diff options
Diffstat (limited to 'arch/arm64/kernel/probes/decode-insn.c')
| -rw-r--r-- | arch/arm64/kernel/probes/decode-insn.c | 22 |
1 files changed, 17 insertions, 5 deletions
diff --git a/arch/arm64/kernel/probes/decode-insn.c b/arch/arm64/kernel/probes/decode-insn.c index 3496d6169e59..6438bf62e753 100644 --- a/arch/arm64/kernel/probes/decode-insn.c +++ b/arch/arm64/kernel/probes/decode-insn.c @@ -58,10 +58,13 @@ static bool __kprobes aarch64_insn_is_steppable(u32 insn) * Instructions which load PC relative literals are not going to work * when executed from an XOL slot. Instructions doing an exclusive * load/store are not going to complete successfully when single-step - * exception handling happens in the middle of the sequence. + * exception handling happens in the middle of the sequence. Memory + * copy/set instructions require that all three instructions be placed + * consecutively in memory. */ if (aarch64_insn_uses_literal(insn) || - aarch64_insn_is_exclusive(insn)) + aarch64_insn_is_exclusive(insn) || + aarch64_insn_is_mops(insn)) return false; return true; @@ -73,9 +76,18 @@ static bool __kprobes aarch64_insn_is_steppable(u32 insn) * INSN_GOOD_NO_SLOT If instruction is supported but doesn't use its slot. */ enum probe_insn __kprobes -arm_probe_decode_insn(probe_opcode_t insn, struct arch_probe_insn *api) +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. */ @@ -133,8 +145,8 @@ enum probe_insn __kprobes arm_kprobe_decode_insn(kprobe_opcode_t *addr, struct arch_specific_insn *asi) { enum probe_insn decoded; - probe_opcode_t insn = le32_to_cpu(*addr); - probe_opcode_t *scan_end = NULL; + u32 insn = le32_to_cpu(*addr); + kprobe_opcode_t *scan_end = NULL; unsigned long size = 0, offset = 0; struct arch_probe_insn *api = &asi->api; |