Commit bf5febeb authored by Peter Zijlstra's avatar Peter Zijlstra
Browse files

objtool: Convert ANNOTATE_RETPOLINE_SAFE to ANNOTATE 



Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: default avatarJosh Poimboeuf <jpoimboe@kernel.org>
Link: https://lore.kernel.org/r/20241128094311.145275669@infradead.org
parent 22c3d580

arch/x86/include/asm/nospec-branch.h

+2 −11
Original line number Diff line number Diff line
@@ -184,12 +184,7 @@ 
 * objtool the subsequent indirect jump/call is vouched safe for retpoline

 * builds.

 */

.macro ANNOTATE_RETPOLINE_SAFE

.Lhere_\@:

	.pushsection .discard.retpoline_safe

	.long .Lhere_\@

	.popsection

.endm

#define ANNOTATE_RETPOLINE_SAFE	ANNOTATE type=ANNOTYPE_RETPOLINE_SAFE



/*

 * (ab)use RETPOLINE_SAFE on RET to annotate away 'bare' RET instructions
@@ -350,11 +345,7 @@ 


#else /* __ASSEMBLY__ */



#define ANNOTATE_RETPOLINE_SAFE					\

	"999:\n\t"						\

	".pushsection .discard.retpoline_safe\n\t"		\

	".long 999b\n\t"					\

	".popsection\n\t"

#define ANNOTATE_RETPOLINE_SAFE ASM_ANNOTATE(ANNOTYPE_RETPOLINE_SAFE)



typedef u8 retpoline_thunk_t[RETPOLINE_THUNK_SIZE];

extern retpoline_thunk_t __x86_indirect_thunk_array[];

include/linux/objtool_types.h

+1 −0
Original line number Diff line number Diff line
@@ -58,5 +58,6 @@ struct unwind_hint { 
 * Annotate types

 */

#define ANNOTYPE_NOENDBR		1

#define ANNOTYPE_RETPOLINE_SAFE		2



#endif /* _LINUX_OBJTOOL_TYPES_H */

tools/include/linux/objtool_types.h

+1 −0
Original line number Diff line number Diff line
@@ -58,5 +58,6 @@ struct unwind_hint { 
 * Annotate types

 */

#define ANNOTYPE_NOENDBR		1

#define ANNOTYPE_RETPOLINE_SAFE		2



#endif /* _LINUX_OBJTOOL_TYPES_H */

tools/objtool/check.c

+18 −34
Original line number Diff line number Diff line
@@ -2373,12 +2373,12 @@ static int read_unwind_hints(struct objtool_file *file) 
	return 0;

}



static int read_annotate(struct objtool_file *file, void (*func)(int type, struct instruction *insn))

static int read_annotate(struct objtool_file *file, int (*func)(int type, struct instruction *insn))

{

	struct section *sec;

	struct instruction *insn;

	struct reloc *reloc;

	int type;

	int type, ret;



	sec = find_section_by_name(file->elf, ".discard.annotate_insn");

	if (!sec)
@@ -2406,42 +2406,28 @@ static int read_annotate(struct objtool_file *file, void (*func)(int type, struc 
			return -1;

		}



		func(type, insn);

		ret = func(type, insn);

		if (ret < 0)

			return ret;

	}



	return 0;

}



static void __annotate_noendbr(int type, struct instruction *insn)

static int __annotate_noendbr(int type, struct instruction *insn)

{

	if (type != ANNOTYPE_NOENDBR)

		return;

		return 0;



	insn->noendbr = 1;

	return 0;

}



static int read_retpoline_hints(struct objtool_file *file)

static int __annotate_retpoline_safe(int type, struct instruction *insn)

{

	struct section *rsec;

	struct instruction *insn;

	struct reloc *reloc;



	rsec = find_section_by_name(file->elf, ".rela.discard.retpoline_safe");

	if (!rsec)

	if (type != ANNOTYPE_RETPOLINE_SAFE)

		return 0;



	for_each_reloc(rsec, reloc) {

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

			WARN("unexpected relocation symbol type in %s", rsec->name);

			return -1;

		}



		insn = find_insn(file, reloc->sym->sec, reloc_addend(reloc));

		if (!insn) {

			WARN("bad .discard.retpoline_safe entry");

			return -1;

		}



	if (insn->type != INSN_JUMP_DYNAMIC &&

	    insn->type != INSN_CALL_DYNAMIC &&

	    insn->type != INSN_RETURN &&
@@ -2451,8 +2437,6 @@ static int read_retpoline_hints(struct objtool_file *file) 
	}



	insn->retpoline_safe = true;

	}



	return 0;

}
@@ -2742,7 +2726,7 @@ static int decode_sections(struct objtool_file *file) 
	if (ret)

		return ret;



	ret = read_retpoline_hints(file);

	ret = read_annotate(file, __annotate_retpoline_safe);

	if (ret)

		return ret;