dd902d015a
properly nested and warns about recursive entrances. Unlike with locks, there is nothing fundamentally wrong with such use, the intent of tracer is to help to review complex epoch-protected code paths, and we mean the network stack here. Reviewed by: hselasky Sponsored by: Netflix Pull Request: https://reviews.freebsd.org/D21610
278 lines
6.2 KiB
C
278 lines
6.2 KiB
C
/*-
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* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
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*
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* Copyright (c) 2005 Antoine Brodin
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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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* 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 AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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#include "opt_ddb.h"
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#include <sys/cdefs.h>
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__FBSDID("$FreeBSD$");
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#include <sys/param.h>
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#include <sys/kernel.h>
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#ifdef KTR
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#include <sys/ktr.h>
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#endif
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#include <sys/linker.h>
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#include <sys/malloc.h>
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#include <sys/sbuf.h>
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#include <sys/stack.h>
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#include <sys/systm.h>
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#include <sys/sysctl.h>
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FEATURE(stack, "Support for capturing kernel stack");
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MALLOC_DEFINE(M_STACK, "stack", "Stack Traces");
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static int stack_symbol(vm_offset_t pc, char *namebuf, u_int buflen,
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long *offset, int flags);
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static int stack_symbol_ddb(vm_offset_t pc, const char **name, long *offset);
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struct stack *
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stack_create(int flags)
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{
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struct stack *st;
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st = malloc(sizeof(*st), M_STACK, flags | M_ZERO);
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return (st);
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}
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void
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stack_destroy(struct stack *st)
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{
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free(st, M_STACK);
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}
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int
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stack_put(struct stack *st, vm_offset_t pc)
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{
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if (st->depth < STACK_MAX) {
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st->pcs[st->depth++] = pc;
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return (0);
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} else
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return (-1);
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}
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void
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stack_copy(const struct stack *src, struct stack *dst)
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{
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*dst = *src;
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}
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void
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stack_zero(struct stack *st)
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{
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bzero(st, sizeof *st);
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}
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void
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stack_print(const struct stack *st)
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{
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char namebuf[64];
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long offset;
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int i;
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KASSERT(st->depth <= STACK_MAX, ("bogus stack"));
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for (i = 0; i < st->depth; i++) {
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(void)stack_symbol(st->pcs[i], namebuf, sizeof(namebuf),
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&offset, M_WAITOK);
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printf("#%d %p at %s+%#lx\n", i, (void *)st->pcs[i],
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namebuf, offset);
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}
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}
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void
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stack_print_short(const struct stack *st)
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{
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char namebuf[64];
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long offset;
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int i;
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KASSERT(st->depth <= STACK_MAX, ("bogus stack"));
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for (i = 0; i < st->depth; i++) {
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if (i > 0)
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printf(" ");
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if (stack_symbol(st->pcs[i], namebuf, sizeof(namebuf),
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&offset, M_WAITOK) == 0)
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printf("%s+%#lx", namebuf, offset);
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else
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printf("%p", (void *)st->pcs[i]);
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}
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printf("\n");
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}
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void
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stack_print_ddb(const struct stack *st)
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{
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const char *name;
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long offset;
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int i;
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KASSERT(st->depth <= STACK_MAX, ("bogus stack"));
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for (i = 0; i < st->depth; i++) {
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stack_symbol_ddb(st->pcs[i], &name, &offset);
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printf("#%d %p at %s+%#lx\n", i, (void *)st->pcs[i],
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name, offset);
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}
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}
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#if defined(DDB) || defined(WITNESS)
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void
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stack_print_short_ddb(const struct stack *st)
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{
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const char *name;
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long offset;
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int i;
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KASSERT(st->depth <= STACK_MAX, ("bogus stack"));
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for (i = 0; i < st->depth; i++) {
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if (i > 0)
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printf(" ");
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if (stack_symbol_ddb(st->pcs[i], &name, &offset) == 0)
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printf("%s+%#lx", name, offset);
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else
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printf("%p", (void *)st->pcs[i]);
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}
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printf("\n");
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}
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#endif
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/*
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* Format stack into sbuf from live kernel.
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*
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* flags - M_WAITOK or M_NOWAIT (EWOULDBLOCK).
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*/
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int
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stack_sbuf_print_flags(struct sbuf *sb, const struct stack *st, int flags)
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{
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char namebuf[64];
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long offset;
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int i, error;
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KASSERT(st->depth <= STACK_MAX, ("bogus stack"));
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for (i = 0; i < st->depth; i++) {
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error = stack_symbol(st->pcs[i], namebuf, sizeof(namebuf),
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&offset, flags);
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if (error == EWOULDBLOCK)
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return (error);
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sbuf_printf(sb, "#%d %p at %s+%#lx\n", i, (void *)st->pcs[i],
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namebuf, offset);
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}
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return (0);
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}
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void
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stack_sbuf_print(struct sbuf *sb, const struct stack *st)
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{
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(void)stack_sbuf_print_flags(sb, st, M_WAITOK);
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}
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#if defined(DDB) || defined(WITNESS)
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void
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stack_sbuf_print_ddb(struct sbuf *sb, const struct stack *st)
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{
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const char *name;
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long offset;
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int i;
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KASSERT(st->depth <= STACK_MAX, ("bogus stack"));
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for (i = 0; i < st->depth; i++) {
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(void)stack_symbol_ddb(st->pcs[i], &name, &offset);
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sbuf_printf(sb, "#%d %p at %s+%#lx\n", i, (void *)st->pcs[i],
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name, offset);
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}
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}
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#endif
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#ifdef KTR
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void
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stack_ktr(u_int mask, const char *file, int line, const struct stack *st,
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u_int depth)
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{
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#ifdef DDB
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const char *name;
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long offset;
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int i;
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#endif
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KASSERT(st->depth <= STACK_MAX, ("bogus stack"));
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#ifdef DDB
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if (depth == 0 || st->depth < depth)
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depth = st->depth;
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for (i = 0; i < depth; i++) {
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(void)stack_symbol_ddb(st->pcs[i], &name, &offset);
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ktr_tracepoint(mask, file, line, "#%d %p at %s+%#lx",
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i, st->pcs[i], (u_long)name, offset, 0, 0);
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}
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#endif
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}
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#endif
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/*
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* Two variants of stack symbol lookup -- one that uses the DDB interfaces
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* and bypasses linker locking, and the other that doesn't.
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*/
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static int
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stack_symbol(vm_offset_t pc, char *namebuf, u_int buflen, long *offset,
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int flags)
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{
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int error;
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error = linker_search_symbol_name_flags((caddr_t)pc, namebuf, buflen,
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offset, flags);
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if (error == 0 || error == EWOULDBLOCK)
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return (error);
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*offset = 0;
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strlcpy(namebuf, "??", buflen);
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return (ENOENT);
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}
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static int
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stack_symbol_ddb(vm_offset_t pc, const char **name, long *offset)
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{
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linker_symval_t symval;
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c_linker_sym_t sym;
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if (linker_ddb_search_symbol((caddr_t)pc, &sym, offset) != 0)
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goto out;
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if (linker_ddb_symbol_values(sym, &symval) != 0)
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goto out;
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if (symval.name != NULL) {
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*name = symval.name;
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return (0);
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}
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out:
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*offset = 0;
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*name = "??";
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return (ENOENT);
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}
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