/**************************************************************************** * binfmt/libelf/libelf_addrenv.c * * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. The * ASF licenses this file to you under the Apache License, Version 2.0 (the * "License"); you may not use this file except in compliance with the * License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the * License for the specific language governing permissions and limitations * under the License. * ****************************************************************************/ /**************************************************************************** * Included Files ****************************************************************************/ #include #include #include #include #include #include #include #include "libelf.h" /**************************************************************************** * Pre-processor Definitions ****************************************************************************/ #define ELF_TEXT_WRE (PROT_READ | PROT_WRITE | PROT_EXEC) #define ELF_TEXT_RE (PROT_READ | PROT_EXEC) /**************************************************************************** * Private Constant Data ****************************************************************************/ /**************************************************************************** * Private Functions ****************************************************************************/ /**************************************************************************** * Public Functions ****************************************************************************/ /**************************************************************************** * Name: elf_addrenv_alloc * * Description: * Allocate memory for the ELF image (textalloc and dataalloc). If * CONFIG_ARCH_ADDRENV=n, textalloc will be allocated using kmm_zalloc() * and dataalloc will be a offset from textalloc. If * CONFIG_ARCH_ADDRENV=y, then textalloc and dataalloc will be allocated * using up_addrenv_create(). In either case, there will be a unique * instance of textalloc and dataalloc (and stack) for each instance of a * process. * * Input Parameters: * loadinfo - Load state information * textsize - The size (in bytes) of the .text address environment needed * for the ELF image (read/execute). * datasize - The size (in bytes) of the .bss/.data address environment * needed for the ELF image (read/write). * heapsize - The initial size (in bytes) of the heap address environment * needed by the task. This region may be read/write only. * * Returned Value: * Zero (OK) on success; a negated errno value on failure. * ****************************************************************************/ int elf_addrenv_alloc(FAR struct elf_loadinfo_s *loadinfo, size_t textsize, size_t datasize, size_t heapsize) { #ifdef CONFIG_ARCH_ADDRENV FAR struct arch_addrenv_s *addrenv; FAR void *vtext; FAR void *vdata; int ret; /* Create an address environment for the new ELF task */ loadinfo->addrenv = addrenv_allocate(); if (!loadinfo->addrenv) { return -ENOMEM; } /* Start creating the address environment sections */ addrenv = &loadinfo->addrenv->addrenv; ret = up_addrenv_create(textsize, datasize, heapsize, addrenv); if (ret < 0) { berr("ERROR: up_addrenv_create failed: %d\n", ret); goto errout_with_addrenv; } /* Get the virtual address associated with the start of the address * environment. This is the base address that we will need to use to * access the ELF image (but only if the address environment has been * selected. */ ret = up_addrenv_vtext(addrenv, &vtext); if (ret < 0) { berr("ERROR: up_addrenv_vtext failed: %d\n", ret); goto errout_with_addrenv; } ret = up_addrenv_vdata(addrenv, textsize, &vdata); if (ret < 0) { berr("ERROR: up_addrenv_vdata failed: %d\n", ret); goto errout_with_addrenv; } loadinfo->textalloc = (uintptr_t)vtext; loadinfo->dataalloc = (uintptr_t)vdata; return OK; errout_with_addrenv: addrenv_drop(loadinfo->addrenv, false); return ret; #else if (loadinfo->ehdr.e_type == ET_EXEC) { return OK; } /* Allocate memory to hold the ELF image */ # if defined(CONFIG_ARCH_USE_TEXT_HEAP) loadinfo->textalloc = (uintptr_t) up_textheap_memalign(loadinfo->textalign, textsize); # else loadinfo->textalloc = (uintptr_t) kumm_memalign(loadinfo->textalign, textsize); # endif if (!loadinfo->textalloc) { return -ENOMEM; } if (loadinfo->datasize > 0) { loadinfo->dataalloc = (uintptr_t) kumm_memalign(loadinfo->dataalign, datasize); if (!loadinfo->dataalloc) { return -ENOMEM; } } return OK; #endif } /**************************************************************************** * Name: elf_addrenv_select * * Description: * Temporarily select the task's address environment. * * Input Parameters: * loadinfo - Load state information * * Returned Value: * Zero (OK) on success; a negated errno value on failure. * ****************************************************************************/ #ifdef CONFIG_ARCH_ADDRENV int elf_addrenv_select(FAR struct elf_loadinfo_s *loadinfo) { int ret; /* Instantiate the new address environment */ ret = addrenv_select(loadinfo->addrenv, &loadinfo->oldenv); if (ret < 0) { berr("ERROR: addrenv_select failed: %d\n", ret); return ret; } /* Allow write access to .text */ ret = up_addrenv_mprot(&loadinfo->addrenv->addrenv, loadinfo->textalloc, loadinfo->textsize, ELF_TEXT_WRE); if (ret < 0) { berr("ERROR: up_addrenv_text_enable_write failed: %d\n", ret); return ret; } return OK; } #endif /**************************************************************************** * Name: elf_addrenv_restore * * Description: * Restore the address environment before elf_addrenv_select() was called.. * * Input Parameters: * loadinfo - Load state information * * Returned Value: * Zero (OK) on success; a negated errno value on failure. * ****************************************************************************/ #ifdef CONFIG_ARCH_ADDRENV int elf_addrenv_restore(FAR struct elf_loadinfo_s *loadinfo) { int ret; /* Remove write access to .text */ ret = up_addrenv_mprot(&loadinfo->addrenv->addrenv, loadinfo->textalloc, loadinfo->textsize, ELF_TEXT_RE); if (ret < 0) { berr("ERROR: up_addrenv_text_disable_write failed: %d\n", ret); return ret; } /* Restore the old address environment */ ret = addrenv_restore(loadinfo->oldenv); if (ret < 0) { berr("ERROR: addrenv_restore failed: %d\n", ret); return ret; } return OK; } #endif /**************************************************************************** * Name: elf_addrenv_free * * Description: * Release the address environment previously created by * elf_addrenv_alloc(). This function is called only under certain error * conditions after the module has been loaded but not yet started. * After the module has been started, the address environment will * automatically be freed when the module exits. * * Input Parameters: * loadinfo - Load state information * * Returned Value: * None. * ****************************************************************************/ void elf_addrenv_free(FAR struct elf_loadinfo_s *loadinfo) { #ifdef CONFIG_ARCH_ADDRENV /* Free the address environment */ addrenv_drop(loadinfo->addrenv, false); #else if (loadinfo->textalloc != 0) { # if defined(CONFIG_ARCH_USE_TEXT_HEAP) up_textheap_free((FAR void *)loadinfo->textalloc); # else kumm_free((FAR void *)loadinfo->textalloc); # endif } if (loadinfo->dataalloc != 0) { kumm_free((FAR void *)loadinfo->dataalloc); } #endif /* Clear out all indications of the allocated address environment */ loadinfo->textalloc = 0; loadinfo->dataalloc = 0; loadinfo->textsize = 0; loadinfo->datasize = 0; }