freebsd-nq/sys/kern/subr_stack.c
Konstantin Belousov ea797aaed5 Ktr(9) stores format string and arguments in the event circular buffer,
not the string formatted at the time of CTRX() call. Stack_ktr(9) uses
an on-stack buffer for the symbol name, that is supplied as an argument
to ktr. As result, stack_ktr() traces show garbage or cause page faults.

Fix stack_ktr() by using pointer to module symbol table that is supposed
to have a longer lifetime.

Tested by:	pho
MFC after:	1 week
2008-10-19 11:13:49 +00:00

231 lines
5.4 KiB
C

/*-
* 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>
static MALLOC_DEFINE(M_STACK, "stack", "Stack Traces");
static void stack_symbol(vm_offset_t pc, char *namebuf, u_int buflen,
long *offset);
#ifdef DDB
static void stack_symbol_ddb(vm_offset_t pc, const char **name, long *offset);
#endif
struct stack *
stack_create(void)
{
struct stack *st;
st = malloc(sizeof *st, M_STACK, M_WAITOK | 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(struct stack *src, struct stack *dst)
{
*dst = *src;
}
void
stack_zero(struct stack *st)
{
bzero(st, sizeof *st);
}
void
stack_print(struct stack *st)
{
char namebuf[64];
long offset;
int i;
KASSERT(st->depth <= STACK_MAX, ("bogus stack"));
for (i = 0; i < st->depth; i++) {
stack_symbol(st->pcs[i], namebuf, sizeof(namebuf), &offset);
printf("#%d %p at %s+%#lx\n", i, (void *)st->pcs[i],
namebuf, offset);
}
}
#ifdef DDB
void
stack_print_ddb(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);
}
}
#endif
/*
* Two print routines -- one for use from DDB and DDB-like contexts, the
* other for use in the live kernel.
*/
void
stack_sbuf_print(struct sbuf *sb, struct stack *st)
{
char namebuf[64];
long offset;
int i;
KASSERT(st->depth <= STACK_MAX, ("bogus stack"));
for (i = 0; i < st->depth; i++) {
stack_symbol(st->pcs[i], namebuf, sizeof(namebuf), &offset);
sbuf_printf(sb, "#%d %p at %s+%#lx\n", i, (void *)st->pcs[i],
namebuf, offset);
}
}
#ifdef DDB
void
stack_sbuf_print_ddb(struct sbuf *sb, 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);
sbuf_printf(sb, "#%d %p at %s+%#lx\n", i, (void *)st->pcs[i],
name, offset);
}
}
#ifdef KTR
void
stack_ktr(u_int mask, const char *file, int line, struct stack *st, u_int depth,
int cheap)
{
const char *name;
long offset;
int i;
KASSERT(st->depth <= STACK_MAX, ("bogus stack"));
if (cheap) {
ktr_tracepoint(mask, file, line, "#0 %p %p %p %p %p %p",
st->pcs[0], st->pcs[1], st->pcs[2], st->pcs[3],
st->pcs[4], st->pcs[5]);
if (st->depth <= 6)
return;
ktr_tracepoint(mask, file, line, "#1 %p %p %p %p %p %p",
st->pcs[6], st->pcs[7], st->pcs[8], st->pcs[9],
st->pcs[10], st->pcs[11]);
if (st->depth <= 12)
return;
ktr_tracepoint(mask, file, line, "#2 %p %p %p %p %p %p",
st->pcs[12], st->pcs[13], st->pcs[14], st->pcs[15],
st->pcs[16], st->pcs[17]);
} else {
if (depth == 0 || st->depth < depth)
depth = st->depth;
for (i = 0; i < depth; i++) {
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 void
stack_symbol(vm_offset_t pc, char *namebuf, u_int buflen, long *offset)
{
if (linker_search_symbol_name((caddr_t)pc, namebuf, buflen,
offset) != 0) {
*offset = 0;
strlcpy(namebuf, "??", buflen);
}
}
#ifdef DDB
static void
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;
}
out:
*offset = 0;
*name = "??";
}
#endif