freebsd-dev/libexec/rtld-elf/debug.c
Konstantin Belousov 9fee0541f2 Do not call callbacks for dl_iterate_phdr(3) with the rtld bind and
phdr locks locked.  This allows to call rtld services from the
callback, which is only reasonable for dlopen(path, RTLD_NOLOAD) to
test existence of the library in the image, and for dlsym().  The
later might still be not quite safe, due to the lazy resolution of
filters.

To allow dropping the locks around iteration in dl_iterate_phdr(3), we
insert markers to track current position between relocks.  The global
objects list is converted to tailq and all iterators skip markers,
globallist_next() and globallist_curr() helpers are added.

Reported and tested by:	davide
Reviewed by:	kan
Sponsored by:	The FreeBSD Foundation
MFC after:	3 weeks
2016-01-20 07:21:33 +00:00

145 lines
4.2 KiB
C

/*-
* Copyright 1996-1998 John D. Polstra.
* 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 ``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 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.
*
* $FreeBSD$
*/
/*
* Support for printing debugging messages.
*/
#include <stdarg.h>
#include <stdio.h>
#include "debug.h"
#include "rtld.h"
#include "rtld_printf.h"
static const char rel_header[] =
" symbol name r_info r_offset st_value st_size address value\n"
" ------------------------------------------------------------------------------\n";
static const char rel_format[] = " %-25s %6lx %08lx %08lx %7d %10p %08lx\n";
int debug = 0;
void
debug_printf(const char *format, ...)
{
if (debug) {
va_list ap;
va_start(ap, format);
rtld_vfdprintf(STDERR_FILENO, format, ap);
rtld_fdputchar(STDERR_FILENO, '\n');
va_end(ap);
}
}
void
dump_relocations (Obj_Entry *obj0)
{
Obj_Entry *obj;
for (obj = globallist_curr(obj0); obj != NULL;
obj = globallist_next(obj)) {
dump_obj_relocations(obj);
}
}
void
dump_obj_relocations (Obj_Entry *obj)
{
rtld_printf("Object \"%s\", relocbase %p\n", obj->path, obj->relocbase);
if (obj->relsize) {
rtld_printf("Non-PLT Relocations: %ld\n",
(obj->relsize / sizeof(Elf_Rel)));
dump_Elf_Rel(obj, obj->rel, obj->relsize);
}
if (obj->relasize) {
rtld_printf("Non-PLT Relocations with Addend: %ld\n",
(obj->relasize / sizeof(Elf_Rela)));
dump_Elf_Rela(obj, obj->rela, obj->relasize);
}
if (obj->pltrelsize) {
rtld_printf("PLT Relocations: %ld\n",
(obj->pltrelsize / sizeof(Elf_Rel)));
dump_Elf_Rel(obj, obj->pltrel, obj->pltrelsize);
}
if (obj->pltrelasize) {
rtld_printf("PLT Relocations with Addend: %ld\n",
(obj->pltrelasize / sizeof(Elf_Rela)));
dump_Elf_Rela(obj, obj->pltrela, obj->pltrelasize);
}
}
void
dump_Elf_Rel (Obj_Entry *obj, const Elf_Rel *rel0, u_long relsize)
{
const Elf_Rel *rel;
const Elf_Rel *rellim;
const Elf_Sym *sym;
Elf_Addr *dstaddr;
rtld_putstr(rel_header);
rellim = (const Elf_Rel *)((const char *)rel0 + relsize);
for (rel = rel0; rel < rellim; rel++) {
dstaddr = (Elf_Addr *)(obj->relocbase + rel->r_offset);
sym = obj->symtab + ELF_R_SYM(rel->r_info);
rtld_printf(rel_format,
obj->strtab + sym->st_name,
(u_long)rel->r_info, (u_long)rel->r_offset,
(u_long)sym->st_value, (int)sym->st_size,
dstaddr, (u_long)*dstaddr);
}
return;
}
void
dump_Elf_Rela (Obj_Entry *obj, const Elf_Rela *rela0, u_long relasize)
{
const Elf_Rela *rela;
const Elf_Rela *relalim;
const Elf_Sym *sym;
Elf_Addr *dstaddr;
rtld_putstr(rel_header);
relalim = (const Elf_Rela *)((const char *)rela0 + relasize);
for (rela = rela0; rela < relalim; rela++) {
dstaddr = (Elf_Addr *)(obj->relocbase + rela->r_offset);
sym = obj->symtab + ELF_R_SYM(rela->r_info);
rtld_printf(rel_format,
obj->strtab + sym->st_name,
(u_long)rela->r_info, (u_long)rela->r_offset,
(u_long)sym->st_value, (int)sym->st_size,
dstaddr, (u_long)*dstaddr);
}
return;
}