/*- * 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. */ #include __FBSDID("$FreeBSD$"); #include #include #include #include #include #include #include #define FREEBSD_ELF #include #include "bootstrap.h" #define COPYOUT(s,d,l) archsw.arch_copyout((vm_offset_t)(s), d, l) #if defined(__i386__) && __ELF_WORD_SIZE == 64 #undef ELF_TARG_CLASS #undef ELF_TARG_MACH #define ELF_TARG_CLASS ELFCLASS64 #define ELF_TARG_MACH EM_X86_64 #endif typedef struct elf_file { Elf_Phdr *ph; Elf_Ehdr *ehdr; Elf_Sym *symtab; Elf_Hashelt *hashtab; Elf_Hashelt nbuckets; Elf_Hashelt nchains; Elf_Hashelt *buckets; Elf_Hashelt *chains; Elf_Rel *rel; size_t relsz; Elf_Rela *rela; size_t relasz; char *strtab; size_t strsz; int fd; caddr_t firstpage; size_t firstlen; int kernel; u_int64_t off; } *elf_file_t; static int __elfN(loadimage)(struct preloaded_file *mp, elf_file_t ef, u_int64_t loadaddr); static int __elfN(lookup_symbol)(struct preloaded_file *mp, elf_file_t ef, const char* name, Elf_Sym* sym); static int __elfN(reloc_ptr)(struct preloaded_file *mp, elf_file_t ef, Elf_Addr p, void *val, size_t len); static int __elfN(parse_modmetadata)(struct preloaded_file *mp, elf_file_t ef); static symaddr_fn __elfN(symaddr); static char *fake_modname(const char *name); const char *__elfN(kerneltype) = "elf kernel"; const char *__elfN(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 __elfN(loadfile)(char *filename, u_int64_t dest, struct preloaded_file **result) { struct preloaded_file *fp, *kfp; struct elf_file ef; Elf_Ehdr *ehdr; int err; u_int pad; ssize_t bytes_read; fp = NULL; bzero(&ef, sizeof(struct elf_file)); /* * Open the image, read and validate the ELF header */ if (filename == NULL) /* can't handle nameless */ return(EFTYPE); if ((ef.fd = open(filename, O_RDONLY)) == -1) return(errno); ef.firstpage = malloc(PAGE_SIZE); if (ef.firstpage == NULL) { close(ef.fd); return(ENOMEM); } bytes_read = read(ef.fd, ef.firstpage, PAGE_SIZE); ef.firstlen = (size_t)bytes_read; if (bytes_read < 0 || ef.firstlen <= sizeof(Elf_Ehdr)) { err = EFTYPE; /* could be EIO, but may be small file */ goto oerr; } ehdr = ef.ehdr = (Elf_Ehdr *)ef.firstpage; /* 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. */ kfp = file_findfile(NULL, NULL); if (ehdr->e_type == ET_DYN) { /* Looks like a kld module */ if (kfp == NULL) { printf("elf" __XSTRING(__ELF_WORD_SIZE) "_loadfile: can't load module before kernel\n"); err = EPERM; goto oerr; } if (strcmp(__elfN(kerneltype), kfp->f_type)) { printf("elf" __XSTRING(__ELF_WORD_SIZE) "_loadfile: can't load module with kernel type '%s'\n", kfp->f_type); err = EPERM; goto oerr; } /* Looks OK, got ahead */ ef.kernel = 0; /* Page-align the load address */ pad = (u_int)dest & PAGE_MASK; if (pad != 0) { pad = PAGE_SIZE - pad; dest += pad; } } else if (ehdr->e_type == ET_EXEC) { /* Looks like a kernel */ if (kfp != NULL) { printf("elf" __XSTRING(__ELF_WORD_SIZE) "_loadfile: kernel already loaded\n"); err = EPERM; goto oerr; } /* * Calculate destination address based on kernel entrypoint */ dest = ehdr->e_entry; if (dest == 0) { printf("elf" __XSTRING(__ELF_WORD_SIZE) "_loadfile: not a kernel (maybe static binary?)\n"); err = EPERM; goto oerr; } ef.kernel = 1; } else { err = EFTYPE; goto oerr; } /* * Ok, we think we should handle this. */ fp = file_alloc(); if (fp == NULL) { printf("elf" __XSTRING(__ELF_WORD_SIZE) "_loadfile: cannot allocate module info\n"); err = EPERM; goto out; } if (ef.kernel) setenv("kernelname", filename, 1); fp->f_name = strdup(filename); fp->f_type = strdup(ef.kernel ? __elfN(kerneltype) : __elfN(moduletype)); #ifdef ELF_VERBOSE if (ef.kernel) printf("%s entry at 0x%jx\n", filename, (uintmax_t)dest); #else printf("%s ", filename); #endif fp->f_size = __elfN(loadimage)(fp, &ef, dest); if (fp->f_size == 0 || fp->f_addr == 0) goto ioerr; /* save exec header as metadata */ file_addmetadata(fp, MODINFOMD_ELFHDR, sizeof(*ehdr), ehdr); /* Load OK, return module pointer */ *result = (struct preloaded_file *)fp; err = 0; goto out; ioerr: err = EIO; oerr: file_discard(fp); out: if (ef.firstpage) free(ef.firstpage); close(ef.fd); return(err); } /* * With the file (fd) open on the image, and (ehdr) containing * the Elf header, load the image at (off) */ static int __elfN(loadimage)(struct preloaded_file *fp, elf_file_t ef, u_int64_t off) { int i; u_int j; Elf_Ehdr *ehdr; Elf_Phdr *phdr, *php; Elf_Shdr *shdr; int ret; vm_offset_t firstaddr; vm_offset_t lastaddr; size_t chunk; ssize_t result; Elf_Addr ssym, esym; Elf_Dyn *dp; Elf_Addr adp; int ndp; int symstrindex; int symtabindex; Elf_Size size; u_int fpcopy; dp = NULL; shdr = NULL; ret = 0; firstaddr = lastaddr = 0; ehdr = ef->ehdr; if (ef->kernel) { #ifdef __i386__ #if __ELF_WORD_SIZE == 64 off = - (off & 0xffffffffff000000ull);/* x86_64 relocates after locore */ #else off = - (off & 0xff000000u); /* i386 relocates after locore */ #endif #else off = 0; /* alpha is direct mapped for kernels */ #endif } ef->off = off; if ((ehdr->e_phoff + ehdr->e_phnum * sizeof(*phdr)) > ef->firstlen) { printf("elf" __XSTRING(__ELF_WORD_SIZE) "_loadimage: program header not within first page\n"); goto out; } phdr = (Elf_Phdr *)(ef->firstpage + ehdr->e_phoff); for (i = 0; i < ehdr->e_phnum; i++) { /* We want to load PT_LOAD segments only.. */ if (phdr[i].p_type != PT_LOAD) continue; #ifdef ELF_VERBOSE 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)); #else if ((phdr[i].p_flags & PF_W) == 0) { printf("text=0x%lx ", (long)phdr[i].p_filesz); } else { printf("data=0x%lx", (long)phdr[i].p_filesz); if (phdr[i].p_filesz < phdr[i].p_memsz) printf("+0x%lx", (long)(phdr[i].p_memsz -phdr[i].p_filesz)); printf(" "); } #endif fpcopy = 0; if (ef->firstlen > phdr[i].p_offset) { fpcopy = ef->firstlen - phdr[i].p_offset; archsw.arch_copyin(ef->firstpage + phdr[i].p_offset, phdr[i].p_vaddr + off, fpcopy); } if (phdr[i].p_filesz > fpcopy) { if (kern_pread(ef->fd, phdr[i].p_vaddr + off + fpcopy, phdr[i].p_filesz - fpcopy, phdr[i].p_offset + fpcopy) != 0) { printf("\nelf" __XSTRING(__ELF_WORD_SIZE) "_loadimage: read failed\n"); goto out; } } /* clear space from oversized segments; eg: bss */ if (phdr[i].p_filesz < phdr[i].p_memsz) { #ifdef ELF_VERBOSE 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)); #endif kern_bzero(phdr[i].p_vaddr + off + phdr[i].p_filesz, phdr[i].p_memsz - phdr[i].p_filesz); } #ifdef ELF_VERBOSE printf("\n"); #endif if (firstaddr == 0 || firstaddr > (phdr[i].p_vaddr + off)) firstaddr = phdr[i].p_vaddr + off; if (lastaddr == 0 || lastaddr < (phdr[i].p_vaddr + off + phdr[i].p_memsz)) lastaddr = phdr[i].p_vaddr + off + phdr[i].p_memsz; } lastaddr = roundup(lastaddr, sizeof(long)); /* * 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. */ chunk = ehdr->e_shnum * ehdr->e_shentsize; if (chunk == 0 || ehdr->e_shoff == 0) goto nosyms; shdr = alloc_pread(ef->fd, ehdr->e_shoff, chunk); if (shdr == NULL) { printf("\nelf" __XSTRING(__ELF_WORD_SIZE) "_loadimage: failed to read section headers"); goto nosyms; } symtabindex = -1; symstrindex = -1; for (i = 0; i < ehdr->e_shnum; i++) { if (shdr[i].sh_type != SHT_SYMTAB) 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 */ /* Save it for loading below */ symtabindex = i; symstrindex = shdr[i].sh_link; } if (symtabindex < 0 || symstrindex < 0) goto nosyms; /* Ok, committed to a load. */ #ifndef ELF_VERBOSE printf("syms=["); #endif ssym = lastaddr; for (i = symtabindex; i >= 0; i = symstrindex) { #ifdef ELF_VERBOSE char *secname; switch(shdr[i].sh_type) { case SHT_SYMTAB: /* Symbol table */ secname = "symtab"; break; case SHT_STRTAB: /* String table */ secname = "strtab"; break; default: secname = "WHOA!!"; break; } #endif size = shdr[i].sh_size; archsw.arch_copyin(&size, lastaddr, sizeof(size)); lastaddr += sizeof(size); #ifdef ELF_VERBOSE printf("\n%s: 0x%lx@0x%lx -> 0x%lx-0x%lx", secname, shdr[i].sh_size, shdr[i].sh_offset, lastaddr, lastaddr + shdr[i].sh_size); #else if (i == symstrindex) printf("+"); printf("0x%lx+0x%lx", (long)sizeof(size), (long)size); #endif if (lseek(ef->fd, (off_t)shdr[i].sh_offset, SEEK_SET) == -1) { printf("\nelf" __XSTRING(__ELF_WORD_SIZE) "_loadimage: could not seek for symbols - skipped!"); lastaddr = ssym; ssym = 0; goto nosyms; } result = archsw.arch_readin(ef->fd, lastaddr, shdr[i].sh_size); if (result < 0 || (size_t)result != shdr[i].sh_size) { printf("\nelf" __XSTRING(__ELF_WORD_SIZE) "_loadimage: could not read symbols - skipped!"); lastaddr = ssym; ssym = 0; goto nosyms; } /* Reset offsets relative to ssym */ lastaddr += shdr[i].sh_size; lastaddr = roundup(lastaddr, sizeof(size)); if (i == symtabindex) symtabindex = -1; else if (i == symstrindex) symstrindex = -1; } esym = lastaddr; #ifndef ELF_VERBOSE printf("]"); #endif file_addmetadata(fp, MODINFOMD_SSYM, sizeof(ssym), &ssym); file_addmetadata(fp, MODINFOMD_ESYM, sizeof(esym), &esym); nosyms: printf("\n"); ret = lastaddr - firstaddr; fp->f_addr = firstaddr; php = NULL; for (i = 0; i < ehdr->e_phnum; i++) { if (phdr[i].p_type == PT_DYNAMIC) { php = phdr + i; adp = php->p_vaddr; file_addmetadata(fp, MODINFOMD_DYNAMIC, sizeof(adp), &adp); break; } } if (php == NULL) /* this is bad, we cannot get to symbols or _DYNAMIC */ goto out; ndp = php->p_filesz / sizeof(Elf_Dyn); if (ndp == 0) goto out; dp = malloc(php->p_filesz); if (dp == NULL) goto out; archsw.arch_copyout(php->p_vaddr + off, dp, php->p_filesz); ef->strsz = 0; for (i = 0; i < ndp; i++) { if (dp[i].d_tag == 0) break; switch (dp[i].d_tag) { case DT_HASH: ef->hashtab = (Elf_Hashelt*)(uintptr_t)(dp[i].d_un.d_ptr + off); break; case DT_STRTAB: ef->strtab = (char *)(uintptr_t)(dp[i].d_un.d_ptr + off); break; case DT_STRSZ: ef->strsz = dp[i].d_un.d_val; break; case DT_SYMTAB: ef->symtab = (Elf_Sym*)(uintptr_t)(dp[i].d_un.d_ptr + off); break; case DT_REL: ef->rel = (Elf_Rel *)(uintptr_t)(dp[i].d_un.d_ptr + off); break; case DT_RELSZ: ef->relsz = dp[i].d_un.d_val; break; case DT_RELA: ef->rela = (Elf_Rela *)(uintptr_t)(dp[i].d_un.d_ptr + off); break; case DT_RELASZ: ef->relasz = dp[i].d_un.d_val; break; default: break; } } if (ef->hashtab == NULL || ef->symtab == NULL || ef->strtab == NULL || ef->strsz == 0) goto out; COPYOUT(ef->hashtab, &ef->nbuckets, sizeof(ef->nbuckets)); COPYOUT(ef->hashtab + 1, &ef->nchains, sizeof(ef->nchains)); ef->buckets = ef->hashtab + 2; ef->chains = ef->buckets + ef->nbuckets; if (__elfN(parse_modmetadata)(fp, ef) == 0) goto out; if (ef->kernel) /* kernel must not depend on anything */ goto out; out: if (dp) free(dp); if (shdr) free(shdr); return ret; } static char invalid_name[] = "bad"; char * fake_modname(const char *name) { const char *sp, *ep; char *fp; size_t len; sp = strrchr(name, '/'); if (sp) sp++; else sp = name; ep = strrchr(name, '.'); if (ep) { if (ep == name) { sp = invalid_name; ep = invalid_name + sizeof(invalid_name) - 1; } } else ep = name + strlen(name); len = ep - sp; fp = malloc(len + 1); if (fp == NULL) return NULL; memcpy(fp, sp, len); fp[len] = '\0'; return fp; } #if defined(__i386__) && __ELF_WORD_SIZE == 64 struct mod_metadata64 { int md_version; /* structure version MDTV_* */ int md_type; /* type of entry MDT_* */ u_int64_t md_data; /* specific data */ u_int64_t md_cval; /* common string label */ }; #endif int __elfN(parse_modmetadata)(struct preloaded_file *fp, elf_file_t ef) { struct mod_metadata md; #if defined(__i386__) && __ELF_WORD_SIZE == 64 struct mod_metadata64 md64; #endif struct mod_depend *mdepend; struct mod_version mver; Elf_Sym sym; char *s; int error, modcnt, minfolen; Elf_Addr v, p, p_stop; if (__elfN(lookup_symbol)(fp, ef, "__start_set_modmetadata_set", &sym) != 0) return ENOENT; p = sym.st_value + ef->off; if (__elfN(lookup_symbol)(fp, ef, "__stop_set_modmetadata_set", &sym) != 0) return ENOENT; p_stop = sym.st_value + ef->off; modcnt = 0; while (p < p_stop) { COPYOUT(p, &v, sizeof(v)); error = __elfN(reloc_ptr)(fp, ef, p, &v, sizeof(v)); if (error == EOPNOTSUPP) v += ef->off; else if (error != 0) return (error); #if defined(__i386__) && __ELF_WORD_SIZE == 64 COPYOUT(v, &md64, sizeof(md64)); error = __elfN(reloc_ptr)(fp, ef, v, &md64, sizeof(md64)); if (error == EOPNOTSUPP) { md64.md_cval += ef->off; md64.md_data += ef->off; } else if (error != 0) return (error); md.md_version = md64.md_version; md.md_type = md64.md_type; md.md_cval = (const char *)(uintptr_t)md64.md_cval; md.md_data = (void *)(uintptr_t)md64.md_data; #else COPYOUT(v, &md, sizeof(md)); error = __elfN(reloc_ptr)(fp, ef, v, &md, sizeof(md)); if (error == EOPNOTSUPP) { md.md_cval += ef->off; md.md_data += ef->off; } else if (error != 0) return (error); #endif p += sizeof(Elf_Addr); switch(md.md_type) { case MDT_DEPEND: if (ef->kernel) /* kernel must not depend on anything */ break; s = strdupout((vm_offset_t)md.md_cval); minfolen = sizeof(*mdepend) + strlen(s) + 1; mdepend = malloc(minfolen); if (mdepend == NULL) return ENOMEM; COPYOUT((vm_offset_t)md.md_data, mdepend, sizeof(*mdepend)); strcpy((char*)(mdepend + 1), s); free(s); file_addmetadata(fp, MODINFOMD_DEPLIST, minfolen, mdepend); free(mdepend); break; case MDT_VERSION: s = strdupout((vm_offset_t)md.md_cval); COPYOUT((vm_offset_t)md.md_data, &mver, sizeof(mver)); file_addmodule(fp, s, mver.mv_version, NULL); free(s); modcnt++; break; } } if (modcnt == 0) { s = fake_modname(fp->f_name); file_addmodule(fp, s, 1, NULL); free(s); } return 0; } static unsigned long elf_hash(const char *name) { const unsigned char *p = (const unsigned char *) name; unsigned long h = 0; unsigned long g; while (*p != '\0') { h = (h << 4) + *p++; if ((g = h & 0xf0000000) != 0) h ^= g >> 24; h &= ~g; } return h; } static const char __elfN(bad_symtable)[] = "elf" __XSTRING(__ELF_WORD_SIZE) "_lookup_symbol: corrupt symbol table\n"; int __elfN(lookup_symbol)(struct preloaded_file *fp, elf_file_t ef, const char* name, Elf_Sym *symp) { Elf_Hashelt symnum; Elf_Sym sym; char *strp; unsigned long hash; hash = elf_hash(name); COPYOUT(&ef->buckets[hash % ef->nbuckets], &symnum, sizeof(symnum)); while (symnum != STN_UNDEF) { if (symnum >= ef->nchains) { printf(__elfN(bad_symtable)); return ENOENT; } COPYOUT(ef->symtab + symnum, &sym, sizeof(sym)); if (sym.st_name == 0) { printf(__elfN(bad_symtable)); return ENOENT; } strp = strdupout((vm_offset_t)(ef->strtab + sym.st_name)); if (strcmp(name, strp) == 0) { free(strp); if (sym.st_shndx != SHN_UNDEF || (sym.st_value != 0 && ELF_ST_TYPE(sym.st_info) == STT_FUNC)) { *symp = sym; return 0; } return ENOENT; } free(strp); COPYOUT(&ef->chains[symnum], &symnum, sizeof(symnum)); } return ENOENT; } /* * Apply any intra-module relocations to the value. p is the load address * of the value and val/len is the value to be modified. This does NOT modify * the image in-place, because this is done by kern_linker later on. * * Returns EOPNOTSUPP if no relocation method is supplied. */ static int __elfN(reloc_ptr)(struct preloaded_file *mp, elf_file_t ef, Elf_Addr p, void *val, size_t len) { size_t n; Elf_Rela a; Elf_Rel r; int error; /* * The kernel is already relocated, but we still want to apply * offset adjustments. */ if (ef->kernel) return (EOPNOTSUPP); for (n = 0; n < ef->relsz / sizeof(r); n++) { COPYOUT(ef->rel + n, &r, sizeof(r)); error = __elfN(reloc)(ef, __elfN(symaddr), &r, ELF_RELOC_REL, ef->off, p, val, len); if (error != 0) return (error); } for (n = 0; n < ef->relasz / sizeof(a); n++) { COPYOUT(ef->rela + n, &a, sizeof(a)); error = __elfN(reloc)(ef, __elfN(symaddr), &a, ELF_RELOC_RELA, ef->off, p, val, len); if (error != 0) return (error); } return (0); } static Elf_Addr __elfN(symaddr)(struct elf_file *ef, Elf_Size symidx) { /* Symbol lookup by index not required here. */ return (0); }