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Date: Fri, 7 Apr 2023 10:15:00 +0800
From: Tiezhu Yang <yangtiezhu@...ngson.cn>
To: Huacai Chen <chenhuacai@...nel.org>,
WANG Xuerui <kernel@...0n.name>
Cc: loongarch@...ts.linux.dev, linux-kernel@...r.kernel.org,
loongson-kernel@...ts.loongnix.cn
Subject: [RFC PATCH 2/3] LoongArch: Add larch_insn_gen_break() to generate break insn
There exist various break insns such as BRK_KPROBE_BP, BRK_KPROBE_SSTEPBP,
BRK_UPROBE_BP and BRK_UPROBE_XOLBP, add larch_insn_gen_break() to generate
break insns simpler and easier.
This is preparation for later patch, no functionality change.
Signed-off-by: Tiezhu Yang <yangtiezhu@...ngson.cn>
---
arch/loongarch/include/asm/inst.h | 30 +++++++++++++++++++++++++++---
arch/loongarch/include/asm/kprobes.h | 2 +-
arch/loongarch/kernel/inst.c | 9 +++++++++
arch/loongarch/kernel/kprobes.c | 17 +++--------------
4 files changed, 40 insertions(+), 18 deletions(-)
diff --git a/arch/loongarch/include/asm/inst.h b/arch/loongarch/include/asm/inst.h
index af494b5..a0fce06 100644
--- a/arch/loongarch/include/asm/inst.h
+++ b/arch/loongarch/include/asm/inst.h
@@ -409,8 +409,12 @@ static inline bool is_self_loop_ins(union loongarch_instruction *ip, struct pt_r
void simu_pc(struct pt_regs *regs, union loongarch_instruction insn);
void simu_branch(struct pt_regs *regs, union loongarch_instruction insn);
-static inline bool insns_not_supported(union loongarch_instruction insn)
+static inline bool insns_not_supported(u32 code)
{
+ union loongarch_instruction insn;
+
+ insn.word = code;
+
switch (insn.reg2i14_format.opcode) {
case llw_op:
case lld_op:
@@ -429,8 +433,12 @@ static inline bool insns_not_supported(union loongarch_instruction insn)
return false;
}
-static inline bool insns_need_simulation(union loongarch_instruction insn)
+static inline bool insns_need_simulation(u32 code)
{
+ union loongarch_instruction insn;
+
+ insn.word = code;
+
if (is_pc_ins(&insn))
return true;
@@ -440,8 +448,12 @@ static inline bool insns_need_simulation(union loongarch_instruction insn)
return false;
}
-static inline void arch_simulate_insn(union loongarch_instruction insn, struct pt_regs *regs)
+static inline void arch_simulate_insn(u32 code, struct pt_regs *regs)
{
+ union loongarch_instruction insn;
+
+ insn.word = code;
+
if (is_pc_ins(&insn))
simu_pc(regs, insn);
else if (is_branch_ins(&insn))
@@ -456,6 +468,8 @@ u32 larch_insn_gen_nop(void);
u32 larch_insn_gen_b(unsigned long pc, unsigned long dest);
u32 larch_insn_gen_bl(unsigned long pc, unsigned long dest);
+u32 larch_insn_gen_break(int imm);
+
u32 larch_insn_gen_or(enum loongarch_gpr rd, enum loongarch_gpr rj, enum loongarch_gpr rk);
u32 larch_insn_gen_move(enum loongarch_gpr rd, enum loongarch_gpr rj);
@@ -474,6 +488,16 @@ static inline bool unsigned_imm_check(unsigned long val, unsigned int bit)
return val < (1UL << bit);
}
+#define DEF_EMIT_REG0I15_FORMAT(NAME, OP) \
+static inline void emit_##NAME(union loongarch_instruction *insn, \
+ int imm) \
+{ \
+ insn->reg0i15_format.opcode = OP; \
+ insn->reg0i15_format.immediate = imm; \
+}
+
+DEF_EMIT_REG0I15_FORMAT(break, break_op)
+
#define DEF_EMIT_REG0I26_FORMAT(NAME, OP) \
static inline void emit_##NAME(union loongarch_instruction *insn, \
int offset) \
diff --git a/arch/loongarch/include/asm/kprobes.h b/arch/loongarch/include/asm/kprobes.h
index 798020a..7ef7a0f 100644
--- a/arch/loongarch/include/asm/kprobes.h
+++ b/arch/loongarch/include/asm/kprobes.h
@@ -22,7 +22,7 @@ do { \
#define kretprobe_blacklist_size 0
-typedef union loongarch_instruction kprobe_opcode_t;
+typedef u32 kprobe_opcode_t;
/* Architecture specific copy of original instruction */
struct arch_specific_insn {
diff --git a/arch/loongarch/kernel/inst.c b/arch/loongarch/kernel/inst.c
index 258ef26..31b8efe 100644
--- a/arch/loongarch/kernel/inst.c
+++ b/arch/loongarch/kernel/inst.c
@@ -208,6 +208,15 @@ u32 larch_insn_gen_bl(unsigned long pc, unsigned long dest)
return insn.word;
}
+u32 larch_insn_gen_break(int imm)
+{
+ union loongarch_instruction insn;
+
+ emit_break(&insn, imm);
+
+ return insn.word;
+}
+
u32 larch_insn_gen_or(enum loongarch_gpr rd, enum loongarch_gpr rj, enum loongarch_gpr rk)
{
union loongarch_instruction insn;
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)
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
--
2.1.0
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