With any program under GDBserver control on LynxOS, killing
the program from the debugger (using the "kill" command) causes
GDBserver to properly kill the inferior but GDBserver then hangs.
This change of behavior occured after the following change was
applied:
commit f0ea042932e6922c90df3fd0001497d287b97677
Date: Mon Nov 30 16:05:27 2015 +0000
Subject: gdbserver: don't exit until GDB disconnects
One of the changes introduced by the commit above is that
process_serial_event no longer calls exit after handling
the vKill packet. Instead, what happens is that we wait
until captured_main finds that we no longer have any inferior
to debug, at which point it throws_quit. This (normal) exception
is then expected to propagate all the way to the exception handle
in function "main", which calls exit.
However, before the exception gets propagated, the cleanups
are first executed, and one of the cleanups in question is
detach_or_kill_for_exit_cleanup, which was put in place by
captured_main. detach_or_kill_for_exit_cleanup is basically
a wrapper around detach_or_kill_for_exit, which iterates
over all inferiors, and kills them all.
In our case, we have only one inferior, which we have already
killed during the handling for the "vKill" packet. Unfortunately,
we did not properly clean our internal data for that inferior up,
and so detach_or_kill_for_exit thinks that we still have one inferior,
and therefore tries to kill it. This results in lynx_kill being
called, doing the following:
lynx_ptrace (PTRACE_KILL, ptid, 0, 0, 0);
lynx_wait (ptid, &status, 0);
the_target->mourn (process);
The hang is caused by the call to lynx_wait, which waits for
an event from a process which does not exist...
This patch fixes the issue by enhancing lynx_mourn to clean
the threads and process list up.
gdb/gdbserver/ChangeLog:
* lynx-low.c (lynx_delete_thread_callback): New function.
(lynx_mourn): Properly delete our process and all of its
threads. Remove call to clear_inferiors.
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.
This crash is observable by debugging a threaded program on LynxOS.
On the GDB side, this is what we would see:
% gdb q
(gdb) target remote machine:4444
(gdb) break q.adb:6
(gdb) cont
[gdb hits breakpoint]
(gdb) cont
Remote connection closed <<<--- expected: [Inferior 1 (Remote target) exited normally]
On the gdbserver side, which was launched as usual:
% gdbserver --once :4444 q
Segmentation fault (core dumped)
Ooops!
The problem happens while GDB is trying to handle the thread termination
event of the thread that hit the breakpoint. It started happening after
the following change was made:
commit 96e7a1eb6d
Date: Fri Oct 16 11:08:38 2015 -0400
Subject: gdbserver: Reset current_thread when the thread is removed.
Reset current_thread and make sure 'remove_process' is used
after all associated threads have been removed first.
More precisely:
. GDBserver receives the execution-resume order;
. lynx-low resumes it succesfully, and then relies on lynx_wait_1
to wait for the next event;
. We quickly receive one, which lynx_wait_1 analyzes to be
a "thread exit" event, and therefore does...
case SIGTHREADEXIT:
remove_thread (find_thread_ptid (new_ptid));
lynx_continue (new_ptid);
goto retry;
=> remove_thread causes current_thread to be set to NULL...
(that's the recent change mentioned above)
=> ... which causes problems during lynx_continue, because
it calls lynx_resume, which calls regcache_invalidate,
which unfortunately assumes that CURRENT_THREAD is not NULL:
void
regcache_invalidate (void)
{
/* Only update the threads of the current process. */
SEGV!--> int pid = ptid_get_pid (current_thread->entry.id);
find_inferior (&all_threads, regcache_invalidate_one, &pid);
}
Since the problem at hand is caused by trying to figure out which
inferior to reset the regcache for, and since lynx_resume actually
had that info, this patch fixes the problem by introducing a new
routine called regcache_invalidate_pid, which invalidates the cache
of the given pid; and then modifies lynx_resume use that new routine
rather than relying on regcache_invalidate to invalidate the regcache
of the expected inferior.
gdb/gdbserver/ChangeLog:
* regcache.h (regcache_invalidate_pid): Add declaration.
* regcache.c (regcache_invalidate_pid): New function, extracted
from regcache_invalidate.
(regcache_invalidate): Reimplement using regcache_invalidate_pid.
Add trivial documentation comment.
* lynx-low.c: Use regcache_invalidate_pid instead of
regcache_invalidate.
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.
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.
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 implements basic support for follow-fork and detach-on-fork on
extended-remote Linux targets. Only 'fork' is supported in this patch;
'vfork' support is added n a subsequent patch. This patch depends on
the previous patches in the patch series.
Sufficient extended-remote functionality has been implemented here to pass
gdb.base/multi-forks.exp, as well as gdb.base/foll-fork.exp with the
catchpoint tests commented out. Some other fork tests fail with this
patch because it doesn't provide the architecture support needed for
watchpoint inheritance or fork catchpoints.
The implementation follows the same general structure as for the native
implementation as much as possible.
This implementation includes:
* enabling fork events in linux-low.c in initialize_low and
linux_enable_extended_features
* handling fork events in gdbserver/linux-low.c:handle_extended_wait
- when a fork event occurs in gdbserver, we must do the full creation
of the new process, thread, lwp, and breakpoint lists. This is
required whether or not the new child is destined to be
detached-on-fork, because GDB will make target calls that require all
the structures. In particular we need the breakpoint lists in order
to remove the breakpoints from a detaching child. If we are not
detaching the child we will need all these structures anyway.
- as part of this event handling we store the target_waitstatus in a new
member of the parent lwp_info structure, 'waitstatus'. This
is used to store extended event information for reporting to GDB.
- handle_extended_wait is given a return value, denoting whether the
handled event should be reported to GDB. Previously it had only
handled clone events, which were never reported.
* using a new predicate in gdbserver to control handling of the fork event
(and eventually all extended events) in linux_wait_1. The predicate,
extended_event_reported, checks a target_waitstatus.kind for an
extended ptrace event.
* implementing a new RSP 'T' Stop Reply Packet stop reason: "fork", in
gdbserver/remote-utils.c and remote.c.
* implementing new target and RSP support for target_follow_fork with
target extended-remote. (The RSP components were actually defined in
patch 1, but they see their first use here).
- remote target routine remote_follow_fork, which just sends the 'D;pid'
detach packet to detach the new fork child cleanly. We can't just
call target_detach because the data structures for the forked child
have not been allocated on the host side.
Tested on x64 Ubuntu Lucid, native, remote, extended-remote.
gdb/gdbserver/ChangeLog:
* linux-low.c (handle_extended_wait): Implement return value,
rename argument 'event_child' to 'event_lwp', handle
PTRACE_EVENT_FORK, call internal_error for unrecognized event.
(linux_low_ptrace_options): New function.
(linux_low_filter_event): Call linux_low_ptrace_options,
use different argument fo linux_enable_event_reporting,
use return value from handle_extended_wait.
(extended_event_reported): New function.
(linux_wait_1): Call extended_event_reported and set
status to report fork events.
(linux_write_memory): Add pid to debug message.
(reset_lwp_ptrace_options_callback): New function.
(linux_handle_new_gdb_connection): New function.
(linux_target_ops): Initialize new structure member.
* linux-low.h (struct lwp_info) <waitstatus>: New member.
* lynx-low.c: Initialize new structure member.
* remote-utils.c (prepare_resume_reply): Implement stop reason
"fork" for "T" stop message.
* server.c (handle_query): Call handle_new_gdb_connection.
* server.h (report_fork_events): Declare global flag.
* target.h (struct target_ops) <handle_new_gdb_connection>:
New member.
(target_handle_new_gdb_connection): New macro.
* win32-low.c: Initialize new structure member.
gdb/ChangeLog:
* linux-nat.c (linux_nat_ptrace_options): New function.
(linux_init_ptrace, wait_lwp, linux_nat_filter_event):
Call linux_nat_ptrace_options and use different argument to
linux_enable_event_reporting.
(_initialize_linux_nat): Delete call to
linux_ptrace_set_additional_flags.
* nat/linux-ptrace.c (current_ptrace_options): Rename to
supported_ptrace_options.
(additional_flags): Delete variable.
(linux_check_ptrace_features): Use supported_ptrace_options.
(linux_test_for_tracesysgood, linux_test_for_tracefork):
Likewise, and remove additional_flags check.
(linux_enable_event_reporting): Change 'attached' argument to
'options'. Use supported_ptrace_options.
(ptrace_supports_feature): Change comment. Use
supported_ptrace_options.
(linux_ptrace_set_additional_flags): Delete function.
* nat/linux-ptrace.h (linux_ptrace_set_additional_flags):
Delete function prototype.
* remote.c (remote_fork_event_p): New function.
(remote_detach_pid): New function.
(remote_detach_1): Call remote_detach_pid, don't mourn inferior
if doing detach-on-fork.
(remote_follow_fork): New function.
(remote_parse_stop_reply): Handle new "T" stop reason "fork".
(remote_pid_to_str): Print "process" strings for pid/0/0 ptids.
(init_extended_remote_ops): Initialize to_follow_fork.
This patch implements a mechanism for GDB to determine whether fork
events are supported in gdbserver. This is a preparatory patch for
remote fork and exec event support.
Two new RSP packets are defined to represent fork and vfork event
support. These packets are used just like PACKET_multiprocess_feature
to denote whether the corresponding event is supported. GDB sends
fork-events+ and vfork-events+ to gdbserver to inquire about fork
event support. If the response enables these packets, then GDB
knows that gdbserver supports the corresponding events and will
enable them.
Target functions used to query for support are included along with
each new packet.
In order for gdbserver to know whether the events are supported at the
point where the qSupported packet arrives, the code in nat/linux-ptrace.c
had to be reorganized. Previously it would test for fork/exec event
support, then enable the events using the pid of the inferior. When the
qSupported packet arrives there may not be an inferior. So the mechanism
was split into two parts: a function that checks whether the events are
supported, called when gdbserver starts up, and another that enables the
events when the inferior stops for the first time.
Another gdbserver change was to add some global variables similar to
multi_process, one per new packet. These are used to control whether
the corresponding fork events are enabled. If GDB does not inquire
about the event support in the qSupported packet, then gdbserver will
not set these "report the event" flags. If the flags are not set, the
events are ignored like they were in the past. Thus, gdbserver will
never send fork event notification to an older GDB that doesn't
recognize fork events.
Tested on Ubuntu x64, native/remote/extended-remote, and as part of
subsequent patches in the series.
gdb/gdbserver/ChangeLog:
* linux-low.c (linux_supports_fork_events): New function.
(linux_supports_vfork_events): New function.
(linux_target_ops): Initialize new structure members.
(initialize_low): Call linux_check_ptrace_features.
* lynx-low.c (lynx_target_ops): Initialize new structure
members.
* server.c (report_fork_events, report_vfork_events):
New global flags.
(handle_query): Add new features to qSupported packet and
response.
(captured_main): Initialize new global variables.
* target.h (struct target_ops) <supports_fork_events>:
New member.
<supports_vfork_events>: New member.
(target_supports_fork_events): New macro.
(target_supports_vfork_events): New macro.
* win32-low.c (win32_target_ops): Initialize new structure
members.
gdb/ChangeLog:
* nat/linux-ptrace.c (linux_check_ptrace_features): Change
from static to extern.
* nat/linux-ptrace.h (linux_check_ptrace_features): Declare.
* remote.c (anonymous enum): <PACKET_fork_event_feature,
* PACKET_vfork_event_feature>: New enumeration constants.
(remote_protocol_features): Add table entries for new packets.
(remote_query_supported): Add new feature queries to qSupported
packet.
(_initialize_remote): Exempt new packets from the requirement
to have 'set remote' commands.
GDBserver steps over breakpoint if the condition is false, but if target
doesn't support hardware single step, the step over is very simple, if
not incorrect, in linux-arm-low.c:
/* We only place breakpoints in empty marker functions, and thread locking
is outside of the function. So rather than importing software single-step,
we can just run until exit. */
static CORE_ADDR
arm_reinsert_addr (void)
{
struct regcache *regcache = get_thread_regcache (current_thread, 1);
unsigned long pc;
collect_register_by_name (regcache, "lr", &pc);
return pc;
}
and linux-mips-low.c does the same. GDBserver sets a breakpoint at the
return address of the current function, resume and wait the program hits
the breakpoint in order to achieve "breakpoint step over". What if
program hits other user breakponits during this "step over"?
It is worse if the arm/thumb interworking is considered. Nowadays,
GDBserver arm backend unconditionally inserts arm breakpoint,
/* Define an ARM-mode breakpoint; we only set breakpoints in the C
library, which is most likely to be ARM. If the kernel supports
clone events, we will never insert a breakpoint, so even a Thumb
C library will work; so will mixing EABI/non-EABI gdbserver and
application. */
(const unsigned char *) &arm_breakpoint,
(const unsigned char *) &arm_eabi_breakpoint,
note that the comments are no longer valid as C library can be compiled
in thumb mode.
When GDBserver steps over a breakpoint in arm mode function, which
returns to thumb mode, GDBserver will insert arm mode breakpoint by
mistake and the program will crash. GDBserver alone is unable to
determine the arm/thumb mode given a PC address. See how GDB does
it in arm-tdep.c:arm_pc_is_thumb.
After thinking about how to teach GDBserver inserting right breakpoint
(arm or thumb) for a while, I reconsider it from a different direction
that it may be unreasonable to run target-side conditional breakpoint for
targets without hardware single step. Pedro also pointed this out here
https://sourceware.org/ml/gdb-patches/2015-04/msg00337.html
This patch is to add a new target_ops hook
supports_conditional_breakpoints, and only reply
";ConditionalBreakpoints+" if it is true. On linux targets,
supports_conditional_breakpoints returns true if target has hardware
single step, on other targets, (win32, lynx, nto, spu), set it to NULL,
because conditional breakpoint is a linux-specific feature.
gdb/gdbserver:
2015-05-08 Yao Qi <yao.qi@linaro.org>
* linux-low.c (linux_supports_conditional_breakpoints): New
function.
(linux_target_ops): Install new target method.
* lynx-low.c (lynx_target_ops): Install NULL hook for
supports_conditional_breakpoints.
* nto-low.c (nto_target_ops): Likewise.
* spu-low.c (spu_target_ops): Likewise.
* win32-low.c (win32_target_ops): Likewise.
* server.c (handle_query): Check
target_supports_conditional_breakpoints.
* target.h (struct target_ops) <supports_conditional_breakpoints>:
New field.
(target_supports_conditional_breakpoints): New macro.
I forgot to update these target_ops instances when I added these new
hooks.
I confirmed mingw32-w64 builds again at least.
gdb/gdbserver/ChangeLog:
2015-03-05 Pedro Alves <palves@redhat.com>
* lynx-low.c (lynx_target_ops): Install NULL hooks for
stopped_by_sw_breakpoint, supports_stopped_by_sw_breakpoint,
stopped_by_hw_breakpoint, supports_stopped_by_hw_breakpoint.
* nto-low.c (nto_target_ops): Likewise.
* spu-low.c (spu_target_ops): Likewise.
* win32-low.c (win32_target_ops): Likewise.
This patch renames symbols that happen to have names which are
reserved keywords in C++.
Most of this was generated with Tromey's cxx-conversion.el script.
Some places where later hand massaged a bit, to fix formatting, etc.
And this was rebased several times meanwhile, along with re-running
the script, so re-running the script from scratch probably does not
result in the exact same output. I don't think that matters anyway.
gdb/
2015-02-27 Tom Tromey <tromey@redhat.com>
Pedro Alves <palves@redhat.com>
Rename symbols whose names are reserved C++ keywords throughout.
gdb/gdbserver/
2015-02-27 Tom Tromey <tromey@redhat.com>
Pedro Alves <palves@redhat.com>
Rename symbols whose names are reserved C++ keywords throughout.
Currently, when we receive a request to single-step one single thread
(Eg, when single-stepping out of a breakpoint), we use the
PTRACE_SINGLESTEP pthread request, which does single-step
the corresponding thread, but also resumes execution of all
other threads in the inferior.
This causes problems when debugging programs where another thread
receives multiple debug events while trying to single-step a specific
thread out of a breakpoint (with infrun traces turned on):
(gdb) continue
Continuing.
infrun: clear_proceed_status_thread (Thread 126)
[...]
infrun: clear_proceed_status_thread (Thread 142)
[...]
infrun: clear_proceed_status_thread (Thread 146)
infrun: clear_proceed_status_thread (Thread 125)
infrun: proceed (addr=0xffffffff, signal=GDB_SIGNAL_DEFAULT, step=0)
infrun: resume (step=1, signal=GDB_SIGNAL_0), trap_expected=1, current thread [Thread 142] at 0x10684838
infrun: wait_for_inferior ()
infrun: target_wait (-1, status) =
infrun: 42000 [Thread 146],
infrun: status->kind = stopped, signal = GDB_SIGNAL_REALTIME_34
infrun: infwait_normal_state
infrun: TARGET_WAITKIND_STOPPED
infrun: stop_pc = 0x10a187f4
infrun: context switch
infrun: Switching context from Thread 142 to Thread 146
infrun: random signal (GDB_SIGNAL_REALTIME_34)
infrun: switching back to stepped thread
infrun: Switching context from Thread 146 to Thread 142
infrun: resume (step=1, signal=GDB_SIGNAL_0), trap_expected=1, current thread [Thread 142] at 0x10684838
infrun: prepare_to_wait
[...handling of similar events for threads 145, 144 and 143 snipped...]
infrun: prepare_to_wait
infrun: target_wait (-1, status) =
infrun: 42000 [Thread 146],
infrun: status->kind = stopped, signal = GDB_SIGNAL_REALTIME_34
infrun: infwait_normal_state
infrun: TARGET_WAITKIND_STOPPED
infrun: stop_pc = 0x10a187f4
infrun: context switch
infrun: Switching context from Thread 142 to Thread 146
../../src/gdb/inline-frame.c:339: internal-error: skip_inline_frames: Assertion `find_inline_frame_state (ptid) == NULL' failed.
What happens is that GDB keeps sending requests to resume one specific
thread, and keeps receiving debugging events for other threads.
Things break down when the one of the other threads receives a debug
event for the second time (thread 146 in the example above).
This patch fixes the problem by making sure that only one thread
gets resumed, thus preventing the other threads from generating
an unexpected event.
gdb/gdbserver/ChangeLog:
* lynx-low.c (lynx_resume): Use PTRACE_SINGLESTEP_ONE if N == 1.
Remove FIXME comment about assumption about N.
We noticed the following error on ppc-lynx178, using just about
any program:
(gdb) tar remote mytarget:4444
Remote debugging using mytarget:4444
0x000100c8 in _start ()
(gdb) b try
Breakpoint 1 at 0x10844: file try.adb, line 11.
(gdb) cont
Continuing.
!!!-> Cannot remove breakpoints because program is no longer writable.
!!!-> Further execution is probably impossible.
Breakpoint 1, try () at try.adb:11
11 Local : Integer := 18;
And, of course, trying to continue yielded the expected outcome:
(gdb) c
Continuing.
warning: Error removing breakpoint 1
Cannot remove breakpoints because program is no longer writable.
Further execution is probably impossible.
It turns out that the problem is caused by an intentional test
against a variable with an undefined value. After GDB receives
notification of the inferior stopping, it tries to remove the
breakpoint by sending a memory-write packet ("X10844,4:9 ").
This leads us to lynx_write_memory, where it tries to split
the memory-write into chunks of 4 bytes. And, in order to handle
writes which are not aligned on word boundaries, we have the
following code:
if (skip > 0 || truncate > 0)
/* We need to read the memory at this address in order to preserve
the data that we are not overwriting. */
lynx_read_memory (addr, (unsigned char *) &buf, xfer_size);
if (errno)
return errno;
(the comment explains what the code is about).
Unfortunately, the not-so-glaring error that we've made here is
that we're checking ERRNO regardless of whether we've called
lynx_read_memory. In our case, because we are writing 4 bytes
aligned on a word boundary, we do not call lynx_read_memory and
therefore test an ERRNO with an undefined value.
gdb/gdbserver/ChangeLog:
* lynx-low.c (lynx_write_memory): Put lynx_read_memory and
corresponding ERRNO check in same block.
GDB has a function named "current_inferior" and gdbserver has a global
variable named "current_inferior", but the two are not equivalent;
indeed, gdbserver does not have any real equivalent of what GDB calls
an inferior. What gdbserver's "current_inferior" is actually pointing
to is a structure describing the current thread. This commit renames
current_inferior as current_thread in gdbserver to clarify this. It
also renames the function "set_desired_inferior" to "set_desired_thread"
and renames various local variables from foo_inferior to foo_thread.
gdb/gdbserver/ChangeLog:
* inferiors.h (current_inferior): Renamed as...
(current_thread): New variable. All uses updated.
* linux-low.c (get_pc): Renamed saved_inferior as saved_thread.
(maybe_move_out_of_jump_pad): Likewise.
(cancel_breakpoint): Likewise.
(linux_low_filter_event): Likewise.
(wait_for_sigstop): Likewise.
(linux_resume_one_lwp): Likewise.
(need_step_over_p): Likewise.
(start_step_over): Likewise.
(linux_stabilize_threads): Renamed save_inferior as saved_thread.
* linux-x86-low.c (x86_linux_update_xmltarget): Likewise.
* proc-service.c (ps_lgetregs): Renamed reg_inferior as reg_thread
and save_inferior as saved_thread.
* regcache.c (get_thread_regcache): Renamed saved_inferior as
saved_thread.
(regcache_invalidate_thread): Likewise.
* remote-utils.c (prepare_resume_reply): Likewise.
* thread-db.c (thread_db_get_tls_address): Likewise.
(disable_thread_event_reporting): Likewise.
(remove_thread_event_breakpoints): Likewise.
* tracepoint.c (gdb_agent_about_to_close): Renamed save_inferior
as saved_thread.
* target.h (set_desired_inferior): Renamed as...
(set_desired_thread): New declaration. All uses updated.
* server.c (myresume): Updated comment to reference thread instead
of inferior.
(handle_serial_event): Likewise.
(handle_target_event): Likewise.
This patch fixes hardware breakpoint regressions exposed by my fix for
"PR breakpoints/7143 - Watchpoint does not trigger when first set", at
https://sourceware.org/ml/gdb-patches/2014-03/msg00167.html
The testsuite caught them on Linux/x86_64, at least. gdb.sum:
gdb.sum:
FAIL: gdb.base/hbreak2.exp: next over recursive call
FAIL: gdb.base/hbreak2.exp: backtrace from factorial(5.1)
FAIL: gdb.base/hbreak2.exp: continue until exit at recursive next test
gdb.log:
(gdb) next
Program received signal SIGTRAP, Trace/breakpoint trap.
factorial (value=4) at ../../../src/gdb/testsuite/gdb.base/break.c:113
113 if (value > 1) { /* set breakpoint 7 here */
(gdb) FAIL: gdb.base/hbreak2.exp: next over recursive call
Actually, that patch just exposed a latent issue to "breakpoints
always-inserted off" mode, not really caused it. After that patch,
GDB no longer removes breakpoints at each internal event, thus making
some scenarios behave like breakpoint always-inserted on. The bug is
easy to trigger with always-inserted on.
The issue is that since the target-side breakpoint conditions support,
if the stub/server supports evaluating breakpoint conditions on the
target side, then GDB is sending duplicate Zx packets to the target
without removing them before, and GDBserver is not really expecting
that for Z packets other than Z0/z0. E.g., with "set breakpoint
always-inserted on" and "set debug remote 1":
(gdb) b main
Sending packet: $m410943,1#ff...Packet received: 48
Breakpoint 4 at 0x410943: file ../../../src/gdb/gdbserver/server.c, line 3028.
Sending packet: $Z0,410943,1#48...Packet received: OK
^^^^^^^^^^^^
(gdb) b main
Note: breakpoint 4 also set at pc 0x410943.
Sending packet: $m410943,1#ff...Packet received: 48
Breakpoint 5 at 0x410943: file ../../../src/gdb/gdbserver/server.c, line 3028.
Sending packet: $Z0,410943,1#48...Packet received: OK
^^^^^^^^^^^^
(gdb) b main
Note: breakpoints 4 and 5 also set at pc 0x410943.
Sending packet: $m410943,1#ff...Packet received: 48
Breakpoint 6 at 0x410943: file ../../../src/gdb/gdbserver/server.c, line 3028.
Sending packet: $Z0,410943,1#48...Packet received: OK
^^^^^^^^^^^^
(gdb) del
Delete all breakpoints? (y or n) y
Sending packet: $Z0,410943,1#48...Packet received: OK
Sending packet: $Z0,410943,1#48...Packet received: OK
Sending packet: $z0,410943,1#68...Packet received: OK
And for Z1, similarly:
(gdb) hbreak main
Sending packet: $m410943,1#ff...Packet received: 48
Hardware assisted breakpoint 4 at 0x410943: file ../../../src/gdb/gdbserver/server.c, line 3028.
Sending packet: $Z1,410943,1#49...Packet received: OK
^^^^^^^^^^^^
Packet Z1 (hardware-breakpoint) is supported
(gdb) hbreak main
Note: breakpoint 4 also set at pc 0x410943.
Sending packet: $m410943,1#ff...Packet received: 48
Hardware assisted breakpoint 5 at 0x410943: file ../../../src/gdb/gdbserver/server.c, line 3028.
Sending packet: $Z1,410943,1#49...Packet received: OK
^^^^^^^^^^^^
(gdb) hbreak main
Note: breakpoints 4 and 5 also set at pc 0x410943.
Sending packet: $m410943,1#ff...Packet received: 48
Hardware assisted breakpoint 6 at 0x410943: file ../../../src/gdb/gdbserver/server.c, line 3028.
Sending packet: $Z1,410943,1#49...Packet received: OK
^^^^^^^^^^^^
(gdb) del
Delete all breakpoints? (y or n) y
Sending packet: $Z1,410943,1#49...Packet received: OK
^^^^^^^^^^^^
Sending packet: $Z1,410943,1#49...Packet received: OK
^^^^^^^^^^^^
Sending packet: $z1,410943,1#69...Packet received: OK
^^^^^^^^^^^^
So GDB sent a bunch of Z1 packets, and then when finally removing the
breakpoint, only one z1 packet was sent. On the GDBserver side (with
monitor set debug-hw-points 1), in the Z1 case, we see:
$ ./gdbserver :9999 ./gdbserver
Process ./gdbserver created; pid = 8629
Listening on port 9999
Remote debugging from host 127.0.0.1
insert_watchpoint (addr=410943, len=1, type=instruction-execute):
CONTROL (DR7): 00000101 STATUS (DR6): 00000000
DR0: addr=0x410943, ref.count=1 DR1: addr=0x0, ref.count=0
DR2: addr=0x0, ref.count=0 DR3: addr=0x0, ref.count=0
insert_watchpoint (addr=410943, len=1, type=instruction-execute):
CONTROL (DR7): 00000101 STATUS (DR6): 00000000
DR0: addr=0x410943, ref.count=2 DR1: addr=0x0, ref.count=0
DR2: addr=0x0, ref.count=0 DR3: addr=0x0, ref.count=0
insert_watchpoint (addr=410943, len=1, type=instruction-execute):
CONTROL (DR7): 00000101 STATUS (DR6): 00000000
DR0: addr=0x410943, ref.count=3 DR1: addr=0x0, ref.count=0
DR2: addr=0x0, ref.count=0 DR3: addr=0x0, ref.count=0
insert_watchpoint (addr=410943, len=1, type=instruction-execute):
CONTROL (DR7): 00000101 STATUS (DR6): 00000000
DR0: addr=0x410943, ref.count=4 DR1: addr=0x0, ref.count=0
DR2: addr=0x0, ref.count=0 DR3: addr=0x0, ref.count=0
insert_watchpoint (addr=410943, len=1, type=instruction-execute):
CONTROL (DR7): 00000101 STATUS (DR6): 00000000
DR0: addr=0x410943, ref.count=5 DR1: addr=0x0, ref.count=0
DR2: addr=0x0, ref.count=0 DR3: addr=0x0, ref.count=0
remove_watchpoint (addr=410943, len=1, type=instruction-execute):
CONTROL (DR7): 00000101 STATUS (DR6): 00000000
DR0: addr=0x410943, ref.count=4 DR1: addr=0x0, ref.count=0
DR2: addr=0x0, ref.count=0 DR3: addr=0x0, ref.count=0
That's one insert_watchpoint call for each Z1 packet, and then one
remove_watchpoint call for the z1 packet. Notice how ref.count
increased for each insert_watchpoint call, and then in the end, after
GDB told GDBserver to forget about the hardware breakpoint, GDBserver
ends with the the first debug register still with ref.count=4! IOW,
the hardware breakpoint is left armed on the target, while on the GDB
end it's gone. If the program happens to execute 0x410943 afterwards,
then the CPU traps, GDBserver reports the trap to GDB, and GDB not
having a breakpoint set at that address anymore, reports to the user a
spurious SIGTRAP.
This is exactly what is happening in the hbreak2.exp test, though in
that case, it's a shared library event that triggers a
breakpoint_re_set, when breakpoints are still inserted (because
nowadays GDB doesn't remove breakpoints while handling internal
events), and that recreates breakpoint locations, which likewise
forces breakpoint reinsertion and Zx packet resends...
That is a lot of bogus Zx duplication that should possibly be
addressed on the GDB side. GDB resends Zx packets because the way to
change the target-side condition, is to resend the breakpoint to the
server with the new condition. (That's an option in the packet: e.g.,
"Z1,410943,1;X3,220027" for "hbreak main if 0". The packets in the
examples above are shorter because the breakpoints don't have
conditions attached). GDB doesn't remove the breakpoint first before
reinserting it because that'd be bad for non-stop, as it'd open a
window where the inferior could miss the breakpoint. The conditions
actually haven't changed between the resends, but GDB isn't smart
enough to realize that.
(TBC, if the target doesn't support target-side conditions, then GDB
doesn't trigger these resends (init_bp_location calls
mark_breakpoint_location_modified, and that does nothing if condition
evaluation is on the host side. The resends are caused by the
'loc->condition_changed = condition_modified.' line.)
But, even if GDB was made smarter, GDBserver should really still
handle the resends anyway. So target-side conditions also aren't
really to blame. The documentation of the Z/z packets says:
"To avoid potential problems with duplicate packets, the operations
should be implemented in an idempotent way."
As such, we may want to fix GDB, but we should definitely fix
GDBserver. The fix is a prerequisite for target-side conditions on
hardware breakpoints anyway (and while at it, on watchpoints too).
GDBserver indeed already treats duplicate Z0 packets in an idempotent
way. mem-break.c has the concept of high-level and low-level
breakpoints, somewhat similar to GDB's split of breakpoints vs
breakpoint locations, and keeps track of multiple breakpoints
referencing the same address/location, for the case of an internal
GDBserver breakpoint or a tracepoint being set at the same address as
a GDB breakpoint. But, it only allows GDB to ever contribute one
reference to a software breakpoint location. IOW, if gdbserver sees a
Z0 packet for the same address where it already had a GDB breakpoint
set, then GDBserver won't create another high-level GDB breakpoint.
However, mem-break.c only tracks GDB Z0 breakpoints. The same logic
should apply to all kinds of Zx packets. Currently, gdbserver passes
down each duplicate Zx (other than Z0) request directly to the
target->insert_point routine. The x86 watchpoint support itself
refcounts watchpoint / hw breakpoint requests, to handle overlapping
watchpoints, and save debug registers. But that code doesn't (and
really shouldn't) handle the duplicate requests, assuming that for
each insert there will be a corresponding remove.
So the fix is to generalize mem-break.c to track all kinds of Zx
breakpoints, and filter out duplicates. As mentioned, this ends up
adding support for target-side conditions on hardware breakpoints and
watchpoints too (though GDB itself doesn't support the latter yet).
Probably the least obvious change in the patch is that it kind of
turns the breakpoint insert/remove APIs inside out. Before, the
target methods were only called for GDB breakpoints. The internal
breakpoint set/delete methods inserted memory breakpoints directly
bypassing the insert/remove target methods. That's not good when the
target should use a debug API to set software breakpoints, instead of
relying on GDBserver patching memory with breakpoint instructions, as
is the case of NTO.
Now removal/insertion of all kinds of breakpoints/watchpoints, either
internal, or from GDB, always go through the target methods. The
insert_point/remove_point methods no longer get passed a Z packet
type, but an internal/raw breakpoint type. They're also passed a
pointer to the raw breakpoint itself (note that's still opaque outside
mem-break.c), so that insert_memory_breakpoint /
remove_memory_breakpoint have access to the breakpoint's shadow
buffer. I first tried passing down a new structure based on GDB's
"struct bp_target_info" (actually with that name exactly), but then
decided against it as unnecessary complication.
As software/memory breakpoints work by poking at memory, when setting
a GDB Z0 breakpoint (but not internal breakpoints, as those can assume
the conditions are already right), we need to tell the target to
prepare to access memory (which on Linux means stop threads). If that
operation fails, we need to return error to GDB. Seeing an error, if
this is the first breakpoint of that type that GDB tries to insert,
GDB would then assume the breakpoint type is supported, but it may
actually not be. So we need to check whether the type is supported at
all before preparing to access memory. And to solve that, the patch
adds a new target->supports_z_point_type method that is called before
actually trying to insert the breakpoint.
Other than that, hopefully the change is more or less obvious.
New test added that exercises the hbreak2.exp regression in a more
direct way, without relying on a breakpoint re-set happening before
main is reached.
Tested by building GDBserver for:
aarch64-linux-gnu
arm-linux-gnueabihf
i686-pc-linux-gnu
i686-w64-mingw32
m68k-linux-gnu
mips-linux-gnu
mips-uclinux
nios2-linux-gnu
powerpc-linux-gnu
sh-linux-gnu
tilegx-unknown-linux-gnu
x86_64-redhat-linux
x86_64-w64-mingw32
And also regression tested on x86_64 Fedora 20.
gdb/gdbserver/
2014-05-20 Pedro Alves <palves@redhat.com>
* linux-aarch64-low.c (aarch64_insert_point)
(aarch64_remove_point): No longer check whether the type is
supported here. Adjust to new interface.
(the_low_target): Install aarch64_supports_z_point_type as
supports_z_point_type method.
* linux-arm-low.c (raw_bkpt_type_to_arm_hwbp_type): New function.
(arm_linux_hw_point_initialize): Take an enum raw_bkpt_type
instead of a Z packet char. Adjust.
(arm_supports_z_point_type): New function.
(arm_insert_point, arm_remove_point): Adjust to new interface.
(the_low_target): Install arm_supports_z_point_type.
* linux-crisv32-low.c (cris_supports_z_point_type): New function.
(cris_insert_point, cris_remove_point): Adjust to new interface.
Don't check whether the type is supported here.
(the_low_target): Install cris_supports_z_point_type.
* linux-low.c (linux_supports_z_point_type): New function.
(linux_insert_point, linux_remove_point): Adjust to new interface.
* linux-low.h (struct linux_target_ops) <insert_point,
remove_point>: Take an enum raw_bkpt_type instead of a char. Add
raw_breakpoint pointer parameter.
<supports_z_point_type>: New method.
* linux-mips-low.c (mips_supports_z_point_type): New function.
(mips_insert_point, mips_remove_point): Adjust to new interface.
Use mips_supports_z_point_type.
(the_low_target): Install mips_supports_z_point_type.
* linux-ppc-low.c (the_low_target): Install NULL as
supports_z_point_type method.
* linux-s390-low.c (the_low_target): Install NULL as
supports_z_point_type method.
* linux-sparc-low.c (the_low_target): Install NULL as
supports_z_point_type method.
* linux-x86-low.c (x86_supports_z_point_type): New function.
(x86_insert_point): Adjust to new insert_point interface. Use
insert_memory_breakpoint. Adjust to new
i386_low_insert_watchpoint interface.
(x86_remove_point): Adjust to remove_point interface. Use
remove_memory_breakpoint. Adjust to new
i386_low_remove_watchpoint interface.
(the_low_target): Install x86_supports_z_point_type.
* lynx-low.c (lynx_target_ops): Install NULL as
supports_z_point_type callback.
* nto-low.c (nto_supports_z_point_type): New.
(nto_insert_point, nto_remove_point): Adjust to new interface.
(nto_target_ops): Install nto_supports_z_point_type.
* mem-break.c: Adjust intro comment.
(struct raw_breakpoint) <raw_type, size>: New fields.
<inserted>: Update comment.
<shlib_disabled>: Delete field.
(enum bkpt_type) <gdb_breakpoint>: Delete value.
<gdb_breakpoint_Z0, gdb_breakpoint_Z1, gdb_breakpoint_Z2,
gdb_breakpoint_Z3, gdb_breakpoint_Z4>: New values.
(raw_bkpt_type_to_target_hw_bp_type): New function.
(find_enabled_raw_code_breakpoint_at): New function.
(find_raw_breakpoint_at): New type and size parameters. Use them.
(insert_memory_breakpoint): New function, based off
set_raw_breakpoint_at.
(remove_memory_breakpoint): New function.
(set_raw_breakpoint_at): Reimplement.
(set_breakpoint): New, based on set_breakpoint_at.
(set_breakpoint_at): Reimplement.
(delete_raw_breakpoint): Go through the_target->remove_point
instead of assuming memory breakpoints.
(find_gdb_breakpoint_at): Delete.
(Z_packet_to_bkpt_type, Z_packet_to_raw_bkpt_type): New functions.
(find_gdb_breakpoint): New function.
(set_gdb_breakpoint_at): Delete.
(z_type_supported): New function.
(set_gdb_breakpoint_1): New function, loosely based off
set_gdb_breakpoint_at.
(check_gdb_bp_preconditions, set_gdb_breakpoint): New functions.
(delete_gdb_breakpoint_at): Delete.
(delete_gdb_breakpoint_1): New function, loosely based off
delete_gdb_breakpoint_at.
(delete_gdb_breakpoint): New function.
(clear_gdb_breakpoint_conditions): Rename to ...
(clear_breakpoint_conditions): ... this. Don't handle a NULL
breakpoint.
(add_condition_to_breakpoint): Make static.
(add_breakpoint_condition): Take a struct breakpoint pointer
instead of an address. Adjust.
(gdb_condition_true_at_breakpoint): Rename to ...
(gdb_condition_true_at_breakpoint_z_type): ... this, and add
z_type parameter.
(gdb_condition_true_at_breakpoint): Reimplement.
(add_breakpoint_commands): Take a struct breakpoint pointer
instead of an address. Adjust.
(gdb_no_commands_at_breakpoint): Rename to ...
(gdb_no_commands_at_breakpoint_z_type): ... this. Add z_type
parameter. Return true if no breakpoint was found. Change debug
output.
(gdb_no_commands_at_breakpoint): Reimplement.
(run_breakpoint_commands): Rename to ...
(run_breakpoint_commands_z_type): ... this. Add z_type parameter,
and change return type to boolean.
(run_breakpoint_commands): New function.
(gdb_breakpoint_here): Also check for Z1 breakpoints.
(uninsert_raw_breakpoint): Don't try to reinsert a disabled
breakpoint. Go through the_target->remove_point instead of
assuming memory breakpoint.
(uninsert_breakpoints_at, uninsert_all_breakpoints): Uninsert
software and hardware breakpoints.
(reinsert_raw_breakpoint): Go through the_target->insert_point
instead of assuming memory breakpoint.
(reinsert_breakpoints_at, reinsert_all_breakpoints): Reinsert
software and hardware breakpoints.
(check_breakpoints, breakpoint_here, breakpoint_inserted_here):
Check both software and hardware breakpoints.
(validate_inserted_breakpoint): Assert the breakpoint is a
software breakpoint. Set the inserted flag to -1 instead of
setting shlib_disabled.
(delete_disabled_breakpoints): Adjust.
(validate_breakpoints): Only validate software breakpoints.
Adjust to inserted flag change.
(check_mem_read, check_mem_write): Skip breakpoint types other
than software breakpoints. Adjust to inserted flag change.
* mem-break.h (enum raw_bkpt_type): New enum.
(raw_breakpoint, struct process_info): Forward declare.
(Z_packet_to_target_hw_bp_type): Delete declaration.
(raw_bkpt_type_to_target_hw_bp_type, Z_packet_to_raw_bkpt_type)
(set_gdb_breakpoint, delete_gdb_breakpoint)
(clear_breakpoint_conditions): New declarations.
(set_gdb_breakpoint_at, clear_gdb_breakpoint_conditions): Delete.
(breakpoint_inserted_here): Update comment.
(add_breakpoint_condition, add_breakpoint_commands): Replace
address parameter with a breakpoint pointer parameter.
(gdb_breakpoint_here): Update comment.
(delete_gdb_breakpoint_at): Delete.
(insert_memory_breakpoint, remove_memory_breakpoint): Declare.
* server.c (process_point_options): Take a struct breakpoint
pointer instead of an address. Adjust.
(process_serial_event) <Z/z packets>: Use set_gdb_breakpoint and
delete_gdb_breakpoint.
* spu-low.c (spu_target_ops): Install NULL as
supports_z_point_type method.
* target.h: Include mem-break.h.
(struct target_ops) <prepare_to_access_memory>: Update comment.
<supports_z_point_type>: New field.
<insert_point, remove_point>: Take an enum raw_bkpt_type argument
instead of a char. Also take a raw breakpoint pointer.
* win32-arm-low.c (the_low_target): Install NULL as
supports_z_point_type.
* win32-i386-low.c (i386_supports_z_point_type): New function.
(i386_insert_point, i386_remove_point): Adjust to new interface.
(the_low_target): Install i386_supports_z_point_type.
* win32-low.c (win32_supports_z_point_type): New function.
(win32_insert_point, win32_remove_point): Adjust to new interface.
(win32_target_ops): Install win32_supports_z_point_type.
* win32-low.h (struct win32_target_ops):
<supports_z_point_type>: New method.
<insert_point, remove_point>: Take an enum raw_bkpt_type argument
instead of a char. Also take a raw breakpoint pointer.
gdb/testsuite/
2014-05-20 Pedro Alves <palves@redhat.com>
* gdb.base/break-idempotent.c: New file.
* gdb.base/break-idempotent.exp: New file.
The current implementation is forgetting to populate the thread list
when attaching to the process. This results in an incomplete list of
threads when debugging a threaded program.
Unfortunately, as the added comments hints, there appears to be
no way of getting the list of threads via ptrace, other than by
spawning the "ps" command, and parsing its output. Not great,
but it appears to be the best we can do.
gdb/gdbserver/ChangeLog:
* lynx-low.c (lynx_add_threads_after_attach): New function.
(lynx_attach): Remove call to add_thread. Add call to
lynx_add_threads_after_attach instead.
This patch makes GDBserver support multi-process + biarch.
Currently, if you're debugging more than one process at once with a
single gdbserver (in extended-remote mode), then all processes must
have the same architecture (e.g., 64-bit vs 32-bit). Otherwise, you
see this:
Added inferior 2
[Switching to inferior 2 [<null>] (<noexec>)]
Reading symbols from /home/pedro/gdb/tests/main32...done.
Temporary breakpoint 2 at 0x4004cf: main. (2 locations)
Starting program: /home/pedro/gdb/tests/main32
warning: Selected architecture i386 is not compatible with reported target architecture i386:x86-64
warning: Architecture rejected target-supplied description
Remote 'g' packet reply is too long: 000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000090cfffff0000000000000000000000000000000000000000000000000000000000020000000000000000000000000000000000000000000000000000000000000000000000000000b042f7460000000000020000230000002b0000002b0000002b000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000007f03000000000000ffff0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000801f00003b0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
... etc, etc ...
Even though the process was running a 32-bit program, GDBserver sent
back to GDB a register set in 64-bit layout.
A patch (http://sourceware.org/ml/gdb-patches/2012-11/msg00228.html) a
while ago made GDB track a target_gdbarch per inferior, and as
consequence, fetch a target description per-inferior. This patch is
the GDBserver counterpart, that makes GDBserver keep track of each
process'es XML target description and register layout. So in the
example above, GDBserver will send the correct register set in 32-bit
layout to GDB.
A new "struct target_desc" object (tdesc for short) is added, that
holds the target description and register layout information about
each process. Each `struct process_info' holds a pointer to a target
description. The regcache also gains a pointer to a target
description, mainly for convenience, and parallel with GDB (and
possible future support for programs that flip processor modes).
The low target's arch_setup routines are responsible for setting the
process'es correct tdesc. This isn't that much different to how
things were done before, except that instead of detecting the inferior
process'es architecture and calling the corresponding
init_registers_FOO routine, which would change the regcache layout
globals and recreate the threads' regcaches, the regcache.c globals
are gone, and the init_registers_$BAR routines now each initialize a
separate global struct target_desc object (one for each arch variant
GDBserver supports), and so all the init_registers_$BAR routines that
are built into GDBserver are called early at GDBserver startup time
(similarly to how GDB handles its built-in target descriptions), and
then the arch_setup routine is responsible for making
process_info->tdesc point to one of these target description globals.
The regcache module is all parameterized to get the regcache's layout
from the tdesc object instead of the old register_bytes, etc. globals.
The threads' regcaches are now created lazily. The old scheme where
we created each of them when we added a new thread doesn't work
anymore, because we add the main thread/lwp before we see it stop for
the first time, and it is only when we see the thread stop for the
first time that we have a chance of determining the inferior's
architecture (through the_low_target.arch_setup). Therefore when we
add the main thread we don't know which architecture/tdesc its
regcache should have.
This patch makes the gdb.multi/multi-arch.exp test now pass against
(extended-remote) GDBserver. It currently fails, without this patch.
The IPA also uses the regcache, so it gains a new global struct
target_desc pointer, which points at the description of the process it
is loaded in.
Re. the linux-low.c & friends changes. Since the register map
etc. may differ between processes (64-bit vs 32-bit) etc., the
linux_target_ops num_regs, regmap and regset_bitmap data fields are no
longer sufficient. A new method is added in their place that returns
a pointer to a new struct that includes all info linux-low.c needs to
access registers of the current inferior.
The patch/discussion that originally introduced
linux-low.c:disabled_regsets mentions that the disabled_regsets set
may be different per mode (in a biarch setup), and indeed that is
cleared whenever we start a new (first) inferior, so that global is
moved as well behind the new `struct regs_info'.
On the x86 side:
I simply replaced the i387-fp.c:num_xmm_registers global with a check
for 64-bit or 32-bit process, which is equivalent to how the global
was set. This avoided coming up with some more general mechanism that
would work for all targets that use this module (GNU/Linux, Windows,
etc.).
Tested:
GNU/Linux IA64
GNU/Linux MIPS64
GNU/Linux PowerPC (Fedora 16)
GNU/Linux s390x (Fedora 16)
GNU/Linux sparc64 (Debian)
GNU/Linux x86_64, -m64 and -m32 (Fedora 17)
Cross built, and smoke tested:
i686-w64-mingw32, under Wine.
GNU/Linux TI C6x, by Yao Qi.
Cross built but otherwise not tested:
aarch64-linux-gnu
arm-linux-gnu
m68k-linux
nios2-linux-gnu
sh-linux-gnu
spu
tilegx-unknown-linux-gnu
Completely untested:
GNU/Linux Blackfin
GNU/Linux CRIS
GNU/Linux CRISv32
GNU/Linux TI Xtensa
GNU/Linux M32R
LynxOS
QNX NTO
gdb/gdbserver/
2013-06-07 Pedro Alves <palves@redhat.com>
* Makefile.in (OBS): Add tdesc.o.
(IPA_OBJS): Add tdesc-ipa.o.
(tdesc-ipa.o): New rule.
* ax.c (gdb_eval_agent_expr): Adjust register_size call to new
interface.
* linux-low.c (new_inferior): Delete.
(disabled_regsets, num_regsets): Delete.
(linux_add_process): Adjust to set the new per-process
new_inferior flag.
(linux_detach_one_lwp): Adjust to call regcache_invalidate_thread.
(linux_wait_for_lwp): Adjust. Only call arch_setup if the event
was a stop. When calling arch_setup, switch the current inferior
to the thread that got an event.
(linux_resume_one_lwp): Adjust to call regcache_invalidate_thread.
(regsets_fetch_inferior_registers)
(regsets_store_inferior_registers): New regsets_info parameter.
Adjust to use it.
(linux_register_in_regsets): New regs_info parameter. Adjust to
use it.
(register_addr, fetch_register, store_register): New usrregs_info
parameter. Adjust to use it.
(usr_fetch_inferior_registers, usr_store_inferior_registers): New
parameter regs_info. Adjust to use it.
(linux_fetch_registers): Get the current inferior's regs_info, and
adjust to use it.
(linux_store_registers): Ditto.
[HAVE_LINUX_REGSETS] (initialize_regsets_info): New.
(initialize_low): Don't initialize the target_regsets here. Call
initialize_low_arch.
* linux-low.h (target_regsets): Delete declaration.
(struct regsets_info): New.
(struct usrregs_info): New.
(struct regs_info): New.
(struct process_info_private) <new_inferior>: New field.
(struct linux_target_ops): Delete the num_regs, regmap, and
regset_bitmap fields. New field regs_info.
[HAVE_LINUX_REGSETS] (initialize_regsets_info): Declare.
* i387-fp.c (num_xmm_registers): Delete.
(i387_cache_to_fsave, i387_fsave_to_cache): Adjust find_regno
calls to new interface.
(i387_cache_to_fxsave, i387_cache_to_xsave, i387_fxsave_to_cache)
(i387_xsave_to_cache): Adjust find_regno calls to new interface.
Infer the number of xmm registers from the regcache's target
description.
* i387-fp.h (num_xmm_registers): Delete.
* inferiors.c (add_thread): Don't install the thread's regcache
here.
* proc-service.c (gregset_info): Fetch the current inferior's
regs_info. Adjust to use it.
* regcache.c: Include tdesc.h.
(register_bytes, reg_defs, num_registers)
(gdbserver_expedite_regs): Delete.
(get_thread_regcache): If the thread doesn't have a regcache yet,
create one, instead of aborting gdbserver.
(regcache_invalidate_one): Rename to ...
(regcache_invalidate_thread): ... this.
(regcache_invalidate_one): New.
(regcache_invalidate): Only invalidate registers of the current
process.
(init_register_cache): Add target_desc parameter, and use it.
(new_register_cache): Ditto. Assert the target description has a
non zero registers_size.
(regcache_cpy): Add assertions. Adjust.
(realloc_register_cache, set_register_cache): Delete.
(registers_to_string, registers_from_string): Adjust.
(find_register_by_name, find_regno, find_register_by_number)
(register_cache_size): Add target_desc parameter, and use it.
(free_register_cache_thread, free_register_cache_thread_one)
(regcache_release, register_cache_size): New.
(register_size): Add target_desc parameter, and use it.
(register_data, supply_register, supply_register_zeroed)
(supply_regblock, supply_register_by_name, collect_register)
(collect_register_as_string, collect_register_by_name): Adjust.
* regcache.h (struct target_desc): Forward declare.
(struct regcache) <tdesc>: New field.
(init_register_cache, new_register_cache): Add target_desc
parameter.
(regcache_invalidate_thread): Declare.
(regcache_invalidate_one): Delete declaration.
(regcache_release): Declare.
(find_register_by_number, register_cache_size, register_size)
(find_regno): Add target_desc parameter.
(gdbserver_expedite_regs, gdbserver_xmltarget): Delete
declarations.
* remote-utils.c: Include tdesc.h.
(outreg, prepare_resume_reply): Adjust.
* server.c: Include tdesc.h.
(gdbserver_xmltarget): Delete declaration.
(get_features_xml, process_serial_event): Adjust.
* server.h [IN_PROCESS_AGENT] (struct target_desc): Forward
declare.
(struct process_info) <tdesc>: New field.
(ipa_tdesc): Declare.
* tdesc.c: New file.
* tdesc.h: New file.
* tracepoint.c: Include tdesc.h.
[IN_PROCESS_AGENT] (ipa_tdesc): Define.
(get_context_regcache): Adjust to pass ipa_tdesc down.
(do_action_at_tracepoint): Adjust to get the register cache size
from the context regcache's description.
(traceframe_walk_blocks): Adjust to get the register cache size
from the current trace frame's description.
(traceframe_get_pc): Adjust to get current trace frame's
description and pass it down.
(gdb_collect): Adjust to get the register cache size from the
IPA's description.
* linux-amd64-ipa.c (tdesc_amd64_linux): Declare.
(gdbserver_xmltarget): Delete.
(initialize_low_tracepoint): Set the ipa's target description.
* linux-i386-ipa.c (tdesc_i386_linux): Declare.
(initialize_low_tracepoint): Set the ipa's target description.
* linux-x86-low.c: Include tdesc.h.
[__x86_64__] (is_64bit_tdesc): New.
(ps_get_thread_area, x86_get_thread_area): Use it.
(i386_cannot_store_register): Rename to ...
(x86_cannot_store_register): ... this. Use is_64bit_tdesc.
(i386_cannot_fetch_register): Rename to ...
(x86_cannot_fetch_register): ... this. Use is_64bit_tdesc.
(x86_fill_gregset, x86_store_gregset): Adjust register_size calls
to new interface.
(target_regsets): Rename to ...
(x86_regsets): ... this.
(x86_get_pc, x86_set_pc): Adjust register_size calls to new
interface.
(x86_siginfo_fixup): Use is_64bit_tdesc.
[__x86_64__] (tdesc_amd64_linux, tdesc_amd64_avx_linux)
(tdesc_x32_avx_linux, tdesc_x32_linux)
(tdesc_i386_linux, tdesc_i386_mmx_linux, tdesc_i386_avx_linux):
Declare.
(x86_linux_update_xmltarget): Delete.
(I386_LINUX_XSAVE_XCR0_OFFSET): Define.
(have_ptrace_getfpxregs, have_ptrace_getregset): New.
(AMD64_LINUX_USER64_CS): New.
(x86_linux_read_description): New, based on
x86_linux_update_xmltarget.
(same_process_callback): New.
(x86_arch_setup_process_callback): New.
(x86_linux_update_xmltarget): New.
(x86_regsets_info): New.
(amd64_linux_regs_info): New.
(i386_linux_usrregs_info): New.
(i386_linux_regs_info): New.
(x86_linux_regs_info): New.
(x86_arch_setup): Reimplement.
(x86_install_fast_tracepoint_jump_pad): Use is_64bit_tdesc.
(x86_emit_ops): Ditto.
(the_low_target): Adjust. Install x86_linux_regs_info,
x86_cannot_fetch_register, and x86_cannot_store_register.
(initialize_low_arch): New.
* linux-ia64-low.c (tdesc_ia64): Declare.
(ia64_fetch_register): Adjust.
(ia64_usrregs_info, regs_info): New globals.
(ia64_regs_info): New function.
(the_low_target): Adjust.
(initialize_low_arch): New function.
* linux-sparc-low.c (tdesc_sparc64): Declare.
(sparc_fill_gregset_to_stack, sparc_store_gregset_from_stack):
Adjust.
(sparc_arch_setup): New function.
(sparc_regsets_info, sparc_usrregs_info, regs_info): New globals.
(the_low_target): Adjust.
(initialize_low_arch): New function.
* linux-ppc-low.c (tdesc_powerpc_32l, tdesc_powerpc_altivec32l)
(tdesc_powerpc_cell32l, tdesc_powerpc_vsx32l)
(tdesc_powerpc_isa205_32l, tdesc_powerpc_isa205_altivec32l)
(tdesc_powerpc_isa205_vsx32l, tdesc_powerpc_e500l)
(tdesc_powerpc_64l, tdesc_powerpc_altivec64l)
(tdesc_powerpc_cell64l, tdesc_powerpc_vsx64l)
(tdesc_powerpc_isa205_64l, tdesc_powerpc_isa205_altivec64l)
(tdesc_powerpc_isa205_vsx64l): Declare.
(ppc_cannot_store_register, ppc_collect_ptrace_register)
(ppc_supply_ptrace_register, parse_spufs_run, ppc_get_pc)
(ppc_set_pc, ppc_get_hwcap): Adjust.
(ppc_usrregs_info): Forward declare.
(!__powerpc64__) ppc_regmap_adjusted: New global.
(ppc_arch_setup): Adjust to the current process'es target
description.
(ppc_fill_vsxregset, ppc_store_vsxregset, ppc_fill_vrregset)
(ppc_store_vrregset, ppc_fill_evrregset, ppc_store_evrregse)
(ppc_store_evrregset): Adjust.
(target_regsets): Rename to ...
(ppc_regsets): ... this, and make static.
(ppc_usrregs_info, ppc_regsets_info, regs_info): New globals.
(ppc_regs_info): New function.
(the_low_target): Adjust.
(initialize_low_arch): New function.
* linux-s390-low.c (tdesc_s390_linux32, tdesc_s390_linux32v1)
(tdesc_s390_linux32v2, tdesc_s390_linux64, tdesc_s390_linux64v1)
(tdesc_s390_linux64v2, tdesc_s390x_linux64, tdesc_s390x_linux64v1)
(tdesc_s390x_linux64v2): Declare.
(s390_collect_ptrace_register, s390_supply_ptrace_register)
(s390_fill_gregset, s390_store_last_break): Adjust.
(target_regsets): Rename to ...
(s390_regsets): ... this, and make static.
(s390_get_pc, s390_set_pc): Adjust.
(s390_get_hwcap): New target_desc parameter, and use it.
[__s390x__] (have_hwcap_s390_high_gprs): New global.
(s390_arch_setup): Adjust to set the current process'es target
description. Don't adjust the regmap.
(s390_usrregs_info, s390_regsets_info, regs_info): New globals.
[__s390x__] (s390_usrregs_info_3264, s390_regsets_info_3264)
(regs_info_3264): New globals.
(s390_regs_info): New function.
(the_low_target): Adjust.
(initialize_low_arch): New function.
* linux-mips-low.c (tdesc_mips_linux, tdesc_mips_dsp_linux)
(tdesc_mips64_linux, tdesc_mips64_dsp_linux): Declare.
[__mips64] (init_registers_mips_linux)
(init_registers_mips_dsp_linux): Delete defines.
[__mips64] (tdesc_mips_linux, tdesc_mips_dsp_linux): New defines.
(have_dsp): New global.
(mips_read_description): New, based on mips_arch_setup.
(mips_arch_setup): Reimplement.
(get_usrregs_info): New function.
(mips_cannot_fetch_register, mips_cannot_store_register)
(mips_get_pc, mips_set_pc, mips_fill_gregset, mips_store_gregset)
(mips_fill_fpregset, mips_store_fpregset): Adjust.
(target_regsets): Rename to ...
(mips_regsets): ... this, and make static.
(mips_regsets_info, mips_dsp_usrregs_info, mips_usrregs_info)
(dsp_regs_info, regs_info): New globals.
(mips_regs_info): New function.
(the_low_target): Adjust.
(initialize_low_arch): New function.
* linux-arm-low.c (tdesc_arm, tdesc_arm_with_iwmmxt)
(tdesc_arm_with_vfpv2, tdesc_arm_with_vfpv3, tdesc_arm_with_neon):
Declare.
(arm_fill_vfpregset, arm_store_vfpregset): Adjust.
(arm_read_description): New, with bits factored from
arm_arch_setup.
(arm_arch_setup): Reimplement.
(target_regsets): Rename to ...
(arm_regsets): ... this, and make static.
(arm_regsets_info, arm_usrregs_info, regs_info): New globals.
(arm_regs_info): New function.
(the_low_target): Adjust.
(initialize_low_arch): New function.
* linux-m68k-low.c (tdesc_m68k): Declare.
(target_regsets): Rename to ...
(m68k_regsets): ... this, and make static.
(m68k_regsets_info, m68k_usrregs_info, regs_info): New globals.
(m68k_regs_info): New function.
(m68k_arch_setup): New function.
(the_low_target): Adjust.
(initialize_low_arch): New function.
* linux-sh-low.c (tdesc_sharch): Declare.
(target_regsets): Rename to ...
(sh_regsets): ... this, and make static.
(sh_regsets_info, sh_usrregs_info, regs_info): New globals.
(sh_regs_info, sh_arch_setup): New functions.
(the_low_target): Adjust.
(initialize_low_arch): New function.
* linux-bfin-low.c (tdesc_bfin): Declare.
(bfin_arch_setup): New function.
(bfin_usrregs_info, regs_info): New globals.
(bfin_regs_info): New function.
(the_low_target): Adjust.
(initialize_low_arch): New function.
* linux-cris-low.c (tdesc_cris): Declare.
(cris_arch_setup): New function.
(cris_usrregs_info, regs_info): New globals.
(cris_regs_info): New function.
(the_low_target): Adjust.
(initialize_low_arch): New function.
* linux-cris-low.c (tdesc_crisv32): Declare.
(cris_arch_setup): New function.
(cris_regsets_info, cris_usrregs_info, regs_info): New globals.
(cris_regs_info): New function.
(the_low_target): Adjust.
(initialize_low_arch): New function.
* linux-m32r-low.c (tdesc_m32r): Declare.
(m32r_arch_setup): New function.
(m32r_usrregs_info, regs_info): New globals.
(m32r_regs_info): Adjust.
(initialize_low_arch): New function.
* linux-tic6x-low.c (tdesc_tic6x_c64xp_linux)
(tdesc_tic6x_c64x_linux, tdesc_tic6x_c62x_linux): Declare.
(tic6x_usrregs_info): Forward declare.
(tic6x_read_description): New function, based on ...
(tic6x_arch_setup): ... this. Reimplement.
(target_regsets): Rename to ...
(tic6x_regsets): ... this, and make static.
(tic6x_regsets_info, tic6x_usrregs_info, regs_info): New globals.
(tic6x_regs_info): New function.
(the_low_target): Adjust.
(initialize_low_arch): New function.
* linux-xtensa-low.c (tdesc_xtensa): Declare.
(xtensa_fill_gregset, xtensa_store_gregset): Adjust.
(target_regsets): Rename to ...
(xtensa_regsets): ... this, and make static.
(xtensa_regsets_info, xtensa_usrregs_info, regs_info): New
globals.
(xtensa_arch_setup, xtensa_regs_info): New functions.
(the_low_target): Adjust.
(initialize_low_arch): New function.
* linux-nios2-low.c (tdesc_nios2_linux): Declare.
(nios2_arch_setup): Set the current process'es tdesc.
(target_regsets): Rename to ...
(nios2_regsets): ... this.
(nios2_regsets_info, nios2_usrregs_info, regs_info): New globals.
(nios2_regs_info): New function.
(the_low_target): Adjust.
(initialize_low_arch): New function.
* linux-aarch64-low.c (tdesc_aarch64): Declare.
(aarch64_arch_setup): Set the current process'es tdesc.
(target_regsets): Rename to ...
(aarch64_regsets): ... this.
(aarch64_regsets_info, aarch64_usrregs_info, regs_info): New globals.
(aarch64_regs_info): New function.
(the_low_target): Adjust.
(initialize_low_arch): New function.
* linux-tile-low.c (tdesc_tilegx, tdesc_tilegx32): Declare
globals.
(target_regsets): Rename to ...
(tile_regsets): ... this.
(tile_regsets_info, tile_usrregs_info, regs_info): New globals.
(tile_regs_info): New function.
(tile_arch_setup): Set the current process'es tdesc.
(the_low_target): Adjust.
(initialize_low_arch): New function.
* spu-low.c (tdesc_spu): Declare.
(spu_create_inferior, spu_attach): Set the new process'es tdesc.
* win32-arm-low.c (tdesc_arm): Declare.
(arm_arch_setup): New function.
(the_low_target): Install arm_arch_setup instead of
init_registers_arm.
* win32-i386-low.c (tdesc_i386, tdesc_amd64): Declare.
(init_windows_x86): Rename to ...
(i386_arch_setup): ... this. Set `win32_tdesc'.
(the_low_target): Adjust.
* win32-low.c (win32_tdesc): New global.
(child_add_thread): Don't create the thread cache here.
(do_initial_child_stuff): Set the new process'es tdesc.
* win32-low.h (struct target_desc): Forward declare.
(win32_tdesc): Declare.
* lynx-i386-low.c (tdesc_i386): Declare global.
(lynx_i386_arch_setup): Set `lynx_tdesc'.
* lynx-low.c (lynx_tdesc): New global.
(lynx_add_process): Set the new process'es tdesc.
* lynx-low.h (struct target_desc): Forward declare.
(lynx_tdesc): Declare global.
* lynx-ppc-low.c (tdesc_powerpc_32): Declare global.
(lynx_ppc_arch_setup): Set `lynx_tdesc'.
* nto-low.c (nto_tdesc): New global.
(do_attach): Set the new process'es tdesc.
* nto-low.h (struct target_desc): Forward declare.
(nto_tdesc): Declare.
* nto-x86-low.c (tdesc_i386): Declare.
(nto_x86_arch_setup): Set `nto_tdesc'.
gdb/
2013-06-07 Pedro Alves <palves@redhat.com>
* regformats/regdat.sh: Output #include tdesc.h. Make globals
static. Output a global target description pointer.
(init_registers_${name}): Adjust to initialize a
target description structure.
On ppc-lynx178, resuming the execution of a program after hitting
a breakpoint sometimes triggers a spurious SIG61 event:
(gdb) cont
Continuing.
Program received signal SIG61, Real-time event 61.
[Switching to Thread 39]
0x10002324 in a_test.task1 (<_task>=0x3ffff774) at a_test.adb:30
30 select -- Task 1
From this point on, continuing again lets the signal kill the program.
Using "signal 0" or configuring GDB to discard the signal does not
help either, as the program immediately reports the same signal again.
What happens is the following:
- GDB sends a single-step order to gdbserver: $vCont;s:31
This tells GDBserver to do a step using thread 0x31=49.
GDBserver does the step, and thread 49 receives the SIGTRAP
indicating that the step has finished.
- GDB then sends a "continue", but this time does not specify
which thread to continue: $vCont;c
GDBserver uses an arbitrary thread's ptid to resume the program's
execution (the current_inferior's ptid was chosen for that).
See lynx-low.c:lynx_resume:
if (ptid_equal (ptid, minus_one_ptid))
ptid = thread_to_gdb_id (current_inferior);
So far on all LynxOS platforms, this has been good enough. But
not so on LynxOS 178. If the ptid used to resume the execution
is not the same as the thread that did the step, we get the weird
signal.
This patch fixes the problem by saving the ptid of the thread
that last caused an event, received during a call to waitpid.
The ptid is saved in per-process private data.
gdb/gdbserver/ChangeLog:
* lynx-low.c (struct process_info_private): New type.
(lynx_add_process): New function.
(lynx_create_inferior, lynx_attach): Replace calls to
add_process by calls to lynx_add_process.
(lynx_resume): If PTID is null, then try using
current_process()->private->last_wait_event_ptid.
Add comments.
(lynx_clear_inferiors): Delete. The contents of that function
has been inlined in lynx_mourn;
(lynx_wait_1): Save the ptid in the process's private data.
(lynx_mourn): Free the process' private data. Replace call
to lynx_clear_inferiors by call to clear_inferiors.
... following Pedro's advice of using a temporary macro.
gdb/gdbserver/ChangeLog:
* lynx-low.c (ptrace_request_to_str): Define a temporary
macro and use it to simplify this function's implementation.
Before this patch, the ptid passed to lynx_resume was completely
ignored, and we used the current_inferior. This resulted in trying
to resume the inferior execution using the wrong ptid after having
received a thread create/exit event, because the inferior_ptid
was still set to the ptid prior to receiving the signal.
gdb/gdbserver/ChangeLog:
* lynx-low.c (lynx_resume): Use the resume_info parameter
to determine the ptid for the lynx_ptrace call, unless
it is equal to minus_one_ptid, in which case we use the
ptid of the current_inferior.
(lynx_wait_1): After having received a thread create/exit
event, resume the inferior's execution using the signaling
thread's ptid, rather than the old ptid.
Two modifications:
1. The addition of 2013 to the copyright year range for every file;
2. The use of a single year range, instead of potentially multiple
year ranges, as approved by the FSF.
We use this ptrace request when handling SIGTRAP signals,
and without this change, the debug trances show:
PTRACE (<unknown-request>, ...
This patch fixes this.
gdb/gdbserver/ChangeLog:
* lynx-low.c (ptrace_request_to_str): Add handling for
PTRACE_GETTRACESIG.
LynxOS 178 does not define this macro.
gdb/gdbserver/ChangeLog:
* lynx-low.c (ptrace_request_to_str): Do not handle
PTRACE_GETTHREADLIST if this macro does not exist.
ARI fixes: move gdb_wait and gdb_stat headers to common subdirectory.
* gdb_stat.h: Delete. Moved to common directory.
* common/gdb_stat.h: New file.
* gdb_wait.h: Delete. Moved to common directory.
* common/gdb_wait.h: New file.
* Makefile.in (H_FILES_NO_SRC): Adapt to new header
location.
* contrib/ari/gdb_ari.sh (wait.h rule): Adapt to new gdb_wait.h
location.
(stat.h rule): Adapt to new gdb_stat.h location.
* common/linux-osdata.c: Include "gdb_stat.h" header instead of
<sys/stat.h> header.
* common/linux-ptrace.c: Include "gdb_wait.h" header instead of
<sys/wait.h> header.
gdbserver ChangeLog entry:
2012-11-15 Pierre Muller <muller@sourceware.org>
* configure.ac (AC_CHECK_HEADERS): Add wait.h header.
* config.in: Regenerate.
* configure: Regenerate.
* linux-low.c: Use "gdb_stat.h" header instead of <sys/stat.h> header.
Use "gdb_wait.h" header instead of <sys/wait.h> header.
* lynx-low.c: Use "gdb_wait.h" header instead of <sys/wait.h> header.
* remote-utils.c: Use "gdb_stat.h" header instead of <sys/stat.h>
header.
* server.c: Remove HAVE_WAIT_H conditional. Use "gdb_wait.h" header
instead of <sys/wait.h> header.
* spu-low.c: Use "gdb_wait.h" header instead of <sys/wait.h> header.
Some of the PTRACE_ macros/values were removed in LynxOS 5.x.
Since we have not use them so far, the chances that we will use them
one day are very small. So I decided to delete them.
gdb/gdbserver/ChangeLog:
* lynx-low.c (ptrace_request_to_str): Remove handling for
request values that have been removed in LynxOS 5.x.
This is one of the changes needed in order to build gdbserver on
LynxOS 5.x.
Really interesting: On LynxOS 4.x, there is a #warning when sys/ptrace.h
is used (explaining that ptrace.h will be used instead), whereas this
file was removed from LynxOS 5.x. The contents of sys/ptrace.h on 4.x
(or at least the meat of it):
#if defined(__GNUC__) || defined(__GNUG__)
#if !defined(__NO_INCLUDE_WARN__)
#warning Using <ptrace.h> instead of <sys/ptrace.h>
#endif /* defined(__NO_INCLUDE_WARN__) */
#endif /* defined(__GNUC__) || defined(__GNUG__) */
#include <ptrace.h>
The fix I went for, for now, is to just include <sys/ptrace.h>
unconditionally. I could have done some configury, but we already
have to build with -D__NO_INCLUDE_WARN__ to avoid the warnings
anyway, and that's unvoidable, due to system includes themselves
including the "wrong" header file.
Since <sys/ptrace.h> seems to be the choice that was made for LynxOS,
and since it works to include it on LynxOS 4.x, I think that's the simplest
solution.
gdb/gdbserver/ChangeLog:
* lynx-low.c, lynx-ppc-low.c: Include <sys/ptrace.h> instead of
<ptrace.h>
This patch adds support for powerpc-lynxos.
gdbserver/ChangeLog:
* gdbserver/lynx-low.c, gdbserver/lynx-low.h,
gdbserver/lynx-ppc-low.c: New files.
* Makefile.in (lynx_low_h): New variable.
(lynx-low.o, lynx-ppc-low.o): New rules.
* configure.ac: On LynxOS, link with -lnetinet.
* configure.srv: Add handling of powerpc-*-lynxos* targets.
* configure: regenerate.
Joel Brobecker