linux-stable/tools/objtool/arch.h
Peter Zijlstra c6aecc29d2 objtool/x86: Fix SRSO mess
commit 4ae68b26c3 upstream.

Objtool --rethunk does two things:

 - it collects all (tail) call's of __x86_return_thunk and places them
   into .return_sites. These are typically compiler generated, but
   RET also emits this same.

 - it fudges the validation of the __x86_return_thunk symbol; because
   this symbol is inside another instruction, it can't actually find
   the instruction pointed to by the symbol offset and gets upset.

Because these two things pertained to the same symbol, there was no
pressing need to separate these two separate things.

However, alas, along comes SRSO and more crazy things to deal with
appeared.

The SRSO patch itself added the following symbol names to identify as
rethunk:

  'srso_untrain_ret', 'srso_safe_ret' and '__ret'

Where '__ret' is the old retbleed return thunk, 'srso_safe_ret' is a
new similarly embedded return thunk, and 'srso_untrain_ret' is
completely unrelated to anything the above does (and was only included
because of that INT3 vs UD2 issue fixed previous).

Clear things up by adding a second category for the embedded instruction
thing.

Fixes: fb3bd914b3 ("x86/srso: Add a Speculative RAS Overflow mitigation")
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20230814121148.704502245@infradead.org
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-08-30 16:23:09 +02:00

97 lines
1.8 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 "objtool.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_BUG,
INSN_NOP,
INSN_STAC,
INSN_CLAC,
INSN_STD,
INSN_CLD,
INSN_TRAP,
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;
struct list_head list;
};
struct instruction;
void arch_initial_func_cfi_state(struct cfi_init_state *state);
int arch_decode_instruction(const struct elf *elf, const struct section *sec,
unsigned long offset, unsigned int maxlen,
unsigned int *len, enum insn_type *type,
unsigned long *immediate,
struct list_head *ops_list);
bool arch_callee_saved_reg(unsigned char reg);
unsigned long arch_jump_destination(struct instruction *insn);
unsigned long arch_dest_reloc_offset(int addend);
const char *arch_nop_insn(int len);
const char *arch_ret_insn(int len);
int arch_decode_hint_reg(u8 sp_reg, int *base);
bool arch_is_retpoline(struct symbol *sym);
bool arch_is_rethunk(struct symbol *sym);
bool arch_is_embedded_insn(struct symbol *sym);
int arch_rewrite_retpolines(struct objtool_file *file);
#endif /* _ARCH_H */