コード例 #1
0
ファイル: link_elf_obj.c プロジェクト: coyizumi/cs111
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;

	NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, filename, td);
	flags = FREAD;
	error = vn_open(&nd, &flags, 0, NULL);
	if (error)
		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:
			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)
		panic("lost symbol table index");
	/* 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)
		panic("lost symbol string index");
	/* 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:
			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:
			alignmask = shdr[i].sh_addralign - 1;
			mapbase += alignmask;
			mapbase &= ~alignmask;
			if (ef->shstrtab && shdr[i].sh_name != 0)
				ef->progtab[pb].name =
				    ef->shstrtab + shdr[i].sh_name;
			else if (shdr[i].sh_type == SHT_PROGBITS)
				ef->progtab[pb].name = "<<PROGBITS>>";
			else
				ef->progtab[pb].name = "<<NOBITS>>";
			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) {
				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)
		panic("lost progbits");
	if (rl != ef->nreltab)
		panic("lost reltab");
	if (ra != ef->nrelatab)
		panic("lost relatab");
	if (mapbase != (vm_offset_t)ef->address + mapsize)
		panic("mapbase 0x%lx != address %p + mapsize 0x%lx (0x%lx)\n",
		    (u_long)mapbase, ef->address, (u_long)mapsize,
		    (u_long)(vm_offset_t)ef->address + mapsize);

	/* Local intra-module relocations */
	link_elf_reloc_local(lf);

	/* 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;

	*result = lf;

out:
	VOP_UNLOCK(nd.ni_vp, 0);
	vn_close(nd.ni_vp, FREAD, td->td_ucred, td);
	if (error && lf)
		linker_file_unload(lf, LINKER_UNLOAD_FORCE);
	if (hdr)
		free(hdr, M_LINKER);

	return error;
}
コード例 #2
0
ファイル: link_elf_obj.c プロジェクト: 2asoft/freebsd
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);
}
コード例 #3
0
ファイル: link_elf.c プロジェクト: wan721/DragonFlyBSD
static int
link_elf_load_file(const char* filename, linker_file_t* result)
{
    struct nlookupdata nd;
    struct thread *td = curthread;	/* XXX */
    struct proc *p = td->td_proc;
    struct vnode *vp;
    Elf_Ehdr *hdr;
    caddr_t firstpage;
    int nbytes, i;
    Elf_Phdr *phdr;
    Elf_Phdr *phlimit;
    Elf_Phdr *segs[2];
    int nsegs;
    Elf_Phdr *phdyn;
    caddr_t mapbase;
    size_t mapsize;
    Elf_Addr base_vaddr;
    Elf_Addr base_vlimit;
    int error = 0;
    int resid;
    elf_file_t ef;
    linker_file_t lf;
    char *pathname;
    Elf_Shdr *shdr;
    int symtabindex;
    int symstrindex;
    int symcnt;
    int strcnt;

    /* XXX Hack for firmware loading where p == NULL */
    if (p == NULL) {
	p = &proc0;
    }

    KKASSERT(p != NULL);
    if (p->p_ucred == NULL) {
	kprintf("link_elf_load_file: cannot load '%s' from filesystem"
		" this early\n", filename);
	return ENOENT;
    }
    shdr = NULL;
    lf = NULL;
    pathname = linker_search_path(filename);
    if (pathname == NULL)
	return ENOENT;

    error = nlookup_init(&nd, pathname, UIO_SYSSPACE, NLC_FOLLOW|NLC_LOCKVP);
    if (error == 0)
	error = vn_open(&nd, NULL, FREAD, 0);
    kfree(pathname, M_LINKER);
    if (error) {
	nlookup_done(&nd);
	return error;
    }
    vp = nd.nl_open_vp;
    nd.nl_open_vp = NULL;
    nlookup_done(&nd);

    /*
     * Read the elf header from the file.
     */
    firstpage = kmalloc(PAGE_SIZE, M_LINKER, M_WAITOK);
    hdr = (Elf_Ehdr *)firstpage;
    error = vn_rdwr(UIO_READ, vp, firstpage, PAGE_SIZE, 0,
		    UIO_SYSSPACE, IO_NODELOCKED, p->p_ucred, &resid);
    nbytes = PAGE_SIZE - resid;
    if (error)
	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("Unsupported file layout");
	error = ENOEXEC;
	goto out;
    }
    if (hdr->e_ident[EI_VERSION] != EV_CURRENT
      || hdr->e_version != EV_CURRENT) {
	link_elf_error("Unsupported file version");
	error = ENOEXEC;
	goto out;
    }
    if (hdr->e_type != ET_EXEC && hdr->e_type != ET_DYN) {
	error = ENOSYS;
	goto out;
    }
    if (hdr->e_machine != ELF_TARG_MACH) {
	link_elf_error("Unsupported machine");
	error = ENOEXEC;
	goto out;
    }

    /*
     * We rely on the program header being in the first page.  This is
     * not strictly required by the ABI specification, but it seems to
     * always true in practice.  And, it simplifies things considerably.
     */
    if (!((hdr->e_phentsize == sizeof(Elf_Phdr)) &&
	  (hdr->e_phoff + hdr->e_phnum*sizeof(Elf_Phdr) <= PAGE_SIZE) &&
	  (hdr->e_phoff + hdr->e_phnum*sizeof(Elf_Phdr) <= nbytes)))
	link_elf_error("Unreadable program headers");

    /*
     * Scan the program header entries, and save key information.
     *
     * We rely on there being exactly two load segments, text and data,
     * in that order.
     */
    phdr = (Elf_Phdr *) (firstpage + hdr->e_phoff);
    phlimit = phdr + hdr->e_phnum;
    nsegs = 0;
    phdyn = NULL;
    while (phdr < phlimit) {
	switch (phdr->p_type) {

	case PT_LOAD:
	    if (nsegs == 2) {
		link_elf_error("Too many sections");
		error = ENOEXEC;
		goto out;
	    }
	    segs[nsegs] = phdr;
	    ++nsegs;
	    break;

	case PT_PHDR:
	    break;

	case PT_DYNAMIC:
	    phdyn = phdr;
	    break;

	case PT_INTERP:
	    error = ENOSYS;
	    goto out;
	}

	++phdr;
    }
    if (phdyn == NULL) {
	link_elf_error("Object is not dynamically-linked");
	error = ENOEXEC;
	goto out;
    }

    /*
     * Allocate the entire address space of the object, to stake out our
     * contiguous region, and to establish the base address for relocation.
     */
    base_vaddr = trunc_page(segs[0]->p_vaddr);
    base_vlimit = round_page(segs[1]->p_vaddr + segs[1]->p_memsz);
    mapsize = base_vlimit - base_vaddr;

    ef = kmalloc(sizeof(struct elf_file), M_LINKER, M_WAITOK | M_ZERO);
    ef->address = kmalloc(mapsize, M_LINKER, M_WAITOK);
    mapbase = ef->address;

    /*
     * Read the text and data sections and zero the bss.
     */
    for (i = 0; i < 2; i++) {
	caddr_t segbase = mapbase + segs[i]->p_vaddr - base_vaddr;
	error = vn_rdwr(UIO_READ, vp,
			segbase, segs[i]->p_filesz, segs[i]->p_offset,
			UIO_SYSSPACE, IO_NODELOCKED, p->p_ucred, &resid);
	if (error) {
	    kfree(ef->address, M_LINKER);
	    kfree(ef, M_LINKER);
	    goto out;
	}
	bzero(segbase + segs[i]->p_filesz,
	      segs[i]->p_memsz - segs[i]->p_filesz);
    }

    ef->dynamic = (const Elf_Dyn *) (mapbase + phdyn->p_vaddr - base_vaddr);

    lf = linker_make_file(filename, ef, &link_elf_file_ops);
    if (lf == NULL) {
	kfree(ef->address, M_LINKER);
	kfree(ef, M_LINKER);
	error = ENOMEM;
	goto out;
    }
    lf->address = ef->address;
    lf->size = mapsize;

    error = parse_dynamic(lf);
    if (error)
	goto out;
    link_elf_reloc_local(lf);
    error = linker_load_dependencies(lf);
    if (error)
	goto out;
    error = relocate_file(lf);
    if (error)
	goto out;

    /* Try and load the symbol table if it's present.  (you can strip it!) */
    nbytes = hdr->e_shnum * hdr->e_shentsize;
    if (nbytes == 0 || hdr->e_shoff == 0)
	goto nosyms;
    shdr = kmalloc(nbytes, M_LINKER, M_WAITOK | M_ZERO);
    error = vn_rdwr(UIO_READ, vp,
		    (caddr_t)shdr, nbytes, hdr->e_shoff,
		    UIO_SYSSPACE, IO_NODELOCKED, p->p_ucred, &resid);
    if (error)
	goto out;
    symtabindex = -1;
    symstrindex = -1;
    for (i = 0; i < hdr->e_shnum; i++) {
	if (shdr[i].sh_type == SHT_SYMTAB) {
	    symtabindex = i;
	    symstrindex = shdr[i].sh_link;
	}
    }
    if (symtabindex < 0 || symstrindex < 0)
	goto nosyms;

    symcnt = shdr[symtabindex].sh_size;
    ef->symbase = kmalloc(symcnt, M_LINKER, M_WAITOK);
    strcnt = shdr[symstrindex].sh_size;
    ef->strbase = kmalloc(strcnt, M_LINKER, M_WAITOK);
    error = vn_rdwr(UIO_READ, vp,
		    ef->symbase, symcnt, shdr[symtabindex].sh_offset,
		    UIO_SYSSPACE, IO_NODELOCKED, p->p_ucred, &resid);
    if (error)
	goto out;
    error = vn_rdwr(UIO_READ, vp,
		    ef->strbase, strcnt, shdr[symstrindex].sh_offset,
		    UIO_SYSSPACE, IO_NODELOCKED, p->p_ucred, &resid);
    if (error)
	goto out;

    ef->ddbsymcnt = symcnt / sizeof(Elf_Sym);
    ef->ddbsymtab = (const Elf_Sym *)ef->symbase;
    ef->ddbstrcnt = strcnt;
    ef->ddbstrtab = ef->strbase;

nosyms:

    *result = lf;

out:
    if (error && lf)
	linker_file_unload(lf);
    if (shdr)
	kfree(shdr, M_LINKER);
    if (firstpage)
	kfree(firstpage, M_LINKER);
    vn_unlock(vp);
    vn_close(vp, FREAD, NULL);

    return error;
}
コード例 #4
0
ファイル: link_elf_obj.c プロジェクト: 2asoft/freebsd
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);
}