3f14675cff
accessible:
(1) Always compile in support for breaking into the debugger if options
KDB is present in the kernel.
(2) Disable both by default, but allow them to be enabled via tunables
and sysctls debug.kdb.break_to_debugger and
debug.kdb.alt_break_to_debugger.
(3) options BREAK_TO_DEBUGGER and options ALT_BREAK_TO_DEBUGGER continue
to behave as before -- only now instead of compiling in
break-to-debugger support, they change the default values of the
above sysctls to enable those features by default. Current kernel
configurations should, therefore, continue to behave as expected.
(4) Migrate alternative break-to-debugger state machine logic out of
individual device drivers into centralised KDB code. This has a
number of upsides, but also one downside: it's now tricky to release
sio spin locks when entering the debugger, so we don't. However,
similar logic does not exist in other device drivers, including uart.
(5) dcons requires some special handling; unlike other console types, it
allows overriding KDB's own debugger selection, so we need a new
interface to KDB to allow that to work.
GENERIC kernels in -CURRENT will now support break-to-debugger as long as
appropriate boot/run-time options are set, which should improve the
debuggability of BETA kernels significantly.
MFC after: 3 weeks
Reviewed by: kib, nwhitehorn
Approved by: re (bz)
119 lines
4.5 KiB
C
119 lines
4.5 KiB
C
/*-
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* Copyright (c) 2004 Marcel Moolenaar
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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*
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*
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* $FreeBSD$
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*/
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#ifndef _SYS_KDB_H_
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#define _SYS_KDB_H_
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#include <machine/setjmp.h>
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typedef int dbbe_init_f(void);
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typedef void dbbe_trace_f(void);
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typedef int dbbe_trap_f(int, int);
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struct kdb_dbbe {
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const char *dbbe_name;
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dbbe_init_f *dbbe_init;
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dbbe_trace_f *dbbe_trace;
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dbbe_trap_f *dbbe_trap;
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int dbbe_active;
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};
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#define KDB_BACKEND(name, init, trace, trap) \
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static struct kdb_dbbe name##_dbbe = { \
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.dbbe_name = #name, \
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.dbbe_init = init, \
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.dbbe_trace = trace, \
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.dbbe_trap = trap \
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}; \
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DATA_SET(kdb_dbbe_set, name##_dbbe)
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struct pcb;
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struct thread;
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struct trapframe;
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extern int kdb_active; /* Non-zero while in debugger. */
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extern int debugger_on_panic; /* enter the debugger on panic. */
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extern struct kdb_dbbe *kdb_dbbe; /* Default debugger backend or NULL. */
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extern struct trapframe *kdb_frame; /* Frame to kdb_trap(). */
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extern struct pcb *kdb_thrctx; /* Current context. */
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extern struct thread *kdb_thread; /* Current thread. */
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int kdb_alt_break(int, int *);
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int kdb_alt_break_gdb(int, int *);
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int kdb_break(void);
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void kdb_backtrace(void);
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int kdb_dbbe_select(const char *);
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void kdb_enter(const char *, const char *);
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void kdb_init(void);
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void * kdb_jmpbuf(jmp_buf);
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void kdb_panic(const char *);
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void kdb_reboot(void);
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void kdb_reenter(void);
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struct pcb *kdb_thr_ctx(struct thread *);
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struct thread *kdb_thr_first(void);
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struct thread *kdb_thr_from_pid(pid_t);
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struct thread *kdb_thr_lookup(lwpid_t);
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struct thread *kdb_thr_next(struct thread *);
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int kdb_thr_select(struct thread *);
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int kdb_trap(int, int, struct trapframe *);
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/*
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* KDB enters the debugger via breakpoint(), which leaves the debugger without
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* a lot of information about why it was entered. This simple enumerated set
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* captures some basic information.
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*
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* It is recommended that values here be short (<16 character) alpha-numeric
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* strings, as they will be used to construct DDB(4) script names.
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*/
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extern const char * volatile kdb_why;
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#define KDB_WHY_UNSET NULL /* No reason set. */
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#define KDB_WHY_PANIC "panic" /* panic() was called. */
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#define KDB_WHY_SYSCTL "sysctl" /* Sysctl entered debugger. */
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#define KDB_WHY_BOOTFLAGS "bootflags" /* Boot flags were set. */
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#define KDB_WHY_WITNESS "witness" /* Witness entered debugger. */
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#define KDB_WHY_VFSLOCK "vfslock" /* VFS detected lock problem. */
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#define KDB_WHY_NETGRAPH "netgraph" /* Netgraph entered debugger. */
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#define KDB_WHY_BREAK "break" /* Console or serial break. */
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#define KDB_WHY_WATCHDOG "watchdog" /* Watchdog entered debugger. */
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#define KDB_WHY_CAM "cam" /* CAM has entered debugger. */
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#define KDB_WHY_NDIS "ndis" /* NDIS entered debugger. */
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#define KDB_WHY_ACPI "acpi" /* ACPI entered debugger. */
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#define KDB_WHY_TRAPSIG "trapsig" /* Sparc fault. */
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#define KDB_WHY_POWERFAIL "powerfail" /* Powerfail NMI. */
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#define KDB_WHY_MAC "mac" /* MAC Framework. */
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#define KDB_WHY_POWERPC "powerpc" /* Unhandled powerpc intr. */
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#define KDB_WHY_UNIONFS "unionfs" /* Unionfs bug. */
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#define KDB_WHY_DTRACE "dtrace" /* DTrace action entered debugger. */
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/* Return values for kdb_alt_break */
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#define KDB_REQ_DEBUGGER 1 /* User requested Debugger */
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#define KDB_REQ_PANIC 2 /* User requested a panic */
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#define KDB_REQ_REBOOT 3 /* User requested a clean reboot */
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#endif /* !_SYS_KDB_H_ */
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