/*
* Copyright (c) 2008 Jiri Svoboda
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* - 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.
* - The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* 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.
*/
/** @addtogroup rtld
* @brief
* @{
*/
/**
* @file
*/
#include <errno.h>
#include <rtld/module.h>
#include <rtld/rtld.h>
#include <rtld/rtld_debug.h>
#include <stdlib.h>
#include <str.h>
rtld_t *runtime_env;
static rtld_t rt_env_static;
/** Initialize the runtime linker for use in a statically-linked executable. */
errno_t rtld_init_static(void)
{
errno_t rc;
runtime_env = &rt_env_static;
list_initialize(&runtime_env->modules);
list_initialize(&runtime_env->imodules);
runtime_env->program = NULL;
runtime_env->next_id = 1;
rc = module_create_static_exec(runtime_env, NULL);
if (rc != EOK)
return rc;
modules_process_tls(runtime_env);
return EOK;
}
/** Initialize and process a dynamically linked executable.
*
* @param p_info Program info
* @return EOK on success or non-zero error code
*/
errno_t rtld_prog_process(elf_finfo_t *p_info, rtld_t **rre)
{
rtld_t *env;
module_t *prog;
DPRINTF("Load dynamically linked program.\n");
/* Allocate new RTLD environment to pass to the loaded program */
env = calloc(1, sizeof(rtld_t));
if (env == NULL)
return ENOMEM;
env->next_id = 1;
prog = calloc(1, sizeof(module_t));
if (prog == NULL) {
free(env);
return ENOMEM;
}
/*
* First we need to process dynamic sections of the executable
* program and insert it into the module graph.
*/
DPRINTF("Parse program .dynamic section at %p\n", p_info->dynamic);
dynamic_parse(p_info->dynamic, 0, &prog->dyn);
prog->bias = 0;
prog->dyn.soname = "[program]";
prog->rtld = env;
prog->id = rtld_get_next_id(env);
prog->exec = true;
prog->local = false;
prog->tdata = p_info->tls.tdata;
prog->tdata_size = p_info->tls.tdata_size;
prog->tbss_size = p_info->tls.tbss_size;
prog->tls_align = p_info->tls.tls_align;
DPRINTF("prog tdata at %p size %zu, tbss size %zu\n",
prog->tdata, prog->tdata_size, prog->tbss_size);
/* Initialize list of loaded modules */
list_initialize(&env->modules);
list_initialize(&env->imodules);
list_append(&prog->modules_link, &env->modules);
/* Pointer to program module. Used as root of the module graph. */
env->program = prog;
/*
* Now we can continue with loading all other modules.
*/
DPRINTF("Load all program dependencies\n");
errno_t rc = module_load_deps(prog, 0);
if (rc != EOK) {
return rc;
}
/* Compute static TLS size */
modules_process_tls(env);
/*
* Now relocate/link all modules together.
*/
/* Process relocations in all modules */
DPRINTF("Relocate all modules\n");
modules_process_relocs(env, prog);
*rre = env;
return EOK;
}
/** Create TLS (Thread Local Storage) data structures.
*
* @return Pointer to TCB.
*/
tcb_t *rtld_tls_make(rtld_t *rtld)
{
tcb_t *tcb;
void **dtv;
size_t nmods;
size_t i;
tcb = tls_alloc_arch(rtld->tls_size, rtld->tls_align);
if (tcb == NULL)
return NULL;
/** Allocate dynamic thread vector */
nmods = list_count(&rtld->imodules);
dtv = malloc((nmods + 1) * sizeof(void *));
if (dtv == NULL) {
tls_free(tcb);
return NULL;
}
/*
* We define generation number to be equal to vector length.
* We start with a vector covering the initially loaded modules.
*/
DTV_GN(dtv) = nmods;
/*
* Copy thread local data from the initialization images of initial
* modules. Zero out thread-local uninitialized data.
*/
i = 1;
list_foreach(rtld->imodules, imodules_link, module_t, m) {
assert(i++ == m->id);
dtv[m->id] = (void *) tcb + m->tpoff;
assert(((uintptr_t) dtv[m->id]) % m->tls_align == 0);
if (m->tdata)
memcpy(dtv[m->id], m->tdata, m->tdata_size);
memset(dtv[m->id] + m->tdata_size, 0, m->tbss_size);
}
tcb->dtv = dtv;
return tcb;
}
unsigned long rtld_get_next_id(rtld_t *rtld)
{
return rtld->next_id++;
}
/** Get address of thread-local variable.
*
* @param rtld RTLD instance
* @param tcb TCB of the thread whose instance to return
* @param mod_id Module ID
* @param offset Offset within TLS block of the module
*
* @return Address of thread-local variable
*/
void *rtld_tls_get_addr(rtld_t *rtld, tcb_t *tcb, unsigned long mod_id,
unsigned long offset)
{
module_t *m;
size_t dtv_len;
void *tls_block;
dtv_len = DTV_GN(tcb->dtv);
if (dtv_len < mod_id) {
/* Vector is short */
tcb->dtv = realloc(tcb->dtv, (1 + mod_id) * sizeof(void *));
/* XXX This can fail if OOM */
assert(tcb->dtv != NULL);
/* Zero out new part of vector */
memset(tcb->dtv + (1 + dtv_len), 0, (mod_id - dtv_len) *
sizeof(void *));
}
if (tcb->dtv[mod_id] == NULL) {
/* TLS block is not allocated */
m = module_by_id(rtld, mod_id);
assert(m != NULL);
/* Should not be initial module, those have TLS pre-allocated */
assert(!link_used(&m->imodules_link));
tls_block = memalign(m->tls_align, m->tdata_size + m->tbss_size);
/* XXX This can fail if OOM */
assert(tls_block != NULL);
/* Copy tdata */
memcpy(tls_block, m->tdata, m->tdata_size);
/* Zero out tbss */
memset(tls_block + m->tdata_size, 0, m->tbss_size);
tcb->dtv[mod_id] = tls_block;
}
return (uint8_t *)(tcb->dtv[mod_id]) + offset;
}
/** @}
*/