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2023-08-10gdbstub: don't complain about preemptive ACK charsAlex Bennée
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>
2023-08-10gdbstub: more fixes for client Ctrl-C handlingAlex Bennée
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>
2023-08-06gdbstub: use 0 ("any process") on packets with no PIDMatheus Tavares Bernardino
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>
2023-07-31gdbstub: Fix client Ctrl-C handlingNicholas Piggin
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: 758370052fb ("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>
2023-07-03gdbstub: Add support for info proc mappingsIlya Leoshkevich
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>
2023-07-03gdbstub: Report the actual qemu-user pidIlya Leoshkevich
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>
2023-07-03gdbstub: Expose gdb_get_process() and gdb_get_first_cpu_in_process()Ilya Leoshkevich
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>
2023-07-03gdbstub: clean-up vcont handling to avoid gotoAlex Bennée
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>
2023-07-03gdbstub: Permit reverse step/break to provide stop responseNicholas Piggin
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: 758370052fb ("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>
2023-05-18gdbstub: only send stop-reply packets when allowed toMatheus Tavares Bernardino
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>
2023-04-04gdbstub: don't report auxv feature unless on LinuxAlex Bennée
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>
2023-03-22*: Add missing includes of qemu/error-report.hRichard Henderson
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>
2023-03-07gdbstub: only compile gdbstub twice for whole buildAlex Bennée
Now we have removed any target specific bits from the core gdbstub code we only need to build it twice. We have to jump a few meson hoops to manually define the CONFIG_USER_ONLY symbol but it seems to work. Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Signed-off-by: Alex Bennée <alex.bennee@linaro.org> Message-Id: <20230302190846.2593720-23-alex.bennee@linaro.org> Message-Id: <20230303025805.625589-23-richard.henderson@linaro.org>
2023-03-07gdbstub: move syscall handling to new fileAlex Bennée
Our GDB syscall support is the last chunk of code that needs target specific support so move it to a new file. We take the opportunity to move the syscall state into its own singleton instance and add in a few helpers for the main gdbstub to interact with the module. I also moved the gdb_exit() declaration into syscalls.h as it feels pretty related and most of the callers of it treat it as such. Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Signed-off-by: Alex Bennée <alex.bennee@linaro.org> Message-Id: <20230302190846.2593720-22-alex.bennee@linaro.org> Message-Id: <20230303025805.625589-22-richard.henderson@linaro.org>
2023-03-07gdbstub: don't use target_ulong while handling registersAlex Bennée
This is a hangover from the original code. addr is misleading as it is only really a register id. While len will never exceed MAX_PACKET_LENGTH I've used size_t as that is what strlen returns. 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: <20230302190846.2593720-20-alex.bennee@linaro.org> Message-Id: <20230303025805.625589-20-richard.henderson@linaro.org>
2023-03-07gdbstub: fix address type of gdb_set_cpu_pcAlex Bennée
The underlying call uses vaddr and the comms API uses unsigned long long which will always fit. We don't need to deal in target_ulong here. 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: <20230302190846.2593720-19-alex.bennee@linaro.org> Message-Id: <20230303025805.625589-19-richard.henderson@linaro.org>
2023-03-07gdbstub: specialise stub_can_reverseAlex Bennée
Currently we only support replay for softmmu mode so it is a constant false for user-mode. 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: <20230302190846.2593720-18-alex.bennee@linaro.org> Message-Id: <20230303025805.625589-18-richard.henderson@linaro.org>
2023-03-07gdbstub: introduce gdb_get_max_cpusAlex Bennée
This is needed for handling vcont packets as the way of calculating max cpus vhanges between user and softmmu mode. Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Signed-off-by: Alex Bennée <alex.bennee@linaro.org> Message-Id: <20230302190846.2593720-17-alex.bennee@linaro.org> Message-Id: <20230303025805.625589-17-richard.henderson@linaro.org>
2023-03-07gdbstub: specialise target_memory_rw_debugAlex Bennée
The two implementations are different enough to encourage having a specialisation and we can move some of the softmmu only stuff out of gdbstub. Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Signed-off-by: Alex Bennée <alex.bennee@linaro.org> Message-Id: <20230302190846.2593720-16-alex.bennee@linaro.org> Message-Id: <20230303025805.625589-16-richard.henderson@linaro.org>
2023-03-07gdbstub: specialise handle_query_attachedAlex Bennée
In both user and softmmu cases we are just replying with a constant. 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: <20230302190846.2593720-15-alex.bennee@linaro.org> Message-Id: <20230303025805.625589-15-richard.henderson@linaro.org>
2023-03-07gdbstub: abstract target specific details from gdb_put_packet_binaryAlex Bennée
We unfortunately handle the checking of packet acknowledgement differently for user and softmmu modes. Abstract the user mode stuff behind gdb_got_immediate_ack with a stub for softmmu. 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: <20230302190846.2593720-14-alex.bennee@linaro.org> Message-Id: <20230303025805.625589-14-richard.henderson@linaro.org>
2023-03-07gdbstub: move chunks of user code into own filesAlex Bennée
The process was pretty similar to the softmmu move except we take the time to split stuff between user.c and user-target.c to avoid as much target specific compilation as possible. We also start to make use of our shiny new header scheme so the user-only helpers can be included without the rest of the exec/gsbstub.h cruft. As before we split some functions into user and softmmu versions Reviewed-by: Fabiano Rosas <farosas@suse.de> Signed-off-by: Alex Bennée <alex.bennee@linaro.org> Message-Id: <20230302190846.2593720-12-alex.bennee@linaro.org> Message-Id: <20230303025805.625589-12-richard.henderson@linaro.org>
2023-03-07gdbstub: move chunk of softmmu functionality to own fileAlex Bennée
This is mostly code motion but a number of things needed to be done for this minimal patch set: - move shared structures to internals.h - splitting some functions into user and softmmu versions - fixing a few casting issues to keep softmmu common More CONFIG_USER_ONLY stuff will be handled in a following patches. Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Reviewed-by: Fabiano Rosas <farosas@suse.de> Signed-off-by: Alex Bennée <alex.bennee@linaro.org> Message-Id: <20230302190846.2593720-11-alex.bennee@linaro.org> Message-Id: <20230303025805.625589-11-richard.henderson@linaro.org>
2023-03-07gdbstub: make various helpers visible to the rest of the moduleAlex Bennée
We will be needing to use these helpers between the user and softmmu files so declare them in the headers, add a system prefix and remove static from the implementations. 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: <20230302190846.2593720-10-alex.bennee@linaro.org> Message-Id: <20230303025805.625589-10-richard.henderson@linaro.org>
2023-03-07gdbstub: move fromhex/tohex routines to internalsAlex Bennée
These will be needed from multiple places in the code. They are declared as inline so move to the header and fix up to modern coding style. The only other place that messes with hex stuff at the moment is the URI handling in utils but that would be more code churn so leave for now. Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Signed-off-by: Alex Bennée <alex.bennee@linaro.org> Message-Id: <20230302190846.2593720-9-alex.bennee@linaro.org> Message-Id: <20230303025805.625589-9-richard.henderson@linaro.org>
2023-03-07includes: move tb_flush into its own headerAlex Bennée
This aids subsystems (like gdbstub) that want to trigger a flush without pulling target specific headers. Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Signed-off-by: Alex Bennée <alex.bennee@linaro.org> Message-Id: <20230302190846.2593720-8-alex.bennee@linaro.org> Message-Id: <20230303025805.625589-8-richard.henderson@linaro.org>
2023-03-07gdbstub: move GDBState to shared internals headerAlex Bennée
We are about to split softmmu and user mode helpers into different files. To facilitate this we will need to share access to the GDBState between those files. Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Signed-off-by: Alex Bennée <alex.bennee@linaro.org> Message-Id: <20230302190846.2593720-7-alex.bennee@linaro.org> Message-Id: <20230303025805.625589-7-richard.henderson@linaro.org>
2023-03-07gdbstub: define separate user/system structuresAlex Bennée
In preparation for moving user/softmmu specific bits from the main gdbstub file we need to separate the connection details into a user/softmmu state. As these will eventually be defined in their own files we move them out of the common GDBState structure. Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Signed-off-by: Alex Bennée <alex.bennee@linaro.org> Message-Id: <20230302190846.2593720-6-alex.bennee@linaro.org> Message-Id: <20230303025805.625589-6-richard.henderson@linaro.org>
2023-03-07gdbstub: clean-up indent on gdb_exitAlex Bennée
Otherwise checkpatch will throw a hissy fit on the later patches that split this function up. Signed-off-by: Alex Bennée <alex.bennee@linaro.org> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Reviewed-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com> Message-Id: <20230302190846.2593720-5-alex.bennee@linaro.org> Message-Id: <20230303025805.625589-5-richard.henderson@linaro.org>
2023-02-27replay: Extract core API to 'exec/replay-core.h'Philippe Mathieu-Daudé
replay API is used deeply within TCG common code (common to user and system emulation). Unfortunately "sysemu/replay.h" requires some QAPI headers for few system-specific declarations, example: void replay_input_event(QemuConsole *src, InputEvent *evt); Since commit c2651c0eaa ("qapi/meson: Restrict UI module to system emulation and tools") the QAPI header defining the InputEvent is not generated anymore. To keep it simple, extract the 'core' replay prototypes to a new "exec/replay-core.h" header which we include in the TCG code that doesn't need the rest of the replay API. Reviewed-by: Pavel Dovgalyuk <Pavel.Dovgalyuk@ispras.ru> Message-Id: <20221219170806.60580-5-philmd@linaro.org> Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
2023-02-27gdbstub: Use vaddr type for generic insert/remove_breakpoint() APIPhilippe Mathieu-Daudé
Both insert/remove_breakpoint() handlers are used in system and user emulation. We can not use the 'hwaddr' type on user emulation, we have to use 'vaddr' which is defined as "wide enough to contain any #target_ulong virtual address". gdbstub.c doesn't require to include "exec/hwaddr.h" anymore. Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Reviewed-by: Fabiano Rosas <farosas@suse.de> Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org> Message-Id: <20221216215519.5522-4-philmd@linaro.org>
2022-10-06gdbstub: move guest debug support check to opsAlex Bennée
This removes the final hard coding of kvm_enabled() in gdbstub and moves the check to an AccelOps. Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Signed-off-by: Alex Bennée <alex.bennee@linaro.org> Reviewed-by: Mads Ynddal <mads@ynddal.dk> Message-Id: <20220929114231.583801-46-alex.bennee@linaro.org>
2022-10-06gdbstub: move breakpoint logic to accel opsAlex Bennée
As HW virtualization requires specific support to handle breakpoints lets push out special casing out of the core gdbstub code and into AccelOpsClass. This will make it easier to add other accelerator support and reduces some of the stub shenanigans. Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Signed-off-by: Alex Bennée <alex.bennee@linaro.org> Reviewed-by: Mads Ynddal <mads@ynddal.dk> Message-Id: <20220929114231.583801-45-alex.bennee@linaro.org>
2022-10-06gdbstub: move sstep flags probing into AccelClassAlex Bennée
The support of single-stepping is very much dependent on support from the accelerator we are using. To avoid special casing in gdbstub move the probing out to an AccelClass function so future accelerators can put their code there. Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Signed-off-by: Alex Bennée <alex.bennee@linaro.org> Reviewed-by: Mads Ynddal <mads@ynddal.dk> Message-Id: <20220929114231.583801-44-alex.bennee@linaro.org>
2022-10-06gdbstub: move into its own sub directoryAlex Bennée
This is in preparation of future refactoring as well as cleaning up the source tree. Aside from the minor tweaks to meson and trace.h this is pure code motion. Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Signed-off-by: Alex Bennée <alex.bennee@linaro.org> Message-Id: <20220929114231.583801-43-alex.bennee@linaro.org>