As a preparation for the next patch, which will move fork_inferior
from GDB to common/ (and therefore share it with gdbserver), it is
interesting to convert a few functions to C++.
This patch touches functions related to parsing command-line arguments
to the inferior (see gdb/fork-child.c:breakup_args), the way the
arguments are stored on fork_inferior (using std::vector instead of
char **), and the code responsible for dealing with argv also on
gdbserver.
I've taken this opportunity and decided to constify a few arguments to
fork_inferior/create_inferior as well, in order to make the code
cleaner. And now, on gdbserver, we're using xstrdup everywhere and
aren't checking for memory allocation failures anymore, as requested
by Pedro:
<https://sourceware.org/ml/gdb-patches/2017-03/msg00191.html>
Message-Id: <025ebdb9-90d9-d54a-c055-57ed2406b812@redhat.com>
Pedro Alves wrote:
> On the "== NULL" check: IIUC, the old NULL check was there to
> handle strdup returning NULL due to out-of-memory.
> See NULL checks and comments further above in this function.
> Now that you're using a std::vector, that doesn't work or make
> sense any longer, since if push_back fails to allocate space for
> its internal buffer (with operator new), our operator new replacement
> (common/new-op.c) calls malloc_failure, which aborts gdbserver.
>
> Not sure it makes sense to handle out-of-memory specially in
> the gdb/rsp-facing functions nowadays (maybe git blame/log/patch
> submission for that code shows some guidelines). Maybe (or, probably)
> it's OK to stop caring about it, but then we should consistently remove
> left over code, by using xstrdup instead and remove the NULL checks.
IMO this refactoring was very good to increase the readability of the
code as well, because some parts of the argument handling were
unnecessarily confusing before.
gdb/ChangeLog:
2017-04-12 Sergio Durigan Junior <sergiodj@redhat.com>
* common/common-utils.c (free_vector_argv): New function.
* common/common-utils.h: Include <vector>.
(free_vector_argv): New prototype.
* darwin-nat.c (darwin_create_inferior): Rewrite function
prototype in order to constify "exec_file" and accept a
"std::string" for "allargs".
* fork-child.c: Include <vector>.
(breakup_args): Rewrite function, using C++.
(fork_inferior): Rewrite function header, constify "exec_file_arg"
and accept "std::string" for "allargs". Update the code to
calculate "argv" based on "allargs". Update calls to "exec_fun"
and "execvp".
* gnu-nat.c (gnu_create_inferior): Rewrite function prototype in
order to constify "exec_file" and accept a "std::string" for
"allargs".
* go32-nat.c (go32_create_inferior): Likewise.
* inf-ptrace.c (inf_ptrace_create_inferior): Likewise.
* infcmd.c (run_command_1): Constify "exec_file". Use
"std::string" for inferior arguments.
* inferior.h (fork_inferior): Update prototype.
* linux-nat.c (linux_nat_create_inferior): Rewrite function
prototype in order to constify "exec_file" and accept a
"std::string" for "allargs".
* nto-procfs.c (procfs_create_inferior): Likewise.
* procfs.c (procfs_create_inferior): Likewise.
* remote-sim.c (gdbsim_create_inferior): Likewise.
* remote.c (extended_remote_run): Update code to accept
"std::string" as argument.
(extended_remote_create_inferior): Rewrite function prototype in
order to constify "exec_file" and accept a "std::string" for
"allargs".
* rs6000-nat.c (super_create_inferior): Likewise.
(rs6000_create_inferior): Likewise.
* target.h (struct target_ops) <to_create_inferior>: Likewise.
* windows-nat.c (windows_create_inferior): Likewise.
gdb/gdbserver/ChangeLog:
2017-04-12 Sergio Durigan Junior <sergiodj@redhat.com>
* server.c: Include <vector>.
<program_argv, wrapper_argv>: Convert to std::vector.
(start_inferior): Rewrite function to use C++.
(handle_v_run): Likewise. Update code that calculates the argv
based on the vRun packet; use C++.
(captured_main): Likewise.
I grew a bit tired of using ptid_get_{lwp,pid,tid} and friends, so I decided to
make it a bit easier to use by making it a proper class. The fields are now
private, so it's not possible to change a ptid_t field by mistake.
The new methods of ptid_t map to existing functions/practice like this:
ptid_t (pid, lwp, tid) -> ptid_build (pid, lwp, tid)
ptid_t (pid) -> pid_to_ptid (pid)
ptid.is_pid () -> ptid_is_pid (ptid)
ptid == other -> ptid_equal (ptid, other)
ptid != other -> !ptid_equal (ptid, other)
ptid.pid () -> ptid_get_pid (ptid)
ptid.lwp_p () -> ptid_lwp_p (ptid)
ptid.lwp () -> ptid_get_lwp (ptid)
ptid.tid_p () -> ptid_tid_p (ptid)
ptid.tid () -> ptid_get_tid (ptid)
ptid.matches (filter) -> ptid_match (ptid, filter)
I've replaced the implementation of the existing functions with calls to
the new methods. People are encouraged to gradually switch to using the
ptid_t methods instead of the functions (or we can change them all in
one pass eventually).
Also, I'm not sure if it's worth it (because of ptid_t's relatively
small size), but I have made the functions and methods take ptid_t
arguments by const reference instead of by value.
gdb/ChangeLog:
* common/ptid.h (struct ptid): Change to...
(class ptid_t): ... this.
<ptid_t>: New constructors.
<pid, lwp_p, lwp, tid_p, tid, is_pid, operator==, operator!=,
matches>: New methods.
<make_null, make_minus_one>: New static methods.
<pid>: Rename to...
<m_pid>: ...this.
<lwp>: Rename to...
<m_lwp>: ...this.
<tid>: Rename to...
<m_tid>: ...this.
(ptid_build, ptid_get_pid, ptid_get_lwp, ptid_get_tid, ptid_equal,
ptid_is_pid, ptid_lwp_p, ptid_tid_p, ptid_match): Take ptid arguments
as references, move comment to class ptid_t.
* common/ptid.c (null_ptid, minus_one_ptid): Initialize with
ptid_t static methods.
(ptid_build, pid_to_ptid, ptid_get_pid, ptid_get_tid,
ptid_equal, ptid_is_pid, ptid_lwp_p, ptid_tid_p, ptid_match):
Take ptid arguments as references, implement using ptid_t methods.
* unittests/ptid-selftests.c: New file.
* Makefile.in (SUBDIR_UNITTESTS_SRCS): Add
unittests/ptid-selftests.c.
(SUBDIR_UNITTESTS_OBS): Add unittests/ptid-selftests.o.
gdb/gdbserver/ChangeLog:
* server.c (handle_v_cont): Initialize thread_resume::thread
with null_ptid.
-Wwrite-strings flags this assignment as requiring a cast:
port = STDIO_CONNECTION_NAME;
because 'port' is a "char *", and STDIO_CONNECTION_NAME is a string
literal.
gdb/gdbserver/ChangeLog:
2017-04-05 Pedro Alves <palves@redhat.com>
* remote-utils.c (remote_prepare, remote_open): Constify.
* remote-utils.h (remote_prepare, remote_open): Constify.
* server.c (captured_main): Constify 'port' handling.
This applies the second part of GDB's End of Year Procedure, which
updates the copyright year range in all of GDB's files.
gdb/ChangeLog:
Update copyright year range in all GDB files.
Currently GDB never sends more than one action per vCont packet, when
connected in non-stop mode. A follow up patch will change that, and
it exposed a gdbserver problem with the vCont handling.
For example, this in non-stop mode:
=> vCont;s:p1.1;c
<= OK
Should be equivalent to:
=> vCont;s:p1.1
<= OK
=> vCont;c
<= OK
But gdbserver currently doesn't handle this. In the latter case,
"vCont;c" makes gdbserver clobber the previous step request. This
patch fixes that.
Note the server side must ignore resume actions for the thread that
has a pending %Stopped notification (and any other threads with events
pending), until GDB acks the notification with vStopped. Otherwise,
e.g., the following case is mishandled:
#1 => g (or any other packet)
#2 <= [registers]
#3 <= %Stopped T05 thread:p1.2
#4 => vCont s:p1.1;c
#5 <= OK
Above, the server must not resume thread p1.2 when it processes the
vCont. GDB can't know that p1.2 stopped until it acks the %Stopped
notification. (Otherwise it wouldn't send a default "c" action.)
(The vCont documentation already specifies this.)
Finally, special care must also be given to handling fork/vfork
events. A (v)fork event actually tells us that two processes stopped
-- the parent and the child. Until we follow the fork, we must not
resume the child. Therefore, if we have a pending fork follow, we
must not send a global wildcard resume action (vCont;c). We can still
send process-wide wildcards though.
(The comments above will be added as code comments to gdb in a follow
up patch.)
gdb/gdbserver/ChangeLog:
2016-10-26 Pedro Alves <palves@redhat.com>
* linux-low.c (handle_extended_wait): Link parent/child fork
threads.
(linux_wait_1): Unlink them.
(linux_set_resume_request): Ignore resume requests for
already-resumed and unhandled fork child threads.
* linux-low.h (struct lwp_info) <fork_relative>: New field.
* server.c (in_queued_stop_replies_ptid, in_queued_stop_replies):
New functions.
(handle_v_requests) <vCont>: Don't call require_running.
* server.h (in_queued_stop_replies): New declaration.
This patch consolidates the API of target_mourn_inferior between GDB
and gdbserver, in my continuing efforts to make sharing the
fork_inferior function possible between both.
GDB's version of the function did not care about the inferior's ptid
being mourned, but gdbserver's needed to know this information. Since
it actually makes sense to pass the ptid as an argument, instead of
depending on a global value directly (which GDB's version did), I
decided to make the generic API to accept it. I then went on and
extended all calls being made on GDB to include a ptid argument (which
ended up being inferior_ptid most of the times, anyway), and now we
have a more sane interface.
On GDB's side, after talking to Pedro a bit about it, we decided that
just an assertion to make sure that the ptid being passed is equal to
inferior_ptid would be enough for now, on the GDB side. We can remove
the assertion and perform more operations later if we ever pass
anything different than inferior_ptid.
Regression tested on our BuildBot, everything OK.
I'd appreciate a special look at gdb/windows-nat.c's modification
because I wasn't really sure what to do there. It seemed to me that
maybe I should build a ptid out of the process information there, but
then I am almost sure the assertion on GDB's side would trigger.
gdb/ChangeLog:
2016-09-19 Sergio Durigan Junior <sergiodj@redhat.com>
* darwin-nat.c (darwin_kill_inferior): Adjusting call to
target_mourn_inferior to include ptid_t argument.
* fork-child.c (startup_inferior): Likewise.
* gnu-nat.c (gnu_kill_inferior): Likewise.
* inf-ptrace.c (inf_ptrace_kill): Likewise.
* infrun.c (handle_inferior_event_1): Likewise.
* linux-nat.c (linux_nat_attach): Likewise.
(linux_nat_kill): Likewise.
* nto-procfs.c (interrupt_query): Likewise.
(procfs_interrupt): Likewise.
(procfs_kill_inferior): Likewise.
* procfs.c (procfs_kill_inferior): Likewise.
* record.c (record_mourn_inferior): Likewise.
* remote-sim.c (gdbsim_kill): Likewise.
* remote.c (remote_detach_1): Likewise.
(remote_kill): Likewise.
* target.c (target_mourn_inferior): Change declaration to accept
new ptid_t argument; use gdb_assert on it.
* target.h (target_mourn_inferior): Move function prototype from
here...
* target/target.h (target_mourn_inferior): ... to here. Adjust it
to accept new ptid_t argument.
* windows-nat.c (get_windows_debug_event): Adjusting call to
target_mourn_inferior to include ptid_t argument.
gdb/gdbserver/ChangeLog:
2016-09-19 Sergio Durigan Junior <sergiodj@redhat.com>
* server.c (start_inferior): Call target_mourn_inferior instead of
mourn_inferior; pass ptid_t argument to it.
(resume): Likewise.
(handle_target_event): Likewise.
* target.c (target_mourn_inferior): New function.
* target.h (mourn_inferior): Delete macro.
The last commit was supposed to have the reference to ptrace () removed.
The patch didn't get updated correctly before the commit. This commit
fixes the comment as requested
gdbserver/ChangeLog
2016-09-06 Carl Love <cel@us.ibm.com>
* server.c (start_inferior): Fixed comment, requested comment change
didn't get updated correctly. Removed reference to ptrace () call as
it is only true on Linux systems.
The test checks to make sure GDB exits cleanly if there is
no valid target binary. Currently, ppc and S390 fail on this
test. The function target_post_create_inferior () calls
linux_post_create_inferior () which calls the architecture
specific functions s390_arch_setup () and ppc_arch_setup ()
which make ptrace calls to access the architecture specific
registers. These ptrace calls fail because the process does
not exist causing GDB to exit on error.
This patch checks to see if the initial ptrace (PTRACE_TRACEME, ...)
call returned a status of TARGET_WAITKIND_EXITED indicating the
target has already exited. If the target has exited, then the
target_post_create_inferior () is not called since there is no
inferior to be setup. The test to see if the initial ptrace
call succeeded is done after the ptrace (PTRACE_TRACEME, ...)
call and the wait for the inferior process to stop, assuming
it exists, has occurred.
The patch has been tested on X86 64-bit, ppc64 and s390. If
fixes the test failures on ppc64 and s390. The test does not
fail on X86 64-bit. The patch does not introduce any additional
regression failures on any of these three platforms.
gdbserver/ChangeLog
2016-09-06 Carl Love <cel@us.ibm.com>
* server.c (start_inferior): Do not call
function target_post_create_inferior () if the
inferior process has already exited.
This commit implements a new function, target_continue, on top of the
target_resume function. Then, it replaces all calls to target_resume
by calls to target_continue or to the already existing
target_continue_no_signal.
This is one of the (many) necessary steps needed to consolidate the
target interface between GDB and gdbserver. In particular, I am
interested in the impact this change will have on the unification of
the fork_inferior function (which I have been working on).
Tested on the BuildBot, no regressions introduced.
gdb/gdbserver/ChangeLog:
2016-09-31 Sergio Durigan Junior <sergiodj@redhat.com>
* server.c (start_inferior): New variable 'ptid'. Replace calls
to the_target->resume by target_continue{,_no_signal}, depending
on the case.
* target.c (target_stop_and_wait): Call target_continue_no_signal
instead of the_target->resume.
(target_continue): New function.
gdb/ChangeLog:
2016-09-31 Sergio Durigan Junior <sergiodj@redhat.com>
* fork-child.c (startup_inferior): Replace calls to target_resume
by target_continue{,_no_signal}, depending on the case.
* linux-nat.c (cleanup_target_stop): Call
target_continue_no_signal instead of target_resume.
* procfs.c (procfs_wait): Likewise.
* target.c (target_continue): New function.
* target/target.h (target_continue): New prototype.
gdb's (or gdbserver's) own signal handling should not interfere with
the signal dispositions their spawned children inherit. However, it
currently does. For example, some paths in gdb cause SIGPIPE to be
set to SIG_IGN, and as consequence, the child starts with SIGPIPE to
set to SIG_IGN too, even though gdb was started with SIGPIPE set to
SIG_DFL.
This is because the exec family of functions does not reset the signal
disposition of signals that are set to SIG_IGN:
http://pubs.opengroup.org/onlinepubs/7908799/xsh/execve.html
Signals set to the default action (SIG_DFL) in the calling process
image are set to the default action in the new process
image. Signals set to be ignored (SIG_IGN) by the calling process
image are set to be ignored by the new process image. Signals set to
be caught by the calling process image are set to the default action
in the new process image (see <signal.h>).
And neither does it reset signal masks or flags.
In order to be transparent, when spawning new child processes to debug
(with "run", etc.), reset signal actions and mask back to what was
originally inherited from gdb/gdbserver's parent, just before execing
the target program to debug.
gdb/ChangeLog:
2016-08-09 Pedro Alves <palves@redhat.com>
PR gdb/18653
* Makefile.in (SFILES): Add
common/signals-state-save-restore.c.
(HFILES_NO_SRCDIR): Add common/signals-state-save-restore.h.
(COMMON_OBS): Add signals-state-save-restore.o.
(signals-state-save-restore.o): New rule.
* configure: Regenerate.
* fork-child.c: Include "signals-state-save-restore.h".
(fork_inferior): Call restore_original_signals_state.
* main.c: Include "signals-state-save-restore.h".
(captured_main): Call save_original_signals_state.
* common/common.m4: Add sigaction to AC_CHECK_FUNCS checks.
* common/signals-state-save-restore.c: New file.
* common/signals-state-save-restore.h: New file.
gdb/gdbserver/ChangeLog:
2016-08-09 Pedro Alves <palves@redhat.com>
PR gdb/18653
* Makefile.in (OBS): Add signals-state-save-restore.o.
(signals-state-save-restore.o): New rule.
* config.in: Regenerate.
* configure: Regenerate.
* linux-low.c: Include "signals-state-save-restore.h".
(linux_create_inferior): Call
restore_original_signals_state.
* server.c: Include "dispositions-save-restore.h".
(captured_main): Call save_original_signals_state.
gdb/testsuite/ChangeLog:
2016-08-09 Pedro Alves <palves@redhat.com>
PR gdb/18653
* gdb.base/signals-state-child.c: New file.
* gdb.base/signals-state-child.exp: New file.
* gdb.gdb/selftest.exp (do_steps_and_nexts): Add new pattern.
GDBserver with software single step should be able to claim supporting
vCont s and S actions, so that GDB knows the remote target can do
single step. It doesn't matter to GDB that the single step in the
remote target is done via hardware or software.
gdb/gdbserver:
2016-07-21 Yao Qi <yao.qi@linaro.org>
* server.c (handle_v_requests): Support s and S actions
if target_supports_software_single_step return true.
Nowadays, there are three types of breakpoint in GDBserver,
- gdb breakpoints,
- reinsert breakpoints, used for software single step,
- other breakpoints, used for tracepoint,
but we only have one 'struct breakpoint' for all of them. Some fields
are only useful to one type of breakpoint. For example, cond_list
and command_list are only used by gdb breakpoints, while handler is
only used by other breakpoints.
This patch changes 'struct breakpoint' to a base class, which has fields
needed by all breakpoint types, also add three sub-classes to
'struct breakpoint' to these three types of breakpoints.
gdb/gdbserver:
2016-07-21 Yao Qi <yao.qi@linaro.org>
* mem-break.c (struct breakpoint) <cond_list>: Remove.
<command_list, handler>: Remove.
(struct gdb_breakpoint): New.
(struct other_breakpoint): New.
(struct reinsert_breakpoint): New.
(is_gdb_breakpoint): New function.
(any_persistent_commands): Update command_list if
is_gdb_breakpoint returns true.
(set_breakpoint): Create breakpoints according to their types.
(find_gdb_breakpoint): Return 'struct gdb_breakpoint *'.
(set_gdb_breakpoint_1): Likewise.
(set_gdb_breakpoint): Likewise.
(clear_breakpoint_conditions): Change parameter type to
'struct gdb_breakpoint *'.
(clear_breakpoint_commands): Likewise.
(clear_breakpoint_conditions_and_commands): Likewise.
(add_condition_to_breakpoint): Likewise.
(add_breakpoint_condition): Likewise.
(add_commands_to_breakpoint): Likewise.
(check_breakpoints): Check other_breakpoint.
(clone_one_breakpoint): Clone breakpopint according to its type.
* mem-break.h (struct gdb_breakpoint): Declare.
(set_gdb_breakpoint): Update declaration.
(clear_breakpoint_conditions_and_commands): Likewise.
(add_breakpoint_condition): Likewise.
(add_breakpoint_commands): Likewise.
* server.c (process_point_options): Change parameter type to
'struct gdb_breakpoint *'.
On powerpc64, qSymbol query may require gdb to read a function
descriptor, sending a vFile packet to gdbserver. Thus, we need
to handle 'v' packet in look_up_one_symbol.
vFile replies may be quite long, and require reallocating own_buf.
Since handle_v_requests assumes the buffer is the static global own_buf
from server.c and reallocates it, we need to make own_buf global and
use it from look_up_one_symbol instead of using our own auto variable.
I've also done the same change in relocate_instruction, just in case.
On gdb side, in remote_check_symbols, rs->buf may be clobbered by vFile
handling, yet we need its contents for the reply (the symbol name is
stored there). Allocate a new buffer instead.
This broke fast tracepoints on powerpc64, due to errors in reading IPA
symbols.
gdb/ChangeLog:
* remote.c (remote_check_symbols): Allocate own buffer for reply.
gdbserver/ChangeLog:
* remote-utils.c (look_up_one_symbol): Remove own_buf, handle 'v'
packets.
(relocate_instruction): Remove own_buf.
* server.c (own_buf): Make global.
(handle_v_requests): Make global.
* server.h (own_buf): New declaration.
(handle_v_requests): New prototype.
For a forthcoming patch, I need a "skip_to_colon" function. I noticed
there are two skip_to_semicolon (one in gdb and one in gdbserver). I
thought we could put it in common/, and generalize it for any character.
It turns out that the strchrnul function does exactly that. I imported
the corresponding module from gnulib, for those systems that do not have
it.
There are probably more places where this function can be used instead
of doing the work by hand (I am looking at
remote-utils.c::look_up_one_symbol).
gdb/ChangeLog:
* remote.c (skip_to_semicolon): Remove.
(remote_parse_stop_reply): Use strchrnul instead of
skip_to_semicolon.
* gnulib/update-gnulib.sh (IMPORTED_GNULIB_MODULES): Add
strchrnul.
* gnulib/aclocal.m4: Regenerate.
* gnulib/config.in: Regenerate.
* gnulib/configure: Regenerate.
* gnulib/import/Makefile.am: Regenerate.
* gnulib/import/Makefile.in: Regenerate.
* gnulib/import/m4/gnulib-cache.m4: Regenerate.
* gnulib/import/m4/gnulib-comp.m4: Regenerate.
* gnulib/import/m4/rawmemchr.m4: New file.
* gnulib/import/m4/strchrnul.m4: New file.
* gnulib/import/rawmemchr.c: New file.
* gnulib/import/rawmemchr.valgrind: New file.
* gnulib/import/strchrnul.c: New file.
* gnulib/import/strchrnul.valgrind: New file.
gdb/gdbserver/ChangeLog:
* server.c (skip_to_semicolon): Remove.
(process_point_options): Use strchrnul instead of
skip_to_semicolon.
This adds a new QCatchSyscalls packet to enable 'catch syscall', and new
stop reasons "syscall_entry" and "syscall_return" for those events. It
is currently only supported on Linux x86 and x86_64.
gdb/ChangeLog:
2016-01-12 Josh Stone <jistone@redhat.com>
Philippe Waroquiers <philippe.waroquiers@skynet.be>
* NEWS (Changes since GDB 7.10): Mention QCatchSyscalls and the
syscall_entry and syscall_return stop reasons. Mention GDB
support for remote catch syscall.
* remote.c (PACKET_QCatchSyscalls): New enum.
(remote_set_syscall_catchpoint): New function.
(remote_protocol_features): New element for QCatchSyscalls.
(remote_parse_stop_reply): Parse syscall_entry/return stops.
(init_remote_ops): Install remote_set_syscall_catchpoint.
(_initialize_remote): Config QCatchSyscalls.
* linux-nat.h (struct lwp_info) <syscall_state>: Comment typo.
gdb/doc/ChangeLog:
2016-01-12 Josh Stone <jistone@redhat.com>
Philippe Waroquiers <philippe.waroquiers@skynet.be>
* gdb.texinfo (Remote Configuration): List the QCatchSyscalls packet.
(Stop Reply Packets): List the syscall entry and return stop reasons.
(General Query Packets): Describe QCatchSyscalls, and add it to the
table and the detailed list of stub features.
gdb/gdbserver/ChangeLog:
2016-01-12 Josh Stone <jistone@redhat.com>
Philippe Waroquiers <philippe.waroquiers@skynet.be>
* inferiors.h: Include "gdb_vecs.h".
(struct process_info): Add syscalls_to_catch.
* inferiors.c (remove_process): Free syscalls_to_catch.
* remote-utils.c (prepare_resume_reply): Report syscall_entry and
syscall_return stops.
* server.h (UNKNOWN_SYSCALL, ANY_SYSCALL): Define.
* server.c (handle_general_set): Handle QCatchSyscalls.
(handle_query): Report support for QCatchSyscalls.
* target.h (struct target_ops): Add supports_catch_syscall.
(target_supports_catch_syscall): New macro.
* linux-low.h (struct linux_target_ops): Add get_syscall_trapinfo.
(struct lwp_info): Add syscall_state.
* linux-low.c (handle_extended_wait): Mark syscall_state as an entry.
Maintain syscall_state and syscalls_to_catch across exec.
(get_syscall_trapinfo): New function, proxy to the_low_target.
(linux_low_ptrace_options): Enable PTRACE_O_TRACESYSGOOD.
(linux_low_filter_event): Toggle syscall_state entry/return for
syscall traps, and set it ignored for all others.
(gdb_catching_syscalls_p): New function.
(gdb_catch_this_syscall_p): New function.
(linux_wait_1): Handle SYSCALL_SIGTRAP.
(linux_resume_one_lwp_throw): Add PTRACE_SYSCALL possibility.
(linux_supports_catch_syscall): New function.
(linux_target_ops): Install it.
* linux-x86-low.c (x86_get_syscall_trapinfo): New function.
(the_low_target): Install it.
gdb/testsuite/ChangeLog:
2016-01-12 Josh Stone <jistone@redhat.com>
Philippe Waroquiers <philippe.waroquiers@skynet.be>
* gdb.base/catch-syscall.c (do_execve): New variable.
(main): Conditionally trigger an execve.
* gdb.base/catch-syscall.exp: Enable testing for remote targets.
(test_catch_syscall_execve): New, check entry/return across execve.
(do_syscall_tests): Call test_catch_syscall_execve.
The GNU Coding Standards say:
"Please do not include any trademark acknowledgements in GNU
software packages or documentation."
gdb/ChangeLog:
2016-01-12 Pedro Alves <palves@redhat.com>
Remove use of the registered trademark symbol throughout.
gdb/gdbserver/ChangeLog:
2016-01-12 Pedro Alves <palves@redhat.com>
Remove use of the registered trademark symbol throughout.
gdb/doc/ChangeLog:
2016-01-12 Pedro Alves <palves@redhat.com>
Remove use of the registered trademark symbol throughout.
gdb/ChangeLog:
* top.c (print_gdb_version): Change copyright year in version
message.
gdb/gdbserver/ChangeLog:
* gdbreplay.c (gdbreplay_version): Change copyright year in
version message.
* server.c (gdbserver_version): Likewise.
Tested on x86_64-pc-linux-gnu native-gdbserver, no new regressions.
gdb/gdbserver/ChangeLog:
* server.c (crc32_table): Delete.
(crc32): Use libiberty's xcrc32 function.
This patch enables support for conditional breakpoints if the target supports
software single step.
This was disabled before as the implementations of software single step were too
simple as discussed in
https://sourceware.org/ml/gdb-patches/2015-04/msg01110.html.
Since these issues are now fixed support can be added back.
New tests passing :
PASS: gdb.base/cond-eval-mode.exp: set breakpoint condition-evaluation
target and related...
No regressions, tested on ubuntu 14.04 ARMv7 and x86.
With gdbserver-{native,extended} / { -marm -mthumb }
gdb/gdbserver/ChangeLog:
* server.c (handle_query): Call target_supports_software_single_step.
This patch implements support for fork and exec events with target remote
mode Linux targets. For such targets with Linux kernels 2.5.46 and later,
this enables follow-fork-mode, detach-on-fork and fork and exec
catchpoints.
The changes required to implement this included:
* Don't exit from gdbserver if there are still active inferiors.
* Allow changing the active process in remote mode.
* Enable fork and exec events in remote mode.
* Print "Ending remote debugging" only when disconnecting.
* Combine remote_kill and extended_remote_kill into a single function
that can handle the multiple inferior case for target remote. Also,
the same thing for remote_mourn and extended_remote_mourn.
* Enable process-style ptids in target remote.
* Remove restriction on multiprocess mode in target remote.
gdb/gdbserver/ChangeLog:
* server.c (process_serial_event): Don't exit from gdbserver
in remote mode if there are still active inferiors.
gdb/ChangeLog:
* inferior.c (number_of_live_inferiors): New function.
(have_live_inferiors): Use number_of_live_inferiors in place
of duplicate code.
* inferior.h (number_of_live_inferiors): Declare new function.
* remote.c (set_general_process): Remove restriction on target
remote mode.
(remote_query_supported): Likewise.
(remote_detach_1): Exit in target remote mode only when there
is just one live inferior left.
(remote_disconnect): Unpush the target directly instead of
calling remote_mourn.
(remote_kill): Rewrite function to handle both target remote
and extended-remote. Call remote_kill_k.
(remote_kill_k): New function.
(extended_remote_kill): Delete function.
(remote_mourn, extended_remote_mourn): Combine functions into
one, remote_mourn, and enable extended functionality for target
remote.
(remote_pid_to_str): Enable "process" style ptid string for
target remote.
(remote_supports_multi_process): Remove restriction on target
remote mode.
In commit 6085d6f6, Z0 packet is disabled in aarch64 GDBserver if
the inferior is 32-bit or there may be multiple inferiors, because
Z0 packet isn't supported for arm then. Recently, Z0 packet
is supported in arm target, so we don't have such limitation in
aarch64 GDBserver, that is to say, aarch64 GDBserver can use Z0
packet in multi-arch/multi-inferior debugging when the inferior's
arch is arm.
Part of this patch is to revert 6085d6f6, and the rest of the patch
is to move some breakpoint related arm_* functions into
linux-aarch32-low.c in order to share them between arm and aarch64.
This patch is regression tested on aarch64-linux for debugging both
aarch64 programs and arm programs respectively.
gdb/gdbserver:
2015-12-07 Yao Qi <yao.qi@linaro.org>
* configure.srv: Append arm.o to srv_tgtobj for
aarch64*-*-linux* target.
* linux-aarch32-low.c (arm_abi_breakpoint): New macro. Moved
from linux-arm-low.c.
(arm_eabi_breakpoint, arm_breakpoint): Likewise.
(arm_breakpoint_len, thumb_breakpoint): Likewise.
(thumb_breakpoint_len, thumb2_breakpoint): Likewise.
(thumb2_breakpoint_len): Likewise.
(arm_is_thumb_mode, arm_breakpoint_at): Likewise.
(arm_breakpoint_kinds): Likewise.
(arm_breakpoint_kind_from_pc): Likewise.
(arm_sw_breakpoint_from_kind): Likewise.
(arm_breakpoint_kind_from_current_state): Likewise.
* linux-aarch32-low.h (arm_breakpoint_kind_from_pc): Declare.
(arm_sw_breakpoint_from_kind): Declare.
(arm_breakpoint_kind_from_current_state): Declare.
(arm_breakpoint_at): Declare.
* linux-aarch64-low.c (aarch64_sw_breakpoint_from_kind): Call
arm_sw_breakpoint_from_kind if process is 32-bit.
(aarch64_breakpoint_kind_from_pc): New function.
(aarch64_breakpoint_kind_from_current_state): New function.
(the_low_target): Initialize fields breakpoint_kind_from_pc
and breakpoint_kind_from_current_state.
* linux-arm-low.c (arm_breakpoint_kinds): Move to
linux-aarch32-low.c.
(arm_abi_breakpoint, arm_eabi_breakpoint): Likewise.
(arm_breakpoint, arm_breakpoint_len): Likewise.
(thumb_breakpoint, thumb_breakpoint_len): Likewise.
(thumb2_breakpoint, thumb2_breakpoint_len): Likewise.
(arm_is_thumb_mode): Likewise.
(arm_breakpoint_at): Likewise.
(arm_breakpoint_kind_from_pc): Likewise.
(arm_sw_breakpoint_from_kind): Likewise.
(arm_breakpoint_kind_from_current_state): Likewise.
Revert:
2015-08-04 Yao Qi <yao.qi@linaro.org>
* linux-aarch64-low.c (aarch64_supports_z_point_type): Return
0 for Z_PACKET_SW_BP if it may be used in multi-arch debugging.
* server.c (extended_protocol): Remove "static".
* server.h (extended_protocol): Declare it.
Rename target_ops.arch_setup to .post_create_inferior. In the Linux
hook, continue calling the low arch setup, then also set ptrace flags.
This corrects the possibility of running without flags, demonstrated by
a new test that would fail to catch a fork before.
gdb/gdbserver/ChangeLog:
2015-12-04 Josh Stone <jistone@redhat.com>
* target.h (struct target_ops) <arch_setup>: Rename to ...
(struct target_ops) <post_create_inferior>: ... this.
(target_arch_setup): Rename to ...
(target_post_create_inferior): ... this, calling post_create_inferior.
* server.c (start_inferior): Update target_arch_setup calls to
target_post_create_inferior.
* linux-low.c (linux_low_ptrace_options): Forward declare.
(linux_arch_setup): Update its comment for general use.
(linux_post_create_inferior): New, run arch_setup and setup ptrace.
(struct linux_target_ops): Use linux_post_create_inferior.
* lynx-low.c (struct lynx_target_ops): Update arch_setup stub comment
to post_create_inferior.
* nto-low.c (struct nto_target_ops): Likewise.
* spu-low.c (struct spu_target_ops): Likewise.
* win32-low.c (struct win32_target_ops): Likewise.
gdb/testsuite/ChangeLog:
2015-12-04 Josh Stone <jistone@redhat.com>
* gdb.base/catch-fork-static.exp: New.
When testing with "target remote" with "maint set target-non-stop on",
we regressions like this:
Running /home/pedro/gdb/mygit/build/../src/gdb/testsuite/gdb.threads/continue-pending-after-query.exp ...
FAIL: gdb.threads/continue-pending-after-query.exp: iter 4: continue until exit
FAIL: gdb.threads/continue-pending-after-query.exp: iter 6: continue until exit
FAIL: gdb.threads/continue-pending-after-query.exp: iter 10: continue until exit
=== gdb Summary ===
# of expected passes 28
# of unexpected failures 3
where gdb.log shows:
continue
Continuing.
Remote communication error. Target disconnected.: Connection reset by peer.
(gdb) FAIL: gdb.threads/continue-pending-after-query.exp: iter 4: continue until exit
Enabling gdb + gdbserver debug logs we see:
gdbserver: <<<< exiting linux_wait_1
gdbserver: handling possible serial event
gdbserver: Writing resume reply for LWP 11089.11089:0
gdbserver: handling possible serial event
gdbserver: GDBserver exiting
GDB: Packet received: OK
GDB: infrun: prepare_to_wait
GDB: Sending packet: $vStopped#55...Packet received: W0;process:2b51
GDB: Sending packet: $vStopped#55...Packet received: OK
GDB: infrun: target_wait (-1.0.0, status) =
GDB: infrun: -1.0.0 [Thread 0],
GDB: infrun: status->kind = no-resumed
GDB: Sending packet: $Hgp2b51.2b51#41...Remote connection closed
(gdb) FAIL: gdb.threads/continue-pending-after-query.exp: iter 1: continue until exit
Notice the "Packet received: W0;process:2b51" followed by
vStopped->OK.
That means the process exit notification was successfully sent to GDB
and GDB fetched it. That makes gdbserver exit, in
server.c:process_serial_event:
if (!extended_protocol && have_ran && !target_running ())
{
/* In non-stop, defer exiting until GDB had a chance to query
the whole vStopped list (until it gets an OK). */
if (QUEUE_is_empty (notif_event_p, notif_stop.queue))
{
/* Be transparent when GDB is connected through stdio -- no
need to spam GDB's console. */
if (!remote_connection_is_stdio ())
fprintf (stderr, "GDBserver exiting\n");
remote_close ();
exit (0);
}
}
However, GDB is still busy processing an earlier "no-resumed" event,
and sends a "Hg" packet, which errors out with "Remote connection
closed". IOW, it's not enough to wait for GDB to query the whole
vStopped list, gdbserver needs to wait until the exit event is really
processed.
The fix is to make gdbserver not disconnect until gdb does.
Tested on x86_64 Fedora, native gdbserver, remote + extended-remote +
with and without "maint set target-non-stop on".
gdb/gdbserver/ChangeLog:
2015-10-14 Pedro Alves <palves@redhat.com>
* remote-utils.c (readchar): Don't print "Got EOF" unless
debugging gdbserver.
* server.c (captured_main): Exit gdbserver if gdb disconnects when
in "target remote" mode and there are no processes left to debug.
(process_serial_event): Remove 'have_ran' static local and remove
logic that exits gdbserver in "target remote" mode.
Testing with "maint set target-non-stop on" causes regressions in
tests that rely on TARGET_WAITKIND_NO_RESUMED, which isn't modelled on
the RSP. In real all-stop, gdbserver detects the situation and
reporst error to GDB, and so the tests (e.g.,
gdb.threads/no-unwaited-for-left.exp) at fail quickly. But with
"maint set target-non-stop on", GDB instead hangs forever waiting for
a stop reply that never comes, and so the tests take longer to time
out.
This adds a new "N" stop reply packet that maps 1-1 to
TARGET_WAITKIND_NO_RESUMED.
gdb/ChangeLog:
2015-11-30 Pedro Alves <palves@redhat.com>
PR 14618
* NEWS (New remote packets): Mention the N stop reply.
* remote.c (remote_protocol_features): Add "no-resumed" entry.
(remote_query_supported): Report no-resumed+ support.
(remote_parse_stop_reply): Handle 'N'.
(process_stop_reply): Handle TARGET_WAITKIND_NO_RESUMED.
(remote_wait_as): Handle 'N' / TARGET_WAITKIND_NO_RESUMED.
(_initialize_remote): Register "set/show remote
no-resumed-stop-reply" commands.
gdb/doc/ChangeLog:
2015-11-30 Pedro Alves <palves@redhat.com>
PR 14618
* gdb.texinfo (Stop Reply Packets): Document the N stop reply.
(Remote Configuration): Add the "set/show remote
no-resumed-stop-reply" to the available settings table.
(General Query Packets): Document the "no-resumed" qSupported
feature.
gdb/gdbserver/ChangeLog:
2015-11-30 Pedro Alves <palves@redhat.com>
PR 14618
* linux-low.c (linux_wait_1): If the last resumed thread is gone,
report TARGET_WAITKIND_NO_RESUMED.
* remote-utils.c (prepare_resume_reply): Handle
TARGET_WAITKIND_NO_RESUMED.
* server.c (report_no_resumed): New global.
(handle_query) <qSupported>: Handle "no-resumed+". Report
"no-resumed+" support.
(resume): When the target reports TARGET_WAITKIND_NO_RESUMED, only
return error if the client doesn't support no-resumed events.
(push_stop_notification): New function.
(handle_target_event): Use it. Report TARGET_WAITKIND_NO_RESUMED
events if the client supports them.
gdb/testsuite/ChangeLog:
2015-11-30 Pedro Alves <palves@redhat.com>
* gdb.threads/no-unwaited-for-left.exp: Remove setup_kfail calls.
When testing with "maint set target-non-stop on", a few
threading-related tests expose an issue that requires new RSP packets.
Say there are 3 threads running, 1-3. If GDB tries to stop thread 1,
2 and 3, and then waits for their stops, but meanwhile say, thread 2
exits, GDB hangs forever waiting for a stop for thread 2 that won't
ever happen.
This patch fixes the issue by adding support for thread exit events to
the protocol. However, we don't want these always enabled, as they're
useless most of the time, and would slow down remote debugging. So I
made it so that GDB can enable/disable them, and then made gdb do that
around the cases that need it, which currently is only
infrun.c:stop_all_threads.
In turn, if we have thread exit events, then the extra "thread x
exited" traffic slows down attach-many-short-lived-threads.exp enough
that gdb has trouble keeping up with new threads that are spawned
while gdb tries to stop existing ones. To fix that I added support
for the counterpart thread created events too. Enabling those when we
try to stop threads ensures that new threads never get a chance to
themselves start new threads, killing the race.
gdb/doc/ChangeLog:
2015-11-30 Pedro Alves <palves@redhat.com>
* gdb.texinfo (Remote Configuration): List "set/show remote
thread-events" command in configuration table.
(Stop Reply Packets): Document "T05 create" stop
reason and 'w' stop reply.
(General Query Packets): Document QThreadEvents packet. Document
QThreadEvents qSupported feature.
gdb/gdbserver/ChangeLog:
2015-11-30 Pedro Alves <palves@redhat.com>
* linux-low.c (handle_extended_wait): Assert that the LWP's
waitstatus is TARGET_WAITKIND_IGNORE. If GDB wants to hear about
thread create events, leave the new child's status pending.
(linux_low_filter_event): If GDB wants to hear about thread exit
events, leave the LWP marked dead and don't delete it.
(linux_wait_for_event_filtered): Don't check for thread exit.
(filter_exit_event): New function.
(linux_wait_1): Use it, when returning an exit event.
(linux_resume_one_lwp_throw): Assert that the LWP's
waitstatus is TARGET_WAITKIND_IGNORE.
* remote-utils.c (prepare_resume_reply): Handle
TARGET_WAITKIND_THREAD_CREATED and TARGET_WAITKIND_THREAD_EXITED.
* server.c (report_thread_events): New global.
(handle_general_set): Handle QThreadEvents.
(handle_query) <qSupported>: Handle and report QThreadEvents+;
(handle_target_event): Handle TARGET_WAITKIND_THREAD_CREATED and
TARGET_WAITKIND_THREAD_EXITED.
* server.h (report_thread_events): Declare.
gdb/ChangeLog:
2015-11-30 Pedro Alves <palves@redhat.com>
* NEWS (New commands): Mention "set/show remote thread-events"
commands.
(New remote packets): Mention thread created/exited stop reasons
and QThreadEvents packet.
* infrun.c (disable_thread_events): New function.
(stop_all_threads): Disable/enable thread create/exit events.
Handle TARGET_WAITKIND_THREAD_EXITED.
(handle_inferior_event_1): Handle TARGET_WAITKIND_THREAD_CREATED
and TARGET_WAITKIND_THREAD_EXITED.
* remote.c (remove_child_of_pending_fork): Also remove threads of
threads that have TARGET_WAITKIND_THREAD_EXITED events.
(remote_parse_stop_reply): Handle "create" magic register. Handle
'w' stop reply.
(initialize_remote): Install remote_thread_events as
to_thread_events target hook.
(remote_thread_events): New function.
* target-delegates.c: Regenerate.
* target.c (target_thread_events): New function.
* target.h (struct target_ops) <to_thread_events>: New field.
(target_thread_events): Declare.
* target/waitstatus.c (target_waitstatus_to_string): Handle
TARGET_WAITKIND_THREAD_CREATED and TARGET_WAITKIND_THREAD_EXITED.
* target/waitstatus.h (enum target_waitkind)
<TARGET_WAITKIND_THREAD_CREATED, TARGET_WAITKIND_THREAD_EXITED):
New values.
There's currently no non-stop equivalent of the all-stop ^C (\003)
"packet" that GDB sends when a ctrl-c is pressed while a foreground
command is active. There's vCont;t, but that's defined to cause a
"signal 0" stop.
This fixes many tests that type ^C, when testing with extended-remote
with "maint set target-non-stop on". E.g.:
Continuing.
talk to me baby
PASS: gdb.base/interrupt.exp: process is alive
a
a
PASS: gdb.base/interrupt.exp: child process ate our char
^C
[Thread 22730.22730] #1 stopped.
0x0000003615ee6650 in __read_nocancel () at ../sysdeps/unix/syscall-template.S:81
81 T_PSEUDO (SYSCALL_SYMBOL, SYSCALL_NAME, SYSCALL_NARGS)
(gdb) FAIL: gdb.base/interrupt.exp: send_gdb control C
p func1 ()
gdb/
2015-11-30 Pedro Alves <palves@redhat.com>
* NEWS (New remote packets): Mention vCtrlC.
* remote.c (PACKET_vCtrlC): New enum value.
(async_remote_interrupt): Call target_interrupt instead of
target_stop.
(remote_interrupt_as): Remove 'ptid' parameter.
(remote_interrupt_ns): New function.
(remote_stop): Adjust.
(remote_interrupt): If the target is in non-stop mode, try
interrupting with vCtrlC.
(initialize_remote): Install set remote ctrl-c packet.
gdb/doc/
2015-11-30 Pedro Alves <palves@redhat.com>
* gdb.texinfo (Bootstrapping): Add "interrupting remote targets"
anchor.
(Packets): Document vCtrlC.
gdb/gdbserver/
2015-11-30 Pedro Alves <palves@redhat.com>
* server.c (handle_v_requests): Handle vCtrlC.
This fixes a gdbserver crash when running
gdb.threads/non-ldr-exc-1.exp with "maint set target-non-stop on".
The problem is that qSymbol is called when gdbserver has
current_thread == NULL.
gdb/gdbserver/ChangeLog:
2015-11-30 Pedro Alves <palves@redhat.com>
* gdbthread.h (find_any_thread_of_pid): Declare.
* inferiors.c (thread_of_pid, find_any_thread_of_pid): New
functions.
* server.c (handle_query): If current_thread is NULL, look for
another thread of the selected process.
This patch adds support for thread names in the remote protocol, and
updates gdb/gdbserver to use it. The information is added to the XML
description sent in response to the qXfer:threads:read packet.
gdb/ChangeLog:
* linux-nat.c (linux_nat_thread_name): Replace implementation by call
to linux_proc_tid_get_name.
* nat/linux-procfs.c (linux_proc_tid_get_name): New function,
implementation inspired by linux_nat_thread_name.
* nat/linux-procfs.h (linux_proc_tid_get_name): New declaration.
* remote.c (struct private_thread_info) <name>: New field.
(free_private_thread_info): Free name field.
(remote_thread_name): New function.
(thread_item_t) <name>: New field.
(clear_threads_listing_context): Free name field.
(start_thread): Get name xml attribute.
(thread_attributes): Add "name" attribute.
(remote_update_thread_list): Copy name field.
(init_remote_ops): Assign remote_thread_name callback.
* target.h (target_thread_name): Update comment.
* NEWS: Mention remote thread name support.
gdb/gdbserver/ChangeLog:
* linux-low.c (linux_target_ops): Use linux_proc_tid_get_name.
* server.c (handle_qxfer_threads_worker): Refactor to include thread
name in reply.
* target.h (struct target_ops) <thread_name>: New field.
(target_thread_name): New macro.
gdb/doc/ChangeLog:
* gdb.texinfo (Thread List Format): Mention thread names.
The target_process_qsupported method is called for each qSupported
feature that the common code does not recognize. The only current
implementation, for x86 Linux (x86_linux_process_qsupported), assumes
that it either is called with the "xmlRegisters=i386" feature, or that
it is isn't called at all, indicating the connected GDB predates x86
XML descriptions.
That's a bad assumption however. If GDB sends in a new/unknown (to
core gdbserver) feature after "xmlRegisters=i386", say, something like
qSupported:xmlRegisters=i386;UnknownFeature+, then when
target_process_qsupported is called for "UnknownFeature+",
x86_linux_process_qsupported clears the 'use_xml' global and calls
x86_linux_update_xmltarget, and gdbserver ends up _not_ reporting a
XML description...
This commit changes the target_process_qsupported API to instead pass
down a vector of unprocessed qSupported features in one go.
(There's an early call to target_process_qsupported(NULL) that
indicates "starting qSupported processing". There's no matching call
to mark the end of processing, though. I first fixed this by passing
(char *)-1 to indicate that, and adjusted the x86 backend to only
clear 'use_xml' when qSupported processing starts, and then only call
x86_linux_update_xmltarget() when (char *)-1 was passed. However, I
wasn't that happy with the hack and came up this alternative version.)
gdb/gdbserver/ChangeLog:
2015-11-19 Pedro Alves <palves@redhat.com>
* linux-low.c (linux_process_qsupported): Change prototype.
Adjust.
* linux-low.h (struct linux_target_ops) <process_qsupported>:
Change prototype.
* linux-x86-low.c (x86_linux_process_qsupported): Change prototype
and adjust to loop over all features.
* server.c (handle_query) <qSupported>: Adjust to call
target_process_qsupported once, passing it a vector of unprocessed
features.
* target.h (struct target_ops) <process_qsupported>: Change
prototype.
(target_process_qsupported): Adjust.
This is code parsing RSP signal numbers, checking whether the numbers
are indeed valid/known GDB signals, and then converting to host signal
numbers. I considered adding temporary enum gdb_signal variables
instead, but didn't really like the result.
gdb/gdbserver/ChangeLog:
2015-10-29 Pedro Alves <palves@redhat.com>
* server.c (handle_v_cont, process_serial_event): Add enum
gdb_signal casts to signal parsing code.
Fixes:
../../../src/gdb/gdbserver/linux-low.c: In function ‘int linux_low_read_btrace(btrace_target_info*, buffer*, int)’:
../../../src/gdb/gdbserver/linux-low.c:6827:48: error: invalid conversion from ‘int’ to ‘btrace_read_type’ [-fpermissive]
err = linux_read_btrace (&btrace, tinfo, type);
^
In file included from ../../../src/gdb/gdbserver/linux-low.c:98:0:
../../../src/gdb/gdbserver/../nat/linux-btrace.h:116:26: error: initializing argument 3 of ‘btrace_error linux_read_btrace(btrace_data*, btrace_target_info*, btrace_read_type)’ [-fpermissive]
extern enum btrace_error linux_read_btrace (struct btrace_data *btrace,
^
The cyclic dependency the comment talks about is no longer relevant:
https://sourceware.org/ml/gdb-patches/2015-10/msg00643.html
gdb/gdbserver/ChangeLog:
2015-10-29 Pedro Alves <palves@redhat.com>
* linux-low.c (linux_low_read_btrace): Change type of 'type'
parameter.
* server.c (handle_qxfer_btrace): Change type of 'type'
local.
* target.h (struct target_ops) <read_btrace>: Change type of
'type' parameter. Update comment.
There's two ways to set breakpoints in GDBServer.
- GDBServer setting its own breakpoints, through API set_breakpoint_at.
- GDBServer setting breakpoints according to the information in Z
packets, through API set_gdb_breakpoint.
Before this patch the breakpoint kinds were a concept unique to GDB and Z
packets, as GDBServer never had to set different kinds of breakpoint on its
own.
This patch teaches GDBServer to handle breakpoint kinds for its own
breakpoints. It generalizes the breakpoint kind as per Z packets to
represent different kinds of breakpoints directly set by GDBServer also.
GDBServer now querys breakpoint_kind_from_pc to know what breakpoint kind to
set on its own.
As the kind is now a differentiating factor equivalent to size for the
breakpoint struct and that it's size can be queried using
sw_breakpoint_from_kind, the size field has been replaced with the kind field.
All references to size are now replaced by kind or a call to bp_size that wraps
sw_breakpoing_from_kind and returns the size of the breakpoint in memory.
To fetch the software breakpoint data bp_opcode is called and wraps the
sw_breakpoint_from_kind call.
No regressions on Ubuntu 14.04 on ARMv7 and x86.
With gdbserver-{native,extended} / { -marm -mthumb }
gdb/gdbserver/ChangeLog:
* linux-low.c (initialize_low): Ajdust for breakpoint global variables
removal.
* mem-break.c : Remove breakpoint_data/breakpoint_len global variables.
(struct raw_breakpoint) <size>: Remove.
(struct raw_breakpoint) <kind>: Add.
(bp_size): New function.
(bp_opcode): Likewise.
(find_raw_breakpoint_at): Adjust for kind.
(insert_memory_breakpoint): Adjust for kind call bp_size,bp_opcode.
(remove_memory_breakpoint): Adjust for kind call bp_size.
(set_raw_breakpoint_at): Adjust for kind.
(set_breakpoint): Likewise.
(set_breakpoint_at): Call breakpoint_kind_from_pc.
(delete_raw_breakpoint): Adjust for kind.
(delete_breakpoint): Likewise.
(find_gdb_breakpoint): Likewise.
(set_gdb_breakpoint_1): Likewise.
(set_gdb_breakpoint): Likewise.
(delete_gdb_breakpoint_1): Likewise.
(delete_gdb_breakpoint): Likewise.
(uninsert_raw_breakpoint): Likewise.
(reinsert_raw_breakpoint): Likewise.
(set_breakpoint_data): Remove.
(validate_inserted_breakpoint): Adjust for kind call bp_size,bp_opcode.
(check_mem_read): Adjust for kind call bp_size.
(check_mem_write): Adjust for kind call bp_size,bp_opcode.
(clone_one_breakpoint): Adjust for kind.
* mem-break.h (set_gdb_breakpoint): Likewise.
(delete_gdb_breakpoint): Likewise.
* server.c (process_serial_event): Likewise.
Nowadays, GDB only knows whether architecture supports hardware single
step or software single step (through gdbarch hook software_single_step),
and for a given instruction or instruction sequence, GDB knows how to
do single step (hardware or software). However, GDB doesn't know whether
the target supports hardware single step. It is possible that the
architecture doesn't support hardware single step, such as arm, but
the target supports, such as simulator. This was discussed in this
thread https://www.sourceware.org/ml/gdb/2009-12/msg00033.html before.
I encounter this problem for aarch64 multi-arch support. When aarch64
debugs arm program, gdbarch is arm, so software single step is still
used. However, the underneath linux kernel does support hardware
single step, so IWBN to use it.
This patch is to add a new target_ops hook to_can_do_single_step, and
only use it in arm_linux_software_single_step to decide whether or not
to use hardware single step. On the native aarch64 linux target, 1 is
returned. On other targets, -1 is returned. On the remote target, if
the target supports s and S actions in the vCont? reply, then target
can do single step. However, old GDBserver will send s and S in the
reply to vCont?, which will confuse new GDB. For example, old GDBserver
on arm-linux will send s and S in the reply to vCont?, but it doesn't
support hardware single step. On the other hand, new GDBserver, on
arm-linux for example, will not send s and S in the reply to vCont?,
but old GDB thinks it doesn't support vCont packet at all. In order
to address this problem, I add a new qSupported feature vContSupported,
which indicates GDB wants to know the supported actions in the reply
to vCont?, and qSupported response contains vContSupported if the
stub is able tell supported vCont actions in the reply of vCont?.
If the patched GDB talks with patched GDBserver on x86, the RSP traffic
is like this:
-> $qSupported:...+;vContSupported+
<- ...+;vContSupported+
...
-> $vCont?
<- vCont;c;C;t;s;S;r
then, GDB knows the stub can do single step, and may stop using software
single step even the architecture doesn't support hardware single step.
If the patched GDB talks with patched GDBserver on arm, the last vCont?
reply will become:
<- vCont;c;C;t
GDB thinks the target doesn't support single step, so it will use software
single step.
If the patched GDB talks with unpatched GDBserver, the RSP traffic is like
this:
-> $qSupported:...+;vContSupported+
<- ...+
...
-> $vCont?
<- vCont;c;C;t;s;S;r
although GDBserver returns s and S, GDB still thinks GDBserver may not
support single step because it doesn't support vContSupported.
If the unpatched GDB talks with patched GDBserver on x86, the RSP traffic
is like:
-> $qSupported:...+;
<- ...+;vContSupported+
...
-> $vCont?
<- vCont;c;C;t;s;S;r
Since GDB doesn't sent vContSupported in the qSupported feature, GDBserver
sends s and S regardless of the support of hardware single step.
gdb:
2015-09-15 Yao Qi <yao.qi@linaro.org>
* aarch64-linux-nat.c (aarch64_linux_can_do_single_step): New
function.
(_initialize_aarch64_linux_nat): Install it to to_can_do_single_step.
* arm-linux-tdep.c (arm_linux_software_single_step): Return 0
if target_can_do_single_step returns 1.
* remote.c (struct vCont_action_support) <s, S>: New fields.
(PACKET_vContSupported): New enum.
(remote_protocol_features): New element for vContSupported.
(remote_query_supported): Append "vContSupported+".
(remote_vcont_probe): Remove support_s and support_S, use
rs->supports_vCont.s and rs->supports_vCont.S instead. Disable
vCont packet if c and C actions are not supported.
(remote_can_do_single_step): New function.
(init_remote_ops): Install it to to_can_do_single_step.
(_initialize_remote): Call add_packet_config_cmd.
* target.h (struct target_ops) <to_can_do_single_step>: New field.
(target_can_do_single_step): New macro.
* target-delegates.c: Re-generated.
gdb/gdbserver:
2015-09-15 Yao Qi <yao.qi@linaro.org>
* server.c (vCont_supported): New global variable.
(handle_query): Set vCont_supported to 1 if "vContSupported+"
matches. Append ";vContSupported+" to own_buf.
(handle_v_requests): Append ";s;S" to own_buf if target supports
hardware single step or vCont_supported is false.
(capture_main): Set vCont_supported to zero.
gdb/doc:
2015-09-15 Yao Qi <yao.qi@linaro.org>
* gdb.texinfo (General Query Packets): Add vContSupported to
tables of 'gdbfeatures' and 'stub features' supported in the
qSupported packet, as well as to the list containing stub
feature details.
In my patch https://sourceware.org/ml/gdb-patches/2015-04/msg01110.html
a new target_ops hook supports_conditional_breakpoints was added to
disable conditional breakpoints if target doesn't have hardware single
step. This patch is to generalize this hook from
supports_conditional_breakpoints to supports_hardware_single_step,
so that the following patch can use it.
gdb/gdbserver:
2015-09-15 Yao Qi <yao.qi@linaro.org>
* linux-low.c (linux_supports_conditional_breakpoints): Rename
it to ...
(linux_supports_hardware_single_step): ... New function.
(linux_target_ops): Update.
* lynx-low.c (lynx_target_ops): Set field
supports_hardware_single_step to target_can_do_hardware_single_step.
* nto-low.c (nto_target_ops): Likewise.
* spu-low.c (spu_target_ops): Likewise.
* win32-low.c (win32_target_ops): Likewise.
* target.c (target_can_do_hardware_single_step): New function.
* target.h (struct target_ops) <supports_conditional_breakpoints>:
Remove. <supports_hardware_single_step>: New field.
(target_supports_conditional_breakpoints): Remove.
(target_supports_hardware_single_step): New macro.
(target_can_do_hardware_single_step): Declare.
* server.c (handle_query): Use target_supports_hardware_single_step
instead of target_supports_conditional_breakpoints.
This patch implements support for exec events on extended-remote Linux
targets. Follow-exec-mode and rerun behave as expected. Catchpoints and
test updates are implemented in subsequent patches.
This patch was derived from a patch posted last October:
https://sourceware.org/ml/gdb-patches/2014-10/msg00877.html.
It was originally based on some work done by Luis Machado in 2013.
IMPLEMENTATION
----------------
Exec events are enabled via ptrace options.
When an exec event is detected by gdbserver, the existing process
data, along with all its associated lwp and thread data, is deleted
and replaced by data for a new single-threaded process. The new
process data is initialized with the appropriate parts of the state
of the execing process. This approach takes care of several potential
pitfalls, including:
* deleting the data for an execing non-leader thread before any
wait/sigsuspend occurs
* correctly initializing the architecture of the execed process
We then report the exec event using a new RSP stop reason, "exec".
When GDB receives an "exec" event, it saves the status in the event
structure's target_waitstatus field, like what is done for remote fork
events. Because the original and execed programs may have different
architectures, we skip parsing the section of the stop reply packet
that contains register data. The register data will be retrieved
later after the inferior's architecture has been set up by
infrun.c:follow_exec.
At that point the exec event is handled by the existing event handling
in GDB. However, a few changes were necessary so that
infrun.c:follow_exec could accommodate the remote target.
* Where follow-exec-mode "new" is handled, we now call
add_inferior_with_spaces instead of add_inferior with separate calls
to set up the program and address spaces. The motivation for this
is that add_inferior_with_spaces also sets up the initial architecture
for the inferior, which is needed later by target_find_description
when it calls target_gdbarch.
* We call a new target function, target_follow_exec. This function
allows us to store the execd_pathname in the inferior, instead of
using the static string remote_exec_file from remote.c. The static
string didn't work for follow-exec-mode "new", since once you switched
to the execed program, the original remote exec-file was lost. The
execd_pathname is now stored in the inferior's program space as a
REGISTRY field. All of the requisite mechanisms for this are
defined in remote.c.
gdb/gdbserver/ChangeLog:
* linux-low.c (linux_mourn): Static declaration.
(linux_arch_setup): Move in front of
handle_extended_wait.
(linux_arch_setup_thread): New function.
(handle_extended_wait): Handle exec events. Call
linux_arch_setup_thread. Make event_lwp argument a
pointer-to-a-pointer.
(check_zombie_leaders): Do not check stopped threads.
(linux_low_ptrace_options): Add PTRACE_O_TRACEEXEC.
(linux_low_filter_event): Add lwp and thread for exec'ing
non-leader thread if leader thread has been deleted.
Refactor code into linux_arch_setup_thread and call it.
Pass child lwp pointer by reference to handle_extended_wait.
(linux_wait_for_event_filtered): Update comment.
(linux_wait_1): Prevent clobbering exec event status.
(linux_supports_exec_events): New function.
(linux_target_ops) <supports_exec_events>: Initialize new member.
* lynx-low.c (lynx_target_ops) <supports_exec_events>: Initialize
new member.
* remote-utils.c (prepare_resume_reply): New stop reason 'exec'.
* server.c (report_exec_events): New global variable.
(handle_query): Handle qSupported query for exec-events feature.
(captured_main): Initialize report_exec_events.
* server.h (report_exec_events): Declare new global variable.
* target.h (struct target_ops) <supports_exec_events>: New
member.
(target_supports_exec_events): New macro.
* win32-low.c (win32_target_ops) <supports_exec_events>:
Initialize new member.
gdb/ChangeLog:
* infrun.c (follow_exec): Use process-style ptid for
exec message. Call add_inferior_with_spaces and
target_follow_exec.
* nat/linux-ptrace.c (linux_supports_traceexec): New function.
* nat/linux-ptrace.h (linux_supports_traceexec): Declare.
* remote.c (remote_pspace_data): New static variable.
(remote_pspace_data_cleanup): New function.
(get_remote_exec_file): New function.
(set_remote_exec_file_1): New function.
(set_remote_exec_file): New function.
(show_remote_exec_file): New function.
(remote_exec_file): Delete static variable.
(anonymous enum) <PACKET_exec_event_feature> New
enumeration constant.
(remote_protocol_features): Add entry for exec-events feature.
(remote_query_supported): Add client side of qSupported query
for exec-events feature.
(remote_follow_exec): New function.
(remote_parse_stop_reply): Handle 'exec' stop reason.
(extended_remote_run, extended_remote_create_inferior): Call
get_remote_exec_file and set_remote_exec_file_1.
(init_extended_remote_ops) <to_follow_exec>: Initialize new
member.
(_initialize_remote): Call
register_program_space_data_with_cleanup. Call
add_packet_config_cmd for remote exec-events feature.
Modify call to add_setshow_string_noescape_cmd for exec-file
to use new functions set_remote_exec_file and
show_remote_exec_file.
* target-debug.h, target-delegates.c: Regenerated.
* target.c (target_follow_exec): New function.
* target.h (struct target_ops) <to_follow_exec>: New member.
(target_follow_exec): Declare new function.
Running that test in a loop, I found a gdbserver core dump with the
following back trace:
Core was generated by `../gdbserver/gdbserver --once --multi :2346'.
Program terminated with signal SIGSEGV, Segmentation fault.
#0 0x0000000000406ab6 in inferior_regcache_data (inferior=0x0) at src/gdb/gdbserver/inferiors.c:236
236 return inferior->regcache_data;
(gdb) up
#1 0x0000000000406d7f in get_thread_regcache (thread=0x0, fetch=1) at src/gdb/gdbserver/regcache.c:31
31 regcache = (struct regcache *) inferior_regcache_data (thread);
(gdb) bt
#0 0x0000000000406ab6 in inferior_regcache_data (inferior=0x0) at src/gdb/gdbserver/inferiors.c:236
#1 0x0000000000406d7f in get_thread_regcache (thread=0x0, fetch=1) at src/gdb/gdbserver/regcache.c:31
#2 0x0000000000409271 in prepare_resume_reply (buf=0x20dd593 "", ptid=..., status=0x20edce0) at src/gdb/gdbserver/remote-utils.c:1147
#3 0x000000000040ab0a in vstop_notif_reply (event=0x20edcc0, own_buf=0x20dd590 "T05") at src/gdb/gdbserver/server.c:183
#4 0x0000000000426b38 in notif_write_event (notif=0x66e6c0 <notif_stop>, own_buf=0x20dd590 "T05") at src/gdb/gdbserver/notif.c:69
#5 0x0000000000426c55 in handle_notif_ack (own_buf=0x20dd590 "T05", packet_len=8) at src/gdb/gdbserver/notif.c:113
#6 0x000000000041118f in handle_v_requests (own_buf=0x20dd590 "T05", packet_len=8, new_packet_len=0x7fff742c77b8)
at src/gdb/gdbserver/server.c:2862
#7 0x0000000000413850 in process_serial_event () at src/gdb/gdbserver/server.c:4148
#8 0x0000000000413945 in handle_serial_event (err=0, client_data=0x0) at src/gdb/gdbserver/server.c:4196
#9 0x000000000041a1ef in handle_file_event (event_file_desc=5) at src/gdb/gdbserver/event-loop.c:429
#10 0x00000000004199b6 in process_event () at src/gdb/gdbserver/event-loop.c:184
#11 0x000000000041a735 in start_event_loop () at src/gdb/gdbserver/event-loop.c:547
#12 0x00000000004123d2 in captured_main (argc=4, argv=0x7fff742c7ac8) at src/gdb/gdbserver/server.c:3562
#13 0x000000000041252e in main (argc=4, argv=0x7fff742c7ac8) at src/gdb/gdbserver/server.c:3631
Clearly this means that a thread pushed a stop reply in the event
queue, and then before GDB confused the event, the whole process died,
along with its thread. But the pending thread event was left
dangling. When GDB fetched that event, gdbserver looked up the
corresponding thread, but found NULL; not expecting this, gdbserver
crashes when it tries to read this thread's registers.
gdb/gdbserver/
2015-08-21 Pedro Alves <palves@redhat.com>
PR gdb/18749
* inferiors.c (remove_thread): Discard any pending stop reply for
this thread.
* server.c (remove_all_on_match_pid): Rename to ...
(remove_all_on_match_ptid): ... this. Work with a filter ptid
instead of a pid.
(discard_queued_stop_replies): Change parameter to a ptid. Now
extern.
(handle_v_kill, kill_inferior_callback)
(process_serial_event): Adjust.
(captured_main): Call initialize_notif before starting the
program, thus before threads are created.
* server.h (discard_queued_stop_replies): Declare.
In all-stop mode, if the current thread disappears while stopping all
threads, gdbserver calls set_desired_thread(0) ['0' means "I want the
continue thread"] which just picks the first thread in the list.
This looks like a dangerous thing to do. GDBserver continues
processing whatever it was doing, but to the wrong thread. If
debugging more than one process, we may even pick the wrong process.
Instead, GDBserver should detect the situation and bail out of
whatever is was doing.
The backends used to pay attention to the set 'cont_thread' (the Hc
thread, used in the old way to resume threads, before vCont), but all
such 'cont_thread' checks have been eliminated meanwhile. The
remaining implicit dependencies that I found on there being a selected
thread in the backends are in the Ctrl-C handling, which some backends
use as thread to send a signal to. Even that seems to me to be better
handled by always using the first thread in the list or by using the
signal_pid PID.
In order to make this a systematic approach, I'm making
set_desired_thread never fallback to a random thread, and instead end
up with current_thread == NULL, like already done in non-stop mode.
Then I updated all callers to handle the situation.
I stumbled on this while fixing other bugs exposed by
gdb.threads/fork-plus-threads.exp test. The problems I saw were fixed
in a different way, but in any case, I think the potential for
problems is more or less obvious, and the resulting code looks a bit
less magical to me.
Tested on x86-64 Fedora 20, w/ native-extended-gdbserver board.
gdb/gdbserver/ChangeLog:
2015-08-21 Pedro Alves <palves@redhat.com>
* linux-low.c (wait_for_sigstop): Always switch to no thread
selected if the previously current thread dies.
* lynx-low.c (lynx_request_interrupt): Use the first thread's
process instead of the current thread's.
* remote-utils.c (input_interrupt): Don't check if there's no
current thread.
* server.c (gdb_read_memory, gdb_write_memory): If setting the
current thread to the general thread fails, error out.
(handle_qxfer_auxv, handle_qxfer_libraries)
(handle_qxfer_libraries_svr4, handle_qxfer_siginfo)
(handle_qxfer_spu, handle_qxfer_statictrace, handle_qxfer_fdpic)
(handle_query): Check if there's a thread selected instead of
checking whether there's any thread in the thread list.
(handle_qxfer_threads, handle_qxfer_btrace)
(handle_qxfer_btrace_conf): Don't error out early if there's no
thread in the thread list.
(handle_v_cont, myresume): Don't set the current thread to the
continue thread.
(process_serial_event) <Hg handling>: Also set thread_id if the
previous general thread is still alive.
(process_serial_event) <g/G handling>: If setting the current
thread to the general thread fails, error out.
* spu-low.c (spu_resume, spu_request_interrupt): Use the first
thread's lwp instead of the current thread's.
* target.c (set_desired_thread): If the desired thread was not
found, leave the current thread pointing to NULL. Return an int
(boolean) indicating success.
* target.h (set_desired_thread): Change return type to int.
Running gdb.threads/process-dies-while-handling-bp.exp against
gdbserver sometimes FAILs because GDBserver drops the connection, but
the logs leave no clue on what the reason could be. Running manually
a few times, I saw the same:
$ ./gdbserver/gdbserver --multi :9999 testsuite/gdb.threads/process-dies-while-handling-bp
Process testsuite/gdb.threads/process-dies-while-handling-bp created; pid = 12766
Listening on port 9999
Remote debugging from host 127.0.0.1
Listening on port 9999
Child exited with status 0
Child exited with status 0
What happened is that an exception escaped and gdbserver reopened the
connection, which led to that second "Listening on port 9999" output.
The error was a failure to access registers from a now-dead thread.
The exception probably shouldn't have escaped here, but meanwhile,
this at least makes the issue less mysterious.
Tested on x86_64 Fedora 20.
gdb/gdbserver/ChangeLog:
2015-08-06 Pedro Alves <palves@redhat.com>
* server.c (captured_main): On error, print the exception message
to stderr, and if run_once is set, throw a quit.
In multi-arch debugging, if GDB sends Z0 packet, GDBserver should be
able to do several things below:
- choose the right breakpoint instruction to insert according to the
information available, such as 'kind' in Z0 packet and address,
- choose the right breakpoint instruction to check memory writes and
validate inserted memory breakpoint
- be aware of different breakpoint instructions in $ARCH_breakpoint_at.
unfortunately GDBserver can't do them now. Although x86 GDBserver
supports multi-arch, it doesn't need to support them above because
breakpoint instruction on i686 and x86_64 is the same. However,
breakpoint instructions on aarch64 and arm (arm mode, thumb1, and thumb2)
are different.
I tried to teach aarch64 GDBserver backend to be really
multi-arch-capable in the following ways,
- linux_low_target return the right breakpoint instruction according to
the 'kind' in Z0 packet, and insert_memory_breakpoint can do the right
thing.
- once breakpoint is inserted, the breakpoint data and length is recorded
in each breakpoint object, so that validate_breakpoint and
check_mem_write can get the right breakpoint instruction from each
breakpoint object, rather than from global variable breakpoint_data.
- linux_low_target needs another hook function for pc increment after
hitting a breakpoint.
- let set_breakpoint_at, which is widely used for tracepoint, use the
'default' breakpoint instruction. We can always use aarch64 breakpoint
instruction since arm doesn't support tracepoint yet.
looks it is not a small piece of work, so I decide to disable Z0 packet
on multi-arch, which means aarch64 GDBserver only supports Z0 packet
if it is started to debug only one process (extended protocol is not
used) and process target description is 64-bit.
gdb/gdbserver:
2015-08-04 Yao Qi <yao.qi@linaro.org>
* linux-aarch64-low.c (aarch64_supports_z_point_type): Return
0 for Z_PACKET_SW_BP if it may be used in multi-arch debugging.
* server.c (extended_protocol): Remove "static".
* server.h (extended_protocol): Declare it.
Nowadays, when --wrapper is used, GDBserver skips extra traps/stops
in the wrapper program, and stops at the first instruction of the
program to be debugged. However, GDBserver created target description
in the first stop of inferior, and the executable of the inferior
is the wrapper program rather than the program to be debugged. In
this way, the target description can be wrong if the architectures
of wrapper program and program to be debugged are different. This
is shown by some fails in gdb.server/wrapper.exp on buildbot.
We are testing i686-linux GDB (Fedora-i686) on an x86_64-linux box
(fedora-x86-64-4) in buildbot, such configuration causes fails in
gdb.server/wrapper.exp like this:
spawn /home/gdb-buildbot-2/fedora-x86-64-4/fedora-i686/build/gdb/testsuite/../../gdb/gdbserver/gdbserver --once --wrapper env TEST=1 -- :2346 /home/gdb-buildbot-2/fedora-x86-64-4/fedora-i686/build/gdb/testsuite/outputs/gdb.server/wrapper/wrapper
Process /home/gdb-buildbot-2/fedora-x86-64-4/fedora-i686/build/gdb/testsuite/outputs/gdb.server/wrapper/wrapper created; pid = 8795
Can't debug 64-bit process with 32-bit GDBserver
Exiting
target remote localhost:2346
localhost:2346: Connection timed out.
(gdb) FAIL: gdb.server/wrapper.exp: setting breakpoint at marker
See https://sourceware.org/ml/gdb-testers/2015-q3/msg01541.html
In this case, program to be debugged ("wrapper") is 32-bit but wrapper
program ("/usr/bin/env") is 64-bit, so GDBserver gets the 64-bit
target description instead of 32-bit.
The root cause of this problem is that GDBserver creates target
description too early, and the rationale of fix could be creating
target description once the GDBserver skips extra traps and inferior
stops at the first instruction of the program we want to debug. IOW,
when GDBserver skips extra traps, the inferior's tdesc is NULL, and
mywait and its callees shouldn't use inferior's tdesc, so in this
patch, we skip code that requires register access, see changes in
linux_resume_one_lwp_throw and need_step_over_p.
In linux_low_filter_event, if target description isn't initialised and
GDBserver attached the process, we create target description immediately,
because GDBserver don't have to skip extra traps for attach, IOW, it
makes no sense to use --attach and --wrapper together. Otherwise, the
process is launched by GDBserver, we keep the status pending, and return.
After GDBserver skipped extra traps in start_inferior, we call a
target_ops hook arch_setup to initialise target description there.
gdb/gdbserver:
2015-07-24 Yao Qi <yao.qi@linaro.org>
* linux-low.c (linux_arch_setup): New function.
(linux_low_filter_event): If proc->tdesc is NULL and
proc->attached is true, call the_low_target.arch_setup.
Otherwise, keep status pending, and return.
(linux_resume_one_lwp_throw): Don't call get_pc if
thread->while_stepping isn't NULL. Don't call
get_thread_regcache if proc->tdesc is NULL.
(need_step_over_p): Return 0 if proc->tdesc is NULL.
(linux_target_ops): Install arch_setup.
* server.c (start_inferior): Call the_target->arch_setup.
* target.h (struct target_ops) <arch_setup>: New field.
(target_arch_setup): New marco.
* lynx-low.c (lynx_target_ops): Update.
* nto-low.c (nto_target_ops): Update.
* spu-low.c (spu_target_ops): Update.
* win32-low.c (win32_target_ops): Update.
This patch is to refactor function start_inferior that signal_pid
is return in one place.
gdb/gdbserver:
2015-07-24 Yao Qi <yao.qi@linaro.org>
* server.c (start_inferior): Code refactor.
Sergio Durigan Junior
Simon Marchi
Pedro Alves
Joel Brobecker
Carl E. Love
Yao Qi
Marcin Kościelnicki
Josh Stone
Mike Frysinger
Patrick Palka
Antoine Tremblay
Don Breazeal
Simon Marchi