Commit 25eac74b authored by Josh Poimboeuf's avatar Josh Poimboeuf
Browse files

objtool: Add section/symbol type helpers 



Add some helper macros to improve readability.

Acked-by: default avatarPetr Mladek <pmladek@suse.com>
Tested-by: default avatarJoe Lawrence <joe.lawrence@redhat.com>
Signed-off-by: default avatarJosh Poimboeuf <jpoimboe@kernel.org>
parent 96eceff3

tools/objtool/arch/x86/special.c

+1 −1
Original line number Diff line number Diff line
@@ -89,7 +89,7 @@ struct reloc *arch_find_switch_table(struct objtool_file *file, 
	/* look for a relocation which references .rodata */

	text_reloc = find_reloc_by_dest_range(file->elf, insn->sec,

					      insn->offset, insn->len);

	if (!text_reloc || text_reloc->sym->type != STT_SECTION ||

	if (!text_reloc || !is_sec_sym(text_reloc->sym) ||

	    !text_reloc->sym->sec->rodata)

		return NULL;

tools/objtool/check.c

+29 −29
Original line number Diff line number Diff line
@@ -261,7 +261,7 @@ static bool __dead_end_function(struct objtool_file *file, struct symbol *func, 
	if (!func)

		return false;



	if (func->bind == STB_GLOBAL || func->bind == STB_WEAK) {

	if (!is_local_sym(func)) {

		if (is_rust_noreturn(func))

			return true;
@@ -270,7 +270,7 @@ static bool __dead_end_function(struct objtool_file *file, struct symbol *func, 
				return true;

	}



	if (func->bind == STB_WEAK)

	if (is_weak_sym(func))

		return false;



	if (!func->len)
@@ -436,7 +436,7 @@ static int decode_instructions(struct objtool_file *file) 
		u8 prev_len = 0;

		u8 idx = 0;



		if (!(sec->sh.sh_flags & SHF_EXECINSTR))

		if (!is_text_sec(sec))

			continue;



		if (strcmp(sec->name, ".altinstr_replacement") &&
@@ -459,7 +459,7 @@ static int decode_instructions(struct objtool_file *file) 
		if (!strcmp(sec->name, ".init.text") && !opts.module)

			sec->init = true;



		for (offset = 0; offset < sec->sh.sh_size; offset += insn->len) {

		for (offset = 0; offset < sec_size(sec); offset += insn->len) {

			if (!insns || idx == INSN_CHUNK_MAX) {

				insns = calloc(INSN_CHUNK_SIZE, sizeof(*insn));

				if (!insns) {
@@ -478,7 +478,7 @@ static int decode_instructions(struct objtool_file *file) 
			insn->offset = offset;

			insn->prev_len = prev_len;



			if (arch_decode_instruction(file, sec, offset, sec->sh.sh_size - offset, insn))

			if (arch_decode_instruction(file, sec, offset, sec_size(sec) - offset, insn))

				return -1;



			prev_len = insn->len;
@@ -496,12 +496,12 @@ static int decode_instructions(struct objtool_file *file) 
		}



		sec_for_each_sym(sec, func) {

			if (func->type != STT_NOTYPE && func->type != STT_FUNC)

			if (!is_notype_sym(func) && !is_func_sym(func))

				continue;



			if (func->offset == sec->sh.sh_size) {

			if (func->offset == sec_size(sec)) {

				/* Heuristic: likely an "end" symbol */

				if (func->type == STT_NOTYPE)

				if (is_notype_sym(func))

					continue;

				ERROR("%s(): STT_FUNC at end of section", func->name);

				return -1;
@@ -517,7 +517,7 @@ static int decode_instructions(struct objtool_file *file) 


			sym_for_each_insn(file, func, insn) {

				insn->sym = func;

				if (func->type == STT_FUNC &&

				if (is_func_sym(func) &&

				    insn->type == INSN_ENDBR &&

				    list_empty(&insn->call_node)) {

					if (insn->offset == func->offset) {
@@ -561,7 +561,7 @@ static int add_pv_ops(struct objtool_file *file, const char *symname) 
		idx = (reloc_offset(reloc) - sym->offset) / sizeof(unsigned long);



		func = reloc->sym;

		if (func->type == STT_SECTION)

		if (is_sec_sym(func))

			func = find_symbol_by_offset(reloc->sym->sec,

						     reloc_addend(reloc));

		if (!func) {
@@ -823,7 +823,7 @@ static int create_ibt_endbr_seal_sections(struct objtool_file *file) 
		struct symbol *sym = insn->sym;

		*site = 0;



		if (opts.module && sym && sym->type == STT_FUNC &&

		if (opts.module && sym && is_func_sym(sym) &&

		    insn->offset == sym->offset &&

		    (!strcmp(sym->name, "init_module") ||

		     !strcmp(sym->name, "cleanup_module"))) {
@@ -858,7 +858,7 @@ static int create_cfi_sections(struct objtool_file *file) 


	idx = 0;

	for_each_sym(file->elf, sym) {

		if (sym->type != STT_FUNC)

		if (!is_func_sym(sym))

			continue;



		if (strncmp(sym->name, "__cfi_", 6))
@@ -874,7 +874,7 @@ static int create_cfi_sections(struct objtool_file *file) 


	idx = 0;

	for_each_sym(file->elf, sym) {

		if (sym->type != STT_FUNC)

		if (!is_func_sym(sym))

			continue;



		if (strncmp(sym->name, "__cfi_", 6))
@@ -1463,7 +1463,7 @@ static bool jump_is_sibling_call(struct objtool_file *file, 
		return false;



	/* Disallow sibling calls into STT_NOTYPE */

	if (ts->type == STT_NOTYPE)

	if (is_notype_sym(ts))

		return false;



	/* Must not be self to be a sibling */
@@ -1497,7 +1497,7 @@ static int add_jump_destinations(struct objtool_file *file) 
		if (!reloc) {

			dest_sec = insn->sec;

			dest_off = arch_jump_destination(insn);

		} else if (reloc->sym->type == STT_SECTION) {

		} else if (is_sec_sym(reloc->sym)) {

			dest_sec = reloc->sym->sec;

			dest_off = arch_insn_adjusted_addend(insn, reloc);

		} else if (reloc->sym->retpoline_thunk) {
@@ -1657,12 +1657,12 @@ static int add_call_destinations(struct objtool_file *file) 
				return -1;

			}



			if (func && insn_call_dest(insn)->type != STT_FUNC) {

			if (func && !is_func_sym(insn_call_dest(insn))) {

				ERROR_INSN(insn, "unsupported call to non-function");

				return -1;

			}



		} else if (reloc->sym->type == STT_SECTION) {

		} else if (is_sec_sym(reloc->sym)) {

			dest_off = arch_insn_adjusted_addend(insn, reloc);

			dest = find_call_destination(reloc->sym->sec, dest_off);

			if (!dest) {
@@ -2146,7 +2146,7 @@ static int add_jump_table_alts(struct objtool_file *file) 
		return 0;



	for_each_sym(file->elf, func) {

		if (func->type != STT_FUNC)

		if (!is_func_sym(func))

			continue;



		mark_func_jump_tables(file, func);
@@ -2185,14 +2185,14 @@ static int read_unwind_hints(struct objtool_file *file) 
		return -1;

	}



	if (sec->sh.sh_size % sizeof(struct unwind_hint)) {

	if (sec_size(sec) % sizeof(struct unwind_hint)) {

		ERROR("struct unwind_hint size mismatch");

		return -1;

	}



	file->hints = true;



	for (i = 0; i < sec->sh.sh_size / sizeof(struct unwind_hint); i++) {

	for (i = 0; i < sec_size(sec) / sizeof(struct unwind_hint); i++) {

		hint = (struct unwind_hint *)sec->data->d_buf + i;



		reloc = find_reloc_by_dest(file->elf, sec, i * sizeof(*hint));
@@ -2201,7 +2201,7 @@ static int read_unwind_hints(struct objtool_file *file) 
			return -1;

		}



		if (reloc->sym->type == STT_SECTION) {

		if (is_sec_sym(reloc->sym)) {

			offset = reloc_addend(reloc);

		} else if (reloc->sym->local_label) {

			offset = reloc->sym->offset;
@@ -2237,7 +2237,7 @@ static int read_unwind_hints(struct objtool_file *file) 
		if (hint->type == UNWIND_HINT_TYPE_REGS_PARTIAL) {

			struct symbol *sym = find_symbol_by_offset(insn->sec, insn->offset);



			if (sym && sym->bind == STB_GLOBAL) {

			if (sym && is_global_sym(sym)) {

				if (opts.ibt && insn->type != INSN_ENDBR && !insn->noendbr) {

					ERROR_INSN(insn, "UNWIND_HINT_IRET_REGS without ENDBR");

					return -1;
@@ -2452,10 +2452,10 @@ static int classify_symbols(struct objtool_file *file) 
	struct symbol *func;



	for_each_sym(file->elf, func) {

		if (func->type == STT_NOTYPE && strstarts(func->name, ".L"))

		if (is_notype_sym(func) && strstarts(func->name, ".L"))

			func->local_label = true;



		if (func->bind != STB_GLOBAL)

		if (!is_global_sym(func))

			continue;



		if (!strncmp(func->name, STATIC_CALL_TRAMP_PREFIX_STR,
@@ -4179,11 +4179,11 @@ static int add_prefix_symbols(struct objtool_file *file) 
	struct symbol *func;



	for_each_sec(file->elf, sec) {

		if (!(sec->sh.sh_flags & SHF_EXECINSTR))

		if (!is_text_sec(sec))

			continue;



		sec_for_each_sym(sec, func) {

			if (func->type != STT_FUNC)

			if (!is_func_sym(func))

				continue;



			add_prefix_symbol(file, func);
@@ -4227,7 +4227,7 @@ static int validate_section(struct objtool_file *file, struct section *sec) 
	int warnings = 0;



	sec_for_each_sym(sec, func) {

		if (func->type != STT_FUNC)

		if (!is_func_sym(func))

			continue;



		init_insn_state(file, &state, sec);
@@ -4271,7 +4271,7 @@ static int validate_functions(struct objtool_file *file) 
	int warnings = 0;



	for_each_sec(file->elf, sec) {

		if (!(sec->sh.sh_flags & SHF_EXECINSTR))

		if (!is_text_sec(sec))

			continue;



		warnings += validate_section(file, sec);
@@ -4452,7 +4452,7 @@ static int validate_ibt(struct objtool_file *file) 
	for_each_sec(file->elf, sec) {



		/* Already done by validate_ibt_insn() */

		if (sec->sh.sh_flags & SHF_EXECINSTR)

		if (is_text_sec(sec))

			continue;



		if (!sec->rsec)

tools/objtool/elf.c

+10 −10
Original line number Diff line number Diff line
@@ -170,7 +170,7 @@ struct symbol *find_symbol_by_offset(struct section *sec, unsigned long offset) 
	struct symbol *iter;



	__sym_for_each(iter, tree, offset, offset) {

		if (iter->offset == offset && iter->type != STT_SECTION)

		if (iter->offset == offset && !is_sec_sym(iter))

			return iter;

	}
@@ -183,7 +183,7 @@ struct symbol *find_func_by_offset(struct section *sec, unsigned long offset) 
	struct symbol *iter;



	__sym_for_each(iter, tree, offset, offset) {

		if (iter->offset == offset && iter->type == STT_FUNC)

		if (iter->offset == offset && is_func_sym(iter))

			return iter;

	}
@@ -264,7 +264,7 @@ struct symbol *find_func_containing(struct section *sec, unsigned long offset) 
	struct symbol *iter;



	__sym_for_each(iter, tree, offset, offset) {

		if (iter->type == STT_FUNC)

		if (is_func_sym(iter))

			return iter;

	}
@@ -373,14 +373,14 @@ static int read_sections(struct elf *elf) 
			return -1;

		}



		if (sec->sh.sh_size != 0 && !is_dwarf_section(sec)) {

		if (sec_size(sec) != 0 && !is_dwarf_section(sec)) {

			sec->data = elf_getdata(s, NULL);

			if (!sec->data) {

				ERROR_ELF("elf_getdata");

				return -1;

			}

			if (sec->data->d_off != 0 ||

			    sec->data->d_size != sec->sh.sh_size) {

			    sec->data->d_size != sec_size(sec)) {

				ERROR("unexpected data attributes for %s", sec->name);

				return -1;

			}
@@ -420,7 +420,7 @@ static void elf_add_symbol(struct elf *elf, struct symbol *sym) 
	sym->type = GELF_ST_TYPE(sym->sym.st_info);

	sym->bind = GELF_ST_BIND(sym->sym.st_info);



	if (sym->type == STT_FILE)

	if (is_file_sym(sym))

		elf->num_files++;



	sym->offset = sym->sym.st_value;
@@ -527,7 +527,7 @@ static int read_symbols(struct elf *elf) 
		sec_for_each_sym(sec, sym) {

			char *pname;

			size_t pnamelen;

			if (sym->type != STT_FUNC)

			if (!is_func_sym(sym))

				continue;



			if (sym->pfunc == NULL)
@@ -929,7 +929,7 @@ struct reloc *elf_init_reloc_text_sym(struct elf *elf, struct section *sec, 
	struct symbol *sym = insn_sec->sym;

	int addend = insn_off;



	if (!(insn_sec->sh.sh_flags & SHF_EXECINSTR)) {

	if (!is_text_sec(insn_sec)) {

		ERROR("bad call to %s() for data symbol %s", __func__, sym->name);

		return NULL;

	}
@@ -958,7 +958,7 @@ struct reloc *elf_init_reloc_data_sym(struct elf *elf, struct section *sec, 
				      struct symbol *sym,

				      s64 addend)

{

	if (sym->sec && (sec->sh.sh_flags & SHF_EXECINSTR)) {

	if (is_text_sec(sec)) {

		ERROR("bad call to %s() for text symbol %s", __func__, sym->name);

		return NULL;

	}
@@ -1287,7 +1287,7 @@ int elf_write_insn(struct elf *elf, struct section *sec, 
 */

static int elf_truncate_section(struct elf *elf, struct section *sec)

{

	u64 size = sec->sh.sh_size;

	u64 size = sec_size(sec);

	bool truncated = false;

	Elf_Data *data = NULL;

	Elf_Scn *s;

tools/objtool/include/objtool/elf.h

+66 −0
Original line number Diff line number Diff line
@@ -8,6 +8,7 @@ 


#include <stdio.h>

#include <gelf.h>

#include <linux/string.h>

#include <linux/list.h>

#include <linux/hashtable.h>

#include <linux/rbtree.h>
@@ -178,11 +179,71 @@ static inline unsigned int elf_text_rela_type(struct elf *elf) 
	return elf_addr_size(elf) == 4 ? R_TEXT32 : R_TEXT64;

}



static inline bool sym_has_sec(struct symbol *sym)

{

	return sym->sec->idx;

}



static inline bool is_null_sym(struct symbol *sym)

{

	return !sym->idx;

}



static inline bool is_sec_sym(struct symbol *sym)

{

	return sym->type == STT_SECTION;

}



static inline bool is_object_sym(struct symbol *sym)

{

	return sym->type == STT_OBJECT;

}



static inline bool is_func_sym(struct symbol *sym)

{

	return sym->type == STT_FUNC;

}



static inline bool is_file_sym(struct symbol *sym)

{

	return sym->type == STT_FILE;

}



static inline bool is_notype_sym(struct symbol *sym)

{

	return sym->type == STT_NOTYPE;

}



static inline bool is_global_sym(struct symbol *sym)

{

	return sym->bind == STB_GLOBAL;

}



static inline bool is_weak_sym(struct symbol *sym)

{

	return sym->bind == STB_WEAK;

}



static inline bool is_local_sym(struct symbol *sym)

{

	return sym->bind == STB_LOCAL;

}



static inline bool is_reloc_sec(struct section *sec)

{

	return sec->sh.sh_type == SHT_RELA || sec->sh.sh_type == SHT_REL;

}



static inline bool is_string_sec(struct section *sec)

{

	return sec->sh.sh_flags & SHF_STRINGS;

}



static inline bool is_text_sec(struct section *sec)

{

	return sec->sh.sh_flags & SHF_EXECINSTR;

}



static inline bool sec_changed(struct section *sec)

{

	return sec->_changed;
@@ -223,6 +284,11 @@ static inline bool is_32bit_reloc(struct reloc *reloc) 
	return reloc->sec->sh.sh_entsize < 16;

}



static inline unsigned long sec_size(struct section *sec)

{

	return sec->sh.sh_size;

}



#define __get_reloc_field(reloc, field)					\

({									\

	is_32bit_reloc(reloc) ?						\

tools/objtool/special.c

+2 −2
Original line number Diff line number Diff line
@@ -142,12 +142,12 @@ int special_get_alts(struct elf *elf, struct list_head *alts) 
		if (!sec)

			continue;



		if (sec->sh.sh_size % entry->size != 0) {

		if (sec_size(sec) % entry->size != 0) {

			ERROR("%s size not a multiple of %d", sec->name, entry->size);

			return -1;

		}



		nr_entries = sec->sh.sh_size / entry->size;

		nr_entries = sec_size(sec) / entry->size;



		for (idx = 0; idx < nr_entries; idx++) {

			alt = malloc(sizeof(*alt));