linux_read_offsets, linux_xfer_siginfo):
Use lwpid_of.
(sigchld_handler, linux_supports_non_stop, linux_async)
(linux_start_non_stop): New.
(linux_target_ops): Register linux_supports_non_stop, linux_async
and linux_start_non_stop.
(initialize_low): Install SIGCHLD handler.
* thread-db.c (thread_db_create_event, find_one_thread)
(thread_db_get_tls_address): Use lwpid_of.
* win32-low.c (win32_detach): Adjust to use resume_kind.
(win32_wait): Add `options' argument.
* spu-low.c (spu_resume): Adjust to use resume_kind.
(spu_wait): Add `options' argument.
reinsert auto-delete breakpoints.
* mem-break.c (struct breakpoint): Change return type of handler to
int.
(set_breakpoint_at): Update handler type.
(reinsert_breakpoint_handler): Return 1 instead of calling
delete_breakpoint.
(reinsert_breakpoint_by_bp): Check for the original breakpoint before
setting a new one.
(check_breakpoints): Delete auto-delete breakpoints and return 2.
* mem-break.h (set_breakpoint_at): Update handler type.
* thread-db.c (thread_db_create_event, thread_db_create_event): Update.
* win32-low.c (auto_delete_breakpoint): New.
(get_child_debug_event): Use it.
(add_pid_to_list, pull_pid_from_list): New.
* linux-low.c (PTRACE_SETOPTIONS, PTRACE_GETEVENTMSG)
(PTRACE_O_TRACESYSGOOD, PTRACE_O_TRACEFORK, PTRACE_O_TRACEVFORK)
(PTRACE_O_TRACECLONE, PTRACE_O_TRACEEXEC, PTRACE_O_TRACEVFORKDONE)
(PTRACE_O_TRACEEXIT, PTRACE_EVENT_FORK, PTRACE_EVENT_VFORK)
(PTRACE_EVENT_CLONE, PTRACE_EVENT_EXEC, PTRACE_EVENT_VFORK_DONE)
(PTRACE_EVENT_EXIT, __WALL): Provide default definitions.
(stopped_pids, thread_db_active, must_set_ptrace_flags): New variables.
(using_threads): Always set to 1.
(handle_extended_wait): New.
(add_process): Do not set TID.
(linux_create_inferior): Set must_set_ptrace_flags.
(linux_attach_lwp): Remove TID argument. Do not check using_threads.
Use PTRACE_SETOPTIONS. Call new_thread_notify. Update all callers.
(linux_thread_alive): Rename TID argument to LWPID.
(linux_wait_for_process): Handle unknown processes. Do not use TID.
(linux_wait_for_event): Do not use TID or check using_threads. Update
call to dead_thread_notify. Call handle_extended_wait.
(linux_create_inferior): Use PTRACE_SETOPTIONS.
(send_sigstop): Delete sigstop_sent.
(wait_for_sigstop): Avoid TID.
(linux_supports_tracefork_flag, linux_tracefork_child, my_waitpid)
(linux_test_for_tracefork): New.
(linux_lookup_signals): Use thread_db_active and
linux_supports_tracefork_flag.
(initialize_low): Use thread_db_active and linux_test_for_tracefork.
* linux-low.h (get_process_thread): Avoid TID.
(struct process_ifo): Move thread_known and tid to the end. Remove
sigstop_sent.
(linux_attach_lwp, thread_db_init): Update prototypes.
* server.h (change_inferior_id): Delete prototype.
(add_pid_to_list, pull_pid_from_list): New prototypes.
* thread-db.c (thread_db_use_events): New.
(find_first_thread): Rename to...
(find_one_thread): ...this. Update callers and messages. Do not
call fatal. Check thread_db_use_events. Do not call
change_inferior_id or new_thread_notify.
(maybe_attach_thread): Update. Do not call new_thread_notify.
(thread_db_init): Set thread_db_use_events. Check use_events.
* utils.c (fatal, warning): Correct message prefix.
(thread_db_detach): Typo fix. Call target_mourn_inferior
instead of fixing up proc_handle.
(have_threads_callback, have_threads): New functions.
(thread_db_wait): Remove dead proc_handle.pid check. Only
translate PTIDs if we have registered threads. Check for new
threads if we have none.
(thread_db_create_inferior, thread_db_post_startup_inferior): Delete.
(find_new_threads_callback): Only enable event reporting if TID == 0.
(same_ptid_callback): New.
(thread_db_get_thread_local_address): Check for new threads.
(init_thread_db_ops): Don't set to_attach, to_create_inferior,
or to_post_startup_inferior.
* thread-db.c (thread_db_find_new_threads): Add prototype.
(thread_db_create_event): Check for the main thread before adding
a new thread.
(maybe_attach_thread): Only enable event reporting if TID == 0.
(thread_db_get_tls_address): Check for new threads.