mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-11-01 08:58:07 +00:00
6256e668b7
Use int3 instead of debug trap exception for single-stepping the probed instructions. Some instructions which change the ip registers or modify IF flags are emulated because those are not able to be single-stepped by int3 or may allow the interrupt while single-stepping. This actually changes the kprobes behavior. - kprobes can not probe following instructions; int3, iret, far jmp/call which get absolute address as immediate, indirect far jmp/call, indirect near jmp/call with addressing by memory (register-based indirect jmp/call are OK), and vmcall/vmlaunch/vmresume/vmxoff. - If the kprobe post_handler doesn't set before registering, it may not be called in some case even if you set it afterwards. (IOW, kprobe booster is enabled at registration, user can not change it) But both are rare issue, unsupported instructions will not be used in the kernel (or rarely used), and post_handlers are rarely used (I don't see it except for the test code). Suggested-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/161469874601.49483.11985325887166921076.stgit@devnote2
128 lines
3.4 KiB
C
128 lines
3.4 KiB
C
/* SPDX-License-Identifier: GPL-2.0-or-later */
|
|
#ifndef _ASM_X86_KPROBES_H
|
|
#define _ASM_X86_KPROBES_H
|
|
/*
|
|
* Kernel Probes (KProbes)
|
|
*
|
|
* Copyright (C) IBM Corporation, 2002, 2004
|
|
*
|
|
* See arch/x86/kernel/kprobes.c for x86 kprobes history.
|
|
*/
|
|
|
|
#include <asm-generic/kprobes.h>
|
|
|
|
#ifdef CONFIG_KPROBES
|
|
#include <linux/types.h>
|
|
#include <linux/ptrace.h>
|
|
#include <linux/percpu.h>
|
|
#include <asm/text-patching.h>
|
|
#include <asm/insn.h>
|
|
|
|
#define __ARCH_WANT_KPROBES_INSN_SLOT
|
|
|
|
struct pt_regs;
|
|
struct kprobe;
|
|
|
|
typedef u8 kprobe_opcode_t;
|
|
|
|
#define MAX_STACK_SIZE 64
|
|
#define CUR_STACK_SIZE(ADDR) \
|
|
(current_top_of_stack() - (unsigned long)(ADDR))
|
|
#define MIN_STACK_SIZE(ADDR) \
|
|
(MAX_STACK_SIZE < CUR_STACK_SIZE(ADDR) ? \
|
|
MAX_STACK_SIZE : CUR_STACK_SIZE(ADDR))
|
|
|
|
#define flush_insn_slot(p) do { } while (0)
|
|
|
|
/* optinsn template addresses */
|
|
extern __visible kprobe_opcode_t optprobe_template_entry[];
|
|
extern __visible kprobe_opcode_t optprobe_template_clac[];
|
|
extern __visible kprobe_opcode_t optprobe_template_val[];
|
|
extern __visible kprobe_opcode_t optprobe_template_call[];
|
|
extern __visible kprobe_opcode_t optprobe_template_end[];
|
|
#define MAX_OPTIMIZED_LENGTH (MAX_INSN_SIZE + DISP32_SIZE)
|
|
#define MAX_OPTINSN_SIZE \
|
|
(((unsigned long)optprobe_template_end - \
|
|
(unsigned long)optprobe_template_entry) + \
|
|
MAX_OPTIMIZED_LENGTH + JMP32_INSN_SIZE)
|
|
|
|
extern const int kretprobe_blacklist_size;
|
|
|
|
void arch_remove_kprobe(struct kprobe *p);
|
|
asmlinkage void kretprobe_trampoline(void);
|
|
|
|
extern void arch_kprobe_override_function(struct pt_regs *regs);
|
|
|
|
/* Architecture specific copy of original instruction*/
|
|
struct arch_specific_insn {
|
|
/* copy of the original instruction */
|
|
kprobe_opcode_t *insn;
|
|
/*
|
|
* boostable = 0: This instruction type is not boostable.
|
|
* boostable = 1: This instruction has been boosted: we have
|
|
* added a relative jump after the instruction copy in insn,
|
|
* so no single-step and fixup are needed (unless there's
|
|
* a post_handler).
|
|
*/
|
|
unsigned boostable:1;
|
|
unsigned char size; /* The size of insn */
|
|
union {
|
|
unsigned char opcode;
|
|
struct {
|
|
unsigned char type;
|
|
} jcc;
|
|
struct {
|
|
unsigned char type;
|
|
unsigned char asize;
|
|
} loop;
|
|
struct {
|
|
unsigned char reg;
|
|
} indirect;
|
|
};
|
|
s32 rel32; /* relative offset must be s32, s16, or s8 */
|
|
void (*emulate_op)(struct kprobe *p, struct pt_regs *regs);
|
|
/* Number of bytes of text poked */
|
|
int tp_len;
|
|
};
|
|
|
|
struct arch_optimized_insn {
|
|
/* copy of the original instructions */
|
|
kprobe_opcode_t copied_insn[DISP32_SIZE];
|
|
/* detour code buffer */
|
|
kprobe_opcode_t *insn;
|
|
/* the size of instructions copied to detour code buffer */
|
|
size_t size;
|
|
};
|
|
|
|
/* Return true (!0) if optinsn is prepared for optimization. */
|
|
static inline int arch_prepared_optinsn(struct arch_optimized_insn *optinsn)
|
|
{
|
|
return optinsn->size;
|
|
}
|
|
|
|
struct prev_kprobe {
|
|
struct kprobe *kp;
|
|
unsigned long status;
|
|
unsigned long old_flags;
|
|
unsigned long saved_flags;
|
|
};
|
|
|
|
/* per-cpu kprobe control block */
|
|
struct kprobe_ctlblk {
|
|
unsigned long kprobe_status;
|
|
unsigned long kprobe_old_flags;
|
|
unsigned long kprobe_saved_flags;
|
|
struct prev_kprobe prev_kprobe;
|
|
};
|
|
|
|
extern int kprobe_fault_handler(struct pt_regs *regs, int trapnr);
|
|
extern int kprobe_exceptions_notify(struct notifier_block *self,
|
|
unsigned long val, void *data);
|
|
extern int kprobe_int3_handler(struct pt_regs *regs);
|
|
|
|
#else
|
|
|
|
static inline int kprobe_debug_handler(struct pt_regs *regs) { return 0; }
|
|
|
|
#endif /* CONFIG_KPROBES */
|
|
#endif /* _ASM_X86_KPROBES_H */
|