This change is relevant only for standard DWARF (as opposed to the GNAT
encodings extensions): at the time of writing it only makes a difference
with GCC patches that are to be integrated: see the patch series
submission at
<https://gcc.gnu.org/ml/gcc-patches/2015-07/msg01353.html>.
Given the following Ada declarations:
subtype Small_Int is Natural range 0 .. 100;
type R_Type (L : Small_Int := 0) is record
S : String (1 .. L);
end record;
type A_Type is array (Natural range <>) of R_Type;
A : A_Type := (1 => (L => 0, S => ""),
2 => (L => 2, S => "ab"));
Before this change, we would get the following GDB session:
(gdb) ptype a
type = array (1 .. 2) of foo.r_type <packed: 838-bit elements>
This is wrong: "a" is not a packed array. This output comes from the
fact that, because R_Type has a dynamic size (with a maximum), the
compiler has to describe in the debugging information the size allocated
for each array element (i.e. the stride, in DWARF parlance: see
DW_AT_byte_stride). Ada type printing currently assumes that arrays
with a stride are packed, hence the above output.
In practice, GNAT never performs bit-packing for arrays that contain
variable-sized elements. Leveraging this fact, this patch enhances type
printing so that ptype does not pretend that arrays are packed when they
have a stride and they contain dynamic elements. After this change, we
get the following expected output:
(gdb) ptype a
type = array (1 .. 2) of foo.r_type
gdb/ChangeLog:
* ada-typeprint.c (print_array_type): Do not describe arrays as
packed when they embed dynamic elements.
gdb/testsuite/ChangeLog:
* gdb.ada/array_of_variable_length.exp: New testcase.
* gdb.ada/array_of_variable_length/foo.adb: New file.
* gdb.ada/array_of_variable_length/pck.adb: New file.
* gdb.ada/array_of_variable_length/pck.ads: New file.
Tested on x86_64-linux, no regression.
clang names the local variable t_structs_a.buf.
gdb/testsuite/ChangeLog:
* gdb.base/callfuncs.exp (do_function_calls): Handle clang naming
of function static local variable.
2015-09-15 Max Filippov <jcmvbkbc@gmail.com>
bfd/
* elf32-xtensa.c (elf_xtensa_be_plt_entry)
(elf_xtensa_le_plt_entry): Emit 'entry' instruction only for
windowed ABI.
(elf_xtensa_create_plt_entry): Generate 'l32r' offsets and fix
up instructions according to ABI.
The previous manual change was wrong. The vfork parent thread ID
should be reported with the usual "thread" magic register:
Sending packet: $vCont;c:p7260.7260#1e...Packet received: OK
- Notification received: Stop:T05vforkdone:;
+ Notification received: Stop:T05vforkdone:;thread:p7260.7260
^^^^^^^^^^^^^^^^^
This is already how the parent is reported in the vfork/fork events,
and is actually what the fix made gdbserver do. Following the
documentation change, the event would have been reported like this
instead:
Notification received: Stop:T05vforkdone:p7260.7260
gdb/doc/ChangeLog:
2015-09-15 Pedro Alves <palves@redhat.com>
PR remote/18965
* gdb.texinfo (Stop Reply Packets): Revert previous change to
the vforkdone description.
ppc64le loses control when stepping between two PLT-called functions inside
a shared library:
29 shlib_second (); /* first-hit */^M
(gdb) PASS: gdb.base/solib-intra-step.exp: first-hit
step^M
^M
Program received signal SIGABRT, Aborted.^M
0x00003fffb7cbe578 in __GI_raise (sig=<optimized out>) at ../nptl/sysdeps/unix/sysv/linux/raise.c:56^M
56 return INLINE_SYSCALL (tgkill, 3, pid, selftid, sig);^M
(gdb) FAIL: gdb.base/solib-intra-step.exp: second-hit
->
29 shlib_second (); /* first-hit */^M
(gdb) PASS: gdb.base/solib-intra-step.exp: first-hit
step^M
shlib_second () at ./gdb.base/solib-intra-step-lib.c:23^M
23 abort (); /* second-hit */^M
(gdb) PASS: gdb.base/solib-intra-step.exp: second-hit
This is because gdbarch_skip_trampoline_code() will resolve the final function
as shlib_second+0 and place there the breakpoint, but ld.so will jump after
the breakpoint - at shlib_second+8 - as it is ELFv2 local symbol optimization:
Dump of assembler code for function shlib_second:
0x0000000000000804 <+0>: addis r2,r12,2
0x0000000000000808 <+4>: addi r2,r2,30668
0x000000000000080c <+8>: mflr r0
Currently gdbarch_skip_entrypoint() has been called in skip_prologue_sal() and
fill_in_stop_func() but that is not enough. I believe
gdbarch_skip_entrypoint() should be called after every
gdbarch_skip_trampoline_code().
gdb/ChangeLog
2015-09-15 Jan Kratochvil <jan.kratochvil@redhat.com>
* linespec.c (minsym_found): Call gdbarch_skip_entrypoint.
* ppc64-tdep.c (ppc64_skip_trampoline_code): Rename to ...
(ppc64_skip_trampoline_code_1): ... here.
(ppc64_skip_trampoline_code): New wrapper function.
* symtab.c (find_function_start_sal): Call gdbarch_skip_entrypoint.
gdb/testsuite/ChangeLog
2015-09-15 Jan Kratochvil <jan.kratochvil@redhat.com>
* gdb.opt/solib-intra-step-lib.c: New file.
* gdb.opt/solib-intra-step-main.c: New file.
* gdb.opt/solib-intra-step.exp: New file.
gdb/ChangeLog -> gdb/gdbserver/ChangeLog
2015-09-15 Pedro Alves <palves@redhat.com>
PR remote/18965
* remote-utils.c (prepare_resume_reply): Merge
TARGET_WAITKIND_VFORK_DONE switch case with the
TARGET_WAITKIND_FORKED case.
The vforkdone stop reply misses indicating the thread ID of the vfork
parent which the event relates to:
@cindex vfork events, remote reply
@item vfork
The packet indicates that @code{vfork} was called, and @var{r}
is the thread ID of the new child process. Refer to
@ref{thread-id syntax} for the format of the @var{thread-id}
field. This packet is only applicable to targets that support
vfork events.
@cindex vforkdone events, remote reply
@item vforkdone
The packet indicates that a child process created by a vfork
has either called @code{exec} or terminated, so that the
address spaces of the parent and child process are no longer
shared. The @var{r} part is ignored. This packet is only
applicable to targets that support vforkdone events.
Unfortunately, this is not just a documentation issue. GDBserver
is really not specifying the thread ID. I noticed because
in non-stop mode, gdb complains:
[Thread 6089.6089] #1 stopped.
#0 0x0000003615a011f0 in ?? ()
0x0000003615a011f0 in ?? ()
(gdb) set debug remote 1
(gdb) c
Continuing.
Sending packet: $QPassSignals:e;10;14;17;1a;1b;1c;21;24;25;2c;4c;#5f...Packet received: OK
Sending packet: $vCont;c:p17c9.17c9#88...Packet received: OK
Notification received: Stop:T05vfork:p17ce.17ce;06:40d7ffffff7f0000;07:30d7ffffff7f0000;10:e4c9eb1536000000;thread:p17c9.17c9;core:2;
Sending packet: $vStopped#55...Packet received: OK
Sending packet: $D;17ce#af...Packet received: OK
Sending packet: $vCont;c:p17c9.17c9#88...Packet received: OK
Notification received: Stop:T05vforkdone:;
No process or thread specified in stop reply: T05vforkdone:;
(gdb)
This is not non-stop-mode-specific, however. Consider e.g., that in
all-stop, you may be debugging more than one process at the same time.
You continue, and both processes vfork. So when you next get a
T05vforkdone, there's no way to tell which of the parent processes is
done with the vfork.
Tests will be added later.
Tested on x86_64 Fedora 20.
gdb/ChangeLog:
2015-09-15 Pedro Alves <palves@redhat.com>
PR remote/18965
* remote-utils.c (prepare_resume_reply): Merge
TARGET_WAITKIND_VFORK_DONE switch case with the
TARGET_WAITKIND_FORKED case.
gdb/doc/ChangeLog:
2015-09-15 Pedro Alves <palves@redhat.com>
PR remote/18965
* gdb.texinfo (Stop Reply Packets): Explain that vforkdone's 'r'
part indicates the thread ID of the parent process.
gdb.threads/non-ldr-exc-3.exp is sometimes failing like this:
[Switching to Thread 6831.6832]
Breakpoint 2, thread_execler (arg=0x0) at /home/pedro/gdb/mygit/build/../src/gdb/testsuite/gdb.threads/non-ldr-exc-3.c:41
41 if (execl (image, image, argv1, NULL) == -1) /* break-here */
PASS: gdb.threads/non-ldr-exc-3.exp: lock-sched=on,non-stop=off: continue to breakpoint
(gdb) set scheduler-locking on
(gdb) FAIL: gdb.threads/non-ldr-exc-3.exp: lock-sched=on,non-stop=off: set scheduler-locking on
The problem is that the gdb_test_multiple is missing the prompt
anchor. The problem was introduced by 2fd33e9448. This reverts the
hunk that introduced the problem, reverting back to
gdb_continue_to_breakpoint.
gdb/testsuite/ChangeLog:
2015-09-15 Pedro Alves <palves@redhat.com>
* gdb.threads/non-ldr-exc-3.exp (do_test): Use
gdb_continue_to_breakpoint instead of gdb_test_multiple.
Nowadays, GDB only knows whether architecture supports hardware single
step or software single step (through gdbarch hook software_single_step),
and for a given instruction or instruction sequence, GDB knows how to
do single step (hardware or software). However, GDB doesn't know whether
the target supports hardware single step. It is possible that the
architecture doesn't support hardware single step, such as arm, but
the target supports, such as simulator. This was discussed in this
thread https://www.sourceware.org/ml/gdb/2009-12/msg00033.html before.
I encounter this problem for aarch64 multi-arch support. When aarch64
debugs arm program, gdbarch is arm, so software single step is still
used. However, the underneath linux kernel does support hardware
single step, so IWBN to use it.
This patch is to add a new target_ops hook to_can_do_single_step, and
only use it in arm_linux_software_single_step to decide whether or not
to use hardware single step. On the native aarch64 linux target, 1 is
returned. On other targets, -1 is returned. On the remote target, if
the target supports s and S actions in the vCont? reply, then target
can do single step. However, old GDBserver will send s and S in the
reply to vCont?, which will confuse new GDB. For example, old GDBserver
on arm-linux will send s and S in the reply to vCont?, but it doesn't
support hardware single step. On the other hand, new GDBserver, on
arm-linux for example, will not send s and S in the reply to vCont?,
but old GDB thinks it doesn't support vCont packet at all. In order
to address this problem, I add a new qSupported feature vContSupported,
which indicates GDB wants to know the supported actions in the reply
to vCont?, and qSupported response contains vContSupported if the
stub is able tell supported vCont actions in the reply of vCont?.
If the patched GDB talks with patched GDBserver on x86, the RSP traffic
is like this:
-> $qSupported:...+;vContSupported+
<- ...+;vContSupported+
...
-> $vCont?
<- vCont;c;C;t;s;S;r
then, GDB knows the stub can do single step, and may stop using software
single step even the architecture doesn't support hardware single step.
If the patched GDB talks with patched GDBserver on arm, the last vCont?
reply will become:
<- vCont;c;C;t
GDB thinks the target doesn't support single step, so it will use software
single step.
If the patched GDB talks with unpatched GDBserver, the RSP traffic is like
this:
-> $qSupported:...+;vContSupported+
<- ...+
...
-> $vCont?
<- vCont;c;C;t;s;S;r
although GDBserver returns s and S, GDB still thinks GDBserver may not
support single step because it doesn't support vContSupported.
If the unpatched GDB talks with patched GDBserver on x86, the RSP traffic
is like:
-> $qSupported:...+;
<- ...+;vContSupported+
...
-> $vCont?
<- vCont;c;C;t;s;S;r
Since GDB doesn't sent vContSupported in the qSupported feature, GDBserver
sends s and S regardless of the support of hardware single step.
gdb:
2015-09-15 Yao Qi <yao.qi@linaro.org>
* aarch64-linux-nat.c (aarch64_linux_can_do_single_step): New
function.
(_initialize_aarch64_linux_nat): Install it to to_can_do_single_step.
* arm-linux-tdep.c (arm_linux_software_single_step): Return 0
if target_can_do_single_step returns 1.
* remote.c (struct vCont_action_support) <s, S>: New fields.
(PACKET_vContSupported): New enum.
(remote_protocol_features): New element for vContSupported.
(remote_query_supported): Append "vContSupported+".
(remote_vcont_probe): Remove support_s and support_S, use
rs->supports_vCont.s and rs->supports_vCont.S instead. Disable
vCont packet if c and C actions are not supported.
(remote_can_do_single_step): New function.
(init_remote_ops): Install it to to_can_do_single_step.
(_initialize_remote): Call add_packet_config_cmd.
* target.h (struct target_ops) <to_can_do_single_step>: New field.
(target_can_do_single_step): New macro.
* target-delegates.c: Re-generated.
gdb/gdbserver:
2015-09-15 Yao Qi <yao.qi@linaro.org>
* server.c (vCont_supported): New global variable.
(handle_query): Set vCont_supported to 1 if "vContSupported+"
matches. Append ";vContSupported+" to own_buf.
(handle_v_requests): Append ";s;S" to own_buf if target supports
hardware single step or vCont_supported is false.
(capture_main): Set vCont_supported to zero.
gdb/doc:
2015-09-15 Yao Qi <yao.qi@linaro.org>
* gdb.texinfo (General Query Packets): Add vContSupported to
tables of 'gdbfeatures' and 'stub features' supported in the
qSupported packet, as well as to the list containing stub
feature details.
In my patch https://sourceware.org/ml/gdb-patches/2015-04/msg01110.html
a new target_ops hook supports_conditional_breakpoints was added to
disable conditional breakpoints if target doesn't have hardware single
step. This patch is to generalize this hook from
supports_conditional_breakpoints to supports_hardware_single_step,
so that the following patch can use it.
gdb/gdbserver:
2015-09-15 Yao Qi <yao.qi@linaro.org>
* linux-low.c (linux_supports_conditional_breakpoints): Rename
it to ...
(linux_supports_hardware_single_step): ... New function.
(linux_target_ops): Update.
* lynx-low.c (lynx_target_ops): Set field
supports_hardware_single_step to target_can_do_hardware_single_step.
* nto-low.c (nto_target_ops): Likewise.
* spu-low.c (spu_target_ops): Likewise.
* win32-low.c (win32_target_ops): Likewise.
* target.c (target_can_do_hardware_single_step): New function.
* target.h (struct target_ops) <supports_conditional_breakpoints>:
Remove. <supports_hardware_single_step>: New field.
(target_supports_conditional_breakpoints): Remove.
(target_supports_hardware_single_step): New macro.
(target_can_do_hardware_single_step): Declare.
* server.c (handle_query): Use target_supports_hardware_single_step
instead of target_supports_conditional_breakpoints.
This patch is to fixup the siginfo_t when aarch64 gdb or gdbserver
read from or write to the arm inferior. It is to convert the
"struct siginfo_t" between aarch64 and arm, which is quite mechanical.
gdb/gdbserver:
2015-09-15 Yao Qi <yao.qi@linaro.org>
* linux-aarch64-low.c (aarch64_linux_siginfo_fixup): New
function.
(struct linux_target_ops the_low_target): Install
aarch64_linux_siginfo_fixup.
gdb:
2015-09-15 Yao Qi <yao.qi@linaro.org>
* aarch64-linux-nat.c (aarch64_linux_siginfo_fixup): New function.
(_initialize_aarch64_linux_nat): Call linux_nat_set_siginfo_fixup.
* nat/aarch64-linux.c (aarch64_compat_siginfo_from_siginfo):
New function.
(aarch64_siginfo_from_compat_siginfo): New function.
* nat/aarch64-linux.h: Include signal.h.
(compat_int_t, compat_uptr_t, compat_time_t): Typedef.
(compat_timer_t, compat_clock_t): Likewise.
(struct compat_timeval): New.
(union compat_sigval): New.
(struct compat_siginfo): New.
(cpt_si_pid, cpt_si_uid, cpt_si_timerid): New macros.
(cpt_si_overrun, cpt_si_status, cpt_si_utime): Likewise.
(cpt_si_stime, cpt_si_ptr, cpt_si_addr): Likewise.
(cpt_si_band, cpt_si_fd): Likewise.
Fix it so that it's compatible with the kernel and other FDPIC targets.
* elf32-sh.c (sh_elf_relocate_section): Set EF_SH_PIC flag
instead of clearing it on cross-section relocations.
(sh_elf_merge_private_data): Clear EF_SH_PIC flag by default.
This patch, relative to a tree with
https://sourceware.org/ml/gdb-patches/2015-08/msg00295.html, fixes
issues/crashes that trigger if something unexpected happens during a
hook-stop.
E.g., if the inferior disappears while running the hook-stop, we hit
failed assertions:
(gdb) define hook-stop
Type commands for definition of "hook-stop".
End with a line saying just "end".
>kill
>end
(gdb) si
Kill the program being debugged? (y or n) [answered Y; input not from terminal]
/home/pedro/gdb/mygit/build/../src/gdb/thread.c:88: internal-error: inferior_thread: Assertion `tp' failed.
A problem internal to GDB has been detected,
further debugging may prove unreliable.
Quit this debugging session? (y or n)
I noticed that if a hook-stop issues a synchronous execution command,
we print the same stop event twice:
(gdb) define hook-stop
Type commands for definition of "hook-stop".
End with a line saying just "end".
>si
>end
(gdb) si
0x000000000040074a 42 args[i] = 1; /* Init value. */ <<<<<<< once
0x000000000040074a 42 args[i] = 1; /* Init value. */ <<<<<<< twice
(gdb)
In MI:
*stopped,reason="end-stepping-range",frame={addr="0x000000000040074a",func="main",args=[],file="threads.c",fullname="/home/pedro/gdb/tests/threads.c",line="42"},thread-id="1",stopped-threads="all",core="0"
*stopped,reason="end-stepping-range",frame={addr="0x000000000040074a",func="main",args=[],file="threads.c",fullname="/home/pedro/gdb/tests/threads.c",line="42"},thread-id="1",stopped-threads="all",core="0"
(gdb)
The fix has GDB stop processing the event if the context changed. I
don't expect people to be doing crazy things from the hook-stop.
E.g., it gives me headaches to try to come up a proper behavior for
handling a thread change from a hook-stop... (E.g., imagine the
hook-stop does thread N; step, with scheduler-locing on). I think the
most important bit here is preventing crashes.
The patch adds a new hook-stop.exp test that covers the above and also
merges in the old hook-stop-continue.exp and hook-stop-frame.exp into
the same framework.
gdb/ChangeLog:
2015-09-14 Pedro Alves <palves@redhat.com>
* infrun.c (current_stop_id): New global.
(get_stop_id, new_stop_id): New functions.
(fetch_inferior_event): Handle normal_stop proceeding the target.
(struct stop_context): New.
(save_stop_context, release_stop_context_cleanup)
(stop_context_changed): New functions.
(normal_stop): Return true if the hook-stop changes the stop
context.
* infrun.h (get_stop_id): Declare.
(normal_stop): Now returns int. Add documentation.
gdb/testsuite/ChangeLog:
2015-09-14 Pedro Alves <palves@redhat.com>
* gdb.base/hook-stop-continue.c: Delete.
* gdb.base/hook-stop-continue.exp: Delete.
* gdb.base/hook-stop-frame.c: Delete.
* gdb.base/hook-stop-frame.exp: Delete.
* gdb.base/hook-stop.c: New file.
* gdb.base/hook-stop.exp: New file.
This change is relevant only for standard DWARF (as opposed to the GNAT
encodings extensions): at the time of writing it only makes a difference
with GCC patches that are to be integrated: see in particular
<https://gcc.gnu.org/ml/gcc-patches/2015-07/msg01364.html>.
Given the following Ada declarations:
type Small is mod 2 ** 6;
type Array_Type is array (0 .. 9) of Small
with Pack;
type Array_Access is access all Array_Type;
A : aliased Array_Type := (1, 2, 3, 4, 5, 6, 7, 8, 9, 10);
AA : constant Array_Type := A'Access;
Before this change, we would get the following GDB session:
(gdb) print aa.all(2)
$1 = 3
(gdb) print aa(2)
$2 = 16
This is wrong: both expression should yield the same value: 3. The
problem is simply that the routine which handles accesses to arrays lack
general handling for packed arrays. After this patch, we have the
expected output:
(gdb) print aa.all(2)
$1 = 3
(gdb) print aa(2)
$2 = 3
gdb/ChangeLog:
* ada-lang.c (ada_value_ptr_subscript): Update the heading
comment. Handle packed arrays.
gdb/testsuite/ChangeLog:
* gdb.ada/access_to_packed_array.exp: New testcase.
* gdb.ada/access_to_packed_array/foo.adb: New file.
* gdb.ada/access_to_packed_array/pack.adb: New file.
* gdb.ada/access_to_packed_array/pack.ads: New file.
Tested on x86_64-linux, no regression.
Commit fbea99ea8a added this to both the "Changes in GDB 7.10" and
"Changes since GDB 7.10" sections by mistake.
gdb/ChangeLog:
2015-09-14 Pedro Alves <palves@redhat.com>
* NEWS (Changes in GDB 7.10, New commands>: Remove duplicate
mention of maint set/show target-non-stop.
The gdb.btrace/buffer-size.exp test starts recording with an unlimited
buffer size. This will, for a short time, use up most if not all BTS
resources.
I don' think this test is necessary. Remove it.
testsuite/
* gdb.btrace/buffer-size.exp: Remove recording with unlimited BTS
buffer size test.
This patch adds documentation of support for exec events on
extended-remote Linux targets.
gdb/ChangeLog:
* NEWS: Announce new remote packets for the exec-events
feature and the exec-events feature and associated commands.
gdb/doc/ChangeLog:
* gdb.texinfo (Remote Configuration): Add exec event
feature to table of packet settings.
(Stop Reply Packets): Add exec events to the list of stop
reasons.
(General Query Packets): Add exec events to tables of
'gdbfeatures' and 'stub features' supported in the qSupported
packet, as well as to the list containing stub feature
details.
This patch updates several exec-related tests and some of the library
functions in order to get them running with extended-remote. There were
three changes that were required, as follows:
In gdb.base/foll-exec.exp, use 'clean_start' in place of proc 'zap_session'
to reset the state of the debugger between tests. This sets 'remote
exec-file' to execute the correct binary file in each subsequent test.
In gdb.base/pie-execl.exp, there is an expect statement with an expression
that is used to match output from both gdb and the program under debug.
For the remote target, this had to be split into two expressions, using
$inferior_spawn_id to match the output from the program.
Because I had encountered problems with extended-remote exec events in
non-stop mode in my manual testing, I added non-stop testing to the
non-ldr-exc-[1234].exp tests. In order to set non-stop mode for remote
targets, it is necessary to 'set non-stop on' after gdb has started, but
before it connects to gdbserver. This is done using 'save_vars' to set
non-stop mode in GDBFLAGS, so GDB sets non-stop mode on startup.
gdb/testsuite/ChangeLog:
* gdb.base/foll-exec.c: Add copyright header. Fix
formatting issues.
* gdb.base/foll-exec.exp (zap_session): Delete proc.
(do_exec_tests): Use clean_restart in place of zap_session,
and for test initialization. Fix formatting issues. Use
fail in place of perror.
* gdb.base/pie-execl.exp (main): Use 'inferior_spawn_id' in
an expect statement to match an expression with output from
the program under debug.
* gdb.threads/non-ldr-exc-1.exp (do_test, main): Add
non-stop tests and pass stop mode argument to clean_restart.
Use save_vars to enable non-stop in GDBFLAGS.
* gdb.threads/non-ldr-exc-2.exp: Likewise.
* gdb.threads/non-ldr-exc-3.exp: Likewise.
* gdb.threads/non-ldr-exc-4.exp: Likewise.
This patch implements exec catchpoints for extended-remote Linux
targets. The implementation follows the same approach used for
fork catchpoints, implementing extended-remote target routines for
inserting and removing the catchpoints by just checking if exec events
are supported. Existing host-side code and previous support for
extended-remote exec events takes care of the rest.
gdb/ChangeLog:
* remote.c (remote_exec_event_p): New function.
(remote_insert_exec_catchpoint): New function.
(remote_remove_exec_catchpoint): New function.
(init_extended_remote_ops): Initialize extended_remote_ops
members to_insert_exec_catchpoint and
to_remove_exec_catchpoint.
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.
Weak defined function is turned into non-weak defined function by
"ld -r -flto" with GCC 5 due to a GCC 5 regression:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67548
Add "ld -r" tests for PR ld/15323 to make sure that any linker change
won't introduce linker regression for PR ld/15323.
* ld-plugin/lto.exp (lto_link_tests): Add a "ld -r" test for
PR ld/15323.
(lto_run_tests): Add a "ld -r" test for PR ld/15323.
gdb/ChangeLog:
* aarch64-tdep.c (decode_cb): Move up comment describing the
encoding.
(decode_tb): Fix a typo in comment above the function. Move up
comment describing the encoding.
The encoding of the b.cond instruction is described in the architecture
reference manual as:
b.cond 0101 0100 iiii iiii iiii iiii iii0 cccc
So the mask should be 0xff000010.
gdb/ChangeLog:
* aarch64-tdep.c (decode_bcond): Fix incorrect mask.
I found this const/not const mixup found by building in C++ mode.
gdb/ChangeLog:
* ada-lang.c (ada_search_struct_field): Constify parameters
and/or variables..
(xget_renaming_scope): Likewise.
(ada_is_redundant_range_encoding): Likewise.
(scan_discrim_bound): Likewise.
(to_fixed_range_type): Likewise.
This fixes the instruction format for 3 of the compare and branch
extended mnemonics. That way the extended mnemonics are actually
being found by objdump.
gas/testsuite/ChangeLog:
2015-09-10 Andreas Krebbel <krebbel@linux.vnet.ibm.com>
* gas/s390/zarch-z10.d: Fix testcase for some of the compare and
branch extended mnemonics.
opcodes/ChangeLog:
2015-09-10 Andreas Krebbel <krebbel@linux.vnet.ibm.com>
* s390-opc.txt: Fix instruction format of crj*, clrj*, and clgrj*.
This is cleanup only.
opcodes/ChangeLog:
2015-09-10 Andreas Krebbel <krebbel@linux.vnet.ibm.com>
* s390-opc.c: Remove unused (and broken) F_20 and FE_20 operand
types and adjust numbering accordingly. Fix some comments.
This makes objdump to be able to recognize some of the extended
mnemonics more often. It does not lead to wrong being generated.
opcodes/ChangeLog:
2015-09-10 Andreas Krebbel <krebbel@linux.vnet.ibm.com>
* s390-opc.c: Fix MASK_RIE_R0PI and MASK_RIE_R0PU.
gas/testsuite/ChangeLog:
2015-09-10 Andreas Krebbel <krebbel@linux.vnet.ibm.com>
* gas/s390/zarch-z10.d: Fix testcase for compare and branch
extended mnemonics.
Nowadays, GDB calls target_can_download_tracepoint at the entry of
download_tracepoint_locations, which is called by.
update_global_location_list. Sometimes, it is not needed to call
target_can_download_tracepoint at all because there is no tracepoint
created. In remote target, target_can_download_tracepoint send
qTStatus to the remote in order to know whether tracepoint can be
downloaded or not. This means some redundant qTStatus packets are
sent.
This patch is to teach GDB to call target_can_download_tracepoint
lazily, only on the moment there are tracepoint to download.
gdb.perf/single-step.exp (with a local patch to measure RSP packets)
shows the number of RSP packets is reduced because there is no
tracepoint at all, so GDB doesn't send qTStatus any more.
# of RSP packets
original patched
single-step rsp 1000 7000 6000
single-step rsp 2000 14000 12000
single-step rsp 3000 21000 18000
single-step rsp 4000 28000 24000
gdb:
2015-09-10 Yao Qi <yao.qi@linaro.org>
* breakpoint.c (download_tracepoint_locations): New local
can_download_tracepoint. Check the result of
target_can_download_tracepoint and save it in
can_download_tracepoint if there are tracepoints to download.
* linux-nat.h (enum tribool): Move it to ...
* common/common-types.h: ... here.
* strings.c: Add -s/--output-separator option to specify custom
separator string.
* NEWS: Mention the new feature.
* doc/binutils.text (strings): Document the new command line
option.
gdb/ChangeLog:
2015-09-09 Pedro Alves <palves@redhat.com>
* breakpoint.c: Include "thread-fsm.h".
(struct until_break_command_continuation_args): Delete.
(struct until_break_fsm): New.
(until_break_fsm_ops): New global.
(new_until_break_fsm, until_break_fsm_should_stop): New functions.
(until_break_command_continuation): Delete.
(until_break_fsm_clean_up): New function.
(until_break_fsm_async_reply_reason): New function.
(until_break_command): Adjust to create an until_break_fsm instead
of a continuation.
(momentary_bkpt_print_it): No longer print MI's async-stop-reason
here.
* infcmd.c (struct until_next_fsm): New.
(until_next_fsm_ops): New global.
(new_until_next_fsm, until_next_fsm_should_stop): New function.
(until_next_continuation): Delete.
(until_next_fsm_clean_up, until_next_fsm_async_reply_reason): New
functions.
(until_next_command): Adjust to create a new until_next_fsm
instead of a continuation.
Pierre-Marie de Rodat
Doug Evans
Max Filippov
Philippe Waroquiers
Pedro Alves
Pierre Langlois
Jan Kratochvil
Yao Qi
GDB Administrator
Rich Felker
Markus Metzger
John David Anglin
Don Breazeal
H.J. Lu
Mihail-Marian Nistor
Simon Marchi
Andreas Krebbel
Nick Clifton
Erik Ackermann