From c2249707ee53b5dd696f0fae8543a754684ea04a Mon Sep 17 00:00:00 2001 From: Pratyush Anand Date: Wed, 2 Nov 2016 14:40:41 +0530 Subject: [PATCH] arm64: kprobe: protect/rename few definitions to be reused by uprobe decode-insn code has to be reused by arm64 uprobe implementation as well. Therefore, this patch protects some portion of kprobe code and renames few other, so that decode-insn functionality can be reused by uprobe even when CONFIG_KPROBES is not defined. kprobe_opcode_t and struct arch_specific_insn are also defined by linux/kprobes.h, when CONFIG_KPROBES is not defined. So, protect these definitions in asm/probes.h. linux/kprobes.h already includes asm/kprobes.h. Therefore, remove inclusion of asm/kprobes.h from decode-insn.c. There are some definitions like kprobe_insn and kprobes_handler_t etc can be re-used by uprobe. So, it would be better to remove 'k' from their names. struct arch_specific_insn is specific to kprobe. Therefore, introduce a new struct arch_probe_insn which will be common for both kprobe and uprobe, so that decode-insn code can be shared. Modify kprobe code accordingly. Function arm_probe_decode_insn() will be needed by uprobe as well. So make it global. Signed-off-by: Pratyush Anand Signed-off-by: Catalin Marinas --- arch/arm64/include/asm/probes.h | 19 ++++++++------ arch/arm64/kernel/probes/decode-insn.c | 32 ++++++++++++----------- arch/arm64/kernel/probes/decode-insn.h | 8 ++++-- arch/arm64/kernel/probes/kprobes.c | 36 +++++++++++++------------- 4 files changed, 52 insertions(+), 43 deletions(-) diff --git a/arch/arm64/include/asm/probes.h b/arch/arm64/include/asm/probes.h index 5af574d632fa..e175a825b187 100644 --- a/arch/arm64/include/asm/probes.h +++ b/arch/arm64/include/asm/probes.h @@ -17,19 +17,22 @@ #include -struct kprobe; -struct arch_specific_insn; - -typedef u32 kprobe_opcode_t; -typedef void (kprobes_handler_t) (u32 opcode, long addr, struct pt_regs *); +typedef u32 probe_opcode_t; +typedef void (probes_handler_t) (u32 opcode, long addr, struct pt_regs *); /* architecture specific copy of original instruction */ -struct arch_specific_insn { - kprobe_opcode_t *insn; +struct arch_probe_insn { + probe_opcode_t *insn; pstate_check_t *pstate_cc; - kprobes_handler_t *handler; + probes_handler_t *handler; /* restore address after step xol */ unsigned long restore; }; +#ifdef CONFIG_KPROBES +typedef u32 kprobe_opcode_t; +struct arch_specific_insn { + struct arch_probe_insn api; +}; +#endif #endif diff --git a/arch/arm64/kernel/probes/decode-insn.c b/arch/arm64/kernel/probes/decode-insn.c index d1731bf977ef..8a29d2982eec 100644 --- a/arch/arm64/kernel/probes/decode-insn.c +++ b/arch/arm64/kernel/probes/decode-insn.c @@ -78,8 +78,8 @@ static bool __kprobes aarch64_insn_is_steppable(u32 insn) * INSN_GOOD If instruction is supported and uses instruction slot, * INSN_GOOD_NO_SLOT If instruction is supported but doesn't use its slot. */ -static enum kprobe_insn __kprobes -arm_probe_decode_insn(kprobe_opcode_t insn, struct arch_specific_insn *asi) +enum probe_insn __kprobes +arm_probe_decode_insn(probe_opcode_t insn, struct arch_probe_insn *api) { /* * Instructions reading or modifying the PC won't work from the XOL @@ -89,26 +89,26 @@ arm_probe_decode_insn(kprobe_opcode_t insn, struct arch_specific_insn *asi) return INSN_GOOD; if (aarch64_insn_is_bcond(insn)) { - asi->handler = simulate_b_cond; + api->handler = simulate_b_cond; } else if (aarch64_insn_is_cbz(insn) || aarch64_insn_is_cbnz(insn)) { - asi->handler = simulate_cbz_cbnz; + api->handler = simulate_cbz_cbnz; } else if (aarch64_insn_is_tbz(insn) || aarch64_insn_is_tbnz(insn)) { - asi->handler = simulate_tbz_tbnz; + api->handler = simulate_tbz_tbnz; } else if (aarch64_insn_is_adr_adrp(insn)) { - asi->handler = simulate_adr_adrp; + api->handler = simulate_adr_adrp; } else if (aarch64_insn_is_b(insn) || aarch64_insn_is_bl(insn)) { - asi->handler = simulate_b_bl; + api->handler = simulate_b_bl; } else if (aarch64_insn_is_br(insn) || aarch64_insn_is_blr(insn) || aarch64_insn_is_ret(insn)) { - asi->handler = simulate_br_blr_ret; + api->handler = simulate_br_blr_ret; } else if (aarch64_insn_is_ldr_lit(insn)) { - asi->handler = simulate_ldr_literal; + api->handler = simulate_ldr_literal; } else if (aarch64_insn_is_ldrsw_lit(insn)) { - asi->handler = simulate_ldrsw_literal; + api->handler = simulate_ldrsw_literal; } else { /* * Instruction cannot be stepped out-of-line and we don't @@ -120,6 +120,7 @@ arm_probe_decode_insn(kprobe_opcode_t insn, struct arch_specific_insn *asi) return INSN_GOOD_NO_SLOT; } +#ifdef CONFIG_KPROBES static bool __kprobes is_probed_address_atomic(kprobe_opcode_t *scan_start, kprobe_opcode_t *scan_end) { @@ -138,12 +139,12 @@ is_probed_address_atomic(kprobe_opcode_t *scan_start, kprobe_opcode_t *scan_end) return false; } -enum kprobe_insn __kprobes +enum probe_insn __kprobes arm_kprobe_decode_insn(kprobe_opcode_t *addr, struct arch_specific_insn *asi) { - enum kprobe_insn decoded; - kprobe_opcode_t insn = le32_to_cpu(*addr); - kprobe_opcode_t *scan_end = NULL; + enum probe_insn decoded; + probe_opcode_t insn = le32_to_cpu(*addr); + probe_opcode_t *scan_end = NULL; unsigned long size = 0, offset = 0; /* @@ -162,7 +163,7 @@ arm_kprobe_decode_insn(kprobe_opcode_t *addr, struct arch_specific_insn *asi) else scan_end = addr - MAX_ATOMIC_CONTEXT_SIZE; } - decoded = arm_probe_decode_insn(insn, asi); + decoded = arm_probe_decode_insn(insn, &asi->api); if (decoded != INSN_REJECTED && scan_end) if (is_probed_address_atomic(addr - 1, scan_end)) @@ -170,3 +171,4 @@ arm_kprobe_decode_insn(kprobe_opcode_t *addr, struct arch_specific_insn *asi) return decoded; } +#endif diff --git a/arch/arm64/kernel/probes/decode-insn.h b/arch/arm64/kernel/probes/decode-insn.h index d438289646a6..76d3f315407f 100644 --- a/arch/arm64/kernel/probes/decode-insn.h +++ b/arch/arm64/kernel/probes/decode-insn.h @@ -23,13 +23,17 @@ */ #define MAX_ATOMIC_CONTEXT_SIZE (128 / sizeof(kprobe_opcode_t)) -enum kprobe_insn { +enum probe_insn { INSN_REJECTED, INSN_GOOD_NO_SLOT, INSN_GOOD, }; -enum kprobe_insn __kprobes +#ifdef CONFIG_KPROBES +enum probe_insn __kprobes arm_kprobe_decode_insn(kprobe_opcode_t *addr, struct arch_specific_insn *asi); +#endif +enum probe_insn __kprobes +arm_probe_decode_insn(probe_opcode_t insn, struct arch_probe_insn *asi); #endif /* _ARM_KERNEL_KPROBES_ARM64_H */ diff --git a/arch/arm64/kernel/probes/kprobes.c b/arch/arm64/kernel/probes/kprobes.c index f5077ea7af6d..1decd2b2c730 100644 --- a/arch/arm64/kernel/probes/kprobes.c +++ b/arch/arm64/kernel/probes/kprobes.c @@ -44,31 +44,31 @@ post_kprobe_handler(struct kprobe_ctlblk *, struct pt_regs *); static void __kprobes arch_prepare_ss_slot(struct kprobe *p) { /* prepare insn slot */ - p->ainsn.insn[0] = cpu_to_le32(p->opcode); + p->ainsn.api.insn[0] = cpu_to_le32(p->opcode); - flush_icache_range((uintptr_t) (p->ainsn.insn), - (uintptr_t) (p->ainsn.insn) + + flush_icache_range((uintptr_t) (p->ainsn.api.insn), + (uintptr_t) (p->ainsn.api.insn) + MAX_INSN_SIZE * sizeof(kprobe_opcode_t)); /* * Needs restoring of return address after stepping xol. */ - p->ainsn.restore = (unsigned long) p->addr + + p->ainsn.api.restore = (unsigned long) p->addr + sizeof(kprobe_opcode_t); } static void __kprobes arch_prepare_simulate(struct kprobe *p) { /* This instructions is not executed xol. No need to adjust the PC */ - p->ainsn.restore = 0; + p->ainsn.api.restore = 0; } static void __kprobes arch_simulate_insn(struct kprobe *p, struct pt_regs *regs) { struct kprobe_ctlblk *kcb = get_kprobe_ctlblk(); - if (p->ainsn.handler) - p->ainsn.handler((u32)p->opcode, (long)p->addr, regs); + if (p->ainsn.api.handler) + p->ainsn.api.handler((u32)p->opcode, (long)p->addr, regs); /* single step simulated, now go for post processing */ post_kprobe_handler(kcb, regs); @@ -98,18 +98,18 @@ int __kprobes arch_prepare_kprobe(struct kprobe *p) return -EINVAL; case INSN_GOOD_NO_SLOT: /* insn need simulation */ - p->ainsn.insn = NULL; + p->ainsn.api.insn = NULL; break; case INSN_GOOD: /* instruction uses slot */ - p->ainsn.insn = get_insn_slot(); - if (!p->ainsn.insn) + p->ainsn.api.insn = get_insn_slot(); + if (!p->ainsn.api.insn) return -ENOMEM; break; }; /* prepare the instruction */ - if (p->ainsn.insn) + if (p->ainsn.api.insn) arch_prepare_ss_slot(p); else arch_prepare_simulate(p); @@ -142,9 +142,9 @@ void __kprobes arch_disarm_kprobe(struct kprobe *p) void __kprobes arch_remove_kprobe(struct kprobe *p) { - if (p->ainsn.insn) { - free_insn_slot(p->ainsn.insn, 0); - p->ainsn.insn = NULL; + if (p->ainsn.api.insn) { + free_insn_slot(p->ainsn.api.insn, 0); + p->ainsn.api.insn = NULL; } } @@ -244,9 +244,9 @@ static void __kprobes setup_singlestep(struct kprobe *p, } - if (p->ainsn.insn) { + if (p->ainsn.api.insn) { /* prepare for single stepping */ - slot = (unsigned long)p->ainsn.insn; + slot = (unsigned long)p->ainsn.api.insn; set_ss_context(kcb, slot); /* mark pending ss */ @@ -295,8 +295,8 @@ post_kprobe_handler(struct kprobe_ctlblk *kcb, struct pt_regs *regs) return; /* return addr restore if non-branching insn */ - if (cur->ainsn.restore != 0) - instruction_pointer_set(regs, cur->ainsn.restore); + if (cur->ainsn.api.restore != 0) + instruction_pointer_set(regs, cur->ainsn.api.restore); /* restore back original saved kprobe variables and continue */ if (kcb->kprobe_status == KPROBE_REENTER) {