linux/tools/objtool/arch.h
Josh Poimboeuf b68b990706 objtool: Support conditional retpolines
A Clang-built kernel is showing the following warning:

  arch/x86/kernel/platform-quirks.o: warning: objtool: x86_early_init_platform_quirks()+0x84: unreachable instruction

That corresponds to this code:

  7e:   0f 85 00 00 00 00       jne    84 <x86_early_init_platform_quirks+0x84>
                        80: R_X86_64_PC32       __x86_indirect_thunk_r11-0x4
  84:   c3                      retq

This is a conditional retpoline sibling call, which is now possible
thanks to retpolines.  Objtool hasn't seen that before.  It's
incorrectly interpreting the conditional jump as an unconditional
dynamic jump.

Reported-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/30d4c758b267ef487fb97e6ecb2f148ad007b554.1563413318.git.jpoimboe@redhat.com
2019-07-18 21:01:10 +02:00

79 lines
1.3 KiB
C

/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
* Copyright (C) 2015 Josh Poimboeuf <jpoimboe@redhat.com>
*/
#ifndef _ARCH_H
#define _ARCH_H
#include <stdbool.h>
#include <linux/list.h>
#include "elf.h"
#include "cfi.h"
enum insn_type {
INSN_JUMP_CONDITIONAL,
INSN_JUMP_UNCONDITIONAL,
INSN_JUMP_DYNAMIC,
INSN_JUMP_DYNAMIC_CONDITIONAL,
INSN_CALL,
INSN_CALL_DYNAMIC,
INSN_RETURN,
INSN_CONTEXT_SWITCH,
INSN_STACK,
INSN_BUG,
INSN_NOP,
INSN_STAC,
INSN_CLAC,
INSN_STD,
INSN_CLD,
INSN_OTHER,
};
enum op_dest_type {
OP_DEST_REG,
OP_DEST_REG_INDIRECT,
OP_DEST_MEM,
OP_DEST_PUSH,
OP_DEST_PUSHF,
OP_DEST_LEAVE,
};
struct op_dest {
enum op_dest_type type;
unsigned char reg;
int offset;
};
enum op_src_type {
OP_SRC_REG,
OP_SRC_REG_INDIRECT,
OP_SRC_CONST,
OP_SRC_POP,
OP_SRC_POPF,
OP_SRC_ADD,
OP_SRC_AND,
};
struct op_src {
enum op_src_type type;
unsigned char reg;
int offset;
};
struct stack_op {
struct op_dest dest;
struct op_src src;
};
void arch_initial_func_cfi_state(struct cfi_state *state);
int arch_decode_instruction(struct elf *elf, struct section *sec,
unsigned long offset, unsigned int maxlen,
unsigned int *len, enum insn_type *type,
unsigned long *immediate, struct stack_op *op);
bool arch_callee_saved_reg(unsigned char reg);
#endif /* _ARCH_H */