This patch implements the architecture-specific pieces of follow-fork
for remote and extended-remote Linux targets, which in the current
implementation copyies the parent's debug register state into the new
child's data structures. This is required for x86, arm, aarch64, and
mips.
This follows the native implementation as closely as possible by
implementing a new linux_target_ops function 'new_fork', which is
analogous to 'linux_nat_new_fork' in linux-nat.c. In gdbserver, the debug
registers are stored in the process list, instead of an
architecture-specific list, so the function arguments are process_info
pointers instead of an lwp_info and a pid as in the native implementation.
In the MIPS implementation the debug register mirror is stored differently
from x86, ARM, and aarch64, so instead of doing a simple structure assignment
I had to clone the list of watchpoint structures.
Tested using gdb.threads/watchpoint-fork.exp on x86, and ran manual tests
on a MIPS board and an ARM board. Aarch64 hasn't been tested.
gdb/gdbserver/ChangeLog:
* linux-aarch64-low.c (aarch64_linux_new_fork): New function.
(the_low_target) <new_fork>: Initialize new member.
* linux-arm-low.c (arm_new_fork): New function.
(the_low_target) <new_fork>: Initialize new member.
* linux-low.c (handle_extended_wait): Call new target function
new_fork.
* linux-low.h (struct linux_target_ops) <new_fork>: New member.
* linux-mips-low.c (mips_add_watchpoint): New function
extracted from mips_insert_point.
(the_low_target) <new_fork>: Initialize new member.
(mips_linux_new_fork): New function.
(mips_insert_point): Call mips_add_watchpoint.
* linux-x86-low.c (x86_linux_new_fork): New function.
(the_low_target) <new_fork>: Initialize new member.
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 commit changes the signature of linux_target_ops.new_thread in
gdbserver to match that used in GDB's equivalent.
gdb/gdbserver/ChangeLog:
* linux-low.h (linux_target_ops) <new_thread>: Changed signature.
* linux-arm-low.c (arm_new_thread): Likewise.
* linux-aarch64-low.c (aarch64_linux_new_thread): Likewise.
* linux-mips-low.c (mips_linux_new_thread): Likewise.
* linux-x86-low.c (x86_linux_new_thread): Likewise.
* linux-low.c (add_lwp): Update the_low_target.new_thread call.
Both GDB and gdbserver had linux_stop_lwp functions with identical
declarations. This commit moves these to nat/linux-nat.h to allow
shared code to use the function.
gdb/ChangeLog:
* linux-nat.h (linux_stop_lwp): Move declaration to...
* nat/linux-nat.h (linux_stop_lwp): New declaration.
gdb/gdbserver/ChangeLog:
* linux-low.h (linux_stop_lwp): Remove declaration.
This commit introduces a new function, iterate_over_lwps, that
shared Linux code can use to call a function for each LWP that
matches certain criteria. This function already existed in GDB
and was in use by GDB's various low-level Linux x86 debug register
setters. An equivalent was written for gdbserver and gdbserver's
low-level Linux x86 debug register setters were modified to use
it.
gdb/ChangeLog:
* linux-nat.h: Include nat/linux-nat.h.
(iterate_over_lwps): Move declaration to nat/linux-nat.h.
* nat/linux-nat.h (struct lwp_info): New forward declaration.
(iterate_over_lwps_ftype): New typedef.
(iterate_over_lwps): New declaration.
* linux-nat.h (iterate_over_lwps): Update comment. Use
iterate_over_lwps_ftype. Update callback return value check.
gdb/gdbserver/ChangeLog:
* linux-low.h: Include nat/linux-nat.h.
* linux-low.c (iterate_over_lwps_args): New structure.
(iterate_over_lwps_filter): New function.
(iterate_over_lwps): Likewise.
* linux-x86-low.c (update_debug_registers_callback):
Update signature to what iterate_over_lwps expects.
Remove PID check that iterate_over_lwps now performs.
(x86_dr_low_set_addr): Use iterate_over_lwps.
(x86_dr_low_set_control): Likewise.
This patch applies the same starvation avoidance improvements of the
previous patch to the Linux gdbserver side.
Without this, the test added by the following commit
(gdb.threads/non-stop-fair-events.exp) always fails with time outs.
gdb/gdbserver/
2015-01-09 Pedro Alves <palves@redhat.com>
* linux-low.c (step_over_bkpt): Move higher up in the file.
(handle_extended_wait): Don't store the stop_pc here.
(get_stop_pc): Adjust comments and rename to ...
(check_stopped_by_breakpoint): ... this. Record whether the LWP
stopped for a software breakpoint or hardware breakpoint.
(thread_still_has_status_pending_p): New function.
(status_pending_p_callback): Use
thread_still_has_status_pending_p. If the event is no longer
interesting, resume the LWP.
(handle_tracepoints): Add assert.
(maybe_move_out_of_jump_pad): Remove cancel_breakpoints call.
(wstatus_maybe_breakpoint): New function.
(cancel_breakpoint): Delete function.
(check_stopped_by_watchpoint): New function, factored out from
linux_low_filter_event.
(lp_status_maybe_breakpoint): Delete function.
(linux_low_filter_event): Remove filter_ptid argument.
Leave thread group exits pending here. Store the LWP's stop PC.
Always leave events pending.
(linux_wait_for_event_filtered): Pull all events out of the
kernel, and leave them all pending.
(count_events_callback, select_event_lwp_callback): Consider all
events.
(cancel_breakpoints_callback, linux_cancel_breakpoints): Delete.
(select_event_lwp): Only give preference to the stepping LWP in
all-stop mode. Adjust comments.
(ignore_event): New function.
(linux_wait_1): Delete 'retry' label. Use ignore_event. Remove
references to cancel_breakpoints. Adjust to renames. Also give
equal priority to all LWPs that have had events in non-stop mode.
If reporting a software breakpoint event, unadjust the LWP's PC.
(linux_wait): If linux_wait_1 returned an ignored event, retry.
(stuck_in_jump_pad_callback, move_out_of_jump_pad_callback):
Adjust.
(linux_resume_one_lwp): Store the LWP's PC. Adjust.
(resume_status_pending_p): Use thread_still_has_status_pending_p.
(linux_stopped_by_watchpoint): Adjust.
(linux_target_ops): Remove reference to linux_cancel_breakpoints.
* linux-low.h (enum lwp_stop_reason): New.
(struct lwp_info) <stop_pc>: Adjust comment.
<stopped_by_watchpoint>: Delete field.
<stop_reason>: New field.
* linux-x86-low.c (x86_linux_prepare_to_resume): Adjust.
* mem-break.c (software_breakpoint_inserted_here)
(hardware_breakpoint_inserted_here): New function.
* mem-break.h (software_breakpoint_inserted_here)
(hardware_breakpoint_inserted_here): Declare.
* target.h (struct target_ops) <cancel_breakpoints>: Remove field.
(cancel_breakpoints): Delete.
* tracepoint.c (clear_installed_tracepoints, stop_tracing)
(upload_fast_traceframes): Remove references to
cancel_breakpoints.
... instead of relying on libthread_db.
I wrote a test that attaches to a program that constantly spawns
short-lived threads, which exposed several issues. This is one of
them.
On Linux, we need to attach to all threads of a process (thread group)
individually. We currently rely on libthread_db to list the threads,
but that is problematic, because libthread_db relies on reading data
structures out of the inferior (which may well be corrupted). If
threads are being created or exiting just while we try to attach, we
may trip on inconsistencies in the inferior's thread list. To work
around that, when we see a seemingly corrupt list, we currently retry
a few times:
static void
thread_db_find_new_threads_2 (ptid_t ptid, int until_no_new)
{
...
if (until_no_new)
{
/* Require 4 successive iterations which do not find any new threads.
The 4 is a heuristic: there is an inherent race here, and I have
seen that 2 iterations in a row are not always sufficient to
"capture" all threads. */
...
That heuristic may well fail, and when it does, we end up with threads
in the program that aren't under GDB's control. That's obviously bad
and results in quite mistifying failures, like e.g., the process dying
for seeminly no reason when a thread that wasn't attached trips on a
breakpoint.
There's really no reason to rely on libthread_db for this nowadays
when we have /proc mounted. In that case, which is the usual case, we
can list the LWPs from /proc/PID/task/. In fact, GDBserver is already
doing this. The patch factors out that code that knows to walk the
task/ directory out of GDBserver, and makes GDB use it too.
Like GDBserver, the patch makes GDB attach to LWPs and _not_ wait for
them to stop immediately. Instead, we just tag the LWP as having an
expected stop. Because we can only set the ptrace options when the
thread stops, we need a new flag in the lwp structure to keep track of
whether we've already set the ptrace options, just like in GDBserver.
Note that nothing issues any ptrace command to the threads between the
PTRACE_ATTACH and the stop, so this is safe (unlike one scenario
described in gdbserver's linux-low.c).
When we attach to a program that has threads exiting while we attach,
it's easy to race with a thread just exiting as we try to attach to
it, like:
#1 - get current list of threads
#2 - attach to each listed thread
#3 - ooops, attach failed, thread is already gone
As this is pretty normal, we shouldn't be issuing a scary warning in
step #3.
When #3 happens, PTRACE_ATTACH usually fails with ESRCH, but sometimes
we'll see EPERM as well. That happens when the kernel still has the
thread in its task list, but the thread is marked as dead.
Unfortunately, EPERM is ambiguous and we'll get it also on other
scenarios where the thread isn't dead, and in those cases, it's useful
to get a warning. To distiguish the cases, when we get an EPERM
failure, we open /proc/PID/status, and check the thread's state -- if
the /proc file no longer exists, or the state is "Z (Zombie)" or "X
(Dead)", we ignore the EPERM error silently; otherwise, we'll warn.
Unfortunately, there seems to be a kernel race here. Sometimes I get
EPERM, and then the /proc state still indicates "R (Running)"... If
we wait a bit and retry, we do end up seeing X or Z state, or get an
ESRCH. I thought of making GDB retry the attach a few times, but even
with a 500ms wait and 4 retries, I still see the warning sometimes. I
haven't been able to identify the kernel path that causes this yet,
but in any case, it looks like a kernel bug to me. As this just
results failure to suppress a warning that we've been printing since
about forever anyway, I'm just making the test cope with it, and issue
an XFAIL.
gdb/gdbserver/
2015-01-09 Pedro Alves <palves@redhat.com>
* linux-low.c (linux_attach_fail_reason_string): Move to
nat/linux-ptrace.c, and rename.
(linux_attach_lwp): Update comment.
(attach_proc_task_lwp_callback): New function.
(linux_attach): Adjust to rename and use
linux_proc_attach_tgid_threads.
(linux_attach_fail_reason_string): Delete declaration.
gdb/
2015-01-09 Pedro Alves <palves@redhat.com>
* linux-nat.c (attach_proc_task_lwp_callback): New function.
(linux_nat_attach): Use linux_proc_attach_tgid_threads.
(wait_lwp, linux_nat_filter_event): If not set yet, set the lwp's
ptrace option flags.
* linux-nat.h (struct lwp_info) <must_set_ptrace_flags>: New
field.
* nat/linux-procfs.c: Include <dirent.h>.
(linux_proc_get_int): New parameter "warn". Handle it.
(linux_proc_get_tgid): Adjust.
(linux_proc_get_tracerpid): Rename to ...
(linux_proc_get_tracerpid_nowarn): ... this.
(linux_proc_pid_get_state): New function, factored out from
(linux_proc_pid_has_state): ... this. Add new parameter "warn"
and handle it.
(linux_proc_pid_is_gone): New function.
(linux_proc_pid_is_stopped): Adjust.
(linux_proc_pid_is_zombie_maybe_warn)
(linux_proc_pid_is_zombie_nowarn): New functions.
(linux_proc_pid_is_zombie): Use
linux_proc_pid_is_zombie_maybe_warn.
(linux_proc_attach_tgid_threads): New function.
* nat/linux-procfs.h (linux_proc_get_tgid): Update comment.
(linux_proc_get_tracerpid): Rename to ...
(linux_proc_get_tracerpid_nowarn): ... this, and update comment.
(linux_proc_pid_is_gone): New declaration.
(linux_proc_pid_is_zombie): Update comment.
(linux_proc_pid_is_zombie_nowarn): New declaration.
(linux_proc_attach_lwp_func): New typedef.
(linux_proc_attach_tgid_threads): New declaration.
* nat/linux-ptrace.c (linux_ptrace_attach_fail_reason): Adjust to
use nowarn functions.
(linux_ptrace_attach_fail_reason_string): Move here from
gdbserver/linux-low.c and rename.
(ptrace_supports_feature): If the current ptrace options are not
known yet, check them now, instead of asserting.
* nat/linux-ptrace.h (linux_ptrace_attach_fail_reason_string):
Declare.
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.
On Linux, we need to explicitly ptrace attach to all lwps of a
process. Because GDB might not be connected yet when an attach is
requested, and thus it may not be possible to activate thread_db, as
that requires access to symbols (IOW, gdbserver --attach), a while ago
we make linux_attach loop over the lwps as listed by /proc/PID/task to
find the lwps to attach to.
linux_attach_lwp_1 has:
...
if (initial)
/* If lwp is the tgid, we handle adding existing threads later.
Otherwise we just add lwp without bothering about any other
threads. */
ptid = ptid_build (lwpid, lwpid, 0);
else
{
/* Note that extracting the pid from the current inferior is
safe, since we're always called in the context of the same
process as this new thread. */
int pid = pid_of (current_inferior);
ptid = ptid_build (pid, lwpid, 0);
}
That "safe" comment referred to linux_attach_lwp being called by
thread-db.c. But this was clearly missed when a new call to
linux_attach_lwp_1 was added to linux_attach. As a result,
current_inferior will be set to some random process, and non-initial
lwps of the second inferior get assigned the pid of the wrong
inferior. E.g., in the case of attaching to two inferiors, for the
second inferior (and so on), non-initial lwps of the second inferior
get assigned the pid of the first inferior. This doesn't trigger on
the first inferior, when current_inferior is NULL, add_thread switches
the current inferior to the newly added thread.
Rather than making linux_attach switch current_inferior temporarily
(thus avoiding further reliance on global state), or making
linux_attach_lwp_1 get the tgid from /proc, which add extra syscalls,
and will be wrong in case of the user having originally attached
directly to a non-tgid lwp, and then that lwp spawning new clones (the
ptid.pid field of further new clones should be the same as the
original lwp's pid, which is not the tgid), we note that callers of
linux_attach_lwp/linux_attach_lwp_1 always have the right pid handy
already, so they can pass it down along with the lwpid.
The only other reason for the "initial" parameter is to error out
instead of warn in case of attach failure, when we're first attaching
to a process. There are only three callers of
linux_attach_lwp/linux_attach_lwp_1, and each wants to print a
different warn/error string, so we can just move the error/warn out of
linux_attach_lwp_1 to the callers, thus getting rid of the "initial"
parameter.
There really nothing gdbserver-specific about attaching to two
threaded processes, so this adds a new test under gdb.multi/. The
test passes cleanly against the native GNU/Linux target, but
fails/triggers the bug against GDBserver (before the patch), with the
native-extended-remote board (as plain remote doesn't support
multi-process).
Tested on x86_64 Fedora 17, with the native-extended-gdbserver board.
gdb/gdbserver/
2014-04-25 Pedro Alves <palves@redhat.com>
PR server/16255
* linux-low.c (linux_attach_fail_reason_string): New function.
(linux_attach_lwp): Delete.
(linux_attach_lwp_1): Rename to ...
(linux_attach_lwp): ... this. Take a ptid instead of a pid as
argument. Remove "initial" parameter. Return int instead of
void. Don't error or warn here.
(linux_attach): Adjust to call linux_attach_lwp. Call error on
failure to attach to the tgid. Call warning when failing to
attach to an lwp.
* linux-low.h (linux_attach_lwp): Take a ptid instead of a pid as
argument. Remove "initial" parameter. Return int instead of
void. Don't error or warn here.
(linux_attach_fail_reason_string): New declaration.
* thread-db.c (attach_thread): Adjust to linux_attach_lwp's
interface change. Use linux_attach_fail_reason_string.
gdb/
2014-04-25 Pedro Alves <palves@redhat.com>
PR server/16255
* common/linux-ptrace.c (linux_ptrace_attach_warnings): Rename to ...
(linux_ptrace_attach_fail_reason): ... this. Remove "warning: "
and newline from built string.
* common/linux-ptrace.h (linux_ptrace_attach_warnings): Rename to ...
(linux_ptrace_attach_fail_reason): ... this.
* linux-nat.c (linux_nat_attach): Adjust to use
linux_ptrace_attach_fail_reason.
gdb/testsuite/
2014-04-25 Simon Marchi <simon.marchi@ericsson.com>
Pedro Alves <palves@redhat.com>
PR server/16255
* gdb.multi/multi-attach.c: New file.
* gdb.multi/multi-attach.exp: New file.
* gdbthread.h (add_thread): Change result type to struct thread_info *.
* inferiors.c (add_thread): Change result type to struct thread_info *.
All callers updated.
(add_lwp): Call add_thread here instead of in callers.
All callers updated.
* linux-low.h (get_lwp_thread): Rewrite.
(struct lwp_info): New member "thread".
This speeds up gdbserver attach in non-stop mode because now get_lwp_thread
doesn't do a linear search for the corresponding thread_info object.
to PTRACE_TYPE_ARG3.
* linux-low.c: Rename all occurrences of PTRACE_ARG3_TYPE
to PTRACE_TYPE_ARG3 and PTRACE_ARG4_TYPE to
PTRACE_TYPE_ARG4.
* linux-low.h (PTRACE_ARG3_TYPE): Rename to PTRACE_TYPE_ARG3.
(PTRACE_ARG4_TYPE): Rename to PTRACE_TYPE_ARG4.
There's no need for every arch to pre-allocate disabled_regsets.
Chances are the array won't be used.
(I have a hunch that with some more work we could dispense with
initialize_regsets_info.)
Tested on x86_64 Fedora 17 w/ -lmcheck.
gdb/gdbserver/
2013-06-11 Pedro Alves <palves@redhat.com>
* linux-low.c (regset_disabled, disable_regset): New functions.
(regsets_fetch_inferior_registers)
(regsets_store_inferior_registers): Use them.
(initialize_regsets_info); Don't allocate the disabled_regsets
array here.
* linux-low.h (struct regsets_info) <disabled_regsets>: Extend
comment.
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.
This patch adds support for range stepping to GDBserver, teaching it
about vCont;r.
It'd be easy to enable this for all hardware single-step targets
without needing the linux_target_ops hook, however, at least PPC needs
special care, due to the fact that PPC atomic sequences can't be
hardware single-stepped through, a thing which GDBserver doesn't know
about. So this leaves the support limited to x86/x86_64.
gdb/
2013-05-23 Pedro Alves <palves@redhat.com>
* NEWS: Mention GDBserver range stepping support.
gdb/gdbserver/
2013-05-23 Yao Qi <yao@codesourcery.com>
Pedro Alves <palves@redhat.com>
* linux-low.c (lwp_in_step_range): New function.
(linux_wait_1): If the thread was range stepping and stopped
outside the stepping range, report the stop to GDB. Otherwise,
continue stepping. Add range stepping debug output.
(linux_set_resume_request): Copy the step range from the resume
request to the lwp.
(linux_supports_range_stepping): New.
(linux_target_ops) <supports_range_stepping>: Set to
linux_supports_range_stepping.
* linux-low.h (struct linux_target_ops)
<supports_range_stepping>: New field.
(struct lwp_info) <step_range_start, step_range_end>: New fields.
* linux-x86-low.c (x86_supports_range_stepping): New.
(the_low_target) <supports_range_stepping>: Set to
x86_supports_range_stepping.
* server.c (handle_v_cont): Handle 'r' action.
(handle_v_requests): Append ";r" if the target supports range
stepping.
* target.h (struct thread_resume) <step_range_start,
step_range_end>: New fields.
(struct target_ops) <supports_range_stepping>:
New field.
(target_supports_range_stepping): New macro.
A small cleanup. 'struct lwp_info'::thread_known is only useful for
thread-db.c.
gdbserver/
2013-04-16 Pedro Alves <palves@redhat.com>
* linux-low.h (struct lwp_info) <thread_known>: Move under
the USE_THREAD_DB #ifdef.
The previous patches are still not sufficient to build gdbserver with
our copy of thread_db.h.
../../../src/gdb/gdbserver/thread-db.c: In function ‘find_one_thread’:
../../../src/gdb/gdbserver/thread-db.c:316:6: error: ‘struct lwp_info’ has no member named ‘th’
../../../src/gdb/gdbserver/thread-db.c: In function ‘attach_thread’:
../../../src/gdb/gdbserver/thread-db.c:341:6: error: ‘struct lwp_info’ has no member named ‘th’
../../../src/gdb/gdbserver/thread-db.c: In function ‘thread_db_get_tls_address’:
../../../src/gdb/gdbserver/thread-db.c:514:47: error: ‘struct lwp_info’ has no member named ‘th’
make: *** [thread-db.o] Error 1
First, linux-low.h is including <thread_db.h> directly instead of our
gdb_thread_db.h, although thread-db.c includes the latter. Then the
'th' field of struct lwp_info is only defined if HAVE_THREAD_DB_H is
defined, which is not true if we're using our replacement copy of
thread_db.h. We have a USE_THREAD_DB symbol defined if we're building
thread-db.c that's ideal for this, however, it's currently only
defined when compiling linux-low.c (through a Makefile rule). The
patch makes it defined when compiling any file.
gdb/gdbserver/
2013-04-16 Pedro Alves <palves@redhat.com>
* Makefile.in (INTERNAL_CFLAGS): Add @USE_THREAD_DB@.
(linux-low.o): Delete rule.
* linux-low.h: Always include "gdb_thread_db.h" instead of
conditionally including thread_db.h.
(struct lwp_info) <th>: Guard with #ifdef USE_THREAD_DB instead of
HAVE_THREAD_DB_H.
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.
(PTRACE_ARG4_TYPE): Likewise.
(PTRACE_XFER_TYPE): Likewise.
* linux-arm-low.c (arm_prepare_to_resume): Cast third argument of
ptrace to PTRACE_ARG3_TYPE.
* linux-low.c (PTRACE_ARG3_TYPE): Move macro to linux-low.h.
(PTRACE_ARG4_TYPE): Likewise.
(PTRACE_XFER_TYPE): Likewise.
(linux_detach_one_lwp): Cast fourth argument of
ptrace to long then PTRACE_ARG4_TYPE.
(regsets_fetch_inferior_registers): Cast third argument of
ptrace to long then PTRACE_ARG3_TYPE.
(regsets_store_inferior_registers): Likewise.
PR gdb/13969
* linux-low.c (linux_pid_exe_is_elf_64_file): Also return the
e_machine field.
(linux_qxfer_libraries_svr4): Update call to elf_64_file_p.
* linux-low.h (linux_pid_exe_is_elf_64_file): Updated.
* linux-x86-low.c (x86_arch_setup): Check if GDBserver is
compatible with process.
Kwok Cheung Yeung <kcy@codesourcery.com>
* NEWS: Document shorter fast tracepoints and qTMinFTPILen packet.
* i386-tdep.c (i386_fast_tracepoint_valid_at): Query target for
the minimum instruction size for fast tracepoints.
* target.h (struct target_ops): Add new method
to_get_min_fast_tracepoint_insn_len.
(target_get_min_fast_tracepoint_insn_len): New.
* target.c (update_current_target): Set up new target operation.
* remote.c (remote_write_bytes_aux): Fix typo.
(remote_get_min_fast_tracepoint_insn_len): New.
(init_remote_ops): Initialize new field.
* gdb.texinfo (Create and Delete Tracepoints): Describe what is
needed to get shorter fast tracepoints.
(Tracepoint Packets): Document new qTMinFTPILen packet.
* linux-x86-low.c (small_jump_insn): New.
(i386_install_fast_tracepoint_jump_pad): Add arguments for
trampoline and error message, build a trampoline and issue a small
jump instruction to it.
(x86_install_fast_tracepoint_jump_pad): Add arguments for
trampoline and error message.
(x86_get_min_fast_tracepoint_insn_len): New.
(the_low_target): Add call to x86_get_min_fast_tracepoint_insn_len.
* linux-low.h (struct linux_target_ops): Add arguments to
install_fast_tracepoint_jump_pad operation, add new operation.
* linux-low.c (linux_install_fast_tracepoint_jump_pad): Add
arguments.
(linux_get_min_fast_tracepoint_insn_len): New function.
(linux_target_op): Add new operation.
* tracepoint.c (gdb_trampoline_buffer): New IPA variable.
(gdb_trampoline_buffer_end): Ditto.
(gdb_trampoline_buffer_error): Ditto.
(struct ipa_sym_addresses): Add fields for new IPA variables.
(symbol_list): Add entries for new IPA variables.
(struct tracepoint): Add fields to hold the address range of the
trampoline used by the tracepoint.
(trampoline_buffer_head): New static variable.
(trampoline_buffer_tail): Ditto.
(claim_trampoline_space): New function.
(have_fast_tracepoint_trampoline_buffer): New function.
(clone_fast_tracepoint): Fill in trampoline fields of tracepoint
structure.
(install_fast_tracepoint): Ditto, also add error buffer argument.
(cmd_qtminftpilen): New function.
(handle_tracepoint_query): Add response to qTMinFTPILen packet.
(fast_tracepoint_from_trampoline_address): New function.
(fast_tracepoint_collecting): Handle trampoline as part of jump
pad space.
(set_trampoline_buffer_space): New function.
(initialize_tracepoint): Initialize new IPA variables.
* target.h (struct target_ops): Add arguments to
install_fast_tracepoint_jump_pad operation, add new
get_min_fast_tracepoint_insn_len operation.
(target_get_min_fast_tracepoint_insn_len): New.
(install_fast_tracepoint_jump_pad): Add arguments.
* server.h (IPA_BUFSIZ): Define.
* linux-i386-ipa.c: Include extra header files.
(initialize_fast_tracepoint_trampoline_buffer): New function.
(initialize_low_tracepoint): Call it.
* server.h (set_trampoline_buffer_space): Declare.
(claim_trampoline_space): Ditto.
(have_fast_tracepoint_trampoline_buffer): Ditto.
* gdb.trace/ftrace.c: New.
* gdb.trace/ftrace.exp: New.
* linux-x86-low.c (update_debug_registers_callback): New.
(i386_dr_low_set_addr): Use it.
(i386_dr_low_get_addr): New.
(i386_dr_low_set_control): Use update_debug_registers_callback.
(i386_dr_low_get_control): New.
(i386_dr_low_get_status): Adjust.
* linux-low.c (linux_stop_lwp): New.
* linux-low.h (linux_stop_lwp): Declare.
* i386-low.c (I386_DR_GET_RW_LEN): Take the dr7 contents as
argument instead of a i386_debug_reg_state.
(I386_DR_WATCH_HIT): Take the dr6 contents as argument instead of
a i386_debug_reg_state.
(i386_insert_aligned_watchpoint): Adjust.
(i386_remove_aligned_watchpoint): Adjust.
(i386_low_stopped_data_address): Read the debug registers from the
inferior instead of from the mirrors.
* i386-low.h (struct i386_debug_reg_state): Extend comment.
(i386_dr_low_get_addr): Declare.
(i386_dr_low_get_control): Declare.
(i386_dr_low_get_status): Change prototype.
* win32-i386-low.c (dr_status_mirror, dr_control_mirror): New globals.
(i386_dr_low_get_addr): New.
(i386_dr_low_get_control): New.
(i386_dr_low_get_status): Adjust prototype. Return
dr_status_mirror.
(i386_initial_stuff): Clear dr_status_mirror and
dr_control_mirror.
(i386_get_thread_context): Adjust.
(i386_set_thread_context): Adjust.
(i386_thread_added): Adjust.
* proc-service.c (ps_pglobal_lookup): Use
thread_db_look_up_one_symbol.
* remote-utils.c (look_up_one_symbol): Add new `may_ask_gdb'
parameter. Use it instead of all_symbols_looked_up.
* server.h (struct process_info) <all_symbols_looked_up>: Delete
field.
(all_symbols_looked_up): Don't declare.
(look_up_one_symbol): Add new `may_ask_gdb' parameter.
* thread-db.c (struct thread_db) <all_symbols_looked_up>: New
field.
(thread_db_look_up_symbols): Adjust call to look_up_one_symbol.
Set all_symbols_looked_up here.
(thread_db_look_up_one_symbol): New.
(thread_db_get_tls_address): Adjust.
(thread_db_load_search, try_thread_db_load_1): Always allocate the
thread_db object on the heap, and tentatively set it in the
process structure.
(thread_db_init): Don't set all_symbols_looked_up here.
* linux-low.h (thread_db_look_up_one_symbol): Declare.
* linux-low.c (linux_remove_process): Delete.
(add_lwp): Don't set last_resume_kind here.
(linux_kill): Use `mourn'.
(linux_detach): Use `thread_db_detach', and `mourn'.
(linux_mourn): New.
(linux_attach_lwp_1): Adjust comment.
(linux_attach): last_resume_kind moved the thread_info; adjust.
(status_pending_p_callback): Adjust.
(linux_wait_for_event_1): Adjust.
(count_events_callback, select_singlestep_lwp_callback)
(select_event_lwp_callback, cancel_breakpoints_callback)
(db_wants_lwp_stopped, linux_wait_1, need_step_over_p)
(proceed_one_lwp): Adjust.
(linux_async): Add debug output.
(linux_thread_stopped): New.
(linux_pause_all): New.
(linux_target_ops): Install linux_mourn, linux_thread_stopped and
linux_pause_all.
* linux-low.h (struct lwp_info): Delete last_resume_kind field.
(thread_db_free): Delete declaration.
(thread_db_detach, thread_db_mourn): Declare.
* thread-db.c (thread_db_init): Use thread_db_mourn.
(thread_db_free): Delete, split in two.
(disable_thread_event_reporting): New.
(thread_db_detach): New.
(thread_db_mourn): New.
* server.h (struct thread_info) <last_resume_kind>: New field.
<attached>: Add comment.
<gdb_detached>: New field.
(handler_func): Change return type to int.
(handle_serial_event, handle_target_event): Ditto.
(gdb_connected): Declare.
(tracing): Delete.
(disconnected_tracing): Declare.
(stop_tracing): Declare.
* server.c (handle_query) <qSupported>: Report support for
disconnected tracing.
(queue_stop_reply_callback): Account for running threads.
(gdb_wants_thread_stopped): New.
(gdb_wants_all_threads_stopped): New.
(gdb_reattached_process): New.
(handle_status): Clear the `gdb_detached' flag of all processes.
In all-stop, stop all threads.
(main): Be sure to leave tfind mode. Handle disconnected tracing.
(process_serial_event): If the remote connection breaks, or if an
exit was forced with "monitor exit", force an event loop exit.
Handle disconnected tracing on detach.
(handle_serial_event): Adjust.
(handle_target_event): If GDB isn't connected, forward events back
to the inferior, unless the last process exited, in which case,
exit gdbserver. Adjust interface.
* remote-utils.c (remote_open): Don't block in accept. Instead
register an event loop source on the listen socket file
descriptor. Refactor bits into ...
(listen_desc): ... this new global.
(gdb_connected): ... this new function.
(enable_async_notification): ... this new function.
(handle_accept_event): ... this new function.
(remote_close): Clear remote_desc.
* inferiors.c (add_thread): Set the new thread's last_resume_kind.
* target.h (struct target_ops) <mourn, thread_stopped, pause_all>:
New fields.
(mourn_inferior): Define.
(target_process_qsupported): Avoid the dangling else problem.
(thread_stopped): Define.
(pause_all): Define.
(target_waitstatus_to_string): Declare.
* target.c (target_waitstatus_to_string): New.
* tracepoint.c (tracing): Make extern.
(disconnected_tracing): New.
(stop_tracing): Make extern. Handle tracing stops due to GDB
disconnecting.
(cmd_qtdisconnected): New.
(cmd_qtstatus): Report disconnected tracing status in trace reply.
(handle_tracepoint_general_set): Handle QTDisconnected.
* event-loop.c (event_handler_func): Change return type to int.
(process_event): Bail out if the event handler wants the event
loop to stop.
(handle_file_event): Ditto.
(start_event_loop): Bail out if the event handler wants the event
loop to stop.
* nto-low.c (nto_target_ops): Adjust.
* spu-low.c (spu_wait): Don't remove the process here.
(spu_target_ops): Adjust.
* win32-low.c (win32_wait): Don't remove the process here.
(win32_target_ops): Adjust.
`stopped_by_watchpoint' and `stopped_data_address'.
* linux-low.c (linux_wait_for_lwp): Check for watchpoint triggers
here, and cache them in the lwp object.
(wait_for_sigstop): Check stopped_by_watchpoint lwp field
directly.
(linux_resume_one_lwp): Clear the lwp's stopped_by_watchpoint
field.
(linux_stopped_by_watchpoint): Rewrite.
(linux_stopped_data_address): Rewrite.
Pass it to thread_db_free.
(linux_kill, linux_detach, linux_wait_1): Adjust to pass the
proper `detaching' argument to linux_remove_process.
* linux-low.h (thread_db_free): Add `detaching' parameter.
* thread-db.c (thread_db_init): Pass false as `detaching' argument
to thread_db_free.
(thread_db_free): Add `detaching' parameter. Only
call td_ta_clear_event if detaching from process.
Don Breazeal