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Peter Anvin" , "Naveen N. Rao" , Thomas Gleixner , Will Deacon , "David S. Miller" , "linux-arm-kernel@lists.infradead.org" Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Tue, 20 Aug 2019 09:07:35 +0900 Masami Hiramatsu wrote: > > > Hi Jisheng, Hi, > > On Mon, 19 Aug 2019 11:37:32 +0000 > Jisheng Zhang wrote: > > > This code could be reused. So move it from x86 to common code. > > Yes, it can be among some arch, but at first, please make your > architecture implementation. After making sure that is enough > stable, we will optimize (consolidate) the code. Got it. I will duplicate the function firstly then make the consolidation as a TODO. > > For example, > > - /* Kprobe handler expects regs->ip = ip + 1 as breakpoint hit */ > > - instruction_pointer_set(regs, ip + sizeof(kprobe_opcode_t)); > > This may depend on arch implementation of kprobes. Indeed, for arm64, would be as simple as s/ip/pc. Thanks > > Could you make a copy and update comments on arm64? > > Thank you, > > > > > Signed-off-by: Jisheng Zhang > > --- > > arch/x86/kernel/kprobes/ftrace.c | 44 -------------------------------- > > kernel/kprobes.c | 44 ++++++++++++++++++++++++++++++++ > > 2 files changed, 44 insertions(+), 44 deletions(-) > > > > diff --git a/arch/x86/kernel/kprobes/ftrace.c b/arch/x86/kernel/kprobes/ftrace.c > > index c2ad0b9259ca..91ae1e3e65f7 100644 > > --- a/arch/x86/kernel/kprobes/ftrace.c > > +++ b/arch/x86/kernel/kprobes/ftrace.c > > @@ -12,50 +12,6 @@ > > > > #include "common.h" > > > > -/* Ftrace callback handler for kprobes -- called under preepmt disabed */ > > -void kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip, > > - struct ftrace_ops *ops, struct pt_regs *regs) > > -{ > > - struct kprobe *p; > > - struct kprobe_ctlblk *kcb; > > - > > - /* Preempt is disabled by ftrace */ > > - p = get_kprobe((kprobe_opcode_t *)ip); > > - if (unlikely(!p) || kprobe_disabled(p)) > > - return; > > - > > - kcb = get_kprobe_ctlblk(); > > - if (kprobe_running()) { > > - kprobes_inc_nmissed_count(p); > > - } else { > > - unsigned long orig_ip = instruction_pointer(regs); > > - /* Kprobe handler expects regs->ip = ip + 1 as breakpoint hit */ > > - instruction_pointer_set(regs, ip + sizeof(kprobe_opcode_t)); > > - > > - __this_cpu_write(current_kprobe, p); > > - kcb->kprobe_status = KPROBE_HIT_ACTIVE; > > - if (!p->pre_handler || !p->pre_handler(p, regs)) { > > - /* > > - * Emulate singlestep (and also recover regs->ip) > > - * as if there is a 5byte nop > > - */ > > - instruction_pointer_set(regs, > > - (unsigned long)p->addr + MCOUNT_INSN_SIZE); > > - if (unlikely(p->post_handler)) { > > - kcb->kprobe_status = KPROBE_HIT_SSDONE; > > - p->post_handler(p, regs, 0); > > - } > > - instruction_pointer_set(regs, orig_ip); > > - } > > - /* > > - * If pre_handler returns !0, it changes regs->ip. We have to > > - * skip emulating post_handler. > > - */ > > - __this_cpu_write(current_kprobe, NULL); > > - } > > -} > > -NOKPROBE_SYMBOL(kprobe_ftrace_handler); > > - > > int arch_prepare_kprobe_ftrace(struct kprobe *p) > > { > > p->ainsn.insn = NULL; > > diff --git a/kernel/kprobes.c b/kernel/kprobes.c > > index f8400753a8a9..479148ee1822 100644 > > --- a/kernel/kprobes.c > > +++ b/kernel/kprobes.c > > @@ -960,6 +960,50 @@ static struct kprobe *alloc_aggr_kprobe(struct kprobe *p) > > #endif /* CONFIG_OPTPROBES */ > > > > #ifdef CONFIG_KPROBES_ON_FTRACE > > +/* Ftrace callback handler for kprobes -- called under preepmt disabed */ > > +void __weak kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip, > > + struct ftrace_ops *ops, struct pt_regs *regs) > > +{ > > + struct kprobe *p; > > + struct kprobe_ctlblk *kcb; > > + > > + /* Preempt is disabled by ftrace */ > > + p = get_kprobe((kprobe_opcode_t *)ip); > > + if (unlikely(!p) || kprobe_disabled(p)) > > + return; > > + > > + kcb = get_kprobe_ctlblk(); > > + if (kprobe_running()) { > > + kprobes_inc_nmissed_count(p); > > + } else { > > + unsigned long orig_ip = instruction_pointer(regs); > > + /* Kprobe handler expects regs->ip = ip + 1 as breakpoint hit */ > > + instruction_pointer_set(regs, ip + sizeof(kprobe_opcode_t)); > > + > > + __this_cpu_write(current_kprobe, p); > > + kcb->kprobe_status = KPROBE_HIT_ACTIVE; > > + if (!p->pre_handler || !p->pre_handler(p, regs)) { > > + /* > > + * Emulate singlestep (and also recover regs->ip) > > + * as if there is a 5byte nop > > + */ > > + instruction_pointer_set(regs, > > + (unsigned long)p->addr + MCOUNT_INSN_SIZE); > > + if (unlikely(p->post_handler)) { > > + kcb->kprobe_status = KPROBE_HIT_SSDONE; > > + p->post_handler(p, regs, 0); > > + } > > + instruction_pointer_set(regs, orig_ip); > > + } > > + /* > > + * If pre_handler returns !0, it changes regs->ip. We have to > > + * skip emulating post_handler. > > + */ > > + __this_cpu_write(current_kprobe, NULL); > > + } > > +} > > +NOKPROBE_SYMBOL(kprobe_ftrace_handler); > > + > > static struct ftrace_ops kprobe_ftrace_ops __read_mostly = { > > .func = kprobe_ftrace_handler, > > .flags = FTRACE_OPS_FL_SAVE_REGS | FTRACE_OPS_FL_IPMODIFY, > > -- > > 2.23.0.rc1 > > > > > -- > Masami Hiramatsu _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel