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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 && HW_CONSOLE
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
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
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 depends on HAS_IOPORT
126 default n
127 help
128 KDB can use a PS/2 type keyboard for an input device
129
130config KDB_CONTINUE_CATASTROPHIC
131 int "KDB: continue after catastrophic errors"
132 depends on KGDB_KDB
133 default "0"
134 help
135 This integer controls the behaviour of kdb when the kernel gets a
136 catastrophic error, i.e. for a panic or oops.
137 When KDB is active and a catastrophic error occurs, nothing extra
138 will happen until you type 'go'.
139 CONFIG_KDB_CONTINUE_CATASTROPHIC == 0 (default). The first time
140 you type 'go', you will be warned by kdb. The secend time you type
141 'go', KDB tries to continue. No guarantees that the
142 kernel is still usable in this situation.
143 CONFIG_KDB_CONTINUE_CATASTROPHIC == 1. KDB tries to continue.
144 No guarantees that the kernel is still usable in this situation.
145 CONFIG_KDB_CONTINUE_CATASTROPHIC == 2. KDB forces a reboot.
146 If you are not sure, say 0.
147
148config ARCH_HAS_EARLY_DEBUG
149 bool
150 default n
151 help
152 If an architecture can definitely handle entering the debugger
153 when early_param's are parsed then it select this config.
154 Otherwise, if "kgdbwait" is passed on the kernel command line it
155 won't actually be processed until dbg_late_init() just after the
156 call to kgdb_arch_late() is made.
157
158 NOTE: Even if this isn't selected by an architecture we will
159 still try to register kgdb to handle breakpoints and crashes
160 when early_param's are parsed, we just won't act on the
161 "kgdbwait" parameter until dbg_late_init(). If you get a
162 crash and try to drop into kgdb somewhere between these two
163 places you might or might not end up being able to use kgdb
164 depending on exactly how far along the architecture has initted.
165
166endif # KGDB