/*- * SPDX-License-Identifier: BSD-2-Clause-FreeBSD * * Copyright (c) 1998-2000 Doug Rabson * Copyright (c) 2004 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 "opt_ddb.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef DDB_CTF #include #endif #include "linker_if.h" typedef struct { void *addr; Elf_Off size; int flags; int sec; /* Original section */ char *name; } Elf_progent; typedef struct { Elf_Rel *rel; int nrel; int sec; } Elf_relent; typedef struct { Elf_Rela *rela; int nrela; int sec; } Elf_relaent; typedef struct elf_file { struct linker_file lf; /* Common fields */ int preloaded; caddr_t address; /* Relocation address */ vm_object_t object; /* VM object to hold file pages */ Elf_Shdr *e_shdr; Elf_progent *progtab; int nprogtab; Elf_relaent *relatab; int nrelatab; Elf_relent *reltab; int nreltab; Elf_Sym *ddbsymtab; /* The symbol table we are using */ long ddbsymcnt; /* Number of symbols */ caddr_t ddbstrtab; /* String table */ long ddbstrcnt; /* number of bytes in string table */ caddr_t shstrtab; /* Section name string table */ long shstrcnt; /* number of bytes in string table */ caddr_t ctftab; /* CTF table */ long ctfcnt; /* number of bytes in CTF table */ caddr_t ctfoff; /* CTF offset table */ caddr_t typoff; /* Type offset table */ long typlen; /* Number of type entries. */ } *elf_file_t; #include static int link_elf_link_preload(linker_class_t cls, const char *, linker_file_t *); static int link_elf_link_preload_finish(linker_file_t); static int link_elf_load_file(linker_class_t, const char *, linker_file_t *); static int link_elf_lookup_symbol(linker_file_t, const char *, c_linker_sym_t *); static int link_elf_symbol_values(linker_file_t, c_linker_sym_t, linker_symval_t *); static int link_elf_search_symbol(linker_file_t, caddr_t value, c_linker_sym_t *sym, long *diffp); static void link_elf_unload_file(linker_file_t); static int link_elf_lookup_set(linker_file_t, const char *, void ***, void ***, int *); static int link_elf_each_function_name(linker_file_t, int (*)(const char *, void *), void *); static int link_elf_each_function_nameval(linker_file_t, linker_function_nameval_callback_t, void *); static int link_elf_reloc_local(linker_file_t); static long link_elf_symtab_get(linker_file_t, const Elf_Sym **); static long link_elf_strtab_get(linker_file_t, caddr_t *); static int elf_obj_lookup(linker_file_t lf, Elf_Size symidx, int deps, Elf_Addr *); static kobj_method_t link_elf_methods[] = { KOBJMETHOD(linker_lookup_symbol, link_elf_lookup_symbol), KOBJMETHOD(linker_symbol_values, link_elf_symbol_values), KOBJMETHOD(linker_search_symbol, link_elf_search_symbol), KOBJMETHOD(linker_unload, link_elf_unload_file), KOBJMETHOD(linker_load_file, link_elf_load_file), KOBJMETHOD(linker_link_preload, link_elf_link_preload), KOBJMETHOD(linker_link_preload_finish, link_elf_link_preload_finish), KOBJMETHOD(linker_lookup_set, link_elf_lookup_set), KOBJMETHOD(linker_each_function_name, link_elf_each_function_name), KOBJMETHOD(linker_each_function_nameval, link_elf_each_function_nameval), KOBJMETHOD(linker_ctf_get, link_elf_ctf_get), KOBJMETHOD(linker_symtab_get, link_elf_symtab_get), KOBJMETHOD(linker_strtab_get, link_elf_strtab_get), { 0, 0 } }; static struct linker_class link_elf_class = { #if ELF_TARG_CLASS == ELFCLASS32 "elf32_obj", #else "elf64_obj", #endif link_elf_methods, sizeof(struct elf_file) }; static int relocate_file(elf_file_t ef); static void elf_obj_cleanup_globals_cache(elf_file_t); static void link_elf_error(const char *filename, const char *s) { if (filename == NULL) printf("kldload: %s\n", s); else printf("kldload: %s: %s\n", filename, s); } static void link_elf_init(void *arg) { linker_add_class(&link_elf_class); } SYSINIT(link_elf_obj, SI_SUB_KLD, SI_ORDER_SECOND, link_elf_init, 0); static int link_elf_link_preload(linker_class_t cls, const char *filename, linker_file_t *result) { Elf_Ehdr *hdr; Elf_Shdr *shdr; Elf_Sym *es; void *modptr, *baseptr, *sizeptr; char *type; elf_file_t ef; linker_file_t lf; Elf_Addr off; int error, i, j, pb, ra, rl, shstrindex, symstrindex, symtabindex; /* Look to see if we have the file preloaded */ modptr = preload_search_by_name(filename); if (modptr == NULL) return ENOENT; type = (char *)preload_search_info(modptr, MODINFO_TYPE); baseptr = preload_search_info(modptr, MODINFO_ADDR); sizeptr = preload_search_info(modptr, MODINFO_SIZE); hdr = (Elf_Ehdr *)preload_search_info(modptr, MODINFO_METADATA | MODINFOMD_ELFHDR); shdr = (Elf_Shdr *)preload_search_info(modptr, MODINFO_METADATA | MODINFOMD_SHDR); if (type == NULL || (strcmp(type, "elf" __XSTRING(__ELF_WORD_SIZE) " obj module") != 0 && strcmp(type, "elf obj module") != 0)) { return (EFTYPE); } if (baseptr == NULL || sizeptr == NULL || hdr == NULL || shdr == NULL) return (EINVAL); lf = linker_make_file(filename, &link_elf_class); if (lf == NULL) return (ENOMEM); ef = (elf_file_t)lf; ef->preloaded = 1; ef->address = *(caddr_t *)baseptr; lf->address = *(caddr_t *)baseptr; lf->size = *(size_t *)sizeptr; if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS || hdr->e_ident[EI_DATA] != ELF_TARG_DATA || hdr->e_ident[EI_VERSION] != EV_CURRENT || hdr->e_version != EV_CURRENT || hdr->e_type != ET_REL || hdr->e_machine != ELF_TARG_MACH) { error = EFTYPE; goto out; } ef->e_shdr = shdr; /* Scan the section header for information and table sizing. */ symtabindex = -1; symstrindex = -1; for (i = 0; i < hdr->e_shnum; i++) { switch (shdr[i].sh_type) { case SHT_PROGBITS: case SHT_NOBITS: #ifdef __amd64__ case SHT_X86_64_UNWIND: #endif /* Ignore sections not loaded by the loader. */ if (shdr[i].sh_addr == 0) break; ef->nprogtab++; break; case SHT_SYMTAB: symtabindex = i; symstrindex = shdr[i].sh_link; break; case SHT_REL: ef->nreltab++; break; case SHT_RELA: ef->nrelatab++; break; } } shstrindex = hdr->e_shstrndx; if (ef->nprogtab == 0 || symstrindex < 0 || symstrindex >= hdr->e_shnum || shdr[symstrindex].sh_type != SHT_STRTAB || shstrindex == 0 || shstrindex >= hdr->e_shnum || shdr[shstrindex].sh_type != SHT_STRTAB) { printf("%s: bad/missing section headers\n", filename); error = ENOEXEC; goto out; } /* Allocate space for tracking the load chunks */ if (ef->nprogtab != 0) ef->progtab = malloc(ef->nprogtab * sizeof(*ef->progtab), M_LINKER, M_WAITOK | M_ZERO); if (ef->nreltab != 0) ef->reltab = malloc(ef->nreltab * sizeof(*ef->reltab), M_LINKER, M_WAITOK | M_ZERO); if (ef->nrelatab != 0) ef->relatab = malloc(ef->nrelatab * sizeof(*ef->relatab), M_LINKER, M_WAITOK | M_ZERO); if ((ef->nprogtab != 0 && ef->progtab == NULL) || (ef->nreltab != 0 && ef->reltab == NULL) || (ef->nrelatab != 0 && ef->relatab == NULL)) { error = ENOMEM; goto out; } /* XXX, relocate the sh_addr fields saved by the loader. */ off = 0; for (i = 0; i < hdr->e_shnum; i++) { if (shdr[i].sh_addr != 0 && (off == 0 || shdr[i].sh_addr < off)) off = shdr[i].sh_addr; } for (i = 0; i < hdr->e_shnum; i++) { if (shdr[i].sh_addr != 0) shdr[i].sh_addr = shdr[i].sh_addr - off + (Elf_Addr)ef->address; } ef->ddbsymcnt = shdr[symtabindex].sh_size / sizeof(Elf_Sym); ef->ddbsymtab = (Elf_Sym *)shdr[symtabindex].sh_addr; ef->ddbstrcnt = shdr[symstrindex].sh_size; ef->ddbstrtab = (char *)shdr[symstrindex].sh_addr; ef->shstrcnt = shdr[shstrindex].sh_size; ef->shstrtab = (char *)shdr[shstrindex].sh_addr; /* Now fill out progtab and the relocation tables. */ pb = 0; rl = 0; ra = 0; for (i = 0; i < hdr->e_shnum; i++) { switch (shdr[i].sh_type) { case SHT_PROGBITS: case SHT_NOBITS: #ifdef __amd64__ case SHT_X86_64_UNWIND: #endif if (shdr[i].sh_addr == 0) break; ef->progtab[pb].addr = (void *)shdr[i].sh_addr; if (shdr[i].sh_type == SHT_PROGBITS) ef->progtab[pb].name = "<>"; #ifdef __amd64__ else if (shdr[i].sh_type == SHT_X86_64_UNWIND) ef->progtab[pb].name = "<>"; #endif else ef->progtab[pb].name = "<>"; ef->progtab[pb].size = shdr[i].sh_size; ef->progtab[pb].sec = i; if (ef->shstrtab && shdr[i].sh_name != 0) ef->progtab[pb].name = ef->shstrtab + shdr[i].sh_name; if (ef->progtab[pb].name != NULL && !strcmp(ef->progtab[pb].name, DPCPU_SETNAME)) { void *dpcpu; dpcpu = dpcpu_alloc(shdr[i].sh_size); if (dpcpu == NULL) { error = ENOSPC; goto out; } memcpy(dpcpu, ef->progtab[pb].addr, ef->progtab[pb].size); dpcpu_copy(dpcpu, shdr[i].sh_size); ef->progtab[pb].addr = dpcpu; #ifdef VIMAGE } else if (ef->progtab[pb].name != NULL && !strcmp(ef->progtab[pb].name, VNET_SETNAME)) { void *vnet_data; vnet_data = vnet_data_alloc(shdr[i].sh_size); if (vnet_data == NULL) { error = ENOSPC; goto out; } memcpy(vnet_data, ef->progtab[pb].addr, ef->progtab[pb].size); vnet_data_copy(vnet_data, shdr[i].sh_size); ef->progtab[pb].addr = vnet_data; #endif } else if (ef->progtab[pb].name != NULL && !strcmp(ef->progtab[pb].name, ".ctors")) { lf->ctors_addr = ef->progtab[pb].addr; lf->ctors_size = shdr[i].sh_size; } /* Update all symbol values with the offset. */ for (j = 0; j < ef->ddbsymcnt; j++) { es = &ef->ddbsymtab[j]; if (es->st_shndx != i) continue; es->st_value += (Elf_Addr)ef->progtab[pb].addr; } pb++; break; case SHT_REL: ef->reltab[rl].rel = (Elf_Rel *)shdr[i].sh_addr; ef->reltab[rl].nrel = shdr[i].sh_size / sizeof(Elf_Rel); ef->reltab[rl].sec = shdr[i].sh_info; rl++; break; case SHT_RELA: ef->relatab[ra].rela = (Elf_Rela *)shdr[i].sh_addr; ef->relatab[ra].nrela = shdr[i].sh_size / sizeof(Elf_Rela); ef->relatab[ra].sec = shdr[i].sh_info; ra++; break; } } if (pb != ef->nprogtab) { printf("%s: lost progbits\n", filename); error = ENOEXEC; goto out; } if (rl != ef->nreltab) { printf("%s: lost reltab\n", filename); error = ENOEXEC; goto out; } if (ra != ef->nrelatab) { printf("%s: lost relatab\n", filename); error = ENOEXEC; goto out; } /* Local intra-module relocations */ error = link_elf_reloc_local(lf); if (error != 0) goto out; *result = lf; return (0); out: /* preload not done this way */ linker_file_unload(lf, LINKER_UNLOAD_FORCE); return (error); } static void link_elf_invoke_ctors(caddr_t addr, size_t size) { void (**ctor)(void); size_t i, cnt; if (addr == NULL || size == 0) return; cnt = size / sizeof(*ctor); ctor = (void *)addr; for (i = 0; i < cnt; i++) { if (ctor[i] != NULL) (*ctor[i])(); } } static int link_elf_link_preload_finish(linker_file_t lf) { elf_file_t ef; int error; ef = (elf_file_t)lf; error = relocate_file(ef); if (error) return error; /* Notify MD code that a module is being loaded. */ error = elf_cpu_load_file(lf); if (error) return (error); /* Invoke .ctors */ link_elf_invoke_ctors(lf->ctors_addr, lf->ctors_size); return (0); } static int link_elf_load_file(linker_class_t cls, const char *filename, linker_file_t *result) { struct nameidata *nd; struct thread *td = curthread; /* XXX */ Elf_Ehdr *hdr; Elf_Shdr *shdr; Elf_Sym *es; int nbytes, i, j; vm_offset_t mapbase; size_t mapsize; int error = 0; ssize_t resid; int flags; elf_file_t ef; linker_file_t lf; int symtabindex; int symstrindex; int shstrindex; int nsym; int pb, rl, ra; int alignmask; shdr = NULL; lf = NULL; mapsize = 0; hdr = NULL; nd = malloc(sizeof(struct nameidata), M_TEMP, M_WAITOK); NDINIT(nd, LOOKUP, FOLLOW, UIO_SYSSPACE, filename, td); flags = FREAD; error = vn_open(nd, &flags, 0, NULL); if (error) { free(nd, M_TEMP); return error; } NDFREE(nd, NDF_ONLY_PNBUF); if (nd->ni_vp->v_type != VREG) { error = ENOEXEC; goto out; } #ifdef MAC error = mac_kld_check_load(td->td_ucred, nd->ni_vp); if (error) { goto out; } #endif /* Read the elf header from the file. */ hdr = malloc(sizeof(*hdr), M_LINKER, M_WAITOK); error = vn_rdwr(UIO_READ, nd->ni_vp, (void *)hdr, sizeof(*hdr), 0, UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, &resid, td); if (error) goto out; if (resid != 0){ error = ENOEXEC; goto out; } if (!IS_ELF(*hdr)) { error = ENOEXEC; goto out; } if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS || hdr->e_ident[EI_DATA] != ELF_TARG_DATA) { link_elf_error(filename, "Unsupported file layout"); error = ENOEXEC; goto out; } if (hdr->e_ident[EI_VERSION] != EV_CURRENT || hdr->e_version != EV_CURRENT) { link_elf_error(filename, "Unsupported file version"); error = ENOEXEC; goto out; } if (hdr->e_type != ET_REL) { error = ENOSYS; goto out; } if (hdr->e_machine != ELF_TARG_MACH) { link_elf_error(filename, "Unsupported machine"); error = ENOEXEC; goto out; } lf = linker_make_file(filename, &link_elf_class); if (!lf) { error = ENOMEM; goto out; } ef = (elf_file_t) lf; ef->nprogtab = 0; ef->e_shdr = 0; ef->nreltab = 0; ef->nrelatab = 0; /* Allocate and read in the section header */ nbytes = hdr->e_shnum * hdr->e_shentsize; if (nbytes == 0 || hdr->e_shoff == 0 || hdr->e_shentsize != sizeof(Elf_Shdr)) { error = ENOEXEC; goto out; } shdr = malloc(nbytes, M_LINKER, M_WAITOK); ef->e_shdr = shdr; error = vn_rdwr(UIO_READ, nd->ni_vp, (caddr_t)shdr, nbytes, hdr->e_shoff, UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, &resid, td); if (error) goto out; if (resid) { error = ENOEXEC; goto out; } /* Scan the section header for information and table sizing. */ nsym = 0; symtabindex = -1; symstrindex = -1; for (i = 0; i < hdr->e_shnum; i++) { if (shdr[i].sh_size == 0) continue; switch (shdr[i].sh_type) { case SHT_PROGBITS: case SHT_NOBITS: #ifdef __amd64__ case SHT_X86_64_UNWIND: #endif if ((shdr[i].sh_flags & SHF_ALLOC) == 0) break; ef->nprogtab++; break; case SHT_SYMTAB: nsym++; symtabindex = i; symstrindex = shdr[i].sh_link; break; case SHT_REL: ef->nreltab++; break; case SHT_RELA: ef->nrelatab++; break; case SHT_STRTAB: break; } } if (ef->nprogtab == 0) { link_elf_error(filename, "file has no contents"); error = ENOEXEC; goto out; } if (nsym != 1) { /* Only allow one symbol table for now */ link_elf_error(filename, "file has no valid symbol table"); error = ENOEXEC; goto out; } if (symstrindex < 0 || symstrindex > hdr->e_shnum || shdr[symstrindex].sh_type != SHT_STRTAB) { link_elf_error(filename, "file has invalid symbol strings"); error = ENOEXEC; goto out; } /* Allocate space for tracking the load chunks */ if (ef->nprogtab != 0) ef->progtab = malloc(ef->nprogtab * sizeof(*ef->progtab), M_LINKER, M_WAITOK | M_ZERO); if (ef->nreltab != 0) ef->reltab = malloc(ef->nreltab * sizeof(*ef->reltab), M_LINKER, M_WAITOK | M_ZERO); if (ef->nrelatab != 0) ef->relatab = malloc(ef->nrelatab * sizeof(*ef->relatab), M_LINKER, M_WAITOK | M_ZERO); if (symtabindex == -1) { link_elf_error(filename, "lost symbol table index"); error = ENOEXEC; goto out; } /* Allocate space for and load the symbol table */ ef->ddbsymcnt = shdr[symtabindex].sh_size / sizeof(Elf_Sym); ef->ddbsymtab = malloc(shdr[symtabindex].sh_size, M_LINKER, M_WAITOK); error = vn_rdwr(UIO_READ, nd->ni_vp, (void *)ef->ddbsymtab, shdr[symtabindex].sh_size, shdr[symtabindex].sh_offset, UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, &resid, td); if (error) goto out; if (resid != 0){ error = EINVAL; goto out; } if (symstrindex == -1) { link_elf_error(filename, "lost symbol string index"); error = ENOEXEC; goto out; } /* Allocate space for and load the symbol strings */ ef->ddbstrcnt = shdr[symstrindex].sh_size; ef->ddbstrtab = malloc(shdr[symstrindex].sh_size, M_LINKER, M_WAITOK); error = vn_rdwr(UIO_READ, nd->ni_vp, ef->ddbstrtab, shdr[symstrindex].sh_size, shdr[symstrindex].sh_offset, UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, &resid, td); if (error) goto out; if (resid != 0){ error = EINVAL; goto out; } /* Do we have a string table for the section names? */ shstrindex = -1; if (hdr->e_shstrndx != 0 && shdr[hdr->e_shstrndx].sh_type == SHT_STRTAB) { shstrindex = hdr->e_shstrndx; ef->shstrcnt = shdr[shstrindex].sh_size; ef->shstrtab = malloc(shdr[shstrindex].sh_size, M_LINKER, M_WAITOK); error = vn_rdwr(UIO_READ, nd->ni_vp, ef->shstrtab, shdr[shstrindex].sh_size, shdr[shstrindex].sh_offset, UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, &resid, td); if (error) goto out; if (resid != 0){ error = EINVAL; goto out; } } /* Size up code/data(progbits) and bss(nobits). */ alignmask = 0; for (i = 0; i < hdr->e_shnum; i++) { if (shdr[i].sh_size == 0) continue; switch (shdr[i].sh_type) { case SHT_PROGBITS: case SHT_NOBITS: #ifdef __amd64__ case SHT_X86_64_UNWIND: #endif if ((shdr[i].sh_flags & SHF_ALLOC) == 0) break; alignmask = shdr[i].sh_addralign - 1; mapsize += alignmask; mapsize &= ~alignmask; mapsize += shdr[i].sh_size; break; } } /* * We know how much space we need for the text/data/bss/etc. * This stuff needs to be in a single chunk so that profiling etc * can get the bounds and gdb can associate offsets with modules */ ef->object = vm_object_allocate(OBJT_DEFAULT, round_page(mapsize) >> PAGE_SHIFT); if (ef->object == NULL) { error = ENOMEM; goto out; } ef->address = (caddr_t) vm_map_min(kernel_map); /* * In order to satisfy amd64's architectural requirements on the * location of code and data in the kernel's address space, request a * mapping that is above the kernel. */ #ifdef __amd64__ mapbase = KERNBASE; #else mapbase = VM_MIN_KERNEL_ADDRESS; #endif error = vm_map_find(kernel_map, ef->object, 0, &mapbase, round_page(mapsize), 0, VMFS_OPTIMAL_SPACE, VM_PROT_ALL, VM_PROT_ALL, 0); if (error) { vm_object_deallocate(ef->object); ef->object = 0; goto out; } /* Wire the pages */ error = vm_map_wire(kernel_map, mapbase, mapbase + round_page(mapsize), VM_MAP_WIRE_SYSTEM|VM_MAP_WIRE_NOHOLES); if (error != KERN_SUCCESS) { error = ENOMEM; goto out; } /* Inform the kld system about the situation */ lf->address = ef->address = (caddr_t)mapbase; lf->size = mapsize; /* * Now load code/data(progbits), zero bss(nobits), allocate space for * and load relocs */ pb = 0; rl = 0; ra = 0; alignmask = 0; for (i = 0; i < hdr->e_shnum; i++) { if (shdr[i].sh_size == 0) continue; switch (shdr[i].sh_type) { case SHT_PROGBITS: case SHT_NOBITS: #ifdef __amd64__ case SHT_X86_64_UNWIND: #endif if ((shdr[i].sh_flags & SHF_ALLOC) == 0) break; alignmask = shdr[i].sh_addralign - 1; mapbase += alignmask; mapbase &= ~alignmask; if (ef->shstrtab != NULL && shdr[i].sh_name != 0) { ef->progtab[pb].name = ef->shstrtab + shdr[i].sh_name; if (!strcmp(ef->progtab[pb].name, ".ctors")) { lf->ctors_addr = (caddr_t)mapbase; lf->ctors_size = shdr[i].sh_size; } } else if (shdr[i].sh_type == SHT_PROGBITS) ef->progtab[pb].name = "<>"; #ifdef __amd64__ else if (shdr[i].sh_type == SHT_X86_64_UNWIND) ef->progtab[pb].name = "<>"; #endif else ef->progtab[pb].name = "<>"; if (ef->progtab[pb].name != NULL && !strcmp(ef->progtab[pb].name, DPCPU_SETNAME)) ef->progtab[pb].addr = dpcpu_alloc(shdr[i].sh_size); #ifdef VIMAGE else if (ef->progtab[pb].name != NULL && !strcmp(ef->progtab[pb].name, VNET_SETNAME)) ef->progtab[pb].addr = vnet_data_alloc(shdr[i].sh_size); #endif else ef->progtab[pb].addr = (void *)(uintptr_t)mapbase; if (ef->progtab[pb].addr == NULL) { error = ENOSPC; goto out; } ef->progtab[pb].size = shdr[i].sh_size; ef->progtab[pb].sec = i; if (shdr[i].sh_type == SHT_PROGBITS #ifdef __amd64__ || shdr[i].sh_type == SHT_X86_64_UNWIND #endif ) { error = vn_rdwr(UIO_READ, nd->ni_vp, ef->progtab[pb].addr, shdr[i].sh_size, shdr[i].sh_offset, UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, &resid, td); if (error) goto out; if (resid != 0){ error = EINVAL; goto out; } /* Initialize the per-cpu or vnet area. */ if (ef->progtab[pb].addr != (void *)mapbase && !strcmp(ef->progtab[pb].name, DPCPU_SETNAME)) dpcpu_copy(ef->progtab[pb].addr, shdr[i].sh_size); #ifdef VIMAGE else if (ef->progtab[pb].addr != (void *)mapbase && !strcmp(ef->progtab[pb].name, VNET_SETNAME)) vnet_data_copy(ef->progtab[pb].addr, shdr[i].sh_size); #endif } else bzero(ef->progtab[pb].addr, shdr[i].sh_size); /* Update all symbol values with the offset. */ for (j = 0; j < ef->ddbsymcnt; j++) { es = &ef->ddbsymtab[j]; if (es->st_shndx != i) continue; es->st_value += (Elf_Addr)ef->progtab[pb].addr; } mapbase += shdr[i].sh_size; pb++; break; case SHT_REL: ef->reltab[rl].rel = malloc(shdr[i].sh_size, M_LINKER, M_WAITOK); ef->reltab[rl].nrel = shdr[i].sh_size / sizeof(Elf_Rel); ef->reltab[rl].sec = shdr[i].sh_info; error = vn_rdwr(UIO_READ, nd->ni_vp, (void *)ef->reltab[rl].rel, shdr[i].sh_size, shdr[i].sh_offset, UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, &resid, td); if (error) goto out; if (resid != 0){ error = EINVAL; goto out; } rl++; break; case SHT_RELA: ef->relatab[ra].rela = malloc(shdr[i].sh_size, M_LINKER, M_WAITOK); ef->relatab[ra].nrela = shdr[i].sh_size / sizeof(Elf_Rela); ef->relatab[ra].sec = shdr[i].sh_info; error = vn_rdwr(UIO_READ, nd->ni_vp, (void *)ef->relatab[ra].rela, shdr[i].sh_size, shdr[i].sh_offset, UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, &resid, td); if (error) goto out; if (resid != 0){ error = EINVAL; goto out; } ra++; break; } } if (pb != ef->nprogtab) { link_elf_error(filename, "lost progbits"); error = ENOEXEC; goto out; } if (rl != ef->nreltab) { link_elf_error(filename, "lost reltab"); error = ENOEXEC; goto out; } if (ra != ef->nrelatab) { link_elf_error(filename, "lost relatab"); error = ENOEXEC; goto out; } if (mapbase != (vm_offset_t)ef->address + mapsize) { printf( "%s: mapbase 0x%lx != address %p + mapsize 0x%lx (0x%lx)\n", filename != NULL ? filename : "", (u_long)mapbase, ef->address, (u_long)mapsize, (u_long)(vm_offset_t)ef->address + mapsize); error = ENOMEM; goto out; } /* Local intra-module relocations */ error = link_elf_reloc_local(lf); if (error != 0) goto out; /* Pull in dependencies */ VOP_UNLOCK(nd->ni_vp, 0); error = linker_load_dependencies(lf); vn_lock(nd->ni_vp, LK_EXCLUSIVE | LK_RETRY); if (error) goto out; /* External relocations */ error = relocate_file(ef); if (error) goto out; /* Notify MD code that a module is being loaded. */ error = elf_cpu_load_file(lf); if (error) goto out; /* Invoke .ctors */ link_elf_invoke_ctors(lf->ctors_addr, lf->ctors_size); *result = lf; out: VOP_UNLOCK(nd->ni_vp, 0); vn_close(nd->ni_vp, FREAD, td->td_ucred, td); free(nd, M_TEMP); if (error && lf) linker_file_unload(lf, LINKER_UNLOAD_FORCE); free(hdr, M_LINKER); return error; } static void link_elf_unload_file(linker_file_t file) { elf_file_t ef = (elf_file_t) file; int i; /* Notify MD code that a module is being unloaded. */ elf_cpu_unload_file(file); if (ef->progtab) { for (i = 0; i < ef->nprogtab; i++) { if (ef->progtab[i].size == 0) continue; if (ef->progtab[i].name == NULL) continue; if (!strcmp(ef->progtab[i].name, DPCPU_SETNAME)) dpcpu_free(ef->progtab[i].addr, ef->progtab[i].size); #ifdef VIMAGE else if (!strcmp(ef->progtab[i].name, VNET_SETNAME)) vnet_data_free(ef->progtab[i].addr, ef->progtab[i].size); #endif } } if (ef->preloaded) { free(ef->reltab, M_LINKER); free(ef->relatab, M_LINKER); free(ef->progtab, M_LINKER); free(ef->ctftab, M_LINKER); free(ef->ctfoff, M_LINKER); free(ef->typoff, M_LINKER); if (file->filename != NULL) preload_delete_name(file->filename); /* XXX reclaim module memory? */ return; } for (i = 0; i < ef->nreltab; i++) free(ef->reltab[i].rel, M_LINKER); for (i = 0; i < ef->nrelatab; i++) free(ef->relatab[i].rela, M_LINKER); free(ef->reltab, M_LINKER); free(ef->relatab, M_LINKER); free(ef->progtab, M_LINKER); if (ef->object) { vm_map_remove(kernel_map, (vm_offset_t) ef->address, (vm_offset_t) ef->address + (ef->object->size << PAGE_SHIFT)); } free(ef->e_shdr, M_LINKER); free(ef->ddbsymtab, M_LINKER); free(ef->ddbstrtab, M_LINKER); free(ef->shstrtab, M_LINKER); free(ef->ctftab, M_LINKER); free(ef->ctfoff, M_LINKER); free(ef->typoff, M_LINKER); } static const char * symbol_name(elf_file_t ef, Elf_Size r_info) { const Elf_Sym *ref; if (ELF_R_SYM(r_info)) { ref = ef->ddbsymtab + ELF_R_SYM(r_info); return ef->ddbstrtab + ref->st_name; } else return NULL; } static Elf_Addr findbase(elf_file_t ef, int sec) { int i; Elf_Addr base = 0; for (i = 0; i < ef->nprogtab; i++) { if (sec == ef->progtab[i].sec) { base = (Elf_Addr)ef->progtab[i].addr; break; } } return base; } static int relocate_file(elf_file_t ef) { const Elf_Rel *rellim; const Elf_Rel *rel; const Elf_Rela *relalim; const Elf_Rela *rela; const char *symname; const Elf_Sym *sym; int i; Elf_Size symidx; Elf_Addr base; /* Perform relocations without addend if there are any: */ for (i = 0; i < ef->nreltab; i++) { rel = ef->reltab[i].rel; if (rel == NULL) { link_elf_error(ef->lf.filename, "lost a reltab!"); return (ENOEXEC); } rellim = rel + ef->reltab[i].nrel; base = findbase(ef, ef->reltab[i].sec); if (base == 0) { link_elf_error(ef->lf.filename, "lost base for reltab"); return (ENOEXEC); } for ( ; rel < rellim; rel++) { symidx = ELF_R_SYM(rel->r_info); if (symidx >= ef->ddbsymcnt) continue; sym = ef->ddbsymtab + symidx; /* Local relocs are already done */ if (ELF_ST_BIND(sym->st_info) == STB_LOCAL) continue; if (elf_reloc(&ef->lf, base, rel, ELF_RELOC_REL, elf_obj_lookup)) { symname = symbol_name(ef, rel->r_info); printf("link_elf_obj: symbol %s undefined\n", symname); return (ENOENT); } } } /* Perform relocations with addend if there are any: */ for (i = 0; i < ef->nrelatab; i++) { rela = ef->relatab[i].rela; if (rela == NULL) { link_elf_error(ef->lf.filename, "lost a relatab!"); return (ENOEXEC); } relalim = rela + ef->relatab[i].nrela; base = findbase(ef, ef->relatab[i].sec); if (base == 0) { link_elf_error(ef->lf.filename, "lost base for relatab"); return (ENOEXEC); } for ( ; rela < relalim; rela++) { symidx = ELF_R_SYM(rela->r_info); if (symidx >= ef->ddbsymcnt) continue; sym = ef->ddbsymtab + symidx; /* Local relocs are already done */ if (ELF_ST_BIND(sym->st_info) == STB_LOCAL) continue; if (elf_reloc(&ef->lf, base, rela, ELF_RELOC_RELA, elf_obj_lookup)) { symname = symbol_name(ef, rela->r_info); printf("link_elf_obj: symbol %s undefined\n", symname); return (ENOENT); } } } /* * Only clean SHN_FBSD_CACHED for successful return. If we * modified symbol table for the object but found an * unresolved symbol, there is no reason to roll back. */ elf_obj_cleanup_globals_cache(ef); return (0); } static int link_elf_lookup_symbol(linker_file_t lf, const char *name, c_linker_sym_t *sym) { elf_file_t ef = (elf_file_t) lf; const Elf_Sym *symp; const char *strp; int i; for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) { strp = ef->ddbstrtab + symp->st_name; if (symp->st_shndx != SHN_UNDEF && strcmp(name, strp) == 0) { *sym = (c_linker_sym_t) symp; return 0; } } return ENOENT; } static int link_elf_symbol_values(linker_file_t lf, c_linker_sym_t sym, linker_symval_t *symval) { elf_file_t ef = (elf_file_t) lf; const Elf_Sym *es = (const Elf_Sym*) sym; if (es >= ef->ddbsymtab && es < (ef->ddbsymtab + ef->ddbsymcnt)) { symval->name = ef->ddbstrtab + es->st_name; symval->value = (caddr_t)es->st_value; symval->size = es->st_size; return 0; } return ENOENT; } static int link_elf_search_symbol(linker_file_t lf, caddr_t value, c_linker_sym_t *sym, long *diffp) { elf_file_t ef = (elf_file_t) lf; u_long off = (uintptr_t) (void *) value; u_long diff = off; u_long st_value; const Elf_Sym *es; const Elf_Sym *best = NULL; int i; for (i = 0, es = ef->ddbsymtab; i < ef->ddbsymcnt; i++, es++) { if (es->st_name == 0) continue; st_value = es->st_value; if (off >= st_value) { if (off - st_value < diff) { diff = off - st_value; best = es; if (diff == 0) break; } else if (off - st_value == diff) { best = es; } } } if (best == NULL) *diffp = off; else *diffp = diff; *sym = (c_linker_sym_t) best; return 0; } /* * Look up a linker set on an ELF system. */ static int link_elf_lookup_set(linker_file_t lf, const char *name, void ***startp, void ***stopp, int *countp) { elf_file_t ef = (elf_file_t)lf; void **start, **stop; int i, count; /* Relative to section number */ for (i = 0; i < ef->nprogtab; i++) { if ((strncmp(ef->progtab[i].name, "set_", 4) == 0) && strcmp(ef->progtab[i].name + 4, name) == 0) { start = (void **)ef->progtab[i].addr; stop = (void **)((char *)ef->progtab[i].addr + ef->progtab[i].size); count = stop - start; if (startp) *startp = start; if (stopp) *stopp = stop; if (countp) *countp = count; return (0); } } return (ESRCH); } static int link_elf_each_function_name(linker_file_t file, int (*callback)(const char *, void *), void *opaque) { elf_file_t ef = (elf_file_t)file; const Elf_Sym *symp; int i, error; /* Exhaustive search */ for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) { if (symp->st_value != 0 && ELF_ST_TYPE(symp->st_info) == STT_FUNC) { error = callback(ef->ddbstrtab + symp->st_name, opaque); if (error) return (error); } } return (0); } static int link_elf_each_function_nameval(linker_file_t file, linker_function_nameval_callback_t callback, void *opaque) { linker_symval_t symval; elf_file_t ef = (elf_file_t)file; const Elf_Sym* symp; int i, error; /* Exhaustive search */ for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) { if (symp->st_value != 0 && ELF_ST_TYPE(symp->st_info) == STT_FUNC) { error = link_elf_symbol_values(file, (c_linker_sym_t) symp, &symval); if (error) return (error); error = callback(file, i, &symval, opaque); if (error) return (error); } } return (0); } static void elf_obj_cleanup_globals_cache(elf_file_t ef) { Elf_Sym *sym; Elf_Size i; for (i = 0; i < ef->ddbsymcnt; i++) { sym = ef->ddbsymtab + i; if (sym->st_shndx == SHN_FBSD_CACHED) { sym->st_shndx = SHN_UNDEF; sym->st_value = 0; } } } /* * Symbol lookup function that can be used when the symbol index is known (ie * in relocations). It uses the symbol index instead of doing a fully fledged * hash table based lookup when such is valid. For example for local symbols. * This is not only more efficient, it's also more correct. It's not always * the case that the symbol can be found through the hash table. */ static int elf_obj_lookup(linker_file_t lf, Elf_Size symidx, int deps, Elf_Addr *res) { elf_file_t ef = (elf_file_t)lf; Elf_Sym *sym; const char *symbol; Elf_Addr res1; /* Don't even try to lookup the symbol if the index is bogus. */ if (symidx >= ef->ddbsymcnt) { *res = 0; return (EINVAL); } sym = ef->ddbsymtab + symidx; /* Quick answer if there is a definition included. */ if (sym->st_shndx != SHN_UNDEF) { *res = sym->st_value; return (0); } /* If we get here, then it is undefined and needs a lookup. */ switch (ELF_ST_BIND(sym->st_info)) { case STB_LOCAL: /* Local, but undefined? huh? */ *res = 0; return (EINVAL); case STB_GLOBAL: case STB_WEAK: /* Relative to Data or Function name */ symbol = ef->ddbstrtab + sym->st_name; /* Force a lookup failure if the symbol name is bogus. */ if (*symbol == 0) { *res = 0; return (EINVAL); } res1 = (Elf_Addr)linker_file_lookup_symbol(lf, symbol, deps); /* * Cache global lookups during module relocation. The failure * case is particularly expensive for callers, who must scan * through the entire globals table doing strcmp(). Cache to * avoid doing such work repeatedly. * * After relocation is complete, undefined globals will be * restored to SHN_UNDEF in elf_obj_cleanup_globals_cache(), * above. */ if (res1 != 0) { sym->st_shndx = SHN_FBSD_CACHED; sym->st_value = res1; *res = res1; return (0); } else if (ELF_ST_BIND(sym->st_info) == STB_WEAK) { sym->st_value = 0; *res = 0; return (0); } return (EINVAL); default: return (EINVAL); } } static void link_elf_fix_link_set(elf_file_t ef) { static const char startn[] = "__start_"; static const char stopn[] = "__stop_"; Elf_Sym *sym; const char *sym_name, *linkset_name; Elf_Addr startp, stopp; Elf_Size symidx; int start, i; startp = stopp = 0; for (symidx = 1 /* zero entry is special */; symidx < ef->ddbsymcnt; symidx++) { sym = ef->ddbsymtab + symidx; if (sym->st_shndx != SHN_UNDEF) continue; sym_name = ef->ddbstrtab + sym->st_name; if (strncmp(sym_name, startn, sizeof(startn) - 1) == 0) { start = 1; linkset_name = sym_name + sizeof(startn) - 1; } else if (strncmp(sym_name, stopn, sizeof(stopn) - 1) == 0) { start = 0; linkset_name = sym_name + sizeof(stopn) - 1; } else continue; for (i = 0; i < ef->nprogtab; i++) { if (strcmp(ef->progtab[i].name, linkset_name) == 0) { startp = (Elf_Addr)ef->progtab[i].addr; stopp = (Elf_Addr)(startp + ef->progtab[i].size); break; } } if (i == ef->nprogtab) continue; sym->st_value = start ? startp : stopp; sym->st_shndx = i; } } static int link_elf_reloc_local(linker_file_t lf) { elf_file_t ef = (elf_file_t)lf; const Elf_Rel *rellim; const Elf_Rel *rel; const Elf_Rela *relalim; const Elf_Rela *rela; const Elf_Sym *sym; Elf_Addr base; int i; Elf_Size symidx; link_elf_fix_link_set(ef); /* Perform relocations without addend if there are any: */ for (i = 0; i < ef->nreltab; i++) { rel = ef->reltab[i].rel; if (rel == NULL) { link_elf_error(ef->lf.filename, "lost a reltab"); return (ENOEXEC); } rellim = rel + ef->reltab[i].nrel; base = findbase(ef, ef->reltab[i].sec); if (base == 0) { link_elf_error(ef->lf.filename, "lost base for reltab"); return (ENOEXEC); } for ( ; rel < rellim; rel++) { symidx = ELF_R_SYM(rel->r_info); if (symidx >= ef->ddbsymcnt) continue; sym = ef->ddbsymtab + symidx; /* Only do local relocs */ if (ELF_ST_BIND(sym->st_info) != STB_LOCAL) continue; elf_reloc_local(lf, base, rel, ELF_RELOC_REL, elf_obj_lookup); } } /* Perform relocations with addend if there are any: */ for (i = 0; i < ef->nrelatab; i++) { rela = ef->relatab[i].rela; if (rela == NULL) { link_elf_error(ef->lf.filename, "lost a relatab!"); return (ENOEXEC); } relalim = rela + ef->relatab[i].nrela; base = findbase(ef, ef->relatab[i].sec); if (base == 0) { link_elf_error(ef->lf.filename, "lost base for reltab"); return (ENOEXEC); } for ( ; rela < relalim; rela++) { symidx = ELF_R_SYM(rela->r_info); if (symidx >= ef->ddbsymcnt) continue; sym = ef->ddbsymtab + symidx; /* Only do local relocs */ if (ELF_ST_BIND(sym->st_info) != STB_LOCAL) continue; elf_reloc_local(lf, base, rela, ELF_RELOC_RELA, elf_obj_lookup); } } return (0); } static long link_elf_symtab_get(linker_file_t lf, const Elf_Sym **symtab) { elf_file_t ef = (elf_file_t)lf; *symtab = ef->ddbsymtab; if (*symtab == NULL) return (0); return (ef->ddbsymcnt); } static long link_elf_strtab_get(linker_file_t lf, caddr_t *strtab) { elf_file_t ef = (elf_file_t)lf; *strtab = ef->ddbstrtab; if (*strtab == NULL) return (0); return (ef->ddbstrcnt); }