irixelf.c

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	*name = NULL;
	for(i = 0; i < pnum; i++, epp++) {
		if (epp->p_type != PT_INTERP)
			continue;

		/* It is illegal to have two interpreters for one executable. */
		if (*name != NULL)
			goto out;

		*name = (char *) kmalloc((epp->p_filesz +
					  strlen(IRIX_INTERP_PREFIX)),
					 GFP_KERNEL);
		if (!*name)
			return -ENOMEM;

		strcpy(*name, IRIX_INTERP_PREFIX);
		retval = kernel_read(bprm->file, epp->p_offset, (*name + 16),
		                     epp->p_filesz);
		if (retval < 0)
			goto out;

		file = open_exec(*name);
		if (IS_ERR(file)) {
			retval = PTR_ERR(file);
			goto out;
		}
		retval = kernel_read(file, 0, bprm->buf, 128);
		if (retval < 0)
			goto dput_and_out;

		*interp_elf_ex = *(struct elfhdr *) bprm->buf;
	}
	*interpreter = file;
	return 0;

dput_and_out:
	fput(file);
out:
	kfree(*name);
	return retval;
}

static inline int verify_irix_interpreter(struct elfhdr *ihp)
{
	if (memcmp(ihp->e_ident, ELFMAG, SELFMAG) != 0)
		return -ELIBBAD;
	return 0;
}

#define EXEC_MAP_FLAGS (MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE)

static inline void map_executable(struct file *fp, struct elf_phdr *epp, int pnum,
				  unsigned int *estack, unsigned int *laddr,
				  unsigned int *scode, unsigned int *ebss,
				  unsigned int *ecode, unsigned int *edata,
				  unsigned int *ebrk)
{
	unsigned int tmp;
	int i, prot;

	for(i = 0; i < pnum; i++, epp++) {
		if(epp->p_type != PT_LOAD)
			continue;

		/* Map it. */
		prot  = (epp->p_flags & PF_R) ? PROT_READ : 0;
		prot |= (epp->p_flags & PF_W) ? PROT_WRITE : 0;
		prot |= (epp->p_flags & PF_X) ? PROT_EXEC : 0;
	        down(&current->mm->mmap_sem);
		(void) do_mmap(fp, (epp->p_vaddr & 0xfffff000),
			       (epp->p_filesz + (epp->p_vaddr & 0xfff)),
			       prot, EXEC_MAP_FLAGS,
			       (epp->p_offset & 0xfffff000));
	        up(&current->mm->mmap_sem);

		/* Fixup location tracking vars. */
		if((epp->p_vaddr & 0xfffff000) < *estack)
			*estack = (epp->p_vaddr & 0xfffff000);
		if(!*laddr)
			*laddr = epp->p_vaddr - epp->p_offset;
		if(epp->p_vaddr < *scode)
			*scode = epp->p_vaddr;

		tmp = epp->p_vaddr + epp->p_filesz;
		if(tmp > *ebss)
			*ebss = tmp;
		if((epp->p_flags & PF_X) && *ecode < tmp)
			*ecode = tmp;
		if(*edata < tmp)
			*edata = tmp;

		tmp = epp->p_vaddr + epp->p_memsz;
		if(tmp > *ebrk)
			*ebrk = tmp;
	}

}

static inline int map_interpreter(struct elf_phdr *epp, struct elfhdr *ihp,
				  struct file *interp, unsigned int *iladdr,
				  int pnum, mm_segment_t old_fs,
				  unsigned int *eentry)
{
	int i;

	*eentry = 0xffffffff;
	for(i = 0; i < pnum; i++, epp++) {
		if(epp->p_type != PT_INTERP)
			continue;

		/* We should have fielded this error elsewhere... */
		if(*eentry != 0xffffffff)
			return -1;

		set_fs(old_fs);
		*eentry = load_irix_interp(ihp, interp, iladdr);
		old_fs = get_fs();
		set_fs(get_ds());

		fput(interp);

		if (*eentry == 0xffffffff)
			return -1;
	}
	return 0;
}

/*
 * IRIX maps a page at 0x200000 that holds information about the 
 * process and the system, here we map the page and fill the
 * structure
 */
void irix_map_prda_page (void)
{
	unsigned long v;
	struct prda *pp;

	v =  do_brk (PRDA_ADDRESS, PAGE_SIZE);
	
	if (v < 0)
		return;

	pp = (struct prda *) v;
	pp->prda_sys.t_pid  = current->pid;
	pp->prda_sys.t_prid = read_32bit_cp0_register (CP0_PRID);
	pp->prda_sys.t_rpid = current->pid;

	/* We leave the rest set to zero */
}
	

	
/* These are the functions used to load ELF style executables and shared
 * libraries.  There is no binary dependent code anywhere else.
 */
static int load_irix_binary(struct linux_binprm * bprm, struct pt_regs * regs)
{
	struct elfhdr elf_ex, interp_elf_ex;
	struct file *interpreter;
	struct elf_phdr *elf_phdata, *elf_ihdr, *elf_ephdr;
	unsigned int load_addr, elf_bss, elf_brk;
	unsigned int elf_entry, interp_load_addr = 0;
	unsigned int start_code, end_code, end_data, elf_stack;
	int retval, has_interp, has_ephdr, size, i;
	char *elf_interpreter;
	mm_segment_t old_fs;
	
	load_addr = 0;
	has_interp = has_ephdr = 0;
	elf_ihdr = elf_ephdr = 0;
	elf_ex = *((struct elfhdr *) bprm->buf);
	retval = -ENOEXEC;

	if (verify_binary(&elf_ex, bprm))
		goto out;

#ifdef DEBUG_ELF
	print_elfhdr(&elf_ex);
#endif

	/* Now read in all of the header information */
	size = elf_ex.e_phentsize * elf_ex.e_phnum;
	if (size > 65536)
		goto out;
	elf_phdata = (struct elf_phdr *) kmalloc(size, GFP_KERNEL);
	if (elf_phdata == NULL) {
		retval = -ENOMEM;
		goto out;
	}

	retval = kernel_read(bprm->file, elf_ex.e_phoff, (char *)elf_phdata, size);
	if (retval < 0)
		goto out_free_ph;

#ifdef DEBUG_ELF
	dump_phdrs(elf_phdata, elf_ex.e_phnum);
#endif

	/* Set some things for later. */
	for(i = 0; i < elf_ex.e_phnum; i++) {
		switch(elf_phdata[i].p_type) {
		case PT_INTERP:
			has_interp = 1;
			elf_ihdr = &elf_phdata[i];
			break;
		case PT_PHDR:
			has_ephdr = 1;
			elf_ephdr = &elf_phdata[i];
			break;
		};
	}
#ifdef DEBUG_ELF
	printk("\n");
#endif

	elf_bss = 0;
	elf_brk = 0;

	elf_stack = 0xffffffff;
	elf_interpreter = NULL;
	start_code = 0xffffffff;
	end_code = 0;
	end_data = 0;

	retval = look_for_irix_interpreter(&elf_interpreter,
	                                   &interpreter,
					   &interp_elf_ex, elf_phdata, bprm,
					   elf_ex.e_phnum);
	if (retval)
		goto out_free_file;

	if (elf_interpreter) {
		retval = verify_irix_interpreter(&interp_elf_ex);
		if(retval)
			goto out_free_interp;
	}

	/* OK, we are done with that, now set up the arg stuff,
	 * and then start this sucker up.
	 */
	retval = -E2BIG;
	if (!bprm->sh_bang && !bprm->p)
		goto out_free_interp;

	/* Flush all traces of the currently running executable */
	retval = flush_old_exec(bprm);
	if (retval)
		goto out_free_dentry;

	/* OK, This is the point of no return */
	current->mm->end_data = 0;
	current->mm->end_code = 0;
	current->mm->mmap = NULL;
	current->flags &= ~PF_FORKNOEXEC;
	elf_entry = (unsigned int) elf_ex.e_entry;
	
	/* Do this so that we can load the interpreter, if need be.  We will
	 * change some of these later.
	 */
	current->mm->rss = 0;
	setup_arg_pages(bprm);
	current->mm->start_stack = bprm->p;

	/* At this point, we assume that the image should be loaded at
	 * fixed address, not at a variable address.
	 */
	old_fs = get_fs();
	set_fs(get_ds());

	map_executable(bprm->file, elf_phdata, elf_ex.e_phnum, &elf_stack,
	               &load_addr, &start_code, &elf_bss, &end_code,
	               &end_data, &elf_brk);

	if(elf_interpreter) {
		retval = map_interpreter(elf_phdata, &interp_elf_ex,
					 interpreter, &interp_load_addr,
					 elf_ex.e_phnum, old_fs, &elf_entry);
		kfree(elf_interpreter);
		if(retval) {
			set_fs(old_fs);
			printk("Unable to load IRIX ELF interpreter\n");
			send_sig(SIGSEGV, current, 0);
			retval = 0;
			goto out_free_file;
		}
	}

	set_fs(old_fs);

	kfree(elf_phdata);
	set_personality(PER_IRIX32);
	set_binfmt(&irix_format);
	compute_creds(bprm);
	current->flags &= ~PF_FORKNOEXEC;
	bprm->p = (unsigned long) 
	  create_irix_tables((char *)bprm->p, bprm->argc, bprm->envc,
			(elf_interpreter ? &elf_ex : NULL),
			load_addr, interp_load_addr, regs, elf_ephdr);
	current->mm->start_brk = current->mm->brk = elf_brk;
	current->mm->end_code = end_code;
	current->mm->start_code = start_code;
	current->mm->end_data = end_data;
	current->mm->start_stack = bprm->p;

	/* Calling set_brk effectively mmaps the pages that we need for the
	 * bss and break sections.
	 */
	set_brk(elf_bss, elf_brk);

	/*
	 * IRIX maps a page at 0x200000 which holds some system
	 * information.  Programs depend on this.
	 */
	irix_map_prda_page ();

	padzero(elf_bss);

#ifdef DEBUG_ELF
	printk("(start_brk) %lx\n" , (long) current->mm->start_brk);
	printk("(end_code) %lx\n" , (long) current->mm->end_code);
	printk("(start_code) %lx\n" , (long) current->mm->start_code);
	printk("(end_data) %lx\n" , (long) current->mm->end_data);
	printk("(start_stack) %lx\n" , (long) current->mm->start_stack);
	printk("(brk) %lx\n" , (long) current->mm->brk);
#endif

#if 0 /* XXX No fucking way dude... */
	/* Why this, you ask???  Well SVr4 maps page 0 as read-only,
	 * and some applications "depend" upon this behavior.
	 * Since we do not have the power to recompile these, we
	 * emulate the SVr4 behavior.  Sigh.
	 */
	down(&current->mm->mmap_sem);
	(void) do_mmap(NULL, 0, 4096, PROT_READ | PROT_EXEC,
		       MAP_FIXED | MAP_PRIVATE, 0);
	up(&current->mm->mmap_sem);
#endif

	start_thread(regs, elf_entry, bprm->p);
	if (current->ptrace & PT_PTRACED)
		send_sig(SIGTRAP, current, 0);
	return 0;
out:
	return retval;

out_free_dentry:
	allow_write_access(interpreter);
	fput(interpreter);
out_free_interp:
	if (elf_interpreter)
		kfree(elf_interpreter);
out_free_file:
out_free_ph:
	kfree (elf_phdata);
	goto out;
}

/* This is really simpleminded and specialized - we are loading an
 * a.out library that is given an ELF header.
 */
static int load_irix_library(struct file *file)
{
	struct elfhdr elf_ex;
	struct elf_phdr *elf_phdata  =  NULL;
	unsigned int len = 0;
	int elf_bss = 0;
	int retval;
	unsigned int bss;
	int error;
	int i,j, k;

	error = kernel_read(file, 0, (char *) &elf_ex, sizeof(elf_ex));
	if (error != sizeof(elf_ex))
		return -ENOEXEC;

	if (memcmp(elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
		return -ENOEXEC;

	/* First of all, some simple consistency checks. */
	if(elf_ex.e_type != ET_EXEC || elf_ex.e_phnum > 2 ||
	   !irix_elf_check_arch(&elf_ex) || !file->f_op->mmap)
		return -ENOEXEC;
	
	/* Now read in all of the header information. */
	if(sizeof(struct elf_phdr) * elf_ex.e_phnum > PAGE_SIZE)
		return -ENOEXEC;
	
	elf_phdata =  (struct elf_phdr *) 
		kmalloc(sizeof(struct elf_phdr) * elf_ex.e_phnum, GFP_KERNEL);
	if (elf_phdata == NULL)
		return -ENOMEM;
	
	retval = kernel_read(file, elf_ex.e_phoff, (char *) elf_phdata,
			   sizeof(struct elf_phdr) * elf_ex.e_phnum);
	
	j = 0;
	for(i=0; i<elf_ex.e_phnum; i++)
		if((elf_phdata + i)->p_type == PT_LOAD) j++;
	
	if(j != 1)  {
		kfree(elf_phdata);
		return -ENOEXEC;
	}
	
	while(elf_phdata->p_type != PT_LOAD) elf_phdata++;
	
	/* Now use mmap to map the library into memory. */
	down(&current->mm->mmap_sem);
	error = do_mmap(file,
			elf_phdata->p_vaddr & 0xfffff000,
			elf_phdata->p_filesz + (elf_phdata->p_vaddr & 0xfff),
			PROT_READ | PROT_WRITE | PROT_EXEC,
			MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE,
			elf_phdata->p_offset & 0xfffff000);
	up(&current->mm->mmap_sem);

	k = elf_phdata->p_vaddr + elf_phdata->p_filesz;
	if (k > elf_bss) elf_bss = k;

	if (error != (elf_phdata->p_vaddr & 0xfffff000)) {
		kfree(elf_phdata);
		return error;
	}

	padzero(elf_bss);

	len = (elf_phdata->p_filesz + elf_phdata->p_vaddr+ 0xfff) & 0xfffff000;
	bss = elf_phdata->p_memsz + elf_phdata->p_vaddr;
	if (bss > len)
	  do_brk(len, bss-len);