Commit bfb08f22 authored by Raphael Gault's avatar Raphael Gault Committed by Ingo Molnar
Browse files

objtool: Add abstraction for destination offsets 



The jump and call destination relocation offsets are x86-specific.
Abstract them by calling arch-specific implementations.

[ jthierry: Remove superfluous comment; replace other addend offsets
      	    with arch_dest_rela_offset() ]

Signed-off-by: default avatarRaphael Gault <raphael.gault@arm.com>
Signed-off-by: default avatarJulien Thierry <jthierry@redhat.com>
Acked-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: default avatarMiroslav Benes <mbenes@suse.cz>
Signed-off-by: default avatarJosh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent aff5e169

tools/objtool/arch.h

+6 −0
Original line number Diff line number Diff line
@@ -66,6 +66,8 @@ struct stack_op { 
	struct op_src src;

};



struct instruction;



void arch_initial_func_cfi_state(struct cfi_state *state);



int arch_decode_instruction(struct elf *elf, struct section *sec,
@@ -75,4 +77,8 @@ int arch_decode_instruction(struct elf *elf, struct section *sec, 


bool arch_callee_saved_reg(unsigned char reg);



unsigned long arch_jump_destination(struct instruction *insn);



unsigned long arch_dest_rela_offset(int addend);



#endif /* _ARCH_H */

tools/objtool/arch/x86/decode.c

+11 −0
Original line number Diff line number Diff line
@@ -11,6 +11,7 @@ 
#include "../../../arch/x86/lib/inat.c"

#include "../../../arch/x86/lib/insn.c"



#include "../../check.h"

#include "../../elf.h"

#include "../../arch.h"

#include "../../warn.h"
@@ -66,6 +67,16 @@ bool arch_callee_saved_reg(unsigned char reg) 
	}

}



unsigned long arch_dest_rela_offset(int addend)

{

	return addend + 4;

}



unsigned long arch_jump_destination(struct instruction *insn)

{

	return insn->offset + insn->len + insn->immediate;

}



int arch_decode_instruction(struct elf *elf, struct section *sec,

			    unsigned long offset, unsigned int maxlen,

			    unsigned int *len, enum insn_type *type,

tools/objtool/check.c

+10 −8
Original line number Diff line number Diff line
@@ -574,13 +574,14 @@ static int add_jump_destinations(struct objtool_file *file) 
					       insn->offset, insn->len);

		if (!rela) {

			dest_sec = insn->sec;

			dest_off = insn->offset + insn->len + insn->immediate;

			dest_off = arch_jump_destination(insn);

		} else if (rela->sym->type == STT_SECTION) {

			dest_sec = rela->sym->sec;

			dest_off = rela->addend + 4;

			dest_off = arch_dest_rela_offset(rela->addend);

		} else if (rela->sym->sec->idx) {

			dest_sec = rela->sym->sec;

			dest_off = rela->sym->sym.st_value + rela->addend + 4;

			dest_off = rela->sym->sym.st_value +

				   arch_dest_rela_offset(rela->addend);

		} else if (strstr(rela->sym->name, "_indirect_thunk_")) {

			/*

			 * Retpoline jumps are really dynamic jumps in
@@ -670,7 +671,7 @@ static int add_call_destinations(struct objtool_file *file) 
		rela = find_rela_by_dest_range(file->elf, insn->sec,

					       insn->offset, insn->len);

		if (!rela) {

			dest_off = insn->offset + insn->len + insn->immediate;

			dest_off = arch_jump_destination(insn);

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

			if (!insn->call_dest)

				insn->call_dest = find_symbol_by_offset(insn->sec, dest_off);
@@ -693,13 +694,14 @@ static int add_call_destinations(struct objtool_file *file) 
			}



		} else if (rela->sym->type == STT_SECTION) {

			dest_off = arch_dest_rela_offset(rela->addend);

			insn->call_dest = find_func_by_offset(rela->sym->sec,

							      rela->addend+4);

							      dest_off);

			if (!insn->call_dest) {

				WARN_FUNC("can't find call dest symbol at %s+0x%x",

				WARN_FUNC("can't find call dest symbol at %s+0x%lx",

					  insn->sec, insn->offset,

					  rela->sym->sec->name,

					  rela->addend + 4);

					  dest_off);

				return -1;

			}

		} else
@@ -810,7 +812,7 @@ static int handle_group_alt(struct objtool_file *file, 
		if (!insn->immediate)

			continue;



		dest_off = insn->offset + insn->len + insn->immediate;

		dest_off = arch_jump_destination(insn);

		if (dest_off == special_alt->new_off + special_alt->new_len) {

			if (!fake_jump) {

				WARN("%s: alternative jump to end of section",

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