c22b0bcb1d
This patch enables "kprobe & kretprobe" to work with ftrace interface. It utilized software breakpoint as single-step mechanism. Some instructions which can't be single-step executed must be simulated in kernel execution slot, such as: branch, jal, auipc, la ... Some instructions should be rejected for probing and we use a blacklist to filter, such as: ecall, ebreak, ... We use ebreak & c.ebreak to replace origin instruction and the kprobe handler prepares an executable memory slot for out-of-line execution with a copy of the original instruction being probed. In execution slot we add ebreak behind original instruction to simulate a single-setp mechanism. The patch is based on packi's work [1] and csky's work [2]. - The kprobes_trampoline.S is all from packi's patch - The single-step mechanism is new designed for riscv without hw single-step trap - The simulation codes are from csky - Frankly, all codes refer to other archs' implementation [1] https://lore.kernel.org/linux-riscv/20181113195804.22825-1-me@packi.ch/ [2] https://lore.kernel.org/linux-csky/20200403044150.20562-9-guoren@kernel.org/ Signed-off-by: Guo Ren <guoren@linux.alibaba.com> Co-developed-by: Patrick Stählin <me@packi.ch> Signed-off-by: Patrick Stählin <me@packi.ch> Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Tested-by: Zong Li <zong.li@sifive.com> Reviewed-by: Pekka Enberg <penberg@kernel.org> Cc: Patrick Stählin <me@packi.ch> Cc: Palmer Dabbelt <palmerdabbelt@google.com> Cc: Björn Töpel <bjorn.topel@gmail.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
55 lines
1.3 KiB
C
55 lines
1.3 KiB
C
/* SPDX-License-Identifier: GPL-2.0-only */
|
|
/*
|
|
* Copied from arch/arm64/include/asm/kprobes.h
|
|
*
|
|
* Copyright (C) 2013 Linaro Limited
|
|
* Copyright (C) 2017 SiFive
|
|
*/
|
|
|
|
#ifndef _ASM_RISCV_KPROBES_H
|
|
#define _ASM_RISCV_KPROBES_H
|
|
|
|
#include <asm-generic/kprobes.h>
|
|
|
|
#ifdef CONFIG_KPROBES
|
|
#include <linux/types.h>
|
|
#include <linux/ptrace.h>
|
|
#include <linux/percpu.h>
|
|
|
|
#define __ARCH_WANT_KPROBES_INSN_SLOT
|
|
#define MAX_INSN_SIZE 2
|
|
|
|
#define flush_insn_slot(p) do { } while (0)
|
|
#define kretprobe_blacklist_size 0
|
|
|
|
#include <asm/probes.h>
|
|
|
|
struct prev_kprobe {
|
|
struct kprobe *kp;
|
|
unsigned int status;
|
|
};
|
|
|
|
/* Single step context for kprobe */
|
|
struct kprobe_step_ctx {
|
|
unsigned long ss_pending;
|
|
unsigned long match_addr;
|
|
};
|
|
|
|
/* per-cpu kprobe control block */
|
|
struct kprobe_ctlblk {
|
|
unsigned int kprobe_status;
|
|
unsigned long saved_status;
|
|
struct prev_kprobe prev_kprobe;
|
|
struct kprobe_step_ctx ss_ctx;
|
|
};
|
|
|
|
void arch_remove_kprobe(struct kprobe *p);
|
|
int kprobe_fault_handler(struct pt_regs *regs, unsigned int trapnr);
|
|
bool kprobe_breakpoint_handler(struct pt_regs *regs);
|
|
bool kprobe_single_step_handler(struct pt_regs *regs);
|
|
void kretprobe_trampoline(void);
|
|
void __kprobes *trampoline_probe_handler(struct pt_regs *regs);
|
|
|
|
#endif /* CONFIG_KPROBES */
|
|
#endif /* _ASM_RISCV_KPROBES_H */
|