Commit 59953303 authored by Alexandre Chartre's avatar Alexandre Chartre Committed by Peter Zijlstra
Browse files

objtool: Disassemble code with libopcodes instead of running objdump 



objtool executes the objdump command to disassemble code. Use libopcodes
instead to have more control about the disassembly scope and output.
If libopcodes is not present then objtool is built without disassembly
support.

Signed-off-by: default avatarAlexandre Chartre <alexandre.chartre@oracle.com>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: default avatarJosh Poimboeuf <jpoimboe@kernel.org>
Link: https://patch.msgid.link/20251121095340.464045-4-alexandre.chartre@oracle.com
parent 1013f2e3

tools/objtool/.gitignore

+2 −0
Original line number Diff line number Diff line 
# SPDX-License-Identifier: GPL-2.0-only

arch/x86/lib/inat-tables.c

/objtool

feature

FEATURE-DUMP.objtool

fixdep

libsubcmd/

tools/objtool/Build

+2 −1
Original line number Diff line number Diff line
@@ -7,7 +7,8 @@ objtool-y += special.o 
objtool-y += builtin-check.o

objtool-y += elf.o

objtool-y += objtool.o

objtool-y += disas.o



objtool-$(BUILD_DISAS) += disas.o



objtool-$(BUILD_ORC) += orc_gen.o orc_dump.o

objtool-$(BUILD_KLP) += builtin-klp.o klp-diff.o klp-post-link.o

tools/objtool/Makefile

+25 −0
Original line number Diff line number Diff line
@@ -70,6 +70,29 @@ OBJTOOL_CFLAGS += $(if $(elfshdr),,-DLIBELF_USE_DEPRECATED) 
# Always want host compilation.

HOST_OVERRIDES := CC="$(HOSTCC)" LD="$(HOSTLD)" AR="$(HOSTAR)"



#

# To support disassembly, objtool needs libopcodes which is provided

# with libbdf (binutils-dev or binutils-devel package).

#

FEATURE_USER = .objtool

FEATURE_TESTS = libbfd disassembler-init-styled

FEATURE_DISPLAY =

include $(srctree)/tools/build/Makefile.feature



ifeq ($(feature-disassembler-init-styled), 1)

	OBJTOOL_CFLAGS += -DDISASM_INIT_STYLED

endif



BUILD_DISAS := n



ifeq ($(feature-libbfd),1)

	BUILD_DISAS := y

	OBJTOOL_CFLAGS += -DDISAS

	OBJTOOL_LDFLAGS += -lopcodes

endif



export BUILD_DISAS



AWK = awk

MKDIR = mkdir
@@ -103,6 +126,8 @@ clean: $(LIBSUBCMD)-clean 
	$(call QUIET_CLEAN, objtool) $(RM) $(OBJTOOL)

	$(Q)find $(OUTPUT) -name '*.o' -delete -o -name '\.*.cmd' -delete -o -name '\.*.d' -delete

	$(Q)$(RM) $(OUTPUT)arch/x86/lib/inat-tables.c $(OUTPUT)fixdep

	$(Q)$(RM) -- $(OUTPUT)FEATURE-DUMP.objtool

	$(Q)$(RM) -r -- $(OUTPUT)feature



FORCE:

tools/objtool/arch/loongarch/decode.c

+12 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0-or-later

#include <string.h>

#include <objtool/check.h>

#include <objtool/disas.h>

#include <objtool/warn.h>

#include <asm/inst.h>

#include <asm/orc_types.h>
@@ -414,3 +415,14 @@ unsigned long arch_jump_table_sym_offset(struct reloc *reloc, struct reloc *tabl 
		return reloc->sym->offset + reloc_addend(reloc);

	}

}



#ifdef DISAS



int arch_disas_info_init(struct disassemble_info *dinfo)

{

	return disas_info_init(dinfo, bfd_arch_loongarch,

			       bfd_mach_loongarch32, bfd_mach_loongarch64,

			       NULL);

}



#endif /* DISAS */

tools/objtool/arch/powerpc/decode.c

+12 −0
Original line number Diff line number Diff line
@@ -3,6 +3,7 @@ 
#include <stdio.h>

#include <stdlib.h>

#include <objtool/check.h>

#include <objtool/disas.h>

#include <objtool/elf.h>

#include <objtool/arch.h>

#include <objtool/warn.h>
@@ -127,3 +128,14 @@ unsigned int arch_reloc_size(struct reloc *reloc) 
		return 8;

	}

}



#ifdef DISAS



int arch_disas_info_init(struct disassemble_info *dinfo)

{

	return disas_info_init(dinfo, bfd_arch_powerpc,

			       bfd_mach_ppc, bfd_mach_ppc64,

			       NULL);

}



#endif /* DISAS */