/**************************************************************************** * binfmt/libelf/libelf_init.c * * Copyright (C) 2012 Gregory Nutt. All rights reserved. * Author: Gregory Nutt * * 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. * 3. Neither the name NuttX nor the names of its contributors may be * used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 * COPYRIGHT OWNER 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. * ****************************************************************************/ /**************************************************************************** * Included Files ****************************************************************************/ #include #include #include #include #include #include #include #include #include #include "libelf.h" /**************************************************************************** * Pre-processor Definitions ****************************************************************************/ /* CONFIG_DEBUG, CONFIG_DEBUG_VERBOSE, and CONFIG_DEBUG_BINFMT have to be * defined or CONFIG_ELF_DUMPBUFFER does nothing. */ #if !defined(CONFIG_DEBUG_VERBOSE) || !defined (CONFIG_DEBUG_BINFMT) # undef CONFIG_ELF_DUMPBUFFER #endif #ifdef CONFIG_ELF_DUMPBUFFER # define elf_dumpbuffer(m,b,n) bvdbgdumpbuffer(m,b,n) #else # define elf_dumpbuffer(m,b,n) #endif /**************************************************************************** * Private Constant Data ****************************************************************************/ /**************************************************************************** * Private Functions ****************************************************************************/ /**************************************************************************** * Name: elf_filelen * * Description: * Get the size of the ELF file * * Returned Value: * 0 (OK) is returned on success and a negated errno is returned on * failure. * ****************************************************************************/ static inline int elf_filelen(FAR struct elf_loadinfo_s *loadinfo, FAR const char *filename) { struct stat buf; int ret; /* Get the file stats */ ret = stat(filename, &buf); if (ret < 0) { int errval = errno; bdbg("Failed to fstat file: %d\n", errval); return -errval; } /* Verify that it is a regular file */ if (!S_ISREG(buf.st_mode)) { bdbg("Not a regular file. mode: %d\n", buf.st_mode); return -ENOENT; } /* TODO: Verify that the file is readable. Not really important because * we will detect this when we try to open the file read-only. */ /* Return the size of the file in the loadinfo structure */ loadinfo->filelen = buf.st_size; return OK; } /**************************************************************************** * Public Functions ****************************************************************************/ /**************************************************************************** * Name: elf_init * * Description: * This function is called to configure the library to process an ELF * program binary. * * Returned Value: * 0 (OK) is returned on success and a negated errno is returned on * failure. * ****************************************************************************/ int elf_init(FAR const char *filename, FAR struct elf_loadinfo_s *loadinfo) { int ret; bvdbg("filename: %s loadinfo: %p\n", filename, loadinfo); /* Clear the load info structure */ memset(loadinfo, 0, sizeof(struct elf_loadinfo_s)); /* Get the length of the file. */ ret = elf_filelen(loadinfo, filename); if (ret < 0) { bdbg("elf_filelen failed: %d\n", ret); return ret; } /* Open the binary file for reading (only) */ loadinfo->filfd = open(filename, O_RDONLY); if (loadinfo->filfd < 0) { int errval = errno; bdbg("Failed to open ELF binary %s: %d\n", filename, errval); return -errval; } /* Read the ELF ehdr from offset 0 */ ret = elf_read(loadinfo, (FAR uint8_t*)&loadinfo->ehdr, sizeof(Elf32_Ehdr), 0); if (ret < 0) { bdbg("Failed to read ELF header: %d\n", ret); return ret; } elf_dumpbuffer("ELF header", (FAR const uint8_t*)&loadinfo->ehdr, sizeof(Elf32_Ehdr)); /* Verify the ELF header */ ret = elf_verifyheader(&loadinfo->ehdr); if (ret <0) { /* This may not be an error because we will be called to attempt loading * EVERY binary. If elf_verifyheader() does not recognize the ELF header, * it will -ENOEXEC whcih simply informs the system that the file is not an * ELF file. elf_verifyheader() will return other errors if the ELF header * is not correctly formed. */ bdbg("Bad ELF header: %d\n", ret); return ret; } return OK; }