insmod.c

这是一个SIGMA方案的PMP播放器的UCLINUX程序,可播放DVD,VCD,CD MP3...有很好的参考价值.

	if (sym) {
		if (sym->secidx >= SHN_LORESERVE)
			return sym->value;

		return sym->value + f->sections[sym->secidx]->header.sh_addr;
	} else {
		/* As a special case, a NULL sym has value zero.  */
		return 0;
	}
}

static struct obj_section *obj_find_section(struct obj_file *f, const char *name)
{
	int i, n = f->header.e_shnum;

	for (i = 0; i < n; ++i)
		if (strcmp(f->sections[i]->name, name) == 0)
			return f->sections[i];

	return NULL;
}

static int obj_load_order_prio(struct obj_section *a)
{
	unsigned long af, ac;

	af = a->header.sh_flags;

	ac = 0;
	if (a->name[0] != '.' || strlen(a->name) != 10 ||
		strcmp(a->name + 5, ".init"))
		ac |= 32;
	if (af & SHF_ALLOC)
		ac |= 16;
	if (!(af & SHF_WRITE))
		ac |= 8;
	if (af & SHF_EXECINSTR)
		ac |= 4;
	if (a->header.sh_type != SHT_NOBITS)
		ac |= 2;

	return ac;
}

static void
obj_insert_section_load_order(struct obj_file *f, struct obj_section *sec)
{
	struct obj_section **p;
	int prio = obj_load_order_prio(sec);
	for (p = f->load_order_search_start; *p; p = &(*p)->load_next)
		if (obj_load_order_prio(*p) < prio)
			break;
	sec->load_next = *p;
	*p = sec;
}

static struct obj_section *obj_create_alloced_section(struct obj_file *f,
											   const char *name,
											   unsigned long align,
											   unsigned long size)
{
	int newidx = f->header.e_shnum++;
	struct obj_section *sec;

	f->sections = xrealloc(f->sections, (newidx + 1) * sizeof(sec));
	f->sections[newidx] = sec = arch_new_section();

	memset(sec, 0, sizeof(*sec));
	sec->header.sh_type = SHT_PROGBITS;
	sec->header.sh_flags = SHF_WRITE | SHF_ALLOC;
	sec->header.sh_size = size;
	sec->header.sh_addralign = align;
	sec->name = name;
	sec->idx = newidx;
	if (size)
		sec->contents = xmalloc(size);

	obj_insert_section_load_order(f, sec);

	return sec;
}

static struct obj_section *obj_create_alloced_section_first(struct obj_file *f,
													 const char *name,
													 unsigned long align,
													 unsigned long size)
{
	int newidx = f->header.e_shnum++;
	struct obj_section *sec;

	f->sections = xrealloc(f->sections, (newidx + 1) * sizeof(sec));
	f->sections[newidx] = sec = arch_new_section();

	memset(sec, 0, sizeof(*sec));
	sec->header.sh_type = SHT_PROGBITS;
	sec->header.sh_flags = SHF_WRITE | SHF_ALLOC;
	sec->header.sh_size = size;
	sec->header.sh_addralign = align;
	sec->name = name;
	sec->idx = newidx;
	if (size)
		sec->contents = xmalloc(size);

	sec->load_next = f->load_order;
	f->load_order = sec;
	if (f->load_order_search_start == &f->load_order)
		f->load_order_search_start = &sec->load_next;

	return sec;
}

static void *obj_extend_section(struct obj_section *sec, unsigned long more)
{
	unsigned long oldsize = sec->header.sh_size;
	if (more) { 
		sec->contents = xrealloc(sec->contents, sec->header.sh_size += more);
	}
	return sec->contents + oldsize;
}


/* Conditionally add the symbols from the given symbol set to the
   new module.  */

static int
add_symbols_from(
				 struct obj_file *f,
				 int idx, struct new_module_symbol *syms, size_t nsyms)
{
	struct new_module_symbol *s;
	size_t i;
	int used = 0;
#ifdef SYMBOL_PREFIX
	char *name_buf = 0;
	size_t name_alloced_size = 0;
#endif

	for (i = 0, s = syms; i < nsyms; ++i, ++s) {
		/* Only add symbols that are already marked external.
		   If we override locals we may cause problems for
		   argument initialization.  We will also create a false
		   dependency on the module.  */
		struct obj_symbol *sym;
		char *name = (char *)s->name;

#ifdef SYMBOL_PREFIX
		/* Prepend SYMBOL_PREFIX to the symbol's name (the
		   kernel exports `C names', but module object files
		   reference `linker names').  */
		size_t extra = sizeof SYMBOL_PREFIX;
		size_t name_size = strlen (name) + extra;
		if (name_size > name_alloced_size) {
			name_alloced_size = name_size * 2;
			name_buf = alloca (name_alloced_size);
		}
		strcpy (name_buf, SYMBOL_PREFIX);
		strcpy (name_buf + extra - 1, name);
		name = name_buf;
#endif /* SYMBOL_PREFIX */

		sym = obj_find_symbol(f, name);
		if (sym && !(ELFW(ST_BIND) (sym->info) == STB_LOCAL)) {
#ifdef SYMBOL_PREFIX
			/* Put NAME_BUF into more permanent storage.  */
			name = xmalloc (name_size);
			strcpy (name, name_buf);
#endif
			sym = obj_add_symbol(f, name, -1,
					     ELFW(ST_INFO) (STB_GLOBAL,
							    STT_NOTYPE),
					     idx, s->value, 0);
			/* Did our symbol just get installed?  If so, mark the
			   module as "used".  */
			if (sym->secidx == idx)
				used = 1;
		}
	}

	return used;
}

static void add_kernel_symbols(struct obj_file *f)
{
	struct external_module *m;
	int i, nused = 0;

	/* Add module symbols first.  */

	for (i = 0, m = ext_modules; i < n_ext_modules; ++i, ++m)
		if (m->nsyms
			&& add_symbols_from(f, SHN_HIRESERVE + 2 + i, m->syms,
								m->nsyms)) m->used = 1, ++nused;

	n_ext_modules_used = nused;

	/* And finally the symbols from the kernel proper.  */

	if (nksyms)
		add_symbols_from(f, SHN_HIRESERVE + 1, ksyms, nksyms);
}

static char *get_modinfo_value(struct obj_file *f, const char *key)
{
	struct obj_section *sec;
	char *p, *v, *n, *ep;
	size_t klen = strlen(key);

	sec = obj_find_section(f, ".modinfo");
	if (sec == NULL)
		return NULL;
	p = sec->contents;
	ep = p + sec->header.sh_size;
	while (p < ep) {
		v = strchr(p, '=');
		n = strchr(p, '\0');
		if (v) {
			if (p + klen == v && strncmp(p, key, klen) == 0)
				return v + 1;
		} else {
			if (p + klen == n && strcmp(p, key) == 0)
				return n;
		}
		p = n + 1;
	}

	return NULL;
}


/*======================================================================*/
/* Functions relating to module loading in pre 2.1 kernels.  */

static int
old_process_module_arguments(struct obj_file *f, int argc, char **argv)
{
	while (argc > 0) {
		char *p, *q;
		struct obj_symbol *sym;
		int *loc;

		p = *argv;
		if ((q = strchr(p, '=')) == NULL) {
			argc--;
			continue;
                }
		*q++ = '\0';

		sym = obj_find_symbol(f, p);

		/* Also check that the parameter was not resolved from the kernel.  */
		if (sym == NULL || sym->secidx > SHN_HIRESERVE) {
			error_msg("symbol for parameter %s not found", p);
			return 0;
		}

		loc = (int *) (f->sections[sym->secidx]->contents + sym->value);

		/* Do C quoting if we begin with a ".  */
		if (*q == '"') {
			char *r, *str;

			str = alloca(strlen(q));
			for (r = str, q++; *q != '"'; ++q, ++r) {
				if (*q == '\0') {
					error_msg("improperly terminated string argument for %s", p);
					return 0;
				} else if (*q == '\\')
					switch (*++q) {
					case 'a':
						*r = '\a';
						break;
					case 'b':
						*r = '\b';
						break;
					case 'e':
						*r = '\033';
						break;
					case 'f':
						*r = '\f';
						break;
					case 'n':
						*r = '\n';
						break;
					case 'r':
						*r = '\r';
						break;
					case 't':
						*r = '\t';
						break;

					case '0':
					case '1':
					case '2':
					case '3':
					case '4':
					case '5':
					case '6':
					case '7':
						{
							int c = *q - '0';
							if (q[1] >= '0' && q[1] <= '7') {
								c = (c * 8) + *++q - '0';
								if (q[1] >= '0' && q[1] <= '7')
									c = (c * 8) + *++q - '0';
							}
							*r = c;
						}
						break;

					default:
						*r = *q;
						break;
				} else
					*r = *q;
			}
			*r = '\0';
			obj_string_patch(f, sym->secidx, sym->value, str);
		} else if (*q >= '0' && *q <= '9') {
			do
				*loc++ = strtoul(q, &q, 0);
			while (*q++ == ',');
		} else {
			char *contents = f->sections[sym->secidx]->contents;
			char *myloc = contents + sym->value;
			char *r;			/* To search for commas */

			/* Break the string with comas */
			while ((r = strchr(q, ',')) != (char *) NULL) {
				*r++ = '\0';
				obj_string_patch(f, sym->secidx, myloc - contents, q);
				myloc += sizeof(char *);
				q = r;
			}

			/* last part */
			obj_string_patch(f, sym->secidx, myloc - contents, q);
		}

		argc--, argv++;
	}

	return 1;
}

#ifdef CONFIG_FEATURE_INSMOD_VERSION_CHECKING
static int old_is_module_checksummed(struct obj_file *f)
{
	return obj_find_symbol(f, "Using_Versions") != NULL;
}
/* Get the module's kernel version in the canonical integer form.  */

static int
old_get_module_version(struct obj_file *f, char str[STRVERSIONLEN])
{
	struct obj_symbol *sym;
	char *p, *q;
	int a, b, c;

	sym = obj_find_symbol(f, "kernel_version");
	if (sym == NULL)
		return -1;

	p = f->sections[sym->secidx]->contents + sym->value;
	safe_strncpy(str, p, STRVERSIONLEN);

	a = strtoul(p, &p, 10);
	if (*p != '.')
		return -1;
	b = strtoul(p + 1, &p, 10);
	if (*p != '.')
		return -1;
	c = strtoul(p + 1, &q, 10);
	if (p + 1 == q)
		return -1;

	return a << 16 | b << 8 | c;
}

#endif   /* CONFIG_FEATURE_INSMOD_VERSION_CHECKING */

#ifdef CONFIG_FEATURE_OLD_MODULE_INTERFACE

/* Fetch all the symbols and divvy them up as appropriate for the modules.  */

static int old_get_kernel_symbols(const char *m_name)
{
	struct old_kernel_sym *ks, *k;
	struct new_module_symbol *s;
	struct external_module *mod;
	int nks, nms, nmod, i;

	nks = get_kernel_syms(NULL);
	if (nks <= 0) {
		if (nks)
			perror_msg("get_kernel_syms: %s", m_name);
		else
			error_msg("No kernel symbols");
		return 0;
	}

	ks = k = xmalloc(nks * sizeof(*ks));

	if (get_kernel_syms(ks) != nks) {
		perror("inconsistency with get_kernel_syms -- is someone else "
			   "playing with modules?");
		free(ks);
		return 0;
	}

	/* Collect the module information.  */

	mod = NULL;
	nmod = -1;

	while (k->name[0] == '#' && k->name[1]) {
		struct old_kernel_sym *k2;

		/* Find out how many symbols this module has.  */
		for (k2 = k + 1; k2->name[0] != '#'; ++k2)
			continue;
		nms = k2 - k - 1;

		mod = xrealloc(mod, (++nmod + 1) * sizeof(*mod));
		mod[nmod].name = k->name + 1;
		mod[nmod].addr = k->value;
		mod[nmod].used = 0;
		mod[nmod].nsyms = nms;
		mod[nmod].syms = s = (nms ? xmalloc(nms * sizeof(*s)) : NULL);

		for (i = 0, ++k; i < nms; ++i, ++s, ++k) {
			s->name = (unsigned long) k->name;
			s->value = k->value;
		}

		k = k2;
	}

	ext_modules = mod;
	n_ext_modules = nmod + 1;

	/* Now collect the symbols for the kernel proper.  */

	if (k->name[0] == '#')
		++k;

	nksyms = nms = nks - (k - ks);
	ksyms = s = (nms ? xmalloc(nms * sizeof(*s)) : NULL);

	for (i = 0; i < nms; ++i, ++s, ++k) {
		s->name = (unsigned long) k->name;
		s->value = k->value;
	}

	return 1;
}

/* Return the kernel symbol checksum version, or zero if not used.  */

static int old_is_kernel_checksummed(void)
{
	/* Using_Versions is the first symbol.  */
	if (nksyms > 0
		&& strcmp((char *) ksyms[0].name,
				  "Using_Versions") == 0) return ksyms[0].value;
	else
		return 0;
}


static int old_create_mod_use_count(struct obj_file *f)
{
	struct obj_section *sec;

	sec = obj_create_alloced_section_first(f, ".moduse", sizeof(long),
										   sizeof(long));

	obj_add_symbol(f, "mod_use_count_", -1,
				   ELFW(ST_INFO) (STB_LOCAL, STT_OBJECT), sec->idx, 0,
				   sizeof(long));

	return 1;
}

static int
old_init_module(const char *m_name, struct obj_file *f,
				unsigned long m_size)
{
	char *image;
	struct old_mod_routines routines;
	struct old_symbol_table *symtab;
	int ret;

	/* Create the symbol table */
	{
		int nsyms = 0, strsize = 0, total;

		/* Size things first... */
		if (flag_export) {
			int i;
			for (i = 0; i < HASH_BUCKETS; ++i) {
				struct obj_symbol *sym;
				for (sym = f->symtab[i]; sym; sym = sym->next)
					if (ELFW(ST_BIND) (sym->info) != STB_LOCAL
						&& sym->secidx <= SHN_HIRESERVE) 
					{
						sym->ksymidx = nsyms++;
						strsize += strlen(sym->name) + 1;
					}
			}
		}

		total = (sizeof(struct old_symbol_table)
				 + nsyms * sizeof(struct old_module_symbol)
				 + n_ext_modules_used * sizeof(struct old_module_ref)
				 + strsize);
		symtab = xmalloc(total);
		symtab->size = total;
		symtab->n_symbols = nsyms;
		symtab->n_refs = n_ext_modules_used;

		if (flag_export && nsyms) {
			struct old_module_symbol *ksym;
			char *str;
			int i;

			ksym = symtab->symbol;
			str = ((char *) ksym + nsyms * sizeof(struct old_module_symbol)
				   + n_ext_modules_used * sizeof(struct old_module_ref));

			for (i = 0; i < HASH_BUCKETS; ++i) {
				struct obj_symbol *sym;
				for (sym = f->symtab[i]; sym; sym = sym->next)
					if (sym->ksymidx >= 0) {
						ksym->addr = obj_symbol_final_value(f, sym);
						ksym->name =
							(unsigned long) str - (unsigned long) symtab;

						strcpy(str, sym->name);
						str += strlen(sym->name) + 1;
						ksym++;
					}
			}
		}

		if (n_ext_modules_used) {
			struct old_module_ref *ref;
			int i;

			ref = (struct old_module_ref *)
				((char *) symtab->symbol + nsyms * sizeof(struct old_module_symbol));