1ec8f24b7SThomas Gleixner# SPDX-License-Identifier: GPL-2.0-only 2dc7d5527SJason Wessel 3e024cbd2SJan Engelhardtconfig HAVE_ARCH_KGDB 4e024cbd2SJan Engelhardt bool 5e024cbd2SJan Engelhardt 68c080d3aSVincent Chen# set if architecture has the its kgdb_arch_handle_qxfer_pkt 78c080d3aSVincent Chen# function to enable gdb stub to address XML packet sent from GDB. 88c080d3aSVincent Chenconfig HAVE_ARCH_KGDB_QXFER_PKT 98c080d3aSVincent Chen bool 108c080d3aSVincent Chen 11dc7d5527SJason Wesselmenuconfig KGDB 12dcc78711SJason Wessel bool "KGDB: kernel debugger" 13dc7d5527SJason Wessel depends on HAVE_ARCH_KGDB 14525c1f92SKees Cook depends on DEBUG_KERNEL 15dc7d5527SJason Wessel help 16dc7d5527SJason Wessel If you say Y here, it will be possible to remotely debug the 175f5ddfb3SJason Wessel kernel using gdb. It is recommended but not required, that 185f5ddfb3SJason Wessel you also turn on the kernel config option 195f5ddfb3SJason Wessel CONFIG_FRAME_POINTER to aid in producing more reliable stack 205f5ddfb3SJason Wessel backtraces in the external debugger. Documentation of 215f5ddfb3SJason Wessel kernel debugger is available at http://kgdb.sourceforge.net 2208c76a2fSMauro Carvalho Chehab as well as in Documentation/dev-tools/kgdb.rst. If 235f5ddfb3SJason Wessel unsure, say N. 24dc7d5527SJason Wessel 25e024cbd2SJan Engelhardtif KGDB 26dc7d5527SJason Wessel 27f2d10ff4SDaniel Thompsonconfig KGDB_HONOUR_BLOCKLIST 28f2d10ff4SDaniel Thompson bool "KGDB: use kprobe blocklist to prohibit unsafe breakpoints" 29f2d10ff4SDaniel Thompson depends on HAVE_KPROBES 30f2d10ff4SDaniel Thompson depends on MODULES 31f2d10ff4SDaniel Thompson select KPROBES 32f2d10ff4SDaniel Thompson default y 33f2d10ff4SDaniel Thompson help 34f2d10ff4SDaniel Thompson If set to Y the debug core will use the kprobe blocklist to 35f2d10ff4SDaniel Thompson identify symbols where it is unsafe to set breakpoints. 36f2d10ff4SDaniel Thompson In particular this disallows instrumentation of functions 37f2d10ff4SDaniel Thompson called during debug trap handling and thus makes it very 38f2d10ff4SDaniel Thompson difficult to inadvertently provoke recursive trap handling. 39f2d10ff4SDaniel Thompson 40f2d10ff4SDaniel Thompson If unsure, say Y. 41f2d10ff4SDaniel Thompson 42dc7d5527SJason Wesselconfig KGDB_SERIAL_CONSOLE 43dc7d5527SJason Wessel tristate "KGDB: use kgdb over the serial console" 44dc7d5527SJason Wessel select CONSOLE_POLL 45dc7d5527SJason Wessel select MAGIC_SYSRQ 465c49b6a4SLukas Bulwahn depends on TTY && VT 47dc7d5527SJason Wessel default y 48dc7d5527SJason Wessel help 49dc7d5527SJason Wessel Share a serial console with kgdb. Sysrq-g must be used 50dc7d5527SJason Wessel to break in initially. 51e8d31c20SJason Wessel 52e8d31c20SJason Wesselconfig KGDB_TESTS 53e8d31c20SJason Wessel bool "KGDB: internal test suite" 54e8d31c20SJason Wessel default n 55e8d31c20SJason Wessel help 56e8d31c20SJason Wessel This is a kgdb I/O module specifically designed to test 57e8d31c20SJason Wessel kgdb's internal functions. This kgdb I/O module is 58e8d31c20SJason Wessel intended to for the development of new kgdb stubs 59e8d31c20SJason Wessel as well as regression testing the kgdb internals. 60e8d31c20SJason Wessel See the drivers/misc/kgdbts.c for the details about 61e8d31c20SJason Wessel the tests. The most basic of this I/O module is to boot 62e8d31c20SJason Wessel a kernel boot arguments "kgdbwait kgdbts=V1F100" 63974460c5SJason Wessel 64974460c5SJason Wesselconfig KGDB_TESTS_ON_BOOT 65974460c5SJason Wessel bool "KGDB: Run tests on boot" 66974460c5SJason Wessel depends on KGDB_TESTS 67974460c5SJason Wessel default n 68974460c5SJason Wessel help 69974460c5SJason Wessel Run the kgdb tests on boot up automatically without the need 70974460c5SJason Wessel to pass in a kernel parameter 71974460c5SJason Wessel 72974460c5SJason Wesselconfig KGDB_TESTS_BOOT_STRING 73974460c5SJason Wessel string "KGDB: which internal kgdb tests to run" 74974460c5SJason Wessel depends on KGDB_TESTS_ON_BOOT 75974460c5SJason Wessel default "V1F100" 76974460c5SJason Wessel help 77974460c5SJason Wessel This is the command string to send the kgdb test suite on 78974460c5SJason Wessel boot. See the drivers/misc/kgdbts.c for detailed 79974460c5SJason Wessel information about other strings you could use beyond the 80974460c5SJason Wessel default of V1F100. 81e024cbd2SJan Engelhardt 82f503b5aeSJason Wesselconfig KGDB_LOW_LEVEL_TRAP 83f503b5aeSJason Wessel bool "KGDB: Allow debugging with traps in notifiers" 845dd11d5dSJason Wessel depends on X86 || MIPS 85f503b5aeSJason Wessel default n 86f503b5aeSJason Wessel help 87f503b5aeSJason Wessel This will add an extra call back to kgdb for the breakpoint 88278cee05SMasanari Iida exception handler which will allow kgdb to step through a 89278cee05SMasanari Iida notify handler. 90f503b5aeSJason Wessel 91dcc78711SJason Wesselconfig KGDB_KDB 92dcc78711SJason Wessel bool "KGDB_KDB: include kdb frontend for kgdb" 93dcc78711SJason Wessel default n 94dcc78711SJason Wessel help 95dcc78711SJason Wessel KDB frontend for kernel 96dcc78711SJason Wessel 97b8017177SDaniel Thompsonconfig KDB_DEFAULT_ENABLE 98b8017177SDaniel Thompson hex "KDB: Select kdb command functions to be enabled by default" 99b8017177SDaniel Thompson depends on KGDB_KDB 100b8017177SDaniel Thompson default 0x1 101b8017177SDaniel Thompson help 102b8017177SDaniel Thompson Specifiers which kdb commands are enabled by default. This may 103b8017177SDaniel Thompson be set to 1 or 0 to enable all commands or disable almost all 104b8017177SDaniel Thompson commands. 105b8017177SDaniel Thompson 106b8017177SDaniel Thompson Alternatively the following bitmask applies: 107b8017177SDaniel Thompson 108b8017177SDaniel Thompson 0x0002 - allow arbitrary reads from memory and symbol lookup 109b8017177SDaniel Thompson 0x0004 - allow arbitrary writes to memory 110b8017177SDaniel Thompson 0x0008 - allow current register state to be inspected 111b8017177SDaniel Thompson 0x0010 - allow current register state to be modified 112b8017177SDaniel Thompson 0x0020 - allow passive inspection (backtrace, process list, lsmod) 113b8017177SDaniel Thompson 0x0040 - allow flow control management (breakpoint, single step) 114b8017177SDaniel Thompson 0x0080 - enable signalling of processes 115b8017177SDaniel Thompson 0x0100 - allow machine to be rebooted 116b8017177SDaniel Thompson 117b8017177SDaniel Thompson The config option merely sets the default at boot time. Both 118b8017177SDaniel Thompson issuing 'echo X > /sys/module/kdb/parameters/cmd_enable' or 119b8017177SDaniel Thompson setting with kdb.cmd_enable=X kernel command line option will 120b8017177SDaniel Thompson override the default settings. 121b8017177SDaniel Thompson 122ada64e4cSJason Wesselconfig KDB_KEYBOARD 123ada64e4cSJason Wessel bool "KGDB_KDB: keyboard as input device" 124027c3d34SHelge Deller depends on VT && KGDB_KDB && !PARISC 125*b157f0e9SNiklas Schnelle depends on HAS_IOPORT 126ada64e4cSJason Wessel default n 127ada64e4cSJason Wessel help 128ada64e4cSJason Wessel KDB can use a PS/2 type keyboard for an input device 129ada64e4cSJason Wessel 1303b0eb71eSRobert Obermeierconfig KDB_CONTINUE_CATASTROPHIC 1313b0eb71eSRobert Obermeier int "KDB: continue after catastrophic errors" 1323b0eb71eSRobert Obermeier depends on KGDB_KDB 1333b0eb71eSRobert Obermeier default "0" 1343b0eb71eSRobert Obermeier help 1353b0eb71eSRobert Obermeier This integer controls the behaviour of kdb when the kernel gets a 1363b0eb71eSRobert Obermeier catastrophic error, i.e. for a panic or oops. 1373b0eb71eSRobert Obermeier When KDB is active and a catastrophic error occurs, nothing extra 1383b0eb71eSRobert Obermeier will happen until you type 'go'. 1393b0eb71eSRobert Obermeier CONFIG_KDB_CONTINUE_CATASTROPHIC == 0 (default). The first time 1403b0eb71eSRobert Obermeier you type 'go', you will be warned by kdb. The secend time you type 1413b0eb71eSRobert Obermeier 'go', KDB tries to continue. No guarantees that the 1423b0eb71eSRobert Obermeier kernel is still usable in this situation. 1433b0eb71eSRobert Obermeier CONFIG_KDB_CONTINUE_CATASTROPHIC == 1. KDB tries to continue. 1443b0eb71eSRobert Obermeier No guarantees that the kernel is still usable in this situation. 1453b0eb71eSRobert Obermeier CONFIG_KDB_CONTINUE_CATASTROPHIC == 2. KDB forces a reboot. 1463b0eb71eSRobert Obermeier If you are not sure, say 0. 1473b0eb71eSRobert Obermeier 148b1a57bbfSDouglas Andersonconfig ARCH_HAS_EARLY_DEBUG 149b1a57bbfSDouglas Anderson bool 150b1a57bbfSDouglas Anderson default n 151b1a57bbfSDouglas Anderson help 152b1a57bbfSDouglas Anderson If an architecture can definitely handle entering the debugger 153b1a57bbfSDouglas Anderson when early_param's are parsed then it select this config. 154b1a57bbfSDouglas Anderson Otherwise, if "kgdbwait" is passed on the kernel command line it 155b1a57bbfSDouglas Anderson won't actually be processed until dbg_late_init() just after the 156b1a57bbfSDouglas Anderson call to kgdb_arch_late() is made. 157b1a57bbfSDouglas Anderson 158b1a57bbfSDouglas Anderson NOTE: Even if this isn't selected by an architecture we will 159b1a57bbfSDouglas Anderson still try to register kgdb to handle breakpoints and crashes 160b1a57bbfSDouglas Anderson when early_param's are parsed, we just won't act on the 161b1a57bbfSDouglas Anderson "kgdbwait" parameter until dbg_late_init(). If you get a 162b1a57bbfSDouglas Anderson crash and try to drop into kgdb somewhere between these two 163b1a57bbfSDouglas Anderson places you might or might not end up being able to use kgdb 164b1a57bbfSDouglas Anderson depending on exactly how far along the architecture has initted. 165b1a57bbfSDouglas Anderson 166e024cbd2SJan Engelhardtendif # KGDB 167