Re: [RFC PATCH 2/3] LoongArch: Add larch_insn_gen_break() to generate break insn

From: Youling Tang
Date: Thu Apr 06 2023 - 22:30:40 EST


/* snip */

diff --git a/arch/loongarch/kernel/kprobes.c b/arch/loongarch/kernel/kprobes.c
index 08c78d2..a5c3712 100644
--- a/arch/loongarch/kernel/kprobes.c
+++ b/arch/loongarch/kernel/kprobes.c
@@ -4,19 +4,8 @@
#include <linux/preempt.h>
#include <asm/break.h>

-static const union loongarch_instruction breakpoint_insn = {
- .reg0i15_format = {
- .opcode = break_op,
- .immediate = BRK_KPROBE_BP,
- }
-};
-
-static const union loongarch_instruction singlestep_insn = {
- .reg0i15_format = {
- .opcode = break_op,
- .immediate = BRK_KPROBE_SSTEPBP,
- }
-};
+#define breakpoint_insn larch_insn_gen_break(BRK_KPROBE_BP)
+#define singlestep_insn larch_insn_gen_break(BRK_KPROBE_SSTEPBP)

IMO, Defined as KPROBE_BP_INSN, KPROBE_SSTEPBP_INSN may be better.

Youling.

DEFINE_PER_CPU(struct kprobe *, current_kprobe);
DEFINE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk);
@@ -253,7 +242,7 @@ bool kprobe_breakpoint_handler(struct pt_regs *regs)
}
}

- if (addr->word != breakpoint_insn.word) {
+ if (*addr != breakpoint_insn) {
/*
* The breakpoint instruction was removed right
* after we hit it. Another cpu has removed