Add a similar to linux backtrace_* and execinfo.h family of functions

This commit is contained in:
christos 2012-05-26 22:02:29 +00:00
parent d9a1056489
commit 83d64dcffd
10 changed files with 906 additions and 0 deletions

31
lib/libexecinfo/Makefile Normal file
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# $NetBSD: Makefile,v 1.1 2012/05/26 22:02:29 christos Exp $
.include <bsd.own.mk>
USE_UNWIND=yes
WARNS?=4
INCSDIR=/usr/include
INCS=execinfo.h
#CPPFLAGS+='-D__RCSID(a)=' -D_GNU_SOURCE '-D__printflike(a,b)='
#CPPFLAGS+=-I/usr/include/libelf
#COPTS+=-std=gnu99
LIBDPLIBS+= elf ${NETBSDSRCDIR}/external/bsd/libelf/lib
LIB=execinfo
SRCS=symtab.c backtrace.c
MAN= backtrace.3
.if ${USE_UNWIND} == "yes"
SRCS+=unwind.c
.else
SRCS+=builtin.c
.endif
MLINKS+= backtrace.3 backtrace_symbols.3
MLINKS+= backtrace.3 backtrace_symbols_fmt.3
MLINKS+= backtrace.3 backtrace_symbols_fd.3
MLINKS+= backtrace.3 backtrace_symbols_fd_fmt.3
.include <bsd.lib.mk>

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lib/libexecinfo/backtrace.3 Normal file
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.\" $NetBSD: backtrace.3,v 1.1 2012/05/26 22:02:29 christos Exp $
.\"
.\" Copyright (c) 2012 The NetBSD Foundation, Inc.
.\" All rights reserved.
.\"
.\" This code is derived from software contributed to The NetBSD Foundation
.\" by Christos Zoulas
.\"
.\" 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
.\"
.Dd January 24, 2012
.Dt BACKTRACE 3
.Os
.Sh NAME
.Nm backtrace
.Nd fill in the backtrace of the currently executing thread.
.Sh LIBRARY
.Lb libexecinfo
.Sh SYNOPSIS
.In execinfo.h
.Ft size_t
.Fn backtrace "void **addrlist" "size_t len"
.Ft "char **"
.Fn backtrace_symbols "void * const *addrlist" "size_t len"
.Ft int
.Fn backtrace_symbols_fd "void * const *addrlist" "size_t len" "int fd"
.Ft "char **"
.Fn backtrace_symbols_fmt "void * const *addrlist" "size_t len" "const char *fmt"
.Ft int
.Fn backtrace_symbols_fmt_fd "void * const *addrlist" "size_t len" "const char *fmt" "int fd"
.Sh DESCRIPTION
The
.Fn backtrace
function places into the array pointed by
.Fa addrlist
the array of the values of the program counter for each frame called up to
.Fa len
frames.
The number of frames found (which can be fewer than
.Fa len )
is returned.
.Pp
The
.Fn backtrace_symbols_fmt
function, takes an array of previously filled addresses from
.Fn backtrace
in
.Fa addrlist
of
.Fa len
elements, and uses
.Fa fmt
to format them.
The formatting characters available are:
.Bl -tag -width a -offset indent
.It Dv a
The numeric address of each element as would be printed using %p.
.It Dv n
The name of the nearest function symbol (smaller than the address element)
as determined by
.Xr dladdr 3
if the symbol was dynamic, or looked up in the executable if static and
the /proc filesystem is available to determine the executable path.
.It Dv d
The difference of the symbol address and the address element printed
using 0x%tx.
.It Dv D
The difference of the symbol addresss and the address element printed using
+0x%tx if non-zero, or nothing if zero.
.It Dv f
The filename of the symbol as determined by
.Xr dladdr 3 .
.El
.Pp
The array of formatted strings is returned as a contiguous memory address which
can be freed by a single
.Xr free 3 .
.Pp
The
.Fn backtrace_symbols
function is equivalent of calling
.Fn backtrace_symbols_fmt
with a format argument of
.Dv "%a <%n%D> at %f"
.Pp
The
.Fn backtrace_symbols_fd
and
.Fn backtrace_symbols_fmt_fd
are similar to the non _fd named functions, only instead of returning
an array or strings, they print a new-line separated array of strings in
fd, and return
.Dv 0
on success and
.Dv \-1
on failure.
.Sh RETURN VALUES
The
.Fn backtrace
function returns the number of elements tht were filled in the backtrace.
The
.Fn backtrace_symbols
and
.Fn backtrace_symbols_fmt
return a string array on success, and
.Dv NULL
on failure, setting
.Va errno .
.\" XXX
Diagnostic output may also be produced, by the ELF symbol lookup functions.
function returns a pointer to a string that is the parent directory of
.Sh BUGS
.Bl -enum
.It
Errors should not be printed but communicated to the caller differently.
.It
Because these functions use
.Xr elf 3
this is a separate library instead of be part of libc/libutil so that library
dependencies are not introduced.
.It
The linux versions of the functions (there are no _fmt variants), use
.Ft int
instead of
.Ft size_t
arguments.
.It
Since
.Xr dladdr 3
only deals with dynamic symbols, we need to find the symbols from the main
portion of the program.
For that we need to locate the executable, and we use procfs for to find it
which is not portable.
.El
.Sh SEE ALSO
.Xr elf 3
.Xr dladdr 3
.Sh HISTORY
The
.Fn backtrace
library of functions first appeared in
.Nx 6 .

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lib/libexecinfo/backtrace.c Normal file
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/* $NetBSD: backtrace.c,v 1.1 2012/05/26 22:02:29 christos Exp $ */
/*-
* Copyright (c) 2012 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Christos Zoulas.
*
* 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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 <sys/cdefs.h>
__RCSID("$NetBSD: backtrace.c,v 1.1 2012/05/26 22:02:29 christos Exp $");
#include <sys/param.h>
#include <assert.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <stdarg.h>
#include <stdint.h>
#include <stddef.h>
#include <unistd.h>
#include <fcntl.h>
#include <dlfcn.h>
#include <elf.h>
#include "execinfo.h"
#include "symtab.h"
#ifdef __linux__
#define SELF "/proc/self/exe"
#else
#define SELF "/proc/curproc/file"
#endif
static int __printflike(4, 5)
rasprintf(char **buf, size_t *bufsiz, size_t offs, const char *fmt, ...)
{
for (;;) {
size_t nbufsiz;
char *nbuf;
if (*buf && offs < *bufsiz) {
va_list ap;
int len;
va_start(ap, fmt);
len = vsnprintf(*buf + offs, *bufsiz - offs, fmt, ap);
va_end(ap);
if (len < 0 || (size_t)len < *bufsiz - offs)
return len;
nbufsiz = MAX(*bufsiz + 512, (size_t)len + 1);
} else
nbufsiz = MAX(offs, *bufsiz) + 512;
nbuf = realloc(*buf, nbufsiz);
if (nbuf == NULL)
return -1;
*buf = nbuf;
*bufsiz = nbufsiz;
}
}
/*
* format specifiers:
* %a = address
* %n = symbol_name
* %d = symbol_address - address
* %D = if symbol_address == address "" else +%d
* %f = filename
*/
static ssize_t
format_string(char **buf, size_t *bufsiz, size_t offs, const char *fmt,
Dl_info *dli, const void *addr)
{
ptrdiff_t diff = (const char *)addr - (const char *)dli->dli_saddr;
size_t o = offs;
int len;
for (; *fmt; fmt++) {
if (*fmt != '%')
goto printone;
switch (*++fmt) {
case 'a':
len = rasprintf(buf, bufsiz, o, "%p", addr);
break;
case 'n':
len = rasprintf(buf, bufsiz, o, "%s", dli->dli_sname);
break;
case 'D':
if (diff)
len = rasprintf(buf, bufsiz, o, "+0x%tx", diff);
else
len = 0;
break;
case 'd':
len = rasprintf(buf, bufsiz, o, "0x%tx", diff);
break;
case 'f':
len = rasprintf(buf, bufsiz, o, "%s", dli->dli_fname);
break;
default:
printone:
len = rasprintf(buf, bufsiz, o, "%c", *fmt);
break;
}
if (len == -1)
return -1;
o += len;
}
return o - offs;
}
static ssize_t
format_address(symtab_t *st, char **buf, size_t *bufsiz, size_t offs,
const char *fmt, const void *addr)
{
Dl_info dli;
memset(&dli, 0, sizeof(dli));
(void)dladdr(addr, &dli);
if (st)
symtab_find(st, addr, &dli);
if (dli.dli_sname == NULL)
dli.dli_sname = "???";
if (dli.dli_fname == NULL)
dli.dli_fname = "???";
if (dli.dli_saddr == NULL)
dli.dli_saddr = (void *)(intptr_t)addr;
return format_string(buf, bufsiz, offs, fmt, &dli, addr);
}
char **
backtrace_symbols_fmt(void *const *trace, size_t len, const char *fmt)
{
static const size_t slen = sizeof(char *) + 64; /* estimate */
char *ptr;
symtab_t *st;
int fd;
if ((fd = open(SELF, O_RDONLY)) != -1)
st = symtab_create(fd, -1, STT_FUNC);
else
st = NULL;
if ((ptr = calloc(len, slen)) == NULL)
return NULL;
size_t psize = len * slen;
size_t offs = len * sizeof(char *);
/* We store only offsets in the first pass because of realloc */
for (size_t i = 0; i < len; i++) {
ssize_t x;
((char **)(void *)ptr)[i] = (void *)offs;
x = format_address(st, &ptr, &psize, offs, fmt, trace[i]);
if (x == -1) {
free(ptr);
return NULL;
}
offs += x;
ptr[offs++] = '\0';
assert(offs < psize);
}
/* Change offsets to pointers */
for (size_t j = 0; j < len; j++)
((char **)(void *)ptr)[j] += (intptr_t)ptr;
symtab_destroy(st);
if (fd != -1)
(void)close(fd);
return (void *)ptr;
}
int
backtrace_symbols_fd_fmt(void *const *trace, size_t len, int fd,
const char *fmt)
{
char **s = backtrace_symbols_fmt(trace, len, fmt);
if (s == NULL)
return -1;
for (size_t i = 0; i < len; i++)
if (dprintf(fd, "%s\n", s[i]) < 0)
break;
free(s);
return 0;
}
static const char fmt[] = "%a <%n%D> at %f";
char **
backtrace_symbols(void *const *trace, size_t len)
{
return backtrace_symbols_fmt(trace, len, fmt);
}
int
backtrace_symbols_fd(void *const *trace, size_t len, int fd)
{
return backtrace_symbols_fd_fmt(trace, len, fd, fmt);
}

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lib/libexecinfo/builtin.c Normal file
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/* $NetBSD: builtin.c,v 1.1 2012/05/26 22:02:29 christos Exp $ */
/*-
* Copyright (c) 2012 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Christos Zoulas.
*
* 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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 <sys/cdefs.h>
__RCSID("$NetBSD: builtin.c,v 1.1 2012/05/26 22:02:29 christos Exp $");
#include <sys/param.h>
#include <sys/types.h>
#include "execinfo.h"
#ifdef __MACHINE_STACK_GROWS_UP
#define BELOW >
#else
#define BELOW <
#endif
#ifdef __lint__
#define __builtin_frame_address(a) ((void *)a)
#endif
struct frameinfo {
struct frameinfo *next;
void *return_address;
};
size_t
backtrace(void **trace, size_t len)
{
const struct frameinfo *frame = __builtin_frame_address(0);
void *stack = &stack;
for (size_t i = 0; i < len; i++) {
if ((const void *)frame BELOW stack)
return i;
trace[i] = frame->return_address;
frame = frame->next;
}
return len;
}

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/* $NetBSD: execinfo.h,v 1.1 2012/05/26 22:02:29 christos Exp $ */
/*-
* Copyright (c) 2012 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Christos Zoulas.
*
* 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
*/
#ifndef _EXECINFO_H_
#define _EXECINFO_H_
__BEGIN_DECLS
size_t backtrace(void **, size_t);
char **backtrace_symbols(void *const *, size_t);
int backtrace_symbols_fd(void *const *, size_t, int);
char **backtrace_symbols_fmt(void *const *, size_t, const char *);
int backtrace_symbols_fd_fmt(void *const *, size_t, int, const char *);
__END_DECLS
#endif /* _EXECINFO_H_ */

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# $NetBSD: shlib_version,v 1.1 2012/05/26 22:02:29 christos Exp $
major=0
minor=0

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lib/libexecinfo/symtab.c Normal file
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/* $NetBSD: symtab.c,v 1.1 2012/05/26 22:02:29 christos Exp $ */
/*-
* Copyright (c) 2012 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Christos Zoulas.
*
* 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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 <sys/cdefs.h>
__RCSID("$NetBSD: symtab.c,v 1.1 2012/05/26 22:02:29 christos Exp $");
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <err.h>
#include <dlfcn.h>
#include <libelf.h>
#include <gelf.h>
#ifndef ELF_ST_BIND
#define ELF_ST_BIND(x) ((x) >> 4)
#endif
#ifndef ELF_ST_TYPE
#define ELF_ST_TYPE(x) (((unsigned int)x) & 0xf)
#endif
#include "symtab.h"
struct symbol {
char *st_name;
uintptr_t st_value;
uintptr_t st_info;
};
struct symtab {
size_t nsymbols;
struct symbol *symbols;
};
static int
address_compare(const void *a, const void *b)
{
const struct symbol *sa = a;
const struct symbol *sb = b;
return (int)(intmax_t)(sa->st_value - sb->st_value);
}
void
symtab_destroy(symtab_t *s)
{
if (s == NULL)
return;
for (size_t i = 0; i < s->nsymbols; i++)
free(s->symbols[i].st_name);
free(s->symbols);
free(s);
}
symtab_t *
symtab_create(int fd, int bind, int type)
{
Elf *elf;
symtab_t *st;
Elf_Scn *scn = NULL;
if (elf_version(EV_CURRENT) == EV_NONE) {
warnx("Elf Library is out of date.");
return NULL;
}
elf = elf_begin(fd, ELF_C_READ, NULL);
if (elf == NULL) {
warnx("Error opening elf file: %s", elf_errmsg(elf_errno()));
return NULL;
}
st = calloc(1, sizeof(*st));
if (st == NULL) {
warnx("Error allocating symbol table");
elf_end(elf);
return NULL;
}
while ((scn = elf_nextscn(elf, scn)) != NULL) {
GElf_Shdr shdr;
Elf_Data *edata;
size_t ns;
struct symbol *s;
gelf_getshdr(scn, &shdr);
if(shdr.sh_type != SHT_SYMTAB)
continue;
edata = elf_getdata(scn, NULL);
ns = shdr.sh_size / shdr.sh_entsize;
s = calloc(ns, sizeof(*s));
if (s == NULL) {
warn("Cannot allocate %zu symbols", ns);
goto out;
}
st->symbols = s;
for (size_t i = 0; i < ns; i++) {
GElf_Sym sym;
gelf_getsym(edata, (int)i, &sym);
if (bind != -1 &&
(unsigned)bind != ELF_ST_BIND(sym.st_info))
continue;
if (type != -1 &&
(unsigned)type != ELF_ST_TYPE(sym.st_info))
continue;
s->st_value = sym.st_value;
s->st_info = sym.st_info;
s->st_name = strdup(
elf_strptr(elf, shdr.sh_link, sym.st_name));
if (s->st_name == NULL)
goto out;
s++;
}
st->nsymbols = s - st->symbols;
if (st->nsymbols == 0) {
warnx("No symbols found");
goto out;
}
qsort(st->symbols, st->nsymbols, sizeof(*st->symbols),
address_compare);
elf_end(elf);
return st;
}
out:
symtab_destroy(st);
elf_end(elf);
return NULL;
}
int
symtab_find(const symtab_t *st, const void *p, Dl_info *dli)
{
struct symbol *s = st->symbols;
size_t ns = st->nsymbols;
size_t hi = ns;
size_t lo = 0;
size_t mid = ns / 2;
uintptr_t dd, sd, me = (uintptr_t)p;
for (;;) {
if (s[mid].st_value < me)
lo = mid;
else if (s[mid].st_value > me)
hi = mid;
else
break;
if (hi - lo == 1) {
mid = lo;
break;
}
mid = (hi + lo) / 2;
}
dd = me - (uintptr_t)dli->dli_saddr;
sd = me - s[mid].st_value;
if (dd > sd) {
dli->dli_saddr = (void *)s[mid].st_value;
dli->dli_sname = s[mid].st_name;
}
return 1;
}

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/* $NetBSD: symtab.h,v 1.1 2012/05/26 22:02:29 christos Exp $ */
/*-
* Copyright (c) 2012 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Christos Zoulas.
*
* 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
*/
#ifndef _SYMTAB_H_
#define _SYMTAB_H_
__BEGIN_DECLS
typedef struct symtab symtab_t;
void symtab_destroy(symtab_t *);
symtab_t * symtab_create(int, int, int);
int symtab_find(const symtab_t *, const void *, Dl_info *);
__END_DECLS
#endif /* _SYMTAB_H_ */

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lib/libexecinfo/unwind.c Normal file
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/* $NetBSD: unwind.c,v 1.1 2012/05/26 22:02:29 christos Exp $ */
/*-
* Copyright (c) 2012 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Christos Zoulas.
*
* 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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 <sys/cdefs.h>
#include <sys/types.h>
#include <stdio.h>
#include "unwind.h"
#include "execinfo.h"
struct tracer_context {
void **arr;
size_t len;
size_t n;
};
static _Unwind_Reason_Code
tracer(struct _Unwind_Context *ctx, void *arg)
{
struct tracer_context *t = arg;
if (t->n == (size_t)~0) {
/* Skip backtrace frame */
t->n = 0;
return 0;
}
if (t->n < t->len)
t->arr[t->n++] = _Unwind_GetIP(ctx);
return 0;
}
size_t
backtrace(void **arr, size_t len)
{
struct tracer_context ctx;
ctx.arr = arr;
ctx.len = len;
ctx.n = (size_t)~0;
_Unwind_Backtrace(tracer, &ctx);
if (ctx.n != (size_t)~0 && ctx.n > 0)
ctx.arr[--ctx.n] = NULL; /* Skip frame below __start */
return ctx.n;
}

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lib/libexecinfo/unwind.h Normal file
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@ -0,0 +1,68 @@
/* $NetBSD: unwind.h,v 1.1 2012/05/26 22:02:29 christos Exp $ */
/*-
* Copyright (c) 2012 The NetBSD Foundation, Inc.
* 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
*/
#ifndef _UNWIND_H_
#define _UNWIND_H_
__BEGIN_DECLS
struct _Unwind_Context;
struct _Unwind_Exception;
typedef int _Unwind_Reason_Code;
typedef void *_Unwind_Ptr;
typedef long _Unwind_Word;
typedef _Unwind_Reason_Code
(*_Unwind_Trace_Fn)(struct _Unwind_Context *, void *);
#ifdef notyet
typedef _Unwind_Reason_Code
(*_Unwind_Stop_Fn)(struct _Unwind_Context *, void *);
#endif
_Unwind_Reason_Code _Unwind_Backtrace(_Unwind_Trace_Fn, void *);
void _Unwind_DeleteException(struct _Unwind_Exception *);
void *_Unwind_FindEnclosingFunction(void *);
#ifdef notyet
_Unwind_Reason_Code _Unwind_ForcedUnwind(struct _Unwind_Exception *,
_Unwind_Stop_fn, void *);
#endif
_Unwind_Word _Unwind_GetCFA(struct _Unwind_Context *);
_Unwind_Ptr _Unwind_GetDataRelBase(struct _Unwind_Context *);
_Unwind_Word _Unwind_GetGR(struct _Unwind_Context *, int);
_Unwind_Ptr _Unwind_GetIP(struct _Unwind_Context *);
_Unwind_Ptr _Unwind_GetIPInfo(struct _Unwind_Context *, int *);
void *_Unwind_GetLanguageSpecificData(
struct _Unwind_Context *);
_Unwind_Ptr _Unwind_GetRegionStart(struct _Unwind_Context *);
_Unwind_Ptr _Unwind_GetTextRelBase(struct _Unwind_Context *);
_Unwind_Reason_Code _Unwind_RaiseException(struct _Unwind_Exception *);
void _Unwind_Resume(struct _Unwind_Exception *);
_Unwind_Reason_Code _Unwind_Resume_or_Rethrow(struct _Unwind_Exception *);
void _Unwind_SetGR(struct _Unwind_Context *, int,
_Unwind_Ptr);
void _Unwind_SetIP(struct _Unwind_Context *, _Unwind_Ptr);
__END_DECLS
#endif /* _UNWIND_H_ */