/*- * Copyright (c) 1998 Michael Smith * Copyright (c) 1998 Peter Wemm * All rights reserved. * * 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. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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. * * $Id: load_elf.c,v 1.1 1998/09/30 19:38:26 peter Exp $ */ #include #include #include #include #include #include #include #define FREEBSD_ELF #include #include "bootstrap.h" static int elf_loadimage(struct loaded_module *mp, int fd, vm_offset_t *loadaddr, Elf_Ehdr *ehdr, int kernel); #if 0 static vm_offset_t elf_findkldident(struct loaded_module *mp, Elf_Ehdr *ehdr); static int elf_fixupkldmod(struct loaded_module *mp, Elf_Ehdr *ehdr); #endif char *elf_kerneltype = "elf kernel"; char *elf_moduletype = "elf module"; /* * Attempt to load the file (file) as an ELF module. It will be stored at * (dest), and a pointer to a module structure describing the loaded object * will be saved in (result). */ int elf_loadmodule(char *filename, vm_offset_t dest, struct loaded_module **result) { struct loaded_module *mp, *kmp; Elf_Ehdr ehdr; int fd; vm_offset_t addr; int err, kernel; u_int pad; mp = NULL; /* * Open the image, read and validate the ELF header */ if (filename == NULL) /* can't handle nameless */ return(EFTYPE); if ((fd = open(filename, O_RDONLY)) == -1) return(errno); if (read(fd, &ehdr, sizeof(ehdr)) != sizeof(ehdr)) { err = EFTYPE; /* could be EIO, but may be small file */ goto oerr; } /* Is it ELF? */ if (!IS_ELF(ehdr)) { err = EFTYPE; goto oerr; } if (ehdr.e_ident[EI_CLASS] != ELF_TARG_CLASS || /* Layout ? */ ehdr.e_ident[EI_DATA] != ELF_TARG_DATA || ehdr.e_ident[EI_VERSION] != EV_CURRENT || /* Version ? */ ehdr.e_version != EV_CURRENT || ehdr.e_machine != ELF_TARG_MACH) { /* Machine ? */ err = EFTYPE; goto oerr; } /* * Check to see what sort of module we are. */ kmp = mod_findmodule(NULL, NULL); if (ehdr.e_type == ET_DYN) { /* Looks like a kld module */ if (kmp == NULL) { printf("elf_loadmodule: can't load module before kernel\n"); err = EPERM; goto oerr; } if (strcmp(elf_kerneltype, kmp->m_type)) { printf("elf_loadmodule: can't load module with kernel type '%s'\n", kmp->m_type); err = EPERM; goto oerr; } /* Looks OK, got ahead */ kernel = 0; /* Page-align the load address */ addr = dest; pad = (u_int)addr & PAGE_MASK; if (pad != 0) { pad = PAGE_SIZE - pad; addr += pad; } } else if (ehdr.e_type == ET_EXEC) { /* Looks like a kernel */ if (kmp != NULL) { printf("elf_loadmodule: kernel already loaded\n"); err = EPERM; goto oerr; } /* * Calculate destination address based on kernel entrypoint */ dest = (vm_offset_t) ehdr.e_entry; if (dest == 0) { printf("elf_loadmodule: not a kernel (maybe static binary?)\n"); err = EPERM; goto oerr; } kernel = 1; addr = dest; } else { err = EFTYPE; goto oerr; } /* * Ok, we think we should handle this. */ mp = mod_allocmodule(); if (kernel) mp->m_name = strdup(filename); /* XXX should we prune the name? */ mp->m_type = strdup(kernel ? elf_kerneltype : elf_moduletype); printf("%s at %p\n", filename, (void *) addr); mp->m_size = elf_loadimage(mp, fd, &addr, &ehdr, kernel); if (mp->m_size == 0) goto ioerr; mp->m_addr = addr; /* save the aligned load address */ #if 0 /* Handle KLD module data */ if (!kernel && ((err = elf_fixupkldmod(mp, &ehdr)) != 0)) goto oerr; #endif /* save exec header as metadata */ mod_addmetadata(mp, MODINFOMD_ELFHDR, sizeof(ehdr), &ehdr); /* Load OK, return module pointer */ *result = (struct loaded_module *)mp; err = 0; goto out; ioerr: err = EIO; oerr: mod_discard(mp); out: close(fd); return(err); } /* * With the file (fd) open on the image, and (ehdr) containing * the Elf header, load the image at (addr) */ static int elf_loadimage(struct loaded_module *mp, int fd, vm_offset_t *addr, Elf_Ehdr *ehdr, int kernel) { int i, j; Elf_Phdr *phdr; Elf_Shdr *shdr; Elf_Ehdr local_ehdr; int ret; vm_offset_t firstaddr; vm_offset_t lastaddr; vm_offset_t off; void *buf; size_t resid, chunk; vm_offset_t dest; char *secname; vm_offset_t shdrpos; vm_offset_t ssym, esym; ret = 0; firstaddr = lastaddr = 0; if (kernel) #ifdef __i386__ off = 0x10000000; /* -0xf0000000 - i386 relocates after locore */ #else off = 0; /* alpha is direct mapped for kernels */ #endif else off = *addr; /* load relative to passed address */ phdr = malloc(ehdr->e_phnum * sizeof(*phdr)); if (phdr == NULL) goto out; if (lseek(fd, ehdr->e_phoff, SEEK_SET) == -1) { printf("elf_loadexec: lseek for phdr failed\n"); goto out; } if (read(fd, phdr, ehdr->e_phnum * sizeof(*phdr)) != ehdr->e_phnum * sizeof(*phdr)) { printf("elf_loadexec: cannot read program header\n"); goto out; } for (i = 0; i < ehdr->e_phnum; i++) { /* We want to load PT_LOAD segments only.. */ if (phdr[i].p_type != PT_LOAD) continue; printf("Segment: 0x%lx@0x%lx -> 0x%lx-0x%lx", (long)phdr[i].p_filesz, (long)phdr[i].p_offset, (long)(phdr[i].p_vaddr + off), (long)(phdr[i].p_vaddr + off + phdr[i].p_memsz - 1)); if (lseek(fd, phdr[i].p_offset, SEEK_SET) == -1) { printf("\nelf_loadexec: cannot seek\n"); goto out; } if (archsw.arch_readin(fd, phdr[i].p_vaddr + off, phdr[i].p_filesz) != phdr[i].p_filesz) { printf("\nelf_loadexec: archsw.readin failed\n"); goto out; } /* clear space from oversized segments; eg: bss */ if (phdr[i].p_filesz < phdr[i].p_memsz) { printf(" (bss: 0x%lx-0x%lx)", (long)(phdr[i].p_vaddr + off + phdr[i].p_filesz), (long)(phdr[i].p_vaddr + off + phdr[i].p_memsz - 1)); /* no archsw.arch_bzero */ buf = malloc(PAGE_SIZE); bzero(buf, PAGE_SIZE); resid = phdr[i].p_memsz - phdr[i].p_filesz; dest = phdr[i].p_vaddr + off + phdr[i].p_filesz; while (resid > 0) { chunk = min(PAGE_SIZE, resid); archsw.arch_copyin(buf, dest, chunk); resid -= chunk; dest += chunk; } free(buf); } printf("\n"); if (firstaddr < (phdr[i].p_vaddr + off)) firstaddr = phdr[i].p_vaddr + off; if (lastaddr < (phdr[i].p_vaddr + off + phdr[i].p_memsz)) lastaddr = phdr[i].p_vaddr + off + phdr[i].p_memsz; } /* * Now grab the symbol tables. This isn't easy if we're reading a * .gz file. I think the rule is going to have to be that you must * strip a file to remove symbols before gzipping it so that we do not * try to lseek() on it. The layout is a bit wierd, but it's what * the NetBSD-derived ddb/db_elf.c wants. */ lastaddr = roundup(lastaddr, sizeof(long)); chunk = ehdr->e_shnum * ehdr->e_shentsize; shdr = malloc(chunk); if (shdr == NULL) goto nosyms; ssym = lastaddr; printf("Symbols: ELF Ehdr @ 0x%x; ", lastaddr); lastaddr += sizeof(*ehdr); lastaddr = roundup(lastaddr, sizeof(long)); /* Copy out executable header modified for base offsets */ local_ehdr = *ehdr; local_ehdr.e_phoff = 0; local_ehdr.e_phentsize = 0; local_ehdr.e_phnum = 0; local_ehdr.e_shoff = lastaddr - ssym; archsw.arch_copyin(&local_ehdr, ssym, sizeof(*ehdr)); if (lseek(fd, ehdr->e_shoff, SEEK_SET) == -1) { printf("elf_loadimage: cannot lseek() to section headers\n"); lastaddr = ssym; /* wind back */ ssym = 0; goto nosyms; } if (read(fd, shdr, chunk) != chunk) { printf("elf_loadimage: read section headers failed\n"); lastaddr = ssym; /* wind back */ ssym = 0; goto nosyms; } shdrpos = lastaddr; printf("Section table: 0x%x@0x%x\n", chunk, shdrpos); lastaddr += chunk; lastaddr = roundup(lastaddr, sizeof(long)); for (i = 0; i < ehdr->e_shnum; i++) { switch(shdr[i].sh_type) { /* * These are the symbol tables. Their names are relative to * an arbitary string table. */ case SHT_SYMTAB: /* Symbol table */ secname = "symtab"; break; case SHT_DYNSYM: /* Dynamic linking symbol table */ secname = "dynsym"; break; /* * And here are the string tables. These can be referred to from * a number of sources, including the dynsym, the section table * names itself, etc. */ case SHT_STRTAB: /* String table */ secname = "strtab"; break; default: /* Skip it */ continue; } for (j = 0; j < ehdr->e_phnum; j++) { if (phdr[j].p_type != PT_LOAD) continue; if (shdr[i].sh_offset >= phdr[j].p_offset && (shdr[i].sh_offset + shdr[i].sh_size <= phdr[j].p_offset + phdr[j].p_filesz)) { shdr[i].sh_offset = 0; shdr[i].sh_size = 0; break; } } if (shdr[i].sh_offset == 0 || shdr[i].sh_size == 0) continue; /* alread loaded in a PT_LOAD above */ printf("%s: 0x%x@0x%x -> 0x%x-0x%x\n", secname, shdr[i].sh_size, shdr[i].sh_offset, lastaddr, lastaddr + shdr[i].sh_size); if (lseek(fd, shdr[i].sh_offset, SEEK_SET) == -1) { printf("\nelf_loadimage: could not seek for symbols - skipped!\n"); shdr[i].sh_offset = 0; shdr[i].sh_size = 0; continue; } if (archsw.arch_readin(fd, lastaddr, shdr[i].sh_size) != shdr[i].sh_size) { printf("\nelf_loadimage: could not read symbols - skipped!\n"); shdr[i].sh_offset = 0; shdr[i].sh_size = 0; continue; } /* Reset offsets relative to ssym */ shdr[i].sh_offset = lastaddr - ssym; lastaddr += shdr[i].sh_size; lastaddr = roundup(lastaddr, sizeof(long)); } archsw.arch_copyin(shdr, lastaddr, sizeof(*ehdr)); esym = lastaddr; mod_addmetadata(mp, MODINFOMD_ELFSSYM, sizeof(ssym), &ssym); mod_addmetadata(mp, MODINFOMD_ELFESYM, sizeof(esym), &esym); nosyms: ret = lastaddr - firstaddr; *addr = firstaddr; out: if (phdr) free(phdr); return ret; }