Commit c536ed2f authored by Peter Zijlstra's avatar Peter Zijlstra Committed by Ingo Molnar
Browse files

objtool: Remove SAVE/RESTORE hints 



The SAVE/RESTORE hints are now unused; remove them.

Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: default avatarMiroslav Benes <mbenes@suse.cz>
Reviewed-by: default avatarAlexandre Chartre <alexandre.chartre@oracle.com>
Acked-by: default avatarJosh Poimboeuf <jpoimboe@redhat.com>
Link: https://lkml.kernel.org/r/20200416115118.926738768@infradead.org


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 9f2dfd61

arch/x86/include/asm/orc_types.h

+1 −3
Original line number Diff line number Diff line
@@ -58,9 +58,7 @@ 
#define ORC_TYPE_CALL			0

#define ORC_TYPE_REGS			1

#define ORC_TYPE_REGS_IRET		2

#define UNWIND_HINT_TYPE_SAVE		3

#define UNWIND_HINT_TYPE_RESTORE	4

#define UNWIND_HINT_TYPE_RET_OFFSET	5

#define UNWIND_HINT_TYPE_RET_OFFSET	3



#ifndef __ASSEMBLY__

/*

arch/x86/include/asm/unwind_hints.h

+0 −27
Original line number Diff line number Diff line
@@ -86,15 +86,6 @@ 
	UNWIND_HINT sp_offset=\sp_offset

.endm



.macro UNWIND_HINT_SAVE

	UNWIND_HINT type=UNWIND_HINT_TYPE_SAVE

.endm



.macro UNWIND_HINT_RESTORE

	UNWIND_HINT type=UNWIND_HINT_TYPE_RESTORE

.endm





/*

 * RET_OFFSET: Used on instructions that terminate a function; mostly RETURN

 * and sibling calls. On these, sp_offset denotes the expected offset from
@@ -104,24 +95,6 @@ 
	UNWIND_HINT type=UNWIND_HINT_TYPE_RET_OFFSET sp_offset=\sp_offset

.endm



#else /* !__ASSEMBLY__ */



#define UNWIND_HINT(sp_reg, sp_offset, type, end)		\

	"987: \n\t"						\

	".pushsection .discard.unwind_hints\n\t"		\

	/* struct unwind_hint */				\

	".long 987b - .\n\t"					\

	".short " __stringify(sp_offset) "\n\t"			\

	".byte " __stringify(sp_reg) "\n\t"			\

	".byte " __stringify(type) "\n\t"			\

	".byte " __stringify(end) "\n\t"			\

	".balign 4 \n\t"					\

	".popsection\n\t"



#define UNWIND_HINT_SAVE UNWIND_HINT(0, 0, UNWIND_HINT_TYPE_SAVE, 0)



#define UNWIND_HINT_RESTORE UNWIND_HINT(0, 0, UNWIND_HINT_TYPE_RESTORE, 0)



#endif /* __ASSEMBLY__ */



#endif /* _ASM_X86_UNWIND_HINTS_H */

tools/arch/x86/include/asm/orc_types.h

+1 −3
Original line number Diff line number Diff line
@@ -58,9 +58,7 @@ 
#define ORC_TYPE_CALL			0

#define ORC_TYPE_REGS			1

#define ORC_TYPE_REGS_IRET		2

#define UNWIND_HINT_TYPE_SAVE		3

#define UNWIND_HINT_TYPE_RESTORE	4

#define UNWIND_HINT_TYPE_RET_OFFSET	5

#define UNWIND_HINT_TYPE_RET_OFFSET	3



#ifndef __ASSEMBLY__

/*

tools/objtool/check.c

+3 −39
Original line number Diff line number Diff line
@@ -1254,15 +1254,7 @@ static int read_unwind_hints(struct objtool_file *file) 


		cfa = &insn->state.cfa;



		if (hint->type == UNWIND_HINT_TYPE_SAVE) {

			insn->save = true;

			continue;



		} else if (hint->type == UNWIND_HINT_TYPE_RESTORE) {

			insn->restore = true;

			insn->hint = true;



		} else if (hint->type == UNWIND_HINT_TYPE_RET_OFFSET) {

		if (hint->type == UNWIND_HINT_TYPE_RET_OFFSET) {

			insn->ret_offset = hint->sp_offset;

			continue;

		}
@@ -2113,37 +2105,9 @@ static int validate_branch(struct objtool_file *file, struct symbol *func, 
				return 0;

		}



		if (insn->hint) {

			if (insn->restore) {

				struct instruction *save_insn, *i;



				i = insn;

				save_insn = NULL;

				sym_for_each_insn_continue_reverse(file, func, i) {

					if (i->save) {

						save_insn = i;

						break;

					}

				}



				if (!save_insn) {

					WARN_FUNC("no corresponding CFI save for CFI restore",

						  sec, insn->offset);

					return 1;

				}



				if (!save_insn->visited) {

					WARN_FUNC("objtool isn't smart enough to handle this CFI save/restore combo",

						  sec, insn->offset);

					return 1;

				}



				insn->state = save_insn->state;

			}



		if (insn->hint)

			state = insn->state;



		} else

		else

			insn->state = state;



		insn->visited |= visited;

tools/objtool/check.h

+1 −1
Original line number Diff line number Diff line
@@ -34,7 +34,7 @@ struct instruction { 
	enum insn_type type;

	unsigned long immediate;

	bool alt_group, dead_end, ignore, ignore_alts;

	bool hint, save, restore;

	bool hint;

	bool retpoline_safe;

	u8 visited;

	u8 ret_offset;