1# SPDX-License-Identifier: GPL-2.0-only 2 3config HAVE_ARCH_KGDB 4 bool 5 6# set if architecture has the its kgdb_arch_handle_qxfer_pkt 7# function to enable gdb stub to address XML packet sent from GDB. 8config HAVE_ARCH_KGDB_QXFER_PKT 9 bool 10 11menuconfig KGDB 12 bool "KGDB: kernel debugger" 13 depends on HAVE_ARCH_KGDB 14 depends on DEBUG_KERNEL 15 help 16 If you say Y here, it will be possible to remotely debug the 17 kernel using gdb. It is recommended but not required, that 18 you also turn on the kernel config option 19 CONFIG_FRAME_POINTER to aid in producing more reliable stack 20 backtraces in the external debugger. Documentation of 21 kernel debugger is available at http://kgdb.sourceforge.net 22 as well as in Documentation/dev-tools/kgdb.rst. If 23 unsure, say N. 24 25if KGDB 26 27config KGDB_SERIAL_CONSOLE 28 tristate "KGDB: use kgdb over the serial console" 29 select CONSOLE_POLL 30 select MAGIC_SYSRQ 31 depends on TTY && HW_CONSOLE 32 default y 33 help 34 Share a serial console with kgdb. Sysrq-g must be used 35 to break in initially. 36 37config KGDB_TESTS 38 bool "KGDB: internal test suite" 39 default n 40 help 41 This is a kgdb I/O module specifically designed to test 42 kgdb's internal functions. This kgdb I/O module is 43 intended to for the development of new kgdb stubs 44 as well as regression testing the kgdb internals. 45 See the drivers/misc/kgdbts.c for the details about 46 the tests. The most basic of this I/O module is to boot 47 a kernel boot arguments "kgdbwait kgdbts=V1F100" 48 49config KGDB_TESTS_ON_BOOT 50 bool "KGDB: Run tests on boot" 51 depends on KGDB_TESTS 52 default n 53 help 54 Run the kgdb tests on boot up automatically without the need 55 to pass in a kernel parameter 56 57config KGDB_TESTS_BOOT_STRING 58 string "KGDB: which internal kgdb tests to run" 59 depends on KGDB_TESTS_ON_BOOT 60 default "V1F100" 61 help 62 This is the command string to send the kgdb test suite on 63 boot. See the drivers/misc/kgdbts.c for detailed 64 information about other strings you could use beyond the 65 default of V1F100. 66 67config KGDB_LOW_LEVEL_TRAP 68 bool "KGDB: Allow debugging with traps in notifiers" 69 depends on X86 || MIPS 70 default n 71 help 72 This will add an extra call back to kgdb for the breakpoint 73 exception handler which will allow kgdb to step through a 74 notify handler. 75 76config KGDB_KDB 77 bool "KGDB_KDB: include kdb frontend for kgdb" 78 default n 79 help 80 KDB frontend for kernel 81 82config KDB_DEFAULT_ENABLE 83 hex "KDB: Select kdb command functions to be enabled by default" 84 depends on KGDB_KDB 85 default 0x1 86 help 87 Specifiers which kdb commands are enabled by default. This may 88 be set to 1 or 0 to enable all commands or disable almost all 89 commands. 90 91 Alternatively the following bitmask applies: 92 93 0x0002 - allow arbitrary reads from memory and symbol lookup 94 0x0004 - allow arbitrary writes to memory 95 0x0008 - allow current register state to be inspected 96 0x0010 - allow current register state to be modified 97 0x0020 - allow passive inspection (backtrace, process list, lsmod) 98 0x0040 - allow flow control management (breakpoint, single step) 99 0x0080 - enable signalling of processes 100 0x0100 - allow machine to be rebooted 101 102 The config option merely sets the default at boot time. Both 103 issuing 'echo X > /sys/module/kdb/parameters/cmd_enable' or 104 setting with kdb.cmd_enable=X kernel command line option will 105 override the default settings. 106 107config KDB_KEYBOARD 108 bool "KGDB_KDB: keyboard as input device" 109 depends on VT && KGDB_KDB 110 default n 111 help 112 KDB can use a PS/2 type keyboard for an input device 113 114config KDB_CONTINUE_CATASTROPHIC 115 int "KDB: continue after catastrophic errors" 116 depends on KGDB_KDB 117 default "0" 118 help 119 This integer controls the behaviour of kdb when the kernel gets a 120 catastrophic error, i.e. for a panic or oops. 121 When KDB is active and a catastrophic error occurs, nothing extra 122 will happen until you type 'go'. 123 CONFIG_KDB_CONTINUE_CATASTROPHIC == 0 (default). The first time 124 you type 'go', you will be warned by kdb. The secend time you type 125 'go', KDB tries to continue. No guarantees that the 126 kernel is still usable in this situation. 127 CONFIG_KDB_CONTINUE_CATASTROPHIC == 1. KDB tries to continue. 128 No guarantees that the kernel is still usable in this situation. 129 CONFIG_KDB_CONTINUE_CATASTROPHIC == 2. KDB forces a reboot. 130 If you are not sure, say 0. 131 132config ARCH_HAS_EARLY_DEBUG 133 bool 134 default n 135 help 136 If an architecture can definitely handle entering the debugger 137 when early_param's are parsed then it select this config. 138 Otherwise, if "kgdbwait" is passed on the kernel command line it 139 won't actually be processed until dbg_late_init() just after the 140 call to kgdb_arch_late() is made. 141 142 NOTE: Even if this isn't selected by an architecture we will 143 still try to register kgdb to handle breakpoints and crashes 144 when early_param's are parsed, we just won't act on the 145 "kgdbwait" parameter until dbg_late_init(). If you get a 146 crash and try to drop into kgdb somewhere between these two 147 places you might or might not end up being able to use kgdb 148 depending on exactly how far along the architecture has initted. 149 150endif # KGDB 151