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linux-next/arch/x86/include/asm/kprobes.h
Adrian Hunter 3e46bb40af perf/x86: Add perf text poke events for kprobes
Add perf text poke events for kprobes. That includes:

 - the replaced instruction(s) which are executed out-of-line
   i.e. arch_copy_kprobe() and arch_remove_kprobe()

 - the INT3 that activates the kprobe
   i.e. arch_arm_kprobe() and arch_disarm_kprobe()

 - optimised kprobe function
   i.e. arch_prepare_optimized_kprobe() and
      __arch_remove_optimized_kprobe()

 - optimised kprobe
   i.e. arch_optimize_kprobes() and arch_unoptimize_kprobe()

Resulting in 8 possible text_poke events:

 0:  NULL -> probe.ainsn.insn (if ainsn.boostable && !kp.post_handler)
					arch_copy_kprobe()

 1:  old0 -> INT3			arch_arm_kprobe()

 // boosted kprobe active

 2:  NULL -> optprobe_trampoline	arch_prepare_optimized_kprobe()

 3:  INT3,old1,old2,old3,old4 -> JMP32	arch_optimize_kprobes()

 // optprobe active

 4:  JMP32 -> INT3,old1,old2,old3,old4

 // optprobe disabled and kprobe active (this sometimes goes back to 3)
					arch_unoptimize_kprobe()

 5:  optprobe_trampoline -> NULL	arch_remove_optimized_kprobe()

 // boosted kprobe active

 6:  INT3 -> old0			arch_disarm_kprobe()

 7:  probe.ainsn.insn -> NULL (if ainsn.boostable && !kp.post_handler)
					arch_remove_kprobe()

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Link: https://lkml.kernel.org/r/20200512121922.8997-6-adrian.hunter@intel.com
2020-06-15 14:09:49 +02:00

111 lines
3.1 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 = false: This instruction type is not boostable.
* boostable = true: 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).
*/
bool boostable;
bool if_modifier;
/* 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);
extern int kprobe_debug_handler(struct pt_regs *regs);
#endif /* CONFIG_KPROBES */
#endif /* _ASM_X86_KPROBES_H */