The recent BP/WP changes for AArch64 swapping the order in add_lwp()
so that the process was added before the lwp. This was due to the lwp
creation requiring the process data.
This also needs changing in linux_attach().
Also add additional checks to make sure cannot attach to the same
process twice. Add test case for this - do this by splitting
attach.exp into distinct pass and error case sections.
Fixes gdb.server/ext-attach.exp on Aarch64.
gdb/gdbserver/ChangeLog:
* linux-low.c (linux_attach): Add process before lwp.
* server.c (attach_inferior): Check if already attached.
gdb/testsuite/ChangeLog:
* gdb.base/attach.exp: Add double attach test.
The recent BP/WP changes for AArch64 swapping the order in add_lwp()
so that the process was added before the lwp. This was due to the lwp
creation requiring the process data.
This also needs changing in linux_attach().
Fixes gdb.server/ext-attach.exp on Aarch64.
(This regression was hidden due to the racy nature of the gdb.server
tests - now they are no longer racy it'll be easier to spot. Also
checked X86).
gdb/gdbserver/ChangeLog:
2019-01-25 Alan Hayward <alan.hayward@arm.com>
* linux-low.c (linux_attach): Add process before lwp.
This commit applies all changes made after running the gdb/copyright.py
script.
Note that one file was flagged by the script, due to an invalid
copyright header
(gdb/unittests/basic_string_view/element_access/char/empty.cc).
As the file was copied from GCC's libstdc++-v3 testsuite, this commit
leaves this file untouched for the time being; a patch to fix the header
was sent to gcc-patches first.
gdb/ChangeLog:
Update copyright year range in all GDB files.
On some heavily loaded AArch64 boxes, GDB will sometimes hang forever when
the inferior creates a thread. This hang happens inside the kernel during
the ptrace call to set hardware watchpoints or hardware breakpoints.
Currently, GDB will always set hw wp/bp at the start of each thread even if
there are none set in the process.
This patch works around the issue by avoiding setting hw wp/bp if there
are none set for the process.
On an effected machine, this fix drastically reduces the racy nature of the
gdb.threads test set. I ran the entire gdb test suite across all processors
for 100 iterations, then ran the results through the racy tests script.
Without the patch, 58 .exp files in gdb.threads were marked as racy. After
the patch this reduced to the same ~14 tests as the non effected boxes.
Clearly GDB will still be subject to hangs on an effect box if hw wp/bp's are
used prior to creating inferior threads on a heavily loaded system.
To enable this in gdbserver, the sequence in gdbserver add_lwp() is switched
to the same as gdb order as gdb, to ensure the thread is registered before
calling new_thread(). This allows aarch64_linux_new_thread() to read the
ptid.
gdb/ChangeLog:
* nat/aarch64-linux-hw-point.c
(aarch64_linux_any_set_debug_regs_state): New function.
* nat/aarch64-linux-hw-point.h
(aarch64_linux_any_set_debug_regs_state): New declaration.
* nat/aarch64-linux.c (aarch64_linux_new_thread): Check if any
BPs or WPs are set.
gdb/gdbserver/ChangeLog:
* linux-low.c (add_lwp): Switch ordering.
-fsanitize=address pointed out a use-after-free in gdbserver. In
particular, handle_detach could reference "process" after it was
deleted by detach_inferior. Avoiding this also necessitated changing
target_ops::join to take a pid rather than a process_info*.
Tested by the buildbot using a few of the gdbserver builders.
gdb/gdbserver/ChangeLog
2018-11-29 Tom Tromey <tom@tromey.com>
* win32-low.c (win32_join): Take pid, not process.
* target.h (struct target_ops) <join>: Change argument type.
(join_inferior): Change argument name.
* spu-low.c (spu_join): Take pid, not process.
* server.c (handle_detach): Preserve pid before destroying
process.
* lynx-low.c (lynx_join): Take pid, not process.
* linux-low.c (linux_join): Take pid, not process.
This fixes a few instances of shadowing in gdbserver. These are all
simple fixes.
gdb/gdbserver/ChangeLog
2018-10-04 Tom Tromey <tom@tromey.com>
* server.c (handle_status): Rename inner "thread".
(process_serial_event): Declare "res" in 'm' case.
* linux-low.c (last_thread_of_process_p, find_lwp_pid)
(iterate_over_lwps): Rename inner "thread".
(linux_qxfer_libraries_svr4): Rename inner "len".
* gdbthread.h (find_thread_in_random): Rename inner "thread".
We start from a process_info pointer, pass down process->pid, and
then the target_kill implementations need to find the process from the
pid again. Pass the process_info pointer down directly instead.
gdb/gdbserver/ChangeLog:
2018-07-13 Pedro Alves <palves@redhat.com>
* linux-low.c (linux_kill): Change parameter to process_info
pointer instead of pid. Adjust.
* lynx-low.c (lynx_kill): Likewise.
* nto-low.c (nto_kill): Likewise.
* spu-low.c (spu_kill): Likewise.
* win32-low.c (win32_kill): Likewise.
* server.c (handle_v_kill, kill_inferior_callback)
(detach_or_kill_for_exit): Adjust.
* target.c (kill_inferior): Change parameter to process_info
pointer instead of pid. Adjust.
* target.h (struct target_ops) <kill>: Change parameter to
process_info pointer instead of pid. Adjust all implementations
and callers.
(kill_inferior): Likewise.
We start from a process_info pointer, pass down process->pid, and then
the target_detach and target_join implementations need to find the
process from the pid again. Pass the process_info pointer down
directly instead.
gdb/gdbserver/ChangeLog:
2018-07-13 Pedro Alves <palves@redhat.com>
* linux-low.c (linux_detach, linux_join): Change parameter to
process_info pointer instead of pid. Adjust.
* lynx-low.c (lynx_detach, lynx_join): Likewise.
* nto-low.c (nto_detach): Likewise.
* spu-low.c (spu_detach, spu_join): Likewise.
* win32-low.c (win32_detach, win32_join): Likewise.
* server.c (handle_detach, detach_or_kill_for_exit): Adjust.
* target.h (struct target_ops) <detach, join>: Change parameter to
process_info pointer instead of pid. Adjust all implementations
and callers.
(detach_inferior, join_inferior): Rename 'pid' parameter to
'proc'.
There's a buildroot where I want to debug a binary, and I tried to
connect to it from outside, but got very weird errors like
architecture mismatch or protocol errors. At last, after switching on
'--debug' for gdbserver I found a message 'Can't open /proc/pid/'
message and suddenly found that I forgot to mount procfs in my
buildroot.
Make discovering the problem easier by making GDB / GDBserver warn
(even without --debug) if /proc can not be accessed.
Native debugging:
(gdb) start
Temporary breakpoint 1 at 0x400835: file test.c, line 10.
Starting program: /tmp/test
warning: /proc is not accessible.
GDBserver/remote debugging:
$ ./gdbserver :9999 ./gdbserver
gdbserver: /proc is not accessible.
gdb/ChangeLog:
2018-07-04 Vyacheslav Barinov <v.barinov@samsung.com>
Pedro Alves <palves@redhat.com>
* linux-nat.c (linux_init_ptrace): Rename to ...
(linux_init_ptrace_procfs): ... this. Call
linux_proc_init_warnings.
(linux_nat_target::post_attach)
(linux_nat_target::post_startup_inferior): Adjust.
* nat/linux-procfs.c (linux_proc_init_warnings): Define function.
* nat/linux-procfs.h (linux_proc_init_warnings): Declare function.
gdb/gdbserver/ChangeLog:
2018-07-04 Vyacheslav Barinov <v.barinov@samsung.com>
Pedro Alves <palves@redhat.com>
* linux-low.c (initialize_low): Call linux_proc_init_warnings.
Collect per client specific global data items into struct client_state,
which is similar in purpose to remote.c::remote_state.
gdbserver/ChangeLog
* server.h (struct client_state): New.
* server.c (cont_thread, general_thread, multi_process)
(report_fork_events, report_vfork_events, report_exec_events)
(report_thread_events, swbreak_feature, hwbreak_feature)
(vCont_supported, disable_randomization, pass_signals)
(program_signals, program_signals_p, last_status, last_ptid, own_buf):
Moved to client_state.
* remote-utils.c (remote_debug, noack_mode)
(transport_is_reliable): Moved to client_state.
* tracepoint.c (current_traceframe): Moved to client_state.
Update all callers.
* server.c, remote-utils.c, tracepoint.c, fork-child.c,
linux-low.c, remote-utils.h, target.c: Use client_state.
[This patch should go on top of "linux_qxfer_libraries_svr4: Use
std::string", I should have sent them together as a series.]
I noticed that linux_qxfer_libraries_svr4 used xml_escape_text, which
returns an std::string. That string is then copied into a larger
buffer. It would be more efficient if we had a version of
xml_escape_text which appended to an existing string instead of
returning a new one. This is what this patch does.
I manually verified that the output of linux_qxfer_libraries_svr4 didn't
change before/after the patch.
gdb/ChangeLog:
* common/xml-utils.c (xml_escape_text): Move code to...
(xml_escape_text_append): ... this new function.
* common/xml-utils.h (xml_escape_text_append): New declaration.
* unittests/xml-utils-selftests.c (test_xml_escape_text_append):
New function.
(_initialize_xml_utils): register test_xml_escape_text_append as
a selftest.
gdb/gdbserver/ChangeLog:
* linux-low.c (linux_qxfer_libraries_svr4): Use
xml_escape_text_append.
Remove the to_supports_btrace target method and instead rely on detecting errors
when trying to enable recording. This will also provide a suitable error
message explaining why recording is not possible.
For remote debugging, gdbserver will now always advertise branch tracing related
packets. When talking to an older GDB, this will cause GDB to try to enable
branch tracing and gdbserver to report a suitable error message every time.
An older gdbserver will not advertise branch tracing related packets if the
one-time check failed, so a newer GDB with this patch will fail to enable branch
tracing at remote_enable_btrace() rather than at btrace_enable(). The error
message is the same in both cases so there should be no user-visible change.
gdb/
* btrace.c (btrace_enable): Remove target_supports_btrace call.
* nat/linux-btrace.c (perf_event_pt_event_type): Move.
(kernel_supports_bts, kernel_supports_pt, linux_supports_bts)
(linux_supports_pt, linux_supports_btrace): Remove.
(linux_enable_bts): Call cpu_supports_bts.
* nat/linux-btrace.h (linux_supports_btrace): Remove.
* remote.c (remote_supports_btrace): Remove.
(init_remote_ops): Remove remote_supports_btrace.
* target-delegates.c: Regenerated.
* target.c (target_supports_btrace): Remove.
* target.h (target_ops) <to_supports_btrace>: Remove
(target_supports_btrace): Remove.
* x86-linux-nat.c (x86_linux_create_target): Remove
linux_supports_btrace.
gdbserver/
* linux-low.c (linux_target_ops): Remove linux_supports_btrace.
* nto-low.c (nto_target_ops): Remove NULL for supports_btrace.
* spu-low.c (spu_target_ops): Likewise.
* win32-low.c (win32_target_ops): Likewise.
* server.c (supported_btrace_packets): Report packets unconditionally.
* target.h (target_ops) <supports_btrace>: Remove.
(target_supports_btrace): Remove.
This removes make_cleanup_restore_current_thread from gdbserver,
replacing it with a use of scoped_restore.
2018-02-08 Tom Tromey <tom@tromey.com>
* linux-low.c (install_software_single_step_breakpoints): Use
make_scoped_restore.
* inferiors.c (make_cleanup_restore_current_thread): Remove.
(do_restore_current_thread_cleanup): Remove.
* gdbthread.h (make_cleanup_restore_current_thread): Don't
declare.
This patch makes linux_ptrace_attach_fail_reason and
linux_ptrace_attach_fail_reason_string return std::string. It also
replaces usages of struct buffer with std::string. This allows getting
rid of a cleanup in in linux_ptrace_attach_fail_reason_string and
simplifies the code in general.
Something that looks odd to me is that in
linux_ptrace_attach_fail_reason, if the two messages are appended, there
is no separating space or \n, so the result won't be very nice. I left
it as-is for now though.
gdb/ChangeLog:
* nat/linux-ptrace.h (linux_ptrace_attach_fail_reason): Return
std::string.
(linux_ptrace_attach_fail_reason_string): Likewise.
* nat/linux-ptrace.c (linux_ptrace_attach_fail_reason):
Likewise.
(linux_ptrace_attach_fail_reason_string): Likewise.
* linux-nat.c (attach_proc_task_lwp_callback): Adjust.
gdb/gdbserver/ChangeLog:
* linux-low.c (attach_proc_task_lwp_callback): Adjust to
linux_ptrace_attach_fail_reason_string now returning an
std::string.
(linux_attach): Likewise.
* thread-db.c (attach_thread): Likewise.
As described in PR 18749, GDB/GDBserver may get an error on accessing
memory or register because the thread may disappear. However, some
path doesn't expect the error. This patch fixes this problem by
marking the register unavailable when PTRACE_PEEKUSER fails instead
of throwing error.
gdb/gdbserver:
2018-01-16 Yao Qi <yao.qi@linaro.org>
PR gdb/18749
* linux-low.c (fetch_register): Call supply_register instead of
error.
These functions were modified in the previous patch series, but I forgot
to update some comments.
gdb/gdbserver/ChangeLog:
* linux-low.c (resume_status_pending_p): Update comment.
(need_step_over_p): Update comment.
Replace with for_each_thread.
gdb/gdbserver/ChangeLog:
* linux-low.c (linux_resume_one_thread): Return void, take
parameter directly.
(linux_resume): Use for_each_thread.
Replace with find_thread/for_each_thread. I inlined the callbacks,
because they are relatively simple.
gdb/gdbserver/ChangeLog:
* linux-low.c (select_singlestep_lwp_callback): Remove.
(count_events_callback): Remove.
(select_event_lwp_callback): Remove.
(select_event_lwp): Use find_thread/for_each_thread.
Replace with find_thread. Writing a lambda inline in directly in the if
conditions would be a bit messy, so I chose to assign them to variables
instead.
gdb/gdbserver/ChangeLog:
* linux-low.c (not_stopped_callback): Return bool, take filter
argument directly.
(linux_wait_for_event_filtered): Use find_thread.
(linux_wait_1): Likewise.
Replace with find_thread. We could almost use find_thread_ptid, except
that find_lwp_pid uses the pid of the input ptid of the lwp is 0, so the
behavior is not quite the same.
gdb/gdbserver/ChangeLog:
* linux-low.c (same_lwp): Remove.
(find_lwp_pid): Use find_thread.
Replace with for_each_thread with pid filtering. The callback becomes
trivial enough that it's better to inline it.
gdb/gdbserver/ChangeLog:
* linux-low.c (delete_lwp_callback): Remove.
(linux_mourn): Use for_each_thread.
Replace it with find_thread. I also modified the code a bit to use a
lambda and a boolean.
gdb/gdbserver/ChangeLog:
* linux-low.c (struct counter): Remove.
(second_thread_of_pid_p): Remove.
(last_thread_of_process_p): Use find_thread.
This changes maybe_disable_address_space_randomization to be an RAII
class, rather than having it return a cleanup.
Regression tested by the buildbot.
ChangeLog
2017-11-26 Tom Tromey <tom@tromey.com>
* nat/linux-personality.h (class
maybe_disable_address_space_randomization): New class.
(maybe_disable_address_space_randomization): Don't declare
function.
* nat/linux-personality.c (restore_personality)
(make_disable_asr_cleanup): Remove.
(maybe_disable_address_space_randomization): Now a constructor.
(~maybe_disable_address_space_randomization): New destructor.
* linux-nat.c (linux_nat_create_inferior): Update.
gdbserver/ChangeLog
2017-11-26 Tom Tromey <tom@tromey.com>
* linux-low.c (linux_create_inferior): Update.
Replace with for_each_thread.
gdb/gdbserver/ChangeLog:
* linux-low.c (kill_one_lwp_callback): Return void, take
argument directly, don't filter on pid.
(linux_kill): Use for_each_thread.
Replace with find_thread. Instead of setting the flag in the callback,
make the callback return true/false, and check the result against NULL
in the caller.
gdb/gdbserver/ChangeLog:
* linux-low.c (resume_status_pending_p): Return bool, remove
flag_p argument.
(linux_resume): Use find_thread.
Replace it with for_each_thread.
gdb/gdbserver/ChangeLog:
* linux-low.c (struct thread_resume_array): Remove.
(linux_set_resume_request): Return void, take arguments
directly.
(linux_resume): Use for_each_thread.
Replace with for_each_thread. I inlined unsuspend_one_lwp in
unsuspend_all_lwps, since it is very simple.
gdb/gdbserver/ChangeLog:
* linux-low.c (unsuspend_one_lwp): Remove.
(unsuspend_all_lwps): Use for_each_thread, inline code from
unsuspend_one_lwp.
Replace find_inferior with find_thread. Since it may be useful in the
future, I added another overload to find_thread which filters based on a
ptid (using ptid_t::matches), so now iterate_over_lwps doesn't have to
do the filtering itself. iterate_over_lwps_filter is removed and
inlined into iterate_over_lwps.
gdb/gdbserver/ChangeLog:
* gdbthread.h (find_thread): Add overload with ptid_t filter.
* linux-low.c (struct iterate_over_lwps_args): Remove.
(iterate_over_lwps_filter): Remove.
(iterate_over_lwps): Use find_thread.
Replace with for_each_thread, and inline code from
reset_lwp_ptrace_options_callback.
gdb/gdbserver/ChangeLog:
* linux-low.c (reset_lwp_ptrace_options_callback): Remove.
(linux_handle_new_gdb_connection): Use for_each_thread, inline
code from reset_lwp_ptrace_options_callback.
This patch makes the syscalls_to_catch field of process_info an
std::vector<int>. The process_info structure must now be
newed/deleted.
In handle_extended_wait, the code that handles exec events destroys the
existing process_info and creates a new one. It moves the content of
syscalls_to_catch from the old to the new vector. I used std::move for
that (through an intermediary variable), which should have the same
behavior as the old code.
gdb/gdbserver/ChangeLog:
* inferiors.h (struct process_info): Add constructor, initialize
fields..
<syscalls_to_catch>: Change type to std::vector<int>.
* inferiors.c (add_process): Allocate process_info with new.
(remove_process): Free process_info with delete.
* linux-low.c (handle_extended_wait): Adjust.
(gdb_catching_syscalls_p, gdb_catch_this_syscall_p): Adjust.
* server.c (handle_general_set): Adjust.
