/**************************************************************************** * binfmt/elf.c * * Copyright (C) 2012, 2014 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 #include #include "libelf/libelf.h" #ifdef CONFIG_ELF /**************************************************************************** * 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 #ifndef CONFIG_ELF_STACKSIZE # define CONFIG_ELF_STACKSIZE 2048 #endif #ifdef CONFIG_ELF_DUMPBUFFER # define elf_dumpbuffer(m,b,n) bvdbgdumpbuffer(m,b,n) #else # define elf_dumpbuffer(m,b,n) #endif #ifndef MIN # define MIN(a,b) (a < b ? a : b) #endif /**************************************************************************** * Private Function Prototypes ****************************************************************************/ static int elf_loadbinary(FAR struct binary_s *binp); #if defined(CONFIG_DEBUG) && defined(CONFIG_DEBUG_BINFMT) static void elf_dumploadinfo(FAR struct elf_loadinfo_s *loadinfo); #endif /**************************************************************************** * Private Data ****************************************************************************/ static struct binfmt_s g_elfbinfmt = { NULL, /* next */ elf_loadbinary, /* load */ NULL, /* unload */ }; /**************************************************************************** * Private Functions ****************************************************************************/ /**************************************************************************** * Name: elf_dumploadinfo ****************************************************************************/ #if defined(CONFIG_DEBUG) && defined(CONFIG_DEBUG_BINFMT) static void elf_dumploadinfo(FAR struct elf_loadinfo_s *loadinfo) { int i; bdbg("LOAD_INFO:\n"); bdbg(" textalloc: %08lx\n", (long)loadinfo->textalloc); bdbg(" dataalloc: %08lx\n", (long)loadinfo->dataalloc); bdbg(" textsize: %ld\n", (long)loadinfo->textsize); bdbg(" datasize: %ld\n", (long)loadinfo->datasize); bdbg(" filelen: %ld\n", (long)loadinfo->filelen); #ifdef CONFIG_BINFMT_CONSTRUCTORS bdbg(" ctoralloc: %08lx\n", (long)loadinfo->ctoralloc); bdbg(" ctors: %08lx\n", (long)loadinfo->ctors); bdbg(" nctors: %d\n", loadinfo->nctors); bdbg(" dtoralloc: %08lx\n", (long)loadinfo->dtoralloc); bdbg(" dtors: %08lx\n", (long)loadinfo->dtors); bdbg(" ndtors: %d\n", loadinfo->ndtors); #endif bdbg(" filfd: %d\n", loadinfo->filfd); bdbg(" symtabidx: %d\n", loadinfo->symtabidx); bdbg(" strtabidx: %d\n", loadinfo->strtabidx); bdbg("ELF Header:\n"); bdbg(" e_ident: %02x %02x %02x %02x\n", loadinfo->ehdr.e_ident[0], loadinfo->ehdr.e_ident[1], loadinfo->ehdr.e_ident[2], loadinfo->ehdr.e_ident[3]); bdbg(" e_type: %04x\n", loadinfo->ehdr.e_type); bdbg(" e_machine: %04x\n", loadinfo->ehdr.e_machine); bdbg(" e_version: %08x\n", loadinfo->ehdr.e_version); bdbg(" e_entry: %08lx\n", (long)loadinfo->ehdr.e_entry); bdbg(" e_phoff: %d\n", loadinfo->ehdr.e_phoff); bdbg(" e_shoff: %d\n", loadinfo->ehdr.e_shoff); bdbg(" e_flags: %08x\n" , loadinfo->ehdr.e_flags); bdbg(" e_ehsize: %d\n", loadinfo->ehdr.e_ehsize); bdbg(" e_phentsize: %d\n", loadinfo->ehdr.e_phentsize); bdbg(" e_phnum: %d\n", loadinfo->ehdr.e_phnum); bdbg(" e_shentsize: %d\n", loadinfo->ehdr.e_shentsize); bdbg(" e_shnum: %d\n", loadinfo->ehdr.e_shnum); bdbg(" e_shstrndx: %d\n", loadinfo->ehdr.e_shstrndx); if (loadinfo->shdr && loadinfo->ehdr.e_shnum > 0) { for (i = 0; i < loadinfo->ehdr.e_shnum; i++) { FAR Elf32_Shdr *shdr = &loadinfo->shdr[i]; bdbg("Sections %d:\n", i); bdbg(" sh_name: %08x\n", shdr->sh_name); bdbg(" sh_type: %08x\n", shdr->sh_type); bdbg(" sh_flags: %08x\n", shdr->sh_flags); bdbg(" sh_addr: %08x\n", shdr->sh_addr); bdbg(" sh_offset: %d\n", shdr->sh_offset); bdbg(" sh_size: %d\n", shdr->sh_size); bdbg(" sh_link: %d\n", shdr->sh_link); bdbg(" sh_info: %d\n", shdr->sh_info); bdbg(" sh_addralign: %d\n", shdr->sh_addralign); bdbg(" sh_entsize: %d\n", shdr->sh_entsize); } } } #else # define elf_dumploadinfo(i) #endif /**************************************************************************** * Name: elf_dumpentrypt ****************************************************************************/ #ifdef CONFIG_ELF_DUMPBUFFER static void elf_dumpentrypt(FAR struct binary_s *binp, FAR struct elf_loadinfo_s *loadinfo) { #ifdef CONFIG_ARCH_ADDRENV int ret; /* If CONFIG_ARCH_ADDRENV=y, then the loaded ELF lies in a virtual address * space that may not be in place now. elf_addrenv_select() will * temporarily instantiate that address space. */ ret = elf_addrenv_select(loadinfo); if (ret < 0) { bdbg("ERROR: elf_addrenv_select() failed: %d\n", ret); return; } #endif elf_dumpbuffer("Entry code", (FAR const uint8_t *)binp->entrypt, MIN(loadinfo->textsize - loadinfo->ehdr.e_entry, 512)); #ifdef CONFIG_ARCH_ADDRENV /* Restore the original address environment */ ret = elf_addrenv_restore(loadinfo); if (ret < 0) { bdbg("ERROR: elf_addrenv_restore() failed: %d\n", ret); } #endif } #else # define elf_dumpentrypt(b,l) #endif /**************************************************************************** * Name: elf_loadbinary * * Description: * Verify that the file is an ELF binary and, if so, load the ELF * binary into memory * ****************************************************************************/ static int elf_loadbinary(FAR struct binary_s *binp) { struct elf_loadinfo_s loadinfo; /* Contains globals for libelf */ int ret; bvdbg("Loading file: %s\n", binp->filename); /* Initialize the ELF library to load the program binary. */ ret = elf_init(binp->filename, &loadinfo); elf_dumploadinfo(&loadinfo); if (ret != 0) { bdbg("Failed to initialize for load of ELF program: %d\n", ret); goto errout; } /* Load the program binary */ ret = elf_load(&loadinfo); elf_dumploadinfo(&loadinfo); if (ret != 0) { bdbg("Failed to load ELF program binary: %d\n", ret); goto errout_with_init; } /* Bind the program to the exported symbol table */ ret = elf_bind(&loadinfo, binp->exports, binp->nexports); if (ret != 0) { bdbg("Failed to bind symbols program binary: %d\n", ret); goto errout_with_load; } /* Return the load information */ binp->entrypt = (main_t)(loadinfo.textalloc + loadinfo.ehdr.e_entry); binp->stacksize = CONFIG_ELF_STACKSIZE; /* Add the ELF allocation to the alloc[] only if there is no address * environment. If there is an address environment, it will automatically * be freed when the function exits * * REVISIT: If the module is loaded then unloaded, wouldn't this cause * a memory leak? */ #ifdef CONFIG_ARCH_ADDRENV # warning "REVISIT" #else binp->alloc[0] = (FAR void *)loadinfo.textalloc; #endif #ifdef CONFIG_BINFMT_CONSTRUCTORS /* Save information about constructors. NOTE: destructors are not * yet supported. */ binp->alloc[1] = loadinfo.ctoralloc; binp->ctors = loadinfo.ctors; binp->nctors = loadinfo.nctors; binp->alloc[2] = loadinfo.dtoralloc; binp->dtors = loadinfo.dtors; binp->ndtors = loadinfo.ndtors; #endif #ifdef CONFIG_ARCH_ADDRENV /* Save the address environment in the binfmt structure. This will be * needed when the module is executed. */ up_addrenv_clone(&loadinfo.addrenv, &binp->addrenv); #endif elf_dumpentrypt(binp, &loadinfo); elf_uninit(&loadinfo); return OK; errout_with_load: elf_unload(&loadinfo); errout_with_init: elf_uninit(&loadinfo); errout: return ret; } /**************************************************************************** * Public Functions ****************************************************************************/ /**************************************************************************** * Name: elf_initialize * * Description: * ELF support is built unconditionally. However, in order to * use this binary format, this function must be called during system * initialization in order to register the ELF binary format. * * Returned Value: * This is a NuttX internal function so it follows the convention that * 0 (OK) is returned on success and a negated errno is returned on * failure. * ****************************************************************************/ int elf_initialize(void) { int ret; /* Register ourselves as a binfmt loader */ bvdbg("Registering ELF\n"); ret = register_binfmt(&g_elfbinfmt); if (ret != 0) { bdbg("Failed to register binfmt: %d\n", ret); } return ret; } /**************************************************************************** * Name: elf_uninitialize * * Description: * Unregister the ELF binary loader * * Returned Value: * None * ****************************************************************************/ void elf_uninitialize(void) { unregister_binfmt(&g_elfbinfmt); } #endif /* CONFIG_ELF */