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Commit 8931360e authored by Russell King's avatar Russell King
Browse files

ARM: module: clean up handling of ELF unwind tables 



There's no need to keep pointers to the ELF sections available while
the module is loaded - we only need the section pointers while we're
finding and registering the unwind tables, which can all be done during
the finalize stage of loading.

Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
parent f6614b7b

arch/arm/include/asm/module.h

+5 −10
Original line number Diff line number Diff line
@@ -8,11 +8,6 @@ 
struct unwind_table;



#ifdef CONFIG_ARM_UNWIND

struct arm_unwind_mapping {

	Elf_Shdr *unw_sec;

	Elf_Shdr *sec_text;

	struct unwind_table *unwind;

};

enum {

	ARM_SEC_INIT,

	ARM_SEC_DEVINIT,
@@ -21,13 +16,13 @@ enum { 
	ARM_SEC_DEVEXIT,

	ARM_SEC_MAX,

};

#endif



struct mod_arch_specific {

	struct arm_unwind_mapping map[ARM_SEC_MAX];

};

#else

struct mod_arch_specific {

};

#ifdef CONFIG_ARM_UNWIND

	struct unwind_table *unwind[ARM_SEC_MAX];

#endif

};



/*

 * Include the ARM architecture version.

arch/arm/kernel/module.c

+51 −55
Original line number Diff line number Diff line
@@ -67,35 +67,6 @@ int module_frob_arch_sections(Elf_Ehdr *hdr, 
			      char *secstrings,

			      struct module *mod)

{

#ifdef CONFIG_ARM_UNWIND

	Elf_Shdr *s, *sechdrs_end = sechdrs + hdr->e_shnum;

	struct arm_unwind_mapping *maps = mod->arch.map;



	for (s = sechdrs; s < sechdrs_end; s++) {

		char const *secname = secstrings + s->sh_name;



		if (strcmp(".ARM.exidx.init.text", secname) == 0)

			maps[ARM_SEC_INIT].unw_sec = s;

		else if (strcmp(".ARM.exidx.devinit.text", secname) == 0)

			maps[ARM_SEC_DEVINIT].unw_sec = s;

		else if (strcmp(".ARM.exidx", secname) == 0)

			maps[ARM_SEC_CORE].unw_sec = s;

		else if (strcmp(".ARM.exidx.exit.text", secname) == 0)

			maps[ARM_SEC_EXIT].unw_sec = s;

		else if (strcmp(".ARM.exidx.devexit.text", secname) == 0)

			maps[ARM_SEC_DEVEXIT].unw_sec = s;

		else if (strcmp(".init.text", secname) == 0)

			maps[ARM_SEC_INIT].sec_text = s;

		else if (strcmp(".devinit.text", secname) == 0)

			maps[ARM_SEC_DEVINIT].sec_text = s;

		else if (strcmp(".text", secname) == 0)

			maps[ARM_SEC_CORE].sec_text = s;

		else if (strcmp(".exit.text", secname) == 0)

			maps[ARM_SEC_EXIT].sec_text = s;

		else if (strcmp(".devexit.text", secname) == 0)

			maps[ARM_SEC_DEVEXIT].sec_text = s;

	}

#endif

	return 0;

}
@@ -300,41 +271,66 @@ apply_relocate_add(Elf32_Shdr *sechdrs, const char *strtab, 
	return -ENOEXEC;

}



#ifdef CONFIG_ARM_UNWIND

static void register_unwind_tables(struct module *mod)

struct mod_unwind_map {

	const Elf_Shdr *unw_sec;

	const Elf_Shdr *txt_sec;

};



int module_finalize(const Elf32_Ehdr *hdr, const Elf_Shdr *sechdrs,

		    struct module *mod)

{

#ifdef CONFIG_ARM_UNWIND

	const char *secstrs = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;

	const Elf_Shdr *s, *sechdrs_end = sechdrs + hdr->e_shnum;

	struct mod_unwind_map maps[ARM_SEC_MAX];

	int i;

	for (i = 0; i < ARM_SEC_MAX; ++i) {

		struct arm_unwind_mapping *map = &mod->arch.map[i];

		if (map->unw_sec && map->sec_text)

			map->unwind = unwind_table_add(map->unw_sec->sh_addr,

						       map->unw_sec->sh_size,

						       map->sec_text->sh_addr,

						       map->sec_text->sh_size);

	}

}



static void unregister_unwind_tables(struct module *mod)

{

	int i = ARM_SEC_MAX;

	while (--i >= 0)

		unwind_table_del(mod->arch.map[i].unwind);

	memset(maps, 0, sizeof(maps));



	for (s = sechdrs; s < sechdrs_end; s++) {

		const char *secname = secstrs + s->sh_name;



		if (strcmp(".ARM.exidx.init.text", secname) == 0)

			maps[ARM_SEC_INIT].unw_sec = s;

		else if (strcmp(".ARM.exidx.devinit.text", secname) == 0)

			maps[ARM_SEC_DEVINIT].unw_sec = s;

		else if (strcmp(".ARM.exidx", secname) == 0)

			maps[ARM_SEC_CORE].unw_sec = s;

		else if (strcmp(".ARM.exidx.exit.text", secname) == 0)

			maps[ARM_SEC_EXIT].unw_sec = s;

		else if (strcmp(".ARM.exidx.devexit.text", secname) == 0)

			maps[ARM_SEC_DEVEXIT].unw_sec = s;

		else if (strcmp(".init.text", secname) == 0)

			maps[ARM_SEC_INIT].txt_sec = s;

		else if (strcmp(".devinit.text", secname) == 0)

			maps[ARM_SEC_DEVINIT].txt_sec = s;

		else if (strcmp(".text", secname) == 0)

			maps[ARM_SEC_CORE].txt_sec = s;

		else if (strcmp(".exit.text", secname) == 0)

			maps[ARM_SEC_EXIT].txt_sec = s;

		else if (strcmp(".devexit.text", secname) == 0)

			maps[ARM_SEC_DEVEXIT].txt_sec = s;

	}

#else

static inline void register_unwind_tables(struct module *mod) { }

static inline void unregister_unwind_tables(struct module *mod) { }

#endif



int

module_finalize(const Elf32_Ehdr *hdr, const Elf_Shdr *sechdrs,

		struct module *module)

{

	register_unwind_tables(module);

	for (i = 0; i < ARM_SEC_MAX; i++)

		if (maps[i].unw_sec && maps[i].txt_sec)

			mod->arch.unwind[i] =

				unwind_table_add(maps[i].unw_sec->sh_addr,

					         maps[i].unw_sec->sh_size,

					         maps[i].txt_sec->sh_addr,

					         maps[i].txt_sec->sh_size);

#endif

	return 0;

}



void

module_arch_cleanup(struct module *mod)

{

	unregister_unwind_tables(mod);

#ifdef CONFIG_ARM_UNWIND

	int i;



	for (i = 0; i < ARM_SEC_MAX; i++)

		if (mod->arch.unwind[i])

			unwind_table_del(mod->arch.unwind[i]);

#endif

}