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5b6d1e4fa4
This commit adds multi-target support to GDB. What this means is that
with this commit, GDB can now be connected to different targets at the
same time. E.g., you can debug a live native process and a core dump
at the same time, connect to multiple gdbservers, etc.
Actually, the word "target" is overloaded in gdb. We already have a
target stack, with pushes several target_ops instances on top of one
another. We also have "info target" already, which means something
completely different to what this patch does.
So from here on, I'll be using the "target connections" term, to mean
an open process_stratum target, pushed on a target stack. This patch
makes gdb have multiple target stacks, and multiple process_stratum
targets open simultaneously. The user-visible changes / commands will
also use this terminology, but of course it's all open to debate.
User-interface-wise, not that much changes. The main difference is
that each inferior may have its own target connection.
A target connection (e.g., a target extended-remote connection) may
support debugging multiple processes, just as before.
Say you're debugging against gdbserver in extended-remote mode, and
you do "add-inferior" to prepare to spawn a new process, like:
(gdb) target extended-remote :9999
...
(gdb) start
...
(gdb) add-inferior
Added inferior 2
(gdb) inferior 2
[Switching to inferior 2 [<null>] (<noexec>)]
(gdb) file a.out
...
(gdb) start
...
At this point, you have two inferiors connected to the same gdbserver.
With this commit, GDB will maintain a target stack per inferior,
instead of a global target stack.
To preserve the behavior above, by default, "add-inferior" makes the
new inferior inherit a copy of the target stack of the current
inferior. Same across a fork - the child inherits a copy of the
target stack of the parent. While the target stacks are copied, the
targets themselves are not. Instead, target_ops is made a
refcounted_object, which means that target_ops instances are
refcounted, which each inferior counting for a reference.
What if you want to create an inferior and connect it to some _other_
target? For that, this commit introduces a new "add-inferior
-no-connection" option that makes the new inferior not share the
current inferior's target. So you could do:
(gdb) target extended-remote :9999
Remote debugging using :9999
...
(gdb) add-inferior -no-connection
[New inferior 2]
Added inferior 2
(gdb) inferior 2
[Switching to inferior 2 [<null>] (<noexec>)]
(gdb) info inferiors
Num Description Executable
1 process 18401 target:/home/pedro/tmp/main
* 2 <null>
(gdb) tar extended-remote :10000
Remote debugging using :10000
...
(gdb) info inferiors
Num Description Executable
1 process 18401 target:/home/pedro/tmp/main
* 2 process 18450 target:/home/pedro/tmp/main
(gdb)
A following patch will extended "info inferiors" to include a column
indicating which connection an inferior is bound to, along with a
couple other UI tweaks.
Other than that, debugging is the same as before. Users interact with
inferiors and threads as before. The only difference is that
inferiors may be bound to processes running in different machines.
That's pretty much all there is to it in terms of noticeable UI
changes.
On to implementation.
Since we can be connected to different systems at the same time, a
ptid_t is no longer a unique identifier. Instead a thread can be
identified by a pair of ptid_t and 'process_stratum_target *', the
later being the instance of the process_stratum target that owns the
process/thread. Note that process_stratum_target inherits from
target_ops, and all process_stratum targets inherit from
process_stratum_target. In earlier patches, many places in gdb were
converted to refer to threads by thread_info pointer instead of
ptid_t, but there are still places in gdb where we start with a
pid/tid and need to find the corresponding inferior or thread_info
objects. So you'll see in the patch many places adding a
process_stratum_target parameter to functions that used to take only a
ptid_t.
Since each inferior has its own target stack now, we can always find
the process_stratum target for an inferior. That is done via a
inf->process_target() convenience method.
Since each inferior has its own target stack, we need to handle the
"beneath" calls when servicing target calls. The solution I settled
with is just to make sure to switch the current inferior to the
inferior you want before making a target call. Not relying on global
context is just not feasible in current GDB. Fortunately, there
aren't that many places that need to do that, because generally most
code that calls target methods already has the current context
pointing to the right inferior/thread. Note, to emphasize -- there's
no method to "switch to this target stack". Instead, you switch the
current inferior, and that implicitly switches the target stack.
In some spots, we need to iterate over all inferiors so that we reach
all target stacks.
Native targets are still singletons. There's always only a single
instance of such targets.
Remote targets however, we'll have one instance per remote connection.
The exec target is still a singleton. There's only one instance. I
did not see the point of instanciating more than one exec_target
object.
After vfork, we need to make sure to push the exec target on the new
inferior. See exec_on_vfork.
For type safety, functions that need a {target, ptid} pair to identify
a thread, take a process_stratum_target pointer for target parameter
instead of target_ops *. Some shared code in gdb/nat/ also need to
gain a target pointer parameter. This poses an issue, since gdbserver
doesn't have process_stratum_target, only target_ops. To fix this,
this commit renames gdbserver's target_ops to process_stratum_target.
I think this makes sense. There's no concept of target stack in
gdbserver, and gdbserver's target_ops really implements a
process_stratum-like target.
The thread and inferior iterator functions also gain
process_stratum_target parameters. These are used to be able to
iterate over threads and inferiors of a given target. Following usual
conventions, if the target pointer is null, then we iterate over
threads and inferiors of all targets.
I tried converting "add-inferior" to the gdb::option framework, as a
preparatory patch, but that stumbled on the fact that gdb::option does
not support file options yet, for "add-inferior -exec". I have a WIP
patchset that adds that, but it's not a trivial patch, mainly due to
need to integrate readline's filename completion, so I deferred that
to some other time.
In infrun.c/infcmd.c, the main change is that we need to poll events
out of all targets. See do_target_wait. Right after collecting an
event, we switch the current inferior to an inferior bound to the
target that reported the event, so that target methods can be used
while handling the event. This makes most of the code transparent to
multi-targets. See fetch_inferior_event.
infrun.c:stop_all_threads is interesting -- in this function we need
to stop all threads of all targets. What the function does is send an
asynchronous stop request to all threads, and then synchronously waits
for events, with target_wait, rinse repeat, until all it finds are
stopped threads. Now that we have multiple targets, it's not
efficient to synchronously block in target_wait waiting for events out
of one target. Instead, we implement a mini event loop, with
interruptible_select, select'ing on one file descriptor per target.
For this to work, we need to be able to ask the target for a waitable
file descriptor. Such file descriptors already exist, they are the
descriptors registered in the main event loop with add_file_handler,
inside the target_async implementations. This commit adds a new
target_async_wait_fd target method that just returns the file
descriptor in question. See wait_one / stop_all_threads in infrun.c.
The 'threads_executing' global is made a per-target variable. Since
it is only relevant to process_stratum_target targets, this is where
it is put, instead of in target_ops.
You'll notice that remote.c includes some FIXME notes. These refer to
the fact that the global arrays that hold data for the remote packets
supported are still globals. For example, if we connect to two
different servers/stubs, then each might support different remote
protocol features. They might even be different architectures, like
e.g., one ARM baremetal stub, and a x86 gdbserver, to debug a
host/controller scenario as a single program. That isn't going to
work correctly today, because of said globals. I'm leaving fixing
that for another pass, since it does not appear to be trivial, and I'd
rather land the base work first. It's already useful to be able to
debug multiple instances of the same server (e.g., a distributed
cluster, where you have full control over the servers installed), so I
think as is it's already reasonable incremental progress.
Current limitations:
- You can only resume more that one target at the same time if all
targets support asynchronous debugging, and support non-stop mode.
It should be possible to support mixed all-stop + non-stop
backends, but that is left for another time. This means that
currently in order to do multi-target with gdbserver you need to
issue "maint set target-non-stop on". I would like to make that
mode be the default, but we're not there yet. Note that I'm
talking about how the target backend works, only. User-visible
all-stop mode works just fine.
- As explained above, connecting to different remote servers at the
same time is likely to produce bad results if they don't support the
exact set of RSP features.
FreeBSD updates courtesy of John Baldwin.
gdb/ChangeLog:
2020-01-10 Pedro Alves <palves@redhat.com>
John Baldwin <jhb@FreeBSD.org>
* aarch64-linux-nat.c
(aarch64_linux_nat_target::thread_architecture): Adjust.
* ada-tasks.c (print_ada_task_info): Adjust find_thread_ptid call.
(task_command_1): Likewise.
* aix-thread.c (sync_threadlists, aix_thread_target::resume)
(aix_thread_target::wait, aix_thread_target::fetch_registers)
(aix_thread_target::store_registers)
(aix_thread_target::thread_alive): Adjust.
* amd64-fbsd-tdep.c: Include "inferior.h".
(amd64fbsd_get_thread_local_address): Pass down target.
* amd64-linux-nat.c (ps_get_thread_area): Use ps_prochandle
thread's gdbarch instead of target_gdbarch.
* break-catch-sig.c (signal_catchpoint_print_it): Adjust call to
get_last_target_status.
* break-catch-syscall.c (print_it_catch_syscall): Likewise.
* breakpoint.c (breakpoints_should_be_inserted_now): Consider all
inferiors.
(update_inserted_breakpoint_locations): Skip if inferiors with no
execution.
(update_global_location_list): When handling moribund locations,
find representative inferior for location's pspace, and use thread
count of its process_stratum target.
* bsd-kvm.c (bsd_kvm_target_open): Pass target down.
* bsd-uthread.c (bsd_uthread_target::wait): Use
as_process_stratum_target and adjust thread_change_ptid and
add_thread calls.
(bsd_uthread_target::update_thread_list): Use
as_process_stratum_target and adjust find_thread_ptid,
thread_change_ptid and add_thread calls.
* btrace.c (maint_btrace_packet_history_cmd): Adjust
find_thread_ptid call.
* corelow.c (add_to_thread_list): Adjust add_thread call.
(core_target_open): Adjust add_thread_silent and thread_count
calls.
(core_target::pid_to_str): Adjust find_inferior_ptid call.
* ctf.c (ctf_target_open): Adjust add_thread_silent call.
* event-top.c (async_disconnect): Pop targets from all inferiors.
* exec.c (add_target_sections): Push exec target on all inferiors
sharing the program space.
(remove_target_sections): Remove the exec target from all
inferiors sharing the program space.
(exec_on_vfork): New.
* exec.h (exec_on_vfork): Declare.
* fbsd-nat.c (fbsd_add_threads): Add fbsd_nat_target parameter.
Pass it down.
(fbsd_nat_target::update_thread_list): Adjust.
(fbsd_nat_target::resume): Adjust.
(fbsd_handle_debug_trap): Add fbsd_nat_target parameter. Pass it
down.
(fbsd_nat_target::wait, fbsd_nat_target::post_attach): Adjust.
* fbsd-tdep.c (fbsd_corefile_thread): Adjust
get_thread_arch_regcache call.
* fork-child.c (gdb_startup_inferior): Pass target down to
startup_inferior and set_executing.
* gdbthread.h (struct process_stratum_target): Forward declare.
(add_thread, add_thread_silent, add_thread_with_info)
(in_thread_list): Add process_stratum_target parameter.
(find_thread_ptid(inferior*, ptid_t)): New overload.
(find_thread_ptid, thread_change_ptid): Add process_stratum_target
parameter.
(all_threads()): Delete overload.
(all_threads, all_non_exited_threads): Add process_stratum_target
parameter.
(all_threads_safe): Use brace initialization.
(thread_count): Add process_stratum_target parameter.
(set_resumed, set_running, set_stop_requested, set_executing)
(threads_are_executing, finish_thread_state): Add
process_stratum_target parameter.
(switch_to_thread): Use is_current_thread.
* i386-fbsd-tdep.c: Include "inferior.h".
(i386fbsd_get_thread_local_address): Pass down target.
* i386-linux-nat.c (i386_linux_nat_target::low_resume): Adjust.
* inf-child.c (inf_child_target::maybe_unpush_target): Remove
have_inferiors check.
* inf-ptrace.c (inf_ptrace_target::create_inferior)
(inf_ptrace_target::attach): Adjust.
* infcall.c (run_inferior_call): Adjust.
* infcmd.c (run_command_1): Pass target to
scoped_finish_thread_state.
(proceed_thread_callback): Skip inferiors with no execution.
(continue_command): Rename 'all_threads' local to avoid hiding
'all_threads' function. Adjust get_last_target_status call.
(prepare_one_step): Adjust set_running call.
(signal_command): Use user_visible_resume_target. Compare thread
pointers instead of inferior_ptid.
(info_program_command): Adjust to pass down target.
(attach_command): Mark target's 'thread_executing' flag.
(stop_current_target_threads_ns): New, factored out from ...
(interrupt_target_1): ... this. Switch inferior before making
target calls.
* inferior-iter.h
(struct all_inferiors_iterator, struct all_inferiors_range)
(struct all_inferiors_safe_range)
(struct all_non_exited_inferiors_range): Filter on
process_stratum_target too. Remove explicit.
* inferior.c (inferior::inferior): Push dummy target on target
stack.
(find_inferior_pid, find_inferior_ptid, number_of_live_inferiors):
Add process_stratum_target parameter, and pass it down.
(have_live_inferiors): Adjust.
(switch_to_inferior_and_push_target): New.
(add_inferior_command, clone_inferior_command): Handle
"-no-connection" parameter. Use
switch_to_inferior_and_push_target.
(_initialize_inferior): Mention "-no-connection" option in
the help of "add-inferior" and "clone-inferior" commands.
* inferior.h: Include "process-stratum-target.h".
(interrupt_target_1): Use bool.
(struct inferior) <push_target, unpush_target, target_is_pushed,
find_target_beneath, top_target, process_target, target_at,
m_stack>: New.
(discard_all_inferiors): Delete.
(find_inferior_pid, find_inferior_ptid, number_of_live_inferiors)
(all_inferiors, all_non_exited_inferiors): Add
process_stratum_target parameter.
* infrun.c: Include "gdb_select.h" and <unordered_map>.
(target_last_proc_target): New global.
(follow_fork_inferior): Push target on new inferior. Pass target
to add_thread_silent. Call exec_on_vfork. Handle target's
reference count.
(follow_fork): Adjust get_last_target_status call. Also consider
target.
(follow_exec): Push target on new inferior.
(struct execution_control_state) <target>: New field.
(user_visible_resume_target): New.
(do_target_resume): Call target_async.
(resume_1): Set target's threads_executing flag. Consider resume
target.
(commit_resume_all_targets): New.
(proceed): Also consider resume target. Skip threads of inferiors
with no execution. Commit resumtion in all targets.
(start_remote): Pass current inferior to wait_for_inferior.
(infrun_thread_stop_requested): Consider target as well. Pass
thread_info pointer to clear_inline_frame_state instead of ptid.
(infrun_thread_thread_exit): Consider target as well.
(random_pending_event_thread): New inferior parameter. Use it.
(do_target_wait): Rename to ...
(do_target_wait_1): ... this. Add inferior parameter, and pass it
down.
(threads_are_resumed_pending_p, do_target_wait): New.
(prepare_for_detach): Adjust calls.
(wait_for_inferior): New inferior parameter. Handle it. Use
do_target_wait_1 instead of do_target_wait.
(fetch_inferior_event): Adjust. Switch to representative
inferior. Pass target down.
(set_last_target_status): Add process_stratum_target parameter.
Save target in global.
(get_last_target_status): Add process_stratum_target parameter and
handle it.
(nullify_last_target_wait_ptid): Clear 'target_last_proc_target'.
(context_switch): Check inferior_ptid == null_ptid before calling
inferior_thread().
(get_inferior_stop_soon): Pass down target.
(wait_one): Rename to ...
(poll_one_curr_target): ... this.
(struct wait_one_event): New.
(wait_one): New.
(stop_all_threads): Adjust.
(handle_no_resumed, handle_inferior_event): Adjust to consider the
event's target.
(switch_back_to_stepped_thread): Also consider target.
(print_stop_event): Update.
(normal_stop): Update. Also consider the resume target.
* infrun.h (wait_for_inferior): Remove declaration.
(user_visible_resume_target): New declaration.
(get_last_target_status, set_last_target_status): New
process_stratum_target parameter.
* inline-frame.c (clear_inline_frame_state(ptid_t)): Add
process_stratum_target parameter, and use it.
(clear_inline_frame_state (thread_info*)): New.
* inline-frame.c (clear_inline_frame_state(ptid_t)): Add
process_stratum_target parameter.
(clear_inline_frame_state (thread_info*)): Declare.
* linux-fork.c (delete_checkpoint_command): Pass target down to
find_thread_ptid.
(checkpoint_command): Adjust.
* linux-nat.c (linux_nat_target::follow_fork): Switch to thread
instead of just tweaking inferior_ptid.
(linux_nat_switch_fork): Pass target down to thread_change_ptid.
(exit_lwp): Pass target down to find_thread_ptid.
(attach_proc_task_lwp_callback): Pass target down to
add_thread/set_running/set_executing.
(linux_nat_target::attach): Pass target down to
thread_change_ptid.
(get_detach_signal): Pass target down to find_thread_ptid.
Consider last target status's target.
(linux_resume_one_lwp_throw, resume_lwp)
(linux_handle_syscall_trap, linux_handle_extended_wait, wait_lwp)
(stop_wait_callback, save_stop_reason, linux_nat_filter_event)
(linux_nat_wait_1, resume_stopped_resumed_lwps): Pass target down.
(linux_nat_target::async_wait_fd): New.
(linux_nat_stop_lwp, linux_nat_target::thread_address_space): Pass
target down.
* linux-nat.h (linux_nat_target::async_wait_fd): Declare.
* linux-tdep.c (get_thread_arch_regcache): Pass target down.
* linux-thread-db.c (struct thread_db_info::process_target): New
field.
(add_thread_db_info): Save target.
(get_thread_db_info): New process_stratum_target parameter. Also
match target.
(delete_thread_db_info): New process_stratum_target parameter.
Also match target.
(thread_from_lwp): Adjust to pass down target.
(thread_db_notice_clone): Pass down target.
(check_thread_db_callback): Pass down target.
(try_thread_db_load_1): Always push the thread_db target.
(try_thread_db_load, record_thread): Pass target down.
(thread_db_target::detach): Pass target down. Always unpush the
thread_db target.
(thread_db_target::wait, thread_db_target::mourn_inferior): Pass
target down. Always unpush the thread_db target.
(find_new_threads_callback, thread_db_find_new_threads_2)
(thread_db_target::update_thread_list): Pass target down.
(thread_db_target::pid_to_str): Pass current inferior down.
(thread_db_target::get_thread_local_address): Pass target down.
(thread_db_target::resume, maintenance_check_libthread_db): Pass
target down.
* nto-procfs.c (nto_procfs_target::update_thread_list): Adjust.
* procfs.c (procfs_target::procfs_init_inferior): Declare.
(proc_set_current_signal, do_attach, procfs_target::wait): Adjust.
(procfs_init_inferior): Rename to ...
(procfs_target::procfs_init_inferior): ... this and adjust.
(procfs_target::create_inferior, procfs_notice_thread)
(procfs_do_thread_registers): Adjust.
* ppc-fbsd-tdep.c: Include "inferior.h".
(ppcfbsd_get_thread_local_address): Pass down target.
* proc-service.c (ps_xfer_memory): Switch current inferior and
program space as well.
(get_ps_regcache): Pass target down.
* process-stratum-target.c
(process_stratum_target::thread_address_space)
(process_stratum_target::thread_architecture): Pass target down.
* process-stratum-target.h
(process_stratum_target::threads_executing): New field.
(as_process_stratum_target): New.
* ravenscar-thread.c
(ravenscar_thread_target::update_inferior_ptid): Pass target down.
(ravenscar_thread_target::wait, ravenscar_add_thread): Pass target
down.
* record-btrace.c (record_btrace_target::info_record): Adjust.
(record_btrace_target::record_method)
(record_btrace_target::record_is_replaying)
(record_btrace_target::fetch_registers)
(get_thread_current_frame_id, record_btrace_target::resume)
(record_btrace_target::wait, record_btrace_target::stop): Pass
target down.
* record-full.c (record_full_wait_1): Switch to event thread.
Pass target down.
* regcache.c (regcache::regcache)
(get_thread_arch_aspace_regcache, get_thread_arch_regcache): Add
process_stratum_target parameter and handle it.
(current_thread_target): New global.
(get_thread_regcache): Add process_stratum_target parameter and
handle it. Switch inferior before calling target method.
(get_thread_regcache): Pass target down.
(get_thread_regcache_for_ptid): Pass target down.
(registers_changed_ptid): Add process_stratum_target parameter and
handle it.
(registers_changed_thread, registers_changed): Pass target down.
(test_get_thread_arch_aspace_regcache): New.
(current_regcache_test): Define a couple local test_target_ops
instances and use them for testing.
(readwrite_regcache): Pass process_stratum_target parameter.
(cooked_read_test, cooked_write_test): Pass mock_target down.
* regcache.h (get_thread_regcache, get_thread_arch_regcache)
(get_thread_arch_aspace_regcache): Add process_stratum_target
parameter.
(regcache::target): New method.
(regcache::regcache, regcache::get_thread_arch_aspace_regcache)
(regcache::registers_changed_ptid): Add process_stratum_target
parameter.
(regcache::m_target): New field.
(registers_changed_ptid): Add process_stratum_target parameter.
* remote.c (remote_state::supports_vCont_probed): New field.
(remote_target::async_wait_fd): New method.
(remote_unpush_and_throw): Add remote_target parameter.
(get_current_remote_target): Adjust.
(remote_target::remote_add_inferior): Push target.
(remote_target::remote_add_thread)
(remote_target::remote_notice_new_inferior)
(get_remote_thread_info): Pass target down.
(remote_target::update_thread_list): Skip threads of inferiors
bound to other targets. (remote_target::close): Don't discard
inferiors. (remote_target::add_current_inferior_and_thread)
(remote_target::process_initial_stop_replies)
(remote_target::start_remote)
(remote_target::remote_serial_quit_handler): Pass down target.
(remote_target::remote_unpush_target): New remote_target
parameter. Unpush the target from all inferiors.
(remote_target::remote_unpush_and_throw): New remote_target
parameter. Pass it down.
(remote_target::open_1): Check whether the current inferior has
execution instead of checking whether any inferior is live. Pass
target down.
(remote_target::remote_detach_1): Pass down target. Use
remote_unpush_target.
(extended_remote_target::attach): Pass down target.
(remote_target::remote_vcont_probe): Set supports_vCont_probed.
(remote_target::append_resumption): Pass down target.
(remote_target::append_pending_thread_resumptions)
(remote_target::remote_resume_with_hc, remote_target::resume)
(remote_target::commit_resume): Pass down target.
(remote_target::remote_stop_ns): Check supports_vCont_probed.
(remote_target::interrupt_query)
(remote_target::remove_new_fork_children)
(remote_target::check_pending_events_prevent_wildcard_vcont)
(remote_target::remote_parse_stop_reply)
(remote_target::process_stop_reply): Pass down target.
(first_remote_resumed_thread): New remote_target parameter. Pass
it down.
(remote_target::wait_as): Pass down target.
(unpush_and_perror): New remote_target parameter. Pass it down.
(remote_target::readchar, remote_target::remote_serial_write)
(remote_target::getpkt_or_notif_sane_1)
(remote_target::kill_new_fork_children, remote_target::kill): Pass
down target.
(remote_target::mourn_inferior): Pass down target. Use
remote_unpush_target.
(remote_target::core_of_thread)
(remote_target::remote_btrace_maybe_reopen): Pass down target.
(remote_target::pid_to_exec_file)
(remote_target::thread_handle_to_thread_info): Pass down target.
(remote_target::async_wait_fd): New.
* riscv-fbsd-tdep.c: Include "inferior.h".
(riscv_fbsd_get_thread_local_address): Pass down target.
* sol2-tdep.c (sol2_core_pid_to_str): Pass down target.
* sol-thread.c (sol_thread_target::wait, ps_lgetregs, ps_lsetregs)
(ps_lgetfpregs, ps_lsetfpregs, sol_update_thread_list_callback):
Adjust.
* solib-spu.c (spu_skip_standalone_loader): Pass down target.
* solib-svr4.c (enable_break): Pass down target.
* spu-multiarch.c (parse_spufs_run): Pass down target.
* spu-tdep.c (spu2ppu_sniffer): Pass down target.
* target-delegates.c: Regenerate.
* target.c (g_target_stack): Delete.
(current_top_target): Return the current inferior's top target.
(target_has_execution_1): Refer to the passed-in inferior's top
target.
(target_supports_terminal_ours): Check whether the initial
inferior was already created.
(decref_target): New.
(target_stack::push): Incref/decref the target.
(push_target, push_target, unpush_target): Adjust.
(target_stack::unpush): Defref target.
(target_is_pushed): Return bool. Adjust to refer to the current
inferior's target stack.
(dispose_inferior): Delete, and inline parts ...
(target_preopen): ... here. Only dispose of the current inferior.
(target_detach): Hold strong target reference while detaching.
Pass target down.
(target_thread_name): Add assertion.
(target_resume): Pass down target.
(target_ops::beneath, find_target_at): Adjust to refer to the
current inferior's target stack.
(get_dummy_target): New.
(target_pass_ctrlc): Pass the Ctrl-C to the first inferior that
has a thread running.
(initialize_targets): Rename to ...
(_initialize_target): ... this.
* target.h: Include "gdbsupport/refcounted-object.h".
(struct target_ops): Inherit refcounted_object.
(target_ops::shortname, target_ops::longname): Make const.
(target_ops::async_wait_fd): New method.
(decref_target): Declare.
(struct target_ops_ref_policy): New.
(target_ops_ref): New typedef.
(get_dummy_target): Declare function.
(target_is_pushed): Return bool.
* thread-iter.c (all_matching_threads_iterator::m_inf_matches)
(all_matching_threads_iterator::all_matching_threads_iterator):
Handle filter target.
* thread-iter.h (struct all_matching_threads_iterator, struct
all_matching_threads_range, class all_non_exited_threads_range):
Filter by target too. Remove explicit.
* thread.c (threads_executing): Delete.
(inferior_thread): Pass down current inferior.
(clear_thread_inferior_resources): Pass down thread pointer
instead of ptid_t.
(add_thread_silent, add_thread_with_info, add_thread): Add
process_stratum_target parameter. Use it for thread and inferior
searches.
(is_current_thread): New.
(thread_info::deletable): Use it.
(find_thread_ptid, thread_count, in_thread_list)
(thread_change_ptid, set_resumed, set_running): New
process_stratum_target parameter. Pass it down.
(set_executing): New process_stratum_target parameter. Pass it
down. Adjust reference to 'threads_executing'.
(threads_are_executing): New process_stratum_target parameter.
Adjust reference to 'threads_executing'.
(set_stop_requested, finish_thread_state): New
process_stratum_target parameter. Pass it down.
(switch_to_thread): Also match inferior.
(switch_to_thread): New process_stratum_target parameter. Pass it
down.
(update_threads_executing): Reimplement.
* top.c (quit_force): Pop targets from all inferior.
(gdb_init): Don't call initialize_targets.
* windows-nat.c (windows_nat_target) <get_windows_debug_event>:
Declare.
(windows_add_thread, windows_delete_thread): Adjust.
(get_windows_debug_event): Rename to ...
(windows_nat_target::get_windows_debug_event): ... this. Adjust.
* tracefile-tfile.c (tfile_target_open): Pass down target.
* gdbsupport/common-gdbthread.h (struct process_stratum_target):
Forward declare.
(switch_to_thread): Add process_stratum_target parameter.
* mi/mi-interp.c (mi_on_resume_1): Add process_stratum_target
parameter. Use it.
(mi_on_resume): Pass target down.
* nat/fork-inferior.c (startup_inferior): Add
process_stratum_target parameter. Pass it down.
* nat/fork-inferior.h (startup_inferior): Add
process_stratum_target parameter.
* python/py-threadevent.c (py_get_event_thread): Pass target down.
gdb/gdbserver/ChangeLog:
2020-01-10 Pedro Alves <palves@redhat.com>
* fork-child.c (post_fork_inferior): Pass target down to
startup_inferior.
* inferiors.c (switch_to_thread): Add process_stratum_target
parameter.
* lynx-low.c (lynx_target_ops): Now a process_stratum_target.
* nto-low.c (nto_target_ops): Now a process_stratum_target.
* linux-low.c (linux_target_ops): Now a process_stratum_target.
* remote-utils.c (prepare_resume_reply): Pass the target to
switch_to_thread.
* target.c (the_target): Now a process_stratum_target.
(done_accessing_memory): Pass the target to switch_to_thread.
(set_target_ops): Ajust to use process_stratum_target.
* target.h (struct target_ops): Rename to ...
(struct process_stratum_target): ... this.
(the_target, set_target_ops): Adjust.
(prepare_to_access_memory): Adjust comment.
* win32-low.c (child_xfer_memory): Adjust to use
process_stratum_target.
(win32_target_ops): Now a process_stratum_target.
2046 lines
59 KiB
C
2046 lines
59 KiB
C
/* libthread_db assisted debugging support, generic parts.
|
||
|
||
Copyright (C) 1999-2020 Free Software Foundation, Inc.
|
||
|
||
This file is part of GDB.
|
||
|
||
This program is free software; you can redistribute it and/or modify
|
||
it under the terms of the GNU General Public License as published by
|
||
the Free Software Foundation; either version 3 of the License, or
|
||
(at your option) any later version.
|
||
|
||
This program is distributed in the hope that it will be useful,
|
||
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||
GNU General Public License for more details.
|
||
|
||
You should have received a copy of the GNU General Public License
|
||
along with this program. If not, see <http://www.gnu.org/licenses/>. */
|
||
|
||
#include "defs.h"
|
||
#include <dlfcn.h>
|
||
#include "gdb_proc_service.h"
|
||
#include "nat/gdb_thread_db.h"
|
||
#include "gdbsupport/gdb_vecs.h"
|
||
#include "bfd.h"
|
||
#include "command.h"
|
||
#include "gdbcmd.h"
|
||
#include "gdbthread.h"
|
||
#include "inferior.h"
|
||
#include "infrun.h"
|
||
#include "symfile.h"
|
||
#include "objfiles.h"
|
||
#include "target.h"
|
||
#include "regcache.h"
|
||
#include "solib.h"
|
||
#include "solib-svr4.h"
|
||
#include "gdbcore.h"
|
||
#include "observable.h"
|
||
#include "linux-nat.h"
|
||
#include "nat/linux-procfs.h"
|
||
#include "nat/linux-ptrace.h"
|
||
#include "nat/linux-osdata.h"
|
||
#include "auto-load.h"
|
||
#include "cli/cli-utils.h"
|
||
#include <signal.h>
|
||
#include <ctype.h>
|
||
#include "nat/linux-namespaces.h"
|
||
#include <algorithm>
|
||
#include "gdbsupport/pathstuff.h"
|
||
#include "valprint.h"
|
||
#include "cli/cli-style.h"
|
||
|
||
/* GNU/Linux libthread_db support.
|
||
|
||
libthread_db is a library, provided along with libpthread.so, which
|
||
exposes the internals of the thread library to a debugger. It
|
||
allows GDB to find existing threads, new threads as they are
|
||
created, thread IDs (usually, the result of pthread_self), and
|
||
thread-local variables.
|
||
|
||
The libthread_db interface originates on Solaris, where it is both
|
||
more powerful and more complicated. This implementation only works
|
||
for NPTL, the glibc threading library. It assumes that each thread
|
||
is permanently assigned to a single light-weight process (LWP). At
|
||
some point it also supported the older LinuxThreads library, but it
|
||
no longer does.
|
||
|
||
libthread_db-specific information is stored in the "private" field
|
||
of struct thread_info. When the field is NULL we do not yet have
|
||
information about the new thread; this could be temporary (created,
|
||
but the thread library's data structures do not reflect it yet)
|
||
or permanent (created using clone instead of pthread_create).
|
||
|
||
Process IDs managed by linux-thread-db.c match those used by
|
||
linux-nat.c: a common PID for all processes, an LWP ID for each
|
||
thread, and no TID. We save the TID in private. Keeping it out
|
||
of the ptid_t prevents thread IDs changing when libpthread is
|
||
loaded or unloaded. */
|
||
|
||
static const target_info thread_db_target_info = {
|
||
"multi-thread",
|
||
N_("multi-threaded child process."),
|
||
N_("Threads and pthreads support.")
|
||
};
|
||
|
||
class thread_db_target final : public target_ops
|
||
{
|
||
public:
|
||
const target_info &info () const override
|
||
{ return thread_db_target_info; }
|
||
|
||
strata stratum () const override { return thread_stratum; }
|
||
|
||
void detach (inferior *, int) override;
|
||
ptid_t wait (ptid_t, struct target_waitstatus *, int) override;
|
||
void resume (ptid_t, int, enum gdb_signal) override;
|
||
void mourn_inferior () override;
|
||
void update_thread_list () override;
|
||
std::string pid_to_str (ptid_t) override;
|
||
CORE_ADDR get_thread_local_address (ptid_t ptid,
|
||
CORE_ADDR load_module_addr,
|
||
CORE_ADDR offset) override;
|
||
const char *extra_thread_info (struct thread_info *) override;
|
||
ptid_t get_ada_task_ptid (long lwp, long thread) override;
|
||
|
||
thread_info *thread_handle_to_thread_info (const gdb_byte *thread_handle,
|
||
int handle_len,
|
||
inferior *inf) override;
|
||
gdb::byte_vector thread_info_to_thread_handle (struct thread_info *) override;
|
||
};
|
||
|
||
static char *libthread_db_search_path;
|
||
|
||
/* Set to true if thread_db auto-loading is enabled
|
||
by the "set auto-load libthread-db" command. */
|
||
static bool auto_load_thread_db = true;
|
||
|
||
/* Set to true if load-time libthread_db tests have been enabled
|
||
by the "maintenance set check-libthread-db" command. */
|
||
static bool check_thread_db_on_load = false;
|
||
|
||
/* "show" command for the auto_load_thread_db configuration variable. */
|
||
|
||
static void
|
||
show_auto_load_thread_db (struct ui_file *file, int from_tty,
|
||
struct cmd_list_element *c, const char *value)
|
||
{
|
||
fprintf_filtered (file, _("Auto-loading of inferior specific libthread_db "
|
||
"is %s.\n"),
|
||
value);
|
||
}
|
||
|
||
static void
|
||
set_libthread_db_search_path (const char *ignored, int from_tty,
|
||
struct cmd_list_element *c)
|
||
{
|
||
if (*libthread_db_search_path == '\0')
|
||
{
|
||
xfree (libthread_db_search_path);
|
||
libthread_db_search_path = xstrdup (LIBTHREAD_DB_SEARCH_PATH);
|
||
}
|
||
}
|
||
|
||
/* If non-zero, print details of libthread_db processing. */
|
||
|
||
static unsigned int libthread_db_debug;
|
||
|
||
static void
|
||
show_libthread_db_debug (struct ui_file *file, int from_tty,
|
||
struct cmd_list_element *c, const char *value)
|
||
{
|
||
fprintf_filtered (file, _("libthread-db debugging is %s.\n"), value);
|
||
}
|
||
|
||
/* If we're running on GNU/Linux, we must explicitly attach to any new
|
||
threads. */
|
||
|
||
/* This module's target vector. */
|
||
static thread_db_target the_thread_db_target;
|
||
|
||
/* Non-zero if we have determined the signals used by the threads
|
||
library. */
|
||
static int thread_signals;
|
||
static sigset_t thread_stop_set;
|
||
static sigset_t thread_print_set;
|
||
|
||
struct thread_db_info
|
||
{
|
||
struct thread_db_info *next;
|
||
|
||
/* The target this thread_db_info is bound to. */
|
||
process_stratum_target *process_target;
|
||
|
||
/* Process id this object refers to. */
|
||
int pid;
|
||
|
||
/* Handle from dlopen for libthread_db.so. */
|
||
void *handle;
|
||
|
||
/* Absolute pathname from gdb_realpath to disk file used for dlopen-ing
|
||
HANDLE. It may be NULL for system library. */
|
||
char *filename;
|
||
|
||
/* Structure that identifies the child process for the
|
||
<proc_service.h> interface. */
|
||
struct ps_prochandle proc_handle;
|
||
|
||
/* Connection to the libthread_db library. */
|
||
td_thragent_t *thread_agent;
|
||
|
||
/* True if we need to apply the workaround for glibc/BZ5983. When
|
||
we catch a PTRACE_O_TRACEFORK, and go query the child's thread
|
||
list, nptl_db returns the parent's threads in addition to the new
|
||
(single) child thread. If this flag is set, we do extra work to
|
||
be able to ignore such stale entries. */
|
||
int need_stale_parent_threads_check;
|
||
|
||
/* Pointers to the libthread_db functions. */
|
||
|
||
td_init_ftype *td_init_p;
|
||
td_ta_new_ftype *td_ta_new_p;
|
||
td_ta_delete_ftype *td_ta_delete_p;
|
||
td_ta_map_lwp2thr_ftype *td_ta_map_lwp2thr_p;
|
||
td_ta_thr_iter_ftype *td_ta_thr_iter_p;
|
||
td_thr_get_info_ftype *td_thr_get_info_p;
|
||
td_thr_tls_get_addr_ftype *td_thr_tls_get_addr_p;
|
||
td_thr_tlsbase_ftype *td_thr_tlsbase_p;
|
||
};
|
||
|
||
/* List of known processes using thread_db, and the required
|
||
bookkeeping. */
|
||
struct thread_db_info *thread_db_list;
|
||
|
||
static void thread_db_find_new_threads_1 (thread_info *stopped);
|
||
static void thread_db_find_new_threads_2 (thread_info *stopped,
|
||
bool until_no_new);
|
||
|
||
static void check_thread_signals (void);
|
||
|
||
static struct thread_info *record_thread
|
||
(struct thread_db_info *info, struct thread_info *tp,
|
||
ptid_t ptid, const td_thrhandle_t *th_p, const td_thrinfo_t *ti_p);
|
||
|
||
/* Add the current inferior to the list of processes using libpthread.
|
||
Return a pointer to the newly allocated object that was added to
|
||
THREAD_DB_LIST. HANDLE is the handle returned by dlopen'ing
|
||
LIBTHREAD_DB_SO. */
|
||
|
||
static struct thread_db_info *
|
||
add_thread_db_info (void *handle)
|
||
{
|
||
struct thread_db_info *info = XCNEW (struct thread_db_info);
|
||
|
||
info->process_target = current_inferior ()->process_target ();
|
||
info->pid = inferior_ptid.pid ();
|
||
info->handle = handle;
|
||
|
||
/* The workaround works by reading from /proc/pid/status, so it is
|
||
disabled for core files. */
|
||
if (target_has_execution)
|
||
info->need_stale_parent_threads_check = 1;
|
||
|
||
info->next = thread_db_list;
|
||
thread_db_list = info;
|
||
|
||
return info;
|
||
}
|
||
|
||
/* Return the thread_db_info object representing the bookkeeping
|
||
related to process PID, if any; NULL otherwise. */
|
||
|
||
static struct thread_db_info *
|
||
get_thread_db_info (process_stratum_target *targ, int pid)
|
||
{
|
||
struct thread_db_info *info;
|
||
|
||
for (info = thread_db_list; info; info = info->next)
|
||
if (targ == info->process_target && pid == info->pid)
|
||
return info;
|
||
|
||
return NULL;
|
||
}
|
||
|
||
static const char *thread_db_err_str (td_err_e err);
|
||
|
||
/* When PID has exited or has been detached, we no longer want to keep
|
||
track of it as using libpthread. Call this function to discard
|
||
thread_db related info related to PID. Note that this closes
|
||
LIBTHREAD_DB_SO's dlopen'ed handle. */
|
||
|
||
static void
|
||
delete_thread_db_info (process_stratum_target *targ, int pid)
|
||
{
|
||
struct thread_db_info *info, *info_prev;
|
||
|
||
info_prev = NULL;
|
||
|
||
for (info = thread_db_list; info; info_prev = info, info = info->next)
|
||
if (targ == info->process_target && pid == info->pid)
|
||
break;
|
||
|
||
if (info == NULL)
|
||
return;
|
||
|
||
if (info->thread_agent != NULL && info->td_ta_delete_p != NULL)
|
||
{
|
||
td_err_e err = info->td_ta_delete_p (info->thread_agent);
|
||
|
||
if (err != TD_OK)
|
||
warning (_("Cannot deregister process %d from libthread_db: %s"),
|
||
pid, thread_db_err_str (err));
|
||
info->thread_agent = NULL;
|
||
}
|
||
|
||
if (info->handle != NULL)
|
||
dlclose (info->handle);
|
||
|
||
xfree (info->filename);
|
||
|
||
if (info_prev)
|
||
info_prev->next = info->next;
|
||
else
|
||
thread_db_list = info->next;
|
||
|
||
xfree (info);
|
||
}
|
||
|
||
/* Use "struct private_thread_info" to cache thread state. This is
|
||
a substantial optimization. */
|
||
|
||
struct thread_db_thread_info : public private_thread_info
|
||
{
|
||
/* Flag set when we see a TD_DEATH event for this thread. */
|
||
bool dying = false;
|
||
|
||
/* Cached thread state. */
|
||
td_thrhandle_t th {};
|
||
thread_t tid {};
|
||
};
|
||
|
||
static thread_db_thread_info *
|
||
get_thread_db_thread_info (thread_info *thread)
|
||
{
|
||
return static_cast<thread_db_thread_info *> (thread->priv.get ());
|
||
}
|
||
|
||
static const char *
|
||
thread_db_err_str (td_err_e err)
|
||
{
|
||
static char buf[64];
|
||
|
||
switch (err)
|
||
{
|
||
case TD_OK:
|
||
return "generic 'call succeeded'";
|
||
case TD_ERR:
|
||
return "generic error";
|
||
case TD_NOTHR:
|
||
return "no thread to satisfy query";
|
||
case TD_NOSV:
|
||
return "no sync handle to satisfy query";
|
||
case TD_NOLWP:
|
||
return "no LWP to satisfy query";
|
||
case TD_BADPH:
|
||
return "invalid process handle";
|
||
case TD_BADTH:
|
||
return "invalid thread handle";
|
||
case TD_BADSH:
|
||
return "invalid synchronization handle";
|
||
case TD_BADTA:
|
||
return "invalid thread agent";
|
||
case TD_BADKEY:
|
||
return "invalid key";
|
||
case TD_NOMSG:
|
||
return "no event message for getmsg";
|
||
case TD_NOFPREGS:
|
||
return "FPU register set not available";
|
||
case TD_NOLIBTHREAD:
|
||
return "application not linked with libthread";
|
||
case TD_NOEVENT:
|
||
return "requested event is not supported";
|
||
case TD_NOCAPAB:
|
||
return "capability not available";
|
||
case TD_DBERR:
|
||
return "debugger service failed";
|
||
case TD_NOAPLIC:
|
||
return "operation not applicable to";
|
||
case TD_NOTSD:
|
||
return "no thread-specific data for this thread";
|
||
case TD_MALLOC:
|
||
return "malloc failed";
|
||
case TD_PARTIALREG:
|
||
return "only part of register set was written/read";
|
||
case TD_NOXREGS:
|
||
return "X register set not available for this thread";
|
||
#ifdef THREAD_DB_HAS_TD_NOTALLOC
|
||
case TD_NOTALLOC:
|
||
return "thread has not yet allocated TLS for given module";
|
||
#endif
|
||
#ifdef THREAD_DB_HAS_TD_VERSION
|
||
case TD_VERSION:
|
||
return "versions of libpthread and libthread_db do not match";
|
||
#endif
|
||
#ifdef THREAD_DB_HAS_TD_NOTLS
|
||
case TD_NOTLS:
|
||
return "there is no TLS segment in the given module";
|
||
#endif
|
||
default:
|
||
snprintf (buf, sizeof (buf), "unknown thread_db error '%d'", err);
|
||
return buf;
|
||
}
|
||
}
|
||
|
||
/* Fetch the user-level thread id of PTID. STOPPED is a stopped
|
||
thread that we can use to access memory. */
|
||
|
||
static struct thread_info *
|
||
thread_from_lwp (thread_info *stopped, ptid_t ptid)
|
||
{
|
||
td_thrhandle_t th;
|
||
td_thrinfo_t ti;
|
||
td_err_e err;
|
||
struct thread_db_info *info;
|
||
struct thread_info *tp;
|
||
|
||
/* Just in case td_ta_map_lwp2thr doesn't initialize it completely. */
|
||
th.th_unique = 0;
|
||
|
||
/* This ptid comes from linux-nat.c, which should always fill in the
|
||
LWP. */
|
||
gdb_assert (ptid.lwp () != 0);
|
||
|
||
info = get_thread_db_info (stopped->inf->process_target (), ptid.pid ());
|
||
|
||
/* Access an lwp we know is stopped. */
|
||
info->proc_handle.thread = stopped;
|
||
err = info->td_ta_map_lwp2thr_p (info->thread_agent, ptid.lwp (),
|
||
&th);
|
||
if (err != TD_OK)
|
||
error (_("Cannot find user-level thread for LWP %ld: %s"),
|
||
ptid.lwp (), thread_db_err_str (err));
|
||
|
||
err = info->td_thr_get_info_p (&th, &ti);
|
||
if (err != TD_OK)
|
||
error (_("thread_get_info_callback: cannot get thread info: %s"),
|
||
thread_db_err_str (err));
|
||
|
||
/* Fill the cache. */
|
||
tp = find_thread_ptid (stopped->inf->process_target (), ptid);
|
||
return record_thread (info, tp, ptid, &th, &ti);
|
||
}
|
||
|
||
|
||
/* See linux-nat.h. */
|
||
|
||
int
|
||
thread_db_notice_clone (ptid_t parent, ptid_t child)
|
||
{
|
||
struct thread_db_info *info;
|
||
|
||
info = get_thread_db_info (linux_target, child.pid ());
|
||
|
||
if (info == NULL)
|
||
return 0;
|
||
|
||
thread_info *stopped = find_thread_ptid (linux_target, parent);
|
||
|
||
thread_from_lwp (stopped, child);
|
||
|
||
/* If we do not know about the main thread's pthread info yet, this
|
||
would be a good time to find it. */
|
||
thread_from_lwp (stopped, parent);
|
||
return 1;
|
||
}
|
||
|
||
static void *
|
||
verbose_dlsym (void *handle, const char *name)
|
||
{
|
||
void *sym = dlsym (handle, name);
|
||
if (sym == NULL)
|
||
warning (_("Symbol \"%s\" not found in libthread_db: %s"),
|
||
name, dlerror ());
|
||
return sym;
|
||
}
|
||
|
||
/* Verify inferior's '\0'-terminated symbol VER_SYMBOL starts with "%d.%d" and
|
||
return 1 if this version is lower (and not equal) to
|
||
VER_MAJOR_MIN.VER_MINOR_MIN. Return 0 in all other cases. */
|
||
|
||
static int
|
||
inferior_has_bug (const char *ver_symbol, int ver_major_min, int ver_minor_min)
|
||
{
|
||
struct bound_minimal_symbol version_msym;
|
||
CORE_ADDR version_addr;
|
||
gdb::unique_xmalloc_ptr<char> version;
|
||
int err, got, retval = 0;
|
||
|
||
version_msym = lookup_minimal_symbol (ver_symbol, NULL, NULL);
|
||
if (version_msym.minsym == NULL)
|
||
return 0;
|
||
|
||
version_addr = BMSYMBOL_VALUE_ADDRESS (version_msym);
|
||
got = target_read_string (version_addr, &version, 32, &err);
|
||
if (err == 0 && memchr (version.get (), 0, got) == version.get () + got - 1)
|
||
{
|
||
int major, minor;
|
||
|
||
retval = (sscanf (version.get (), "%d.%d", &major, &minor) == 2
|
||
&& (major < ver_major_min
|
||
|| (major == ver_major_min && minor < ver_minor_min)));
|
||
}
|
||
|
||
return retval;
|
||
}
|
||
|
||
/* Similar as thread_db_find_new_threads_1, but try to silently ignore errors
|
||
if appropriate.
|
||
|
||
Return 1 if the caller should abort libthread_db initialization. Return 0
|
||
otherwise. */
|
||
|
||
static int
|
||
thread_db_find_new_threads_silently (thread_info *stopped)
|
||
{
|
||
|
||
try
|
||
{
|
||
thread_db_find_new_threads_2 (stopped, true);
|
||
}
|
||
|
||
catch (const gdb_exception_error &except)
|
||
{
|
||
if (libthread_db_debug)
|
||
exception_fprintf (gdb_stdlog, except,
|
||
"Warning: thread_db_find_new_threads_silently: ");
|
||
|
||
/* There is a bug fixed between nptl 2.6.1 and 2.7 by
|
||
commit 7d9d8bd18906fdd17364f372b160d7ab896ce909
|
||
where calls to td_thr_get_info fail with TD_ERR for statically linked
|
||
executables if td_thr_get_info is called before glibc has initialized
|
||
itself.
|
||
|
||
If the nptl bug is NOT present in the inferior and still thread_db
|
||
reports an error return 1. It means the inferior has corrupted thread
|
||
list and GDB should fall back only to LWPs.
|
||
|
||
If the nptl bug is present in the inferior return 0 to silently ignore
|
||
such errors, and let gdb enumerate threads again later. In such case
|
||
GDB cannot properly display LWPs if the inferior thread list is
|
||
corrupted. For core files it does not apply, no 'later enumeration'
|
||
is possible. */
|
||
|
||
if (!target_has_execution || !inferior_has_bug ("nptl_version", 2, 7))
|
||
{
|
||
exception_fprintf (gdb_stderr, except,
|
||
_("Warning: couldn't activate thread debugging "
|
||
"using libthread_db: "));
|
||
return 1;
|
||
}
|
||
}
|
||
|
||
return 0;
|
||
}
|
||
|
||
/* Lookup a library in which given symbol resides.
|
||
Note: this is looking in GDB process, not in the inferior.
|
||
Returns library name, or NULL. */
|
||
|
||
static const char *
|
||
dladdr_to_soname (const void *addr)
|
||
{
|
||
Dl_info info;
|
||
|
||
if (dladdr (addr, &info) != 0)
|
||
return info.dli_fname;
|
||
return NULL;
|
||
}
|
||
|
||
/* State for check_thread_db_callback. */
|
||
|
||
struct check_thread_db_info
|
||
{
|
||
/* The libthread_db under test. */
|
||
struct thread_db_info *info;
|
||
|
||
/* True if progress should be logged. */
|
||
bool log_progress;
|
||
|
||
/* True if the callback was called. */
|
||
bool threads_seen;
|
||
|
||
/* Name of last libthread_db function called. */
|
||
const char *last_call;
|
||
|
||
/* Value returned by last libthread_db call. */
|
||
td_err_e last_result;
|
||
};
|
||
|
||
static struct check_thread_db_info *tdb_testinfo;
|
||
|
||
/* Callback for check_thread_db. */
|
||
|
||
static int
|
||
check_thread_db_callback (const td_thrhandle_t *th, void *arg)
|
||
{
|
||
gdb_assert (tdb_testinfo != NULL);
|
||
tdb_testinfo->threads_seen = true;
|
||
|
||
#define LOG(fmt, args...) \
|
||
do \
|
||
{ \
|
||
if (tdb_testinfo->log_progress) \
|
||
{ \
|
||
debug_printf (fmt, ## args); \
|
||
gdb_flush (gdb_stdlog); \
|
||
} \
|
||
} \
|
||
while (0)
|
||
|
||
#define CHECK_1(expr, args...) \
|
||
do \
|
||
{ \
|
||
if (!(expr)) \
|
||
{ \
|
||
LOG (" ... FAIL!\n"); \
|
||
error (args); \
|
||
} \
|
||
} \
|
||
while (0)
|
||
|
||
#define CHECK(expr) \
|
||
CHECK_1 (expr, "(%s) == false", #expr)
|
||
|
||
#define CALL_UNCHECKED(func, args...) \
|
||
do \
|
||
{ \
|
||
tdb_testinfo->last_call = #func; \
|
||
tdb_testinfo->last_result \
|
||
= tdb_testinfo->info->func ## _p (args); \
|
||
} \
|
||
while (0)
|
||
|
||
#define CHECK_CALL() \
|
||
CHECK_1 (tdb_testinfo->last_result == TD_OK, \
|
||
_("%s failed: %s"), \
|
||
tdb_testinfo->last_call, \
|
||
thread_db_err_str (tdb_testinfo->last_result)) \
|
||
|
||
#define CALL(func, args...) \
|
||
do \
|
||
{ \
|
||
CALL_UNCHECKED (func, args); \
|
||
CHECK_CALL (); \
|
||
} \
|
||
while (0)
|
||
|
||
LOG (" Got thread");
|
||
|
||
/* Check td_ta_thr_iter passed consistent arguments. */
|
||
CHECK (th != NULL);
|
||
CHECK (arg == (void *) tdb_testinfo);
|
||
CHECK (th->th_ta_p == tdb_testinfo->info->thread_agent);
|
||
|
||
LOG (" %s", core_addr_to_string_nz ((CORE_ADDR) th->th_unique));
|
||
|
||
/* Check td_thr_get_info. */
|
||
td_thrinfo_t ti;
|
||
CALL (td_thr_get_info, th, &ti);
|
||
|
||
LOG (" => %d", ti.ti_lid);
|
||
|
||
CHECK (ti.ti_ta_p == th->th_ta_p);
|
||
CHECK (ti.ti_tid == (thread_t) th->th_unique);
|
||
|
||
/* Check td_ta_map_lwp2thr. */
|
||
td_thrhandle_t th2;
|
||
memset (&th2, 23, sizeof (td_thrhandle_t));
|
||
CALL_UNCHECKED (td_ta_map_lwp2thr, th->th_ta_p, ti.ti_lid, &th2);
|
||
|
||
if (tdb_testinfo->last_result == TD_ERR && !target_has_execution)
|
||
{
|
||
/* Some platforms require execution for td_ta_map_lwp2thr. */
|
||
LOG (_("; can't map_lwp2thr"));
|
||
}
|
||
else
|
||
{
|
||
CHECK_CALL ();
|
||
|
||
LOG (" => %s", core_addr_to_string_nz ((CORE_ADDR) th2.th_unique));
|
||
|
||
CHECK (memcmp (th, &th2, sizeof (td_thrhandle_t)) == 0);
|
||
}
|
||
|
||
/* Attempt TLS access. Assuming errno is TLS, this calls
|
||
thread_db_get_thread_local_address, which in turn calls
|
||
td_thr_tls_get_addr for live inferiors or td_thr_tlsbase
|
||
for core files. This test is skipped if the thread has
|
||
not been recorded; proceeding in that case would result
|
||
in the test having the side-effect of noticing threads
|
||
which seems wrong.
|
||
|
||
Note that in glibc's libthread_db td_thr_tls_get_addr is
|
||
a thin wrapper around td_thr_tlsbase; this check always
|
||
hits the bulk of the code.
|
||
|
||
Note also that we don't actually check any libthread_db
|
||
calls are made, we just assume they were; future changes
|
||
to how GDB accesses TLS could result in this passing
|
||
without exercising the calls it's supposed to. */
|
||
ptid_t ptid = ptid_t (tdb_testinfo->info->pid, ti.ti_lid, 0);
|
||
thread_info *thread_info = find_thread_ptid (linux_target, ptid);
|
||
if (thread_info != NULL && thread_info->priv != NULL)
|
||
{
|
||
LOG ("; errno");
|
||
|
||
scoped_restore_current_thread restore_current_thread;
|
||
switch_to_thread (thread_info);
|
||
|
||
expression_up expr = parse_expression ("(int) errno");
|
||
struct value *val = evaluate_expression (expr.get ());
|
||
|
||
if (tdb_testinfo->log_progress)
|
||
{
|
||
struct value_print_options opts;
|
||
|
||
get_user_print_options (&opts);
|
||
LOG (" = ");
|
||
value_print (val, gdb_stdlog, &opts);
|
||
}
|
||
}
|
||
|
||
LOG (" ... OK\n");
|
||
|
||
#undef LOG
|
||
#undef CHECK_1
|
||
#undef CHECK
|
||
#undef CALL_UNCHECKED
|
||
#undef CHECK_CALL
|
||
#undef CALL
|
||
|
||
return 0;
|
||
}
|
||
|
||
/* Run integrity checks on the dlopen()ed libthread_db described by
|
||
INFO. Returns true on success, displays a warning and returns
|
||
false on failure. Logs progress messages to gdb_stdlog during
|
||
the test if LOG_PROGRESS is true. */
|
||
|
||
static bool
|
||
check_thread_db (struct thread_db_info *info, bool log_progress)
|
||
{
|
||
bool test_passed = true;
|
||
|
||
if (log_progress)
|
||
debug_printf (_("Running libthread_db integrity checks:\n"));
|
||
|
||
/* GDB avoids using td_ta_thr_iter wherever possible (see comment
|
||
in try_thread_db_load_1 below) so in order to test it we may
|
||
have to locate it ourselves. */
|
||
td_ta_thr_iter_ftype *td_ta_thr_iter_p = info->td_ta_thr_iter_p;
|
||
if (td_ta_thr_iter_p == NULL)
|
||
{
|
||
void *thr_iter = verbose_dlsym (info->handle, "td_ta_thr_iter");
|
||
if (thr_iter == NULL)
|
||
return 0;
|
||
|
||
td_ta_thr_iter_p = (td_ta_thr_iter_ftype *) thr_iter;
|
||
}
|
||
|
||
/* Set up the test state we share with the callback. */
|
||
gdb_assert (tdb_testinfo == NULL);
|
||
struct check_thread_db_info tdb_testinfo_buf;
|
||
tdb_testinfo = &tdb_testinfo_buf;
|
||
|
||
memset (tdb_testinfo, 0, sizeof (struct check_thread_db_info));
|
||
tdb_testinfo->info = info;
|
||
tdb_testinfo->log_progress = log_progress;
|
||
|
||
/* td_ta_thr_iter shouldn't be used on running processes. Note that
|
||
it's possible the inferior will stop midway through modifying one
|
||
of its thread lists, in which case the check will spuriously
|
||
fail. */
|
||
linux_stop_and_wait_all_lwps ();
|
||
|
||
try
|
||
{
|
||
td_err_e err = td_ta_thr_iter_p (info->thread_agent,
|
||
check_thread_db_callback,
|
||
tdb_testinfo,
|
||
TD_THR_ANY_STATE,
|
||
TD_THR_LOWEST_PRIORITY,
|
||
TD_SIGNO_MASK,
|
||
TD_THR_ANY_USER_FLAGS);
|
||
|
||
if (err != TD_OK)
|
||
error (_("td_ta_thr_iter failed: %s"), thread_db_err_str (err));
|
||
|
||
if (!tdb_testinfo->threads_seen)
|
||
error (_("no threads seen"));
|
||
}
|
||
catch (const gdb_exception_error &except)
|
||
{
|
||
if (warning_pre_print)
|
||
fputs_unfiltered (warning_pre_print, gdb_stderr);
|
||
|
||
exception_fprintf (gdb_stderr, except,
|
||
_("libthread_db integrity checks failed: "));
|
||
|
||
test_passed = false;
|
||
}
|
||
|
||
if (test_passed && log_progress)
|
||
debug_printf (_("libthread_db integrity checks passed.\n"));
|
||
|
||
tdb_testinfo = NULL;
|
||
|
||
linux_unstop_all_lwps ();
|
||
|
||
return test_passed;
|
||
}
|
||
|
||
/* Attempt to initialize dlopen()ed libthread_db, described by INFO.
|
||
Return true on success.
|
||
Failure could happen if libthread_db does not have symbols we expect,
|
||
or when it refuses to work with the current inferior (e.g. due to
|
||
version mismatch between libthread_db and libpthread). */
|
||
|
||
static bool
|
||
try_thread_db_load_1 (struct thread_db_info *info)
|
||
{
|
||
td_err_e err;
|
||
|
||
/* Initialize pointers to the dynamic library functions we will use.
|
||
Essential functions first. */
|
||
|
||
#define TDB_VERBOSE_DLSYM(info, func) \
|
||
info->func ## _p = (func ## _ftype *) verbose_dlsym (info->handle, #func)
|
||
|
||
#define TDB_DLSYM(info, func) \
|
||
info->func ## _p = (func ## _ftype *) dlsym (info->handle, #func)
|
||
|
||
#define CHK(a) \
|
||
do \
|
||
{ \
|
||
if ((a) == NULL) \
|
||
return false; \
|
||
} while (0)
|
||
|
||
CHK (TDB_VERBOSE_DLSYM (info, td_init));
|
||
|
||
err = info->td_init_p ();
|
||
if (err != TD_OK)
|
||
{
|
||
warning (_("Cannot initialize libthread_db: %s"),
|
||
thread_db_err_str (err));
|
||
return false;
|
||
}
|
||
|
||
CHK (TDB_VERBOSE_DLSYM (info, td_ta_new));
|
||
|
||
/* Initialize the structure that identifies the child process. */
|
||
info->proc_handle.thread = inferior_thread ();
|
||
|
||
/* Now attempt to open a connection to the thread library. */
|
||
err = info->td_ta_new_p (&info->proc_handle, &info->thread_agent);
|
||
if (err != TD_OK)
|
||
{
|
||
if (libthread_db_debug)
|
||
fprintf_unfiltered (gdb_stdlog, _("td_ta_new failed: %s\n"),
|
||
thread_db_err_str (err));
|
||
else
|
||
switch (err)
|
||
{
|
||
case TD_NOLIBTHREAD:
|
||
#ifdef THREAD_DB_HAS_TD_VERSION
|
||
case TD_VERSION:
|
||
#endif
|
||
/* The errors above are not unexpected and silently ignored:
|
||
they just mean we haven't found correct version of
|
||
libthread_db yet. */
|
||
break;
|
||
default:
|
||
warning (_("td_ta_new failed: %s"), thread_db_err_str (err));
|
||
}
|
||
return false;
|
||
}
|
||
|
||
/* These are essential. */
|
||
CHK (TDB_VERBOSE_DLSYM (info, td_ta_map_lwp2thr));
|
||
CHK (TDB_VERBOSE_DLSYM (info, td_thr_get_info));
|
||
|
||
/* These are not essential. */
|
||
TDB_DLSYM (info, td_thr_tls_get_addr);
|
||
TDB_DLSYM (info, td_thr_tlsbase);
|
||
TDB_DLSYM (info, td_ta_delete);
|
||
|
||
/* It's best to avoid td_ta_thr_iter if possible. That walks data
|
||
structures in the inferior's address space that may be corrupted,
|
||
or, if the target is running, may change while we walk them. If
|
||
there's execution (and /proc is mounted), then we're already
|
||
attached to all LWPs. Use thread_from_lwp, which uses
|
||
td_ta_map_lwp2thr instead, which does not walk the thread list.
|
||
|
||
td_ta_map_lwp2thr uses ps_get_thread_area, but we can't use that
|
||
currently on core targets, as it uses ptrace directly. */
|
||
if (target_has_execution
|
||
&& linux_proc_task_list_dir_exists (inferior_ptid.pid ()))
|
||
info->td_ta_thr_iter_p = NULL;
|
||
else
|
||
CHK (TDB_VERBOSE_DLSYM (info, td_ta_thr_iter));
|
||
|
||
#undef TDB_VERBOSE_DLSYM
|
||
#undef TDB_DLSYM
|
||
#undef CHK
|
||
|
||
/* Run integrity checks if requested. */
|
||
if (check_thread_db_on_load)
|
||
{
|
||
if (!check_thread_db (info, libthread_db_debug))
|
||
return false;
|
||
}
|
||
|
||
if (info->td_ta_thr_iter_p == NULL)
|
||
{
|
||
struct lwp_info *lp;
|
||
int pid = inferior_ptid.pid ();
|
||
thread_info *curr_thread = inferior_thread ();
|
||
|
||
linux_stop_and_wait_all_lwps ();
|
||
|
||
ALL_LWPS (lp)
|
||
if (lp->ptid.pid () == pid)
|
||
thread_from_lwp (curr_thread, lp->ptid);
|
||
|
||
linux_unstop_all_lwps ();
|
||
}
|
||
else if (thread_db_find_new_threads_silently (inferior_thread ()) != 0)
|
||
{
|
||
/* Even if libthread_db initializes, if the thread list is
|
||
corrupted, we'd not manage to list any threads. Better reject this
|
||
thread_db, and fall back to at least listing LWPs. */
|
||
return false;
|
||
}
|
||
|
||
printf_unfiltered (_("[Thread debugging using libthread_db enabled]\n"));
|
||
|
||
if (*libthread_db_search_path || libthread_db_debug)
|
||
{
|
||
struct ui_file *file;
|
||
const char *library;
|
||
|
||
library = dladdr_to_soname ((const void *) *info->td_ta_new_p);
|
||
if (library == NULL)
|
||
library = LIBTHREAD_DB_SO;
|
||
|
||
/* If we'd print this to gdb_stdout when debug output is
|
||
disabled, still print it to gdb_stdout if debug output is
|
||
enabled. User visible output should not depend on debug
|
||
settings. */
|
||
file = *libthread_db_search_path != '\0' ? gdb_stdout : gdb_stdlog;
|
||
fprintf_unfiltered (file,
|
||
_("Using host libthread_db library \"%ps\".\n"),
|
||
styled_string (file_name_style.style (), library));
|
||
}
|
||
|
||
/* The thread library was detected. Activate the thread_db target
|
||
for this process. */
|
||
push_target (&the_thread_db_target);
|
||
return true;
|
||
}
|
||
|
||
/* Attempt to use LIBRARY as libthread_db. LIBRARY could be absolute,
|
||
relative, or just LIBTHREAD_DB. */
|
||
|
||
static bool
|
||
try_thread_db_load (const char *library, bool check_auto_load_safe)
|
||
{
|
||
void *handle;
|
||
struct thread_db_info *info;
|
||
|
||
if (libthread_db_debug)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
_("Trying host libthread_db library: %s.\n"),
|
||
library);
|
||
|
||
if (check_auto_load_safe)
|
||
{
|
||
if (access (library, R_OK) != 0)
|
||
{
|
||
/* Do not print warnings by file_is_auto_load_safe if the library does
|
||
not exist at this place. */
|
||
if (libthread_db_debug)
|
||
fprintf_unfiltered (gdb_stdlog, _("open failed: %s.\n"),
|
||
safe_strerror (errno));
|
||
return false;
|
||
}
|
||
|
||
if (!file_is_auto_load_safe (library, _("auto-load: Loading libthread-db "
|
||
"library \"%s\" from explicit "
|
||
"directory.\n"),
|
||
library))
|
||
return false;
|
||
}
|
||
|
||
handle = dlopen (library, RTLD_NOW);
|
||
if (handle == NULL)
|
||
{
|
||
if (libthread_db_debug)
|
||
fprintf_unfiltered (gdb_stdlog, _("dlopen failed: %s.\n"), dlerror ());
|
||
return false;
|
||
}
|
||
|
||
if (libthread_db_debug && strchr (library, '/') == NULL)
|
||
{
|
||
void *td_init;
|
||
|
||
td_init = dlsym (handle, "td_init");
|
||
if (td_init != NULL)
|
||
{
|
||
const char *const libpath = dladdr_to_soname (td_init);
|
||
|
||
if (libpath != NULL)
|
||
fprintf_unfiltered (gdb_stdlog, _("Host %s resolved to: %s.\n"),
|
||
library, libpath);
|
||
}
|
||
}
|
||
|
||
info = add_thread_db_info (handle);
|
||
|
||
/* Do not save system library name, that one is always trusted. */
|
||
if (strchr (library, '/') != NULL)
|
||
info->filename = gdb_realpath (library).release ();
|
||
|
||
if (try_thread_db_load_1 (info))
|
||
return true;
|
||
|
||
/* This library "refused" to work on current inferior. */
|
||
delete_thread_db_info (current_inferior ()->process_target (),
|
||
inferior_ptid.pid ());
|
||
return false;
|
||
}
|
||
|
||
/* Subroutine of try_thread_db_load_from_pdir to simplify it.
|
||
Try loading libthread_db in directory(OBJ)/SUBDIR.
|
||
SUBDIR may be NULL. It may also be something like "../lib64".
|
||
The result is true for success. */
|
||
|
||
static bool
|
||
try_thread_db_load_from_pdir_1 (struct objfile *obj, const char *subdir)
|
||
{
|
||
const char *obj_name = objfile_name (obj);
|
||
|
||
if (obj_name[0] != '/')
|
||
{
|
||
warning (_("Expected absolute pathname for libpthread in the"
|
||
" inferior, but got %ps."),
|
||
styled_string (file_name_style.style (), obj_name));
|
||
return false;
|
||
}
|
||
|
||
std::string path = obj_name;
|
||
size_t cp = path.rfind ('/');
|
||
/* This should at minimum hit the first character. */
|
||
gdb_assert (cp != std::string::npos);
|
||
path.resize (cp + 1);
|
||
if (subdir != NULL)
|
||
path = path + subdir + "/";
|
||
path += LIBTHREAD_DB_SO;
|
||
|
||
return try_thread_db_load (path.c_str (), true);
|
||
}
|
||
|
||
/* Handle $pdir in libthread-db-search-path.
|
||
Look for libthread_db in directory(libpthread)/SUBDIR.
|
||
SUBDIR may be NULL. It may also be something like "../lib64".
|
||
The result is true for success. */
|
||
|
||
static bool
|
||
try_thread_db_load_from_pdir (const char *subdir)
|
||
{
|
||
if (!auto_load_thread_db)
|
||
return false;
|
||
|
||
for (objfile *obj : current_program_space->objfiles ())
|
||
if (libpthread_name_p (objfile_name (obj)))
|
||
{
|
||
if (try_thread_db_load_from_pdir_1 (obj, subdir))
|
||
return true;
|
||
|
||
/* We may have found the separate-debug-info version of
|
||
libpthread, and it may live in a directory without a matching
|
||
libthread_db. */
|
||
if (obj->separate_debug_objfile_backlink != NULL)
|
||
return try_thread_db_load_from_pdir_1 (obj->separate_debug_objfile_backlink,
|
||
subdir);
|
||
|
||
return false;
|
||
}
|
||
|
||
return false;
|
||
}
|
||
|
||
/* Handle $sdir in libthread-db-search-path.
|
||
Look for libthread_db in the system dirs, or wherever a plain
|
||
dlopen(file_without_path) will look.
|
||
The result is true for success. */
|
||
|
||
static bool
|
||
try_thread_db_load_from_sdir (void)
|
||
{
|
||
return try_thread_db_load (LIBTHREAD_DB_SO, false);
|
||
}
|
||
|
||
/* Try to load libthread_db from directory DIR of length DIR_LEN.
|
||
The result is true for success. */
|
||
|
||
static bool
|
||
try_thread_db_load_from_dir (const char *dir, size_t dir_len)
|
||
{
|
||
if (!auto_load_thread_db)
|
||
return false;
|
||
|
||
std::string path = std::string (dir, dir_len) + "/" + LIBTHREAD_DB_SO;
|
||
|
||
return try_thread_db_load (path.c_str (), true);
|
||
}
|
||
|
||
/* Search libthread_db_search_path for libthread_db which "agrees"
|
||
to work on current inferior.
|
||
The result is true for success. */
|
||
|
||
static bool
|
||
thread_db_load_search (void)
|
||
{
|
||
bool rc = false;
|
||
|
||
std::vector<gdb::unique_xmalloc_ptr<char>> dir_vec
|
||
= dirnames_to_char_ptr_vec (libthread_db_search_path);
|
||
|
||
for (const gdb::unique_xmalloc_ptr<char> &this_dir_up : dir_vec)
|
||
{
|
||
const char *this_dir = this_dir_up.get ();
|
||
const int pdir_len = sizeof ("$pdir") - 1;
|
||
size_t this_dir_len;
|
||
|
||
this_dir_len = strlen (this_dir);
|
||
|
||
if (strncmp (this_dir, "$pdir", pdir_len) == 0
|
||
&& (this_dir[pdir_len] == '\0'
|
||
|| this_dir[pdir_len] == '/'))
|
||
{
|
||
const char *subdir = NULL;
|
||
|
||
std::string subdir_holder;
|
||
if (this_dir[pdir_len] == '/')
|
||
{
|
||
subdir_holder = std::string (this_dir + pdir_len + 1);
|
||
subdir = subdir_holder.c_str ();
|
||
}
|
||
rc = try_thread_db_load_from_pdir (subdir);
|
||
if (rc)
|
||
break;
|
||
}
|
||
else if (strcmp (this_dir, "$sdir") == 0)
|
||
{
|
||
if (try_thread_db_load_from_sdir ())
|
||
{
|
||
rc = 1;
|
||
break;
|
||
}
|
||
}
|
||
else
|
||
{
|
||
if (try_thread_db_load_from_dir (this_dir, this_dir_len))
|
||
{
|
||
rc = 1;
|
||
break;
|
||
}
|
||
}
|
||
}
|
||
|
||
if (libthread_db_debug)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
_("thread_db_load_search returning %d\n"), rc);
|
||
return rc;
|
||
}
|
||
|
||
/* Return true if the inferior has a libpthread. */
|
||
|
||
static bool
|
||
has_libpthread (void)
|
||
{
|
||
for (objfile *obj : current_program_space->objfiles ())
|
||
if (libpthread_name_p (objfile_name (obj)))
|
||
return true;
|
||
|
||
return false;
|
||
}
|
||
|
||
/* Attempt to load and initialize libthread_db.
|
||
Return 1 on success. */
|
||
|
||
static bool
|
||
thread_db_load (void)
|
||
{
|
||
struct thread_db_info *info;
|
||
|
||
info = get_thread_db_info (current_inferior ()->process_target (),
|
||
inferior_ptid.pid ());
|
||
|
||
if (info != NULL)
|
||
return true;
|
||
|
||
/* Don't attempt to use thread_db on executables not running
|
||
yet. */
|
||
if (!target_has_registers)
|
||
return false;
|
||
|
||
/* Don't attempt to use thread_db for remote targets. */
|
||
if (!(target_can_run () || core_bfd))
|
||
return false;
|
||
|
||
if (thread_db_load_search ())
|
||
return true;
|
||
|
||
/* We couldn't find a libthread_db.
|
||
If the inferior has a libpthread warn the user. */
|
||
if (has_libpthread ())
|
||
{
|
||
warning (_("Unable to find libthread_db matching inferior's thread"
|
||
" library, thread debugging will not be available."));
|
||
return false;
|
||
}
|
||
|
||
/* Either this executable isn't using libpthread at all, or it is
|
||
statically linked. Since we can't easily distinguish these two cases,
|
||
no warning is issued. */
|
||
return false;
|
||
}
|
||
|
||
static void
|
||
check_thread_signals (void)
|
||
{
|
||
if (!thread_signals)
|
||
{
|
||
sigset_t mask;
|
||
int i;
|
||
|
||
lin_thread_get_thread_signals (&mask);
|
||
sigemptyset (&thread_stop_set);
|
||
sigemptyset (&thread_print_set);
|
||
|
||
for (i = 1; i < NSIG; i++)
|
||
{
|
||
if (sigismember (&mask, i))
|
||
{
|
||
if (signal_stop_update (gdb_signal_from_host (i), 0))
|
||
sigaddset (&thread_stop_set, i);
|
||
if (signal_print_update (gdb_signal_from_host (i), 0))
|
||
sigaddset (&thread_print_set, i);
|
||
thread_signals = 1;
|
||
}
|
||
}
|
||
}
|
||
}
|
||
|
||
/* Check whether thread_db is usable. This function is called when
|
||
an inferior is created (or otherwise acquired, e.g. attached to)
|
||
and when new shared libraries are loaded into a running process. */
|
||
|
||
void
|
||
check_for_thread_db (void)
|
||
{
|
||
/* Do nothing if we couldn't load libthread_db.so.1. */
|
||
if (!thread_db_load ())
|
||
return;
|
||
}
|
||
|
||
/* This function is called via the new_objfile observer. */
|
||
|
||
static void
|
||
thread_db_new_objfile (struct objfile *objfile)
|
||
{
|
||
/* This observer must always be called with inferior_ptid set
|
||
correctly. */
|
||
|
||
if (objfile != NULL
|
||
/* libpthread with separate debug info has its debug info file already
|
||
loaded (and notified without successful thread_db initialization)
|
||
the time gdb::observers::new_objfile.notify is called for the library itself.
|
||
Static executables have their separate debug info loaded already
|
||
before the inferior has started. */
|
||
&& objfile->separate_debug_objfile_backlink == NULL
|
||
/* Only check for thread_db if we loaded libpthread,
|
||
or if this is the main symbol file.
|
||
We need to check OBJF_MAINLINE to handle the case of debugging
|
||
a statically linked executable AND the symbol file is specified AFTER
|
||
the exec file is loaded (e.g., gdb -c core ; file foo).
|
||
For dynamically linked executables, libpthread can be near the end
|
||
of the list of shared libraries to load, and in an app of several
|
||
thousand shared libraries, this can otherwise be painful. */
|
||
&& ((objfile->flags & OBJF_MAINLINE) != 0
|
||
|| libpthread_name_p (objfile_name (objfile))))
|
||
check_for_thread_db ();
|
||
}
|
||
|
||
static void
|
||
check_pid_namespace_match (void)
|
||
{
|
||
/* Check is only relevant for local targets targets. */
|
||
if (target_can_run ())
|
||
{
|
||
/* If the child is in a different PID namespace, its idea of its
|
||
PID will differ from our idea of its PID. When we scan the
|
||
child's thread list, we'll mistakenly think it has no threads
|
||
since the thread PID fields won't match the PID we give to
|
||
libthread_db. */
|
||
if (!linux_ns_same (inferior_ptid.pid (), LINUX_NS_PID))
|
||
{
|
||
warning (_ ("Target and debugger are in different PID "
|
||
"namespaces; thread lists and other data are "
|
||
"likely unreliable. "
|
||
"Connect to gdbserver inside the container."));
|
||
}
|
||
}
|
||
}
|
||
|
||
/* This function is called via the inferior_created observer.
|
||
This handles the case of debugging statically linked executables. */
|
||
|
||
static void
|
||
thread_db_inferior_created (struct target_ops *target, int from_tty)
|
||
{
|
||
check_pid_namespace_match ();
|
||
check_for_thread_db ();
|
||
}
|
||
|
||
/* Update the thread's state (what's displayed in "info threads"),
|
||
from libthread_db thread state information. */
|
||
|
||
static void
|
||
update_thread_state (thread_db_thread_info *priv,
|
||
const td_thrinfo_t *ti_p)
|
||
{
|
||
priv->dying = (ti_p->ti_state == TD_THR_UNKNOWN
|
||
|| ti_p->ti_state == TD_THR_ZOMBIE);
|
||
}
|
||
|
||
/* Record a new thread in GDB's thread list. Creates the thread's
|
||
private info. If TP is NULL or TP is marked as having exited,
|
||
creates a new thread. Otherwise, uses TP. */
|
||
|
||
static struct thread_info *
|
||
record_thread (struct thread_db_info *info,
|
||
struct thread_info *tp,
|
||
ptid_t ptid, const td_thrhandle_t *th_p,
|
||
const td_thrinfo_t *ti_p)
|
||
{
|
||
/* A thread ID of zero may mean the thread library has not
|
||
initialized yet. Leave private == NULL until the thread library
|
||
has initialized. */
|
||
if (ti_p->ti_tid == 0)
|
||
return tp;
|
||
|
||
/* Construct the thread's private data. */
|
||
thread_db_thread_info *priv = new thread_db_thread_info;
|
||
|
||
priv->th = *th_p;
|
||
priv->tid = ti_p->ti_tid;
|
||
update_thread_state (priv, ti_p);
|
||
|
||
/* Add the thread to GDB's thread list. If we already know about a
|
||
thread with this PTID, but it's marked exited, then the kernel
|
||
reused the tid of an old thread. */
|
||
if (tp == NULL || tp->state == THREAD_EXITED)
|
||
tp = add_thread_with_info (info->process_target, ptid, priv);
|
||
else
|
||
tp->priv.reset (priv);
|
||
|
||
if (target_has_execution)
|
||
check_thread_signals ();
|
||
|
||
return tp;
|
||
}
|
||
|
||
void
|
||
thread_db_target::detach (inferior *inf, int from_tty)
|
||
{
|
||
delete_thread_db_info (inf->process_target (), inf->pid);
|
||
|
||
beneath ()->detach (inf, from_tty);
|
||
|
||
/* NOTE: From this point on, inferior_ptid is null_ptid. */
|
||
|
||
/* Detach the thread_db target from this inferior. */
|
||
unpush_target (this);
|
||
}
|
||
|
||
ptid_t
|
||
thread_db_target::wait (ptid_t ptid, struct target_waitstatus *ourstatus,
|
||
int options)
|
||
{
|
||
struct thread_db_info *info;
|
||
|
||
process_stratum_target *beneath
|
||
= as_process_stratum_target (this->beneath ());
|
||
|
||
ptid = beneath->wait (ptid, ourstatus, options);
|
||
|
||
switch (ourstatus->kind)
|
||
{
|
||
case TARGET_WAITKIND_IGNORE:
|
||
case TARGET_WAITKIND_EXITED:
|
||
case TARGET_WAITKIND_THREAD_EXITED:
|
||
case TARGET_WAITKIND_SIGNALLED:
|
||
return ptid;
|
||
}
|
||
|
||
info = get_thread_db_info (beneath, ptid.pid ());
|
||
|
||
/* If this process isn't using thread_db, we're done. */
|
||
if (info == NULL)
|
||
return ptid;
|
||
|
||
if (ourstatus->kind == TARGET_WAITKIND_EXECD)
|
||
{
|
||
/* New image, it may or may not end up using thread_db. Assume
|
||
not unless we find otherwise. */
|
||
delete_thread_db_info (beneath, ptid.pid ());
|
||
unpush_target (this);
|
||
|
||
return ptid;
|
||
}
|
||
|
||
/* Fill in the thread's user-level thread id and status. */
|
||
thread_from_lwp (find_thread_ptid (beneath, ptid), ptid);
|
||
|
||
return ptid;
|
||
}
|
||
|
||
void
|
||
thread_db_target::mourn_inferior ()
|
||
{
|
||
process_stratum_target *target_beneath
|
||
= as_process_stratum_target (this->beneath ());
|
||
|
||
delete_thread_db_info (target_beneath, inferior_ptid.pid ());
|
||
|
||
target_beneath->mourn_inferior ();
|
||
|
||
/* Detach the thread_db target from this inferior. */
|
||
unpush_target (this);
|
||
}
|
||
|
||
struct callback_data
|
||
{
|
||
struct thread_db_info *info;
|
||
int new_threads;
|
||
};
|
||
|
||
static int
|
||
find_new_threads_callback (const td_thrhandle_t *th_p, void *data)
|
||
{
|
||
td_thrinfo_t ti;
|
||
td_err_e err;
|
||
struct thread_info *tp;
|
||
struct callback_data *cb_data = (struct callback_data *) data;
|
||
struct thread_db_info *info = cb_data->info;
|
||
|
||
err = info->td_thr_get_info_p (th_p, &ti);
|
||
if (err != TD_OK)
|
||
error (_("find_new_threads_callback: cannot get thread info: %s"),
|
||
thread_db_err_str (err));
|
||
|
||
if (ti.ti_lid == -1)
|
||
{
|
||
/* A thread with kernel thread ID -1 is either a thread that
|
||
exited and was joined, or a thread that is being created but
|
||
hasn't started yet, and that is reusing the tcb/stack of a
|
||
thread that previously exited and was joined. (glibc marks
|
||
terminated and joined threads with kernel thread ID -1. See
|
||
glibc PR17707. */
|
||
if (libthread_db_debug)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"thread_db: skipping exited and "
|
||
"joined thread (0x%lx)\n",
|
||
(unsigned long) ti.ti_tid);
|
||
return 0;
|
||
}
|
||
|
||
if (ti.ti_tid == 0)
|
||
{
|
||
/* A thread ID of zero means that this is the main thread, but
|
||
glibc has not yet initialized thread-local storage and the
|
||
pthread library. We do not know what the thread's TID will
|
||
be yet. */
|
||
|
||
/* In that case, we're not stopped in a fork syscall and don't
|
||
need this glibc bug workaround. */
|
||
info->need_stale_parent_threads_check = 0;
|
||
|
||
return 0;
|
||
}
|
||
|
||
/* Ignore stale parent threads, caused by glibc/BZ5983. This is a
|
||
bit expensive, as it needs to open /proc/pid/status, so try to
|
||
avoid doing the work if we know we don't have to. */
|
||
if (info->need_stale_parent_threads_check)
|
||
{
|
||
int tgid = linux_proc_get_tgid (ti.ti_lid);
|
||
|
||
if (tgid != -1 && tgid != info->pid)
|
||
return 0;
|
||
}
|
||
|
||
ptid_t ptid (info->pid, ti.ti_lid);
|
||
tp = find_thread_ptid (info->process_target, ptid);
|
||
if (tp == NULL || tp->priv == NULL)
|
||
record_thread (info, tp, ptid, th_p, &ti);
|
||
|
||
return 0;
|
||
}
|
||
|
||
/* Helper for thread_db_find_new_threads_2.
|
||
Returns number of new threads found. */
|
||
|
||
static int
|
||
find_new_threads_once (struct thread_db_info *info, int iteration,
|
||
td_err_e *errp)
|
||
{
|
||
struct callback_data data;
|
||
td_err_e err = TD_ERR;
|
||
|
||
data.info = info;
|
||
data.new_threads = 0;
|
||
|
||
/* See comment in thread_db_update_thread_list. */
|
||
gdb_assert (info->td_ta_thr_iter_p != NULL);
|
||
|
||
try
|
||
{
|
||
/* Iterate over all user-space threads to discover new threads. */
|
||
err = info->td_ta_thr_iter_p (info->thread_agent,
|
||
find_new_threads_callback,
|
||
&data,
|
||
TD_THR_ANY_STATE,
|
||
TD_THR_LOWEST_PRIORITY,
|
||
TD_SIGNO_MASK,
|
||
TD_THR_ANY_USER_FLAGS);
|
||
}
|
||
catch (const gdb_exception_error &except)
|
||
{
|
||
if (libthread_db_debug)
|
||
{
|
||
exception_fprintf (gdb_stdlog, except,
|
||
"Warning: find_new_threads_once: ");
|
||
}
|
||
}
|
||
|
||
if (libthread_db_debug)
|
||
{
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
_("Found %d new threads in iteration %d.\n"),
|
||
data.new_threads, iteration);
|
||
}
|
||
|
||
if (errp != NULL)
|
||
*errp = err;
|
||
|
||
return data.new_threads;
|
||
}
|
||
|
||
/* Search for new threads, accessing memory through stopped thread
|
||
PTID. If UNTIL_NO_NEW is true, repeat searching until several
|
||
searches in a row do not discover any new threads. */
|
||
|
||
static void
|
||
thread_db_find_new_threads_2 (thread_info *stopped, bool until_no_new)
|
||
{
|
||
td_err_e err = TD_OK;
|
||
struct thread_db_info *info;
|
||
int i, loop;
|
||
|
||
info = get_thread_db_info (stopped->inf->process_target (),
|
||
stopped->ptid.pid ());
|
||
|
||
/* Access an lwp we know is stopped. */
|
||
info->proc_handle.thread = stopped;
|
||
|
||
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. */
|
||
for (i = 0, loop = 0; loop < 4 && err == TD_OK; ++i, ++loop)
|
||
if (find_new_threads_once (info, i, &err) != 0)
|
||
{
|
||
/* Found some new threads. Restart the loop from beginning. */
|
||
loop = -1;
|
||
}
|
||
}
|
||
else
|
||
find_new_threads_once (info, 0, &err);
|
||
|
||
if (err != TD_OK)
|
||
error (_("Cannot find new threads: %s"), thread_db_err_str (err));
|
||
}
|
||
|
||
static void
|
||
thread_db_find_new_threads_1 (thread_info *stopped)
|
||
{
|
||
thread_db_find_new_threads_2 (stopped, 0);
|
||
}
|
||
|
||
/* Implement the to_update_thread_list target method for this
|
||
target. */
|
||
|
||
void
|
||
thread_db_target::update_thread_list ()
|
||
{
|
||
struct thread_db_info *info;
|
||
|
||
prune_threads ();
|
||
|
||
for (inferior *inf : all_inferiors ())
|
||
{
|
||
if (inf->pid == 0)
|
||
continue;
|
||
|
||
info = get_thread_db_info (inf->process_target (), inf->pid);
|
||
if (info == NULL)
|
||
continue;
|
||
|
||
thread_info *thread = any_live_thread_of_inferior (inf);
|
||
if (thread == NULL || thread->executing)
|
||
continue;
|
||
|
||
/* It's best to avoid td_ta_thr_iter if possible. That walks
|
||
data structures in the inferior's address space that may be
|
||
corrupted, or, if the target is running, the list may change
|
||
while we walk it. In the latter case, it's possible that a
|
||
thread exits just at the exact time that causes GDB to get
|
||
stuck in an infinite loop. To avoid pausing all threads
|
||
whenever the core wants to refresh the thread list, we
|
||
instead use thread_from_lwp immediately when we see an LWP
|
||
stop. That uses thread_db entry points that do not walk
|
||
libpthread's thread list, so should be safe, as well as more
|
||
efficient. */
|
||
if (thread->inf->has_execution ())
|
||
continue;
|
||
|
||
thread_db_find_new_threads_1 (thread);
|
||
}
|
||
|
||
/* Give the beneath target a chance to do extra processing. */
|
||
this->beneath ()->update_thread_list ();
|
||
}
|
||
|
||
std::string
|
||
thread_db_target::pid_to_str (ptid_t ptid)
|
||
{
|
||
thread_info *thread_info = find_thread_ptid (current_inferior (), ptid);
|
||
|
||
if (thread_info != NULL && thread_info->priv != NULL)
|
||
{
|
||
thread_db_thread_info *priv = get_thread_db_thread_info (thread_info);
|
||
|
||
return string_printf ("Thread 0x%lx (LWP %ld)",
|
||
(unsigned long) priv->tid, ptid.lwp ());
|
||
}
|
||
|
||
return beneath ()->pid_to_str (ptid);
|
||
}
|
||
|
||
/* Return a string describing the state of the thread specified by
|
||
INFO. */
|
||
|
||
const char *
|
||
thread_db_target::extra_thread_info (thread_info *info)
|
||
{
|
||
if (info->priv == NULL)
|
||
return NULL;
|
||
|
||
thread_db_thread_info *priv = get_thread_db_thread_info (info);
|
||
|
||
if (priv->dying)
|
||
return "Exiting";
|
||
|
||
return NULL;
|
||
}
|
||
|
||
/* Return pointer to the thread_info struct which corresponds to
|
||
THREAD_HANDLE (having length HANDLE_LEN). */
|
||
|
||
thread_info *
|
||
thread_db_target::thread_handle_to_thread_info (const gdb_byte *thread_handle,
|
||
int handle_len,
|
||
inferior *inf)
|
||
{
|
||
thread_t handle_tid;
|
||
|
||
/* When debugging a 32-bit target from a 64-bit host, handle_len
|
||
will be 4 and sizeof (handle_tid) will be 8. This requires
|
||
a different cast than the more straightforward case where
|
||
the sizes are the same.
|
||
|
||
Use "--target_board unix/-m32" from a native x86_64 linux build
|
||
to test the 32/64-bit case. */
|
||
if (handle_len == 4 && sizeof (handle_tid) == 8)
|
||
handle_tid = (thread_t) * (const uint32_t *) thread_handle;
|
||
else if (handle_len == sizeof (handle_tid))
|
||
handle_tid = * (const thread_t *) thread_handle;
|
||
else
|
||
error (_("Thread handle size mismatch: %d vs %zu (from libthread_db)"),
|
||
handle_len, sizeof (handle_tid));
|
||
|
||
for (thread_info *tp : inf->non_exited_threads ())
|
||
{
|
||
thread_db_thread_info *priv = get_thread_db_thread_info (tp);
|
||
|
||
if (priv != NULL && handle_tid == priv->tid)
|
||
return tp;
|
||
}
|
||
|
||
return NULL;
|
||
}
|
||
|
||
/* Return the thread handle associated the thread_info pointer TP. */
|
||
|
||
gdb::byte_vector
|
||
thread_db_target::thread_info_to_thread_handle (struct thread_info *tp)
|
||
{
|
||
thread_db_thread_info *priv = get_thread_db_thread_info (tp);
|
||
|
||
if (priv == NULL)
|
||
return gdb::byte_vector ();
|
||
|
||
int handle_size = sizeof (priv->tid);
|
||
gdb::byte_vector rv (handle_size);
|
||
|
||
memcpy (rv.data (), &priv->tid, handle_size);
|
||
|
||
return rv;
|
||
}
|
||
|
||
/* Get the address of the thread local variable in load module LM which
|
||
is stored at OFFSET within the thread local storage for thread PTID. */
|
||
|
||
CORE_ADDR
|
||
thread_db_target::get_thread_local_address (ptid_t ptid,
|
||
CORE_ADDR lm,
|
||
CORE_ADDR offset)
|
||
{
|
||
struct thread_info *thread_info;
|
||
process_stratum_target *beneath
|
||
= as_process_stratum_target (this->beneath ());
|
||
/* Find the matching thread. */
|
||
thread_info = find_thread_ptid (beneath, ptid);
|
||
|
||
/* We may not have discovered the thread yet. */
|
||
if (thread_info != NULL && thread_info->priv == NULL)
|
||
thread_info = thread_from_lwp (thread_info, ptid);
|
||
|
||
if (thread_info != NULL && thread_info->priv != NULL)
|
||
{
|
||
td_err_e err;
|
||
psaddr_t address;
|
||
thread_db_info *info = get_thread_db_info (beneath, ptid.pid ());
|
||
thread_db_thread_info *priv = get_thread_db_thread_info (thread_info);
|
||
|
||
/* Finally, get the address of the variable. */
|
||
if (lm != 0)
|
||
{
|
||
/* glibc doesn't provide the needed interface. */
|
||
if (!info->td_thr_tls_get_addr_p)
|
||
throw_error (TLS_NO_LIBRARY_SUPPORT_ERROR,
|
||
_("No TLS library support"));
|
||
|
||
/* Note the cast through uintptr_t: this interface only works if
|
||
a target address fits in a psaddr_t, which is a host pointer.
|
||
So a 32-bit debugger can not access 64-bit TLS through this. */
|
||
err = info->td_thr_tls_get_addr_p (&priv->th,
|
||
(psaddr_t)(uintptr_t) lm,
|
||
offset, &address);
|
||
}
|
||
else
|
||
{
|
||
/* If glibc doesn't provide the needed interface throw an error
|
||
that LM is zero - normally cases it should not be. */
|
||
if (!info->td_thr_tlsbase_p)
|
||
throw_error (TLS_LOAD_MODULE_NOT_FOUND_ERROR,
|
||
_("TLS load module not found"));
|
||
|
||
/* This code path handles the case of -static -pthread executables:
|
||
https://sourceware.org/ml/libc-help/2014-03/msg00024.html
|
||
For older GNU libc r_debug.r_map is NULL. For GNU libc after
|
||
PR libc/16831 due to GDB PR threads/16954 LOAD_MODULE is also NULL.
|
||
The constant number 1 depends on GNU __libc_setup_tls
|
||
initialization of l_tls_modid to 1. */
|
||
err = info->td_thr_tlsbase_p (&priv->th, 1, &address);
|
||
address = (char *) address + offset;
|
||
}
|
||
|
||
#ifdef THREAD_DB_HAS_TD_NOTALLOC
|
||
/* The memory hasn't been allocated, yet. */
|
||
if (err == TD_NOTALLOC)
|
||
/* Now, if libthread_db provided the initialization image's
|
||
address, we *could* try to build a non-lvalue value from
|
||
the initialization image. */
|
||
throw_error (TLS_NOT_ALLOCATED_YET_ERROR,
|
||
_("TLS not allocated yet"));
|
||
#endif
|
||
|
||
/* Something else went wrong. */
|
||
if (err != TD_OK)
|
||
throw_error (TLS_GENERIC_ERROR,
|
||
(("%s")), thread_db_err_str (err));
|
||
|
||
/* Cast assuming host == target. Joy. */
|
||
/* Do proper sign extension for the target. */
|
||
gdb_assert (exec_bfd);
|
||
return (bfd_get_sign_extend_vma (exec_bfd) > 0
|
||
? (CORE_ADDR) (intptr_t) address
|
||
: (CORE_ADDR) (uintptr_t) address);
|
||
}
|
||
|
||
return beneath->get_thread_local_address (ptid, lm, offset);
|
||
}
|
||
|
||
/* Implement the to_get_ada_task_ptid target method for this target. */
|
||
|
||
ptid_t
|
||
thread_db_target::get_ada_task_ptid (long lwp, long thread)
|
||
{
|
||
/* NPTL uses a 1:1 model, so the LWP id suffices. */
|
||
return ptid_t (inferior_ptid.pid (), lwp, 0);
|
||
}
|
||
|
||
void
|
||
thread_db_target::resume (ptid_t ptid, int step, enum gdb_signal signo)
|
||
{
|
||
process_stratum_target *beneath
|
||
= as_process_stratum_target (this->beneath ());
|
||
|
||
thread_db_info *info
|
||
= get_thread_db_info (beneath, (ptid == minus_one_ptid
|
||
? inferior_ptid.pid ()
|
||
: ptid.pid ()));
|
||
|
||
/* This workaround is only needed for child fork lwps stopped in a
|
||
PTRACE_O_TRACEFORK event. When the inferior is resumed, the
|
||
workaround can be disabled. */
|
||
if (info)
|
||
info->need_stale_parent_threads_check = 0;
|
||
|
||
beneath->resume (ptid, step, signo);
|
||
}
|
||
|
||
/* std::sort helper function for info_auto_load_libthread_db, sort the
|
||
thread_db_info pointers primarily by their FILENAME and secondarily by their
|
||
PID, both in ascending order. */
|
||
|
||
static bool
|
||
info_auto_load_libthread_db_compare (const struct thread_db_info *a,
|
||
const struct thread_db_info *b)
|
||
{
|
||
int retval;
|
||
|
||
retval = strcmp (a->filename, b->filename);
|
||
if (retval)
|
||
return retval < 0;
|
||
|
||
return a->pid < b->pid;
|
||
}
|
||
|
||
/* Implement 'info auto-load libthread-db'. */
|
||
|
||
static void
|
||
info_auto_load_libthread_db (const char *args, int from_tty)
|
||
{
|
||
struct ui_out *uiout = current_uiout;
|
||
const char *cs = args ? args : "";
|
||
struct thread_db_info *info;
|
||
unsigned unique_filenames;
|
||
size_t max_filename_len, pids_len;
|
||
int i;
|
||
|
||
cs = skip_spaces (cs);
|
||
if (*cs)
|
||
error (_("'info auto-load libthread-db' does not accept any parameters"));
|
||
|
||
std::vector<struct thread_db_info *> array;
|
||
for (info = thread_db_list; info; info = info->next)
|
||
if (info->filename != NULL)
|
||
array.push_back (info);
|
||
|
||
/* Sort ARRAY by filenames and PIDs. */
|
||
std::sort (array.begin (), array.end (),
|
||
info_auto_load_libthread_db_compare);
|
||
|
||
/* Calculate the number of unique filenames (rows) and the maximum string
|
||
length of PIDs list for the unique filenames (columns). */
|
||
|
||
unique_filenames = 0;
|
||
max_filename_len = 0;
|
||
pids_len = 0;
|
||
for (i = 0; i < array.size (); i++)
|
||
{
|
||
int pid = array[i]->pid;
|
||
size_t this_pid_len;
|
||
|
||
for (this_pid_len = 0; pid != 0; pid /= 10)
|
||
this_pid_len++;
|
||
|
||
if (i == 0 || strcmp (array[i - 1]->filename, array[i]->filename) != 0)
|
||
{
|
||
unique_filenames++;
|
||
max_filename_len = std::max (max_filename_len,
|
||
strlen (array[i]->filename));
|
||
|
||
if (i > 0)
|
||
pids_len -= strlen (", ");
|
||
pids_len = 0;
|
||
}
|
||
pids_len += this_pid_len + strlen (", ");
|
||
}
|
||
if (i)
|
||
pids_len -= strlen (", ");
|
||
|
||
/* Table header shifted right by preceding "libthread-db: " would not match
|
||
its columns. */
|
||
if (array.size () > 0 && args == auto_load_info_scripts_pattern_nl)
|
||
uiout->text ("\n");
|
||
|
||
{
|
||
ui_out_emit_table table_emitter (uiout, 2, unique_filenames,
|
||
"LinuxThreadDbTable");
|
||
|
||
uiout->table_header (max_filename_len, ui_left, "filename", "Filename");
|
||
uiout->table_header (pids_len, ui_left, "PIDs", "Pids");
|
||
uiout->table_body ();
|
||
|
||
/* Note I is incremented inside the cycle, not at its end. */
|
||
for (i = 0; i < array.size ();)
|
||
{
|
||
ui_out_emit_tuple tuple_emitter (uiout, NULL);
|
||
|
||
info = array[i];
|
||
uiout->field_string ("filename", info->filename);
|
||
|
||
std::string pids;
|
||
while (i < array.size () && strcmp (info->filename,
|
||
array[i]->filename) == 0)
|
||
{
|
||
if (!pids.empty ())
|
||
pids += ", ";
|
||
string_appendf (pids, "%u", array[i]->pid);
|
||
i++;
|
||
}
|
||
|
||
uiout->field_string ("pids", pids.c_str ());
|
||
|
||
uiout->text ("\n");
|
||
}
|
||
}
|
||
|
||
if (array.empty ())
|
||
uiout->message (_("No auto-loaded libthread-db.\n"));
|
||
}
|
||
|
||
/* Implement 'maintenance check libthread-db'. */
|
||
|
||
static void
|
||
maintenance_check_libthread_db (const char *args, int from_tty)
|
||
{
|
||
int inferior_pid = inferior_ptid.pid ();
|
||
struct thread_db_info *info;
|
||
|
||
if (inferior_pid == 0)
|
||
error (_("No inferior running"));
|
||
|
||
info = get_thread_db_info (current_inferior ()->process_target (),
|
||
inferior_pid);
|
||
if (info == NULL)
|
||
error (_("No libthread_db loaded"));
|
||
|
||
check_thread_db (info, true);
|
||
}
|
||
|
||
void
|
||
_initialize_thread_db (void)
|
||
{
|
||
/* Defer loading of libthread_db.so until inferior is running.
|
||
This allows gdb to load correct libthread_db for a given
|
||
executable -- there could be multiple versions of glibc,
|
||
and until there is a running inferior, we can't tell which
|
||
libthread_db is the correct one to load. */
|
||
|
||
libthread_db_search_path = xstrdup (LIBTHREAD_DB_SEARCH_PATH);
|
||
|
||
add_setshow_optional_filename_cmd ("libthread-db-search-path",
|
||
class_support,
|
||
&libthread_db_search_path, _("\
|
||
Set search path for libthread_db."), _("\
|
||
Show the current search path or libthread_db."), _("\
|
||
This path is used to search for libthread_db to be loaded into \
|
||
gdb itself.\n\
|
||
Its value is a colon (':') separate list of directories to search.\n\
|
||
Setting the search path to an empty list resets it to its default value."),
|
||
set_libthread_db_search_path,
|
||
NULL,
|
||
&setlist, &showlist);
|
||
|
||
add_setshow_zuinteger_cmd ("libthread-db", class_maintenance,
|
||
&libthread_db_debug, _("\
|
||
Set libthread-db debugging."), _("\
|
||
Show libthread-db debugging."), _("\
|
||
When non-zero, libthread-db debugging is enabled."),
|
||
NULL,
|
||
show_libthread_db_debug,
|
||
&setdebuglist, &showdebuglist);
|
||
|
||
add_setshow_boolean_cmd ("libthread-db", class_support,
|
||
&auto_load_thread_db, _("\
|
||
Enable or disable auto-loading of inferior specific libthread_db."), _("\
|
||
Show whether auto-loading inferior specific libthread_db is enabled."), _("\
|
||
If enabled, libthread_db will be searched in 'set libthread-db-search-path'\n\
|
||
locations to load libthread_db compatible with the inferior.\n\
|
||
Standard system libthread_db still gets loaded even with this option off.\n\
|
||
This option has security implications for untrusted inferiors."),
|
||
NULL, show_auto_load_thread_db,
|
||
auto_load_set_cmdlist_get (),
|
||
auto_load_show_cmdlist_get ());
|
||
|
||
add_cmd ("libthread-db", class_info, info_auto_load_libthread_db,
|
||
_("Print the list of loaded inferior specific libthread_db.\n\
|
||
Usage: info auto-load libthread-db"),
|
||
auto_load_info_cmdlist_get ());
|
||
|
||
add_cmd ("libthread-db", class_maintenance,
|
||
maintenance_check_libthread_db, _("\
|
||
Run integrity checks on the current inferior's libthread_db."),
|
||
&maintenancechecklist);
|
||
|
||
add_setshow_boolean_cmd ("check-libthread-db",
|
||
class_maintenance,
|
||
&check_thread_db_on_load, _("\
|
||
Set whether to check libthread_db at load time."), _("\
|
||
Show whether to check libthread_db at load time."), _("\
|
||
If enabled GDB will run integrity checks on inferior specific libthread_db\n\
|
||
as they are loaded."),
|
||
NULL,
|
||
NULL,
|
||
&maintenance_set_cmdlist,
|
||
&maintenance_show_cmdlist);
|
||
|
||
/* Add ourselves to objfile event chain. */
|
||
gdb::observers::new_objfile.attach (thread_db_new_objfile);
|
||
|
||
/* Add ourselves to inferior_created event chain.
|
||
This is needed to handle debugging statically linked programs where
|
||
the new_objfile observer won't get called for libpthread. */
|
||
gdb::observers::inferior_created.attach (thread_db_inferior_created);
|
||
}
|