dl-elf.c

Axis 221 camera embedded programing interface

	libaddr = 0;
	infile = _dl_open(libname, O_RDONLY, 0);
	if (infile < 0) {
#if 0
		/*
		 * NO!  When we open shared libraries we may search several paths.
		 * it is inappropriate to generate an error here.
		 */
		_dl_dprintf(2, "%s: can't open '%s'\n", _dl_progname, libname);
#endif
		_dl_internal_error_number = LD_ERROR_NOFILE;
		return NULL;
	}

	header = _dl_mmap((void *) 0, _dl_pagesize, PROT_READ | PROT_WRITE,
			MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
	if (_dl_mmap_check_error(header)) {
		_dl_dprintf(2, "%s: can't map '%s'\n", _dl_progname, libname);
		_dl_internal_error_number = LD_ERROR_MMAP_FAILED;
		_dl_close(infile);
		return NULL;
	};

	_dl_read(infile, header, _dl_pagesize);
	epnt = (ElfW(Ehdr) *) (intptr_t) header;
	if (epnt->e_ident[0] != 0x7f ||
			epnt->e_ident[1] != 'E' ||
			epnt->e_ident[2] != 'L' ||
			epnt->e_ident[3] != 'F')
	{
		_dl_dprintf(2, "%s: '%s' is not an ELF file\n", _dl_progname,
				libname);
		_dl_internal_error_number = LD_ERROR_NOTELF;
		_dl_close(infile);
		_dl_munmap(header, _dl_pagesize);
		return NULL;
	};

	if ((epnt->e_type != ET_DYN) || (epnt->e_machine != MAGIC1
#ifdef MAGIC2
				&& epnt->e_machine != MAGIC2
#endif
				))
	{
		_dl_internal_error_number =
			(epnt->e_type != ET_DYN ? LD_ERROR_NOTDYN : LD_ERROR_NOTMAGIC);
		_dl_dprintf(2, "%s: '%s' is not an ELF executable for " ELF_TARGET
				"\n", _dl_progname, libname);
		_dl_close(infile);
		_dl_munmap(header, _dl_pagesize);
		return NULL;
	};

	ppnt = (ElfW(Phdr) *)(intptr_t) & header[epnt->e_phoff];

	piclib = 1;
	for (i = 0; i < epnt->e_phnum; i++) {

		if (ppnt->p_type == PT_DYNAMIC) {
			if (dynamic_addr)
				_dl_dprintf(2, "%s: '%s' has more than one dynamic section\n",
						_dl_progname, libname);
			dynamic_addr = ppnt->p_vaddr;
		};

		if (ppnt->p_type == PT_LOAD) {
			/* See if this is a PIC library. */
			if (i == 0 && ppnt->p_vaddr > 0x1000000) {
				piclib = 0;
				minvma = ppnt->p_vaddr;
			}
			if (piclib && ppnt->p_vaddr < minvma) {
				minvma = ppnt->p_vaddr;
			}
			if (((unsigned long) ppnt->p_vaddr + ppnt->p_memsz) > maxvma) {
				maxvma = ppnt->p_vaddr + ppnt->p_memsz;
			}
		}
		ppnt++;
	};

	maxvma = (maxvma + ADDR_ALIGN) & ~ADDR_ALIGN;
	minvma = minvma & ~0xffffU;

	flags = MAP_PRIVATE /*| MAP_DENYWRITE */ ;
	if (!piclib)
		flags |= MAP_FIXED;

	status = (char *) _dl_mmap((char *) (piclib ? 0 : minvma),
			maxvma - minvma, PROT_NONE, flags | MAP_ANONYMOUS, -1, 0);
	if (_dl_mmap_check_error(status)) {
		_dl_dprintf(2, "%s: can't map %s\n", _dl_progname, libname);
		_dl_internal_error_number = LD_ERROR_MMAP_FAILED;
		_dl_close(infile);
		_dl_munmap(header, _dl_pagesize);
		return NULL;
	};
	libaddr = (unsigned long) status;
	flags |= MAP_FIXED;

	/* Get the memory to store the library */
	ppnt = (ElfW(Phdr) *)(intptr_t) & header[epnt->e_phoff];

	for (i = 0; i < epnt->e_phnum; i++) {
		if (ppnt->p_type == PT_GNU_RELRO) {
			relro_addr = ppnt->p_vaddr;
			relro_size = ppnt->p_memsz;
		}
		if (ppnt->p_type == PT_LOAD) {

			/* See if this is a PIC library. */
			if (i == 0 && ppnt->p_vaddr > 0x1000000) {
				piclib = 0;
				/* flags |= MAP_FIXED; */
			}



			if (ppnt->p_flags & PF_W) {
				unsigned long map_size;
				char *cpnt;

				status = (char *) _dl_mmap((char *) ((piclib ? libaddr : 0) +
							(ppnt->p_vaddr & PAGE_ALIGN)), (ppnt->p_vaddr & ADDR_ALIGN)
						+ ppnt->p_filesz, LXFLAGS(ppnt->p_flags), flags, infile,
						ppnt->p_offset & OFFS_ALIGN);

				if (_dl_mmap_check_error(status)) {
					_dl_dprintf(2, "%s: can't map '%s'\n",
							_dl_progname, libname);
					_dl_internal_error_number = LD_ERROR_MMAP_FAILED;
					_dl_munmap((char *) libaddr, maxvma - minvma);
					_dl_close(infile);
					_dl_munmap(header, _dl_pagesize);
					return NULL;
				};

				/* Pad the last page with zeroes. */
				cpnt = (char *) (status + (ppnt->p_vaddr & ADDR_ALIGN) +
						ppnt->p_filesz);
				while (((unsigned long) cpnt) & ADDR_ALIGN)
					*cpnt++ = 0;

				/* I am not quite sure if this is completely
				 * correct to do or not, but the basic way that
				 * we handle bss segments is that we mmap
				 * /dev/zero if there are any pages left over
				 * that are not mapped as part of the file */

				map_size = (ppnt->p_vaddr + ppnt->p_filesz + ADDR_ALIGN) & PAGE_ALIGN;

				if (map_size < ppnt->p_vaddr + ppnt->p_memsz)
					status = (char *) _dl_mmap((char *) map_size +
							(piclib ? libaddr : 0),
							ppnt->p_vaddr + ppnt->p_memsz - map_size,
							LXFLAGS(ppnt->p_flags), flags | MAP_ANONYMOUS, -1, 0);
			} else
				status = (char *) _dl_mmap((char *) (ppnt->p_vaddr & PAGE_ALIGN)
						+ (piclib ? libaddr : 0), (ppnt->p_vaddr & ADDR_ALIGN) +
						ppnt->p_filesz, LXFLAGS(ppnt->p_flags), flags,
						infile, ppnt->p_offset & OFFS_ALIGN);
			if (_dl_mmap_check_error(status)) {
				_dl_dprintf(2, "%s: can't map '%s'\n", _dl_progname, libname);
				_dl_internal_error_number = LD_ERROR_MMAP_FAILED;
				_dl_munmap((char *) libaddr, maxvma - minvma);
				_dl_close(infile);
				_dl_munmap(header, _dl_pagesize);
				return NULL;
			};

			/* if(libaddr == 0 && piclib) {
			   libaddr = (unsigned long) status;
			   flags |= MAP_FIXED;
			   }; */
		};
		ppnt++;
	};
	_dl_close(infile);

	/* For a non-PIC library, the addresses are all absolute */
	if (piclib) {
		dynamic_addr += (unsigned long) libaddr;
	}

	/*
	 * OK, the ELF library is now loaded into VM in the correct locations
	 * The next step is to go through and do the dynamic linking (if needed).
	 */

	/* Start by scanning the dynamic section to get all of the pointers */

	if (!dynamic_addr) {
		_dl_internal_error_number = LD_ERROR_NODYNAMIC;
		_dl_dprintf(2, "%s: '%s' is missing a dynamic section\n",
				_dl_progname, libname);
		_dl_munmap(header, _dl_pagesize);
		return NULL;
	}

	dpnt = (Elf32_Dyn *) dynamic_addr;
	_dl_memset(dynamic_info, 0, sizeof(dynamic_info));
	_dl_parse_dynamic_info(dpnt, dynamic_info, NULL);
	/* If the TEXTREL is set, this means that we need to make the pages
	   writable before we perform relocations.  Do this now. They get set
	   back again later. */

	if (dynamic_info[DT_TEXTREL]) {
#ifndef __FORCE_SHAREABLE_TEXT_SEGMENTS__
		ppnt = (ElfW(Phdr) *)(intptr_t) & header[epnt->e_phoff];
		for (i = 0; i < epnt->e_phnum; i++, ppnt++) {
			if (ppnt->p_type == PT_LOAD && !(ppnt->p_flags & PF_W))
				_dl_mprotect((void *) ((piclib ? libaddr : 0) +
							(ppnt->p_vaddr & PAGE_ALIGN)),
						(ppnt->p_vaddr & ADDR_ALIGN) + (unsigned long) ppnt->p_filesz,
						PROT_READ | PROT_WRITE | PROT_EXEC);
		}
#else
		_dl_dprintf(_dl_debug_file, "Can't modify %s's text section. Use GCC option -fPIC for shared objects, please.\n",libname);
		_dl_exit(1);
#endif
	}

	tpnt = _dl_add_elf_hash_table(libname, (char *) libaddr, dynamic_info,
			dynamic_addr, 0);
	tpnt->relro_addr = relro_addr;
	tpnt->relro_size = relro_size;
	tpnt->ppnt = (ElfW(Phdr) *)(intptr_t) (tpnt->loadaddr + epnt->e_phoff);
	tpnt->n_phent = epnt->e_phnum;

	/*
	 * Add this object into the symbol chain
	 */
	if (*rpnt) {
		(*rpnt)->next = (struct dyn_elf *) _dl_malloc(sizeof(struct dyn_elf));
		_dl_memset((*rpnt)->next, 0, sizeof(struct dyn_elf));
		(*rpnt)->next->prev = (*rpnt);
		*rpnt = (*rpnt)->next;
		(*rpnt)->dyn = tpnt;
		tpnt->symbol_scope = _dl_symbol_tables;
	}
	tpnt->usage_count++;
	tpnt->libtype = elf_lib;

	/*
	 * OK, the next thing we need to do is to insert the dynamic linker into
	 * the proper entry in the GOT so that the PLT symbols can be properly
	 * resolved.
	 */

	lpnt = (unsigned long *) dynamic_info[DT_PLTGOT];

	if (lpnt) {
		lpnt = (unsigned long *) (dynamic_info[DT_PLTGOT] +
				((int) libaddr));
		INIT_GOT(lpnt, tpnt);
	};

#if defined (__SUPPORT_LD_DEBUG__)
	if(_dl_debug) {
		_dl_dprintf(2, "\n\tfile='%s';  generating link map\n", libname);
		_dl_dprintf(2, "\t\tdynamic: %x  base: %x\n",
				dynamic_addr, libaddr);
		_dl_dprintf(2, "\t\t  entry: %x  phdr: %x  phnum: %x\n\n",
				epnt->e_entry + libaddr, tpnt->ppnt, tpnt->n_phent);

	}
#endif
	_dl_munmap(header, _dl_pagesize);

	return tpnt;
}
/* now_flag must be RTLD_NOW or zero */
int _dl_fixup(struct dyn_elf *rpnt, int now_flag)
{
	int goof = 0;
	struct elf_resolve *tpnt;
	unsigned long reloc_size;

	if (rpnt->next)
		goof += _dl_fixup(rpnt->next, now_flag);
	tpnt = rpnt->dyn;

#if defined (__SUPPORT_LD_DEBUG__)
	if(_dl_debug && !(tpnt->init_flag & RELOCS_DONE)) 
		_dl_dprintf(_dl_debug_file,"\nrelocation processing: %s\n", tpnt->libname);
#endif

	if (unlikely(tpnt->dynamic_info[UNSUPPORTED_RELOC_TYPE])) {
#if defined (__SUPPORT_LD_DEBUG__)
		if(_dl_debug) {
			_dl_dprintf(2, "%s: can't handle %s relocation records\n",
					_dl_progname, UNSUPPORTED_RELOC_STR);
		}
#endif
		goof++;
		return goof;
	}

	reloc_size = tpnt->dynamic_info[DT_RELOC_TABLE_SIZE];
/* On some machines, notably SPARC & PPC, DT_REL* includes DT_JMPREL in its
   range.  Note that according to the ELF spec, this is completely legal! */
#ifdef ELF_MACHINE_PLTREL_OVERLAP
	reloc_size -= tpnt->dynamic_info [DT_PLTRELSZ];
#endif
	if (tpnt->dynamic_info[DT_RELOC_TABLE_ADDR] &&
	    !(tpnt->init_flag & RELOCS_DONE)) {
		tpnt->init_flag |= RELOCS_DONE;
		goof += _dl_parse_relocation_information(rpnt,
				tpnt->dynamic_info[DT_RELOC_TABLE_ADDR],
				reloc_size);
	}
	if (tpnt->dynamic_info[DT_BIND_NOW])
		now_flag = RTLD_NOW;
	if (tpnt->dynamic_info[DT_JMPREL] &&
	    (!(tpnt->init_flag & JMP_RELOCS_DONE) ||
	     (now_flag && !(tpnt->rtld_flags & now_flag)))) {
		tpnt->rtld_flags |= now_flag; 
		tpnt->init_flag |= JMP_RELOCS_DONE;
		if (!(tpnt->rtld_flags & RTLD_NOW)) {
			_dl_parse_lazy_relocation_information(rpnt,
					tpnt->dynamic_info[DT_JMPREL],
					tpnt->dynamic_info [DT_PLTRELSZ]);
		} else {
			goof += _dl_parse_relocation_information(rpnt,
					tpnt->dynamic_info[DT_JMPREL],
					tpnt->dynamic_info[DT_PLTRELSZ]);
		}
	}
	return goof;
}

/* Minimal printf which handles only %s, %d, and %x */
void _dl_dprintf(int fd, const char *fmt, ...)
{
	int num;
	va_list args;
	char *start, *ptr, *string;
	static char *buf;

	buf = _dl_mmap((void *) 0, _dl_pagesize, PROT_READ | PROT_WRITE,
			MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
	if (_dl_mmap_check_error(buf)) {
		_dl_write(fd, "mmap of a spare page failed!\n", 29);
		_dl_exit(20);
	}

	start = ptr = buf;

	if (!fmt)
		return;

	if (_dl_strlen(fmt) >= (_dl_pagesize - 1)) {
		_dl_write(fd, "overflow\n", 11);
		_dl_exit(20);
	}

	_dl_strcpy(buf, fmt);
	va_start(args, fmt);

	while (start) {
		while (*ptr != '%' && *ptr) {
			ptr++;
		}

		if (*ptr == '%') {
			*ptr++ = '\0';
			_dl_write(fd, start, _dl_strlen(start));

			switch (*ptr++) {
				case 's':
					string = va_arg(args, char *);

					if (!string)
						_dl_write(fd, "(null)", 6);
					else
						_dl_write(fd, string, _dl_strlen(string));
					break;

				case 'i':
				case 'd':
					{
						char tmp[22];
						num = va_arg(args, int);

						string = _dl_simple_ltoa(tmp, num);
						_dl_write(fd, string, _dl_strlen(string));
						break;
					}
				case 'x':
				case 'X':
					{
						char tmp[22];
						num = va_arg(args, int);

						string = _dl_simple_ltoahex(tmp, num);
						_dl_write(fd, string, _dl_strlen(string));
						break;
					}
				default:
					_dl_write(fd, "(null)", 6);
					break;
			}

			start = ptr;
		} else {
			_dl_write(fd, start, _dl_strlen(start));
			start = NULL;
		}
	}
	_dl_munmap(buf, _dl_pagesize);
	return;
}

char *_dl_strdup(const char *string)
{
	char *retval;
	int len;

	len = _dl_strlen(string);
	retval = _dl_malloc(len + 1);
	_dl_strcpy(retval, string);
	return retval;
}

void _dl_parse_dynamic_info(Elf32_Dyn *dpnt, unsigned long dynamic_info[], void *debug_addr)
{
	__dl_parse_dynamic_info(dpnt, dynamic_info, debug_addr);
}
#ifdef __USE_GNU
#if ! defined LIBDL || (! defined PIC && ! defined __PIC__)
int
__dl_iterate_phdr (int (*callback) (struct dl_phdr_info *info, size_t size, void *data), void *data)
{
	struct elf_resolve *l;
	struct dl_phdr_info info;
	int ret = 0;

	for (l = _dl_loaded_modules; l != NULL; l = l->next) {
		info.dlpi_addr = l->loadaddr;
		info.dlpi_name = l->libname;
		info.dlpi_phdr = l->ppnt;
		info.dlpi_phnum = l->n_phent;
		ret = callback (&info, sizeof (struct dl_phdr_info), data);
		if (ret)
			break;
	}
	return ret;
}
strong_alias(__dl_iterate_phdr, dl_iterate_phdr);
#endif
#endif