Commit 317f2a64 authored by Peter Zijlstra's avatar Peter Zijlstra
Browse files

objtool: Convert instrumentation_{begin,end}() 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/20241128094311.245980207@infradead.org
parent bf5febeb

include/linux/instrumentation.h

+5 −6
Original line number Diff line number Diff line
@@ -4,14 +4,14 @@ 


#ifdef CONFIG_NOINSTR_VALIDATION



#include <linux/objtool.h>

#include <linux/stringify.h>



/* Begin/end of an instrumentation safe region */

#define __instrumentation_begin(c) ({					\

	asm volatile(__stringify(c) ": nop\n\t"				\

		     ".pushsection .discard.instr_begin\n\t"		\

		     ".long " __stringify(c) "b - .\n\t"		\

		     ".popsection\n\t" : : "i" (c));			\

		     __ASM_ANNOTATE(__ASM_BREF(c), ANNOTYPE_INSTR_BEGIN)\

		     : : "i" (c));					\

})

#define instrumentation_begin() __instrumentation_begin(__COUNTER__)
@@ -48,9 +48,8 @@ 
 */

#define __instrumentation_end(c) ({					\

	asm volatile(__stringify(c) ": nop\n\t"				\

		     ".pushsection .discard.instr_end\n\t"		\

		     ".long " __stringify(c) "b - .\n\t"		\

		     ".popsection\n\t" : : "i" (c));			\

		     __ASM_ANNOTATE(__ASM_BREF(c), ANNOTYPE_INSTR_END)	\

		     : : "i" (c));					\

})

#define instrumentation_end() __instrumentation_end(__COUNTER__)

#else /* !CONFIG_NOINSTR_VALIDATION */

include/linux/objtool.h

+9 −3
Original line number Diff line number Diff line
@@ -51,13 +51,18 @@ 
	".long 998b\n\t"						\

	".popsection\n\t"



#define ASM_ANNOTATE(type)						\

	"911:\n\t"							\

#define __ASM_BREF(label)	label ## b



#define __ASM_ANNOTATE(label, type)					\

	".pushsection .discard.annotate_insn,\"M\",@progbits,8\n\t"	\

	".long 911b - .\n\t"						\

	".long " __stringify(label) " - .\n\t"			\

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

	".popsection\n\t"



#define ASM_ANNOTATE(type)						\

	"911:\n\t"						\

	__ASM_ANNOTATE(911b, type)



#define ANNOTATE_NOENDBR	ASM_ANNOTATE(ANNOTYPE_NOENDBR)



#else /* __ASSEMBLY__ */
@@ -161,6 +166,7 @@ 
#define UNWIND_HINT(type, sp_reg, sp_offset, signal) "\n\t"

#define STACK_FRAME_NON_STANDARD(func)

#define STACK_FRAME_NON_STANDARD_FP(func)

#define __ASM_ANNOTATE(label, type)

#define ASM_ANNOTATE(type)

#define ANNOTATE_NOENDBR

#define ASM_REACHABLE

include/linux/objtool_types.h

+2 −0
Original line number Diff line number Diff line
@@ -59,5 +59,7 @@ struct unwind_hint { 
 */

#define ANNOTYPE_NOENDBR		1

#define ANNOTYPE_RETPOLINE_SAFE		2

#define ANNOTYPE_INSTR_BEGIN		3

#define ANNOTYPE_INSTR_END		4



#endif /* _LINUX_OBJTOOL_TYPES_H */

tools/include/linux/objtool_types.h

+2 −0
Original line number Diff line number Diff line
@@ -59,5 +59,7 @@ struct unwind_hint { 
 */

#define ANNOTYPE_NOENDBR		1

#define ANNOTYPE_RETPOLINE_SAFE		2

#define ANNOTYPE_INSTR_BEGIN		3

#define ANNOTYPE_INSTR_END		4



#endif /* _LINUX_OBJTOOL_TYPES_H */

tools/objtool/check.c

+10 −39
Original line number Diff line number Diff line
@@ -2440,48 +2440,19 @@ static int __annotate_retpoline_safe(int type, struct instruction *insn) 
	return 0;

}



static int read_instr_hints(struct objtool_file *file)

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

{

	struct section *rsec;

	struct instruction *insn;

	struct reloc *reloc;



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

	if (!rsec)

		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.instr_end entry");

			return -1;

		}

	switch (type) {

	case ANNOTYPE_INSTR_BEGIN:

		insn->instr++;

		break;



	case ANNOTYPE_INSTR_END:

		insn->instr--;

	}



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

	if (!rsec)

		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.instr_begin entry");

			return -1;

		}

		break;



		insn->instr++;

	default:

		break;

	}



	return 0;
@@ -2730,7 +2701,7 @@ static int decode_sections(struct objtool_file *file) 
	if (ret)

		return ret;



	ret = read_instr_hints(file);

	ret = read_annotate(file, __annotate_instr);

	if (ret)

		return ret;