Commit be2f0b1e authored by Josh Poimboeuf's avatar Josh Poimboeuf
Browse files

objtool: Get rid of reloc->jump_table_start 

Rework the jump table logic slightly so 'jump_table_start' is no longer
needed.

With allyesconfig + CONFIG_DEBUG_INFO:

- Before: peak heap memory consumption: 40.37G
- After:  peak heap memory consumption: 38.64G

Link: https://lore.kernel.org/r/e1602ed8a6171ada3cfac0bd8449892ec82bd188.1685464332.git.jpoimboe@kernel.org


Signed-off-by: default avatarJosh Poimboeuf <jpoimboe@kernel.org>
parent 0696b6e3

tools/objtool/check.c

+23 −12
Original line number Diff line number Diff line
@@ -1989,13 +1989,14 @@ static int add_special_section_alts(struct objtool_file *file) 
}



static int add_jump_table(struct objtool_file *file, struct instruction *insn,

			    struct reloc *table)

			  struct reloc *next_table)

{

	struct reloc *reloc = table;

	struct instruction *dest_insn;

	struct alternative *alt;

	struct symbol *pfunc = insn_func(insn)->pfunc;

	struct reloc *table = insn_jump_table(insn);

	struct instruction *dest_insn;

	unsigned int prev_offset = 0;

	struct reloc *reloc = table;

	struct alternative *alt;



	/*

	 * Each @reloc is a switch table relocation which points to the target
@@ -2004,7 +2005,7 @@ static int add_jump_table(struct objtool_file *file, struct instruction *insn, 
	for_each_reloc_from(table->sec, reloc) {



		/* Check for the end of the table: */

		if (reloc != table && reloc->jump_table_start)

		if (reloc != table && reloc == next_table)

			break;



		/* Make sure the table entries are consecutive: */
@@ -2119,29 +2120,39 @@ static void mark_func_jump_tables(struct objtool_file *file, 
			continue;



		reloc = find_jump_table(file, func, insn);

		if (reloc) {

			reloc->jump_table_start = true;

		if (reloc)

			insn->_jump_table = reloc;

	}

}

}



static int add_func_jump_tables(struct objtool_file *file,

				  struct symbol *func)

{

	struct instruction *insn;

	int ret;

	struct instruction *insn, *insn_t1 = NULL, *insn_t2;

	int ret = 0;



	func_for_each_insn(file, func, insn) {

		if (!insn_jump_table(insn))

			continue;



		ret = add_jump_table(file, insn, insn_jump_table(insn));

		if (!insn_t1) {

			insn_t1 = insn;

			continue;

		}



		insn_t2 = insn;



		ret = add_jump_table(file, insn_t1, insn_jump_table(insn_t2));

		if (ret)

			return ret;



		insn_t1 = insn_t2;

	}



	return 0;

	if (insn_t1)

		ret = add_jump_table(file, insn_t1, NULL);



	return ret;

}



/*

tools/objtool/include/objtool/elf.h

+0 −1
Original line number Diff line number Diff line
@@ -75,7 +75,6 @@ struct reloc { 
	struct section *sec;

	struct symbol *sym;

	struct list_head sym_reloc_entry;

	bool jump_table_start;

};



struct elf {