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linux/arch/csky/kernel/probes/decode-insn.c
Guo Ren 33e53ae1ce csky: Add kprobes supported
This patch enable kprobes, kretprobes, ftrace interface. It utilized
software breakpoint and single step debug exceptions, instructions
simulation on csky.

We use USR_BKPT replace origin instruction, and the kprobe handler
prepares an excutable memory slot for out-of-line execution with a
copy of the original instruction being probed. Most of instructions
could be executed by single-step, but some instructions need origin
pc value to execute and we need software simulate these instructions.

Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-04-03 11:14:17 +08:00

50 lines
1.5 KiB
C

// SPDX-License-Identifier: GPL-2.0+
#include <linux/kernel.h>
#include <linux/kprobes.h>
#include <linux/module.h>
#include <linux/kallsyms.h>
#include <asm/sections.h>
#include "decode-insn.h"
#include "simulate-insn.h"
/* Return:
* INSN_REJECTED If instruction is one not allowed to kprobe,
* INSN_GOOD_NO_SLOT If instruction is supported but doesn't use its slot.
*/
enum probe_insn __kprobes
csky_probe_decode_insn(probe_opcode_t *addr, struct arch_probe_insn *api)
{
probe_opcode_t insn = le32_to_cpu(*addr);
CSKY_INSN_SET_SIMULATE(br16, insn);
CSKY_INSN_SET_SIMULATE(bt16, insn);
CSKY_INSN_SET_SIMULATE(bf16, insn);
CSKY_INSN_SET_SIMULATE(jmp16, insn);
CSKY_INSN_SET_SIMULATE(jsr16, insn);
CSKY_INSN_SET_SIMULATE(lrw16, insn);
CSKY_INSN_SET_SIMULATE(pop16, insn);
CSKY_INSN_SET_SIMULATE(br32, insn);
CSKY_INSN_SET_SIMULATE(bt32, insn);
CSKY_INSN_SET_SIMULATE(bf32, insn);
CSKY_INSN_SET_SIMULATE(jmp32, insn);
CSKY_INSN_SET_SIMULATE(jsr32, insn);
CSKY_INSN_SET_SIMULATE(lrw32, insn);
CSKY_INSN_SET_SIMULATE(pop32, insn);
CSKY_INSN_SET_SIMULATE(bez32, insn);
CSKY_INSN_SET_SIMULATE(bnez32, insn);
CSKY_INSN_SET_SIMULATE(bnezad32, insn);
CSKY_INSN_SET_SIMULATE(bhsz32, insn);
CSKY_INSN_SET_SIMULATE(bhz32, insn);
CSKY_INSN_SET_SIMULATE(blsz32, insn);
CSKY_INSN_SET_SIMULATE(blz32, insn);
CSKY_INSN_SET_SIMULATE(bsr32, insn);
CSKY_INSN_SET_SIMULATE(jmpi32, insn);
CSKY_INSN_SET_SIMULATE(jsri32, insn);
return INSN_GOOD;
}