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_HONOUR_BLOCKLIST 28 bool "KGDB: use kprobe blocklist to prohibit unsafe breakpoints" 29 depends on HAVE_KPROBES 30 depends on MODULES 31 select KPROBES 32 default y 33 help 34 If set to Y the debug core will use the kprobe blocklist to 35 identify symbols where it is unsafe to set breakpoints. 36 In particular this disallows instrumentation of functions 37 called during debug trap handling and thus makes it very 38 difficult to inadvertently provoke recursive trap handling. 39 40 If unsure, say Y. 41 42config KGDB_SERIAL_CONSOLE 43 tristate "KGDB: use kgdb over the serial console" 44 select CONSOLE_POLL 45 select MAGIC_SYSRQ 46 depends on TTY && VT 47 default y 48 help 49 Share a serial console with kgdb. Sysrq-g must be used 50 to break in initially. 51 52config KGDB_TESTS 53 bool "KGDB: internal test suite" 54 default n 55 help 56 This is a kgdb I/O module specifically designed to test 57 kgdb's internal functions. This kgdb I/O module is 58 intended to for the development of new kgdb stubs 59 as well as regression testing the kgdb internals. 60 See the drivers/misc/kgdbts.c for the details about 61 the tests. The most basic of this I/O module is to boot 62 a kernel boot arguments "kgdbwait kgdbts=V1F100" 63 64config KGDB_TESTS_ON_BOOT 65 bool "KGDB: Run tests on boot" 66 depends on KGDB_TESTS 67 default n 68 help 69 Run the kgdb tests on boot up automatically without the need 70 to pass in a kernel parameter 71 72config KGDB_TESTS_BOOT_STRING 73 string "KGDB: which internal kgdb tests to run" 74 depends on KGDB_TESTS_ON_BOOT 75 default "V1F100" 76 help 77 This is the command string to send the kgdb test suite on 78 boot. See the drivers/misc/kgdbts.c for detailed 79 information about other strings you could use beyond the 80 default of V1F100. 81 82config KGDB_LOW_LEVEL_TRAP 83 bool "KGDB: Allow debugging with traps in notifiers" 84 depends on X86 || MIPS 85 default n 86 help 87 This will add an extra call back to kgdb for the breakpoint 88 exception handler which will allow kgdb to step through a 89 notify handler. 90 91config KGDB_KDB 92 bool "KGDB_KDB: include kdb frontend for kgdb" 93 default n 94 help 95 KDB frontend for kernel 96 97config KDB_DEFAULT_ENABLE 98 hex "KDB: Select kdb command functions to be enabled by default" 99 depends on KGDB_KDB 100 default 0x1 101 help 102 Specifiers which kdb commands are enabled by default. This may 103 be set to 1 or 0 to enable all commands or disable almost all 104 commands. 105 106 Alternatively the following bitmask applies: 107 108 0x0002 - allow arbitrary reads from memory and symbol lookup 109 0x0004 - allow arbitrary writes to memory 110 0x0008 - allow current register state to be inspected 111 0x0010 - allow current register state to be modified 112 0x0020 - allow passive inspection (backtrace, process list, lsmod) 113 0x0040 - allow flow control management (breakpoint, single step) 114 0x0080 - enable signalling of processes 115 0x0100 - allow machine to be rebooted 116 117 The config option merely sets the default at boot time. Both 118 issuing 'echo X > /sys/module/kdb/parameters/cmd_enable' or 119 setting with kdb.cmd_enable=X kernel command line option will 120 override the default settings. 121 122config KDB_KEYBOARD 123 bool "KGDB_KDB: keyboard as input device" 124 depends on VT && KGDB_KDB && !PARISC 125 default n 126 help 127 KDB can use a PS/2 type keyboard for an input device 128 129config KDB_CONTINUE_CATASTROPHIC 130 int "KDB: continue after catastrophic errors" 131 depends on KGDB_KDB 132 default "0" 133 help 134 This integer controls the behaviour of kdb when the kernel gets a 135 catastrophic error, i.e. for a panic or oops. 136 When KDB is active and a catastrophic error occurs, nothing extra 137 will happen until you type 'go'. 138 CONFIG_KDB_CONTINUE_CATASTROPHIC == 0 (default). The first time 139 you type 'go', you will be warned by kdb. The secend time you type 140 'go', KDB tries to continue. No guarantees that the 141 kernel is still usable in this situation. 142 CONFIG_KDB_CONTINUE_CATASTROPHIC == 1. KDB tries to continue. 143 No guarantees that the kernel is still usable in this situation. 144 CONFIG_KDB_CONTINUE_CATASTROPHIC == 2. KDB forces a reboot. 145 If you are not sure, say 0. 146 147config ARCH_HAS_EARLY_DEBUG 148 bool 149 default n 150 help 151 If an architecture can definitely handle entering the debugger 152 when early_param's are parsed then it select this config. 153 Otherwise, if "kgdbwait" is passed on the kernel command line it 154 won't actually be processed until dbg_late_init() just after the 155 call to kgdb_arch_late() is made. 156 157 NOTE: Even if this isn't selected by an architecture we will 158 still try to register kgdb to handle breakpoints and crashes 159 when early_param's are parsed, we just won't act on the 160 "kgdbwait" parameter until dbg_late_init(). If you get a 161 crash and try to drop into kgdb somewhere between these two 162 places you might or might not end up being able to use kgdb 163 depending on exactly how far along the architecture has initted. 164 165endif # KGDB 166