Commit Graph

80 Commits

Author SHA1 Message Date
Ilya Leoshkevich
1ea96f1ded gdbstub: Support disablement in a multi-threaded process
The upcoming follow-fork-mode child support will require disabling
gdbstub in the parent process, which may have multiple threads (which
are represented as CPUs).

Loop over all CPUs in order to remove breakpoints and disable
single-step. Move the respective code into a separate function.

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Message-Id: <20240219141628.246823-2-iii@linux.ibm.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20240305121005.3528075-3-alex.bennee@linaro.org>
2024-03-06 12:35:19 +00:00
Alex Bennée
c3d0b46645 gdbstub: expose api to find registers
Expose an internal API to QEMU to return all the registers for a vCPU.
The list containing the details required to called gdb_read_register().

Based-on:  <20231025093128.33116-15-akihiko.odaki@daynix.com>
Cc: Akihiko Odaki <akihiko.odaki@daynix.com>
Reviewed-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20240227144335.1196131-22-alex.bennee@linaro.org>
2024-02-28 09:11:42 +00:00
Akihiko Odaki
eb37086fb0 gdbstub: Add members to identify registers to GDBFeature
These members will be used to help plugins to identify registers.
The added members in instances of GDBFeature dynamically generated by
CPUs will be filled in later changes.

Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Message-Id: <20231213-gdb-v17-10-777047380591@daynix.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20240227144335.1196131-15-alex.bennee@linaro.org>
2024-02-28 09:10:11 +00:00
Akihiko Odaki
ecd6f6a882 gdbstub: Infer number of core registers from XML
GDBFeature has the num_regs member so use it where applicable to
remove magic numbers.

Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Message-Id: <20231213-gdb-v17-8-777047380591@daynix.com>
[AJB: remove core reg check from microblaze read reg]
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20240227144335.1196131-13-alex.bennee@linaro.org>
2024-02-28 09:09:58 +00:00
Akihiko Odaki
ee59fa1dd5 gdbstub: Simplify XML lookup
Now we know all instances of GDBFeature that is used in CPU so we can
traverse them to find XML. This removes the need for a CPU-specific
lookup function for dynamic XMLs.

Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20231213-gdb-v17-7-777047380591@daynix.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20240227144335.1196131-12-alex.bennee@linaro.org>
2024-02-28 09:09:55 +00:00
Akihiko Odaki
66260159a7 gdbstub: Change gdb_get_reg_cb and gdb_set_reg_cb
Align the parameters of gdb_get_reg_cb and gdb_set_reg_cb with the
gdb_read_register and gdb_write_register members of CPUClass to allow
to unify the logic to access registers of the core and coprocessors
in the future.

Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20231213-gdb-v17-6-777047380591@daynix.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20240227144335.1196131-11-alex.bennee@linaro.org>
2024-02-28 09:09:49 +00:00
Akihiko Odaki
c494f8f529 gdbstub: Use GDBFeature for GDBRegisterState
Simplify GDBRegisterState by replacing num_regs and xml members with
one member that points to GDBFeature.

Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-Id: <20231213-gdb-v17-5-777047380591@daynix.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20240227144335.1196131-10-alex.bennee@linaro.org>
2024-02-28 09:09:43 +00:00
Akihiko Odaki
ac1e867100 gdbstub: Use GDBFeature for gdb_register_coprocessor
This is a tree-wide change to introduce GDBFeature parameter to
gdb_register_coprocessor(). The new parameter just replaces num_regs
and xml parameters for now. GDBFeature will be utilized to simplify XML
lookup in a following change.

Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Acked-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20231213-gdb-v17-4-777047380591@daynix.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20240227144335.1196131-9-alex.bennee@linaro.org>
2024-02-28 09:09:34 +00:00
Ilya Leoshkevich
046f143c51 gdbstub: Implement catching syscalls
GDB supports stopping on syscall entry and exit using the "catch
syscall" command. It relies on 3 packets, which are currently not
supported by QEMU:

* qSupported:QCatchSyscalls+ [1]
* QCatchSyscalls: [2]
* T05syscall_entry: and T05syscall_return: [3]

Implement generation and handling of these packets.

[1] https://sourceware.org/gdb/current/onlinedocs/gdb.html/General-Query-Packets.html#qSupported
[2] https://sourceware.org/gdb/current/onlinedocs/gdb.html/General-Query-Packets.html#QCatchSyscalls
[3] https://sourceware.org/gdb/current/onlinedocs/gdb.html/Stop-Reply-Packets.html

Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Message-Id: <20240202152506.279476-5-iii@linux.ibm.com>
[AJB: GString -> g_strdup_printf]
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20240207163812.3231697-14-alex.bennee@linaro.org>
2024-02-09 17:52:40 +00:00
Ilya Leoshkevich
0a0d87c9b8 gdbstub: Add syscall entry/return hooks
The upcoming syscall catchpoint support needs to get control on syscall
entry and return. Provide the necessary hooks for that, which are
no-ops for now.

Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Message-Id: <20240202152506.279476-4-iii@linux.ibm.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20240207163812.3231697-13-alex.bennee@linaro.org>
2024-02-09 17:52:40 +00:00
Ilya Leoshkevich
8b7fcb8ed1 gdbstub: Allow specifying a reason in stop packets
The upcoming syscall catchpoint support needs to send stop packets with
an associated reason to GDB. Add an extra parameter to gdb_handlesig()
for that, and rename it to gdb_handlesig_reason(). Provide a
compatibility wrapper with an old name.

Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Message-Id: <20240202152506.279476-3-iii@linux.ibm.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20240207163812.3231697-12-alex.bennee@linaro.org>
2024-02-09 17:52:40 +00:00
Ilya Leoshkevich
4aad096587 gdbstub: Expose TARGET_SIGTRAP in a target-agnostic way
The upcoming syscall catchpoint support needs to send SIGTRAP stop
packets to GDB. Being able to compile this support only once for all
targets is a good thing, and it requires hiding TARGET_SIGTRAP behind
a function call.

Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Message-Id: <20240202152506.279476-2-iii@linux.ibm.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20240207163812.3231697-11-alex.bennee@linaro.org>
2024-02-09 17:52:40 +00:00
Paolo Bonzini
1220f5813a meson: remove config_targetos
config_targetos is now empty and can be removed; its use in sourcesets
that do not involve target-specific files can be replaced with an empty
dictionary.

In fact, at this point *all* sourcesets that do not involve
target-specific files are just glorified mutable arrays.  Enforce that
they never test for symbols in "when:" by computing the set of files
without "strict: false".

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-12-31 09:11:28 +01:00
Alex Bennée
5dcf6334ae gdbstub: use a better signal when we halt for IO reasons
The gdb description GDB_SIGNAL_IO is "I/O possible" and by default gdb
will try and restart the guest, getting us nowhere. Report
GDB_SIGNAL_STOP instead which should at least halt the session at the
failure point.

Reviewed-by: Luis Machado <luis.machado@arm.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20231201093633.2551497-2-alex.bennee@linaro.org>
2023-12-01 14:00:52 +00:00
Michael Tokarev
ac2786f0b0 gdbstub: spelling fix: respectivelly
Fixes: 761e3c1088 "gdbstub: fixes cases where wrong threads were reported to GDB on SIGINT"
Reviewed-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
2023-11-15 11:09:17 +03:00
Akihiko Odaki
e84f45243f gdbstub: Introduce GDBFeatureBuilder
GDBFeatureBuilder unifies the logic to generate dynamic GDBFeature.

Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20231025093128.33116-4-akihiko.odaki@daynix.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20231106185112.2755262-11-alex.bennee@linaro.org>
2023-11-08 15:15:23 +00:00
Akihiko Odaki
1218b68ea6 gdbstub: Introduce gdb_find_static_feature()
This function is useful to determine the number of registers exposed to
GDB from the XML name.

Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20231025093128.33116-3-akihiko.odaki@daynix.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20231106185112.2755262-10-alex.bennee@linaro.org>
2023-11-08 15:15:23 +00:00
Akihiko Odaki
dbd6623ce7 gdbstub: Check if gdb_regs is NULL
cpu->gdb_regs may be NULL if no coprocessor is registered.

Fixes: 73c392c26b ("gdbstub: Replace gdb_regs with an array")
Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Message-Id: <20231029145033.592566-17-alex.bennee@linaro.org>
Message-Id: <20231019101030.128431-2-akihiko.odaki@daynix.com>
Tested-by: Fabiano Rosas <farosas@suse.de>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Tested-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
2023-10-31 14:10:21 +00:00
Clément Chigot
e216256ae9 gdbstub: replace exit calls with proper shutdown for softmmu
This replaces the exit calls by shutdown requests, ensuring a proper
cleanup of Qemu. Features like net/vhost-vdpa.c are expecting
qemu_cleanup to be called to remove their last residuals.

Signed-off-by: Clément Chigot <chigot@adacore.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-ID: <20231003071427.188697-6-chigot@adacore.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
2023-10-12 12:36:37 +10:00
Akihiko Odaki
73c392c26b gdbstub: Replace gdb_regs with an array
An array is a more appropriate data structure than a list for gdb_regs
since it is initialized only with append operation and read-only after
initialization.

Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20230912224107.29669-13-akihiko.odaki@daynix.com>
[AJB: fixed a checkpatch violation]
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20231009164104.369749-20-alex.bennee@linaro.org>
2023-10-11 08:46:33 +01:00
Akihiko Odaki
213316d401 gdbstub: Remove gdb_has_xml variable
GDB has XML support since 6.7 which was released in 2007.
It's time to remove support for old GDB versions without XML support.

Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20230912224107.29669-12-akihiko.odaki@daynix.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20231009164104.369749-19-alex.bennee@linaro.org>
2023-10-11 08:46:33 +01:00
Akihiko Odaki
6d8f77a6a1 gdbstub: Use g_markup_printf_escaped()
g_markup_printf_escaped() is a safer alternative to simple printf() as
it automatically escapes values.

Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Message-Id: <20230912224107.29669-9-akihiko.odaki@daynix.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20231009164104.369749-16-alex.bennee@linaro.org>
2023-10-11 08:46:33 +01:00
Akihiko Odaki
a650683871 hw/core/cpu: Return static value with gdb_arch_name()
All implementations of gdb_arch_name() returns dynamic duplicates of
static strings. It's also unlikely that there will be an implementation
of gdb_arch_name() that returns a truly dynamic value due to the nature
of the function returning a well-known identifiers. Qualify the value
gdb_arch_name() with const and make all of its implementations return
static strings.

Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20230912224107.29669-8-akihiko.odaki@daynix.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20231009164104.369749-15-alex.bennee@linaro.org>
2023-10-11 08:46:33 +01:00
Akihiko Odaki
956af7daad gdbstub: Introduce GDBFeature structure
Before this change, the information from a XML file was stored in an
array that is not descriptive. Introduce a dedicated structure type to
make it easier to understand and to extend with more fields.

Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20230912224107.29669-6-akihiko.odaki@daynix.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20231009164104.369749-13-alex.bennee@linaro.org>
2023-10-11 08:46:33 +01:00
Akihiko Odaki
5d1ab24206 gdbstub: Fix target.xml response
It was failing to return target.xml after the first request.

Fixes: 56e534bd11 ("gdbstub: refactor get_feature_xml")
Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Message-Id: <20230912224107.29669-3-akihiko.odaki@daynix.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20231009164104.369749-10-alex.bennee@linaro.org>
2023-10-11 08:46:33 +01:00
Akihiko Odaki
af2e06c9f1 gdbstub: Fix target_xml initialization
target_xml is no longer a fixed-length array but a pointer to a
variable-length memory.

Fixes: 56e534bd11 ("gdbstub: refactor get_feature_xml")
Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20230912224107.29669-2-akihiko.odaki@daynix.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20231009164104.369749-9-alex.bennee@linaro.org>
2023-10-11 08:46:33 +01:00
Philippe Mathieu-Daudé
3f7d1bdab0 gdbstub: Rename 'softmmu' -> 'system'
We have gdbstub/user.c for user emulation code,
use gdbstub/system.c for system emulation part.

Rename s/softmmu/system/ in meson and few comments.

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-ID: <20231004090629.37473-8-philmd@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-10-07 19:02:59 +02:00
Richard Henderson
b77af26e97 accel/tcg: Replace CPUState.env_ptr with cpu_env()
Reviewed-by: Anton Johansson <anjo@rev.ng>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2023-10-04 11:03:54 -07:00
Paolo Bonzini
4c545a05ab meson: clean up static_library keyword arguments
These are either built because they are dependencies of other targets,
or not needed at all because they are used via extract_objects().
Mark them as "build_by_default: false"; if applicable, mark them
as "fa" so that -Wl,--whole-archive does not interact with the
linker script used for fuzzing.

(The "fa" hack is brittle; updating to Meson 1.1 would allow using
declare_dependency(objects: ...) instead).

Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1044
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-09-29 09:33:10 +02:00
Paolo Bonzini
1f2146f7ca configure, meson: remove target OS symbols from config-host.mak
Stop applying config-host.mak to the sourcesets, since it does not
have any more CONFIG_* symbols coming from the command line.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-09-07 13:32:37 +02:00
Alex Bennée
8dd7a4b348 gdbstub: move comment for gdb_register_coprocessor
Use proper kdoc style comments for this API function.

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20230829161528.2707696-13-alex.bennee@linaro.org>
2023-08-30 14:57:59 +01:00
Alex Bennée
d0e5fa849d gdbstub: replace global gdb_has_xml with a function
Try and make the self reported global hack a little less hackish by
providing a query function instead. As gdb_has_xml was always set if
we negotiated XML we can now use the presence of ->target_xml as the
test instead.

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20230829161528.2707696-12-alex.bennee@linaro.org>
2023-08-30 14:57:56 +01:00
Alex Bennée
56e534bd11 gdbstub: refactor get_feature_xml
Try to bring up the code to more modern standards by:

  - use dynamic GString built xml over a fixed buffer
  - use autofree to save on explicit g_free() calls
  - don't hand hack strstr to find the delimiter
  - fix up style of xml_builtin and invert loop

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20230829161528.2707696-11-alex.bennee@linaro.org>
2023-08-30 14:57:56 +01:00
Alex Bennée
5b030993db gdbstub: remove unused user_ctx field
This was always NULL so drop it.

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Acked-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20230829161528.2707696-10-alex.bennee@linaro.org>
2023-08-30 14:57:50 +01:00
Matheus Branco Borella
761e3c1088 gdbstub: fixes cases where wrong threads were reported to GDB on SIGINT
This fix is implemented by having the vCont handler set the value of
`gdbserver_state.c_cpu` if any threads are to be resumed. The specific
CPU picked is arbitrarily from the ones to be resumed, but it should
be okay, as all GDB cares about is that it is a resumed thread.

Signed-off-by: Matheus Branco Borella <dark.ryu.550@gmail.com>
Message-Id: <20230804182633.47300-2-dark.ryu.550@gmail.com>
[AJB: style and whitespace fixes]
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1725
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20230829161528.2707696-9-alex.bennee@linaro.org>
2023-08-30 14:57:50 +01:00
Alex Bennée
f1b0f894c8 gdbstub: don't complain about preemptive ACK chars
When starting a remote connection GDB sends an '+':

  /* Ack any packet which the remote side has already sent.  */
  remote_serial_write ("+", 1);

which gets flagged as a garbage character in the gdbstub state
machine. As gdb does send it out lets be permissive about the handling
so we can better see real issues.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Cc: gdb-patches@sourceware.org
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-Id: <20230810153640.1879717-9-alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2023-08-10 11:04:34 -07:00
Alex Bennée
3869eb7eee gdbstub: more fixes for client Ctrl-C handling
The original fix caused problems with spurious characters on other
system emulation. So:

  - instead of spamming output make the warning a trace point
  - ensure we only allow a stop reply if it was 0x3

Suggested-by: Matheus Tavares Bernardino <quic_mathbern@quicinc.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <456ed3318421dd7946bdfb5ceda7e05332da368c.1690910333.git.quic_mathbern@quicinc.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Tested-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-Id: <20230810153640.1879717-8-alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2023-08-10 11:04:34 -07:00
Matheus Tavares Bernardino
6c78de6eb6 gdbstub: use 0 ("any process") on packets with no PID
Previously, qemu-user would always report PID 1 to GDB. This was changed
at dc14a7a6e9 (gdbstub: Report the actual qemu-user pid, 2023-06-30),
but read_thread_id() still considers GDB packets with "no PID" as "PID
1", which is not the qemu-user PID. Fix that by parsing "no PID" as "0",
which the GDB Remote Protocol defines as "any process".

Note that this should have no effect for system emulation as, in this
case, gdb_create_default_process() will assign PID 1 for the first
process and that is what the gdbstub uses for GDB requests with no PID,
or PID 0.

This issue was found with hexagon-lldb, which sends a "Hg" packet with
only the thread-id, but no process-id, leading to the invalid usage of
"PID 1" by qemu-hexagon and a subsequent "E22" reply.

Signed-off-by: Matheus Tavares Bernardino <quic_mathbern@quicinc.com>
Acked-by: Ilya Leoshkevich <iii@linux.ibm.com>
Message-Id: <78a3b06f6ab90a7ff8e73ae14a996eb27ec76c85.1690904195.git.quic_mathbern@quicinc.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2023-08-06 10:10:11 -07:00
Nicholas Piggin
108e8180c6 gdbstub: Fix client Ctrl-C handling
The gdb remote protocol has a special interrupt character (0x03) that is
transmitted outside the regular packet processing, and represents a
Ctrl-C pressed in the client. Despite not being a regular packet, it
does expect a regular stop response if the stub successfully stops the
running program.

See: https://sourceware.org/gdb/onlinedocs/gdb/Interrupts.html

Inhibiting the stop reply packet can lead to gdb client hang. So permit
a stop response when receiving a character from gdb that stops the vm.
Additionally, add a warning if that was not a 0x03 character, because
the gdb session is likely to end up getting confused if this happens.

Cc: qemu-stable@nongnu.org
Fixes: 758370052f ("gdbstub: only send stop-reply packets when allowed to")
Reported-by: Frederic Barrat <fbarrat@linux.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Tested-by: Joel Stanley <joel@jms.id.au>
Message-id: 20230711085903.304496-1-npiggin@gmail.com
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2023-07-31 14:57:32 +01:00
Ilya Leoshkevich
e282010b2e gdbstub: Add support for info proc mappings
Currently the GDB's generate-core-file command doesn't work well with
qemu-user: the resulting dumps are huge [1] and at the same time
incomplete (argv and envp are missing). The reason is that GDB has no
access to proc mappings and therefore has to fall back to using
heuristics for discovering them. This is, in turn, because qemu-user
does not implement the Host I/O feature of the GDB Remote Serial
Protocol.

Implement vFile:{open,close,pread,readlink} and also
qXfer:exec-file:read+. With that, generate-core-file begins to work on
aarch64 and s390x.

[1] https://sourceware.org/pipermail/gdb-patches/2023-May/199432.html

Co-developed-by: Dominik 'Disconnect3d' Czarnota <dominik.b.czarnota@gmail.com>
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Message-Id: <20230621203627.1808446-7-iii@linux.ibm.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20230630180423.558337-37-alex.bennee@linaro.org>
2023-07-03 12:52:34 +01:00
Ilya Leoshkevich
dc14a7a6e9 gdbstub: Report the actual qemu-user pid
Currently qemu-user reports pid 1 to GDB. Resolve the TODO and report
the actual PID. Using getpid() relies on the assumption that there is
only one GDBProcess. Add an assertion to make sure that future changes
don't break it.

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Message-Id: <20230621203627.1808446-6-iii@linux.ibm.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20230630180423.558337-36-alex.bennee@linaro.org>
2023-07-03 12:52:34 +01:00
Ilya Leoshkevich
a3fcc111fa gdbstub: Expose gdb_get_process() and gdb_get_first_cpu_in_process()
These functions will be needed by user-target.c in order to retrieve
the name of the executable.

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Message-Id: <20230621203627.1808446-5-iii@linux.ibm.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20230630180423.558337-35-alex.bennee@linaro.org>
2023-07-03 12:52:34 +01:00
Alex Bennée
2261b73c28 gdbstub: clean-up vcont handling to avoid goto
We can handle all the error exit cases by using g_autofree() for the
one thing that needs cleaning up on the exit.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20230630180423.558337-31-alex.bennee@linaro.org>
2023-07-03 12:52:30 +01:00
Nicholas Piggin
3b72d68162 gdbstub: Permit reverse step/break to provide stop response
The final part of the reverse step and break handling is to bring
the machine back to a debug stop state. gdb expects a response.

A gdb 'rsi' command hangs forever because the gdbstub filters out
the response (also observable with reverse_debugging.py avocado
tests).

Fix by setting allow_stop_reply for the gdb backward packets.

Fixes: 758370052f ("gdbstub: only send stop-reply packets when allowed to")
Cc: qemu-stable@nongnu.org
Cc: Matheus Tavares Bernardino <quic_mathbern@quicinc.com>
Cc: Alex Bennée <alex.bennee@linaro.org>
Cc: Taylor Simpson <tsimpson@quicinc.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Acked-by: Matheus Tavares Bernardino <quic_mathbern@quicinc.com>
Message-Id: <20230623035304.279833-1-npiggin@gmail.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20230630180423.558337-30-alex.bennee@linaro.org>
2023-07-03 12:52:30 +01:00
Alex Bennée
d2fe226467 gdbstub: lightly refactor connection to avoid snprintf
This may be a bit too much to avoid an snprintf and the slightly dodgy
assign to a const variable. But hopefully not.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20230630180423.558337-29-alex.bennee@linaro.org>
2023-07-03 12:52:30 +01:00
Philippe Mathieu-Daudé
de6cd7599b meson: Replace softmmu_ss -> system_ss
We use the user_ss[] array to hold the user emulation sources,
and the softmmu_ss[] array to hold the system emulation ones.
Hold the latter in the 'system_ss[]' array for parity with user
emulation.

Mechanical change doing:

  $ sed -i -e s/softmmu_ss/system_ss/g $(git grep -l softmmu_ss)

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20230613133347.82210-10-philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2023-06-20 10:01:30 +02:00
Matheus Tavares Bernardino
758370052f gdbstub: only send stop-reply packets when allowed to
GDB's remote serial protocol allows stop-reply messages to be sent by
the stub either as a notification packet or as a reply to a GDB command
(provided that the cmd accepts such a response). QEMU currently does not
implement notification packets, so it should only send stop-replies
synchronously and when requested. Nevertheless, it still issues
unsolicited stop messages through gdb_vm_state_change().

Although this behavior doesn't seem to cause problems with GDB itself
(the messages are just ignored), it can impact other debuggers that
implement the GDB remote serial protocol, like hexagon-lldb. Let's
change the gdbstub to send stop messages only as a response to a
previous GDB command that accepts such a reply.

Signed-off-by: Matheus Tavares Bernardino <quic_mathbern@quicinc.com>
Acked-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Taylor Simpson <tsimpson@quicinc.com>
Message-Id: <a49c0897fc22a6a7827c8dfc32aef2e1d933ec6b.1683214375.git.quic_mathbern@quicinc.com>
2023-05-18 12:40:52 -07:00
Alex Bennée
0beaebc041 gdbstub: don't report auxv feature unless on Linux
The later handler if conditionally compiled only for Linux but we
forgot to ensure we don't advertise it lest we confuse our BSD
brethren.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Fixes: 51c623b0de ("gdbstub: add support to Xfer:auxv:read: packet")
Reported-by: Warner Losh <imp@bsdimp.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Warner Losh <imp@bsdimp.com>
Tested-by: Warner Losh <imp@bsdimp.com>
Message-Id: <20230403134920.2132362-4-alex.bennee@linaro.org>
2023-04-04 15:56:44 +01:00
Philippe Mathieu-Daudé
b846ad627e gdbstub: Only build libgdb_user.fa / libgdb_softmmu.fa if necessary
It is pointless to build libgdb_user.fa in a system-only build
(or libgdb_softmmu.fa in a user-only build). Besides, in some
restricted build configurations, some APIs might be restricted /
not available. Example in a KVM-only builds where TCG is disabled:

  $ ninja qemu-system-x86_64
  [99/2187] Compiling C object gdbstub/libgdb_user.fa.p/user.c.o
  FAILED: gdbstub/libgdb_user.fa.p/user.c.o
  ../../gdbstub/user.c: In function ‘gdb_breakpoint_insert’:
  ../../gdbstub/user.c:438:19: error: implicit declaration of function ‘cpu_breakpoint_insert’; did you mean ‘gdb_breakpoint_insert’? [-Werror=implicit-function-declaration]
    438 |             err = cpu_breakpoint_insert(cpu, addr, BP_GDB, NULL);
        |                   ^~~~~~~~~~~~~~~~~~~~~
        |                   gdb_breakpoint_insert
  ../../gdbstub/user.c:438:19: error: nested extern declaration of ‘cpu_breakpoint_insert’ [-Werror=nested-externs]
  ../../gdbstub/user.c: In function ‘gdb_breakpoint_remove’:
  ../../gdbstub/user.c:459:19: error: implicit declaration of function ‘cpu_breakpoint_remove’; did you mean ‘gdb_breakpoint_remove’? [-Werror=implicit-function-declaration]
    459 |             err = cpu_breakpoint_remove(cpu, addr, BP_GDB);
        |                   ^~~~~~~~~~~~~~~~~~~~~
        |                   gdb_breakpoint_remove
  ../../gdbstub/user.c:459:19: error: nested extern declaration of ‘cpu_breakpoint_remove’ [-Werror=nested-externs]
  cc1: all warnings being treated as errors
  ninja: build stopped: subcommand failed.

Fixes: 61b2e136db ("gdbstub: only compile gdbstub twice for whole build")
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20230329161852.84992-1-philmd@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20230403134920.2132362-3-alex.bennee@linaro.org>
2023-04-04 15:56:37 +01:00
Richard Henderson
cc37d98bfb *: Add missing includes of qemu/error-report.h
This had been pulled in via qemu/plugin.h from hw/core/cpu.h,
but that will be removed.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-Id: <20230310195252.210956-5-richard.henderson@linaro.org>
[AJB: add various additional cases shown by CI]
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20230315174331.2959-15-alex.bennee@linaro.org>
Reviewed-by: Emilio Cota <cota@braap.org>
2023-03-22 15:06:57 +00:00