__mprotect (mapat + c->mapend,
__mprotect ((caddr_t) (l->l_addr + c->mapend),
_dl_map_object_from_fd (const char *name, int fd, char *realname,			struct link_map *loader, int l_type){  struct link_map *l;  void *file_mapping = NULL;  size_t mapping_size = 0;#define LOSE(s) lose (0, (s))  void lose (int code, const char *msg)    {      (void) __close (fd);      if (file_mapping)	__munmap (file_mapping, mapping_size);      if (l)	{	  /* Remove the stillborn object from the list and free it.  */	  if (l->l_prev)	    l->l_prev->l_next = l->l_next;	  if (l->l_next)	    l->l_next->l_prev = l->l_prev;	  free (l);	}      free (realname);      _dl_signal_error (code, name, msg);    }  inline caddr_t map_segment (ElfW(Addr) mapstart, size_t len,			      int prot, int fixed, off_t offset)    {      caddr_t mapat = __mmap ((caddr_t) mapstart, len, prot,			      fixed|MAP_COPY|MAP_FILE,			      fd, offset);      if (mapat == (caddr_t) -1)	lose (errno, "failed to map segment from shared object");      return mapat;    }  /* Make sure LOCATION is mapped in.  */  void *map (off_t location, size_t size)    {      if ((off_t) mapping_size <= location + (off_t) size)	{	  void *result;	  if (file_mapping)	    __munmap (file_mapping, mapping_size);	  mapping_size = (location + size + 1 + _dl_pagesize - 1);	  mapping_size &= ~(_dl_pagesize - 1);	  result = __mmap (file_mapping, mapping_size, PROT_READ,			   MAP_COPY|MAP_FILE, fd, 0);	  if (result == (void *) -1)	    lose (errno, "cannot map file data");	  file_mapping = result;	}      return file_mapping + location;    }  const ElfW(Ehdr) *header;  const ElfW(Phdr) *phdr;  const ElfW(Phdr) *ph;  int type;  /* Look again to see if the real name matched another already loaded.  */  for (l = _dl_loaded; l; l = l->l_next)    if (! strcmp (realname, l->l_name))      {	/* The object is already loaded.	   Just bump its reference count and return it.  */	__close (fd);	free (realname);	++l->l_opencount;	return l;      }  if (_dl_pagesize == 0)    _dl_pagesize = __getpagesize ();  /* Map in the first page to read the header.  */  header = map (0, sizeof *header);  /* Check the header for basic validity.  */  if (*(Elf32_Word *) &header->e_ident !=#if BYTE_ORDER == LITTLE_ENDIAN      ((ELFMAG0 << (EI_MAG0 * 8)) |       (ELFMAG1 << (EI_MAG1 * 8)) |       (ELFMAG2 << (EI_MAG2 * 8)) |       (ELFMAG3 << (EI_MAG3 * 8)))#else      ((ELFMAG0 << (EI_MAG3 * 8)) |       (ELFMAG1 << (EI_MAG2 * 8)) |       (ELFMAG2 << (EI_MAG1 * 8)) |       (ELFMAG3 << (EI_MAG0 * 8)))#endif      )    LOSE ("invalid ELF header");#define ELF32_CLASS ELFCLASS32#define ELF64_CLASS ELFCLASS64  if (header->e_ident[EI_CLASS] != ELFW(CLASS))    LOSE ("ELF file class not " STRING(__ELF_WORDSIZE) "-bit");  if (header->e_ident[EI_DATA] != byteorder)    LOSE ("ELF file data encoding not " byteorder_name);  if (header->e_ident[EI_VERSION] != EV_CURRENT)    LOSE ("ELF file version ident not " STRING(EV_CURRENT));  if (header->e_version != EV_CURRENT)    LOSE ("ELF file version not " STRING(EV_CURRENT));  if (! elf_machine_matches_host (header->e_machine))    LOSE ("ELF file machine architecture not " ELF_MACHINE_NAME);  if (header->e_phentsize != sizeof (ElfW(Phdr)))    LOSE ("ELF file's phentsize not the expected size");  if (_dl_zerofd == -1)    {      _dl_zerofd = _dl_sysdep_open_zero_fill ();      if (_dl_zerofd == -1)	{	  __close (fd);	  _dl_signal_error (errno, NULL, "cannot open zero fill device");	}    }  /* Enter the new object in the list of loaded objects.  */  l = _dl_new_object (realname, name, l_type);  if (! l)    lose (ENOMEM, "cannot create shared object descriptor");  l->l_opencount = 1;  l->l_loader = loader;  /* Extract the remaining details we need from the ELF header     and then map in the program header table.  */  l->l_entry = header->e_entry;  type = header->e_type;  l->l_phnum = header->e_phnum;  phdr = map (header->e_phoff, l->l_phnum * sizeof (ElfW(Phdr)));  {    /* Scan the program header table, collecting its load commands.  */    struct loadcmd      {	ElfW(Addr) mapstart, mapend, dataend, allocend;	off_t mapoff;	int prot;      } loadcmds[l->l_phnum], *c;    size_t nloadcmds = 0;    l->l_ld = 0;    l->l_phdr = 0;    l->l_addr = 0;    for (ph = phdr; ph < &phdr[l->l_phnum]; ++ph)      switch (ph->p_type)	{	  /* These entries tell us where to find things once the file's	     segments are mapped in.  We record the addresses it says	     verbatim, and later correct for the run-time load address.  */	case PT_DYNAMIC:	  l->l_ld = (void *) ph->p_vaddr;	  break;	case PT_PHDR:	  l->l_phdr = (void *) ph->p_vaddr;	  break;	case PT_LOAD:	  /* A load command tells us to map in part of the file.	     We record the load commands and process them all later.  */	  if (ph->p_align % _dl_pagesize != 0)	    LOSE ("ELF load command alignment not page-aligned");	  if ((ph->p_vaddr - ph->p_offset) % ph->p_align)	    LOSE ("ELF load command address/offset not properly aligned");	  {	    struct loadcmd *c = &loadcmds[nloadcmds++];	    c->mapstart = ph->p_vaddr & ~(ph->p_align - 1);	    c->mapend = ((ph->p_vaddr + ph->p_filesz + _dl_pagesize - 1)			 & ~(_dl_pagesize - 1));	    c->dataend = ph->p_vaddr + ph->p_filesz;	    c->allocend = ph->p_vaddr + ph->p_memsz;	    c->mapoff = ph->p_offset & ~(ph->p_align - 1);	    c->prot = 0;	    if (ph->p_flags & PF_R)	      c->prot |= PROT_READ;	    if (ph->p_flags & PF_W)	      c->prot |= PROT_WRITE;	    if (ph->p_flags & PF_X)	      c->prot |= PROT_EXEC;	    break;	  }	}    /* We are done reading the file's headers now.  Unmap them.  */    __munmap (file_mapping, mapping_size);    /* Now process the load commands and map segments into memory.  */    c = loadcmds;    if (type == ET_DYN || type == ET_REL)      {	/* This is a position-independent shared object.  We can let the	   kernel map it anywhere it likes, but we must have space for all	   the segments in their specified positions relative to the first.	   So we map the first segment without MAP_FIXED, but with its	   extent increased to cover all the segments.  Then we remove	   access from excess portion, and there is known sufficient space	   there to remap from the later segments.  */ 	caddr_t mapat;	mapat = map_segment (c->mapstart,			     loadcmds[nloadcmds - 1].allocend - c->mapstart,			     c->prot, 0, c->mapoff);	l->l_addr = (ElfW(Addr)) mapat - c->mapstart;	/* Change protection on the excess portion to disallow all access;	   the portions we do not remap later will be inaccessible as if	   unallocated.  Then jump into the normal segment-mapping loop to	   handle the portion of the segment past the end of the file	   mapping.  */	__mprotect (mapat + c->mapend,		    loadcmds[nloadcmds - 1].allocend - c->mapend,		    0);	goto postmap;      }    while (c < &loadcmds[nloadcmds])      {	if (c->mapend > c->mapstart)	  /* Map the segment contents from the file.  */	  map_segment (l->l_addr + c->mapstart, c->mapend - c->mapstart,		       c->prot, MAP_FIXED, c->mapoff);      postmap:	if (c->allocend > c->dataend)	  {	    /* Extra zero pages should appear at the end of this segment,	       after the data mapped from the file.   */	    ElfW(Addr) zero, zeroend, zeropage;	    zero = l->l_addr + c->dataend;	    zeroend = l->l_addr + c->allocend;	    zeropage = (zero + _dl_pagesize - 1) & ~(_dl_pagesize - 1);	    if (zeroend < zeropage)	      /* All the extra data is in the last page of the segment.		 We can just zero it.  */	      zeropage = zeroend;	    if (zeropage > zero)	      {		/* Zero the final part of the last page of the segment.  */		if ((c->prot & PROT_WRITE) == 0)		  {		    /* Dag nab it.  */		    if (__mprotect ((caddr_t) (zero & ~(_dl_pagesize - 1)),				    _dl_pagesize, c->prot|PROT_WRITE) < 0)		      lose (errno, "cannot change memory protections");		  }		memset ((void *) zero, 0, zeropage - zero);		if ((c->prot & PROT_WRITE) == 0)		  __mprotect ((caddr_t) (zero & ~(_dl_pagesize - 1)),			      _dl_pagesize, c->prot);	      }	    if (zeroend > zeropage)	      {		/* Map the remaining zero pages in from the zero fill FD.  */		caddr_t mapat;		mapat = __mmap ((caddr_t) zeropage, zeroend - zeropage,				c->prot, MAP_ANON|MAP_PRIVATE|MAP_FIXED,				_dl_zerofd, 0);		if (mapat == (caddr_t) -1)		  lose (errno, "cannot map zero-fill pages");	      }	  }	++c;      }  }  /* We are done mapping in the file.  We no longer need the descriptor.  */  __close (fd);  if (l->l_type == lt_library && type == ET_EXEC)    l->l_type = lt_executable;  if (l->l_ld == 0)    {      if (type == ET_DYN)	LOSE ("object file has no dynamic section");    }  else    (ElfW(Addr)) l->l_ld += l->l_addr;  if (l->l_phdr == 0)    l->l_phdr = (void *) ((const ElfW(Ehdr) *) l->l_addr)->e_phoff;  (ElfW(Addr)) l->l_phdr += l->l_addr;  l->l_entry += l->l_addr;  elf_get_dynamic_info (l->l_ld, l->l_info);  if (l->l_info[DT_HASH])    _dl_setup_hash (l);  return l;}