Commit 7bd2a600 authored by Peter Zijlstra's avatar Peter Zijlstra Committed by Ingo Molnar
Browse files

objtool: Cache instruction relocs 



Track the reloc of instructions in the new instruction->reloc field
to avoid having to look them up again later.

( Technically x86 instructions can have two relocations, but not jumps
  and calls, for which we're using this. )

Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
Reviewed-by: default avatarMiroslav Benes <mbenes@suse.cz>
Link: https://lkml.kernel.org/r/20210326151300.195441549@infradead.org
parent 43d5430a

tools/objtool/check.c

+22 −6
Original line number Original line Diff line number Diff line
@@ -797,6 +797,25 @@ __weak bool arch_is_retpoline(struct symbol *sym) 
	return false;

	return false;

}

}





#define NEGATIVE_RELOC	((void *)-1L)



static struct reloc *insn_reloc(struct objtool_file *file, struct instruction *insn)

{

	if (insn->reloc == NEGATIVE_RELOC)

		return NULL;



	if (!insn->reloc) {

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

						       insn->offset, insn->len);

		if (!insn->reloc) {

			insn->reloc = NEGATIVE_RELOC;

			return NULL;

		}

	}



	return insn->reloc;

}



/*

/*

 * Find the destination instructions for all jumps.

 * Find the destination instructions for all jumps.

 */

 */
@@ -811,8 +830,7 @@ static int add_jump_destinations(struct objtool_file *file) 
		if (!is_static_jump(insn))

		if (!is_static_jump(insn))

			continue;

			continue;





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

		reloc = insn_reloc(file, insn);

						 insn->offset, insn->len);

		if (!reloc) {

		if (!reloc) {

			dest_sec = insn->sec;

			dest_sec = insn->sec;

			dest_off = arch_jump_destination(insn);

			dest_off = arch_jump_destination(insn);
@@ -944,8 +962,7 @@ static int add_call_destinations(struct objtool_file *file) 
		if (insn->type != INSN_CALL)

		if (insn->type != INSN_CALL)

			continue;

			continue;





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

		reloc = insn_reloc(file, insn);

					       insn->offset, insn->len);

		if (!reloc) {

		if (!reloc) {

			dest_off = arch_jump_destination(insn);

			dest_off = arch_jump_destination(insn);

			insn->call_dest = find_call_destination(insn->sec, dest_off);

			insn->call_dest = find_call_destination(insn->sec, dest_off);
@@ -1144,8 +1161,7 @@ static int handle_group_alt(struct objtool_file *file, 
		 * alternatives code can adjust the relative offsets

		 * alternatives code can adjust the relative offsets

		 * accordingly.

		 * accordingly.

		 */

		 */

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

		alt_reloc = insn_reloc(file, insn);

						   insn->offset, insn->len);

		if (alt_reloc &&

		if (alt_reloc &&

		    !arch_support_alt_relocation(special_alt, insn, alt_reloc)) {

		    !arch_support_alt_relocation(special_alt, insn, alt_reloc)) {

tools/objtool/include/objtool/check.h

+1 −0
Original line number Original line Diff line number Diff line
@@ -56,6 +56,7 @@ struct instruction { 
	struct instruction *jump_dest;

	struct instruction *jump_dest;

	struct instruction *first_jump_src;

	struct instruction *first_jump_src;

	struct reloc *jump_table;

	struct reloc *jump_table;

	struct reloc *reloc;

	struct list_head alts;

	struct list_head alts;

	struct symbol *func;

	struct symbol *func;

	struct list_head stack_ops;

	struct list_head stack_ops;