We start from a process_info pointer, pass down process->pid, and
then the target_kill implementations need to find the process from the
pid again. Pass the process_info pointer down directly instead.
gdb/gdbserver/ChangeLog:
2018-07-13 Pedro Alves <palves@redhat.com>
* linux-low.c (linux_kill): Change parameter to process_info
pointer instead of pid. Adjust.
* lynx-low.c (lynx_kill): Likewise.
* nto-low.c (nto_kill): Likewise.
* spu-low.c (spu_kill): Likewise.
* win32-low.c (win32_kill): Likewise.
* server.c (handle_v_kill, kill_inferior_callback)
(detach_or_kill_for_exit): Adjust.
* target.c (kill_inferior): Change parameter to process_info
pointer instead of pid. Adjust.
* target.h (struct target_ops) <kill>: Change parameter to
process_info pointer instead of pid. Adjust all implementations
and callers.
(kill_inferior): Likewise.
We start from a process_info pointer, pass down process->pid, and then
the target_detach and target_join implementations need to find the
process from the pid again. Pass the process_info pointer down
directly instead.
gdb/gdbserver/ChangeLog:
2018-07-13 Pedro Alves <palves@redhat.com>
* linux-low.c (linux_detach, linux_join): Change parameter to
process_info pointer instead of pid. Adjust.
* lynx-low.c (lynx_detach, lynx_join): Likewise.
* nto-low.c (nto_detach): Likewise.
* spu-low.c (spu_detach, spu_join): Likewise.
* win32-low.c (win32_detach, win32_join): Likewise.
* server.c (handle_detach, detach_or_kill_for_exit): Adjust.
* target.h (struct target_ops) <detach, join>: Change parameter to
process_info pointer instead of pid. Adjust all implementations
and callers.
(detach_inferior, join_inferior): Rename 'pid' parameter to
'proc'.
There's a buildroot where I want to debug a binary, and I tried to
connect to it from outside, but got very weird errors like
architecture mismatch or protocol errors. At last, after switching on
'--debug' for gdbserver I found a message 'Can't open /proc/pid/'
message and suddenly found that I forgot to mount procfs in my
buildroot.
Make discovering the problem easier by making GDB / GDBserver warn
(even without --debug) if /proc can not be accessed.
Native debugging:
(gdb) start
Temporary breakpoint 1 at 0x400835: file test.c, line 10.
Starting program: /tmp/test
warning: /proc is not accessible.
GDBserver/remote debugging:
$ ./gdbserver :9999 ./gdbserver
gdbserver: /proc is not accessible.
gdb/ChangeLog:
2018-07-04 Vyacheslav Barinov <v.barinov@samsung.com>
Pedro Alves <palves@redhat.com>
* linux-nat.c (linux_init_ptrace): Rename to ...
(linux_init_ptrace_procfs): ... this. Call
linux_proc_init_warnings.
(linux_nat_target::post_attach)
(linux_nat_target::post_startup_inferior): Adjust.
* nat/linux-procfs.c (linux_proc_init_warnings): Define function.
* nat/linux-procfs.h (linux_proc_init_warnings): Declare function.
gdb/gdbserver/ChangeLog:
2018-07-04 Vyacheslav Barinov <v.barinov@samsung.com>
Pedro Alves <palves@redhat.com>
* linux-low.c (initialize_low): Call linux_proc_init_warnings.
Collect per client specific global data items into struct client_state,
which is similar in purpose to remote.c::remote_state.
gdbserver/ChangeLog
* server.h (struct client_state): New.
* server.c (cont_thread, general_thread, multi_process)
(report_fork_events, report_vfork_events, report_exec_events)
(report_thread_events, swbreak_feature, hwbreak_feature)
(vCont_supported, disable_randomization, pass_signals)
(program_signals, program_signals_p, last_status, last_ptid, own_buf):
Moved to client_state.
* remote-utils.c (remote_debug, noack_mode)
(transport_is_reliable): Moved to client_state.
* tracepoint.c (current_traceframe): Moved to client_state.
Update all callers.
* server.c, remote-utils.c, tracepoint.c, fork-child.c,
linux-low.c, remote-utils.h, target.c: Use client_state.
[This patch should go on top of "linux_qxfer_libraries_svr4: Use
std::string", I should have sent them together as a series.]
I noticed that linux_qxfer_libraries_svr4 used xml_escape_text, which
returns an std::string. That string is then copied into a larger
buffer. It would be more efficient if we had a version of
xml_escape_text which appended to an existing string instead of
returning a new one. This is what this patch does.
I manually verified that the output of linux_qxfer_libraries_svr4 didn't
change before/after the patch.
gdb/ChangeLog:
* common/xml-utils.c (xml_escape_text): Move code to...
(xml_escape_text_append): ... this new function.
* common/xml-utils.h (xml_escape_text_append): New declaration.
* unittests/xml-utils-selftests.c (test_xml_escape_text_append):
New function.
(_initialize_xml_utils): register test_xml_escape_text_append as
a selftest.
gdb/gdbserver/ChangeLog:
* linux-low.c (linux_qxfer_libraries_svr4): Use
xml_escape_text_append.
Remove the to_supports_btrace target method and instead rely on detecting errors
when trying to enable recording. This will also provide a suitable error
message explaining why recording is not possible.
For remote debugging, gdbserver will now always advertise branch tracing related
packets. When talking to an older GDB, this will cause GDB to try to enable
branch tracing and gdbserver to report a suitable error message every time.
An older gdbserver will not advertise branch tracing related packets if the
one-time check failed, so a newer GDB with this patch will fail to enable branch
tracing at remote_enable_btrace() rather than at btrace_enable(). The error
message is the same in both cases so there should be no user-visible change.
gdb/
* btrace.c (btrace_enable): Remove target_supports_btrace call.
* nat/linux-btrace.c (perf_event_pt_event_type): Move.
(kernel_supports_bts, kernel_supports_pt, linux_supports_bts)
(linux_supports_pt, linux_supports_btrace): Remove.
(linux_enable_bts): Call cpu_supports_bts.
* nat/linux-btrace.h (linux_supports_btrace): Remove.
* remote.c (remote_supports_btrace): Remove.
(init_remote_ops): Remove remote_supports_btrace.
* target-delegates.c: Regenerated.
* target.c (target_supports_btrace): Remove.
* target.h (target_ops) <to_supports_btrace>: Remove
(target_supports_btrace): Remove.
* x86-linux-nat.c (x86_linux_create_target): Remove
linux_supports_btrace.
gdbserver/
* linux-low.c (linux_target_ops): Remove linux_supports_btrace.
* nto-low.c (nto_target_ops): Remove NULL for supports_btrace.
* spu-low.c (spu_target_ops): Likewise.
* win32-low.c (win32_target_ops): Likewise.
* server.c (supported_btrace_packets): Report packets unconditionally.
* target.h (target_ops) <supports_btrace>: Remove.
(target_supports_btrace): Remove.
This removes make_cleanup_restore_current_thread from gdbserver,
replacing it with a use of scoped_restore.
2018-02-08 Tom Tromey <tom@tromey.com>
* linux-low.c (install_software_single_step_breakpoints): Use
make_scoped_restore.
* inferiors.c (make_cleanup_restore_current_thread): Remove.
(do_restore_current_thread_cleanup): Remove.
* gdbthread.h (make_cleanup_restore_current_thread): Don't
declare.
This patch makes linux_ptrace_attach_fail_reason and
linux_ptrace_attach_fail_reason_string return std::string. It also
replaces usages of struct buffer with std::string. This allows getting
rid of a cleanup in in linux_ptrace_attach_fail_reason_string and
simplifies the code in general.
Something that looks odd to me is that in
linux_ptrace_attach_fail_reason, if the two messages are appended, there
is no separating space or \n, so the result won't be very nice. I left
it as-is for now though.
gdb/ChangeLog:
* nat/linux-ptrace.h (linux_ptrace_attach_fail_reason): Return
std::string.
(linux_ptrace_attach_fail_reason_string): Likewise.
* nat/linux-ptrace.c (linux_ptrace_attach_fail_reason):
Likewise.
(linux_ptrace_attach_fail_reason_string): Likewise.
* linux-nat.c (attach_proc_task_lwp_callback): Adjust.
gdb/gdbserver/ChangeLog:
* linux-low.c (attach_proc_task_lwp_callback): Adjust to
linux_ptrace_attach_fail_reason_string now returning an
std::string.
(linux_attach): Likewise.
* thread-db.c (attach_thread): Likewise.
As described in PR 18749, GDB/GDBserver may get an error on accessing
memory or register because the thread may disappear. However, some
path doesn't expect the error. This patch fixes this problem by
marking the register unavailable when PTRACE_PEEKUSER fails instead
of throwing error.
gdb/gdbserver:
2018-01-16 Yao Qi <yao.qi@linaro.org>
PR gdb/18749
* linux-low.c (fetch_register): Call supply_register instead of
error.
These functions were modified in the previous patch series, but I forgot
to update some comments.
gdb/gdbserver/ChangeLog:
* linux-low.c (resume_status_pending_p): Update comment.
(need_step_over_p): Update comment.
Replace with for_each_thread.
gdb/gdbserver/ChangeLog:
* linux-low.c (linux_resume_one_thread): Return void, take
parameter directly.
(linux_resume): Use for_each_thread.
Replace with find_thread/for_each_thread. I inlined the callbacks,
because they are relatively simple.
gdb/gdbserver/ChangeLog:
* linux-low.c (select_singlestep_lwp_callback): Remove.
(count_events_callback): Remove.
(select_event_lwp_callback): Remove.
(select_event_lwp): Use find_thread/for_each_thread.
Replace with find_thread. Writing a lambda inline in directly in the if
conditions would be a bit messy, so I chose to assign them to variables
instead.
gdb/gdbserver/ChangeLog:
* linux-low.c (not_stopped_callback): Return bool, take filter
argument directly.
(linux_wait_for_event_filtered): Use find_thread.
(linux_wait_1): Likewise.
Replace with find_thread. We could almost use find_thread_ptid, except
that find_lwp_pid uses the pid of the input ptid of the lwp is 0, so the
behavior is not quite the same.
gdb/gdbserver/ChangeLog:
* linux-low.c (same_lwp): Remove.
(find_lwp_pid): Use find_thread.
Replace with for_each_thread with pid filtering. The callback becomes
trivial enough that it's better to inline it.
gdb/gdbserver/ChangeLog:
* linux-low.c (delete_lwp_callback): Remove.
(linux_mourn): Use for_each_thread.
Replace it with find_thread. I also modified the code a bit to use a
lambda and a boolean.
gdb/gdbserver/ChangeLog:
* linux-low.c (struct counter): Remove.
(second_thread_of_pid_p): Remove.
(last_thread_of_process_p): Use find_thread.
This changes maybe_disable_address_space_randomization to be an RAII
class, rather than having it return a cleanup.
Regression tested by the buildbot.
ChangeLog
2017-11-26 Tom Tromey <tom@tromey.com>
* nat/linux-personality.h (class
maybe_disable_address_space_randomization): New class.
(maybe_disable_address_space_randomization): Don't declare
function.
* nat/linux-personality.c (restore_personality)
(make_disable_asr_cleanup): Remove.
(maybe_disable_address_space_randomization): Now a constructor.
(~maybe_disable_address_space_randomization): New destructor.
* linux-nat.c (linux_nat_create_inferior): Update.
gdbserver/ChangeLog
2017-11-26 Tom Tromey <tom@tromey.com>
* linux-low.c (linux_create_inferior): Update.
Replace with for_each_thread.
gdb/gdbserver/ChangeLog:
* linux-low.c (kill_one_lwp_callback): Return void, take
argument directly, don't filter on pid.
(linux_kill): Use for_each_thread.
Replace with find_thread. Instead of setting the flag in the callback,
make the callback return true/false, and check the result against NULL
in the caller.
gdb/gdbserver/ChangeLog:
* linux-low.c (resume_status_pending_p): Return bool, remove
flag_p argument.
(linux_resume): Use find_thread.
Replace it with for_each_thread.
gdb/gdbserver/ChangeLog:
* linux-low.c (struct thread_resume_array): Remove.
(linux_set_resume_request): Return void, take arguments
directly.
(linux_resume): Use for_each_thread.
Replace with for_each_thread. I inlined unsuspend_one_lwp in
unsuspend_all_lwps, since it is very simple.
gdb/gdbserver/ChangeLog:
* linux-low.c (unsuspend_one_lwp): Remove.
(unsuspend_all_lwps): Use for_each_thread, inline code from
unsuspend_one_lwp.
Replace find_inferior with find_thread. Since it may be useful in the
future, I added another overload to find_thread which filters based on a
ptid (using ptid_t::matches), so now iterate_over_lwps doesn't have to
do the filtering itself. iterate_over_lwps_filter is removed and
inlined into iterate_over_lwps.
gdb/gdbserver/ChangeLog:
* gdbthread.h (find_thread): Add overload with ptid_t filter.
* linux-low.c (struct iterate_over_lwps_args): Remove.
(iterate_over_lwps_filter): Remove.
(iterate_over_lwps): Use find_thread.
Replace with for_each_thread, and inline code from
reset_lwp_ptrace_options_callback.
gdb/gdbserver/ChangeLog:
* linux-low.c (reset_lwp_ptrace_options_callback): Remove.
(linux_handle_new_gdb_connection): Use for_each_thread, inline
code from reset_lwp_ptrace_options_callback.
This patch makes the syscalls_to_catch field of process_info an
std::vector<int>. The process_info structure must now be
newed/deleted.
In handle_extended_wait, the code that handles exec events destroys the
existing process_info and creates a new one. It moves the content of
syscalls_to_catch from the old to the new vector. I used std::move for
that (through an intermediary variable), which should have the same
behavior as the old code.
gdb/gdbserver/ChangeLog:
* inferiors.h (struct process_info): Add constructor, initialize
fields..
<syscalls_to_catch>: Change type to std::vector<int>.
* inferiors.c (add_process): Allocate process_info with new.
(remove_process): Free process_info with delete.
* linux-low.c (handle_extended_wait): Adjust.
(gdb_catching_syscalls_p, gdb_catch_this_syscall_p): Adjust.
* server.c (handle_general_set): Adjust.
It happens often that we want to iterate or find threads restricted to a
given pid. I think it's worth having an overload to help with this.
Right now there is a single user of each of the find_thread and
for_each_thread overload, but as we replace the usages of find_inferior
with for_each_thread/find_thread, more usages will pop up.
gdb/gdbserver/ChangeLog:
* gdbthread.h (find_thread, for_each_thread): New functions.
* inferiors.c (thread_of_pid): Remove.
(find_any_thread_of_pid): Use find_thread.
* linux-low.c (num_lwps): Use for_each_thread.
Remove the usage of inferior_list for the all_threads list in
gdbserver. The entry field in thread_info is removed, and replaced by a
simple ptid field.
I added some functions to iterate (for_each_thread) and find threads
(find_thread). However, changing all the users of find_inferior & co to
use these new functions would have made the patch way too big. So I
opted instead to make find_inferior & co some shims, so that the
existing code only needs to be updated minimally. We can then update
the existing code to use the new functions incrementally (I've started
to do the work, but I'll post it afterwards, see [1] if you want a peek).
This patch has been built-tested on all relevant platforms, except
lynx. I also regtested using the native-gdbserver and
native-extended-gdbserver boards on x86.
[1] https://github.com/simark/binutils-gdb/commits/kill-inferior-list-entry
gdb/gdbserver/ChangeLog:
* inferiors.h: (struct inferior_list): Remove.
(struct inferior_list_entry); Remove.
(add_inferior_to_list, clear_inferior_list, one_inferior_p,
A_I_NEXT, ALL_INFERIORS_TYPE, ALL_INFERIORS, remove_inferior,
get_first_inferior): Remove.
(for_each_inferior, for_each_inferior_with_data, find_inferior,
find_inferior_id, find_inferior_in_random): Change signature.
* inferiors.c (all_threads): Change type to
std::list<thread_info *>.
(get_thread): Remove macro.
(find_inferior, find_inferior_id): Change signature, implement
using find_thread.
(find_inferior_in_random): Change signature, implement using
find_thread_in_random.
(for_each_inferior, for_each_inferior_with_data): Change
signature, implement using for_each_thread.
(add_inferior_to_list, remove_inferior): Remove.
(add_thread, get_first_thread, thread_of_pid,
find_any_thread_of_pid, free_one_thread, remove_thread): Update.
(get_first_inferior, one_inferior_p, clear_inferior_list):
Remove.
(clear_inferiors, get_thread_process): Update.
* gdbthread.h: Include <list>.
(struct thread_info) <entry>: Remove field.
<id>: New field.
(all_threads): Change type to std::list<thread_info *>.
(get_first_inferior): Add doc.
(find_thread, for_each_thread, find_thread_in_random): New
functions.
(current_ptid, pid_of, ptid_of, lwpid_of): Update.
* linux-arm-low.c (update_registers_callback): Update.
* linux-low.c (second_thread_of_pid_p): Update.
(kill_one_lwp_callback, linux_detach_lwp_callback,
delete_lwp_callback, status_pending_p_callback, same_lwp,
find_lwp_pid, num_lwps, iterate_over_lwps_filter,
iterate_over_lwps, not_stopped_callback,
resume_stopped_resumed_lwps, count_events_callback,
select_singlestep_lwp_callback, select_event_lwp_callback,
unsuspend_one_lwp, linux_wait_1, send_sigstop_callback,
suspend_and_send_sigstop_callback, wait_for_sigstop,
stuck_in_jump_pad_callback, move_out_of_jump_pad_callback,
lwp_running, linux_set_resume_request, resume_status_pending_p,
need_step_over_p, start_step_over, linux_resume_one_thread,
proceed_one_lwp, unsuspend_and_proceed_one_lwp,
reset_lwp_ptrace_options_callback): Update.
* linux-mips-low.c (update_watch_registers_callback): Update.
* regcache.c (regcache_invalidate_one, regcache_invalidate):
Update.
(free_register_cache_thread_one): Remove.
(regcache_release): Update.
* server.c (handle_btrace_enable_bts, handle_btrace_enable_pt,
handle_qxfer_threads_worker): Update.
(handle_query): Update, use list iterator.
(visit_actioned_threads, handle_pending_status,
queue_stop_reply_callback, gdb_wants_all_threads_stopped,
clear_pending_status_callback, set_pending_status_callback,
find_status_pending_thread_callback, handle_status,
process_serial_event): Update.
* target.c (thread_search_callback): Update.
* thread-db.c (thread_db_get_tls_address): Update.
* tracepoint.c (tracepoint_finished_step, tracepoint_was_hit):
Update.
* win32-i386-low.c (update_debug_registers_callback): Update.
* win32-low.c (delete_thread_info, child_delete_thread,
continue_one_thread, suspend_one_thread,
get_child_debug_event): Adjust.
Remove the usage of inferior_list for the all_processes list in
gdbserver, replace it with an std::list. The entry field in process_info
is removed, and replaced by a simple pid field.
The pid_of macro, used for both processes and threads, is replaced with
separate functions. For completeness, I changed ptid_of and lwpid_of to
functions as well.
gdb/gdbserver/ChangeLog:
* gdbthread.h (ptid_of, pid_of, lwpid_of): New functions.
* inferiors.h: Include <list>.
(struct process_info) <entry>: Remove field.
<pid>: New field.
(pid_of): Change macro to function.
(ptid_of, lwpid_of): Remove macro.
(all_processes): Change type to std::list<process_info *>.
(ALL_PROCESSES): Remove macro.
(for_each_process, find_process): New function.
* inferiors.c (all_processes): Change type to
std::list<process_info *>.
(find_thread_process): Adjust.
(add_process): Likewise.
(remove_process): Likewise.
(find_process_pid): Likewise.
(get_first_process): Likewise.
(started_inferior_callback): Remove.
(have_started_inferiors_p): Adjust.
(attached_inferior_callback): Remove.
(have_attached_inferiors_p): Adjust.
* linux-low.c (check_zombie_leaders): Likewise.
* linux-x86-low.c (x86_arch_setup_process_callback): Remove.
(x86_linux_update_xmltarget): Adjust.
* server.c (handle_query): Likewise.
(gdb_reattached_process): Remove.
(handle_status): Adjust.
(kill_inferior_callback): Likewise.
(detach_or_kill_inferior): Remove.
(print_started_pid): Likewise.
(print_attached_pid): Likewise.
(detach_or_kill_for_exit): Update.
(process_serial_event): Likewise.
* linux-arm-low.c (arm_new_fork): Likewise.
I have the goal of "poisoning" the XNEW/xfree-family of functions, so
that we catch their usages with non-POD types. A few things need to be
fixed in the mean time, this is one.
The common lwp code in linux-nat.c and gdbserver/linux-low.c xfrees the
private lwp data of type arch_lwp_info. However, that type is opaque
from its point of view, as its defined differently in each arch-specific
implementation. This trips on the std::is_pod<T> check, since the
compiler can't tell whether the type is POD or not if it doesn't know
about it.
My initial patch [1] made a class hierarchy with a virtual destructor.
However, as Pedro pointed out, we only have one native architecture at
the time built in gdb and gdbserver, so that's overkill. Instead, we
can move the responsibility of free'ing arch_lwp_info to the arch code
(which is also the one that allocated it in the first place). This is
what this patch does.
Also, I had the concern that if we wanted to use C++ features in these
structures, we would have a problem with the one-definition rule.
However, since a build will only have one version of arch_lwp_info,
that's not a problem.
There are changes in arch-specific files, I was only able to built-test
this patch with the following cross-compilers:
aarch64-linux-gnu
alpha-linux-gnu
arm-linux-gnueabihf
hppa-linux-gnu
m68k-linux-gnu
mips64el-linux-gnuabi64
powerpc64-linux-gnu
s390x-linux-gnu
sh4-linux-gnu
sparc64-linux-gnu
x86_64-linux-gnu
x86_64-w64-mingw32
A buildbot run didn't find any regression.
[1] https://sourceware.org/ml/gdb-patches/2017-08/msg00255.html
gdb/ChangeLog:
* linux-nat.h (linux_nat_set_delete_thread): New declaration.
* linux-nat.c (linux_nat_delete_thread): New variable.
(lwp_free): Invoke linux_nat_delete_thread if set.
(linux_nat_set_delete_thread): New function.
* aarch64-linux-nat.c (_initialize_aarch64_linux_nat): Assign
thread delete callback.
* arm-linux-nat.c (arm_linux_delete_thread): New function.
(_initialize_arm_linux_nat): Assign thread delete callback.
* s390-linux-nat.c (s390_delete_thread): New function.
(_initialize_s390_nat): Assign thread delete callback.
* x86-linux-nat.c (x86_linux_add_target): Likewise.
* nat/aarch64-linux.c (aarch64_linux_delete_thread): New
function.
* nat/aarch64-linux.h (aarch64_linux_delete_thread): New
declaration.
* nat/x86-linux.c (x86_linux_delete_thread): New function.
* nat/x86-linux.h (x86_linux_delete_thread): New declaration.
gdb/gdbserver/ChangeLog:
* linux-aarch64-low.c (the_low_target): Add thread delete
callback.
* linux-arm-low.c (arm_delete_thread): New function.
(the_low_target): Add thread delete callback.
* linux-bfin-low.c (the_low_target): Likewise.
* linux-crisv32-low.c (the_low_target): Likewise.
* linux-low.c (delete_lwp): Invoke delete_thread callback if
set.
* linux-low.h (struct linux_target_ops) <delete_thread>: New
field.
* linux-m32r-low.c (the_low_target): Add thread delete callback.
* linux-mips-low.c (mips_linux_delete_thread): New function.
(the_low_target): Add thread delete callback.
* linux-ppc-low.c (the_low_target): Likewise.
* linux-s390-low.c (the_low_target): Likewise.
* linux-sh-low.c (the_low_target): Likewise.
* linux-tic6x-low.c (the_low_target): Likewise.
* linux-tile-low.c (the_low_target): Likewise.
* linux-x86-low.c (the_low_target): Likewise.
* linux-xtensa-low.c (the_low_target): Likewise.
Commit 8629910955 ("Add thread_db_notice_clone to gdbserver")
introduced calls into libthread_db without making sure that the
current thread is pointing to a know-stopped thread. This resulted in
sometimes thread_db_notice_clone failing->find_one_thread failing like
this, as seen when running gdb.threads/multi-create-ns-info-thr.exp:
~~~
Thread <6> executing
Thread <7> executing
gdbserver: PID mismatch! Expected 27472, got 27471
gdbserver: Cannot find thread after clone.
Thread <1000> executing
Thread <1001> executing
~~~
Things go south from here and sometimes that ends up resulting in
gdbserver crashing and the test failing.
gdb/gdbserver/ChangeLog:
2017-09-29 Pedro Alves <palves@redhat.com>
* linux-low.c (handle_extended_wait): Pass parent thread instead
of process to thread_db_notice_clone.
* linux-low.h (thread_db_notice_clone): Replace parent process
parameter with parent thread parameter.
* thread-db.c (find_one_thread): Add comment.
(thread_db_notice_clone): Replace parent process parameter with
parent thread parameter. Temporarily switch to the parent thread.
This patch adds support to remote targets for converting a thread
handle to a thread_info struct pointer.
A thread handle is fetched via a "handle" attribute which has been
added to the qXfer:threads:read query packet. An implementation is
provided in gdbserver for targets using the Linux kernel.
gdb/gdbserver/ChangeLog:
* linux-low.h (struct lwp_info): Add new field, thread_handle.
(thread_db_thread_handle): Declare.
* linux-low.c (linux_target_ops): Initialize thread_handle.
* server.c (handle_qxfer_threads_worker): Add support for
"handle" attribute.
* target.h (struct target_ops): Add new function pointer,
thread_handle.
(target_thread_handle): Define.
* thread-db.c (find_one_thread, attach_thread): Set thread_handle
field in lwp.
(thread_db_thread_handle): New function.
gdb/ChangeLog:
* remote.c (vector): Include.
(struct private_thread_info): Add field, thread_handle.
(free_private_thread_info): Deallocate storage associated with
thread handle.
(get_private_info_thread): Initialize `thread_handle' field.
(struct thread_item): Add field, thread_handle.
(clear_threads_listing_context): Deallocate storage associated
with thread handle.
(start_thread): Add support for "handle" attribute.
(thread_attributes): Add "handle".
(remote_get_threads_with_qthreadinfo): Initialize thread_handle
field.
(remote_update_thread_list): Update thread_handle.
(remote_thread_handle_to_thread_info): New function.
(init_remote_ops): Initialize to_thread_handle_to_thread_info.
While working on a patch for fetching a thread handle in gdbserver, I
ran into a circumstance in which tests in gdb.mi/mi-nsmoribund.exp
would occasionally fail. Over a large enough number of runs, it would
fail roughly 2% of the time.
That thread handle patch caused find_one_thread() to be called on
every stop. find_one_thread() calls td_ta_map_lwp2thr() which, in
turn, can cause ps_get_thread_area() to be called.
ps_get_thread_area() makes a call to ptrace() for getting the thread
area address. If this should happen when the thread is not stopped,
the call to ptrace will return error which in turn propogates back to
find_one_thread(). find_one_thread() calls error() in this instance
which causes the program to die.
This patch causes find_one_thread() to be called upon reciept of a
clone event. Since the clone is stopped, the circumstances described
above cannot occur.
gdb/gdbserver/ChangeLog:
* linux-low.c (handle_extended_wait): Call thread_db_notice_clone().
* linux-low.h (thread_db_notice_clone): Declare.
* thread-db.c (thread_db_notice_clone): New function.
Pedro Alves
Vyacheslav Barinov
Tom Tromey
Stan Cox
Simon Marchi
Markus Metzger
James Clarke
Simon Marchi
Yao Qi
Joel Brobecker
Kevin Buettner