diff options
| -rw-r--r-- | arch/arm64/include/asm/insn.h | 5 | ||||
| -rw-r--r-- | arch/arm64/kernel/probes/decode-insn.c | 9 | ||||
| -rw-r--r-- | arch/arm64/kernel/probes/simulate-insn.c | 6 | ||||
| -rw-r--r-- | arch/arm64/kernel/probes/simulate-insn.h | 1 |
4 files changed, 21 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/insn.h b/arch/arm64/include/asm/insn.h index 8c0a36f72d6f..89bc18989b90 100644 --- a/arch/arm64/include/asm/insn.h +++ b/arch/arm64/include/asm/insn.h @@ -575,6 +575,11 @@ static __always_inline u32 aarch64_insn_gen_nop(void) return aarch64_insn_gen_hint(AARCH64_INSN_HINT_NOP); } +static __always_inline bool aarch64_insn_is_nop(u32 insn) +{ + return insn == aarch64_insn_gen_nop(); +} + u32 aarch64_insn_gen_branch_reg(enum aarch64_insn_register reg, enum aarch64_insn_branch_type type); u32 aarch64_insn_gen_load_store_reg(enum aarch64_insn_register reg, diff --git a/arch/arm64/kernel/probes/decode-insn.c b/arch/arm64/kernel/probes/decode-insn.c index 41b100bcb041..e05249f57075 100644 --- a/arch/arm64/kernel/probes/decode-insn.c +++ b/arch/arm64/kernel/probes/decode-insn.c @@ -76,6 +76,15 @@ enum probe_insn __kprobes arm_probe_decode_insn(u32 insn, struct arch_probe_insn *api) { /* + * While 'nop' instruction can execute in the out-of-line slot, + * simulating them in breakpoint handling offers better performance. + */ + if (aarch64_insn_is_nop(insn)) { + api->handler = simulate_nop; + return INSN_GOOD_NO_SLOT; + } + + /* * Instructions reading or modifying the PC won't work from the XOL * slot. */ diff --git a/arch/arm64/kernel/probes/simulate-insn.c b/arch/arm64/kernel/probes/simulate-insn.c index b65334ab79d2..4c6d2d712fbd 100644 --- a/arch/arm64/kernel/probes/simulate-insn.c +++ b/arch/arm64/kernel/probes/simulate-insn.c @@ -196,3 +196,9 @@ simulate_ldrsw_literal(u32 opcode, long addr, struct pt_regs *regs) instruction_pointer_set(regs, instruction_pointer(regs) + 4); } + +void __kprobes +simulate_nop(u32 opcode, long addr, struct pt_regs *regs) +{ + arm64_skip_faulting_instruction(regs, AARCH64_INSN_SIZE); +} diff --git a/arch/arm64/kernel/probes/simulate-insn.h b/arch/arm64/kernel/probes/simulate-insn.h index e065dc92218e..efb2803ec943 100644 --- a/arch/arm64/kernel/probes/simulate-insn.h +++ b/arch/arm64/kernel/probes/simulate-insn.h @@ -16,5 +16,6 @@ void simulate_cbz_cbnz(u32 opcode, long addr, struct pt_regs *regs); void simulate_tbz_tbnz(u32 opcode, long addr, struct pt_regs *regs); void simulate_ldr_literal(u32 opcode, long addr, struct pt_regs *regs); void simulate_ldrsw_literal(u32 opcode, long addr, struct pt_regs *regs); +void simulate_nop(u32 opcode, long addr, struct pt_regs *regs); #endif /* _ARM_KERNEL_KPROBES_SIMULATE_INSN_H */ |