| 0,0 → 1,275 |
|---|
| /* |
| * 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 rtld |
| * @brief |
| * @{ |
| */ |
| /** |
| * @file |
| */ |
| |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <unistd.h> |
| #include <fcntl.h> |
| #include <libadt/list.h> |
| #include <loader/pcb.h> |
| |
| #include <rtld.h> |
| #include <dynamic.h> |
| #include <elf_load.h> |
| #include <rtld_arch.h> |
| #include <module.h> |
| |
| /** (Eagerly) process all relocation tables in a module. |
| * |
| * Currently works as if LD_BIND_NOW was specified. |
| */ |
| void module_process_relocs(module_t *m) |
| { |
| DPRINTF("module_process_relocs('%s')\n", m->dyn.soname); |
| |
| /* Do not relocate twice. */ |
| if (m->relocated) return; |
| |
| module_process_pre_arch(m); |
| |
| if (m->dyn.plt_rel == DT_REL) { |
| DPRINTF("table type DT_REL\n"); |
| if (m->dyn.rel != NULL) { |
| DPRINTF("non-empty\n"); |
| rel_table_process(m, m->dyn.rel, m->dyn.rel_sz); |
| } |
| /* FIXME: this seems wrong */ |
| if (m->dyn.jmp_rel != NULL) { |
| DPRINTF("table type jmp-rel\n"); |
| DPRINTF("non-empty\n"); |
| rel_table_process(m, m->dyn.jmp_rel, m->dyn.plt_rel_sz); |
| } |
| } else { /* (m->dyn.plt_rel == DT_RELA) */ |
| DPRINTF("table type DT_RELA\n"); |
| if (m->dyn.rela != NULL) { |
| DPRINTF("non-empty\n"); |
| rela_table_process(m, m->dyn.rela, m->dyn.rela_sz); |
| } |
| } |
| |
| m->relocated = true; |
| } |
| |
| /** Find module structure by soname/pathname. |
| * |
| * Used primarily to see if a module has already been loaded. |
| * Modules are compared according to their soname, i.e. possible |
| * path components are ignored. |
| */ |
| module_t *module_find(char *name) |
| { |
| link_t *head = &runtime_env->modules_head; |
| |
| link_t *cur; |
| module_t *m; |
| char *p, *soname; |
| |
| /* |
| * If name contains slashes, treat it as a pathname and |
| * construct soname by chopping off the path. Otherwise |
| * treat it as soname. |
| */ |
| p = str_rchr(name, '/'); |
| soname = p ? (p + 1) : name; |
| |
| /* Traverse list of all modules. Not extremely fast, but simple */ |
| for (cur = head->next; cur != head; cur = cur->next) { |
| m = list_get_instance(cur, module_t, modules_link); |
| if (str_cmp(m->dyn.soname, soname) == 0) { |
| return m; /* Found */ |
| } |
| } |
| |
| return NULL; /* Not found */ |
| } |
| |
| #define NAME_BUF_SIZE 64 |
| |
| /** Load a module. |
| * |
| * Currently this trivially tries to load '/<name>'. |
| */ |
| module_t *module_load(char *name) |
| { |
| elf_info_t info; |
| char name_buf[NAME_BUF_SIZE]; |
| module_t *m; |
| int rc; |
| |
| m = malloc(sizeof(module_t)); |
| if (!m) { |
| printf("malloc failed\n"); |
| exit(1); |
| } |
| |
| if (str_size(name) > NAME_BUF_SIZE - 2) { |
| printf("soname too long. increase NAME_BUF_SIZE\n"); |
| exit(1); |
| } |
| |
| /* Prepend soname with '/lib/' */ |
| str_cpy(name_buf, NAME_BUF_SIZE, "/lib/"); |
| str_cpy(name_buf + 5, NAME_BUF_SIZE - 5, name); |
| |
| /* FIXME: need to real allocation of address space */ |
| m->bias = runtime_env->next_bias; |
| runtime_env->next_bias += 0x100000; |
| |
| DPRINTF("filename:'%s'\n", name_buf); |
| printf("load '%s' at 0x%x\n", name_buf, m->bias); |
| |
| rc = elf_load_file(name_buf, m->bias, ELDF_RW, &info); |
| if (rc != EE_OK) { |
| printf("Failed to load '%s'\n", name_buf); |
| exit(1); |
| } |
| |
| if (info.dynamic == NULL) { |
| printf("Error: '%s' is not a dynamically-linked object.\n", |
| name_buf); |
| exit(1); |
| } |
| |
| /* Pending relocation. */ |
| m->relocated = false; |
| |
| DPRINTF("parse dynamic section\n"); |
| /* Parse ELF .dynamic section. Store info to m->dyn. */ |
| dynamic_parse(info.dynamic, m->bias, &m->dyn); |
| |
| /* Insert into the list of loaded modules */ |
| list_append(&m->modules_link, &runtime_env->modules_head); |
| |
| return m; |
| } |
| |
| /** Load all modules on which m (transitively) depends. |
| */ |
| void module_load_deps(module_t *m) |
| { |
| elf_dyn_t *dp; |
| char *dep_name; |
| module_t *dm; |
| size_t n, i; |
| |
| /* Count direct dependencies */ |
| |
| dp = m->dyn.dynamic; |
| n = 0; |
| |
| while (dp->d_tag != DT_NULL) { |
| if (dp->d_tag == DT_NEEDED) ++n; |
| ++dp; |
| } |
| |
| /* Create an array of pointers to direct dependencies */ |
| |
| m->n_deps = n; |
| |
| if (n == 0) { |
| /* There are no dependencies, so we are done. */ |
| m->deps = NULL; |
| return; |
| } |
| |
| m->deps = malloc(n * sizeof(module_t *)); |
| if (!m->deps) { |
| printf("malloc failed\n"); |
| exit(1); |
| } |
| |
| i = 0; /* Current dependency index */ |
| dp = m->dyn.dynamic; |
| |
| while (dp->d_tag != DT_NULL) { |
| if (dp->d_tag == DT_NEEDED) { |
| dep_name = m->dyn.str_tab + dp->d_un.d_val; |
| |
| DPRINTF("%s needs %s\n", m->dyn.soname, dep_name); |
| dm = module_find(dep_name); |
| if (!dm) { |
| dm = module_load(dep_name); |
| module_load_deps(dm); |
| } |
| |
| /* Save into deps table */ |
| m->deps[i++] = dm; |
| } |
| ++dp; |
| } |
| } |
| |
| /** Process relocations in modules. |
| * |
| * Processes relocations in @a start and all its dependencies. |
| * Modules that have already been relocated are unaffected. |
| * |
| * @param start The module where to start from. |
| */ |
| void modules_process_relocs(module_t *start) |
| { |
| link_t *head = &runtime_env->modules_head; |
| |
| link_t *cur; |
| module_t *m; |
| |
| for (cur = head->next; cur != head; cur = cur->next) { |
| m = list_get_instance(cur, module_t, modules_link); |
| |
| /* Skip rtld, since it has already been processed */ |
| if (m != &runtime_env->rtld) { |
| module_process_relocs(m); |
| } |
| } |
| } |
| |
| /** Clear BFS tags of all modules. |
| */ |
| void modules_untag(void) |
| { |
| link_t *head = &runtime_env->modules_head; |
| |
| link_t *cur; |
| module_t *m; |
| |
| for (cur = head->next; cur != head; cur = cur->next) { |
| m = list_get_instance(cur, module_t, modules_link); |
| m->bfs_tag = false; |
| } |
| } |
| |
| /** @} |
| */ |