gdbstub: Add helper function to unregister GDB register space

Add common function to help unregister the GDB register space. This shall be
done in context to the CPU unrealization.

Note: These are

gdbstub: Add helper function to unregister GDB register space

Add common function to help unregister the GDB register space. This shall be
done in context to the CPU unrealization.

Note: These are common functions exported to arch specific code. For example,
for ARM this code is being referred in associated arch specific patch-set:

Link: https://lore.kernel.org/qemu-devel/20230926103654.34424-1-salil.mehta@huawei.com/

Signed-off-by: Salil Mehta <salil.mehta@huawei.com>
Tested-by: Vishnu Pajjuri <vishnu@os.amperecomputing.com>
Reviewed-by: Gavin Shan <gshan@redhat.com>
Tested-by: Xianglai Li <lixianglai@loongson.cn>
Tested-by: Miguel Luis <miguel.luis@oracle.com>
Reviewed-by: Shaoqin Huang <shahuang@redhat.com>
Reviewed-by: Vishnu Pajjuri <vishnu@os.amperecomputing.com>
Tested-by: Zhao Liu <zhao1.liu@intel.com>
Acked-by: Igor Mammedov <imammedo@redhat.com>
Message-Id: <20240716111502.202344-8-salil.mehta@huawei.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

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gdbstub: Re-factor gdb command extensions

Coverity reported a memory leak (CID 1549757) in this code and its
admittedly rather clumsy handling of extending the command table.
Instead of handing over

gdbstub: Re-factor gdb command extensions

Coverity reported a memory leak (CID 1549757) in this code and its
admittedly rather clumsy handling of extending the command table.
Instead of handing over a full array of the commands lets use the
lighter weight GPtrArray and simply test for the presence of each
entry as we go. This avoids complications of transferring ownership of
arrays and keeps the final command entries as static entries in the
target code.

Cc: Akihiko Odaki <akihiko.odaki@daynix.com>
Cc: Gustavo Bueno Romero <gustavo.romero@linaro.org>
Cc: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Gustavo Romero <gustavo.romero@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20240718094523.1198645-4-alex.bennee@linaro.org>

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gdbstub: Use true to set cmd_startswith

cmd_startswith is a boolean so use 'true' to set it instead of 1.

Signed-off-by: Gustavo Romero <gustavo.romero@linaro.org>
Message-Id: <20240628050850.53644

gdbstub: Use true to set cmd_startswith

cmd_startswith is a boolean so use 'true' to set it instead of 1.

Signed-off-by: Gustavo Romero <gustavo.romero@linaro.org>
Message-Id: <20240628050850.536447-10-gustavo.romero@linaro.org>
Reviewed-by: Manos Pitsidianakis <manos.pitsidianakis@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20240705084047.857176-39-alex.bennee@linaro.org>

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gdbstub: Pass CPU context to command handler

Allow passing the current CPU context to command handlers via user_ctx
when the handler requires it.

Signed-off-by: Gustavo Romero <gustavo.romero@linar

gdbstub: Pass CPU context to command handler

Allow passing the current CPU context to command handlers via user_ctx
when the handler requires it.

Signed-off-by: Gustavo Romero <gustavo.romero@linaro.org>
Message-Id: <20240628050850.536447-9-gustavo.romero@linaro.org>
Reviewed-by: Manos Pitsidianakis <manos.pitsidianakis@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20240705084047.857176-38-alex.bennee@linaro.org>

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gdbstub: Make hex conversion function non-internal

Make gdb_hextomem non-internal so it's not confined to use only in
gdbstub.c.

Signed-off-by: Gustavo Romero <gustavo.romero@linaro.org>
Reviewed-b

gdbstub: Make hex conversion function non-internal

Make gdb_hextomem non-internal so it's not confined to use only in
gdbstub.c.

Signed-off-by: Gustavo Romero <gustavo.romero@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20240628050850.536447-8-gustavo.romero@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20240705084047.857176-37-alex.bennee@linaro.org>

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gdbstub: Add support for target-specific stubs

Currently, it's not possible to have stubs specific to a given target,
even though there are GDB features which are target-specific, like, for
instance

gdbstub: Add support for target-specific stubs

Currently, it's not possible to have stubs specific to a given target,
even though there are GDB features which are target-specific, like, for
instance, memory tagging.

This commit introduces gdb_extend_qsupported_features,
gdb_extend_query_table, and gdb_extend_set_table functions as interfaces
to extend the qSupported string, the query handler table, and the set
handler table, allowing target-specific stub implementations.

Signed-off-by: Gustavo Romero <gustavo.romero@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20240628050850.536447-4-gustavo.romero@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20240705084047.857176-33-alex.bennee@linaro.org>

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gdbstub: Move GdbCmdParseEntry into a new header file

Move GdbCmdParseEntry and its associated types into a separate header
file to allow the use of GdbCmdParseEntry and other gdbstub command
functi

gdbstub: Move GdbCmdParseEntry into a new header file

Move GdbCmdParseEntry and its associated types into a separate header
file to allow the use of GdbCmdParseEntry and other gdbstub command
functions outside of gdbstub.c.

Since GdbCmdParseEntry and get_param are now public, kdoc
GdbCmdParseEntry and rename get_param to gdb_get_cmd_param.

This commit also makes gdb_put_packet public since is used in gdbstub
command handling.

Signed-off-by: Gustavo Romero <gustavo.romero@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20240628050850.536447-3-gustavo.romero@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20240705084047.857176-32-alex.bennee@linaro.org>

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gdbstub: Clean up process_string_cmd

Change 'process_string_cmd' to return true on success and false on
failure, instead of 0 and -1.

Signed-off-by: Gustavo Romero <gustavo.romero@linaro.org>
Revie

gdbstub: Clean up process_string_cmd

Change 'process_string_cmd' to return true on success and false on
failure, instead of 0 and -1.

Signed-off-by: Gustavo Romero <gustavo.romero@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-Id: <20240628050850.536447-2-gustavo.romero@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20240705084047.857176-31-alex.bennee@linaro.org>

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meson: Drop the .fa library suffix

The non-standard .fa library suffix breaks the link source
de-duplication done by Meson so drop it.

The lack of link source de-duplication causes AddressSanitizer

meson: Drop the .fa library suffix

The non-standard .fa library suffix breaks the link source
de-duplication done by Meson so drop it.

The lack of link source de-duplication causes AddressSanitizer to
complain ODR violations, and makes GNU ld abort when combined with
clang's LTO.

Fortunately, the non-standard suffix is not necessary anymore for
two reasons.

First, the non-standard suffix was necessary for fork-fuzzing.
Meson wraps all standard-suffixed libraries with --start-group and
--end-group. This made a fork-fuzz.ld linker script wrapped as well and
broke builds. Commit d2e6f9272d33 ("fuzz: remove fork-fuzzing
scaffolding") dropped fork-fuzzing so we can now restore the standard
suffix.

Second, the libraries are not even built anymore, because it is
possible to just use the object files directly via extract_all_objects().

The occurences of the suffix were detected and removed by performing
a tree-wide search with 'fa' and .fa (note the quotes and dot).

Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Message-ID: <20240524-xkb-v4-4-2de564e5c859@daynix.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

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meson: Pass objects and dependencies to declare_dependency()

We used to request declare_dependency() to link_whole static libraries.
If a static library is a thin archive, GNU ld keeps all object fi

meson: Pass objects and dependencies to declare_dependency()

We used to request declare_dependency() to link_whole static libraries.
If a static library is a thin archive, GNU ld keeps all object files
referenced by the archive open, and sometimes exceeds the open file limit.

Another problem with link_whole is that suboptimal handling of nested
dependencies.

link_whole by itself does not propagate dependencies. In particular,
gnutls, a dependency of crypto, is not propagated to its users, and we
currently workaround the issue by declaring gnutls as a dependency for
each crypto user. On the other hand, if you write something like

libfoo = static_library('foo', 'foo.c', dependencies: gnutls)
foo = declare_dependency(link_whole: libfoo)

libbar = static_library('bar', 'bar.c', dependencies: foo)
bar = declare_dependency(link_whole: libbar, dependencies: foo)
executable('prog', sources: files('prog.c'), dependencies: [foo, bar])

hoping to propagate the gnutls dependency into bar.c, you'll see a
linking failure for "prog", because the foo.c.o object file is included in
libbar.a and therefore it is linked twice into "prog": once from libfoo.a
and once from libbar.a. Here Meson does not see the duplication, it
just asks the linker to link all of libfoo.a and libbar.a into "prog".

Instead of using link_whole, extract objects included in static libraries
and pass them to declare_dependency(); and then the dependencies can be
added as well so that they are propagated, because object files on the
linker command line are always deduplicated.

This requires Meson 1.1.0 or later.

Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Message-ID: <20240524-objects-v1-1-07cbbe96166b@daynix.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

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gdbstub: move enums into separate header

This is an experiment to further reduce the amount we throw into the
exec headers. It might not be as useful as I initially thought because
just under half o

gdbstub: move enums into separate header

This is an experiment to further reduce the amount we throw into the
exec headers. It might not be as useful as I initially thought because
just under half of the users also need gdbserver_start().

Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20240620152220.2192768-3-alex.bennee@linaro.org>

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user: Use get_task_state() helper

Get the TaskState pointer calling get_task_state().

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@lin

user: Use get_task_state() helper

Get the TaskState pointer calling get_task_state().

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20240428221450.26460-11-philmd@linaro.org>

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gdbstub: Include missing 'hw/core/cpu.h' header

Functions such gdb_get_cpu_pid() dereference CPUState so
require the structure declaration from "hw/core/cpu.h":

static uint32_t gdb_get_cpu_pid(CP

gdbstub: Include missing 'hw/core/cpu.h' header

Functions such gdb_get_cpu_pid() dereference CPUState so
require the structure declaration from "hw/core/cpu.h":

static uint32_t gdb_get_cpu_pid(CPUState *cpu)
{
...
return cpu->cluster_index + 1;
}

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Warner Losh <imp@bsdimp.com>
Message-Id: <20231211212003.21686-15-philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>

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gdbstub/system: Rename 'user_ctx' argument as 'ctx'

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <2024031321333

gdbstub/system: Rename 'user_ctx' argument as 'ctx'

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20240313213339.82071-4-philmd@linaro.org>

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gdbstub: Correct invalid mentions of 'softmmu' by 'system'

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Richard Henderson <richa

gdbstub: Correct invalid mentions of 'softmmu' by 'system'

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20240313213339.82071-3-philmd@linaro.org>

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gdbstub: Fix double close() of the follow-fork-mode socket

When the terminal GDB_FORK_ENABLED state is reached, the coordination
socket is not needed anymore and is therefore closed. However, if the

gdbstub: Fix double close() of the follow-fork-mode socket

When the terminal GDB_FORK_ENABLED state is reached, the coordination
socket is not needed anymore and is therefore closed. However, if there
is a communication error between QEMU gdbstub and GDB, the generic
error handling code attempts to close it again.

Fix by closing it later - before returning - instead.

Fixes: Coverity CID 1539966
Fixes: d547e711a8a5 ("gdbstub: Implement follow-fork-mode child")
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20240312001813.13720-1-iii@linux.ibm.com>

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gdbstub: Add Xfer:siginfo:read stub

Add stub to handle Xfer:siginfo:read packet query that requests the
machine's siginfo data.

This is used when GDB user executes 'print $_siginfo' and when the
ma

gdbstub: Add Xfer:siginfo:read stub

Add stub to handle Xfer:siginfo:read packet query that requests the
machine's siginfo data.

This is used when GDB user executes 'print $_siginfo' and when the
machine stops due to a signal, for instance, on SIGSEGV. The information
in siginfo allows GDB to determiner further details on the signal, like
the fault address/insn when the SIGSEGV is caught.

Signed-off-by: Gustavo Romero <gustavo.romero@linaro.org>
Message-Id: <20240309030901.1726211-5-gustavo.romero@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>

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gdbstub: Save target's siginfo

Save target's siginfo into gdbserver_state so it can be used later, for
example, in any stub that requires the target's si_signo and si_code.

This change affects only

gdbstub: Save target's siginfo

Save target's siginfo into gdbserver_state so it can be used later, for
example, in any stub that requires the target's si_signo and si_code.

This change affects only linux-user mode.

Signed-off-by: Gustavo Romero <gustavo.romero@linaro.org>
Suggested-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20240309030901.1726211-4-gustavo.romero@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>

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gdbstub: Rename back gdb_handlesig

Rename gdb_handlesig_reason back to gdb_handlesig. There is no need to
add a wrapper for gdb_handlesig and rename it when a new parameter is
added.

Signed-off-by:

gdbstub: Rename back gdb_handlesig

Rename gdb_handlesig_reason back to gdb_handlesig. There is no need to
add a wrapper for gdb_handlesig and rename it when a new parameter is
added.

Signed-off-by: Gustavo Romero <gustavo.romero@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20240309030901.1726211-2-gustavo.romero@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>

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gdbstub: Implement follow-fork-mode child

Currently it's not possible to use gdbstub for debugging linux-user
code that runs in a forked child, which is normally done using the `set
follow-fork-mode

gdbstub: Implement follow-fork-mode child

Currently it's not possible to use gdbstub for debugging linux-user
code that runs in a forked child, which is normally done using the `set
follow-fork-mode child` GDB command. Purely on the protocol level, the
missing piece is the fork-events feature.

However, a deeper problem is supporting $Hg switching between different
processes - right now it can do only threads. Implementing this for the
general case would be quite complicated, but, fortunately, for the
follow-fork-mode case there are a few factors that greatly simplify
things: fork() happens in the exclusive section, there are only two
processes involved, and before one of them is resumed, the second one
is detached.

This makes it possible to implement a simplified scheme: the parent and
the child share the gdbserver socket, it's used only by one of them at
any given time, which is coordinated through a separate socketpair. The
processes can read from the gdbserver socket only one byte at a time,
which is not great for performance, but, fortunately, the
follow-fork-mode handling involves only a few messages.

Advertise the fork-events support, and remember whether GDB has it
as well. Implement the state machine that is initialized on fork(),
decides the current owner of the gdbserver socket, and is terminated
when one of the two processes is detached. The logic for the parent and
the child is the same, only the initial state is different.

Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Message-Id: <20240219141628.246823-12-iii@linux.ibm.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20240305121005.3528075-13-alex.bennee@linaro.org>

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gdbstub: Introduce gdb_handle_detach_user()

The upcoming follow-fork-mode child support needs to perform certain
actions when GDB detaches from the stopped parent or the stopped child.
Introduce a u

gdbstub: Introduce gdb_handle_detach_user()

The upcoming follow-fork-mode child support needs to perform certain
actions when GDB detaches from the stopped parent or the stopped child.
Introduce a user-specific hook for this.

Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Message-Id: <20240219141628.246823-11-iii@linux.ibm.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20240305121005.3528075-12-alex.bennee@linaro.org>

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gdbstub: Introduce gdb_handle_set_thread_user()

The upcoming follow-fork-mode child support needs to perform certain
actions when GDB switches between the stopped parent and the stopped
child. Intro

gdbstub: Introduce gdb_handle_set_thread_user()

The upcoming follow-fork-mode child support needs to perform certain
actions when GDB switches between the stopped parent and the stopped
child. Introduce a user-specific hook for this.

Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Message-Id: <20240219141628.246823-10-iii@linux.ibm.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20240305121005.3528075-11-alex.bennee@linaro.org>

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gdbstub: Introduce gdb_handle_query_supported_user()

The upcoming follow-fork-mode child support requires advertising the
fork-events feature, which is user-specific. Introduce a user-specific
hook

gdbstub: Introduce gdb_handle_query_supported_user()

The upcoming follow-fork-mode child support requires advertising the
fork-events feature, which is user-specific. Introduce a user-specific
hook for this.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Message-Id: <20240219141628.246823-9-iii@linux.ibm.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20240305121005.3528075-10-alex.bennee@linaro.org>

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gdbstub: Call gdbserver_fork() both in parent and in child

The upcoming follow-fork-mode child support requires post-fork message
exchange between the parent and the child. Prepare gdbserver_fork()

gdbstub: Call gdbserver_fork() both in parent and in child

The upcoming follow-fork-mode child support requires post-fork message
exchange between the parent and the child. Prepare gdbserver_fork() for
this purpose. Rename it to gdbserver_fork_end() to better reflect its
purpose.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Message-Id: <20240219141628.246823-8-iii@linux.ibm.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20240305121005.3528075-9-alex.bennee@linaro.org>

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