Commit 22e268eb authored by Rusty Russell's avatar Rusty Russell
Browse files

module: refactor load_module part 5 



1) Extract out the relocation loop into apply_relocations
2) Extract license and version checks into check_module_license_and_versions
3) Extract icache flushing into flush_module_icache
4) Move __obsparm warning into find_module_sections
5) Move license setting into check_modinfo.

Signed-off-by: default avatarRusty Russell <rusty@rustcorp.com.au>
parent 9f85a4bb

kernel/module.c

+106 −76
Original line number Diff line number Diff line
@@ -1698,6 +1698,39 @@ static int simplify_symbols(Elf_Shdr *sechdrs, 
	return ret;

}



static int apply_relocations(struct module *mod,

			     Elf_Ehdr *hdr,

			     Elf_Shdr *sechdrs,

			     unsigned int symindex,

			     unsigned int strindex)

{

	unsigned int i;

	int err = 0;



	/* Now do relocations. */

	for (i = 1; i < hdr->e_shnum; i++) {

		const char *strtab = (char *)sechdrs[strindex].sh_addr;

		unsigned int info = sechdrs[i].sh_info;



		/* Not a valid relocation section? */

		if (info >= hdr->e_shnum)

			continue;



		/* Don't bother with non-allocated sections */

		if (!(sechdrs[info].sh_flags & SHF_ALLOC))

			continue;



		if (sechdrs[i].sh_type == SHT_REL)

			err = apply_relocate(sechdrs, strtab, symindex, i, mod);

		else if (sechdrs[i].sh_type == SHT_RELA)

			err = apply_relocate_add(sechdrs, strtab, symindex, i,

						 mod);

		if (err < 0)

			break;

	}

	return err;

}



/* Additional bytes needed by arch in front of individual sections */

unsigned int __weak arch_mod_section_prepend(struct module *mod,

					     unsigned int section)
@@ -2179,6 +2212,10 @@ static int check_modinfo(struct module *mod, 
		       " the quality is unknown, you have been warned.\n",

		       mod->name);

	}



	/* Set up license info based on the info section */

	set_license(mod, get_modinfo(sechdrs, infoindex, "license"));



	return 0;

}
@@ -2245,6 +2282,10 @@ static void find_module_sections(struct module *mod, Elf_Ehdr *hdr, 
					     sizeof(*mod->ftrace_callsites),

					     &mod->num_ftrace_callsites);

#endif



	if (section_addr(hdr, sechdrs, secstrings, "__obsparm"))

		printk(KERN_WARNING "%s: Ignoring obsolete parameters\n",

		       mod->name);

}



static struct module *move_module(struct module *mod,
@@ -2311,6 +2352,60 @@ static struct module *move_module(struct module *mod, 
	return mod;

}



static int check_module_license_and_versions(struct module *mod,

					     Elf_Shdr *sechdrs)

{

	/*

	 * ndiswrapper is under GPL by itself, but loads proprietary modules.

	 * Don't use add_taint_module(), as it would prevent ndiswrapper from

	 * using GPL-only symbols it needs.

	 */

	if (strcmp(mod->name, "ndiswrapper") == 0)

		add_taint(TAINT_PROPRIETARY_MODULE);



	/* driverloader was caught wrongly pretending to be under GPL */

	if (strcmp(mod->name, "driverloader") == 0)

		add_taint_module(mod, TAINT_PROPRIETARY_MODULE);



#ifdef CONFIG_MODVERSIONS

	if ((mod->num_syms && !mod->crcs)

	    || (mod->num_gpl_syms && !mod->gpl_crcs)

	    || (mod->num_gpl_future_syms && !mod->gpl_future_crcs)

#ifdef CONFIG_UNUSED_SYMBOLS

	    || (mod->num_unused_syms && !mod->unused_crcs)

	    || (mod->num_unused_gpl_syms && !mod->unused_gpl_crcs)

#endif

		) {

		return try_to_force_load(mod,

					 "no versions for exported symbols");

	}

#endif

	return 0;

}



static void flush_module_icache(const struct module *mod)

{

	mm_segment_t old_fs;



	/* flush the icache in correct context */

	old_fs = get_fs();

	set_fs(KERNEL_DS);



	/*

	 * Flush the instruction cache, since we've played with text.

	 * Do it before processing of module parameters, so the module

	 * can provide parameter accessor functions of its own.

	 */

	if (mod->module_init)

		flush_icache_range((unsigned long)mod->module_init,

				   (unsigned long)mod->module_init

				   + mod->init_size);

	flush_icache_range((unsigned long)mod->module_core,

			   (unsigned long)mod->module_core + mod->core_size);



	set_fs(old_fs);

}



/* Allocate and load the module: note that size of section 0 is always

   zero, and we rely on this for optional sections. */

static noinline struct module *load_module(void __user *umod,
@@ -2331,8 +2426,6 @@ static noinline struct module *load_module(void __user *umod, 
	struct _ddebug *debug = NULL;

	unsigned int num_debug = 0;



	mm_segment_t old_fs;



	DEBUGP("load_module: umod=%p, len=%lu, uargs=%p\n",

	       umod, len, uargs);
@@ -2453,20 +2546,13 @@ static noinline struct module *load_module(void __user *umod, 
	if (err)

		goto free_init;



	/* Set up license info based on the info section */

	set_license(mod, get_modinfo(sechdrs, infoindex, "license"));



	/*

	 * ndiswrapper is under GPL by itself, but loads proprietary modules.

	 * Don't use add_taint_module(), as it would prevent ndiswrapper from

	 * using GPL-only symbols it needs.

	 */

	if (strcmp(mod->name, "ndiswrapper") == 0)

		add_taint(TAINT_PROPRIETARY_MODULE);

	/* Now we've got everything in the final locations, we can

	 * find optional sections. */

	find_module_sections(mod, hdr, sechdrs, secstrings);



	/* driverloader was caught wrongly pretending to be under GPL */

	if (strcmp(mod->name, "driverloader") == 0)

		add_taint_module(mod, TAINT_PROPRIETARY_MODULE);

	err = check_module_license_and_versions(mod, sechdrs);

	if (err)

		goto free_unload;



	/* Set up MODINFO_ATTR fields */

	setup_modinfo(mod, sechdrs, infoindex);
@@ -2477,47 +2563,9 @@ static noinline struct module *load_module(void __user *umod, 
	if (err < 0)

		goto cleanup;



	/* Now we've got everything in the final locations, we can

	 * find optional sections. */

	find_module_sections(mod, hdr, sechdrs, secstrings);



#ifdef CONFIG_MODVERSIONS

	if ((mod->num_syms && !mod->crcs)

	    || (mod->num_gpl_syms && !mod->gpl_crcs)

	    || (mod->num_gpl_future_syms && !mod->gpl_future_crcs)

#ifdef CONFIG_UNUSED_SYMBOLS

	    || (mod->num_unused_syms && !mod->unused_crcs)

	    || (mod->num_unused_gpl_syms && !mod->unused_gpl_crcs)

#endif

		) {

		err = try_to_force_load(mod,

					"no versions for exported symbols");

		if (err)

			goto cleanup;

	}

#endif



	/* Now do relocations. */

	for (i = 1; i < hdr->e_shnum; i++) {

		const char *strtab = (char *)sechdrs[strindex].sh_addr;

		unsigned int info = sechdrs[i].sh_info;



		/* Not a valid relocation section? */

		if (info >= hdr->e_shnum)

			continue;



		/* Don't bother with non-allocated sections */

		if (!(sechdrs[info].sh_flags & SHF_ALLOC))

			continue;



		if (sechdrs[i].sh_type == SHT_REL)

			err = apply_relocate(sechdrs, strtab, symindex, i,mod);

		else if (sechdrs[i].sh_type == SHT_RELA)

			err = apply_relocate_add(sechdrs, strtab, symindex, i,

						 mod);

	err = apply_relocations(mod, hdr, sechdrs, symindex, strindex);

	if (err < 0)

		goto cleanup;

	}



  	/* Set up and sort exception table */

	mod->extable = section_objs(hdr, sechdrs, secstrings, "__ex_table",
@@ -2541,28 +2589,9 @@ static noinline struct module *load_module(void __user *umod, 
	if (err < 0)

		goto cleanup;



	/* flush the icache in correct context */

	old_fs = get_fs();

	set_fs(KERNEL_DS);



	/*

	 * Flush the instruction cache, since we've played with text.

	 * Do it before processing of module parameters, so the module

	 * can provide parameter accessor functions of its own.

	 */

	if (mod->module_init)

		flush_icache_range((unsigned long)mod->module_init,

				   (unsigned long)mod->module_init

				   + mod->init_size);

	flush_icache_range((unsigned long)mod->module_core,

			   (unsigned long)mod->module_core + mod->core_size);



	set_fs(old_fs);

	flush_module_icache(mod);



	mod->args = args;

	if (section_addr(hdr, sechdrs, secstrings, "__obsparm"))

		printk(KERN_WARNING "%s: Ignoring obsolete parameters\n",

		       mod->name);



	/* Now sew it into the lists so we can get lockdep and oops

	 * info during argument parsing.  Noone should access us, since
@@ -2619,6 +2648,7 @@ static noinline struct module *load_module(void __user *umod, 
	module_arch_cleanup(mod);

 cleanup:

	free_modinfo(mod);

 free_unload:

	module_unload_free(mod);

 free_init:

	module_free(mod, mod->module_init);

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