# SPDX-License-Identifier: GPL-2.0-only config HAVE_ARCH_KGDB bool # set if architecture has the its kgdb_arch_handle_qxfer_pkt # function to enable gdb stub to address XML packet sent from GDB. config HAVE_ARCH_KGDB_QXFER_PKT bool menuconfig KGDB bool "KGDB: kernel debugger" depends on HAVE_ARCH_KGDB depends on DEBUG_KERNEL help If you say Y here, it will be possible to remotely debug the kernel using gdb. It is recommended but not required, that you also turn on the kernel config option CONFIG_FRAME_POINTER to aid in producing more reliable stack backtraces in the external debugger. Documentation of kernel debugger is available at http://kgdb.sourceforge.net as well as in Documentation/dev-tools/kgdb.rst. If unsure, say N. if KGDB config KGDB_HONOUR_BLOCKLIST bool "KGDB: use kprobe blocklist to prohibit unsafe breakpoints" depends on HAVE_KPROBES depends on MODULES select KPROBES default y help If set to Y the debug core will use the kprobe blocklist to identify symbols where it is unsafe to set breakpoints. In particular this disallows instrumentation of functions called during debug trap handling and thus makes it very difficult to inadvertently provoke recursive trap handling. If unsure, say Y. config KGDB_SERIAL_CONSOLE tristate "KGDB: use kgdb over the serial console" select CONSOLE_POLL select MAGIC_SYSRQ depends on TTY && HW_CONSOLE default y help Share a serial console with kgdb. Sysrq-g must be used to break in initially. config KGDB_TESTS bool "KGDB: internal test suite" default n help This is a kgdb I/O module specifically designed to test kgdb's internal functions. This kgdb I/O module is intended to for the development of new kgdb stubs as well as regression testing the kgdb internals. See the drivers/misc/kgdbts.c for the details about the tests. The most basic of this I/O module is to boot a kernel boot arguments "kgdbwait kgdbts=V1F100" config KGDB_TESTS_ON_BOOT bool "KGDB: Run tests on boot" depends on KGDB_TESTS default n help Run the kgdb tests on boot up automatically without the need to pass in a kernel parameter config KGDB_TESTS_BOOT_STRING string "KGDB: which internal kgdb tests to run" depends on KGDB_TESTS_ON_BOOT default "V1F100" help This is the command string to send the kgdb test suite on boot. See the drivers/misc/kgdbts.c for detailed information about other strings you could use beyond the default of V1F100. config KGDB_LOW_LEVEL_TRAP bool "KGDB: Allow debugging with traps in notifiers" depends on X86 || MIPS default n help This will add an extra call back to kgdb for the breakpoint exception handler which will allow kgdb to step through a notify handler. config KGDB_KDB bool "KGDB_KDB: include kdb frontend for kgdb" default n help KDB frontend for kernel config KDB_DEFAULT_ENABLE hex "KDB: Select kdb command functions to be enabled by default" depends on KGDB_KDB default 0x1 help Specifiers which kdb commands are enabled by default. This may be set to 1 or 0 to enable all commands or disable almost all commands. Alternatively the following bitmask applies: 0x0002 - allow arbitrary reads from memory and symbol lookup 0x0004 - allow arbitrary writes to memory 0x0008 - allow current register state to be inspected 0x0010 - allow current register state to be modified 0x0020 - allow passive inspection (backtrace, process list, lsmod) 0x0040 - allow flow control management (breakpoint, single step) 0x0080 - enable signalling of processes 0x0100 - allow machine to be rebooted The config option merely sets the default at boot time. Both issuing 'echo X > /sys/module/kdb/parameters/cmd_enable' or setting with kdb.cmd_enable=X kernel command line option will override the default settings. config KDB_KEYBOARD bool "KGDB_KDB: keyboard as input device" depends on VT && KGDB_KDB default n help KDB can use a PS/2 type keyboard for an input device config KDB_CONTINUE_CATASTROPHIC int "KDB: continue after catastrophic errors" depends on KGDB_KDB default "0" help This integer controls the behaviour of kdb when the kernel gets a catastrophic error, i.e. for a panic or oops. When KDB is active and a catastrophic error occurs, nothing extra will happen until you type 'go'. CONFIG_KDB_CONTINUE_CATASTROPHIC == 0 (default). The first time you type 'go', you will be warned by kdb. The secend time you type 'go', KDB tries to continue. No guarantees that the kernel is still usable in this situation. CONFIG_KDB_CONTINUE_CATASTROPHIC == 1. KDB tries to continue. No guarantees that the kernel is still usable in this situation. CONFIG_KDB_CONTINUE_CATASTROPHIC == 2. KDB forces a reboot. If you are not sure, say 0. config ARCH_HAS_EARLY_DEBUG bool default n help If an architecture can definitely handle entering the debugger when early_param's are parsed then it select this config. Otherwise, if "kgdbwait" is passed on the kernel command line it won't actually be processed until dbg_late_init() just after the call to kgdb_arch_late() is made. NOTE: Even if this isn't selected by an architecture we will still try to register kgdb to handle breakpoints and crashes when early_param's are parsed, we just won't act on the "kgdbwait" parameter until dbg_late_init(). If you get a crash and try to drop into kgdb somewhere between these two places you might or might not end up being able to use kgdb depending on exactly how far along the architecture has initted. endif # KGDB