/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 2005 Antoine Brodin
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include "opt_ddb.h"
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/kernel.h>
#ifdef KTR
#include <sys/ktr.h>
#endif
#include <sys/linker.h>
#include <sys/malloc.h>
#include <sys/sbuf.h>
#include <sys/stack.h>
#include <sys/systm.h>
#include <sys/sysctl.h>
FEATURE(stack, "Support for capturing kernel stack");
MALLOC_DEFINE(M_STACK, "stack", "Stack Traces");
static int stack_symbol(vm_offset_t pc, char *namebuf, u_int buflen,
long *offset, int flags);
static int stack_symbol_ddb(vm_offset_t pc, const char **name, long *offset);
struct stack *
stack_create(int flags)
{
struct stack *st;
st = malloc(sizeof(*st), M_STACK, flags | M_ZERO);
return (st);
}
void
stack_destroy(struct stack *st)
{
free(st, M_STACK);
}
int
stack_put(struct stack *st, vm_offset_t pc)
{
if (st->depth < STACK_MAX) {
st->pcs[st->depth++] = pc;
return (0);
} else
return (-1);
}
void
stack_copy(const struct stack *src, struct stack *dst)
{
*dst = *src;
}
void
stack_zero(struct stack *st)
{
bzero(st, sizeof *st);
}
void
stack_print(const struct stack *st)
{
char namebuf[64];
long offset;
int i;
KASSERT(st->depth <= STACK_MAX, ("bogus stack"));
for (i = 0; i < st->depth; i++) {
(void)stack_symbol(st->pcs[i], namebuf, sizeof(namebuf),
&offset, M_WAITOK);
printf("#%d %p at %s+%#lx\n", i, (void *)st->pcs[i],
namebuf, offset);
}
}
void
stack_print_short(const struct stack *st)
{
char namebuf[64];
long offset;
int i;
KASSERT(st->depth <= STACK_MAX, ("bogus stack"));
for (i = 0; i < st->depth; i++) {
if (i > 0)
printf(" ");
if (stack_symbol(st->pcs[i], namebuf, sizeof(namebuf),
&offset, M_WAITOK) == 0)
printf("%s+%#lx", namebuf, offset);
else
printf("%p", (void *)st->pcs[i]);
}
printf("\n");
}
void
stack_print_ddb(const struct stack *st)
{
const char *name;
long offset;
int i;
KASSERT(st->depth <= STACK_MAX, ("bogus stack"));
for (i = 0; i < st->depth; i++) {
stack_symbol_ddb(st->pcs[i], &name, &offset);
printf("#%d %p at %s+%#lx\n", i, (void *)st->pcs[i],
name, offset);
}
}
#if defined(DDB) || defined(WITNESS)
void
stack_print_short_ddb(const struct stack *st)
{
const char *name;
long offset;
int i;
KASSERT(st->depth <= STACK_MAX, ("bogus stack"));
for (i = 0; i < st->depth; i++) {
if (i > 0)
printf(" ");
if (stack_symbol_ddb(st->pcs[i], &name, &offset) == 0)
printf("%s+%#lx", name, offset);
else
printf("%p", (void *)st->pcs[i]);
}
printf("\n");
}
#endif
/*
* Format stack into sbuf from live kernel.
*
* flags - M_WAITOK or M_NOWAIT (EWOULDBLOCK).
*/
int
stack_sbuf_print_flags(struct sbuf *sb, const struct stack *st, int flags,
enum stack_sbuf_fmt format)
{
char namebuf[64];
long offset;
int i, error;
KASSERT(st->depth <= STACK_MAX, ("bogus stack"));
for (i = 0; i < st->depth; i++) {
error = stack_symbol(st->pcs[i], namebuf, sizeof(namebuf),
&offset, flags);
if (error == EWOULDBLOCK)
return (error);
switch (format) {
case STACK_SBUF_FMT_LONG:
sbuf_printf(sb, "#%d %p at %s+%#lx\n", i,
(void *)st->pcs[i], namebuf, offset);
break;
case STACK_SBUF_FMT_COMPACT:
sbuf_printf(sb, "%s+%#lx ", namebuf, offset);
break;
default:
__assert_unreachable();
}
}
sbuf_nl_terminate(sb);
return (0);
}
void
stack_sbuf_print(struct sbuf *sb, const struct stack *st)
{
(void)stack_sbuf_print_flags(sb, st, M_WAITOK, STACK_SBUF_FMT_LONG);
}
#if defined(DDB) || defined(WITNESS)
void
stack_sbuf_print_ddb(struct sbuf *sb, const struct stack *st)
{
const char *name;
long offset;
int i;
KASSERT(st->depth <= STACK_MAX, ("bogus stack"));
for (i = 0; i < st->depth; i++) {
(void)stack_symbol_ddb(st->pcs[i], &name, &offset);
sbuf_printf(sb, "#%d %p at %s+%#lx\n", i, (void *)st->pcs[i],
name, offset);
}
}
#endif
#ifdef KTR
void
stack_ktr(u_int mask, const char *file, int line, const struct stack *st,
u_int depth)
{
#ifdef DDB
const char *name;
long offset;
int i;
#endif
KASSERT(st->depth <= STACK_MAX, ("bogus stack"));
#ifdef DDB
if (depth == 0 || st->depth < depth)
depth = st->depth;
for (i = 0; i < depth; i++) {
(void)stack_symbol_ddb(st->pcs[i], &name, &offset);
ktr_tracepoint(mask, file, line, "#%d %p at %s+%#lx",
i, st->pcs[i], (u_long)name, offset, 0, 0);
}
#endif
}
#endif
/*
* Two variants of stack symbol lookup -- one that uses the DDB interfaces
* and bypasses linker locking, and the other that doesn't.
*/
static int
stack_symbol(vm_offset_t pc, char *namebuf, u_int buflen, long *offset,
int flags)
{
int error;
error = linker_search_symbol_name_flags((caddr_t)pc, namebuf, buflen,
offset, flags);
if (error == 0 || error == EWOULDBLOCK)
return (error);
*offset = 0;
strlcpy(namebuf, "??", buflen);
return (ENOENT);
}
static int
stack_symbol_ddb(vm_offset_t pc, const char **name, long *offset)
{
linker_symval_t symval;
c_linker_sym_t sym;
if (linker_ddb_search_symbol((caddr_t)pc, &sym, offset) != 0)
goto out;
if (linker_ddb_symbol_values(sym, &symval) != 0)
goto out;
if (symval.name != NULL) {
*name = symval.name;
return (0);
}
out:
*offset = 0;
*name = "??";
return (ENOENT);
}
