コード例 #1
0
ファイル: library.c プロジェクト: enukane/openbsd-work
elf_object_t *
_dl_tryload_shlib(const char *libname, int type, int flags)
{
	int	libfile, i;
	struct load_list *next_load, *load_list = NULL;
	Elf_Addr maxva = 0, minva = ELFDEFNNAME(NO_ADDR);
	Elf_Addr libaddr, loff, align = _dl_pagesz - 1;
	elf_object_t *object;
	char	hbuf[4096];
	Elf_Dyn *dynp = 0;
	Elf_Ehdr *ehdr;
	Elf_Phdr *phdp;
	struct stat sb;
	void *prebind_data;

#define ROUND_PG(x) (((x) + align) & ~(align))
#define TRUNC_PG(x) ((x) & ~(align))

	libfile = _dl_open(libname, O_RDONLY);
	if (libfile < 0) {
		_dl_errno = DL_CANT_OPEN;
		return(0);
	}

	if ( _dl_fstat(libfile, &sb) < 0) {
		_dl_errno = DL_CANT_OPEN;
		return(0);
	}

	for (object = _dl_objects; object != NULL; object = object->next) {
		if (object->dev == sb.st_dev &&
		    object->inode == sb.st_ino) {
			object->obj_flags |= flags & DF_1_GLOBAL;
			_dl_close(libfile);
			if (_dl_loading_object == NULL)
				_dl_loading_object = object;
			if (object->load_object != _dl_objects &&
			    object->load_object != _dl_loading_object) {
				_dl_link_grpref(object->load_object,
				    _dl_loading_object);
			}
			return(object);
		}
	}

	_dl_read(libfile, hbuf, sizeof(hbuf));
	ehdr = (Elf_Ehdr *)hbuf;
	if (ehdr->e_ident[0] != ELFMAG0  || ehdr->e_ident[1] != ELFMAG1 ||
	    ehdr->e_ident[2] != ELFMAG2 || ehdr->e_ident[3] != ELFMAG3 ||
	    ehdr->e_type != ET_DYN || ehdr->e_machine != MACHID) {
		_dl_close(libfile);
		_dl_errno = DL_NOT_ELF;
		return(0);
	}

	/*
	 *  Alright, we might have a winner!
	 *  Figure out how much VM space we need.
	 */
	phdp = (Elf_Phdr *)(hbuf + ehdr->e_phoff);
	for (i = 0; i < ehdr->e_phnum; i++, phdp++) {
		switch (phdp->p_type) {
		case PT_LOAD:
			if (phdp->p_vaddr < minva)
				minva = phdp->p_vaddr;
			if (phdp->p_vaddr + phdp->p_memsz > maxva)
				maxva = phdp->p_vaddr + phdp->p_memsz;
			break;
		case PT_DYNAMIC:
			dynp = (Elf_Dyn *)phdp->p_vaddr;
			break;
		case PT_TLS:
			_dl_printf("%s: unsupported TLS program header in %s\n",
			    _dl_progname, libname);
			_dl_close(libfile);
			_dl_errno = DL_CANT_LOAD_OBJ;
			return(0);
		default:
			break;
		}
	}
	minva = TRUNC_PG(minva);
	maxva = ROUND_PG(maxva);

	/*
	 * We map the entire area to see that we can get the VM
	 * space required. Map it unaccessible to start with.
	 *
	 * We must map the file we'll map later otherwise the VM
	 * system won't be able to align the mapping properly
	 * on VAC architectures.
	 */
	libaddr = (Elf_Addr)_dl_mmap(0, maxva - minva, PROT_NONE,
	    MAP_PRIVATE|MAP_FILE, libfile, 0);
	if (_dl_mmap_error(libaddr)) {
		_dl_printf("%s: rtld mmap failed mapping %s.\n",
		    _dl_progname, libname);
		_dl_close(libfile);
		_dl_errno = DL_CANT_MMAP;
		return(0);
	}

	loff = libaddr - minva;
	phdp = (Elf_Phdr *)(hbuf + ehdr->e_phoff);

	for (i = 0; i < ehdr->e_phnum; i++, phdp++) {
		switch (phdp->p_type) {
		case PT_LOAD: {
			char *start = (char *)(TRUNC_PG(phdp->p_vaddr)) + loff;
			Elf_Addr off = (phdp->p_vaddr & align);
			Elf_Addr size = off + phdp->p_filesz;
			void *res;

			if (size != 0) {
				res = _dl_mmap(start, ROUND_PG(size),
				    PFLAGS(phdp->p_flags),
				    MAP_FIXED|MAP_PRIVATE, libfile,
				    TRUNC_PG(phdp->p_offset));
			} else
				res = NULL;	/* silence gcc */
			next_load = _dl_malloc(sizeof(struct load_list));
			next_load->next = load_list;
			load_list = next_load;
			next_load->start = start;
			next_load->size = size;
			next_load->prot = PFLAGS(phdp->p_flags);
			if (size != 0 && _dl_mmap_error(res)) {
				_dl_printf("%s: rtld mmap failed mapping %s.\n",
				    _dl_progname, libname);
				_dl_close(libfile);
				_dl_errno = DL_CANT_MMAP;
				_dl_munmap((void *)libaddr, maxva - minva);
				_dl_load_list_free(load_list);
				return(0);
			}
			if (phdp->p_flags & PF_W) {
				/* Zero out everything past the EOF */
				if ((size & align) != 0)
					_dl_memset(start + size, 0,
					    _dl_pagesz - (size & align));
				if (ROUND_PG(size) ==
				    ROUND_PG(off + phdp->p_memsz))
					continue;
				start = start + ROUND_PG(size);
				size = ROUND_PG(off + phdp->p_memsz) -
				    ROUND_PG(size);
				res = _dl_mmap(start, size,
				    PFLAGS(phdp->p_flags),
				    MAP_FIXED|MAP_PRIVATE|MAP_ANON, -1, 0);
				if (_dl_mmap_error(res)) {
					_dl_printf("%s: rtld mmap failed mapping %s.\n",
					    _dl_progname, libname);
					_dl_close(libfile);
					_dl_errno = DL_CANT_MMAP;
					_dl_munmap((void *)libaddr, maxva - minva);
					_dl_load_list_free(load_list);
					return(0);
				}
			}
			break;
		}

		case PT_OPENBSD_RANDOMIZE:
			_dl_randombuf((char *)(phdp->p_vaddr + loff),
			    phdp->p_memsz);
			break;

		default:
			break;
		}
	}

	prebind_data = prebind_load_fd(libfile, libname);

	_dl_close(libfile);

	dynp = (Elf_Dyn *)((unsigned long)dynp + loff);
	object = _dl_finalize_object(libname, dynp,
	    (Elf_Phdr *)((char *)libaddr + ehdr->e_phoff), ehdr->e_phnum,type,
	    libaddr, loff);
	if (object) {
		object->prebind_data = prebind_data;
		object->load_size = maxva - minva;	/*XXX*/
		object->load_list = load_list;
		/* set inode, dev from stat info */
		object->dev = sb.st_dev;
		object->inode = sb.st_ino;
		object->obj_flags |= flags;
		_dl_set_sod(object->load_name, &object->sod);
	} else {
		_dl_munmap((void *)libaddr, maxva - minva);
		_dl_load_list_free(load_list);
	}
	return(object);
}
コード例 #2
0
elf_object_t *
_dl_tryload_shlib(const char *libname, int type, int flags)
{
	int libfile, i;
	struct load_list *ld, *lowld = NULL;
	elf_object_t *object;
	Elf_Dyn *dynp = 0;
	Elf_Ehdr *ehdr;
	Elf_Phdr *phdp;
	Elf_Addr load_end = 0;
	Elf_Addr align = _dl_pagesz - 1, off, size;
	struct stat sb;
	void *prebind_data;
	char hbuf[4096];

#define ROUND_PG(x) (((x) + align) & ~(align))
#define TRUNC_PG(x) ((x) & ~(align))

	libfile = _dl_open(libname, O_RDONLY);
	if (libfile < 0) {
		_dl_errno = DL_CANT_OPEN;
		return(0);
	}

	if ( _dl_fstat(libfile, &sb) < 0) {
		_dl_errno = DL_CANT_OPEN;
		return(0);
	}

	for (object = _dl_objects; object != NULL; object = object->next) {
		if (object->dev == sb.st_dev &&
		    object->inode == sb.st_ino) {
			object->obj_flags |= flags & RTLD_GLOBAL;
			_dl_close(libfile);
			if (_dl_loading_object == NULL)
				_dl_loading_object = object;
			if (object->load_object != _dl_objects &&
			    object->load_object != _dl_loading_object) {
				_dl_link_grpref(object->load_object,
				    _dl_loading_object);
			}
			return(object);
		}
	}

	_dl_read(libfile, hbuf, sizeof(hbuf));
	ehdr = (Elf_Ehdr *)hbuf;
	if (ehdr->e_ident[0] != ELFMAG0  || ehdr->e_ident[1] != ELFMAG1 ||
	    ehdr->e_ident[2] != ELFMAG2 || ehdr->e_ident[3] != ELFMAG3 ||
	    ehdr->e_type != ET_DYN || ehdr->e_machine != MACHID) {
		_dl_close(libfile);
		_dl_errno = DL_NOT_ELF;
		return(0);
	}

	/* Insertion sort */
#define LDLIST_INSERT(ld) do { \
	struct load_list **_ld; \
	for (_ld = &lowld; *_ld != NULL; _ld = &(*_ld)->next) \
		if ((*_ld)->moff > ld->moff) \
			break; \
	ld->next = *_ld; \
	*_ld = ld; \
} while (0)
	/*
	 *  Alright, we might have a winner!
	 *  Figure out how much VM space we need and set up the load
	 *  list that we'll use to find free VM space.
	 */
	phdp = (Elf_Phdr *)(hbuf + ehdr->e_phoff);
	for (i = 0; i < ehdr->e_phnum; i++, phdp++) {
		switch (phdp->p_type) {
		case PT_LOAD:
			off = (phdp->p_vaddr & align);
			size = off + phdp->p_filesz;

			ld = _dl_malloc(sizeof(struct load_list));
			ld->start = NULL;
			ld->size = size;
			ld->moff = TRUNC_PG(phdp->p_vaddr);
			ld->foff = TRUNC_PG(phdp->p_offset);
			ld->prot = PFLAGS(phdp->p_flags);
			LDLIST_INSERT(ld);

			if ((ld->prot & PROT_WRITE) == 0 ||
			    ROUND_PG(size) == ROUND_PG(off + phdp->p_memsz))
				break;
			/* This phdr has a zfod section */
			ld = _dl_malloc(sizeof(struct load_list));
			ld->start = NULL;
			ld->size = ROUND_PG(off + phdp->p_memsz) -
			    ROUND_PG(size);
			ld->moff = TRUNC_PG(phdp->p_vaddr) +
			    ROUND_PG(size);
			ld->foff = -1;
			ld->prot = PFLAGS(phdp->p_flags);
			LDLIST_INSERT(ld);
			break;
		case PT_DYNAMIC:
			dynp = (Elf_Dyn *)phdp->p_vaddr;
			break;
		default:
			break;
		}
	}

#define LOFF ((Elf_Addr)lowld->start - lowld->moff)

retry:
	for (ld = lowld; ld != NULL; ld = ld->next) {
		off_t foff;
		int fd, flags;

		/*
		 * We don't want to provide the fd/off hint for anything
		 * but the first mapping, all other might have
		 * cache-incoherent aliases and will cause this code to
		 * loop forever.
		 */
		if (ld == lowld) {
			fd = libfile;
			foff = ld->foff;
			flags = 0;
		} else {
			fd = -1;
			foff = 0;
			flags = MAP_FIXED;
		}

		ld->start = (void *)(LOFF + ld->moff);

		/*
		 * Magic here.
		 * The first mquery is done with MAP_FIXED to see if
		 * the mapping we want is free. If it's not, we redo the
		 * mquery without MAP_FIXED to get the next free mapping,
		 * adjust the base mapping address to match this free mapping
		 * and restart the process again.
		 */
		ld->start = _dl_mquery(ld->start, ROUND_PG(ld->size), ld->prot,
		    flags, fd, foff);
		if (_dl_mmap_error(ld->start)) {
			ld->start = (void *)(LOFF + ld->moff);
			ld->start = _dl_mquery(ld->start, ROUND_PG(ld->size),
			    ld->prot, flags & ~MAP_FIXED, fd, foff);
			if (_dl_mmap_error(ld->start))
				goto fail;
		}

		if (ld->start != (void *)(LOFF + ld->moff)) {
			lowld->start = ld->start - ld->moff + lowld->moff;
			goto retry;
		}
		/*
		 * XXX - we need some kind of boundary condition here,
		 * or fix mquery to not run into the stack
		 */
	}

	for (ld = lowld; ld != NULL; ld = ld->next) {
		int fd, flags;
		off_t foff;
		void *res;

		if (ld->foff < 0) {
			fd = -1;
			foff = 0;
			flags = MAP_FIXED|MAP_PRIVATE|MAP_ANON;
		} else {
			fd = libfile;
			foff = ld->foff;
			flags = MAP_FIXED|MAP_PRIVATE;
		}
		res = _dl_mmap(ld->start, ROUND_PG(ld->size), ld->prot, flags,
		    fd, foff);
		if (_dl_mmap_error(res))
			goto fail;
		/* Zero out everything past the EOF */
		if ((ld->prot & PROT_WRITE) != 0 && (ld->size & align) != 0)
			_dl_memset((char *)ld->start + ld->size, 0,
			    _dl_pagesz - (ld->size & align));
		load_end = (Elf_Addr)ld->start + ROUND_PG(ld->size);
	}

	prebind_data = prebind_load_fd(libfile, libname);

	_dl_close(libfile);

	dynp = (Elf_Dyn *)((unsigned long)dynp + LOFF);
	object = _dl_finalize_object(libname, dynp, 
	    (Elf_Phdr *)((char *)lowld->start + ehdr->e_phoff), ehdr->e_phnum,
	    type, (Elf_Addr)lowld->start, LOFF);
	if (object) {
		object->prebind_data = prebind_data;
		object->load_size = (Elf_Addr)load_end - (Elf_Addr)lowld->start;
		object->load_list = lowld;
		/* set inode, dev from stat info */
		object->dev = sb.st_dev;
		object->inode = sb.st_ino;
		object->obj_flags |= flags;
		_dl_build_sod(object->load_name, &object->sod);
	} else {
		/* XXX no point. object is never returned NULL */
		_dl_load_list_free(lowld);
	}
	return(object);
fail:
	_dl_printf("%s: rtld mmap failed mapping %s.\n",
	    _dl_progname, libname);
	_dl_close(libfile);
	_dl_errno = DL_CANT_MMAP;
	_dl_load_list_free(lowld);
	return(0);
}